抄録
In this research, a Linear Model Following Control (LMFC) method to reproduce the input waveform is discussed. It is difficult to control the acceleration waveform of an electrohydraulic servo system because of its nonlinear characteristics.
For controlling the acceleration waveform of the electrohydraulic servo system, the LMFC method with the reference linear model of a timedelay element is introduced.
This LMFC system has state variable feedback circuits with variable feedback gains. Since the calculations of the variable feedback gains are easily performed using a digital processor, the following control of the reference model can be achieved without any difficulty, when compared with the control of an ordinary electrohydraulic servo system.
The acceleration output waveform of the electrohydraulic servo system is evaluated by performance index J which is defined to evaluate waveform distortion.
This control method is applied to the analogue simulation circuit and experimental apparatus to confirm reproducibility of the input signal, and the results are as follows.
(1) The ideal model of the LMFC method, which is applied in the servo system to reproduce the input waveform, has a timedelay characteristic.
(2) The equivalent linearization of the electrohydraulic servo system is carried out without any difficulty.
(3) The experimental results of the LMFC method of the practical apparatus show the satisfactory performance such that J=9% for the triangular input signal with the fundamental frequency of 30Hz and the frequency characteristics of the LMFC system, which is controlled by the servo valve with a 70Hz bandwidth, show a 150Hz bandwidth.
