Resolver Noise Filtering via Lissajous Pattern Matching
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Solution Overview
Problem
In eco-friendly vehicles, the resolver output signals are often distorted by noise, leading to inaccurate motor angle recognition and reduced motor control stability, which can cause torque control errors and instability during speed and current control.
Innovation Solution
A motor control device that uses reference Lissajous values to correct and stabilize the motor angle by identifying external noise and converting output signals into sine and cosine signals, allowing for precise control and noise filtering without the need for additional shielding or filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If additional shielding or filters are used to reduce noise interference, then noise resistance is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces physical noise filtering mechanisms (shielding, filters) with a software-based signal processing approach. The controller digitally processes resolver output signals to extract accurate motor angle information even in the presence of noise, substituting mechanical/physical noise reduction methods with computational algorithms that analyze signal patterns and calculate angles without requiring additional physical components.
2Measurement precision
If resolver output signals are used directly for motor control, then device complexity is reduced, but measurement precision deteriorates due to noise distortion
Solution Approach 1:
The controller performs preliminary signal processing and analysis on the resolver output signals before using them for motor control. It pre-calculates motor angles by analyzing signal patterns, detecting noise conditions, and applying appropriate processing algorithms in advance, ensuring accurate angle recognition is established before control actions are executed.
Solution Approach 2:
The system implements feedback mechanisms where the controller continuously monitors resolver output signals, compares processed angle information with expected values, and adjusts processing parameters accordingly. This feedback loop ensures that noise distortion is compensated in real-time, maintaining measurement precision through iterative refinement of angle calculations.
Data Source
AI summary
A motor control device includes: a storage configured to store reference Lissajous values; and a controller configured to apply an excitation signal to a resolver; receive an output signal output from the resolver, to obtain a Lissajous value corresponding to the received output signal, to determine that an external noise is input when the obtained Lissajous value is different from the reference Lissajous values, and to control driving of a motor based on the obtained Lissajous value when the obtained Lissajous value is equal to any one of the reference Lissajous values. A vehicle having the motor control device may further include a battery configured to transmit power to the motor and to be charged by regenerative braking of the motor.