A Multi-Pump Multi-Actuator Hydraulic System with On-Off Valve Matrix for Energy Saving

Load coupling effect in a traditional one-pump multi-actuator hydraulic system usually results in considerable throttling losses. To solve the problem, this paper develops a multi-pump multi-actuator hydraulic system, where an on-off valve matrix is used to match the supplied flow of pumps to the required flow of actuators. Thus, energy saving can be achieved when a proper control strategy is applied to decouple the multi-actuator system. Based on system modeling, a three-level control strategy is proposed and optimized. The upper level determines the states of the on-off valve matrix by using dynamical programming technique. The middle level generates the velocity control mode of the hydraulic actuators. The lower level is used to govern the actuator velocity by controlling the variable-displacement pumps and the throttling valves together. Numerical simulations are implemented in MATLAB to verify the effectiveness of the novel system as well as the control strategy. It is shown from the results that significant energy-saving and good steady performance can be realized. This hydraulic system has good potential in the applications of energy-efficient mobile construction machinery.