An aircraft taxi drive system includes a motor that is configured to transfer power to an aircraft wheel via a drive chain, such that the motor rotates the aircraft wheel via the drive chain. In some examples, the drive chain is movable between first and second positions. In the first position, the drive chain, such as an exterior surface of the drive chain, is engaged with a driven sprocket that is mechanically connected to an aircraft wheel. In the second position, the drive chain is disengaged from the driven sprocket.
This disclosure relates to aircraft, and, more particularly, aircraft taxi systems.
Aircraft may perform taxiing maneuvers on the ground, e.g., travelling from a terminal to the runway or vice versa. In some systems, propulsion for the aircraft while taxiing is provided by thrust from the main engines or a tow cart.
In general, this disclosure relates to devices, systems, and techniques for taxiing an aircraft or otherwise moving the aircraft on the ground without reliance on the thrust of the main engines of the aircraft (e.g., engines used to provide thrust during flight or takeoff) to propel the aircraft. An aircraft taxi drive system that is separate from the main engines provides the energy that is used to move the aircraft on the ground. In some examples, the aircraft taxi drive system includes a motor that is configured to transfer power to an aircraft wheel via a drive chain, such that the motor rotates the aircraft wheel via the drive chain, which may result in movement of the aircraft on the ground. In some examples, the drive chain (e.g., an exterior surface of the drive chain) is configured to be disengaged from the aircraft wheel, e.g., during aircraft takeoff, landing, and other times taxiing of the aircraft is not necessary or desired, and reengaged when taxiing is desirable (e.g., after landing). In some examples, the motor and drive chain may be sized to fit on an existing land gear assembly of an aircraft, and may allow the taxi drive system to be retrofitted onto existing aircraft.
In one example, the disclosure is directed to a system comprising a motor configured to generate a mechanical output, a drive sprocket configured to be driven by the motor, a drive chain mechanically connected to the drive sprocket, an aircraft wheel and a driven sprocket mechanically connected to the aircraft wheel. The drive sprocket is configured to transfer the mechanical output from the motor to the drive chain. An exterior surface of the drive chain is configured to engage with the driven sprocket to transfer the mechanical output of the motor to the driven sprocket and the aircraft wheel. Rotation of the driven sprocket is configured to rotate the aircraft wheel.
In another example, the disclosure is directed to a system comprising means for providing a mechanical output, an aircraft wheel, means for transferring the mechanical output to the aircraft wheel, and means for moving the motor and the transferring means relative to the aircraft wheel to bring the transferring means into and out of engagement with the aircraft wheel.
In another example, the disclosure is directed to a method comprising engaging an exterior surface of a drive chain with a driven sprocket that is mechanically connected to an aircraft wheel, rotating the aircraft wheel by transferring a mechanical output of a motor to the driven sprocket and aircraft wheel via the drive chain, and disengaging the drive chain from the driven sprocket.
The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
figref[FIG. 1] is a perspective diagram illustrating an example aircraft landing gear assembly equipped with an example taxi drive system that includes a motor and drive chain.
figref[FIG. 2] is a perspective diagram illustrating the example aircraft landing gear assembly of figref[FIG. 1] with an aircraft wheel removed, and also illustrates the example taxi drive system of figref[FIG. 1] .
figref[FIG. 3] is a cutaway diagram illustrating the example aircraft landing gear assembly and taxi drive system of figref[FIG. 1] .
figref[FIG. 4] is another perspective diagram of the example aircraft landing gear assembly of figref[FIG. 1] , with an aircraft wheel removed, and the taxi drive system of figref[FIG. 1] .
figref[FIGS. 5A and 5B] are cutaway diagrams illustrating the example taxi drive system of figref[FIG. 1] in an engaged position.
figref[FIGS. 6A and 6B] are cutaway diagrams illustrating the example taxi drive system of figref[FIG. 1] in a disengaged position.
figref[FIG. 7] is a functional block diagram illustrating an example taxi drive controller.
figref[FIG. 8] is a flow diagram illustrating an example method of operating a taxi drive system.
figref[FIG. 9] is a flow diagram illustrating an example method of taxiing an aircraft with a taxi drive system that includes a motor and a drive chain that is selectively engageable with a wheel of the aircraft.
The present disclosure describes example aircraft taxi drive systems that can be used to propel an aircraft on the ground, e.g., to taxi the aircraft on the ground from one point to another. The example aircraft taxi drive system is carried by the aircraft and includes a motor that is separate from the main engines (e.g., jet engines) of the aircraft, such that the propulsion of the aircraft during taxiing is independent of the main engines used during flight. The main engines provide the thrust required during take-off of the aircraft and during flight, whereas the motor of the taxi drive system is configured to provide an output that drives an drive chain, which, when engaged with an aircraft wheel, rotates the wheel during taxiing.
In some existing aircraft taxi systems, the output of the main engines propels the aircraft during the taxiing of the aircraft. Reversing capability may be provided by thrust reversers on the one or more turbine engines of the aircraft or by reversing the pitch of the propellers on a prop plane. The low power settings for jet engines required during taxi maneuvers can be inefficient, and may result in the waste of hundreds of gallons of fuel for each modern commercial airliner every day. Further, the use of the main jet engines near the terminal and other locations may be restricted. In such situations, a tow cart may be required to maneuver the jet aircraft on the ground. The use of the tow cart to move the aircraft on the ground may consume additional manpower and require special equipment.
The example aircraft taxi drive systems described herein allows an aircraft to taxi without reliance on the aircraft main engine(s) to provide thrust or without reliance on an external device, such as a tow cart. Because the example taxi drive system has a separate motor, the aircraft may be taxied while the main engines are shutdown or at idle. With the main engines idled or shutdown, the taxi drive system allows the aircraft to maneuver under its own power, e.g., near terminal buildings at an airport. In some examples, multiple taxi drive systems may be fitted onto the aircraft, allowing directional control, e.g., through the use of differential thrust from the taxi drive system. In other configurations, the taxi drive system may be mounted on a steerable landing gear assembly.
As discussed in further detail below, the example aircraft taxi drive systems described herein are configured such that they may each be relatively easy to retrofit an existing aircraft to include such a taxi drive system, e.g., the retrofitting may not require extensive modification to the aircraft. Retrofitting existing aircraft to include a taxi drive system separate from the main engines may include various considerations. For example, retrofitting taxi drive systems onto existing aircraft without extensive modification may be limited by the dimensions of the landing gear and the landing gear bays. The taxi drive systems described herein are relatively compact, which may increase the number of types of landing gear the taxi drive system may be retrofit onto.
Compounding the design challenges faced by a taxi system is the environment the taxi system operates in. During takeoff and landing, the rotation rate of the aircraft wheels is extremely high. Thus, permanent attachment of a taxi drive system to the aircraft wheels may require mass intensive transmission or clutch systems in order to protect the taxi drive system from damage due to the torque generated by the speeds involved. The example taxi drive systems described herein is configured to engage and disengage with the aircraft wheels, e.g., by rotation or translation of the taxi drive system between a first position, in which the taxi drive system is engaged with the aircraft wheel, and a second position, in which the taxi drive system is disengaged from the aircraft wheel. In some examples, a taxi drive system includes a looped drive chain configured such that an exterior of the looped drive chain transfers torque to the aircraft wheels when the system is in the first position. By using the exterior of the drive chain loop, the drive chain loop can be relatively easily engaged or disengaged from the aircraft wheel (e.g., moved to the second position) without a complex clutch system that may be required if the interior of the loop of the drive chain was used as the engagement site.
Extra mass taken up by such a taxi drive system that includes a transmission or clutch system may decrease fuel efficiency of the aircraft and, in some cases, may reduce the passenger or cargo capability of the aircraft due to the extra space required to accommodate the taxi drive system. The example taxi drive systems described herein is able to engage or disengage as unit, allowing the use of a pivot or a translating linkage or assembly, potentially simplifying the structure and saving mass.
Also, the landing gear assembly of the aircraft may be exposed to environmental contaminants, such as dirt, melted rubber, and other contaminants. Consequently, some existing taxi drive systems that are positioned near the landing gear may be sealed from the presence of contaminants, potentially leading to a heavier taxi drive system. In contrast, the example taxi drive systems described herein may be capable of functioning robustly despite the presence of contaminants, such that enclosures for the taxi drive systems described can be, but need not be, used.
figref[FIG. 1] is a perspective diagram illustrating an example aircraft landing gear assembly 10 equipped with an example taxi drive system 24. An aircraft may be equipped with one or more landing gear assemblies 10, which can include respective one or more taxi drive systems 20 (e.g., one taxi drive system per landing gear assembly or per wheel of a landing gear assembly). In other examples, only a subset of the landing gear assemblies of an aircraft may be equipped with a respective taxi drive system 24. In the example shown in figref[FIG. 1] , landing gear assembly 10 comprises aircraft tires 12, cylinder 14, piston 16, torque arm 18, and hub 20. In addition, in the example shown in figref[FIG. 1] , taxi drive system 24 comprises plate 26, motor 28, drive chain 30, drive sprocket 32, spacers 34, actuator mount 36, and armature mount 38.
Taxi drive system 24 may be located on one or more landing gear assemblies 10. In the example shown in figref[FIG. 1] , taxi drive system 24 is installed between aircraft tires 12 opposite torque arm 18. In some examples, taxi drive system 24 may be mechanically coupled to landing gear assembly 10 via an armature, e.g., armature assembly 30 (figref[FIG. 3] ), and axle housing 22 (figref[FIG. 3] ). In other examples, taxi drive system 24 may be connected to other points on landing gear assembly 10. In addition, other mechanisms can be used to mechanically connect taxi drive system 24 to landing gear assembly 10. As discussed in further detail below, actuator mount 36 may provide a connection point allowing taxi drive system 24 to be moved between a first position, in which drive chain 30 is engaged with aircraft wheel 10, and a second position, in which drive chain 30 is disengaged from aircraft wheel 10, via armature system 44.
Two aircraft tires 12 are depicted in the example configuration of landing gear assembly 10 depicted in figref[FIG. 1] , but landing gear assembly 10 may be equipped with one or more aircraft tires 12 in other examples. Hub 20 is configured to support aircraft tires 12 on an axle (not shown) connected through axle housing 22 to piston 16. An independent braking system (not shown), e.g., a brake disc stack and brake actuator, may be co-located with taxi drive system 24 on (e.g., directly or indirectly mechanically connected to) landing gear assembly 10 at or near aircraft tires 12. In other examples, taxi drive system 24 may be located on one or more landing gear assemblies 10 while an independent braking system may be equipped on other landing gear assemblies of the aircraft. In some examples, one or more of landing gear assemblies 10 may be steerable to provide directional control over the taxiing aircraft. In addition, or instead, steering for the taxiing aircraft may be controlled by using differential braking or differential thrust from multiple landing gear assemblies 10 equipped with respective taxi drive systems 20.
Cylinder 14 and piston 16 may be configured to provide shock absorption for landing gear assembly 10. Cylinder 14 may, for example, comprise a hydraulic cylinder in some examples. In these examples, upon impact with the ground during landing, aircraft tires 12 may drive piston 16 into cylinder 14, increasing the hydraulic pressure within the landing gear system. The motion of hydraulic fluid through cylinder 14, caused by the pressure of landing, may absorb at least some of the impact of the landing and slow the movement of piston 16 into cylinder 14. In the example shown in figref[FIG. 1] , torque arm 18 is a jointed arm connected to cylinder 14 and a point at the base of piston 16, e.g., at axle housing 22 for the axle supporting aircraft tires 12. Torque arm 18 is jointed, which allows piston 16 to extend and retract relative to cylinder 14 with the takeoff and landing of the aircraft, while also helping to prevent piston 16 from rotating in cylinder 14, thereby maintaining the alignment of the aircraft tires 12 with the direction of travel of the aircraft.
Motor 28 is configured to provide motive force to taxi drive system 24 by rotating drive sprocket 32. Drive sprocket 32 may be engaged with drive chain 30, which may form a loop that is configured to surround drive sprocket 32. As drive sprocket 32 rotates, the loop formed by drive chain 30 also moves. When taxi drive system 24 is in a first position, driven sprocket 42, which is mechanically connected to hub 20, is engaged with the exterior of the loop formed by drive chain 30. Driven sprocket 42 is mechanically connected to hub 20 such that as driven sprocket 42 rotates, hub 20 rotates (e.g., driven sprocket 42 can be in a fixed position relative to hub 20). Thus, as the loop formed by drive chain 30 moves, the motion is transferred to driven sprocket 42 (figref[FIG. 2] ) and aircraft tires 12, causing the aircraft to taxi. Because drive chain 30 is only engaged with a part of driven sprocket 42 and does not loop around driven sprocket 42, the concern that drive chain 30 may come loose from sprocket 42 is minimized; as discussed below, an actuation system or the like holds drive chain 30 in engagement with driven sprocket 42, and may also hold taxi drive system 24 in a fixed position relative to driven sprocket 42 in both the first and second positions.
In situations when taxi drive system 24 may be exposed to relatively high torques or rotation rates from aircraft tires 12, taxi drive system 24 may be configured to move to a second position, e.g., rotated or pivoted out of engagement with driven sprocket 42, such that drive chain 30 does not engage with driven sprocket 42. Taxi drive system 24 may be reengaged with driven sprocket 42 to taxi the aircraft by moving taxi drive system 24 to the first position in which drive chain 30 is engaged with driven sprocket 42.
Motor 28 is configured to generate torque that can be used to propel the aircraft when the aircraft is on the ground, e.g., to taxi the aircraft. Motor 28 can be powered using any suitable source. In some examples, motor 28 may comprise or consist of an electric motor. Power for an electric motor may be drawn from any suitable source, such as directly from the electrical system of the aircraft, e.g., the auxiliary power unit (APU) of the aircraft, and routed along landing gear assembly 10, or from a battery or other power source of taxi drive system 10 and separate from the main electrical system of the aircraft. An APU may be configured to provide energy for functions other than propulsion of the aircraft, such as to start the main engines or to power lights on the aircraft. In other examples, motor 28 may be powered by a fuel, such as, for example the aviation fuel used to power the main engine (s) of the aircraft during flight. In some examples, a fuel line supplying motor 28 may be routed along landing gear assembly 10, e.g., the fuel line may traverse from the aircraft fuselage to motor 28 along landing gear assembly 10. In addition or instead, motor 28 may be a hydraulic motor powered by, for example, the hydraulic system of the aircraft. In other configurations taxi drive system 24 may have an independent electricity, hydraulic fluid, or fuel source located on landing gear assembly 10 or the fuselage of the aircraft.
In some, but not all, examples, motor 28 may include a transmission or gear box, which may help increase the torque outputted by motor 28 to drive sprocket 32. The gear ratio in the gearbox or transmission may be fixed or selectable, e.g., via crew member input. In some examples, the rotation rate of motor 28, and, therefore, the rate at which wheel 12 is rotated by motor 28, may be controlled by crew member input. For example, if motor 28 comprises an electric motor, a crew member of the aircraft may control the rotation rate of motor 28, and speed of the taxiing aircraft, by varying the voltage or current supplied to motor 28. Motor 28 may be used to taxi in reverse by reversing the polarity of the voltage or current supplied to motor 28.
Motor 28 can be mechanically connected to drive sprocket 32 using any suitable configuration. In the example shown in figref[FIG. 1] , plate 26 supports motor 28, drive sprocket 32, and spacers 34, e.g., motor 28, drive sprocket 32, and spacers 34 may be directly or indirectly mechanically connected to a surface of plate 26. Accordingly, in the example shown in figref[FIG. 1] , motor 28 is mechanically connected to drive sprocket 32 via plate 26 in the example shown in figref[FIG. 1] . In some examples, plate 26 may hold motor 28, drive sprocket 32, and idler sprockets 40 (figref[FIG. 2] ) in fixed positions relative to each other. In other configurations, plate 26 may be configured to allow one or more of drive sprocket 32 or idler sprockets 40 to translate relative to each other, allowing the tension in drive chain 30 to be adjusted or engaged/disengaged with driven sprocket 42. Plate 26 may be configured to withstand the forces generated by the interaction of drive chain 30, idler sprockets 40, and the landing gear assembly 10 of the aircraft. Plate 26 may be constructed of any suitable material, such as, but not limited to, an alloy of aluminum or steel.
As discussed in further detail below, plate 26 provides a relatively simple and lightweight mechanism by which taxi drive system 24 can be moved between a first position and a second position because, in some examples, movement of plate 26 causes movement of drive chain 30 away from driven sprocket 42.
In some examples, plate 26 may be paired with a second plate that is positioned on the other side of drive chain 30 from plate 26, such that the opposing plates enclose drive chain 30 and help prevent drive chain 30 from slipping off of idler sprockets 40 and drive sprocket 32 by limiting the potential movement of drive chain 30 relative to drive sprocket 32 and idler sprockets 40. In addition, in some examples, plate 26 may help prevent the passage of environmental contaminants to drive chain 30 and drive sprocket 32 by at least partially covering chain 30 and sprocket 32. In some examples, additional plating may be added to form a container around drive chain 30, and one side may be left exposed provide room for drive chain 30 to engage with driven sprocket 42 of landing gear assembly 10.
Drive chain 30 may be mechanically connected to drive sprocket 32, e.g., looped around drive sprocket 32 such that at least some of the teeth of drive sprocket 32 engage with drive chain 30. For example, teeth of drive sprocket 32 may be positioned within gaps defined by drive chain 30 (e.g., holes in the links of a chain). In some examples, taxi drive system 24 includes spacers 34, which are configured to help prevent drive chain 30 from loosening or sliding out of engagement with drive sprocket 32. Spacers 34 may also support a second plate 26 (not shown) that, together with plate 26, sandwiches drive sprocket 32 and drive chain 30, which may further help prevent drive chain 30 from slipping loose from drive sprocket 32. Spacers 34 may comprise any suitable material, for example, an alloy of steel, aluminum, or titanium.
Drive chain 30 may be made of any suitable material, for example an alloy of steel or titanium. Drive chain 30 may form a loop, encompassing drive sprocket 32 and idler sprocket 40 (figref[FIG. 2] ). Drive chain 30 may comprise engagement sites located on both the interior and exterior surfaces of the loop formed by drive chain 30, surface 30A and 30B (figref[FIG. 2] ) respectively. An interior surface of the loop may face drive sprocket 32 while an exterior surface may face away from drive sprocket 32. Engagement sites on the interior of the loop formed by drive chain 30 may allow drive sprocket 32 to engage with, and transfer power through, drive chain 30 by pulling and/or rotating drive chain 30. Engagement sites on the exterior of the loop formed by drive chain 30 may allow driven sprocket 42 (figref[FIG. 2] ) to engage with, and be driven by, drive chain 30. The engagement sites of drive chain 30 may, for example, be formed by the links of drive chain 30. Other types of drive chains are contemplated. For example, in some examples, drive chain 30 may comprise a flexible belt and engagement sites may be provided by raised teeth on both sides of the belt.
As discussed above, motor 28 is configured to rotate drive sprocket 32. In some examples, drive sprocket 32 may be mechanically connected to motor 28, and an incorporated transmission or gearbox, if present, via a drive shaft that penetrates through plate 26. The drive shaft may be configured to transfer the rotational output of motor 28, and any incorporated gear box/transmission, to drive sprocket 32. Drive sprocket 32 may have one or more sets of teeth that are configured to engage with drive chain 30. Drive chain 30 and sprocket 32 may be configured to remain engaged with each other during operation of taxi drive system 24, and, in some examples, when taxi drive system 24 is in both the first and second positions. For example, in some examples, drive chain 30 may be prevented from slipping off drive sprocket 32 by tension in the loop formed drive chain 30 around drive sprocket 32 and idler sprockets 40 (figref[FIG. 2] ). In some examples, a second plate positioned on the other side of drive chain 30 from plate 26 may also prevent drive chain 30 from slipping out of engagement with drive sprocket 32 by sandwiching drive sprocket 32, and drive chain 30, between plate 26 and the second plate.
Spacers 34 may provide support and spacing to allow drive sprocket 32 and idler sprockets 40 to rotate between two plates 26. In the example shown in figref[FIG. 1] , spacers 34 guide drive chain 30 around drive sprocket 32 and idler sprockets 40 by pinching the sides of the loop formed by drive chain 30 inwards, forcing drive chain 30 to engage a larger portion of the circumference of drive sprocket 32 than would be engaged with a taut loop stretched from drive sprocket 32 to idler sprockets 40. Increasing the portion of drive sprocket 32 engaged with drive chain 30 may reduce the amount of wear on drive sprocket 32 and drive chain 30 as well as decrease the incidence of slippage between drive sprocket 32 and drive chain 30.
Drive chain 30 may be brought into and removed from engagement with driven sprocket 42, i.e., moved between first and second positions. In the disengaged position (also referred to herein as the second position for ease of description), the teeth of driven sprocket 42 may not contact the engagement sites on the exterior of the loop formed by drive chain 30. Drive chain 30 may move into the disengaged position by rotating or translating taxi drive system 24 as a unit by an actuation system. Similarly, drive chain 30 may be brought into engagement with driven sprocket 42 (moved to the first position) by translating or rotating taxi drive system 24 as unit until the teeth of driven sprocket 42 meshes with the exterior of the loop formed by drive chain 30.
Actuator mount 36 provides a connection point for an actuation system, e.g., a hydraulic ram, electric ballscrew, or acme lead screw drive, that mechanically connects to taxi drive system 24. Aircraft tires 12 may rotate at relatively high speeds during takeoff and landing of the aircraft, e.g., based on movement of the aircraft primarily or solely attributable to the main engines of the aircraft. Thus, at some points during operation of the aircraft, aircraft tires 12 may be driven by forces not generated by taxi drive system 24. Transmission of the high rotating speeds to taxi drive system 24 may affect the integrity of the taxi drive system 24, such as by causing drive chain 30 and drive sprocket 32 to rotate at relatively high speeds. To help reduce or even prevent transmission of high rotating speeds of aircraft tires 12, e.g., during takeoff and landing of the aircraft, to taxi drive system 24, taxi drive system 24 may be selectively engaged and removed from engagement (i.e., disengaged) with driven sprocket 42 and aircraft tires 12.
In some examples, taxi drive system 24 is movable between a first position, in which drive chain 30 is engaged with driven sprocket 42, and a second position, in which drive chain 30 is disengaged from driven sprocket 42, by an actuator connected to actuator mount 36. When drive chain 30 is disengaged from driven sprocket 42, rotation of drive chain 30 by drive sprocket 32 is not translated to driven sprocket 42, such that driven sprocket 42 does not rotate with drive chain 30. In some examples, motor 28, drive sprocket 32, drive chain 30, plate 26, and idler sprockets 40 may be moved between the first and second positions as a single unit. For example, motor 28, drive sprocket 32, drive chain 30, plate 26, and idler sprockets 40 may have fixed positions relative to each other and may be movable relative to driven sprocket 42. In other examples, only a part of taxi drive system 24 may be moved between the first and second positions, e.g., only plate 26 (and, therefore, drive chain 30 and drive sprocket 32).
In some examples, taxi drive system 24 may pivot into and out of engagement with driven sprocket 42. In the example shown in figref[FIG. 1] , force applied, for example by a hydraulic ram or other actuator (e.g., hydraulic ram 48 (figref[FIG. 3] ) or an electric screw drive), at actuator mount 36 may cause taxi drive system 24 to rotate about a pivot, e.g., armature mount 38, and engage or disengage with driven sprocket 42. In some examples, actuator mount 36 may be located on the casing of motor 28. In other examples, actuator mount 36 may be located on plate 26. In other examples, taxi drive system 24 may be translated radially or linearly into and out of engagement with driven sprocket 42. Instead, or in addition, taxi drive system 24 may be translated radially, e.g., translated along a radius of driven sprocket 42, into or out of engagement.
Armature mount 38 provides a connection point for a support linking taxi drive system 24 to landing gear assembly 10. Armature mount 38 may be configured to provide a pivot point about which taxi drive system 24 may be rotated between a first position, in which drive chain 30 is engaged with driven sprocket 42, and a second position, in which drive chain 30 is disengaged from driven sprocket 42, by an actuator connected to actuator mount 36. In other examples, armature mount 38 may provide a connection between taxi drive system 24 and a linear bearing system, or other translation means, allowing taxi drive system 24 to be maneuvered into and out of engagement with driven sprocket 42. In some examples, armature mount 38 may be located on the casing of motor 28. In other examples, armature mount 38 may be located on plate 26.
Landing gear assembly 10 may have other configurations in other examples. For example, landing gear assembly 10 can include other types of tire and hub arrangements, other axle arrangements, and the like. Taxi drive system 24 can be used with any suitable aircraft landing gear assembly 10.
figref[FIG. 2] is a perspective diagram illustrating aircraft landing gear assembly 10, with an aircraft tire 12 removed, and taxi drive system 24. As shown in figref[FIG. 2] and described above with respect to figref[FIG. 1] , hub 20 supports aircraft tire 12. Hub 20 may be mechanically connected to driven sprocket 42, which is depicted in figref[FIG. 2] as being engaged with drive chain 30 (e.g., taxi drive system 24 is in the first position), causing hub 20 and aircraft tire 12 to rotate with driven sprocket 42. Hub 20 may also be connected to an axle linking the pair of aircraft tires 12 and hubs 20, e.g., through axle housing 22 (figref[FIG. 3] ) at the base of piston 16. Driven sprocket 42 may be mechanically connected to hub 20 using any suitable technique.  As an example, driven sprocket 42 may be machined as part of hub 20. In other examples, driven sprocket 42 may be physically separate from hub 20 and mechanically connected to hub 20, e.g., bolted or riveted to hub 20, or connected to hub 20 via the axle supporting hub 20 and aircraft tires 12. Other configurations are also contemplated.
Also shown in figref[FIG. 2] are idler sprockets 40, which are mounted on plate 26. Taxi drive system 24 can include one or more idler sprockets 40. As discussed above with respect to figref[FIG. 1] , idler sprockets 40 are configured to engage with drive chain 30 to help maintain tension of drive chain 30 to allow driven sprocket 42 to engage drive chain 30. In addition, idler sprockets 40 can help shape the loop formed by chain 30 and expand or shrink the loop of drive chain 30 to change the length of drive chain 30 that is configured to engage with driven sprocket 42. In some cases, it may be desirable to maximize a length of drive chain 30 that engages with driven sprocket 42 may increase the life span of drive chain 30 and driven sprocket 42, as well as reduce the possibility of drive chain 30 slipping out of engagement with driven sprocket 42. In other cases, it may be desirable to reduce the length of drive chain 30 that engages with driven sprocket 42 in order to reduce the total size of taxi drive system 24 and may ease the engagement/disengagement of drive chain 30 with driven sprocket 42. Idler sprockets 40 may rotate under the influence of drive sprocket 32 and drive chain 30.
In the example depicted in figref[FIG. 2] , idler sprockets 40 are depicted positioned in a triangular arrangement with drive sprocket 32 at an apex and the base of the triangle oriented towards driven sprocket 42. This arrangement may prevent drive chain 30 from impinging on itself as drive chain 30 flexes towards drive sprocket 32 when chain 30 is brought into engagement with driven sprocket 42. In other examples, idler sprockets 40 may also be located at the position of spacers 34, which may help shape the path the loop of drive chain 30 follows and increase the proportion of drive sprocket 32 engaged with drive chain 30. In other examples, a single idler sprocket may be used to expand drive chain 30 to allow the exterior of drive chain 30 to be brought into engagement with driven sprocket 42.
Idler sprockets 40 may be configured to translate to maintain tension in drive chain 30, for example idler sprockets 40 may be mounted on a spring tensioned pivot arm (not shown). A minimum tension on drive chain 30 to prevent drive chain 30 from coming loose from idler sprockets 40 or drive sprocket 32 may be maintained. Other techniques can be used in addition to or instead of idler sprockets 40 in order to maintain contact between idler sprockets 40 and drive chain 30. For example, a tooth size of idler sprockets 40 may be selected to enable idler sprockets 40 to maintain contact with drive chain 30. In addition, or instead, a second plate 26 may sandwich drive chain 30 between a first plate 26 and help prevent disengagement with idler sprockets 40 and drive sprocket 32.
Driven sprocket 42 is configured to transfer the mechanical output of motor 28, transmitted via drive chain 30, to aircraft tire 12. In the example shown in figref[FIG. 2] , driven sprocket 42 is larger than drive sprocket 32, which may increase the torque outputted to aircraft tires 12. The size of driven sprocket 42 and driven sprocket 42 may be specific to the type of aircraft taxi drive system 24 is used with, and can be influenced by factors such as gear ratio, sprocket tooth stress, velocity limits for drive chain 30, and access restrictions around existing equipment in landing gear assembly 10. Driven sprocket 42 is depicted as equipped with a double row of teeth in figref[FIG. 2] . In other configurations, driven sprocket 42 may have one or more rows of teeth sized to engage with drive chain 30. Drive chain 30 may flex during engagement with driven sprocket 42 to partially follow the curvature of driven sprocket 42. By flexing to follow the curve of driven sprocket 42, drive chain 30 may reduce the individual stress on the teeth of driven sprocket 42, thereby helping to increase the life of driven sprocket 42 and reducing chances of slippage between driven sprocket 42 and drive chain 30.
A taxi drive system 24 equipped with drive chain 30 that is configured to engage with driven sprocket 42 may be advantageous over some geared drive systems in which two sprockets engage with each other to transfer mechanical output from a motor to aircraft tire 12. For example, the gear drive systems may require tighter tolerances in spacing of the teeth between gears than a drive chain-sprocket mesh requires, which may require the control of the gear drive system to be more precise (e.g., thereby increasing the cost of the taxi drive system). Further, the gear drive systems may require more extensive lubrication and contaminant protections than system 24 including drive chain 30. In addition, because drive chain 30 is relatively flexible relative to driven sprocket 42, the amount of wear to drive chain 30 and driven sprocket 42 due to relative motion between drive chain 30 and driven sprocket 42 during operation of the taxi drive system may be reduced relative to the amount of wear between two sprockets that more directly engage with each other (e.g., by meshing teeth).
figref[FIG. 3] is a cutaway diagram illustrating an aircraft landing gear assembly 10 equipped with a taxi drive system 24. Taxi drive system 24 is equipped with an armature system 44, which supports taxi drive system 24 and allows taxi drive system 24 to be moved between the first and second positions. In the example shown in figref[FIG. 3] , armature system 44 comprises armature 46, hydraulic ram 48, piston mount 50, axle mount 52, and front support 54. Taxi drive system 24 is depicted as being connected to armature system 44 via armature mount 38 as a pivot. In other examples, taxi drive system 24 may be slidably connected to armature system 44 such that taxi drive system 24 can be linearly moved between the first and second position, or armature system 44 may radially translate taxi drive system 24 towards and away from driven sprocket 42. The pivot and radial translation may require less room for movement of taxi drive system 24 than the linear system.
Landing gear assembly 10 may comprise an axle housing 22 located at the base of piston 16. Axle housing 22 may support an axle (not shown) connecting aircraft tires 12 via respective hubs 20. Torque arm 18, depicted partially cutaway in figref[FIG. 3] , may connect cylinder 14 (figref[FIG. 1] ) to the base of piston 16 and axle housing 22, preventing the rotation of piston 16 in cylinder 14 while allowing piston 16 to retract into cylinder 14 during landing. The joint between the upper and lower sections ( 18A and 18B respectively) of torque arm 18 is visible in figref[FIG. 3] . The lower section of torque arm 18 is depicted in figref[FIG. 3] as pivotably connected to axle housing 22. In other embodiments, torque arm 18 may be connected to other locations on piston 16.
Taxi drive system 24 is in the first position in figref[FIG. 3] , in which drive chain 30 is engaged with driven sprocket 42 in figref[FIG. 3] . Armature 46 may comprise one or more rigid members extending below axle housing 22 and piston 16 to provide support for taxi drive system 24. Taxi drive system 24 and armature 46 may be pivotably connected via armature mount 38. In other examples, armature 46 may comprise a linkage allowing armature 46 to extend and retract, translating taxi drive system 24 radially into and out of engagement with driven sprocket 42. In further examples, taxi drive system 24 may be slidably connected to armature 46, allowing taxi drive system 24 to be translated radially or linearly into and out of engagement with driven sprocket 42 (e.g., between the first and second positions).
Armature 46 may be rigidly coupled to landing gear assembly 10. As depicted in figref[FIG. 3] , armature 46 may be connected to piston 16 via piston mount 50 and axle mount 52. By coupling armature 46 to landing gear assembly 10, armature 46 and taxi drive system 24 may be retrofitted onto existing aircraft landing gear 10 without requiring modification to the size and other components of aircraft landing gear 10.
In examples in which taxi drive system 24 pivots between the first and second positions, hydraulic ram 48 may provide the force that causes taxi drive system 24 to pivot between the first and second positions, into and out of engagement with driven sprocket 42. Hydraulic ram 48 may comprise actuator cylinder 48A and actuator piston 48B. Hydraulic ram 48 may be pivotably connected to armature 46 and actuator mount 36. In other configurations hydraulic ram 48 may be pivotably connected to front support 54. In some examples, hydraulic ram 48 may comprise a double acting hydraulic actuator. Hydraulic fluid may be routed through feed lines located on, for example, landing gear assembly 10 and connected to the hydraulic system of the aircraft. In other examples, another suitable mechanism in addition to or instead of hydraulic ram 48 can be used to pivot taxi drive system 24 between the first and second positions. For example, a pneumatic piston or an electric drive actuator, such as an electric ballscrew or acme lead screw drive, can be used to pivot taxi drive system 24 between the first and second positions.
Piston mount 50 is configured to couple armature assembly 30 to landing gear assembly 10 so that taxi drive system 24 is supported. Piston mount 50 may comprise a collar bolted around or otherwise attached to piston 16 above axle housing 22. Piston mount 50 may comprise two sections bolted or welded together, allowing piston mount 50 to be retrofitted onto existing landing gear assemblies. Piston mount 50 may connect to armature 46 via front support 54, providing support for armature 46 under the weight of taxi drive system 24 and torque loads resulting from rotating driven sprocket 42 and aircraft tires 12.
Axle mount 52 is configured to provide additional support to armature assembly 30 and taxi drive system 24, mechanically coupling armature assembly 30 to landing gear assembly 10 and helping to prevent or control motion of armature assembly 30. Axle mount 52 may be mechanically coupled to axle housing 22 and extend a rigid member radially away from axle housing 22 to connect to armature 46. In some examples, axle mount 52 may be rigidly connected to landing gear assembly 10. In other examples, axle mount 52 may be pivotably coupled to both armature 46 and axle housing 22. Pivotably coupling axle mount 52 to axle housing 22 may allow axle mount 52 to rotate and move armature 46, resulting in taxi drive system 24 being translated into and out of engagement with driven sprocket 42.
Front support 54 is configured to support armature 46 by linking armature 46 to piston mount 50. Front support 54 may comprise a rigid member connecting piston mount 50 and armature 46. Front support 54 may be rigidly connected to piston mount 50 and armature 46, providing support to armature 46 and taxi drive system 24. In some examples, front support 54 may be manufactured as part of armature 46. In addition, in some examples, front support 54 may be pivotably connected to armature 46 and piston mount 50, allowing armature 46 to translate taxi drive system 24 into and out of engagement with driven sprocket 42. Front support 54 may provide a mounting point for hydraulic ram 48.
figref[FIG. 4] is a perspective diagram illustrating aircraft landing gear assembly 10 and taxi drive system 24. One aircraft tire 12 of landing gear assembly 10 is not shown in figref[FIG. 4] , exposing taxi drive system 24 and armature system 44. In the example shown in figref[FIG. 4] , taxi drive system 24 is in the first position, such that drive chain 30 is engaged with driven sprocket 42.
As depicted in figref[FIG. 4] , some examples of armature system 44 may comprise one or more frames and bracings to increase the strength and stability of armature system 44 while minimizing weight. Armature system 44 may comprise armature 46, hydraulic ram 48, and axle mount 52. Piston mount 50 (figref[FIG. 3] ) and front support 54 (figref[FIG. 3] ) are not visible in figref[FIG. 4] . As shown in figref[FIG. 4] , armature 46 may comprise one or more rigid members 46A connected to axle mount 52 and armature mount 38. Armature 46 may further comprise bracing members 46B which form a frame with rigid members 46A, and may prevent armature 46 from flexing under the weight and torque of taxi drive system 24. The frames formed by one or more rigid members 46A and 46B may be connected together. Armature 46 may mechanically connect to, or be manufactured including, front support 54. Front support 54 may mechanically connect armature 46 to piston mount 50. Piston mount 50 may be bolted or otherwise mechanically connected to piston 16 or axle housing 22, linking armature 46 to landing gear assembly 10. Axle mount 52 may be coupled to axle housing 22 and provide further support for armature 46. Hydraulic ram 48, or another actuator type, may be mechanically coupled to piston mount 16, armature 46, or front support 54, and may be configured to apply a force at actuator mount 36 that causes taxi drive system 24 to move between the first and second positions.
figref[FIGS. 5A and 5B] are cutaway diagrams illustrating taxi drive system 24 in the first position, in which drive chain 30 is engaged with driven sprocket 42 that is mechanically connected to hub 20. figref[FIG. 5A] depicts taxi drive system 24 and armature system 44, with landing gear assembly 10 removed, as viewed from the interior of the landing gear. Taxi drive system 24 is engaged with driven sprocket 42 and may transfer torque to aircraft wheel 12 to allow an aircraft to taxi.
In figref[FIG. 5A] , taxi drive system 24 is shown in the first (engaged) position. In the first position of taxi drive system 24, the teeth of driven sprocket 42 mesh with drive chain 30 and drive chain 30 pulls against the teeth of driven sprocket 42. To move system 24 into the first position by bringing drive chain 30 into engagement with driven sprocket 42, hydraulic ram 48 may retract and pull taxi drive system 24 from the second (disengaged) position to the first position.
figref[FIG. 5B] depicts taxi drive system 24 in the first position, in which drive chain 30 is engaged position with driven sprocket 42. An aircraft tire 12 is removed to better show the workings of taxi drive system 24. The perspective of the diagram is from the exterior of the landing gear system and in a direction substantially parallel to the axis of rotation of wheel 12.
In some examples, taxi drive system 24 may be rotated into engagement with driven sprocket 42. For example, taxi drive system 24 may pivot about armature mount 38 as force from hydraulic ram 48 is applied. In other configurations, taxi drive system 24 may be translated into and out of the first and second positions. In some examples, armature system 44 may comprise a linear bearing or bale that, when actuated, retracts, pulling drive system 24 into contact with driven sprocket 42, such that drive chain 30 meshes with driven sprocket 42. In addition, or alternatively, axle mount 52 may be pivotably coupled to armature 46 and axle housing 22. As axle mount 52 rotates away from taxi drive system 24, armature 46 is pulled towards landing gear assembly 10 and brings taxi drive system 24 towards driven sprocket 42. Front support 54 may be pivotably coupled armature 46 and piston mount 50, supporting armature 46 while allowing armature 46 to translate under influence of axle mount 52. Taxi drive system 24 may be rigidly coupled to armature 46, as the motion of armature 46 may be sufficient to bring taxi drive system 24 into engagement. A brace extending, for example, between actuator mount 36 and armature 46 or front support 54 may further support taxi drive system 24.
As discussed in further detail below, in some examples, prior to being moved into the first position, taxi drive system 24 may be activated to rotate drive chain 30, such that drive chain 30 is rotating when it is brought into engagement with driven sprocket 42. This may help reduce wear on drive chain 30 during engagement.
In some examples, idler sprockets 40 or spacers 34 may be movable to maintain a constant tension in drive chain 30. By using movable spacers 34 or idler sprockets 40 drive chain 30 may be installed in taxi drive system 24 with some slack. In the first (engaged) position, the slack in the loop formed by drive chain 30 is taken up by driven sprocket 42 impinging on the loop. By allowing drive chain 30 to conform to a portion of the curve of driven sprocket 42, the contact area and number of teeth of driven sprocket 42 engaged with drive chain 30 may increase, which may help reduce wear on drive chain 30 and driven sprocket 42. As taxi drive system 24 is disengaged, the slack in drive chain 30 may be taken up by movable idler sprockets 40 or spacers 34.
figref[FIGS. 6A and 6B] are cutaway diagrams illustrating a taxi drive system 24 in the second position. figref[FIG. 6A] depicts taxi drive system 24 in the second position. The perspective of figref[FIG. 6B] is substantially similar to that of figref[FIG. 5B] . An aircraft tire 12 is removed from figref[FIGS. 6A and 6B] to better show the workings of taxi drive system 24.
In the disengaged position, as shown in figref[FIG. 6A] , driven sprocket 42 and aircraft tires 12 rotate without influence from the influence of taxi drive system 24. The teeth of driven sprocket 42 do not mesh with drive chain 30. To move system 24 from the first position and into the second, hydraulic ram 48 may extend and push taxi drive system 24 into the second (disengaged) position from the first position. This may help limit or even eliminate the transfer of high rotational speeds of aircraft tires 12 (e.g., during takeoff and landing) to taxi drive system 24.
In other examples, taxi drive system 24 may be translated out of engagement with driven sprocket 42. For example, axle mount 52 may be pivotably coupled to axle housing 22 and armature 46. As axle mount 52 rotates towards taxi drive system 24, armature 46 may be forced to translate away from landing gear assembly 10 and move taxi drive system 24 out of engagement with driven sprocket 42. In other examples, armature 46 may comprise one or more linear bearings or bales that may extend and remove taxi drive system 24 from engagement with driven sprocket 42.
Because a force is no longer applied against drive chain 30 by driven sprocket 42 when taxi drive system 24 is in the second (disengaged) position, the loop formed by drive chain 30 may straighten at the site of the former engagement with driven sprocket 42, as shown in figref[FIG. 6B] . Tension in drive chain 30 may be maintained by idler sprockets 40 or spacers 34. For example, spacers 34 or idler sprockets 40 may shift to maintain tension. As an example, spacers 34 may be mounted on a pivot arm such that spacers 34 shift inwards, pinching drive chain 30 around drive sprocket 32, extending the path drive chain 30 travels around drive sprocket 32 and idler sprockets 40. In addition or instead, idler sprockets 40 may translate outwards, extending the distance between idler sprockets 40 and drive sprocket 32. In the disengaged position, driven sprocket 42 and aircraft tires 12 are free to rotate without interference from taxi drive system 24.
figref[FIG. 7] is a schematic functional block diagram illustrating an example taxi drive controller 56, which is configured to control the operation of taxi drive system 24. Taxi drive controller can be located on an aircraft that includes taxi drive system 24, and may, for example, be implemented as part of the flight control hardware, software, firmware, firmware or stand-alone cockpit interface/controller hardware, firmware, hardware, or any combination thereof. In the example shown in figref[FIG. 7] , taxi drive controller 56 comprises processor 62, actuator controller 64, and motor controller 66. As shown in figref[FIG. 7] , taxi drive controller 56 can be configured to receive user input via user interface 58 and signals from speed sensor 60 and output commands to hydraulic ram 48 (or other actuator) and motor 28 to control ram 48 and motor 28.
Taxi drive controller 56 comprises any suitable arrangement of hardware, alone or in combination with software and/or firmware, to perform the techniques attributed to taxi drive controller 56 and taxi drive system 24. In various examples, taxi drive controller 56 can include any one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. Although not shown in figref[FIG. 7] , taxi drive system 24 may also include a memory, which include any volatile or non-volatile media, such as a random access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, and the like. The memory may store instructions for execution by taxi drive controller 56 that cause taxi drive controller 56 to perform the techniques attributed to taxi drive controller 56 herein. Although processor 62, actuator controller 64, and motor controller 66 are described and illustrated as separate modules of taxi drive controller 56, in some examples, processor 62, actuator controller 64, and motor controller 66 can be functionally integrated. In some examples, processor 62, actuator controller 64, and motor controller 66 correspond to individual hardware units, such as ASICs, DSPs, FPGAs, or other hardware units.
Taxi drive controller 56 is configured to receive user input via user interface 58 via wired or wireless communication. User interface 58, may be, for example, onboard the aircraft (e.g., in a cockpit of the aircraft) or remotely located. User interface 64 may include, for example, input buttons and/or a keypad and a display (e.g., a cathode ray tube (CRT) display, a liquid crystal display (LCD) or light emitting diode (LED) display). The keypad may take the form of an alphanumeric keypad or a reduced set of keys associated with particular functions. User interface 58 can additionally or alternatively include a peripheral pointing device, such as a mouse, via which a user may interact with user interface 58. Other examples of user input mechanism of user interface 58 include, but are not limited to, a joystick, a switch, a throttle, or a steering wheel/yoke inputs. In some examples, a display of user interface 58 may include a touch screen display, and a user may interact with controller 56 via the display.
User interface 58 is configured to receive input from a user, such as a pilot or crew of the aircraft, indicating various inputs for controlling taxi drive system 24. User interface 58 may provide the input to processor 62 of taxi drive controller 56 as, for example, electrical or optical signals. The user input can indicate, for example, a desired rotational speed of aircraft tires 12, allowing the user to control the speed of the taxiing aircraft via taxi drive system 24, or directional input, allowing the user to control the direction of the taxiing aircraft via taxi drive system 24, e.g., via differential steering using multiple taxi drive systems 24.
The user input received by processor 62 of controller 56 via user interface 58 may also comprise input indicating whether taxi drive system 24 should be moved to the first or second positions (e.g., input indicating whether taxiing of the aircraft is desirable). Thus, as shown in figref[FIG. 7] , in some examples, processor 62 can control actuator controller 64 to control hydraulic ram 48 (or another mechanism in other examples) to move taxi drive system 24 between the first and second positions, depending on the received user input.
Taxi drive controller 56 is also configured to receive input from speed sensor 60, which may be configured to generate a signal indicative of the rotation rate of driven sprocket 42. Speed sensor 60 may, for example, directly measure the rotation rate of driven sprocket 42 or may measure the rotation rate of a component connected to driven sprocket 42, such as hub 20, aircraft tire 12, or the axle supporting hub 20. In other examples, speed sensor 60 may measure the velocity of the aircraft. Speed sensor 60 may be included in taxi drive system 24 or the output from an existing wheel speed sensor in landing gear assembly 10 of the aircraft may be used. Processor 62 may receive the signal from speed sensor 60 and determine the rotation rate of driven sprocket 42 and the rotation rate of motor 28 that enables drive chain 30 to match the cross-radial velocity of driven sprocket 42.
Processor 62 of taxi drive controller 56 is configured to control motor 28 via motor controller 66. Motor 28 can be controlled, for example, to control the speed of taxiing of the aircraft. Thus, processor 62 can control motor controller 66 in some examples in response to user input received via user interface 58, where the user input may request an increase or decrease in speed of the taxiing aircraft. In some examples, processor 62 may determine the appropriate rotation rate of motor 28 based on the user input and control motor controller 66 to control motor 28 via the voltage supplied to motor 28, or by actuating a throttle or selecting a gear ratio of motor 28 or a transmission/gearbox incorporated into motor 28. In order to determine the appropriate rotation rate of motor 28, processor 62 may, for example, reference a look-up table or another data structure that associates a plurality of aircraft taxiing speeds with respective rotation rates of motor 28.
In some examples, processor 62 is configured to move taxi drive system 24 between the first and second positions in response to user input received via user interface 58. In other examples, processor 62 is configured to automatically move taxi drive system 24 between the first and second positions in response to a detected condition. For example, processor 62 can control actuator controller 64 to move aircraft taxi system 24 from the first position to the second position in response to detecting an aircraft speed greater than or equal to a stored threshold. The aircraft speed can be determined, for example, based on the signal generated by speed sensor 60. As another example, processor 62 can control actuator controller 64 to move aircraft taxi system 24 from the second position to the first position in response to detecting an aircraft speed less than or equal to a stored threshold.
Taxi drive controller 56 can be configured to control multiple taxi drive systems 24 of an aircraft, which can be installed on multiple landing gear assemblies, e.g., on the main landing gear of an aircraft. For example, processor 62 can independently control the rotation rates of the motors 28 of each of the taxi drive systems, thereby allowing the aircraft to be steered using the differential in rotation rates. In some examples, processor 62 can control into rotation rates for multiple taxi drive systems in order to steer the aircraft and taxi the aircraft at the speed, e.g., indicated by the user input based on user input received via user interface 58. Processor 62 can control the rotation rate of motor 28 (or multiple motors of respective taxi drive systems 24), and, therefore, the speed of the aircraft during taxiing, thereby allowing the speed of the aircraft during taxi to be controlled without reliance on aircraft friction brake systems, although the friction brake system could also be used.
figref[FIG. 8] is a flow diagram illustrating an example method of operation of taxi drive system 24. The method shown in figref[FIG. 8] includes rotating drive chain 30, e.g., to a speed that is based on a rotation of aircraft tire 12 ( 80), engaging taxi drive system 24 ( 82), taxiing aircraft ( 84), and disengaging taxi drive system 24 ( 86). Engaging or disengaging taxi drive system 24 ( 82, 86, respectively) may comprise pivoting taxi drive system 24 or translating taxi drive system 24.
In the example shown in figref[FIG. 8] , drive chain 30 can be rotated prior to engaging drive chain 30 with driven sprocket 42 ( 80). As discussed above, this may help reduce wear of drive chain 30 and/or driven sprocket 42 attributable to the friction between drive chain 30 and driven sprocket 42 as they are brought into engagement with each other. Processor 62 of taxi drive controller 56 can, for example, control motor controller 66 to rotate drive chain 30 to a speed that is based on a speed of aircraft tire 12, and, in some examples, is substantially equal to or equal to the speed of the aircraft tire 12. An example taxi drive system 24 may match the rotation rate of aircraft tire 12 within 10 revolutions per minute (rpm) or approximately 10 rpm. The disengaged drive chain 30 may be rotated at a slightly greater speed than driven sprocket 42 if aircraft tire 12 is rotating during engagement. The speed of the aircraft wheel can be determined using any suitable technique. In some examples, speed sensor 60 (figref[FIG. 7] ) may be positioned to measure the rotation rate of aircraft tire 12, hub 20, or driven sprocket 42, while in other examples, existing wheel speed sensors aboard the aircraft may be used to monitor the rotation rate of aircraft tire 12, hub 20, or driven sprocket 42. Taxi drive controller 56 (figref[FIG. 7] ) may receive the output of speed sensor 60 to determine the cross-radial velocity of the teeth of driven sprocket 42 based on the radius and the angular velocity/rotational frequency of driven sprocket 42. Taxi drive controller 56 may then control motor 28 and drive chain 30 based on the determined speed, e.g., to substantially match or match the cross-radial velocity of the teeth of driven sprocket 42.
One method of determining the rotation rate of drive sprocket 32 that may produce the velocity of drive chain 30 that matches the cross-radial velocity of driven sprocket 42 is to use the ratio of radius of driven sprocket 42 to drive sprocket 32 multiplied by the rotational frequency of driven sprocket 42. These calculations may be performed automatically by taxi drive controller 56 (e.g., processor 62 or another component) of taxi drive system 24 or the avionics of the aircraft. Upon determining a rotational rate for taxi drive system 24, the determined rotational rate may be used by taxi drive controller 56 to control motor controller 66 to accelerate motor 28 to the selected rotational rate before bringing taxi drive system 24 into engagement with driven sprocket 42.
In some examples, engaging taxi drive system 24 ( 82), i.e., moving taxi drive system to the first position, may comprise pivoting taxi drive system 24 into engagement with driven sprocket 42. Processor 62 of taxi drive controller 56 may, for example, control actuator controller 64 (figref[FIG. 7] ) to control hydraulic ram 48 (figref[FIGS. 3 and 7] ) to pivot taxi drive system 24 to the first position. Hydraulic ram 78 may be pivotably coupled to actuator mount 36 and armature 46 or front support 54. By retracting hydraulic ram 48, taxi drive system 24 may be pulled about armature mount 38 and into engagement with driven sprocket 42. Actuators that can be used instead of, or in addition to, hydraulic ram 48 include, but are not limited to, pneumatic pistons and electric drives, such as a ballscrew or acme lead screw drive. Pneumatic pistons may operate in a similar manner to hydraulic ram 48, using a double action cylinder to retract a piston and pull taxi drive system 24 into engagement. Electric screw drives may comprise a threaded rod and a threaded engagement device (e.g., a nut). Either the threaded rod or the threaded engagement device may be connected to taxi drive system 24. A motor may rotate the threaded rod or threaded engagement device. As the threaded rod or threaded engagement device rotates, the interaction of the threading produces a force that may pull taxi drive system 24 into the first position, such that drive chain 30 is engaged with driven sprocket 42.
In other examples, taxi drive controller 56 can engage taxi drive system 24 ( 82) by at least translating taxi drive system 24 into engagement with driven sprocket 42. For example, armature 46 (figref[FIG. 3] ) may support or comprise a linear bearing system or other device configured to pull taxi drive system radially from a disengaged position into engagement with driven sprocket 42, and processor 62 of taxi drive controller 56 can control actuator controller 64 to move armature 46 in order to engage drive chain 30 with driven sprocket 42. In other examples, armature 46 may be pivotably connected to front support 54 (figref[FIG. 3] ) and axle mount 52 (figref[FIG. 3] ). Front support 54 may be pivotably connected to piston mount 50 (figref[FIG. 3] ). A hydraulic actuator or motor may rotate axle mount 52 causing armature 46 to be pulled back, bring taxi drive system 24 into engagement with driven sprocket 42.
After engagement with driven sprocket 42, taxi drive system 24 may be used to taxi the aircraft ( 84). Under the control of processor 62, motor controller 66 can control motor 28 (figref[FIG. 2] ) to rotate drive sprocket 32, driving drive chain 30 and rotating driven sprocket 42. Driven sprocket 42 may be connected to hub 20 (figref[FIG. 1] ), causing aircraft tire 12 to rotate with driven sprocket 42. Motor controller 66 of taxi drive controller 56 (figref[FIG. 7] ) may control motor 28 to generate a rotational rate determined, e.g., based on user input received via user interface 58 from a user (e.g., a pilot) regarding the desired speed of taxiing of the aircraft. Motor 28 may be equipped with a transmission or gear box. A transmission system may allow the gear ratio between drive sprocket 32 and motor 28 to be adjusted, which can adjust the rotational rate of motor 28.
In preparation for takeoff, landing, or when idle, taxi drive controller 56 can control taxi drive system 24 to be disengaged ( 86), i.e., moved to the second position. Disengagement may be controlled by actuator controller 64 of taxi drive controller 56 (figref[FIG. 7] ) and may occur automatically or in response to user input 58. In some examples, processor 62 may control actuator controller 64 to disengage taxi drive system 24 by at least pivoting taxi drive system 24 out of engagement with driven sprocket 42. In one example, hydraulic ram 48 may extend, pushing taxi drive system 24 around armature mount 38 and clear of the teeth of driven sprocket 42. In the disengaged position aircraft tires 12 may rotate free of interaction with taxi drive system 24. Other configurations may use a pneumatic piston or electric screw drive in place of hydraulic ram 48.
In other examples, processor 62 may control actuator controller 64 to disengage taxi drive system 24 ( 86) by at least translating taxi drive system 24 out of engagement with driven sprocket 42. Armature 46 may support one or more hydraulic pistons, pneumatic rams, linear bearings, or similar devices configured to push taxi drive system 24 radially out of engagement with driven sprocket 42. Other examples may comprise rotating axle mount 52 to drive armature 46 towards taxi drive system 24. As armature 46 may be pivotably coupled to axle mount 52 and front support 54 (and piston mount 50 via front support 54), the motion of axle mount 52 may cause armature 46 to swing taxi drive system 24 out of engagement with driven sprocket 42.
figref[FIG. 9] is a flow diagram illustrating an example method for using taxi drive system 24. The method shown in figref[FIG. 9] may comprise engaging taxi drive system 24 ( 82), spinning-up aircraft tire 12 ( 90), disengaging taxi drive system 24 ( 86), braking aircraft to safe speed ( 92), rotating drive chain 30 prior to engaging drive chain 30 with driven sprocket 42 ( 80), engaging taxi drive system 24 ( 82), taxiing aircraft ( 84), and disengaging taxi drive system 24 ( 86).
Taxi drive system 24 is configured to be disengaged prior to take off and landing. In some examples, taxi drive controller 56 (figref[FIG. 7] ), as directed by user input receive via user interface 58 (figref[FIG. 7] ), may control taxi drive system 24 to temporarily bring drive chain 30 into engagement with driven sprocket 42 prior to landing ( 82). For example, taxi drive system 24 may be used to “spin-up” aircraft tire 12 prior to touch down ( 90). Spinning up aircraft tire 12 prior to touch down comprises causing aircraft tire 12 to rotate at a relatively high speed, e.g., at or near the rate that aircraft tire 12 will rotate after impact with the runway. This may, for example, reduce the wear on the aircraft tires 12 by reducing the amount of skid on the runway resulting from a near stationary aircraft tire 12 being forced to suddenly rotate at speed. Taxi drive system 24 may be configured to rotate aircraft tire 12 at a higher rate for spin-up than for because the inertia of the aircraft may not encumber the ability of motor 28 to provide the desired output as much during spin-up compared to during taxiing. After obtaining the desired rotational rate during spin up, taxi drive controller 56 may cause taxi drive system 24 to be disengaged from driven sprocket 42, protecting drive chain 30 from being inadvertently rotated by contact with driven sprocket 42 during landing ( 86).
Upon landing, the aircraft may use thrust reversers and friction brakes to slow the aircraft ( 92). Once the aircraft has reached a desired speed threshold, e.g., approximately 25 knots, taxi drive controller 56 may control taxi drive system 24 to be moved to the first position, in which drive chain 30 is engaged with driven sprocket 42 ( 82). As discussed above with respect to figref[FIG. 8] , motor 28 may rotate drive chain 30 may be rotated to a speed that is based on a rotation rate of aircraft tires 12 or the current ground speed of the aircraft ( 80). By rotating drive chain 30 prior to engaging drive chain 30 with driven sprocket 42, wear and impact on taxi drive system 24 and driven sprocket 42 during engagement may be reduced. The wear and impact on taxi drive system 24 from being brought into engagement with driven sprocket 42 may be particularly low when drive chain 30 is rotated to a speed that substantially matches or matches the rotation rate of aircraft tires 12 or the current ground speed of the aircraft prior to engaging drive chain 30 with driven sprocket 42.
After matching rotation rates, taxi drive system 24 may be brought into engagement with driven sprocket 42 ( 82), e.g., under the control of taxi drive controller 56 of taxi drive system 24 or the avionics of the aircraft, and the aircraft may then begin taxiing under power from taxi drive system 24 ( 84). The speed at which the aircraft taxis may be controlled by the rotation rate of motor 28, and, in some examples, the selection of a gear ratio within the gear box or transmission of motor 28. The aircraft may be slowed by decreasing the rotation rate of motor 28 and/or using a braking mechanism, such as a brake disc stack. Directional control may be provided by installing taxi drive system 24 on multiple landing gear and rotating aircraft tires 12 at different rates on different landing gear, e.g., differential steering. In other examples, taxi drive system 24 may be installed on steerable landing gear assembly, for example the nose wheel of an aircraft. The steerable landing gear may be turned in the desired direction and taxi drive system 24 will apply force in the direction the steerable landing gear is oriented, causing the aircraft to turn. The rotational rate of taxi drive system 24 may be controlled by commands from the pilot or other crew member in the aircraft. These commands may be routed into the avionics of the aircraft or to taxi drive controller 56 of taxi drive system 24 which controls the rotation rate of motor 28.
Taxi drive system 24 may be disengaged from driven sprocket 42, i.e., moved to the second position ( 86), e.g., for maintenance, when aircraft is idling, or in preparation for takeoff. Maintenance may be facilitated by removing drive chain 30 from engagement with driven sprocket 42, removing the interference of driven sprocket 42 with the inspection or removal of drive chain 30. Prior to takeoff taxi drive system 24 may be disengaged to prevent affecting the integrity of system 24 from the relatively high rotational rates aircraft tires 12 may experience during the takeoff run. In some examples, taxi drive controller 56 can disengage taxi drive system 24 from driven sprocket 42 in response to a command from the pilot or a crew member of the aircraft. The command may be transmitted to the avionics of the aircraft or a processing component of taxi drive system 24 via user interface 58. In some examples, controller 56 can automatically cause taxi drive system 24 to be disengaged based on the rotation rate of aircraft tires 12 or driven sprocket 42 or based on exceeding a ground speed threshold (e.g., 25 knots or another predetermined operating speed) or increasing the throttle past a threshold indicating impending takeoff.
Various examples of the invention have been described. These and other examples are within the scope of the following claims.


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A basic end-to-end implementation of charts for your application, based on data from the object demo.
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{% block page_head %}
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A basic end-to-end implementation of charts for your application,
based on data from the object demo.
Charts Example
Budget by Department
Average Salary by Department


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- How does ASX collect Personal Information?
- How does ASX use and disclose Personal Information?
- Does ASX transfer Personal Information overseas?
- Does ASX collect sensitive information and use of Government Identifiers?
- How does ASX manage Personal Information?
- How to access your Personal Information?
- Web site collection and Direct Marketing
- Notification of Collection of Personal Information
- Links to other Sites
- Contact Us
- Updates to this Privacy Statement
Why does ASX collect Personal Information?
As a listed entity, market operator and CS facility operator, ASX has certain statutory obligations imposed on it under the Corporations Act. Under ASX’s Operating Rules, ASX may collect, use and disclose Personal Information in order to be able to effectively discharge these obligations.
As a receiver and provider of services to third parties, ASX may be required to collect, use and disclose Personal Information to discharge contractual obligations and in relation to potential employees during the recruitment process.
How does ASX collect Personal Information?
The type of Personal Information ASX collects may include: names, addresses, contact details, occupations and any other information required to meet contractual obligations and statutory obligations as a market operator and CS Facility operator, in the provision of services or in relation to recruitment.
Personal Information is collected in a variety of ways, including by way of personal contact such as business activities and events, as well as mail, telephone, email and internet. In some circumstances the ASX Group may be provided Personal Information about an individual from a third party.
We may collect Personal Information about:
- Individuals;
- Shareholders;
- Suppliers;
- Employees;
- Listed entities, Participants and Issuers;
- Candidates for employment;
- Potential new Participants/clients;
- Third parties seeking services; and
- Other people who come into contact in the ordinary course of business.
Please note: Personal information is collected by ASX to facilitate the effective provision of a service or product. Failure to provide this information to ASX is likely to prevent ASX from being able to effectively process and respond to you.
How does ASX use and disclose Personal Information?
ASX may use or disclose Personal Information for the following purposes:
- To enable it to discharge its statutory obligations;
- To enable it to discharge its licence obligations as a market operator and as a clearing and settlements facility;
- To enable it to discharge its contractual obligations when providing products and services to third parties;
- To provide investor education services;
- To service shareholders;
- To service ASX customers;
- To provide administration for ASX employees;
- To enable the resolution of a concern or complaint;
- To provide ongoing information about our products and services to people that we believe may be interested;
- To consider applications for employment; and
- To provide products and services.
ASX will only use your Personal Information for the purpose for which you have provided it. We will not disclose your Personal Information to third parties, unless you consent or in other circumstances where such disclosure is required or authorised by law.
Contracts we enter into with other parties for the provision of services may require us to disclose your Personal Information to them. In those cases, our contracts require other parties providing services to us to observe the terms of this Privacy Policy.
Does ASX transfer Personal Information overseas?
ASX does not generally transfer personal information to overseas parties unless required by law or enforcement activity or unless working with international service providers. ASX may exchange or store personal information with vendors who have been contracted to provide customer relationship systems and technological solutions. These third party service providers may be located in Australia, USA, Japan and other countries. While these parties will be subject to confidentiality, they are not required to comply with the Australian Privacy Act and may have different disclosure requirements under their local laws. Although information is encrypted where possible and efforts are made to protect your information, when you agree to this Privacy Policy you acknowledge that the ASX will not be responsible for the overseas third party. The list of countries may change from time to time.
Does ASX collect sensitive information and use of Government Identifiers?
ASX does not collect sensitive information about an individual unless the individual has consented or it is required by law. Sensitive information covers Personal Information such as an individual’s race or ethnic origin; political opinions, membership of a political association; religious beliefs or affiliations; philosophical beliefs; membership of a professional or trade association membership of a trade union; sexual preferences and practices; criminal record; or health information.
Government identifiers (eg TFNs) will generally not be used unless required by law or necessary to complete a transaction or service.
How does ASX manage Personal Information?
ASX takes reasonable steps to protect Personal Information it holds from misuse, interference and loss and from unauthorised access, modification or disclosure. Where Personal Information is no longer required for the purpose for which it was collected reasonable steps will be taken to destroy or permanently de-identify the information. Unsolicited Personal Information received from third parties that does not serve an appropriate purpose will be destroyed.
Personal Information is held for a period of up to seven years, depending on the nature of the information being held.
How to access your Personal Information?
ASX will take reasonable steps to ensure that Personal Information held about you is accurate, complete and up to date. You may request access or correction to Personal Information held by the ASX by writing to the Chief Privacy Officer. Exceptions may apply as outlined in the APPs. A fee may be charged for providing access.
Web site collection and Direct Marketing
ASX Group collects Personal Information from the web site www.asx.com.au through receiving subscriptions or registration of courses, games and services. Cookies are used on the web site in the following ways:
- To authenticate access to certain areas of the web site, such as MyASX section, the customer portal and ASXOnline;
- To monitor traffic levels and flows; and
- From time to time ASX may conduct surveys
Information is recorded into our server log which is provided by your browser. This information is logged for statistical purposes only. Where possible, ASX will use pseudo names to protect an individual’s anonymity. However, there will be circumstances where ASX will not be able to provide a service unless your personal information is provided.
We will try not to identify you except, in the event of an investigation, where a law enforcement agency may exercise a warrant to inspect the service provider’s logs; if your usage is causing technical issues for our website which may need to be resolved; or where you may have won in a game. In these circumstances, we may need to identify you to contact you. We will review browsing activities to be able to provide better products and services and ASX partners with Dianomi for ad serving. For more information on ad serving and information on ‘Opting-out’ please visit http://www.dianomioffers.co.uk/legal/privacy.epl.
We may also from time to time email you about an event or new feature/service that we think might be of interest. If you do not wish to receive such emails, all you have to do is unsubscribe or opt-out.
Notification of Collection of Personal Information
ASX will notify you at the time of collecting Personal Information. The Notification of Collection statement covers the following:
“This information is collected by ASX to facilitate the provision of a product or service. Failure to provide this information to ASX is likely to prevent ASX from being able to offer you the product or service. Should you wish to, you can access the information you provide to ASX by contacting the ASX. ASX may from time to time use external service providers but will not disclose personal information you provide to any other organisations or individuals, unless required or authorised by law to do so or unless you consent to the disclosure. ASX does not generally provide personal information to overseas parties but does use international service providers for technological solutions. If you would like to contact us or lodge a complaint please refer to the ASX's Privacy Policy for further details.”
Links to other Sites
This site links to other sites. ASX is not responsible for the privacy practices or the content of such web sites.
Contact Us
Address:
ASX Limited
Level 6
20 Bridge Street
SYDNEY NSW 2000
Telephone: 131 279
Email<EMAIL_ADDRESS>You can also obtain information at the Office of the Australian Information Commissioner’s website at www.oaic.gov.au
Updates to this Privacy Statement
This Privacy Statement will be reviewed from time to time as required.
Dated: December 2015


Preparation time
less than 30 mins
Cooking time
1 to 2 hours
Serves
Makes 12 mini cakes or 1 large cake
Dietary
This recipe makes 12 mini cakes which are perfect for special occasions or afternoon tea, but if you prefer you can make one large cake instead.
Equipment and preparation: for this recipe you will need a 12 cup mini sandwich tin, a blender and a piping bag.
Preheat the oven to 180C/350F/Gas 4.
In a bowl, cream together the butter and sugar until pale.
Beat in the eggs one at a time, then fold in the orange zest and juice. Add the vanilla paste and flour. Mix well and spoon or pipe the mixture into mini sandwich tins. Bake in the oven for 15-20 minutes. When golden-brown and cooked through, set aside to cool on a wire cooling rack.
For the praline, in a heavy-based saucepan set over a low heat, add the sugar and a tablespoon of water and heat until the sugar has dissolved. Once dissolved, increase the temperature and bring to a gentle boil until it reaches 160-175C/320-350F (use a sugar thermometer for this). Take off the heat and plunge the base of the pan into a basin of cool water to prevent the caramel burning.
For the decoration, set aside 8-12 hazelnuts (depending on how many mini cakes you are making – you need one per cake). Stick each nut onto a cocktail stick and dip them into the caramel to coat. Set aside on a baking tray to cool.
Add the remaining hazelnuts to the caramel and pour an even layer onto a sheet of non-stick parchment or silicone sheet. Set aside to cool completely then break into chunks. Transfer to a blender and pulse to form a coarse powder.
Meanwhile make the ganache. Melt the chocolate and butter together in a microwave or a heatproof bowl set over a pan of simmering water (Without letting the base of the bowl touch the water). When the chocolate has melted and the butter is fully incorporated, add the cream. Mix well and at this point you can refrigerate it until needed.
For the sponges, when the mini cakes are cool, cut them in half horizontally and fill with a little whipped cream. Then coat all over with the chocolate ganache, reserving some for the topping (if the ganache is too thick, warm it a little to loosen).
Coat the mini cakes in the crushed praline and then pipe the remaining ganache on top in a neat mound.
Decorate the tops of the cakes with raspberries and the caramel-coated hazelnuts.


Head Blacksmith Newyear:
In the heart of the Ruins of Pavel there is a Dwarven barracks. There you will find my associate,
Collector Yumi
. She'll give you a job if you tell her I sent you.


Productivity
Done. Done. Done.
Next?
Everything Apple makes works together simply and seamlessly so you can focus on what matters. Start a project on iPad and finish it on Mac. Tweak your presentation on iPhone just before class. Mix, match, find your flow and own your learning.
Productivity
Done. Done. Done.
Next?
Everything Apple makes works together simply and seamlessly so you can focus on what matters. Start a project on iPad and finish it on Mac. Tweak your presentation on iPhone just before class. Mix, match, find your flow and own your learning.
Productivity
Done. Done. Done.
Next?
Everything Apple makes works together simply and seamlessly so you can focus on what matters. Start a project on iPad and finish it on Mac. Tweak your presentation on iPhone just before class. Mix, match, find your flow and own your learning.
Productivity
Done. Done. Done.
Next?
Everything Apple makes works together simply and seamlessly so you can focus on what matters. Start a project on iPad and finish it on Mac. Tweak your presentation on iPhone just before class. Mix, match, find your flow and own your learning.


PICTURE PERFECT (20th Century Fox) Starring: Jennifer Aniston, Jay Mohr, Kevin Bacon, Olympia Dukakis, Illeana Douglas, Kevin Dunn. Screenplay: Arleen Sorkin & Paul Slansky and Glenn Gordon Caron. Producer: Erwin Stoff. Director: Glenn Gordon Caron.  Reviewed by Scott Renshaw.
[Overheard in the rec room at the Old Chestnuts Rest Home for Over-Worked Film Premises in Boca Raton, Florida:]
MISMATCHED BUDDY ACTION COMEDY: Hey, D. H., I hear we may be getting a new arrival soon.
DIE HARD-IN-A-CONFINED-SPACE THRILLER: I don't know, Buddy, it feels pretty cramped around here as it is.
BUDDY: Well, this one definitely needs a break. The name is Romantic Comedy Where a Couple Pretends to Be Together for an Ulterior Motive, or some such.
D. H.: That's a mouthful.
BUDDY: Yeah, and she's been a busy little thing. CAN'T BUY ME LOVE, GREEN CARD, PRETTY WOMAN, HOUSESITTER...why, she even showed up in a cameo already this summer, in MY BEST FRIEND'S WEDDING. The latest is called PICTURE PERFECT, starring that darling little Jennifer Aniston from "Friends."
D. H.: She's a looker, all right.
BUDDY: She plays an unmarried advertising executive named Kate Mosley who is feeling pressure from every direction to settle down. Her mother (Olympia Dukakis) nags her, her boss (Kevin Dunn) suggests that only "stable" employees will get the choice assignments, and the office Lothario (Kevin Bacon), who gets Kate all hot and bothered, is only interested in girls who are unavailable.
D. H.: Sounds like young Kate needs a mate, or at least the appearance of one.
BUDDY: You guessed it, D. H. Enter Nick (Jay Mohr), a nice young fellow with whom Kate had a picture taken at a wedding. Everyone is led to believe that Nick is Kate's long-distance fiance, which works out fine until Nick becomes a minor celebrity and everyone wants to meet him. So Kate finds Nick and asks him to play the part. And predicaments ensue.
D. H.: Predicaments...ha! Running through broken glass in bare feet from armed terrorists, now _that's_ a predicament.
BUDDY: Yes, well...anyway, Miss Aniston is fetching enough in the lead role, with that kind of frazzled charm Sandra Bullock turned into stardom. The script by Arleen Sorkin, Paul Slansky and Glenn Gordon Caron has a few clever moments, and Caron's direction is well-paced. What really makes it worth a look is an engaging, low-key performance by Jay Mohr as Nick. It's uncommon to find an actor who can make earnestness interesting, or who can make an audience root for him by sheer force of his good nature, despite an under-written role. And we know that's not the only angle Mohr can work, since he did a fine job of playing a completely slime in JERRY MAGUIRE.
D. H.: Well, then, what's the problem?
BUDDY: The problem, as we both know, is that a script has to be better than that to keep audineces watching when you know exactly how the story is going to end. It's only a matter of time before the two phony lovers figure out they should be real lovers, and someone learns an Important Lesson along the way. Actually, everyone in PICTURE PERFECT learns an Important Lesson along the way, undergoing an 11th hour conversion so that there isn't a single moderately unlikeable character remaining by the closing credits. Only Mohr seems like a genuinely decent person; everyone else reads the lines of a genuinely decent person because the formula demands it.

BUDDY: Sorry. Anyway, it's a cute enough little picture, but it strains that thin premise to its limits. She could certainly stand a few months here.
D. H.: I have to agree with you there.
BUDDY: You see, even though we seem completely different, I knew we had something in common all along.
D. H.: Yippee-ki-yay, mother...
On the Renshaw scale of 0 to 10 old chestnuts: 6.
Visit Scott Renshaw's MoviePage http://www.inconnect.com/~renshaw *** Subscribe to receive new reviews directly by email! See the MoviePage for details, or reply to this message with subject line "Subscribe".
The review above was posted to the
rec.arts.movies.reviews newsgroup (de.rec.film.kritiken for German reviews).
The Internet Movie Database accepts no responsibility for the contents of the
review and has no editorial control. Unless stated otherwise, the copyright
belongs to the author.
Please direct comments/criticisms of the review to relevant newsgroups.
Broken URLs inthe reviews are the responsibility of the author.
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Related links: index of all rec.arts.movies.reviews reviews


Our unique approach to transportation logistics provides personalized service, a safety-first commitment, and the flexibility to meet any supply chain challenge. If that approach makes sense to you as well, give us a call or email us using the form below.


My favorite things
These are a few of my favorite things.
(You're singing now, aren't you?)
People
Here are some of my favorite people!
- My hubbie Grant
- My bestie Megan
- My dad Kevin
- My brother and sister-in-law, Elliott and Claire
Flavors of ice cream
These are my three favorites, in order:
- Chocolate chip cookie dough
- Cookies and Cream
- Mint chocolate chip
Thanks for reading about me!


DVM develops, designs, engineers and installs water conservation and desinfection systems for your property. The technology we implement is an innovative water conservation system that focuses on meeting a facilities goals in reducing gallons per minute being used.
The savings have been recorded up to 23.5% of the overall water usage. Our systems are legally recognized by the local governing bodies and installed compliance with local and federal codes accompanied with permits and engineered drawings.
DVM Water Systems are custom design for each application to address the needs for each unique facility. RThis system will reduce the gallons per minute used throughout your entire water system. The system is automated and intelligent with built in fail safes to guaranty 100% up-time, and continuous monitoring to ensure water safety levels, possible leaks and savings.
DVM Water Systems GPM 2K series is an innovative water conservation system that focuses on meeting a facilities goals in reducing gallons per minute being used. The savings have been recorded up to 23.5% of the overall water usage. The GPM 2K series is designed as an intelligent water conservation system that adjusts to changes in the current water pressure and reducing any unnecessary amounts of water into the facility at any given time.
Furthermore, the system will alert you of any possible water leaks, monthly savings and added options to control remote shut offs in case of excessive water leaks or flooding.


First Name
Last Name
Sports Fashion Movies Food
Male Female
Freshman Sophomore Junior Senior
Republican Democrat Independent I don't know


class Gem::Resolver::Molinillo::Resolver
This class encapsulates a dependency resolver. The resolver is responsible for determining which set of dependencies to activate, with feedback from the {#specification_provider}
Attributes
resolver_ui[R]
@return [UI] the UI module used to communicate back to the user
during the resolution process
specification_provider[R]
@return [SpecificationProvider] the specification provider used
in the resolution process
Public Class Methods
new(specification_provider, resolver_ui)
click to toggle source
Initializes a new resolver. @param [SpecificationProvider] #specification_provider
see {#specification_provider}
@param [UI] #resolver_ui
see {#resolver_ui}
# File lib/rubygems/resolver/molinillo/lib/molinillo/resolver.rb, line 25 def initialize(specification_provider, resolver_ui) @specification_provider = specification_provider @resolver_ui = resolver_ui end
Public Instance Methods
resolve(requested, base = DependencyGraph.new)
click to toggle source
Resolves the requested dependencies into a {DependencyGraph}, locking to the base dependency graph (if specified) @param [Array] requested an array of 'requested' dependencies that the
{#specification_provider} can understand
@param [DependencyGraph,nil] base the base dependency graph to which
dependencies should be 'locked'
# File lib/rubygems/resolver/molinillo/lib/molinillo/resolver.rb, line 36 def resolve(requested, base = DependencyGraph.new) Resolution.new(specification_provider, resolver_ui, requested, base). resolve end


This program plots measurements (linears or planes) onto a map. Data can be entered in the following ways:
1)manual input
2)from a file
3)from a sample map
4)from an Excel file
The program needs the coordinates of the data points (geographic coordinates as dd°mm.mmm',or dd°mm'ss.s''),
Gauss-Krueger coordinates or UTM-Coordinates), and azimut
and dip angle of the measures, together
with a symbol for linears or planes.
Measures can be entered using a 0..360°
or 0..400gon scale. Input from a file
is always
with 0..360°.
For manual input and input from a map, the sectors (NE, SE, SW, NW) are
needed to find the geographic
coordinates.
NE means northern latitude and eastern longitude, the other sectors are
used in a similar sense.


Canopy Height Models¶
An integral part of any analysis is the production of a canopy height model, or CHM. The CHM is a rasterized representation of the canopy of the forest. The creation and filtering of CHMs play a large role in tree detection algorithms and are an interpretable way to display information.
A basic canopy height model can be created using a convenience wrapper:
tile = pyfor.cloud.Cloud('my_tile.las')
tile.normalize(1)
chm = tile.chm(0.5)
The above block will load the las file, my_tile.las, remove the ground elevation (normalize) and compute a basic canopy height model. Here, we specify a resolution of 0.5 units.
Note: In pyfor no assumptions are made about the reference system, so always specify resolutions in the units that the point cloud is registered in. In this case it was originally registered in meters, therefore the output raster will have a resolution of 0.5 meters.
Manipulating Canopy Height Models¶
Often times, raw CHMs are not adequate for analysis. They contain many issues, such as missing values and data pits. We can add some extra arguments to add NaN interpolation and pit filtering.
better_chm = tile.chm(0.5, interp_method = "nearest", pit_filter = "median")
Here, we interpolate missing values using a nearest neighbor interpolator, and pass a median filter over the canopy height model to smooth pits.
We can display our CHM with the .plot method:
better_chm.plot()
Writing Canopy Height Models¶
A canopy height model is a Raster object. And can be written out in the same way.
better_chm.write('my_chm.tif')


The test contains 10 questions and there is no time limit.The test is just a nice way to see how much you know or dont about javaScript.
Start the Quiz
Good luck!
JavaScript is a:
Which of the following is not javaScript Data type?
Which of these is not looping structure in javaScript?
Which of the following is type of pop up in javaScript?
Find one type of error in javaScript?
How are object properties assigned ?
Which of the following function of String object returns a string representing the specified object?
How can a value be appended to an array in a given manner-?
What is the method for reading and writing a file in JavaScript?
What does the following statement declares var myArray=[[[]]]?


The purpose of this course is to provide an understanding of how data and statistical analysis
can improve managerial decision-making. Students will learn how to ask well-posed questions, collect or find relevant data,
and apply appropriate statistical methods to solve problems and make better business and policy decisions. Together, we will
explore statistical methods for gleaning insights from economic and social data, with an emphasis on approaches to
identifying casual relationships. We will also discuss how to design and analyze randomized
experiments and introduce econometric methods for estimating casual effects in non-experimental data.
Satisfies: 2 units; the statistics req. for admission into Haas (taken in conjunction with Data 8)
Prerequisites: concurrent enrollment in Data 8 or previous completion of Data 8 and one semester of
calculus (not strictly enforced, but highly recommended)
Skills you'll gain: further experience with JupyterHub (a tool growing in popularity), comfort with
interpreting and analyzing economic and social data (using Python in particular), knowing when and how to apply standard
casual inference methods