Motor Control Device Dual Low-Pass Filter Noise Disturbance
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Solution Overview
Problem
Conventional motor control systems face limitations in achieving high accuracy control due to the contradictory requirements of suppressing observation noise and obtaining disturbance information, which restricts effective disturbance suppression.
Innovation Solution
The motor control device employs two low-pass filters with different cutoff frequencies to correct the control input signal, allowing for the removal of observation noise while preserving disturbance information, thereby enhancing disturbance suppression accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a single low-pass filter is used to suppress observation noise, then noise suppression is improved, but disturbance information is lost
Solution Approach 1:
The patent divides the single low-pass filter into two separate low-pass filters with different cutoff frequencies. The first low-pass filter (higher cutoff frequency) preserves disturbance information while the second low-pass filter (lower cutoff frequency) suppresses observation noise. This segmentation allows simultaneous achievement of both noise suppression and disturbance information preservation, resolving the technical contradiction.
2Object-affected harmful factors
If the cutoff frequency is reduced to suppress observation noise, then noise suppression is improved, but disturbance information is lost
Solution Approach 1:
The patent segments the filtering function into two parallel paths with different cutoff frequencies. The first path uses a higher cutoff frequency to preserve disturbance information for accurate measurement, while the second path uses a lower cutoff frequency to suppress observation noise. This resolves the contradiction between noise suppression and measurement precision.
Solution Approach 2:
The patent applies different filtering characteristics to different signal components locally. By using two low-pass filters with different cutoff frequencies, the system applies appropriate filtering strength to different parts of the signal spectrum, preserving high-frequency disturbance information while suppressing high-frequency observation noise.
3Loss of information
If the cutoff frequency is increased to preserve disturbance information, then disturbance information is improved, but observation noise is amplified
Solution Approach 1:
The patent segments the filtering operation into two parallel filters with different cutoff frequencies. The first low-pass filter with higher cutoff frequency preserves disturbance information, while the second low-pass filter with lower cutoff frequency suppresses observation noise. This segmentation resolves the contradiction between preserving disturbance information and suppressing observation noise.
Data Source
AI summary
A motor control device of the present invention includes a correction input unit, a measurement unit, a first signal processing unit, and a second signal processing unit. The correction input unit corrects a control input signal outputted from a controller, and inputs a corrected control input signal into a motor. The measurement unit measures a physical quantity resulting from rotation of the motor corresponding to a control output. The first signal processing unit inputs a measurement signal representing the physical quantity inputted from the measurement unit into an inverse model 1/G of a transfer function G of a controlled object, and filters an output of the inverse model 1/G through a first low-pass filter. The second signal processing unit obtains a corrected control input signal to be inputted into the motor by the correction input unit, and filters the control input signal through a second low-pass filter.