Force Fighting Research of Dual Redundant Hydraulic Actuation System

The force fighting exists between active channels of redundant system, which affects the output precision, shortens operation life and leads to damage. Based on the nonlinear model of dual redundant hydraulic actuation system, this paper investigates the influences of each parameter by setting them differently in two channels and brings us guidance to reduce the force fighting in design and manufacturing process. Then three kinds of strategies applied in various situations are listed and compared with each other. The position and speed difference fuzzy tuning PI control strategy is proved to be most effective with high dynamics, small static force fighting and less force fighting oscillations, because this method has the ability to adjust its parameters online according to the differences of two channels.