This example shows a closed-circuit hydraulic actuator driven by a variable-speed pump. The actuator is arranged as a closed fluid system with two replenishment valves (check valves) and a spring-loaded accumulator serving as a replenishment reservoir. The pump speed is controlled by the difference between the commanded and measured piston position. The actuator acts against a spring, a damper, and a time-varying load.
This plot shows the position of the piston and the flow rate through the pump.
This plot shows the pressures inside the cylinder chambers and the time-varying load on the piston.