The Research On Pwm Hydraulic Servo System Based On High-Speed On/Off Valve

The research object of this paper is to study the high-speed on-off valve controlled PWM hydraulic servo system, In order to achieve the real time control, the hydraulic cylinder system which controlled by high-speed on-off valve are analyzed in detail, based on the S7-200PLC, the PID controller are designed. And use AMESim simulation software to constructs the simulation model of valve control hydraulic cylinder position servo system, complete experimental research for the system circuit. The experimental results show that proposed control method is effective.Firstly, Digital hydraulic control technology and the development of high-speed on-off valve are analyzed. According to some related theories, such as PWM pulse width modulation technology, the work principle and characteristic of the high-speed on-off valve, The valve control PWM hydraulic servo system is designed, and the mathematical model of valve-controlled hydraulic cylinder system is deduced and established. Then, the AMESim simulation is carried on. The simulation results show the static and dynamic features of the electromagnetic switch valve, and the simulation analysis the response characteristics of valve control system with different conditions are brought out. Secondly, in order to build the experiment platform of high-speed on-off valve control hydraulic servo system, the hardware system is designed, with S7-200PLC containing high-speed pulse output PWM module as its core. The displacement sensor signal from the PLC which is compared with the reference signal calculated by the PID control arithmetic, then use PWM high-speed on-off to control high-speed on-off valve, so that the system realize high precision position servo. Then use Lab VIEW as program languages to design data acquisition programs, thus process parameters can be acquired, disposed, shown and saved.Finally, several basic debugging and experiments are taken on the platform of valve-controlled hydraulic cylinder position servo system. The simulation results have been confirmed by the experiment results, proving the validity of the simulation model and the rationality of the system design.