Variable-Speed Pump-Controlled Three-chamber Cylinder System for Hydraulic Boom with Feed-Forward LADRC

With the increasing fossil fuel crisis and environmental degradation, energy-saving has been one of the fluid power transmissions’ priority research areas. In a conventional hydraulic boom, throttling and potential energy losses result in poor energy efficiency and extra rising of fluid temperature. To boost the energy efficiency of a hydraulic boom, this paper proposed a variable-speed pump-controlled three-chamber cylinder system for hydraulic boom with feed-forward plus linear active disturbance rejection control (LADRC). In the proposed system, chambers A and B of the three-chamber cylinder are controlled by two variable-speed fixed-displacement pumps and the third chamber C is connected to a hydraulic accumulator to balance the weight of the boom. Firstly, the model of the variable-speed pump-controlled three-chamber cylinder system is built in Matlab/Simulink. Further, the mechanical model of a 1-ton excavator is established, and the proposed system is applied to the boom. Secondly, a compound controller combining speed feed-forward and LADRC is designed. Thirdly, simulations were performed under boom up and down while keeping the arm and bucket cylinders fully retracted. The position control performance and energy consumption are analysed and compared. The results show that, compared to the PID and speed feed-forward PID control, the proposed controller has a lower position tracking error (less than 2.66%). Compared with the variable-speed pump-controlled differential cylinder system, the proposed system can save energy by 43.51% when considering energy recovery. Therefore, the proposed system has good position tracking performance and has the potential to be applied to different types of heavy-lifting equipment driven by hydraulic cylinders.