Servo Motor Starting Control Using Incremental Encoder Signals
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Solution Overview
Problem
Current servo motor starting control methods rely on Hall devices, which increase costs and reduce stability due to additional circuit components, and limit accuracy to six possible angle regions, making them inefficient for high-performance applications.
Innovation Solution
A method using incremental encoder rotor rotation signals (A, B, and Z) to estimate the starting angle position of a servo motor by determining magnetic field directions and accumulating possible position regions, eliminating the need for Hall devices and allowing for higher accuracy and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Hall devices are used to detect starting position, then position detection is enabled, but cost increases and stability decreases due to additional circuit components
Solution Approach 1:
The patent extracts and removes the Hall device from the encoder system, relying solely on incremental encoder signals (A, B, Z phases) to detect the starting position. This eliminates the need for additional Hall sensor circuits while maintaining position detection capability through software-based analysis of encoder signal transitions.
Solution Approach 2:
The patent replaces the magnetic field-based Hall effect detection with a signal-processing approach that uses electrical encoder outputs. By analyzing the transition sequences of A, B, and Z phase signals, the system substitutes physical Hall sensor measurement with electronic signal analysis, reducing hardware complexity.
2Measurement precision
If Hall devices are used, then starting position can be detected, but accuracy is limited to six possible angle regions
Solution Approach 1:
The patent implements a dynamic determination process where the starting angle region is not fixed but calculated based on the actual transition sequence of encoder signals. The system dynamically identifies which of the six possible regions (each spanning 60 degrees) contains the starting position by analyzing the order in which A, B, and Z phase transitions occur, enabling flexible and accurate angle detection.
Solution Approach 2:
The system uses feedback from the incremental encoder's A, B, and Z phase signals to continuously refine the determination of the starting angle region. By monitoring signal transitions and using this feedback to update the position estimate, the system achieves higher accuracy than fixed-region methods while maintaining adaptability to different starting positions.
3Adaptability or versatility
If more circuit components are added to improve detection capability, then functionality is enhanced, but stability decreases and maintenance cost increases
Solution Approach 1:
The patent makes the incremental encoder serve multiple functions: it provides both motor position feedback during operation and starting position detection during initialization. By designing the system to extract maximum information from the existing A, B, and Z phase signals, the encoder becomes a multi-functional component that eliminates the need for separate Hall device circuits, thereby improving reliability without sacrificing functionality.
Data Source
AI summary
A method for controlling starting of a motor is described, which is mainly applicable to estimate a possible initial position of a rotor of a motor by detecting a rotor rotation signal of the motor, and find out a most possible initial position of the rotor after making statistics. In the method for controlling the starting of the motor, a starting angle position region of the motor is calculated simply by using the rotor rotation signal of the motor, without additionally arranging a Hall sensor, so as to save a cost of a Hall device and an assembling cost. Furthermore, accuracy for estimating the starting position region can be increased according to an accuracy specification of products, thereby achieving a high flexibility.