Fuzzy switching control between position and force for electro-hydraulic servo system

Due to the differences of control methods and control parameters between position control and force control,when the position control and the force control switch,there are jitters. To solve this problem,a fuzzy switching control method based on correction factor was proposed. The electro-hydraulic force-position servo system was analyzed theoretically,and the mathematical models of the force control and the position control are established. When the hydraulic cylinder contacted with the object,fuzzy control method was adopted to execute the force control,when the hydraulic cylinder got away from the object,PID was used for position control to maintain the unchanged position of the hydraulic cylinder. A fuzzy switching control method based on correction factor was put forward to reduce the jitters during switching. Finally the experiments were carried out under the electro-hydraulic servo integration test bed. The experimental results show that the proposed fuzzy switching control method effectively weakens the jitters and transitions during switching,and ensures a smooth transition between the two control strategies.