Gearbox Actuator Feedback Control With One Output Angle Sensor
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Solution Overview
Problem
The use of a large number of detection units in actuator devices increases weight, volume, and cost, while also reducing positioning accuracy due to backlash and vibration in mechanical elements like gears.
Innovation Solution
An actuator device with a motor, gearbox, angle sensor on the output shaft, and feedback circuit that uses internal motor information to estimate and correct the rotation angle, reducing the need for sensors on the motor shaft and minimizing backlash-induced noise and errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple detection units are provided in the actuator device to improve position control accuracy, then measurement precision is improved, but weight, volume, and cost increase
Solution Approach 1:
The patent combines multiple detection functions into a single angle sensor on the output shaft. The feedback circuit integrates motor position estimation (from internal information) and output shaft position detection (from angle sensor) into a unified control system, eliminating the need for separate detection units on the motor shaft and output shaft, thereby reducing weight while maintaining position control accuracy
Solution Approach 2:
The single angle sensor on the output shaft serves multiple functions: detecting output shaft rotation angle, providing feedback for position control, and enabling backlash compensation. This multi-functional approach replaces what would traditionally require multiple specialized sensors, reducing overall system weight and complexity
2Measurement precision
If multiple detection units are provided in the actuator device to improve position control accuracy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent merges the functions of multiple detection units into a single angle sensor combined with a sophisticated feedback circuit. The feedback circuit processes both motor internal information and angle sensor output to achieve accurate position control, reducing the number of physical sensors from multiple to one while maintaining control accuracy through intelligent signal processing
Solution Approach 2:
The feedback circuit acts as an intermediary that processes information from the single angle sensor and motor internal information to generate accurate position control signals. This intermediary processing compensates for the reduced number of sensors, maintaining measurement precision while simplifying the overall device structure
3Measurement precision
If detection units are provided on both motor shaft and output shaft to compensate for backlash, then measurement precision is improved, but weight and cost increase
Solution Approach 1:
The patent implements a feedback mechanism where the single angle sensor on the output shaft provides position information that is combined with motor internal information in the feedback circuit. This feedback loop enables backlash compensation by comparing expected motor position with actual output shaft position, eliminating the need for separate detection units on both shafts while maintaining compensation accuracy
Solution Approach 2:
The patent replaces the mechanical approach of using multiple physical sensors on both motor shaft and output shaft with an integrated electronic feedback system. The feedback circuit processes electrical signals from the single angle sensor and motor internal information to achieve the same backlash compensation function, reducing sensor quantity while maintaining precision
Data Source
AI summary
Position control is performed with high accuracy with a smaller number of sensors. An actuator device includes: a motor whose rotation is controlled by a drive circuit; a gearbox that decelerates or accelerates torque of the motor; an angle sensor that detects a rotation angle of an output shaft of the gearbox; and a feedback circuit that generates feedback for control of the motor on the basis of internal information of the motor used in the drive circuit and the rotation angle of the output shaft detected by the angle sensor.