In terms of poor controllability of motor speed, the drum speed of the anti-explosion hydraulic hoister is fed back and controlled in closed loop. An electrohydraulic servoproportional speed regulation systems for anti-explosion hydraulic hoisters is proposed. Two control constructions are formed, the pump controlled motor system with/without position loop (PCMWP, PCMP, resp.) according to whether the displacement of pump is controlled in closed loop or not. Experiments of two control constructions are made under overflow load and weight load. Experimental results indicate that the presented system can simulate the process of anti-explosion hydraulic hoisters, and closed control loop could promote the control performance of hoister. Compared to the PCMP, the PCMWP is characterized by more stability with better speed follow and better robustness. At the same time, the cage instantaneous sliding at start-up and the pressure shock while braking are avoided effectively relying on the cooperation between the driving system and brake system, which ensure the security for hydraulic hoisters; the method of position correction by using travel switches at the end greatly enhances the precision of parking position.
Design and Simulation of Double Closed-loop DC Motor Speed Regulation System with Fuzzy PID Controller