A double variable control load sensing system for electric hydraulic excavator

Traditional electric excavator only uses the electric machine to replace the engine and simulate its original working mode, which will not give full play to the advantages of the electric drive technology and result in poor control performance as well as low energy efficiency. In this paper, a load sensing system based on displacement adaptive and variable speed control is proposed for electric excavator to extend the flow matching range of power train system and satisfy the flow demand under different load conditions. Furthermore, a novel control strategy based on the hierarchical differential pressure control is studied. Through the control strategy, the novel load sensing system can adjust the load sensing pressure difference in stages without mutual interference, so as to maintain the power train system operation in high efficiency area, and reduce the energy loss of the valve. To verify the feasibility of the system and control strategy, the simulations and experimental test are carried out. The results show that the system and control strategy can improve the control performance effectively. The energy consumption can be also decreased by 19%e70%. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This paper proposes a load sensing system based on displacement adaptive and variable speed control for electric excavator, as well as a novel control strategy based on hierarchical differential pressure control. By utilizing these methods, the control performance of the electric excavator can be effectively improved, and energy consumption can be reduced by 19%e70%.