Reducer-Mounted Sensor Control for Accurate Arm State Detection

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Solution Overview

Problem

Existing drive devices with a reducer between the motor and the arm face challenges in accurately detecting temperature changes of the arm using a temperature sensor attached to the motor.

Innovation Solution

A control unit that controls the motor based on detection values from sensors mounted on the reducer, allowing for accurate detection and control of the arm's state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a temperature sensor is attached to the motor to detect temperature changes, then the motor control can be performed, but the detection accuracy of the arm's temperature change deteriorates due to the reducer being positioned between the motor and the arm

Engineering Contradiction:

Improvetemperature detection accuracyVSAvoidarm state detection accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a sensor as an intermediary device mounted on the reducer to detect the arm's state directly. This sensor acts as a mediator between the arm and the control system, providing accurate detection of the arm's temperature and other states without being influenced by the motor's temperature or the reducer's mechanical transmission characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent shifts the detection location from the motor (one dimension of the system) to the reducer (another dimension closer to the arm). This spatial repositioning of the sensor allows direct measurement of the arm's state, bypassing the limitations of motor-based detection and providing more relevant data for control purposes.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Speed

If a reducer is positioned between the motor and the arm to decelerate rotation, then the motor can operate at higher speeds, but the direct detection of the arm's state becomes difficult

Engineering Contradiction:

Improvemotor rotational speedVSAvoidarm state detection difficulty

Core Design Contradiction:

SpeedVSDifficulty of detecting and measuring

Solution Approach 1:

The sensor mounted on the reducer serves as an intermediary that directly measures the arm's state. This intermediary device overcomes the obstacle created by the reducer's position, enabling accurate detection despite the mechanical deceleration stage between the motor and the arm.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces indirect mechanical detection (through the motor and reducer transmission) with direct sensor-based detection. This substitution of detection methodology eliminates the difficulties associated with mechanical transmission and provides accurate electrical signals for control purposes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4506114A1Control unit, drive device, and control method

Publication Date: 2025.02.12 NIDEC DRIVE TECH CORP

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AI summary

A drive device (100) includes a motor (103), a reducer (1), and a target object. The reducer (1) decelerates rotational motion output from the motor (103). The target object is operated by rotational motion output from the reducer (1). A control unit (2) controls the motor (103) based on a detection value of a sensor (50) mounted on the reducer (1).