Motor Speed Sensor Diagnostics for Gear Rotation and Line Break Detection

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Solution Overview

Problem

The existing motor control apparatuses for industrial vehicles are costly due to the large number of sensors and signal lines required to determine if a gear is not rotating and if there is a signal line break.

Innovation Solution

A motor control apparatus that uses a detection unit to determine if a gear is not rotating and if there is a signal line break without additional sensors, by configuring the detection unit to detect abnormalities in signal line shorting or breaking based on signal levels and phase differences, and controls the motor operation accordingly, thereby reducing fabrication costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple sensors and signal lines are used to detect gear rotation status and signal line breaks, then detection reliability is improved, but fabrication cost increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidfabrication cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent makes the existing sensors Se1 and Se2 perform multiple functions: they detect both gear rotation status and signal line breaks. By analyzing signal levels and pulse wave patterns from these sensors, the system determines both rotation state and signal line integrity without adding extra sensors, thus reducing fabrication cost while maintaining detection reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own sensor signals to detect abnormalities. The detection unit analyzes the signals already being used for rotation detection to also identify signal line breaks, making the system self-diagnostic without requiring additional detection components

Inventive Principle:
Principle #25Self-service

2Measurement precision

If additional sensors are installed to determine gear rotation status and signal line breaks, then detection accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The existing sensors and signal lines are made multi-functional to perform both rotation detection and break detection, eliminating the need for additional sensors and reducing device complexity while maintaining detection accuracy

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The detection unit continuously monitors signal characteristics (signal levels and pulse wave patterns) from the sensors and uses this feedback to determine both rotation status and signal line integrity, achieving accurate detection without additional hardware

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3972116B1Motor control apparatus and industrial vehicle
Publication Date: 2023.11.08 TOYOTA INDUSTRIES CORP
  • EP3972116B1 patent drawingFigure 1
  • EP3972116B1 patent drawingFigure 2A~2C
  • EP3972116B1 patent drawingFigure 3A~3C

AI summary

A motor control apparatus for controlling the operation of a motor determines whether a gear connected to the shaft of the motor is rotating and whether there is a break in a signal line connected to a sensor for detecting the rotation speed of the gear, with an increase in fabrication cost suppressed. A motor control apparatus 1 includes a sensor Se1 that outputs a signal S1, a sensor Se2 that outputs a signal S2, and a detection unit 3 that detects that there is an abnormality of break in a signal line SL1 when the signal S1, which is acquired via the signal line SL1, is at a zero level, and detects that there is an abnormality of break in a signal line SL2 when the signal S2, which is acquired via the signal line SL2, is at the zero level.