Multiple maneuvering systems for various applications

The multiple maneuvering systems for various applications includes several embodiments of wheeled, multiple maneuvering systems including multiple parallel maneuvering systems (MPMS). Each MPMS includes two or more parallel maneuvering units (PMUs) attached to one another by a connecting structure. Each PMU includes two or more powered or non-powered wheels, with the wheels being maintained parallel to one another by a steering mechanism. The steering mechanism may include gears, belt and pulley, chain and sprocket, or a rigid linkage. The connecting structure may be rigid, linearly adjustable, rotatable adjustable or both linearly and rotatable adjustable. The adjustable connecting structures allow for relative movement between the PMUs, while maintaining a load support surface(s) of the MPMSs.

BACKGROUND

The disclosure of the present patent application relates to wheeled systems, and particularly to multiple maneuvering systems for various applications.

2. Description of the Related Art

In general, wheeled systems or supporting and moving various types of loads are known. These systems, however, have many limitations. They are unable to reconfigure their structures to provide adjustable load support surfaces or additional lateral support. In addition, their steering systems are limited to single steering manipulators, thereby limiting their ability to navigate close areas such as aisles in stores, warehouses, factories, and other locations.

Thus, multiple maneuvering systems for various applications solving the aforementioned problems is desired.

SUMMARY

The multiple maneuvering systems for various applications includes several embodiments of wheeled, multiple maneuvering systems including multiple parallel maneuvering systems (MPMS). Each MPMS includes two or more parallel maneuvering units (PMUs) attached to one another by a connecting structure. Each PMU includes two or more powered or non-powered wheels, with the wheels being maintained parallel to one another by an independent steering mechanism. The steering mechanism may include gears, belt and pulley, chain and sprocket, or a rigid linkage. The connecting structure may be rigid, linearly adjustable, rotatable adjustable or both linearly and rotatable adjustable. The adjustable connecting structures allow for relative movement between the PMUs, while maintaining a load support surface(s) of the MPMSs. In a first embodiment of the MPMS, two independent PMUs are rigidly connected to one another with each PMU having an independent steering actuator. In a second embodiment, the two independent PMUs are connected to one another by a telescoping structure to allow adjustment of the distance between the PMUs. As in the first embodiment, each PMU has an independent steering actuator. By driving the wheels of the PMUs in opposite directions, the telescoping structure can be extended and retracted. As the telescoping structure is extended, four safety arms with wheels are extended laterally to provide additional stability for the MPMS, while the safety arms are retracted as the telescoping structure is retracted. In a third embodiment, four PMUs are connected to one another by hinged linkages to form a rectangular configuration. As in the first two embodiments, each PMU has an independent steering actuator, so that the PMUs can be moved relative to each other to form the desired configuration.

A control actuator in the form of a dual joystick controller can be used to control an MPMS with two independent PMUs. Two of the controllers may be used to control an MPMS with four independent PMUs. Other types of controllers, both joystick-types and others may be used controlling the steering and driving of the wheels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment of a multiple maneuvering system100is shown inFIG. 1in a compact configuration and inFIG. 2in a fully extended configuration. The multiple maneuvering system100is a multiple parallel maneuvering system (MPMS) and includes a first parallel maneuvering unit (PMU)102, and a second PMU104. Each of the PMUs102,104includes a top, load bearing panel106, left and right-side panels108and end panels110. Both of the PMUs102,104also includes left and right detachable safety leg assemblies. Each safety leg assembly includes a horizontal bar or arm112, with the proximate end of the arm112being rotatable attached to their respective PMU, as described in detail with respect toFIGS. 3-5. A vertical post114has an upper end attached to and extends downward from the distal end of the horizontal bar112, and a caster wheel116is rotatably attached to the lower end of the vertical post and contacts and rolls on the ground. As shown inFIG. 1, the MPMS100is in its compact configuration, with the safety leg assemblies retracted such that arms112are parallel to and in close proximity to the side panels108. In this configuration, the MPMS100is easily maneuvered in close quarters, such as aisles. As is shown inFIG. 2, the safety leg assemblies are extended such that arms112are perpendicular to the side panels108, such that the caster wheels116are extended far to the sides of the MPMS100, thereby providing additional lateral stability. To control the PMUs102,104an operator O uses a control actuator118, as described below with respect toFIGS. 18A-18B. While the control actuator118is shown connected to the MPMS100by an electrical cable120, it should be understood that the control actuator118and MPMS may be connected wirelessly, if desired.

InFIGS. 3-4, the panels106,108,110have been removed to show the inner details of the MPMS100. PMU102includes a chassis300with two wheels304(one shown) rotatably mounted to chassis300about steering axes and on rolling axles (not shown) mounted in hubs306. Similarly, PMU104includes a chassis302with two wheels304rotatably mounted to chassis302about steering axes and on rolling axles (not shown) mounted in hubs306. The steering and driving mechanisms for the PMUs102,104operate as those shown with respect to the PMUs described below and shown inFIGS. 15A-17B. A safety leg extension and retraction mechanism and a linearly adjustable structure is mounted on top of the chassis300,302. The linearly adjustable structure is a telescoping mechanism such that the chassis300and the chassis302can be extended or retracted from one another. The safety leg extension and retraction mechanism and the telescoping mechanism include a first frame308mounted on top of the chassis300and a second frame310mounted on top of the chassis302. The frames308,310are rotatably mounted to the top of their respective chassis300,302by horizontal pivot pins328to provide for relative vertical movement between the PMUs102,104when traveling over uneven surfaces.

The details of the telescoping mechanism are shown inFIGS. 3-5. The telescoping mechanism includes two longitudinally extending beams312that are connected to one another by a laterally extending beam314that extends between the approximate centers of the longitudinally extending beams312. The ends of the longitudinally extending beams312are slidingly received in channels316mounted on the sides of the frames308,310. The longitudinally extending beams312include through holes500in their side panels adjacent their ends. The longitudinally extending beams312also include through holes504in their side panels adjacent the laterally extending beam314. Locking mechanisms in the form of position locks400include pins (not shown) that extend through holes500to lock the telescoping mechanism in its extended position such that the PMUs102,104are maintained a maximum distance apart from one another. The position lock pins extend through holes504to lock the telescoping mechanism in its retracted position, such that the PMUs102,104are maintained a minimum distance apart from one another. By locking the telescoping mechanism, the stability of the MPMS100is increased in both its compact configuration and its fully extended configuration. To transition between configurations, the pins of the position locks400are retracted, thereby unlocking the telescoping mechanism.

In order to transition the MPMS100from its compact configuration (FIG. 3) to its extended configuration (FIG. 4), the operator O uses the control actuator118to steer and drive the wheels304of the PMU100away from the PMU200, or to steer and drive the wheels304of the PMU200away from the PMU100, or to simultaneously steer and drive the wheels304of the PMU100away from the PMU200while steering and driving the wheels304of the PMU200away from the PMU100. In order to transition the MPMS100from its extended configuration (FIG. 4) to its compact configuration (FIG. 3), the operator O uses the control actuator118to steer and drive the wheels304of the PMU100toward the PMU200, steer and drive the wheels304of the PMU200toward the PMU100, or simultaneously steer and drive the wheels304of the PMU100toward the PMU200while steering and driving the wheels304of the PMU200toward the PMU100.

The details of the safety legs and the safety leg extension and retraction mechanism are shown inFIGS. 3-5. The safety leg extension and retraction mechanism is operated by the telescoping mechanism to retract arms112in the compact configuration, and to extend the arms112in the extended configuration. The safety legs include vertical posts114that have upper ends attached to and extending downward from the distal ends of the arms112, and lower ends with caster wheels116mounted thereon for engaging and freely rolling on the ground. The arms112are rotatable attached to the outside corners of the frames308,310by a hinge assembly320. The arms112include integral first links318extending perpendicularly to the arms112and attached to the proximate ends of the arms112. Second links322have a proximate end rotatable attached to the distal ends of the first links318by pivots324, and distal ends rotatable attached to the ends of the longitudinally extending beams312by pivots326. Pivots324may be in the form of fasteners (nut/bolt, rivet, etc.) extending through holes in the distal ends of the first links318and holes in the proximate ends of the second links322. Pivots326may be in the form of fasteners (nut/bolt, rivet, etc.) extending through holes in the distal ends of the second links322and through holes502(FIG. 5) near the ends of the longitudinally extending beams312.

In operation, as the PMUs100,200move away from each other, the longitudinally extending beams312are pulled out of their respective channels316and pull the second links322and the attached distal ends of the first links318toward the center of the MPMS100, thereby rotating the arms112outwardly. Conversely, as the PMUs100,200move toward each other, the longitudinally extending beams312are pushed into their respective channels316and push the second links322and the attached distal ends of the first links318away from the center of the MPMS100, thereby rotating the arms112inwardly. The entire safety leg assembly is detachable from the MPMS100by removing the hinge pins from the hinge assemblies320and the pivots326, and then guiding the links318,322out through corner openings in the frames308,310.

A second embodiment of an MPMS600is shown inFIG. 6. This embodiment is useful for applications where relative linear motion between the PMUs is not required. A first PMU602is connected to a second PMU604by a rigid load bearing panel606. The PMUs602,604are attached to the load bearing panel606by horizontal pivot pins608to provide for relative vertical movement between the PMUs602,604when traveling over uneven surfaces. In this embodiment, PMU602includes three wheels610rotatably mounted to the chassis about steering axes and on rolling axles (not shown) mounted in hubs612. Similarly, PMU604includes a chassis with two wheels610rotatably mounted to the chassis about steering axes and on rolling axles (not shown) mounted in hubs (not shown). The steering and driving mechanisms for the PMUs602,604operate as those shown with respect to the PMUs described below and shown inFIGS. 15A-17B. One or more of the wheels610may include a motor614for driving the wheel about its rolling axis. It should be noted that while the PMU602is shown with three wheels and the PMU604is shown with two wheels, any number of wheels may be used in each PMU, and the various embodiments of the multiple maneuvering systems for various applications should not be deemed limited to any specific number of wheels.

A third embodiment of an MPMS700is shown inFIGS. 7-10. The MPMS700is shown in its compact configuration inFIG. 7. The MPMS700includes a first PMU702and a second PMU704. The first PMU702includes a chassis with two wheels718rotatably mounted to the chassis about steering axes and on rolling axles (not shown) mounted in hubs720. Similarly, PMU704includes a chassis with two wheels718(one shown) rotatably mounted to the chassis about steering axes and on rolling axles (not shown) mounted in hubs (not shown). The PMUs702,704both have recesses800(best seen inFIG. 10), sized and shaped to snugly receive a third PMU712and a fourth PMU714when the MPMS700is in its compact configuration. The third PMU712includes a chassis with two wheels718(one shown) rotatably mounted to the chassis about steering axes and on rolling axles (not shown) mounted in hubs720(not shown). Similarly, PMU714includes a chassis with two wheels718rotatably mounted to the chassis about steering axes and on rolling axles (not shown) mounted in hubs (one shown). The steering and driving mechanisms for the PMUs702,704,712,714operate as those shown with respect to the PMUs described below and shown inFIGS. 15A-17B. One or more of the wheels718may include a motor726for driving the wheel about its rolling axis. The PMUs702,704,712,714are connected to one another by a rotating and dual linear translation mechanism716.

The details of the rotation and dual linear translation (RDLT) mechanism716are best seen inFIGS. 8-11. The RDLT mechanism716includes a first linearly adjustable structure in the form of a telescoping mechanism as a connecting structure between PMUs702,704. The telescoping mechanism of the RDLT mechanism716is as described above with respect to the telescoping mechanism of the first embodiment, and as shown inFIGS. 3-5. As in the first embodiment the telescoping mechanism of the RDLT mechanism716includes two longitudinally extending beams706that are connected to one another by a laterally extending beam708that extends between the approximate centers of the longitudinally extending beams706. The ends of the longitudinally extending beams706are slidingly received in channels mounted within the PMUs702,704. Locking mechanisms in the form of position locks710lock the telescoping mechanism in its extended position or its retracted position. As in the first embodiment, to transition between configurations, the pins (not shown) of the position locks710are retracted, thereby unlocking the telescoping mechanism and allowing relative linear motion between PMUs702,704.

The RDLT mechanism716further includes a second linearly adjustable structure in the form of a scissor-type mechanism as a connecting structure between PMUs712,714. The scissor-type mechanism includes an upper cross member802and a lower cross member804. The upper cross member802and the lower cross member804are connected to one another by a vertical pivot at their centers. As best seen inFIG. 11, sliders1104are connected to both ends of the cross members802,804using angled brackets1106. The inside sidewall of the PMUs712,714include an upper1100and a lower1102track. The tracks1100,1102are U-shaped in cross section, for slidingly receiving the sliders1104therein. The sliders1104of the upper cross member802are slidingly received in the upper track1100, and the sliders1104of the lower cross member804are slidingly received in the lower1102track. Centering linkages1108include proximate ends rotatable attached to the inside sidewall of the PMUs712,714, and distal ends rotatable attached to the top surface of the cross members802,804. As the scissor-type mechanism extends, the sliders1104slide toward the center of the tracks1100,1102, and as the scissor-type mechanism retracts, the sliders1104slide toward the ends of the tracks1100,1102. The centering linkages1108maintain the sliders1104within the tracks1100,1102, by limiting the extent the sliders1104can travel toward the ends of the tracks1100,1102.

A rotation mechanism or bearing806connects the top center of the upper cross member802to the bottom center of the laterally extending beam708, to thereby provide relative rotational motion between PMUs702,704and PMUs712,714. A rotational brake808is mounted on the rotation bearing806to lock the bearing806and maintain the rotational position of the telescoping mechanism relative to the scissor-type mechanism. The construction of the rotation bearing806and rotational brake808may be similar to those shown and described in U.S. Pat. No. 11,015,664, issued to Cui et al. on May 25, 2021 and hereby incorporated by reference in its entirety.

To transition the MPMS700from its compact configuration (FIG. 7) to its transverse configuration (FIG. 10), an operator O first uses the control actuator118to simultaneously steer and drive the wheels718of the PMU702away from the PMU704while steering and driving the wheels718of the PMU704away from the PMU702, until the telescoping mechanism is in its maximum extended position as shown inFIG. 8. The operator O then uses the control actuator118to steer and drive the wheels718of the PMU712in a first direction, while steering and driving the wheels304of the PMU714in a second direction opposite to the first direction, to thereby rotate the PMUs712,714and the scissor-type mechanism relative to the PMUs702,704and the telescoping mechanism. The operator O may steer and drive the wheels718of the PMUs712,714, such that the first direction and second direction are diverging, thereby increasing the distance between PMUs712,714, while simultaneously rotating the PMUs712,714and the scissor-type mechanism relative to the PMUs702,704and the telescoping mechanism, resulting in a first intermediate configuration as shown inFIG. 8. Continuing the process, the distance between PMUs712,714, increases as does the relative rotation between the PMUs712,714and PMUs702,704, resulting in a second intermediate configuration as shown inFIG. 9. In this configuration, the distance between the PMUs712,714is at or near its maximum and the scissor-type mechanism is fully extended. The operator O then uses the control actuator118to steer and drive the wheels718of the PMU712in a first direction, while steering and driving the wheels304of the PMU714in a second direction opposite to the first direction, to thereby rotate the PMUs712,714relative to the PMUs702,704, resulting in the transverse configuration as shown inFIG. 10. It should be noted that many different steering motions may be used to transition the MPMS700from its various configurations, and the above-described procedure is just provided as an example. In addition, MPMS700is capable of many different configurations, only a few of which are shown inFIGS. 7-10.

A fourth embodiment of an MPMS1200is shown inFIG. 12, in an intermediate configuration. In the embodiment shown, the MPMS1200includes four PMUs1202,1204,1206,1208, although embodiments using two, three, five or more PMUs are contemplated. Each of the PMUs1202,1204,1206,1208includes a chassis1210with a steering actuator1216, and two wheels1218rotatably mounted to the chassis1210about steering axes and on rolling axles (not shown) mounted in hubs1220. One or both of the wheels1218of each PMU1202,1204,1206,1208may include a motor1230for driving the wheel1218about its rolling axis. The steering and driving mechanisms for the PMUs1202,1204,1206,1208operate as those shown with respect to the PMUs described below and shown inFIGS. 15A-17B. Each of the PMUs1202,1204,1206,1208further includes a load bearing panel1212, mounted on top of the chassis1210using a spherical joint or bearing1214. The spherical bearing1214allows the load bearing panel1212to rotate and tilt relative to the chassis1210.

The load bearing panels1212of each of the PMUs1202,1204,1206,1208are interconnected by a plurality of linkages1222. The linkages1222have a proximate end rotatably attached to tabs extending from corners of the load bearing panels1212, by a vertical pivot pin1224extending through holes in the tabs and in the proximate end of the linkages1222. The distal ends of the linkages1222are rotatably attached to the distal ends of adjacent linkages1222by vertical pivot pins1226extending through holes in the distal ends of the linkages1222, to form a complete circuit about the MPMS1200. As the vertical pivot pins1224,1226, allow for horizontal motion only, all of the load bearing panels1212and the linkages1222are substantially in the same plane. The spherical bearings1214allow the load bearing panels1212to tilt and rotate to compensate for uneven terrain that results in some of the PMUs1202,1204,1206,1208being at different elevations.

FIG. 13shows another example of a PMU1300. The PMU1300represents any of the PMUs1202,1204,1206,1208, and similarly includes a chassis1310with a steering actuator1316, and two wheels1318rotatably mounted to the chassis1310about steering axes and on rolling axles (not shown) mounted in hubs1320. One or both of the wheels1318may include a motor1330for driving the wheel1318about its rolling axis. The steering and driving mechanism for the PMU1300operates as those shown with respect to the PMUs described below and shown inFIGS. 15A-17B. The PMU1300further includes a load bearing panel1312, mounted on top of the chassis1310using a spherical joint or bearing. The spherical bearing includes a lower portion1314with an upper convex spherical surface that is received in a lower concave spherical surface (not shown) on an upper portion1324of the spherical bearing. The spherical bearing allows the load bearing panel1312to rotate and tilt relative to the chassis1310.FIG. 13also shows the details of the tabs1326of PMU1300. The tabs1326include through holes1328for receipt of the vertical pivot pins1224, as described above with respect to MPMS1200.

FIGS. 14A-17Billustrate a series of maneuvering and parallel maneuvering units (PMUs). Portions of the PMUs have been removed to show the details of the steering mechanisms of the PMUs.

FIGS. 14A-14Bshow the details of the steering mechanism of a single wheel maneuvering unit1400. The single wheel maneuvering unit1400includes a frame1402which may be part of the maneuvering unit's chassis. A driving shaft1404has a driving gear1406mounted on its top end. A driven shaft1408has a driven gear1410mounted on its top end. The driving shaft1404is driven by a steering actuator1416via a 90-degree gear box1412. The driven shaft1408extends through a steering yoke1414and is connected to one end of a horizontal plate1422. A downwardly extending bracket1424is attached to the opposite end of the horizontal plate1422. An axle (not shown) is mounted in a hub1420and a wheel1418it rotatable mounted on the axle. When the actuator1416is actuated, it drives the driving shaft1406and driving gear1406. The driving gear1406drives the driven gear1410and driven shaft1408, thereby turning the plate1422, the bracket1424and the wheel1418into the desired direction. The wheel1418may be driven by a motor1426, depending on the configuration of the MPMS in which the single wheel maneuvering unit1400is installed.

FIGS. 15A-Bshow the details of the steering mechanism of a first embodiment of a two-wheel PMU1500. The PMU1500includes a frame1502which may be part of the PMU's chassis. A driving shaft1504has a driving gear1506mounted on its top end. Two driven shafts1508have driven gears1510mounted on its top end. The driving shaft1504is driven by a steering actuator1516via a 90-degree gear box1512. The driven shafts1508extend through steering yokes1514and are connected to one end of horizontal plates1522. Downwardly extending brackets1524are attached to the opposite end of the horizontal plate1522. Axles (not shown) are mounted in hubs1520and wheels1518are rotatable mounted on the axles. When the actuator1516is actuated, it drives the driving shaft1506and driving gear1506. The driving gear1506drives the driven gears1510and driven shafts1508, thereby turning the plates1522, the bracket1524and the wheel1518into the desired direction. One or both of the wheels1518may be driven by a motor1526, depending on the configuration of the MPMS in which the PMU1500is installed. It should be noted that while the PMU1500is shown with two wheels1518, three or more wheels with corresponding hardware may be added, limited only by space constraints. Regardless of the number of wheels1518, the steering mechanism maintains all the wheels parallel to one another.

FIGS. 16A-Bshow the details of the steering mechanism of a second embodiment of a two-wheel PMU1600. The PMU1600includes a frame1602which may be part of the PMU's chassis. A driving shaft1404has a driving pulley or sprocket1606mounted on its top end. Two driven shafts1608have driven pulleys or sprockets1610mounted on their top end. A chain or belt1611extends around the driving pulley or sprocket1606and the driven pulleys or sprockets1610, for operationally connecting them. The driving shaft1604is driven by a steering actuator1616via a 90-degree gear box1612. The driven shafts1608extend through steering yokes1614and are connected to one end of horizontal plates1622. Downwardly extending brackets1624are attached to the opposite ends of the horizontal plates1622. Axles (not shown) are mounted in hubs1620and wheels1618are rotatable mounted on the axles. When the actuator1616is actuated, it drives the driving shaft1606and driving pulley or sprocket1606. The driving pulley or sprocket1606drives the chain or belt1611, the driven pulleys or sprockets1610, and driven shafts1608, thereby turning the plates1622, the bracket1624and the wheels1618into the desired direction. It should be noted that this embodiment covers both belt and pulley systems and chain and sprocket systems. One or both of the wheels1618may be driven by a motor1626, depending on the configuration of the MPMS in which the PMU1600is installed. It should be noted that while the PMU1600is shown with two wheels1618, three or more wheels with corresponding hardware may be added, limited only by space constraints. Regardless of the number of wheels1618, the steering mechanism maintains all the wheels parallel to one another.

FIGS. 17A-Bshow the details of the steering mechanism of a third embodiment of a two-wheel PMU1700. The PMU1700includes a frame1702which may be part of the PMU's chassis. A driving crank1704has a driving pin1706mounted on one end of its top surface. Two driven cranks1708have driven pins1710mounted on one end of their top surfaces. A rigid linkage1711includes three holes through which the driving pin1706and the driven pins1710extend, thereby operationally connecting the pins. The crank1704is driven by a steering actuator1716via a 90-degree gear box1712. The driven cranks1708have shafts (not shown) on their ends opposite the driven pins1710. The shafts extend through steering yokes1714and are connected to one end of horizontal plates1722. Downwardly extending brackets1724are attached to the opposite ends of the horizontal plates1722. Axles (not shown) are mounted in hubs1720and wheels1718are rotatable mounted on the axles. When the actuator1716is actuated, it drives the driving crank1706and the driving pin1706. The driving pin1706drives the rigid linkage1711, the driven pins1710, and their respective cranks1708, thereby turning the plates1722, the bracket1724and the wheels1718into the desired direction. One or both of the wheels1718may be driven by a motor1726, depending on the configuration of the MPMS in which the PMU1700is installed. It should be noted that while the PMU1700is shown with two wheels1718, three or more wheels with corresponding hardware may be added, limited only by space constraints. Regardless of the number of wheels1718, the steering mechanism maintains all the wheels parallel to one another.

FIGS. 18A-Bshow a control actuator in the form of a dual joystick controller1800. The dual joystick controller1800is configured to control an MPMS with two independent PMUs, such as MPMSs100,600. Two of the controllers1800may be used to control an MPMS with four independent PMUs, such as MPMSs700,1200. Other types of controllers, both joystick-types and others may be used controlling the steering and driving of the wheels.

The dual joystick controller1800includes two controllers1802,1804one for each PMU to be controlled. A housing1806includes an opening on its top surface, through which a first joystick1808and a second joystick1810extend. The joysticks1808,1810control the speed of the powered wheels of their respective PMU and are in the form of half cylinders such that they can rotate independently without interfering with one another. A first joystick angular transducer1828produces a signal indicative of the angular position of the first joystick1808, and a second joystick angular transducer (not shown) produces a signal indicative of the angular position of the second joystick1810. The signal is provided to electrical contacts1830. Pushing the joysticks1808,1810forward activates the wheels to move in a forward direction, while pulling the joysticks1808,1810backward activates the wheels to move in a reverse direction. The amount the joysticks1808,1810are pushed or pulled determines the speed of the wheels. For example, as shown inFIGS. 18A-B, joystick1808is shown in its maximum reverse position, while joystick1810is shown in its maximum forward position. The top of each joystick1808,1810includes an angular scale indicator1812for displaying the angle of inclination of the joystick. In addition, angular scale indicators1812may assist in aligning the joysticks, for driving all wheels of the MPMS at the same speed. When the joysticks1808,1810are directly upright or normal to the top of the housing1806, the wheels are not driven.

The joysticks1808,1810include horizontal cylindrical rods1814attached to, or integral with, and extending perpendicular to the rounded surfaces of the joysticks1808,1810. The horizontal rods1814have cylindrical steering sleeves1816rotatable mounted on them. The steering sleeves1816may include knurled or grooved surfaces1822on their inner ends, to provide greater friction for the operator. Sleeve angular transducers1824mounted on the distal ends of the horizontal rods1814produce signals indicative of the angular position of the steering sleeves1816relative to their respective horizontal rod1814. The signals are provided to electrical contacts1826. Each of the horizontal rods1814also includes a locking knob or raised surface1818on the top of its cylindrical surface and adjacent to their respective joystick1808,1810. Each of the steering sleeves1816include a locking recess1820in their interior surface adjacent to their inner ends. To steer the wheels of the respective PMUs, an operator twists the steering sleeves1816relative to the horizontal rods1814in a first direction for steering left and a second opposite direction for steering right. When the locking recess1820is aligned with the locking knob1818, the wheels of the associated PMU are steered in a longitudinal direction of the MPMS as described below with respect toFIGS. 20A-E. As shown, both steering sleeves1816are in their active mode and can control the steering of the wheels of their associated PMU. When an operator slides a steering sleeve1816inwardly, such that the locking knob1818is received in locking recess1820, the steering sleeve1816is in its inactive mode and cannot be rotated relative to its respective horizontal rods1814, and the wheels of their associated PMU are maintained in a longitudinal direction of the MPMS.

FIG. 19is a block diagram of an electrical control system for a two-PMU MPMS for various applications. In this example, a dual controller, such as the dual controller1800shown inFIGS. 18A-Band described above, is used to control two PMUs (PMU1and PMU2). The signal from the sleeve angular transducer1824of controller1802is sent to the steering manipulator controller of PMU1, while the signal from the sleeve angular transducer1824of controller1804is sent to the steering manipulator controller of PMU2. The steering manipulator controllers control their respective steering manipulator (for example, steering actuators1516,1616,1716) to steer the wheels of their respective PMU in the desired direction. The signal from the joystick angular transducer1828of controller1802is sent to the wheel actuator controller of PMU1, while the signal from the joystick angular transducer1828of controller1804is sent to the wheel actuator controller of PMU2. The wheel actuator controllers control their respective wheel actuators (for example, motors614,726,1526,1626,1726) to drive the wheels of their respective PMU in the desired direction and at the desired speed.

FIGS. 20A-20Eare diagrams showing various steering configurations of an MPMS2000having a three-wheel PMU2002and a two-wheel PMU2004connected by a connecting structure2006. In the diagrams, the wheels2008of PMU2002are steered at a first angle α1relative to the longitudinal axis of the MPMS2000, and the wheels2008of PMU2002are steered at a second angle α2relative to the longitudinal axis of the MPMS2000.

InFIG. 20A, α1=α2≠0°, such that all the wheels2008,2010are parallel to one another and steered in a diagonal direction relative to the longitudinal axis of the MPMS2000. Using the dual joystick controller1800, the cylindrical steering sleeves1816of both controllers1802,1804are active (the locking knobs1818are out of the locking recesses1820) and are rotated in the same direction and the same amount.

InFIG. 20B, α1=α2=0°, such that all the wheels2008,2010are parallel to one another and steered in a direction parallel to the longitudinal axis of the MPMS2000. Using the dual joystick controller1800, the cylindrical steering sleeves1816of both controllers1802,1804are rotated such that the locking knobs1818are aligned with the locking recesses1820. The steering sleeves1816may be slid outward and active (the locking knobs1818being out of the locking recesses1820) or slid inward and inactive (the locking knobs1818being within the locking recesses1820).

InFIG. 20C, α1=0°, α2≠0° such that the wheels2008are steered in a direction parallel to the longitudinal axis of the MPMS2000, and wheels2010are steered in a diagonal direction relative to the longitudinal axis of the MPMS2000. Using the dual joystick controller1800, the cylindrical steering sleeve1816of the controller1802is rotated such that its locking knob1818is aligned with the locking recesses1820. The cylindrical steering sleeve1816of the controller1804is rotated such that its locking knob1818is not aligned with the locking recesses1820. To operate MPMS2000in a conventional motor vehicle configuration, the steering sleeve1816of the controller1802is slid inward and inactive with its locking knob1818being within the locking recess1820, thereby maintaining wheels2008in a conventional stationary parallel rear wheel configuration. The cylindrical steering sleeve1816of the controller1804is slid outward and active, thereby allowing wheels2010to be steered in a conventional parallel steered front wheel configuration.

InFIG. 20D, α1≠α2≠0°, such that the wheels2008are steered in a first diagonal direction relative to the longitudinal axis of the MPMS2000and the wheels2010are steered in a second, different diagonal direction relative to the longitudinal axis of the MPMS2000(adjustable steering). In the specific relative position shown α1=−α2, such that wheels2008,2010are steered in the same angle relative to the longitudinal axis of the MPMS2000, but in opposite directions (four-wheel steering). Using the dual joystick controller1800, the cylindrical steering sleeves1816of both controllers1802,1804are active (the locking knobs1818are out of the locking recesses1820) and are rotated the same amount, but in opposite directions.

InFIG. 20E, α1=α2=90°, such that the wheels2008,2010are all steered in a direction perpendicular to the longitudinal axis of the MPMS2000(lateral steering). This position is particularly useful for parking a motor vehicle laterally between two obstacles. Using the dual joystick controller1800, the cylindrical steering sleeves1816of both controllers1802,1804are active (the locking knobs1818are out of the locking recesses1820) and are rotated to their maximum and in the same direction.