Adaptive Piecewise Linear Controller for Servo Mechanical Control Systems

Abstract

In this paper, an adaptive piecewise linear control scheme is proposed for improving the performance and response time of servo mechanical control systems. It is a gain stabilized control technique. No large phase lead compensations or pole zero cancellations are needed for performance improvement. Large gain is used for large tracking error to get fast response. Small gain is used between large and small tracking error for good performance. Large gain is used again for small tracking error to cope with disturbance. It gives an almost command independent response. It can speed up the rise time while keeping robustness unchanged. The proposed control scheme is applied to a servo system with large time lag and a complicated electro-hydraulic velocity/position servo system. Time responses show that the proposed method gives significant improvements for response time and performance.

Single-phase Shunt Active Power Filter by Using Piecewise Linear Look-up Table Controller

“…Moreover, in order to decrease more on the rule table membership functions and complexity of FPIC, a single input Fuzzy PI controller (SIFPIC) is introduced [13]. The SIPFIC is achieved by employing a 'signed distance method', which will have only a single input instead of two inputs for typical FLC, hence can simplify the FPIC control surface to a piecewise linear approximation [11], [14]. This technique has been implemented in APF, that proved its capability in compensating reactive power and successfully mitigating current harmonic distortion [2].…”

“…In single input single output SIFPIC, the relationship of input and output can be mapped into a piecewise linear approximation using PL-LTC, as depicted in Figure 1 [11]- [14]. Apparently, the slope λ is 1, since every increment point ford will result in identical point for ẏ.…”

Adaptive PID and Model Reference Adaptive Control Switch Controller for Nonlinear Hydraulic Actuator

“…Some efforts have been done toward developing control strategies for such systems [14][15][16][17][18][19][20][21][22][23][24]. There are mainly two control strategies: PID control and Model Reference Adaptive Control (MRAC).…”