Independent control of vehicle wheels

• US 10,759,416 B1
• Filed: 10/18/2017
• Issued: 09/01/2020
• Est. Priority Date: 10/18/2017
• Status: Active Grant

• Current Assignee: Zoox Inc. (Amazon.com, Inc.)
• Original Assignee: Zoox Inc. (Amazon.com, Inc.)
• Inventors: Funke, Joseph, Edren, Johannes, Javidan, Ali
• Primary Examiner(s): Butler, Rodney A
• Application Number:
  US15/787,334
• Time in Patent Office: 1,049 Days
• CPC Class Codes: B60T 2201/10 Automatic or semi-automatic parking aid systems
• CPC Class Codes: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• CPC Class Codes: B60T 2210/12 Friction
• CPC Class Codes: B60T 2260/02 Active Steering, Steer-by-Wire
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B60T 8/17554 specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention road vehicle drive control systems for roll-over prevention otherwise than by controlling a particular sub-unit B60W30/04
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2030/043 about the roll axis
• CPC Class Codes: B60W 2520/18 Roll
• CPC Class Codes: B60W 2720/14 Yaw
• CPC Class Codes: B60W 2720/28 Wheel speed
• CPC Class Codes: B60W 2720/30 Wheel torque
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 30/04 related to roll-over prevention
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60W 40/068 Road friction coefficient
• CPC Class Codes: B60W 40/109 Lateral acceleration
• CPC Class Codes: B62D 17/00 : Means on vehicles for adjusting camber, castor, or toe-in
• CPC Class Codes: B62D 6/00 : Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00
• CPC Class Codes: B62D 6/002 : computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 6/04 : responsive only to forces disturbing the intended course of the vehicle, e.g. forces acting transversely to the direction of vehicle travel
• CPC Class Codes: B62D 7/06 : for individually-pivoted wheels, e.g. on king-pins
• CPC Class Codes: B62D 7/159 : characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition

Abstract

An over actuated system capable of controlling wheel parameters, such as speed (e.g., by torque and braking), steering angles, caster angles, camber angles, and toe angles, of wheels in an associated vehicle. The system may determine the associated vehicle is in a rollover state and adjust wheel parameters to prevent vehicle rollover. Additionally, the system may determine a driving state and dynamically adjust wheel parameters to optimize driving, including, for example, cornering and parking. Such a system may also dynamically detect wheel misalignment and provide alignment and/or corrective driving solutions. Further, by utilizing degenerate solutions for driving, the system may also estimate tire-surface parameterization data for various road surfaces and make such estimates available for other vehicles via a network.

Claims

1. A wheel control system configured to facilitate control of a vehicle having a longitudinal axis extending along a line between a first end of the vehicle and a second end of the vehicle opposite the first end of the vehicle, the wheel control system comprising:

a first steering assembly configured to be coupled proximate to the first end of the vehicle and control one or more parameters of first wheels coupled proximate to the first end of the vehicle;

a second steering assembly configured to be coupled proximate to the second end of the vehicle and control one or more parameters of second wheels coupled proximate to the second end of the vehicle; and

a wheel controller configured to;

receive a signal indicative of a vehicle maneuver, the signal indicative of a vehicle maneuver comprising a signal indicative of a speed of the vehicle; and

control operation of the first steering assembly to the one or more parameters of the first wheels to pivot the first wheels at first steering angles in a first direction relative to the longitudinal axis of the vehicle and the second steering assembly to control the one or more parameters of the second wheels to pivot the second wheels at second steering angles in a second direction relative to the longitudinal axis of the vehicle according to a first mode based at least in part on the signal indicative of the speed being less than a threshold speed and according to a second mode when the signal indicative of the speed being greater than the threshold speed, the first and second steering angles having opposite signs,

wherein the one or more parameters of the first and second steering assemblies comprise a steering angle and one or more of a caster angle, a camber angle, a toe angle, or a wheel speed.

2. The wheel control system of claim 1, wherein the signal indicative of the vehicle maneuver corresponds to the vehicle following a trajectory having a curvature greater than zero and a speed greater than zero.

3. The wheel control system of claim 1, wherein the wheel controller is configured to control operation of the first steering assembly and second steering assembly according to transition from operation according to the first mode to operation according to the second mode when the signal indicative of the speed of the vehicle indicates the speed of the vehicle is increasing.

4. The wheel control system of claim 1, wherein controlling the first steering assembly and the second steering assembly according to the first mode comprises causing the first steering assembly to adjust one or more of the caster angle, camber angle, or toe angle.

5. The wheel control system of claim 1, wherein the signal indicative of a vehicle maneuver comprises a signal indicative of initiating parallel parking into a parking space, wherein when the vehicle approaches the parking space in a first travel direction, the wheel controller is configured to control operation of the first steering assembly and the second steering assembly to cause the vehicle to park in the parking space without the vehicle traveling in a second travel direction opposite the first travel direction.

6. The wheel control system of claim 5, wherein the wheel controller is configured to:

control operation of the first steering assembly to provide steering angles of the first wheels that direct the first wheels toward a parking space and into the parking space while controlling operation of the second steering assembly to provide steering angles of the second wheels that direct the second wheels away from the parking space; and

maneuvering the vehicle into the parking space.

7. The wheel control system of claim 6, wherein the wheel controller is configured to thereafter control operation of the first steering assembly to provide steering angles of the first wheels that direct the first wheels in a direction at least one of along a longitudinal axis of the parking space or toward a distal longitudinal border of the parking space and into the parking space, while controlling operation of the second steering assembly to provide steering angles of the second wheels that direct the second wheels toward the distal longitudinal border of the parking space and into the parking space.

15. The wheel control system of claim 1, wherein the signal indicative of the vehicle maneuver further comprises a signal indicative of an instability associated with the vehicle and a signal indicative of the steering angle of the vehicle.

8. A wheel control system configured to facilitate control of a wheel, the wheel control system comprising:

a steering assembly configured to control steering angles of the wheel, the wheel coupled proximate to a first end of a vehicle; and

a wheel controller configured to receive a signal indicative of a state of the vehicle, and to control operation a first steering assembly to pivot first wheels at first steering angles in a first direction relative to the longitudinal axis of the vehicle and a second steering assembly to pivot second wheels at second steering angles in a second direction relative to the longitudinal axis of the vehicle, the first and second steering angles having the same sign, the signal indicative of the state of the vehicle comprising a signal indicating a signal indicative of speed of the vehicle.

9. The wheel control system of claim 8, wherein:

the signal indicative of a state of the vehicle comprises one or more of;

a signal indicative of a steering angle of the vehicle;

and

the wheel controller is configured to control, based at least in part on the one or more signals indicative of the state of the vehicle, one or more wheel parameters of the first wheels by controlling operation of one or more of;

a camber adjustment assembly configured to control a camber angle of the wheel;

a caster adjustment assembly to configured to control a caster angle of the wheel;

or

a toe adjustment assembly configured to control a toe angle of the wheel.

10. The wheel control system of claim 8, wherein:

the adjustment assembly is a caster adjustment assembly and the caster adjustment assembly is configured to cause the wheel to have a positive caster angle.

14. The wheel control system of claim 8, wherein the adjustment assembly is a chamber adjustment assembly and the chamber adjustment assembly is configured to cause the wheel to have a negative chamber angle.

16. The wheel control system of claim 8, wherein:

the signal indicative of a state of the vehicle comprises a signal indicative of an instability associated with the vehicle; and

the wheel controller is configured to control, based at least in part on the signal indicative of the state of the vehicle, one or more wheel parameters of the first wheels by controlling operation of one or more of;

a camber adjustment assembly configured to control a camber angle of the wheel;

a caster adjustment assembly to configured to control a caster angle of the wheel;

or

a toe adjustment assembly configured to control a toe angle of the wheel.

17. The wheel control system of claim 8, wherein the signal indicative of a state of the vehicle further comprises a signal indicative of initiating parallel parking into a parking space, wherein the wheel controller is configured to control operation of the first steering assembly and the second steering assembly to cause the vehicle to park in the parking space.

11. A method for adjusting one or more wheel parameters, the method comprising:

receiving, at a wheel control system, a signal indicative of a state of a vehicle, the signal indicative of the state of the vehicle comprises a signal indicative of the vehicle turning;

causing, based at least in part on the signal, the wheel control system to control operation of a camber adjustment assembly to increase amounts of negative camber angle of first wheels based at least in part on the signal indicative of the vehicle turning, and

wherein the state of the vehicle comprises one or more of a speed of the vehicle, a direction of the vehicle, a steering angle of the vehicle, or an instability of the vehicle.

12. The method of claim 11, wherein:

the wheel is configured to be coupled to a first end of the vehicle,

the signal indicative of the state of the vehicle comprises a signal indicative that the vehicle is traveling in a forward travel direction, such that the first end of the vehicle is a front end of the vehicle, and

the one or more wheel parameters comprise a toe angle,

the method further comprising configuring a wheel controller of the wheel control system to control operation of a toe adjustment assembly to cause the wheel to have toe-in based at least in part on the signal indicative that the vehicle is travelling in the forward travel direction.

13. The method of claim 11, wherein the one or more wheel parameters comprise a toe angle, the method further comprising configuring the wheel controller to control operation of a toe adjustment assembly to adjust the toe angle based at least in part on the signal indicative that the vehicle is turning.

18. The method of claim 11, wherein in response to receiving the signal indicative of the vehicle turning, transitioning the vehicle from a first mode of operation to a second mode of operation.

19. The method of claim 11, wherein the wheel controller is further configured to control operations of a caster adjustment assembly and a toe angle adjustment assembly.

20. The method of claim 11, wherein the signal indicative of the state of the vehicle further comprises a signal indicative that the vehicle is travelling above a threshold speed.

21. The method of claim 20, wherein controlling operations of the camber adjustment assembly is based at least in part on the vehicle travelling above the threshold speed.