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.
ASYMMETRIC FUZZY PID CONTROL FOR PNEUMATIC ROBOT POSITION CONTROL SYSTEM
