Electrical power steering with two controllers and closed-loop integral action

Patent metadata

Field	Value
Publication number	US-10093348-B2
Application number	US-201715621163-A
Country	US
Kind code	B2
Filing date	Jun 13, 2017
Priority date	Jun 17, 2016
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

Technical solutions are described for a motor control system, such as one used in a steering system, the motor control system including multiple controllers. In an example, the motor control system includes a first arbitration module associated with a first controller, and a second arbitration module associated with a second controller. The first arbitration module generates a first arbitrated input signal based on a first input signal directed to the first controller, and a second input signal directed to the second controller. The second arbitration module generates a second arbitrated input signal based on the first input signal and the second input signal. The first controller generates a first control output using the first arbitrated input signal, and the second controller generates a second control output using the second arbitrated input signal.

First claim

What is claimed is:

1. A motor control system comprising:
a first controller;
a second controller;
a first arbitration module associated with the first controller, the first arbitration module configured to generate a first arbitrated input signal based on a first input signal directed to the first controller, and a second input signal directed to the second controller, the first arbitrated input signal used by the first controller to generate a first control output; and
a second arbitration module associated with the second controller, the second arbitration module configured to generate a second arbitrated input signal based on the first input signal directed to the first controller, and the second input signal directed to the second controller, the second arbitrated input signal used by the second controller to generate a second control output, wherein the first arbitration module computes the first arbitration signal by subtracting an offset from the first input signal, and the offset is computed based on a difference between the first input signal and the second input signal.

2. The motor control system of claim 1 , further comprising:
a first motor configured to generate a first torque in response to receiving the first control output; and
a second motor configured to generate a second torque in response to receiving the second control output.

3. The motor control system of claim 2 , wherein the first torque and the second torque are applied to a shaft being operated by the first motor and the second motor.

4. The motor control system of claim 1 , wherein the first input signal is a first command directed to the first controller and the second input signal is a second command directed to the second controller.

5. The motor control system of claim 1 , wherein the first input signal is a first measurement directed to the first controller, and the second input signal is a second measurement directed to the second controller.

6. The motor control system of claim 5 , wherein the first measurement is received from a first sensor that is part of a first closed-loop system of the first controller, and the second measurement is received from a second sensor that is part of a second closed-loop system of the second controller.

7. The motor control system of claim 5 , wherein the first measurement is measured by a sensor at a first time-point and the second measurement is measured by the sensor at a second time-point.

8. The motor control system of claim 1 , wherein the first input signal is an integral state of the first controller and the second input signal is an integral state of the second controller.

9. The motor control system of claim 1 , wherein the first arbitration module is further configured to minimize a value of the offset for differences that change at frequencies above a predetermined threshold by scaling the offset based on the frequency of the offset, prior to subtracting the offset from the first input signal.

10. The motor control system of claim 1 , wherein the second arbitration module subtracts an offset from the second input signal, the offset computed based on a difference between the second input signal and the first input signal.

11. A method for operating a motor control system that includes two or more controllers, the method comprising:
computing, by a first arbitration module associated with a first controller, a first arbitrated input signal based on a first input signal directed to the first controller, and a second input signal directed to a second controller;
generating, by the first controller, a first control output using the first arbitrated input signal;
computing, by a second arbitration module associated with the second controller, a second arbitrated input signal based on the first input signal directed to the first controller, and the second input signal directed to the second controller, wherein the first arbitration signal is computed by subtracting an offset from the first input signal, and the offset is computed based on a difference between the first input signal and the second input signal; and
generating, by the second controller, a second control output using the second arbitrated input signal.

12. The method of claim 11 , wherein the first input signal is a first command directed to the first controller and the second input signal is a second command directed to the second controller.

13. The method of claim 11 , wherein the first input signal is a first measurement directed to the first controller, and the second input signal is a second measurement directed to the second controller, and wherein the first measurement is received from a first sensor that is part of a first closed-loop system of the first controller, and the second measurement is received from a second sensor that is part of a second closed-loop system of the second controller.

14. The method of claim 11 , wherein the first input signal is a first measurement directed to the first controller, and the second input signal is a second measurement directed to the second controller, and wherein the first measurement is measured by a sensor at a first time-point and the second measurement is measured by the sensor at a second time-point.

15. The method of claim 11 , wherein the first input signal is an integral state of the first controller and the second input signal is an integral state of the second controller.

16. The method of claim 11 , wherein:
computing the second arbitrated signal comprises subtracting a second offset from the second input signal, the second offset computed by subtracting the first input signal from the second input signal.

17. An electric power steering system comprising:
a first motor configured to generate a first assist torque;
a second motor configured to generate a second assist torque;
a first controller to generate a first control output for the first motor using a closed-loop control loop to generate the first assist torque;
a second controller to generate a second control output for the second motor using a closed-loop control loop to generate the second assist torque;
a first arbitration module associated with the first controller, the first arbitration module configured to generate a first arbitrated input signal based on a first input signal directed to the first controller, and a second input signal directed to the second controller, the first arbitrated input signal used by the first controller to generate the first control output; and
a second arbitration module associated with the second controller, the second arbitration module configured to generate a second arbitrated input signal based on the first input signal directed to the first controller, and the second input signal directed to the second controller, the second arbitrated input signal used by the second controller to generate a second control output, wherein computing the first arbitrated signal comprises subtracting a first offset from the first input signal, the first offset being computed by subtracting the second input signal from the first input signal.

18. The electric power steering system of claim 17 , wherein:
the first input signal comprises at least one of a first input command to the first controller, and a measurement received by the first controller, and
the second input signal comprises at least one of a second input command to the second controller, and a measurement received by the second controller.

19. The electric power steering system of claim 17 , wherein the first input signal is an integral

Assignees

• Steering Solutions Ip Holding

Inventors

• Hales Michael K

Classifications

• B62D5/0463 Primary

  calculating assisting torque from the motor based on driver input · CPC title

• H02P6/04

  Arrangements for controlling or regulating the speed or torque of more than one motor (H02P6/10 takes precedence) · CPC title

• H02P5/74 Primary

  controlling two or more AC dynamo-electric motors (H02P5/46, H02P5/60 take precedence) · CPC title

• B62D5/0421

  Electric motor acting on or near steering gear · CPC title

• H02P5/00

  Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors (H02P6/04, H02P8/40 take precedence) · CPC title