摘要

Generally, pressure oscillation has negative effect on hydraulic crane system which requires high dynamic stability under a flexible operating condition. In order to reduce the hydraulic pressure oscillation, a self-tuning fuzzy proportional-integral-derivative control strategy is proposed for improving the control performance of hydraulic crane. In this article, a fuzzy proportional-integral-derivative controller which consists of a proportional-integral-derivative controller and a fuzzy inference unit with two inputs and three outputs is designed for valve control. Both fuzzy proportional-integral-derivative control and traditional proportional-integral-derivative control are simulated using MATLAB based on the model of hydraulic crane. Simulation experiments are conducted with different crane tip velocities. The experimental results show that pressure amplitude reduced about 25% at low velocity and pressure oscillation of hydraulic cylinder is suppressed comparing with traditional proportional-integral-derivative controller. In addition, fuzzy proportional-integral-derivative control enables a smoother variation and a higher accuracy in changing processes of joint angle and crane tip position. The performance of the hydraulic crane is improved.