Resolver Position Error Compensation Using Angle Tracking Observer
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Solution Overview
Problem
Existing methods for compensating position errors in resolvers are limited to constant speed conditions, failing to effectively address errors across the entire speed range, which restricts the performance of permanent magnet synchronous motors in high-performance applications.
Innovation Solution
An apparatus and method utilizing an angle tracking observer (ATO) within a resolver-digital converter to calculate and compensate for position errors across all speed ranges by measuring and storing position errors at a specific speed, allowing for adaptive correction based on current electrical angular velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position error is measured and compensated at constant speed using existing methods, then position error compensation is achieved at that specific speed, but position error compensation performance deteriorates across the overall speed range
Solution Approach 1:
The patent transforms the static compensation approach (fixed speed) into a dynamic approach by introducing speed adaptation mechanisms. The ATO (adaptive tuning observer) continuously adjusts compensation parameters based on current speed, and the position error compensator dynamically selects appropriate compensation values from lookup tables based on instantaneous speed, enabling effective compensation across the entire speed range rather than being limited to a single constant speed condition
Solution Approach 2:
The patent changes the parameter of operating speed from a fixed constant to a variable parameter. By measuring position error at multiple speeds and storing speed-dependent compensation data in lookup tables, the system adapts compensation parameters according to the current operating speed. This parameter transformation allows the compensation mechanism to remain effective whether the motor operates at low speed, high speed, or any intermediate speed point
2Reliability
If position error compensation is optimized for high performance applications, then motor control performance improves, but the system becomes restrictively limited to specific operating conditions
Solution Approach 1:
The patent creates a universal compensation system that functions effectively across all operating conditions. The lookup table stores compensation data for multiple speed points, and the position error compensator interpolates between these values to provide accurate compensation at any speed. This multi-functional approach allows the same compensation mechanism to serve both high-performance requirements and broad operating condition flexibility, eliminating the restrictive limitation to specific operating conditions
Data Source
AI summary
An apparatus and method are provided for compensating for a position error of a resolver that compensates for positions in the overall speed range using resolver position error measured at a specific speed by providing an angle tracking observer (ATO) for calculating angle information. The ATO compensates for the position errors in the overall speed range based on the position errors measured at the specific speed, to an inside of a resolver-digital converter. The method includes digitalizing detected position information of the motor rotor and receiving the digitalized position information from a resolver-digital converter to measure the position error. An electrical angular velocity of the position error is determined and the position error at the electrical angular velocity 0 is calculated and stored. The position error at a current electrical angular velocity is converted into and compensated for using the calculated position error based on the current electrical angular velocity.