Motion sensing diagnostics for permanent magnet dc motor drive

Patent metadata

Field	Value
Publication number	US-2025392241-A1
Application number	US-202418749862-A
Country	US
Kind code	A1
Filing date	Jun 21, 2024
Priority date	Jun 21, 2024
Publication date	Dec 25, 2025
Grant date	—

Abstract

Technical solutions are described for diagnosing a sensor error in an actuator having a permanent magnet DC (PMDC) motor, including: measuring, by a position sensor, a measured position of the PMDC motor; determining, based on the measured position, an estimated motor velocity; measuring, by a current sensor, a measured current in the PMDC motor; determining, based on the measured current in the PMDC motor, a voltage command for the PMDC motor; determining, based on the measured current and the voltage command, and using a motor velocity observer, an observed velocity of the PMDC motor; determining a difference velocity as a difference between the estimated motor velocity and the observed velocity; determining, based on the difference velocity, the sensor error; and performing an action in response to determining the sensor error.

First claim

What is claimed is:

1 . A method of diagnosing a sensor error in an actuator having a permanent magnet DC (PMDC) motor, comprising:
measuring, by a position sensor, a measured position of the PMDC motor; determining, based on the measured position, an estimated motor velocity; measuring, by a current sensor, a measured current in the PMDC motor; determining, based on the measured current in the PMDC motor, a voltage command for the PMDC motor; determining, based on the measured current and the voltage command, and using a motor velocity observer, an observed velocity of the PMDC motor; determining a difference velocity as a difference between the estimated motor velocity and the observed velocity; determining, based on the difference velocity, the sensor error; and performing an action in response to determining the sensor error.

2 . The method of claim 1 , wherein determining the sensor error further includes comparing the difference velocity to a velocity error threshold, and wherein the method further includes adjusting the velocity error threshold based on an operating condition of the actuator.

3 . The method of claim 2 , wherein adjusting the velocity error threshold includes adjusting the velocity error threshold further based on the observed velocity.

4 . The method of claim 3 , wherein adjusting the velocity error threshold includes increasing the velocity error threshold based on the observed velocity being less than a low velocity threshold value.

5 . The method of claim 1 , wherein the PMDC motor includes a brushed PMDC motor having brushes for transmitting DC current from a stationary terminal to a rotor winding.

6 . The method of claim 1 , wherein the PMDC motor is an actuator motor configured to control a position of a handwheel of a steering system in a vehicle.

7 . The method of claim 1 , wherein performing the action in response to determining the sensor error includes at least one of: generating a diagnostic trouble code and notifying an operator of the sensor error.

8 . The method of claim 1 , wherein performing the action in response to determining the sensor error includes performing an action to mitigate an effect of the sensor error.

9 . A motor control system, comprising:
a position sensor configured to measure a measured position of a PMDC motor; a current sensor configured to measure a measured current in the PMDC motor; and a controller configured to:
determine, based on the measured position, an estimated motor velocity;
determine, based on the measured current in the PMDC motor, a voltage command for the PMDC motor;
determine, based on the measured current and the voltage command, and using a motor velocity observer, an observed velocity of the PMDC motor;
determine a difference velocity as a difference between the estimated motor velocity and the observed velocity;
determine, based on the difference velocity, a sensor error; and
perform an action in response to determining the sensor error.

10 . The motor control system of claim 9 , wherein the controller is further configured to:
compare the difference velocity to a velocity error threshold, and adjust the velocity error threshold based on an operating condition of the PMDC motor.

11 . The motor control system of claim 10 , wherein the controller is configured to adjust the velocity error threshold further based on the observed velocity.

12 . The motor control system of claim 11 , wherein the controller is configured to increase the velocity error threshold based on the observed velocity being less than a low velocity threshold value.

13 . The motor control system of claim 9 , wherein the PMDC motor includes a brushed PMDC motor having brushes for transmitting DC current from a stationary terminal to a rotor winding.

14 . The motor control system of claim 9 , wherein the PMDC motor is an actuator motor configured to control a position of a handwheel of a steering system in a vehicle.

15 . The motor control system of claim 9 , wherein performing the action in response to determining the sensor error includes the controller performing at least one of: generating a diagnostic trouble code and notifying an operator of the sensor error.

16 . The motor control system of claim 9 , wherein performing the action in response to determining the sensor error includes the controller performing an action to mitigate an effect of the sensor error.

17 . A motor control system, comprising:
a position sensor configured to measure a measured position of a PMDC motor; a current sensor configured to measure a measured current in the PMDC motor; a processor; and a memory that includes instructions that, when executed by the processor, cause the processor to:
determine, based on the measured position, an estimated motor velocity;
determine, based on the measured current in the PMDC motor, a voltage command for the PMDC motor;
determine, based on the measured current and the voltage command, and using a motor velocity observer, an observed velocity of the PMDC motor;
determine a difference velocity as a difference between the estimated motor velocity and the observed velocity;
determine, based on the difference velocity, a sensor error; and
perform an action in response to determining the sensor error.

18 . The motor control system of claim 17 , wherein the instructions further cause the processor to:
compare the difference velocity to a velocity error threshold, and adjust the velocity error threshold based on an operating condition of the PMDC motor.

19 . The motor control system of claim 18 , wherein the instructions further cause the processor to adjust the velocity error threshold further based on the observed velocity.

20 . The motor control system of claim 19 , wherein the instructions further cause the processor to increase the velocity error threshold based on the observed velocity being less than a low velocity threshold value.

Assignees

• Steering Solutions Ip Holding

Inventors

• Pramod Prerit
• Mehta Siddharth
• Pandya Vidit V
• Narayanaswamy Chethan
• Kirk Joshua D

Classifications

• H02P6/006

  Controlling linear motors · CPC title

• H02P21/18 Primary

  Estimation of position or speed · CPC title