Iterative Learning Control for Switched Reluctance Motor Direct-drive Electro-Hydraulic Position Servo System

Abstract

Aiming at the serious saturation and dead zone nonlinearity, time-variability and time lag existing in pump-controlled cylinder electro-hydraulic servo system droved by SRM (Switched Reluctance Motor) directly, the ILC (Iterative Learning Control) method was put forward to conduct the position servo control for hydraulic machine slider in this thesis. The mathematical model of SRM direct-drive electro-hydraulic servo system was founded. The control algorithms of open loop and closed loop ILC were designed according to the principle of ILC. The convergence characteristics and shift curve tracking abilities were researched by simulations and experiments. The results show that the convergence speed and accuracy of closed loop ILC exceed open loop by a big margin, and the ILC can effectively eliminate the influences of dead zone and time lag nonlinearity, and the closed loop ILC method can raise control accuracy of pump-controlled cylinder system remarkably compared with PID control.