A Study on Application of H Infinity Control Theory to an Electric-control Variable Displacement Pump.

H infinity control theory was applied to control of a variable displacement piston pump. Angle of the pump's swash plate was detected by means of a position sensor attached on a control piston. The position signal was fed back to a controller and a control input signal was added to a proportional flow control valve so that the control piston position follows the demanded signal. A control system for pump displacement was designed by applying H infinity control theory considering changes in pump speed and load pressure. The control system was examined experimentally on a test bench. Results demonstrated that the system shows stable and quick responses under different pump operating conditions.