Steering and traction applications for determining a steering control attribute and a traction control attribute

1. A method comprising:

iteratively performing:

a) receiving, by a steering application executing on a vehicle control module:

a steering control input from a vehicle steering device to control a steered wheel of a vehicle;

a measured value of a steering control attribute related to the steered wheel; and

a measured value of a traction control attribute related to a traction wheel of the vehicle;

b) based on the steering control input, the measured value of the steering control attribute and the measured value of the traction control attribute, determining, by the steering application:

a first setpoint value of the steering control attribute related to the steered wheel for use in controlling a steering motor associated with the steered wheel;

a target steering angle of the steered wheel of the vehicle;

c) receiving, by a traction application executing on the vehicle control module of the vehicle:

a traction speed control input to control the traction wheel of the vehicle, and

the target steering angle, from the steering application;

d) based on the traction speed control input and the target steering angle, determining, by the traction application:

a second setpoint value of the traction control attribute.

2. The method of claim 1 , comprising:

calculating, by the steering application, a wheel angle command based on the steering control input.

3. The method of claim 2 , comprising:

determining, by the steering application, a traction speed limit based on the wheel angle command; and

determining, by the steering application, whether the measured value of the traction control attribute related to the traction wheel of the vehicle is less than the traction speed limit.

4. The method of claim 3 , comprising:

when the measured value of the traction control attribute related to the traction wheel of the vehicle is less than the traction speed limit:

setting the first set point value to equal the wheel angle command; and

setting the target steering angle to equal:

a) the wheel angle command, when the wheel angle command is greater than the measured value of the steering control attribute, and

b) the measured value of the steering control attribute, when the wheel angle command is less than or equal to the measured value of the steering control attribute.

5. The method of claim 2 , comprising:

determining, by the steering application, a traction speed limit based on the wheel angle command;

determining, by the steering application, a wheel angle limit based on the measured value of the traction control attribute related to the traction wheel; and

determining, by the steering application, whether the measured value of the traction control attribute related to the traction wheel of the vehicle is more than or equal to the traction speed limit.

6. The method of claim 5 , comprising:

when the measured value of the traction control attribute related to the traction wheel of the vehicle is more than or equal to the traction speed limit:

setting the target steering angle to equal the wheel angle command; and

setting the first set point value to equal one of:

a) the wheel angle limit, when the wheel angle limit is between the measured value of the steering control attribute and the wheel angle command;

b) the measured value of the steering control attribute, when the wheel angle limit is:

i) not between the measured value of the steering control attribute and the wheel angle command; and

ii) closer to the measured value of the steering control attribute than to the wheel angle command, and

c) the wheel angle command, when the wheel angle limit is:

i) not between the measured value of the steering control attribute and the wheel angle command; and

ii) closer to the wheel angle command than to the measured value of the steering control attribute.

7. The method of claim 1 , wherein the steering control attribute comprises a steered wheel angle.

8. The method of claim 1 , wherein the steering control attribute comprises an angular velocity of a steering motor coupled with the steered wheel of the vehicle.

9. The method of claim 1 , wherein the traction control attribute comprises one of:

a linear speed of the vehicle;

a speed of the traction wheel; and

a speed of a traction motor coupled with the traction wheel of the vehicle.

10. A system on a vehicle comprising:

a controller comprising:

a first input configured to receive a steering control input from a steering device on the vehicle to control a steered wheel of the vehicle;

a second input configured to receive a measured value of a steering control attribute related to the steered wheel;

a third input configured to receive a measured value of a traction control attribute related to a traction wheel of the vehicle;

a fourth input configured to receive a traction speed control input to control the traction wheel of the vehicle;

a memory coupled with the controller and storing code executable by the controller,

the executable code comprising a steering application and a traction application configured to iteratively perform:

a) based on the steering control input, the measured value of the steering control attribute and the measured value of the traction control attribute, determining, by the steering application:

a first setpoint value of a steering control attribute related to the steered wheel of the vehicle for use in controlling a steering motor associated with the steered wheel;

a target steering angle of the steered wheel of the vehicle;

b) receiving, by the traction application:

a traction speed control input to control the traction wheel of the vehicle, and

the target steering angle, from the steering application; and

c) based on the traction speed control input and the target steering angle, determining, by the traction application:

a second setpoint value of the traction control attribute.

11. The system of claim 10 , wherein the steering application is further configured to calculate a wheel angle command based on the steering control input.

12. The system of claim 11 , wherein the steering application is further configured to:

determine a traction speed limit based on the wheel angle command; and

determine whether the measured value of the traction control attribute related to the traction wheel of the vehicle is less than the traction speed limit.

13. The system of claim 12 , wherein the steering application is further configured to:

when the measured value of the traction control attribute related to the traction wheel of the vehicle is less than the traction speed limit:

set the first set point value to equal the wheel angle command; and

set the target steering angle to equal:

a) the wheel angle command, when the wheel angle command is greater than the measured value of the steering control attribute, and

b) the measured value of the steering control attribute, when the wheel angle command is less than or equal to the measured value of the steering control attribute.

14. The system of claim 11 , wherein the steering application is further configured to:

determine a traction speed limit based on the wheel angle command;

determine a wheel angle limit based on the measured value of the traction control attribute related to the traction wheel; and

determine whether the measured value of the traction control attribute related to the traction wheel of the vehicle is more than or equal to the traction speed limit.

15. The system of claim 14 , wherein the steering application is further configured to:

when the measured value of the traction control attribute related to the traction wheel of the vehicle is more than or equal to the traction speed limit:

set the target steering angle to equal the wheel angle command; and

set the first set point value to equal one of:

a) the wheel angle limit, when the wheel angle limit is between the measured value of the steering control attribute and the wheel angle command;

b) the measured value of the steering control attribute, when the wheel angle limit is:

i) not between the measured value of the steering control attribute and the wheel angle command; and

ii) closer to the measured value of the steering control attribute than to the wheel angle command, and

c) the wheel angle command, when the wheel angle limit is:

i) not between the measured value of the steering control attribute and the wheel angle command; and

ii) closer to the wheel angle command than to the measured value of the steering control attribute.

16. The system of claim 10 , wherein the steering control attribute comprises a steered wheel angle.

17. The system of claim 10 , wherein the steering control attribute comprises an angular velocity of a steering motor coupled with the steered wheel of the vehicle.

18. The system of claim 10 , wherein the traction control attribute comprises one of:

a linear speed of the vehicle;

a speed of the traction wheel; and

a speed of a traction motor coupled with the traction wheel of the vehicle.

19. The method of claim 1 , wherein the traction control attribute comprises a torque value.

20. The system of claim 10 , wherein the traction control attribute comprises a torque value.