Design of flow and pressure coupling controller for independent metering valves control system

Compared with traditional valves control system, independent metering valves control system (IMVCS) broke down the mechanical coupling of the meter-in and meter-out orifices, so that it increased the control degrees of freedom. Usually two spools were used to determine one actuator's state in IMVCS. The key difficulty was to coordinate the opening displacement of two spools that can output pressure and flow according to control strategy. This paper introduced the components and working principle of IMVCS. A flow and pressure coupling controller was designed to control both velocity of piston and pressure in each chamber. A SYS/BIOS based embedded operating system was adopted for fast response. Large set of sensors can be integrated which their amplifying circuits were designed on board. The IMVCS used dual close loop control to monitor and modify pressure and flow in real-time. Four types of threads were provided to schedule tasks. The real-time multitasking control software was developed. To verify the control strategy and PCB'A, a preliminary experiment showed the results of step response and sine signal tracking that two spools worked by onboard controller.