Crawl operations for four-wheel steering vehicles

Patent metadata

Field	Value
Publication number	US-11993262-B2
Application number	US-202017039224-A
Country	US
Kind code	B2
Filing date	Sep 30, 2020
Priority date	Sep 30, 2020
Publication date	May 28, 2024
Grant date	May 28, 2024

Abstract

Crawl operations for four-wheel steering vehicles are described herein. An example vehicle described herein includes four wheels, a front steering actuator to turn the front wheels, a rear steering actuator to turn the rear wheels, a front drive motor to drive the front wheels, and a rear drive motor to drive the rear wheels. The vehicle also includes an electronic control unit (ECU) to activate the front steering actuator to turn the front wheels in a first direction, activate the rear steering actuator to turn the rear wheels in a second direction opposite the first direction such that the front wheels and the rear wheels are turned in opposite directions, activate the front drive motor to drive the front wheels in a reverse direction, and activate the rear drive motor to drive the rear wheels in a forward direction while the front wheels are driven in the reverse direction.

First claim

What is claimed is:

1. A vehicle comprising:
a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel;
a front steering actuator to turn the left and right front wheels;
a rear steering actuator to turn the left and right rear wheels;
a front drive motor to drive the left and right front wheels;
a rear drive motor to drive the left and right rear wheels; and
an electronic control unit (ECU) programmed to:
activate the front steering actuator to turn the left and right front wheels in a first direction;
activate the rear steering actuator to turn the left and right rear wheels in a second direction opposite the first direction such that the left and right front wheels and the left and right rear wheels are turned in opposite directions; and
while the left and right front wheels are turned in the first direction and the left and right rear wheels are turned in the second direction, activate the front drive motor to drive the left and right front wheels in a reverse direction and activate the rear drive motor to drive the left and right rear wheels in a forward direction such that the left and right front wheels are driven in the reverse direction while the left and right rear wheels are driven in the forward direction.

2. The vehicle of claim 1 , further including a yaw sensor, the ECU programmed to modulate power to the front and rear drive motors based on measurements from the yaw sensor to limit rotation of the vehicle.

3. The vehicle of claim 1 , further including a rear differential lock and a front differential lock, the ECU programmed to activate the front and rear differential locks prior to activating the front and rear drive motors.

4. The vehicle of claim 1 , wherein the ECU is programmed to activate the front and rear steering actuators and activate the front and rear drive motors in response to a request for a left crawl operation or right crawl operation from a driver.

5. The vehicle of claim 4 , wherein:
when the request is for the left crawl operation, the ECU is programmed to activate the front steering actuator to turn the left and right front wheels to the right and activate the rear steering actuator to turn the left and right rear wheels to the left; and
when the request is for the right crawl operation, the ECU is programmed to activate the front steering actuator to turn the left and right front wheels to the left and activate the rear steering actuator to turn the left and right rear wheels to the right.

6. The vehicle of claim 4 , wherein the ECU is programmed to deactivate the left crawl operation or the right crawl operation in response to a cancel command from the driver.

7. The vehicle of claim 4 , wherein the ECU is programmed to deactivate the left crawl operation or the right crawl operation in response to determining the vehicle has gained traction.

8. The vehicle of claim 7 , further including one or more torque sensors associated with one or more of the wheels, the ECU programmed to determine the vehicle has gained traction based on measurements from the one or more torque sensors.

9. A non-transitory machine readable medium comprising instructions that, when executed, cause an electronic control unit (ECU) of a vehicle to:
activate a front steering actuator of the vehicle to turn front wheels of the vehicle in a first direction;
activate a rear steering actuator of the vehicle to turn rear wheels of the vehicle in a second direction opposite the first direction such that the front wheels and the rear wheels are turned in opposite directions;
activate a front drive motor to drive the front wheels in a reverse direction; and
activate a rear drive motor to drive the rear wheels in a forward direction while the front drive motor is activated and driving the front wheels in the reverse direction and while the left and right front wheels are turned in the first direction and the left and right rear wheels are turned in the second direction.

10. The non-transitory machine readable medium of claim 9 , wherein the instructions, when executed, cause the ECU to modulate power to the front and rear drive motors based on measurements from a yaw sensor to limit rotation of the vehicle.

11. The non-transitory machine readable medium of claim 9 , wherein the instructions, when executed, cause the ECU to, prior to activating the front and rear drive motors, activate front and rear differential locks.

12. The non-transitory machine readable medium of claim 9 , wherein the instructions, when executed, cause the ECU to, prior to activating the front and rear steering actuators and the front and rear drive motors, determine whether the vehicle is stopped.

13. A vehicle comprising:
a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel;
a left front steering actuator to turn the left front wheel;
a right front steering actuator to turn the right front wheel;
a left rear steering actuator to turn the left rear wheel;
a right rear steering actuator to turn the right rear wheel;
a front drive motor to drive the left and right front wheels;
a rear drive motor to drive the left and right rear wheels; and
an electronic control unit (ECU) programmed to:
activate the left front steering actuator and the left rear steering actuator to turn the left front wheel and the left rear wheel, respectively, in a first direction;
activate the right front steering actuator and the right rear steering actuator to turn the right front wheel and the right rear wheel, respectively, in a second direction while the left front wheel and the left rear wheel are turned in the first direction; and
while the left front wheel and the left rear wheel are turned in the first direction and the right front wheel and the right rear wheel are turned in the second direction, activate the front drive motor and the rear drive motor to drive the left and right front wheels and the left and right rear wheels, respectively, in a same direction.

14. The vehicle of claim 13 , further including a yaw sensor, the ECU programmed to modulate power to the front and rear drive motors based on measurements from the yaw sensor to limit rotation of the vehicle.

15. The vehicle of claim 13 , further including a rear differential lock and a front differential lock, the ECU programmed to activate the front and rear differential locks prior to activating the front and rear drive motors.

16. The vehicle of claim 13 , wherein the ECU is programmed to activate the left front steering actuator, the right front steering actuator, the left rear steering actuator, the right rear steering actuator, the front drive motor, and the rear drive motor in response to a request for a forward crawl operation or a reverse crawl operation from a driver.

17. The vehicle of claim 16 , wherein, when the request is for the forward crawl operation, the ECU is programmed to:
activate the left front steering actuator and the left rear steering actuator to turn the left front wheel and the left rear wheel, respectively, to the right;
activate the right front steering actuator and the right rear steering actuator to turn the right front wheel and the right rear wheel, respectively, to the left; and
activate the front and rear drive motors to drive the left and right front wheels and the left and right rear wheels, respectively, in a forward direction.

18. The vehicle of claim 17 , wherein, when the request is for the reverse crawl operation, the ECU is programmed to:
activate the left front steering actuator and the left rear steering actuato

Assignees

• Ford Global Tech Llc

Inventors

• Collins Patrick Gordon

Classifications

• B60W30/18063 Primary

  Creeping · CPC title

• B60K1/02

  comprising more than one electric motor · CPC title

• B60K17/348

  having differential means for driving one set of wheels, e.g. the front, at one speed and the other set, e.g. the rear, at a different speed (B60K17/346 takes precedence) · CPC title

• B60K17/356

  having fluid or electric motor, for driving one or more wheels · CPC title

• B60K17/358

  all driven wheels being steerable · CPC title