Research on hydraulic pump displacement control using PI and feed-forward compensation

Abstract

The pump-displacement-controlled actuator offers a very promising alternative and energy-saving solution for many applications in construction machines. It has proven to be with high fuel economy by eliminating the metering losses associated with hydraulic valves. However, actuator oscillation is observed while working with fluctuated velocity or dynamic loads due to slow dynamic response and low tracking accuracy of the pump-controlled actuator. To improve control quality, a new proportional-integral algorithm combined with feed-forward compensation is put forward in this article. Based on the analysis of the swash plate adjustment mechanism, the state-space equation is established. And then, simulation and experimental studies were carried out. Both simulation and experimental results show that the new controller based on proportional-integral algorithm with feed-forward compensation achieves higher dynamic response and tracking accuracy than the conventional proportional-integral controller. And the actuator oscillation is eliminated.