Systems and methods for providing redundancy to electronic speed control systems

Patent metadata

Field	Value
Publication number	US-10901414-B2
Application number	US-201916358125-A
Country	US
Kind code	B2
Filing date	Mar 19, 2019
Priority date	Sep 20, 2016
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A method for driving an electric motor includes providing two controllers for driving the electric motor. The two controllers use different control methods to drive the electric motor. The method further includes selecting a first controller of the controllers as a primary controller to drive the electric motor and a second controller of the controllers as a secondary controller, monitoring a control of the electric motor, and switching the control of the electric motor from the primary controller to the secondary controller if an error condition is detected in the control of the electric motor.

First claim

What is claimed is:

1. A method for driving an electric motor, comprising:
providing two controllers, including a first controller and a second controller, for driving the electric motor, the two controllers using different control methods to drive the electric motor, the first controller being configured to drive the electric motor with a drive signal having a sinusoidal waveform, and the second controller being configured to drive the electric motor with the drive signal having a trapezoidal waveform;
monitoring a control of the electric motor, the control of the electric motor being performed by a primary controller or a secondary controller;
selecting, in response to a characteristic parameter of the electrical motor exceeding a threshold value or falling outside of a range, the second controller as the primary controller to drive the electric motor and the first controller as the secondary controller;
selecting, in response to the characteristic parameter of the electrical motor not exceeding the threshold value and not falling outside of the range, the first controller as the primary controller to drive the electric motor and the second controller as the secondary controller; and
switching the control of the electric motor from the primary controller to the secondary controller if an error condition is detected in the control of the electric motor.

2. The method of claim 1 , wherein:
monitoring the control comprises monitoring a status of a communication between the two controllers and the electric motor or between the two controllers and a third controller, and the error condition includes a hardware error causing a disruption in the communication or a failure in components of the primary controller; or
the error condition includes a software error including an inconsistency in at least one characteristic of the control of the electric motor.

3. The method of claim 1 ,
wherein monitoring the control comprises measuring at least one characteristic of the control of the electric motor;
the method further comprising:
detecting the error condition based on the measurement of the at least one characteristic.

4. The method of claim 3 , wherein measuring the at least one characteristic comprises measuring the at least one characteristic by both of the controllers in two measurements, and detecting the error condition comprises comparing the two measurements.

5. The method of claim 3 wherein the at least one characteristic includes at least one of a speed of the electric motor or an electrical angle of the electric motor.

6. The method of claim 1 , wherein:
a third controller monitors the at least one characteristic of the control of the electric motor and selects one of the two controllers as the primary controller.

7. The method of claim 1 , wherein:
a third controller switches the control of the electric motor.

8. The method of claim 1 , wherein the two controllers are configured to communicate with each other directly or via a third controller.

9. The method of claim 1 , wherein the two controllers are configured to communicate with a third controller.

10. A system for driving an electric motor, comprising:
two controllers, including a first controller and a second controller, for driving the electric motor, wherein the two controllers use different control methods to drive the electric motor, the first controller is configured to drive the electric motor with a drive signal having a sinusoidal waveform, the second controller is configured to drive the electric motor with the drive signal having a trapezoidal waveform, and the system is configured to:
monitor a control of the electric motor, the control of the electric motor being performed by a primary controller or a secondary controller;

select, in response to a characteristic parameter of the electrical motor exceeding a threshold value or falling outside of a range, the second controller as the primary controller to drive the electric motor and the first controller as the secondary controller;
select, in response to the characteristic parameter of the electrical motor not exceeding the threshold value and not falling outside of the range, the first controller as the primary controller to drive the electric motor and the second controller as the secondary controller; and switch the control of the electric motor from the primary controller to the secondary controller if an error condition is detected in the control of the electric motor.

11. The system of claim 10 , wherein:
the two controllers are further configured to monitor a status of a communication between the two controllers and the electric motor or between the two controllers and a third controller, and the error condition includes a hardware error causing a disruption in the communication or a failure in components of the primary controller; or
the error condition includes a software error including an inconsistency in at least one characteristic of the control of the electric motor.

12. The system of claim 10 , wherein the two controllers are further configured to:
measure at least one characteristic of the control of the electric motor; and
detect the error condition based on the measurement of the at least one characteristic.

13. The system of claim 12 , wherein the two controllers are further configured to:
measure the at least one characteristic in two measurements, respectively; and
detect the error condition by comparing the two measurements.

14. The system of claim 12 , wherein the at least one characteristic includes at least one of a speed of the electric motor or an electrical angle of the electric motor.

15. The system of claim 10 , wherein:
a third controller monitors the at least one characteristic of the control of the electric motor and selects which one of the two controllers as the primary controller.

16. The system of claim 10 , wherein:
a third controller switches the control of the electric motor.

17. The system of claim 10 , wherein the two controllers are configured to communicate with each other directly or via a third controller.

18. The system of claim 10 , wherein the two controllers are configured to communicate with a third controller.

19. The method of claim 1 , wherein the first controller and the second controller use different commutations in the drive signal.

20. The method of claim 1 , wherein the characteristic parameter of the electrical motor includes one or more of: an internal resistance of the electric motor, an inductance of the electric motor, a magnetic flux of the electric motor, and a temperature of the electric motor.

Assignees

• Sz Dji Technology Co Ltd

Inventors

• Lan Qiu
• Zhou Changxing

Classifications

• B64U50/19

  using electrically powered motors · CPC title

• G05D1/0072

  to counteract a motor failure · CPC title

• G05D1/0077 Primary

  using redundant signals or controls · CPC title

• H02P27/085

  wherein the PWM mode is adapted on the running conditions of the motor, e.g. the switching frequency · CPC title

• H02P7/00

  Arrangements for regulating or controlling the speed or torque of electric DC motors · CPC title