Collaborative Synchronization Digital Control for Double Hydraulic Cylinders

By researching the synchronization motion of double hydraulic cylinders controlled by high-speed on-off valve, the paper aims to solve the shortage of current hydraulic synchronization system with low synchronization precision. The flow characteristic of high-speed on-off valve with pulse width-frequency modulation is researched compared with pulse width modulation. The mathematical equations of the double hydraulic cylinders are formulated with bulk-cavity-node method in MATLAB/Simulink. The collaborative synchronization control is analyzed and the compound algorithm of collaborative synchronization control and pulse width-frequency modulation is simulated compared with collaborative synchronization control. The hydraulic loop is set up to verify the simulation result with the proposed control algorithm on the FESTO platform. The research finds that (1) the pulse width-frequency modulation control can be linear to the flow of high-speed on-off valve on the duty bound of 0~100%; (2) the collaborative synchronization control is effective to eliminate the displacement error between the double cylinders which results from the different load environment and other disturbance.