Plausibility checking of field-oriented control

Patent metadata

Field	Value
Publication number	US-10668946-B2
Application number	US-201615748213-A
Country	US
Kind code	B2
Filing date	Jul 21, 2016
Priority date	Jul 30, 2015
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

The description relates to a method for controlling a servo drive of a steering system of a vehicle, comprising the step of: failure of the feedback comprising the step of: monitoring the control of the servo drive.

First claim

The invention claimed is:

1. A method for controlling a servo drive of a steering system of a vehicle, the method comprising:
operating the servo drive using feedback control based on feedback signals;
continuing to operate the servo drive using feedback-less control in response to a failure of the at least one of the feedback signals; and
during the continued operation of the servo drive using the feedback-less control:
measuring a first phase current of the servo drive;
calculating a second phase current of the servo drive;
determining a rotor angular position of the servo drive;
monitoring the continued operation of the servo drive using the feedback-less control, based on the measured first phase current, the calculated second phase current, and the determined rotor angular position, to detect a fault; and
turning off the servo drive in response to detecting the fault,
wherein the measured first phase current and the calculated second phase current do not influence the continued operation of the servo drive using the feedback-less control.

2. The method as claimed in claim 1 , the monitoring further comprising:
monitoring the continued operation of the servo drive using the feedback-less control one of continuously and periodically.

3. The method as claimed in claim 1 further comprising:
measuring only one phase current of the servo drive.

4. The method as claimed in claim 1 further comprising:
calculating an actual state of the servo drive based on the measured first phase current, the calculated second phase current, and the determined rotor angular position.

5. The method as claimed in claim 4 further comprising:
comparing the actual state with a target state of the servo drive.

6. The method as claimed in claim 1 , wherein the servo drive is a synchronous machine.

7. A steering system of a vehicle, the steering system comprising:
a servo drive; and
a control system configured to:
operate the servo drive using feedback control based on feedback signals;
continue to operate the servo drive using feedback-less control in response to a failure of the at least one of the feedback signals;
during the continued operation of the servo drive using the feedback-less control:
measure a first phase current of the servo drive;
calculate a second phase current of the servo drive;
determine a rotor angular position of the servo drive;
monitor the continued operation of the servo drive using the feedback-less control, based on the measured first phase current, the calculated second phase current, and the determined rotor angular position, to detect a fault; and
turn off the servo drive in response to detecting the fault,
wherein the measured first phase current and the calculated second phase current do not influence the continued operation of the servo drive using the feedback-less control.

Assignees

• Bosch Gmbh Robert Automotive Steering

Inventors

• Burkhardt Thomas
• Elzmann Malte

Classifications

• B62D5/0484 Primary

  for reaction to failures, e.g. limp home · CPC title

• B62D5/0487

  detecting motor faults (B62D5/0496 takes precedence) · CPC title