Abstract
In hydraulic motion control industries, independent metering valves control system (IMVCS) can effectively improve the control performance of the system, furthermore, it has prominent potential in energy-saving. In IMVCS, the meter-in and meter-out orifices are regulated by two independent valves, which increases the control degrees of freedom. In some working conditions such as lifting where the load is steady, a double pressure compound control (DPCC) strategy that controls inlet and outlet cavities simultaneously can be applied for better dynamic performance. In this paper, a double DPCC strategy is proposed to regulate the pressure of both meter-in and meter-out chambers of a cylinder. Firstly, the control algorithm based on the two-level fuzzy PID (FPID) is designed, which contains a spool displacement controller as an inner loop and a pressure controller as an outer loop. Then, the pressure dynamic characteristics of the system under the IMVCS are studied. The simulation model is established using AMESim-Simulink co-simulation, and its key parameters are identified through experiments. The simulation results show that the dynamic characteristics of the actuator can be increased effectively with two-level fuzzy PID control algorithm and DPCC strategy. The adjusting time and overshoot of cavity pressure can be significantly decreased with them.
