A suboptimal controller design method for the energy efficiency of a load-sensing hydraulic servo system

Abstract

The dynamic characteristics of a load-sensing hydraulic servo system are complex and highly nonlinear and, furthermore, the stability is critically deteriorated compared with that of the conventional hydraulic servo systems. Another property of the systems is that the setting value of the pump pressure-compensator considerably affects energy efficiency as well as control performance of the system. These features significantly add complexity to the controller design of the load-sensing systems. To guarantee satisfactory control performance and energy efficiency of the system an effective controller design method, therefore, needs to be developed. This paper considers a suboptimal PID control for the velocity control problem of a load-sensing hydraulic servo system. To show the effectiveness of the controller a series of simulations and experiments were performed. Both results show that the proposed suboptimal controller can produce satisfactory response characteristics and yield an effective trade-off between control performance and energy efficiency of the system.