Control loop for transportation vehicles

• US 5,791,425 A
• Filed: 06/07/1995
• Issued: 08/11/1998
• Est. Priority Date: 02/24/1993
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Ambrogi, Robert R., Duggan, Robert J., Kamen, Dean L., Dastous, Susan D., Heinzmann, Richard K., Key, Brian R.
• Primary Examiner(s): BOEHLER, ANNE MARIE M
• Application Number:
  US08/482,616
• Time in Patent Office: 1,161 Days
• Field of Search: 180/7.1, 180/8.2, 180/8.3, 180/8.5, 180/8.6, 180/65.1, 180/65.8, 180/907, 180/118, 180/6.48, 180/6.5, 180/6.54, 180/41, 180/21, 280/5.2, 280/5.26, 280/5.28, 280/5.32, 280/6.1, 280/205, 280/DIG. 10, 901/1, 364/176, 701/4, 701/29, 701/33, 701/116, 701/124
• US Class Current: 180/7.1
• CPC Class Codes: A61G 2203/14 Joysticks
• CPC Class Codes: A61G 2203/20 Displays or monitors
• CPC Class Codes: A61G 5/04 motor-driven A61G5/06 takes precedence; motor-operated rests A61G5/12; for vehicles with handlebars, equipped with three or more wheels B62K5/003, B62K5/023
• CPC Class Codes: A61G 5/061 for climbing stairs
• CPC Class Codes: A61G 5/065 with three or more wheels mounted on a rotary cross member, e.g. spiders or spoked wheels with small wheels at the end of the spokes
• CPC Class Codes: A61G 5/068 with extensible supports pushing upwards, e.g. telescopic legs
• CPC Class Codes: A61G 5/1059 adjusting the height of the seat
• CPC Class Codes: A61G 5/107 positioning the whole seat forward or rearward
• CPC Class Codes: A61G 5/1075 tilting the whole seat backwards tilting forwards for standing-up or sitting-down aids A61G5/14
• CPC Class Codes: A61G 5/125 for arms
• CPC Class Codes: A61G 5/128 for feet
• CPC Class Codes: A61G 5/14 Standing-up or sitting-down aids
• CPC Class Codes: B60K 7/00 Disposition of motor in, or adjacent to, traction wheel roller-skate driving mechanisms A63C17/12
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 2200/16 Single-axle vehicles
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/22 Yaw angle
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/461 : Speed
• CPC Class Codes: B60L 2240/463 : Torque
• CPC Class Codes: B60L 2240/545 : Temperature
• CPC Class Codes: B60L 2240/547 : Voltage
• CPC Class Codes: B60L 2240/549 : Current
• CPC Class Codes: B60L 2240/642 : Slope of road
• CPC Class Codes: B60L 2240/80 : Time limits
• CPC Class Codes: B60L 2250/10 : by alarm
• CPC Class Codes: B60L 2250/16 : by display
• CPC Class Codes: B60L 2250/24 : by lever actuation
• CPC Class Codes: B60L 2260/28 : Four wheel or all wheel drive
• CPC Class Codes: B60L 2260/34 : Stabilising upright position of vehicles, e.g. of single axle vehicles
• CPC Class Codes: B60L 50/52 : characterised by DC-motors
• CPC Class Codes: B60L 58/21 : having the same nominal voltage
• CPC Class Codes: B62D 57/00 : Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track sledges B62B; motor sledges B62M
• CPC Class Codes: B62K 11/007 : Automatic balancing machines with single main ground engaging wheel or coaxial wheels supporting a rider
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 180/907 : Motorized wheelchairs

Abstract

There is provided, in a preferred embodiment, a transportation vehicle for transporting an individual over ground having a surface that may be irregular. This embodiment has a support for supporting the subject. A ground-contacting module, movably attached to the support, serves to suspend the subject in the support over the surface. The orientation of the ground-contacting module defines fore-aft and lateral planes intersecting one another at a vertical. The support and the ground-contacting module are components of an assembly. A motorized drive, mounted to the assembly and coupled to the ground-contacting module, causes locomotion of the assembly and the subject therewith over the surface. Finally, the embodiment has a control loop, in which the motorized drive is included, for dynamically enhancing stability in the fore-aft plane by operation of the motorized drive in collection with the ground-contacting module. The ground contacting module may be realized as a pair of ground-contacting members, laterally disposed with respect to one another. The ground-contacting members may be wheels. Alternatively, each ground-contacting member may include a cluster of wheels. In another embodiment, each ground-contacting member includes a pair of axially adjacent and rotatably mounted arcuate element pairs. Related methods are also provided.

Claims

1. A vehicle, for transporting a human subject over a surface that may be irregular, the vehicle comprising:

(a) a support for supporting the subject;

(b) a ground-contacting module, movably attached to the support, for suspending the subject in the support over the surface, the orientation of the ground-contacting module defining fore-aft and lateral planes;

the support and the ground-contacting module being components of an assembly;

(c) a motorized drive, mounted to the assembly for causing locomotion of the assembly and the subject over the surface; and

(d) a control loop, in which the motorized drive is included, for dynamically maintaining stability in the fore-aft plane by operation of the motorized drive so that the net torque experienced by the assembly about a point of contact with the surface, taking into account torques caused by gravity as well as by all other external forces and by the motorized drive, causes a desired acceleration,

wherein the control loop performs the following steps on a cyclical basis;

(1) reading state variable inputs and inputs provided by the subject;

(2) checking for safety of operation based upon comparison of the state variables with specified ranges of values; and

(3) performing calculations for controlling the motorized drive based on the subject-provided inputs and the state variable inputs.

2. A vehicle, for transporting a human subject over a surface that may be irregular, the vehicle comprising:

(a) a support for supporting the subject;

(b) a ground-contacting module, movably attached to the support, for suspending the subject in the support over the surface, the orientation of the ground-contacting module defining fore-aft and lateral planes;

the support and the ground-contacting module being components of an assembly;

(c) a motorized drive, mounted to the assembly for causing locomotion of the assembly and the subject over the surface; and

(d) a control loop, in which the motorized drive is included, for dynamically maintaining stability in the fore-aft plane by operation of the motorized drive so that the net torque experienced by the assembly about the point of contact with the surface, taking into account torques caused by gravity as well as by all other external forces and by the motorized drive, causes a desired acceleration, the control loop having a speed limiting controller for limiting the speed of the vehicle to a desired speed threshold below the maximum speed of which the vehicle is currently capable, so that fore-aft stability of the vehicle may continue to be maintained by the control loop.

3. A vehicle according to claim 2, wherein the control loop includes an inclinometer to provide an output indicative of the pitch of the vehicle, and the speed, limiting controller means includes means for adding a pitch modification to the inclinometer output whenever the vehicle speed exceeds the speed threshold.

4. A vehicle according to claim 3, wherein the pitch modification is a function of the amount by which the speed exceeds the threshold.

5. A vehicle according to claim 4, wherein the speed limiting controller includes speed capability means for determining on a real time basis the maximum speed of which the vehicle is currently capable.

6. A vehicle according to claim 5, wherein the vehicle has an electrical power source to power the motorized drive and the speed capability means has an input for receiving a signal indicative of the output currently provided by the power source to the motorized drive.

7. A vehicle, for transporting a human subject over ground having a surface that may be irregular, the vehicle comprising:

(a) a support for supporting the subject;

(b) a pair of ground-contacting members laterally disposed with respect to one another and movably attached to the support, for suspending the subject in the support over the surface, the orientation of the ground-contacting members defining fore-aft and lateral planes, wherein each ground-contacting member includes a cluster of wheels for contacting the ground, each cluster being rotatably mounted on and motor-driven about a laterally disposed central axis, and each of the wheels in each cluster being rotatably mounted about an axis parallel to the central axis, the wheels being capable of being motor-driven independently of the cluster;

the support and the ground-contacting members being components of an assembly;

(c) a motorized drive, mounted to the assembly, for causing locomotion of the assembly and the subject over the surface; and

(d) a control loop, in which the motorized drive is included, for dynamically enhancing stability in the fore-aft plane by operation of the motorized drive, the control loop including cluster control means for controlling the angular orientation of each cluster about the central axis and wheel control means for controlling separately, as to the wheels of each cluster, the rotation of wheels in contact with the ground, wherein;

in a first condition, the wheel control means is in a slave mode in which the wheels are driven as a function of the rotation of the clusters; and

the cluster control means is in a lean mode in which the clusters are driven in such a manner as to tend to maintain balance of the vehicle in the fore-aft plane while the wheels are in the slave mode, so as to permit the vehicle to ascend or descend stairs or other surface features;

in a second condition, the wheel control means is in a balance mode in which the wheels of each cluster in contact with the ground are driven in such a manner as to maintain balance of the vehicle in the fore-aft plane while the cluster control means is in a fixed mode in which the clusters are not rotating; and

the control loop has transition means for controlling the transition in at least one direction between the first and second conditions.

8. A vehicle according to claim 7, wherein the transition means includes:

lean-to-balance transition means for causing a transition in the cluster control means from lean mode to a fixed mode in which the clusters are not rotating, and in the wheel control means from slave mode to balance mode.

9. A vehicle according to claim 8, wherein the control loop includes an inclinometer to provide an output indicative of the pitch of the vehicle, and the lean-to-balance transition means includes means for adding a pitch modification to the inclinometer output until a first desired angular orientation of the clusters has been achieved.

10. A vehicle according to claim 9, wherein the lean-to-balance transition means includes means, operative when the first desired angular orientation has been achieved, both for causing the wheel control means to enter the balance mode and for smoothly continuing angular rotation of the clusters until a second desired angular orientation has been achieved, whereupon the cluster control means enters the fixed mode.

11. A vehicle according to claim 7, wherein the transition means includes:

balance-to-lean transition means for causing a transition in the cluster control means from fixed mode to lean mode and in the wheel control means from balance mode to slave mode.

12. A vehicle according to claim 11, wherein the feedback loop includes an inclinometer to provide an output indicative of the pitch of the vehicle, and the balance-to-lean transition means includes means for causing gradual rotation of the clusters to a first destination angular position while simultaneously adding a pitch modification to the inclinometer output to maintain the vehicle'"'"'s center of gravity over the balancing wheels.

13. A vehicle according to claim 12, wherein the lean-to-balance transition means includes means, operative when the first destination angular orientation of the clusters has been achieved, both for causing the cluster control means to enter lean mode and the wheel control means to enter slave mode and for smoothly removing the pitch modification.

14. A vehicle, for transporting a human subject over a surface that may be irregular, the vehicle comprising:

(a) a support for supporting the subject;

(b) a ground-contacting module, movably attached to the support, for suspending the subject in the support over the surface, the orientation of the ground-contacting module defining fore-aft and lateral planes;

the support and the ground-contacting module being components of an assembly;

(c) a motorized drive, mounted to the assembly for causing locomotion of the assembly and the subject over the surface; and

(d) a control loop, in which the motorized drive is included, for dynamically maintaining stability in the fore-aft plane by operation of the motorized drive so that the net torque experienced by the assembly about a point of contact with the surface, taking into account torques caused by gravity as well as by all other external forces and by the motorized drive, causes a desired acceleration, the control loop including a plurality of microprocessors, each microprocessor assigned to a separate set of tasks associated with vehicle locomotion and control, in communication with one another over a signal bus.