Research on Control and Energy Consumption Characteristics of Distributed Independent Electrical-Hydraulic Actuator Control System Used on Excavators

Due to the low efficiency of internal combustion engine (ICE) and throttling losses of load-sensing (LS) system, conventional excavators, which employed ICE with LS system as a power source, have high-energy waste. To avoid this problem, a distributed independent electrohydraulic actuator (iEHA) that directly driven by an electric motor is designed for excavators, and a speed control strategy based on mode switching and pump map is proposed. The results of the proposed control strategy are carried out to verify the velocity stability. Besides, different signal delays for switching valve are explored to obtain better control characteristics. Furthermore, the influence of different precharged pressures of accumulator is explored when boom and arm share an accumulator. Results demonstrate that the energy efficiency of iEHA system improves from 19.19% to 59.56% compared to LS system, and the comprehensive response performance is better when signal delay time is 0.1 s and response speed of system increases by 16.6% compared to no delay, and the system can achieve good results when the precharged pressure is set to 20 bar.