Real-time pole placement control of the rugged electrohydraulic system

Abstract

Features like high power to weight ratio, self lubrication, heat dissipation and fast control make hydraulic systems superior to mechanical and electric systems. Such systems are used in aircraft, motion simulators, metal-cutting, universal-testing machines and material handling for heavy industries. For a precision operation, it is usual to employ electrohydraulic servo systems that are more sophisticated than systems with proportional valve. Due to larger deadband and higher flow nonlinearities, the low-cost rugged proportional valves together with standard PID controllers result in poor response for tracking demand. A controller has been designed through a novel state estimation algorithm and the usual pole placement (PP) technique by carefully choosing the operating points. One high friction cylinder and another industrial grade cylinder have been driven separately by using the same proportional control valve. The designed controller has yielded better performance compare to the PID controller.