Control of a Servohydraulic Positioning System Using State-Space Controller with Grey Forecasting.

Abstract

In this paper, a new approach combining the state variable feedback control and the grey forecasting is presented for the position control of a servohydraulic cylinder.In industrial implementations, it may be interesting to minimize the number of sensors because of cost considerations.Therefore, for our servohydraulic positioning system, only one position sensor will be employed and the other necessary states(that is:velocity and acceleration)are obtained through numerical derivation of the position signal.Applying the method of numerical derivation, which is the simplest way for the acquisition of velocity and acceleration signals, does not require a known system mathematical model.Disadvantages, however, are the phase-lag problem of the derived signals and the consequent overshoot of the output response.Owing to the predictive property of the introduced grey forecasting, the experimental results show that both the phase-lag of the derived signals and the overshoot of the response curve are effectively compensated.