Study On Power-Matching Control Of The Hydraulic Excavator’s Power System

Energy saving is an important trend in the development of world industry, as the main equipment for digging, hydraulic excavator has a low efficiency. With the development of electromechanics and application, the use of electronic control mode helps to reduce the energy loss of hydraulic excavator. In this paper, the author adopt the electronic control way to realize the power control and power saving. The main research works are as follows:1、The engine’s modeling methods are analyzed, after that the engine’s quasi linear model is selected for the research in the purpose of controlling engine’s speed. The model takes throttle Angle, load torque value, engine initial speed as the inputs, the speed after torque is changed as the output.2、The power control theory of electronically controlled variable pump are analyzed, and the movement of the pump’s displacement adjusting mechanism is studied. A simulation model that takes the load pressure、engine speed and electromagnetic proportion valve current as the inputs, hydraulic pump flow as the outputs is established.3、The reason of energy loss in the process of power match is analyzed, and a control strategy that in the light load, normal load mode, engine’s power is set at the fuel economic curve, in the overloaded mode, the engine’s power is set near to the external characteristic curve is proposed. The control strategy combine energy saving and the dynamic performance as the aim4、Combined with engine and hydraulic pump model, the single neuron PID control is selected to control engine’s power and pump’s power. In the platform in SIMULINK, the simulation process is executed. The simulation results and experiment results show that the single neuron PID algorithm can achieve the control requirements of engine’s power and hydraulic pump’s power.4、According to the characteristics of the test signal and the target for controlling, the measurement and control system based on the controller、 USB/CAN device、Lab VIEW is designed, the testing result shows that the system can achieve the test data acquisition and control function.