# US 10,374,541 B2 · Motor control system and method for detecting abnormality in resolver/digital converter

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- Number: US 10,374,541 B2
- Document ID: US10374541B2
- Status: Granted
- Kind: B2
- Application number: 15/939,599
- Filed: 2018-03-29
- Published: 2018-11-29
- Granted: 2019-08-06
- Earliest claimed: 2017-05-25
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Kazuya Yamamoto; Yu Sasaki
- Web page: https://patentgrep.com/patent/US10374541B2

## CPC

- H02P 27/045: {whereby the speed is regulated by measuring the motor speed and comparing it with a given physical value}
- H02P 29/0241: {the fault being an overvoltage}
- H03M 1/1076: {Detection or location of converter hardware failure, e.g. power supply failure, open or short circuit}
- H03M 1/645: {for position encoding, e.g. using resolvers or synchros (H03M1/485 takes precedence)}
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C)

## Abstract

A motor control system includes a motor, a resolver configured to detect a rotation angle of the motor, a resolver/digital converter configured to convert an analog angle signal output from the resolver into a digital angle signal, and a motor control unit configured to control the motor based on the digital angle signal output from the resolver/digital converter and determine, when an integrated value obtained by integrating the digital angle signal at a predetermined time interval is not within a threshold range, that the resolver/digital converter is abnormal. The motor control unit increases the time interval for the integration when a rotation speed of the motor decreases and decreases the time interval for the integration when the rotation speed of the motor increases.

## Claims

### Claim 1

A motor control system comprising:
a motor;
a resolver configured to detect a rotation angle of the motor;
a resolver/digital converter configured to convert an analog angle signal output from the resolver into a digital angle signal; and
a motor control unit configured to control the motor based on the digital angle signal output from the resolver/digital converter and determine, when an integrated value obtained by integrating the digital angle signal at a predetermined time interval is out of a threshold range, that the resolver/digital converter is abnormal, wherein
the motor control unit increases the time interval when a rotation speed of the motor decreases and decreases the time interval when the rotation speed of the motor increases.

### Claim 2 (depends on 1)

The motor control system according to claim 1, wherein the time interval is successively increased as the rotation speed of the motor decreases, and the time interval is successively decreased as the rotation speed of the motor increases.

### Claim 3 (depends on 1)

The motor control system according to claim 1, wherein the motor control unit obtains the rotation speed of the motor based on a drive current of the motor.

### Claim 4

A method for detecting an abnormality in a resolver/digital converter, comprising:
converting, by a resolver/digital converter, a rotation angle of a motor detected by a resolve into a digital angle signal and integrating the obtained digital angle signal at a predetermined time interval; and
determining, when the integrated value of the digital angle signal is out of a threshold range, that the resolver/digital converter is abnormal, wherein
the time interval is increased when a rotation speed of the motor decreases, and is decreased when the rotation speed of the motor increases.