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International Standard Serial Number:
ISSN 1001-4551
Sponsor:
Zhejiang University;
Zhejiang Machinery and Electrical Group
Edited by:
Editorial of Journal of Mechanical & Electrical Engineering
Chief Editor:
ZHAO Qun
Vice Chief Editor:
TANG ren-zhong,
LUO Xiang-yang
Tel:
86-571-87041360,87239525
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No.9 Gaoguannong,Daxue Road,Hangzhou,China
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meem_contribute@163.com
Abstract: Aiming at the problem that the surplus force affected the loading accuracy in the electro-hydraulic servo system, an improved feedforward control strategy was proposed to suppress the surplus force. Firstly, the reasons for the surplus force in the four-axis electro-hydraulic loading system of the steering knuckle bench testing machine were analyzed, and the mathematical model between the single-axis loading force and the control signal was established. Then, considering the complexity of position disturbance motion state and the compensation link’s phase lagging of the feedforward control, an improved feedforward control strategy including the fast Fourier transform (FFT) of spectral sequence transformation, the compensation link and dual back propagation (BP) neural network phase correction was used to suppress the surplus force. Finally, the Simulink simulation analysis and experimental verification of the strategy were carried out. The research results show that when the frequency of position interference is 1Hz, 3Hz, and 5Hz, the phase lags of the compensation link are 1.66°, 4.76° and 7.92°; the ratios of the dynamic phase correction range to the effective correction range are 0.88, 0.61, and 0.46; with the increase of the position interference frequency, the phase lag of the compensation link increases, the relative variation range of the corrected phase gradually decreases, and the suppression effect of the method on the surplus force is more obvious.
Key words: electrohydraulic servo system; loaded precision; fast Fourier transform(FFT); neural network; phase correction algorithm; spectral sequence transform FFT algorithm; compensation link