Motor Control Circuit Pseudo-Abnormality Signal Generation

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Solution Overview

Problem

Existing motor control devices for steering systems, such as electric power steering (EPS), face challenges in accurately detecting abnormalities in communication results, leading to potential errors in calculating steering angles due to undetected abnormalities in the control circuit or communication interface, which can result in unreliable operation.

Innovation Solution

Incorporating a pseudo abnormality generating unit that sets detection results to be abnormal based on pseudo abnormal signals, allowing the control device to detect and correct for abnormalities in the communication interface and main circuit, ensuring accurate information is used for calculations, thereby enhancing the reliability of the control circuit and motor control device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a detection result communication unit is added to detect abnormalities in the main circuit, then the reliability of abnormality detection is improved, but the device complexity increases due to additional components and communication interfaces

Engineering Contradiction:
Improveabnormality detection reliabilityVSAvoidcontrol circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control circuit performs self-diagnosis by generating pseudo-abnormality signals and verifying whether the detection result communication unit correctly transmits abnormality information. This self-testing mechanism enables the system to autonomously detect communication abnormalities without requiring external testing equipment, thereby improving reliability while avoiding the complexity of additional external diagnostic systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system establishes a feedback loop where the control device sends pseudo-abnormality signals to the detection result communication unit, which then transmits detection results back to the control device. The control device compares the expected abnormality signal with the actual detection result to identify communication failures. This feedback mechanism ensures reliable detection while maintaining a manageable device architecture through iterative verification.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If pseudo abnormality generating unit is implemented to test communication interface, then the measurement precision of communication abnormality detection is improved, but the device complexity increases due to additional testing functionality

Engineering Contradiction:
Improvecommunication abnormality detection precisionVSAvoidcontrol circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control device generates pseudo-abnormality signals before actual operation to pre-test the detection result communication unit. By performing this preliminary testing, the system verifies the communication interface functionality in advance, ensuring high detection precision when actual abnormalities occur. This preliminary action approach allows the system to maintain precise detection capabilities while integrating the testing function within existing control circuit components.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3789270B1Control circuit and motor control device
Publication Date: 2022.08.10 JTEKT CORP
  • EP3789270B1 patent drawingFigure 1
  • EP3789270B1 patent drawingFigure 2
  • EP3789270B1 patent drawingFigure 3

AI summary

A control circuit connected to a control device configured to control a motor connected to a rotation shaft that is convertible into a turning angle of a turning wheel, the control circuit includes a main circuit configured to calculates a rotation number indicating a rotational state of the rotation shaft based on a detection signal from a rotation angle sensor configured to detect a rotation angle of the motor as a relative angle, a detection result communication unit configured to detect whether or not there is an abnormality in the main circuit and output a detection result to the control device, and a pseudo abnormality generating unit configured to set the detection result to be abnormal based on a pseudo abnormal signal from the control device.