Flow matching with combined control of the pump and the valves for the independent metering swing system of a hydraulic excavator

Abstract

Because of the throttling loss of the control valves and the overflow loss in the frequently accelerating and decelerating motion with a large inertia, the swing system of a hydraulic excavator has a high energy consumption; also, it has a poor controllability. To solve these problems, this paper proposes flow matching with combined control of the pump and the valves and an independent metering method for the swing system of the hydraulic excavator. The inlet pressure and the outlet pressure of the hydraulic motor can be controlled independently. With combined control of the pump and the valves, the flow rate can match the rotational speed of the hydraulic motor so that the overflow loss is avoided. Furthermore, we also develop a simulation model consisting of the mechanical structure of the hydraulic excavator with multi-body dynamics and an electrohydraulic system for analysing the feasibility of this swing system, and the simulation results demonstrate that this system works smoothly. After using the presented control strategies, the results of experiments show that the energy efficiency is improved and that the system can reduce the throttling loss and can obviously suppress the swing vibrations.