Performance analysis and experimental investigation to pneumatic-hydraulic-combination-control system

To remedy the disadvantages of conventional pneumatic servo system, pneumatic-hydraulic-combination-control (PHCC) servo system is put forward, where the liquid medium is led into the conventional pneumatic servo system and controlled in closed-loop simultaneously. High-speed on-off valves are used and controlled with pulse width modulation (PWM) in this system. The system is simulated and tested with typical signal input via a single neuron adaptive controller based on the established state equation. The results of simulation and experiments show that PHCC system achieves a better tracking performance of typical signals than conventional pneumatic servo system, also realizes location without overshoot as well as higher position stiffness and accuracy.