Adaptive Notch Filter Tuning for Close Resonance Feedback Control
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Solution Overview
Problem
Existing automatic adjustment methods for feedback control systems struggle to effectively set the center frequency and notch width of notch filters to suppress resonance characteristics, especially when resonance frequencies are close, leading to estimation errors and inadequate resonance suppression.
Innovation Solution
An automatic adjustment method using adaptive notch filters in series with a highpass filter to extract and eliminate vibration components, allowing for the appropriate setting of filter parameters, including center frequencies and notch widths, to optimize resonance suppression without the need for bandpass filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If two bandpass filters with different bandwidths are used to extract vibration components from two resonance characteristics, then automatic adjustment of center frequencies can be achieved, but when resonance frequencies are close, both vibrations are extracted from one BPF, causing estimation errors and failing to suppress resonance effectively
Solution Approach 1:
The patent divides the resonance suppression task into multiple independent notch filters (first NF and second NF) with different center frequencies. Each NF is equipped with its own adaptive element that independently adjusts its parameters. This segmentation allows each filter to target specific resonance frequencies without interference, solving the problem of estimation errors when resonance frequencies are close.
Solution Approach 2:
The patent employs adaptive elements that dynamically adjust the center frequencies and notch widths of the notch filters in real-time based on the detected vibration characteristics. This dynamic adaptation enables the system to automatically track and suppress resonance frequencies even when they are close together, improving frequency estimation accuracy while maintaining automation.
2Productivity
If the gain of the feedback controller is increased to improve system response, then productivity improves, but resonance characteristics prevent gain increase due to mechanical system resonance
Solution Approach 1:
The patent introduces notch filters as intermediary elements between the feedback controller and the mechanical system. These NFs act as mediators that selectively attenuate resonance frequencies while allowing the feedback controller to operate at higher gains. The adaptive elements continuously adjust the NF parameters to maintain effective resonance suppression, enabling improved productivity without sacrificing reliability.
3Reliability
If multiple notch filters are used to suppress multiple resonance characteristics, then resonance suppression effectiveness improves, but the complexity of setting filter parameters (center frequency, notch depth, notch width) increases significantly
Solution Approach 1:
The patent implements adaptive elements that automatically adjust the center frequencies and notch widths of the notch filters based on the detected vibration characteristics of the mechanical system. This self-service capability eliminates the need for manual parameter setting and adaptation, reducing the complexity of filter parameter configuration while maintaining effective resonance suppression across multiple resonance characteristics.
4Extent of automation
If adaptive notch filters are used to automatically adjust center frequency, then automatic adjustment is achieved, but the notch width cannot be optimized, resulting in inadequate resonance suppression when notch depth or width is inappropriately set
Solution Approach 1:
The patent employs adaptive elements that dynamically adjust both the center frequencies and the notch widths of the notch filters in real-time. This dynamic parameter adaptation allows the system to automatically optimize both the frequency positioning and the bandwidth of each NF, ensuring effective resonance suppression without requiring manual intervention for parameter tuning.
Data Source
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AI summary
The purpose of the present invention is to provide: an automatic adjustment method for automatically adjusting, in a short time period, a feedback control system including a control means for suppressing the resonance characteristics of a mechanical system; and a feedback control apparatus. The above-described purpose is attained by an automatic adjustment method for an FB control system including an automatic adjustment device for automatically adjusting parameters for two stages of actual notch filters provided in series on a subsequent stage of an FB controller. The automatic adjustment device includes a highpass filter, two stages of adaptive notch filters in series, and an adjuster. The highpass filter extracts vibration components from a response made by the FB control system. The vibration components are inputted to the first-stage adaptive notch filter. The adaptive notch filters perform adaptive convergence so as to eliminate main vibration components in input signals. The adjuster determines whether or not the vibration components can be eliminated by the adaptive notch filters, performs determination as to completion of the adaptive convergence, obtains the differences in parameters from the respective adaptive notch filters, and sets, on the basis of the results thereof, filter parameters for the actual notch filters.