Study On Energy-Saving Technology Of Hydraulic Excavator Based On Power Match

The excavator is an important construction machinery, which is widely used in road construction, water conservancy construction, mine mining and so on. Power utilization ratio of the excavator is a research hotspot and direction all through. Energy saving efficiency directly influences the equipment's economy and dependability. Combined with the project of WLY80 hydraulic excavator, the power matching control system among engine, hydraulic system and load is researched. The main contents are as follows:1) Firstly, the significance of the project and the trends of hydraulic excavator's development and energy saving control system are introduced. The gap of energy saving technology between homemade and foreign excavators is analyzed. Problems to be resolved are pointed out.2) Secondly, based on the analysis of excavator's hydraulic system, the main types of power loss are introduced. Technologies of current typical energy saving are analyzed and compared, and then more efficient energy saving methods are put forward.3) Thirdly, combined with design of WLY80 hydraulic excavator, energy saving hydraulic system is constructed, and power matching of the machine is calculated. Based on the analysis of characteristics of diesel engine and variable displacement hydraulic pump, mathematical models of diesel engine, throttle adjustment and variable displacement hydraulic pump are established. According to the working characteristics of hydraulic excavator, power matching strategies of engine-pump-load are built, and the control methods and control procedures are introduced in detail.4) Finally, based on nonlinear and delaying of hydraulic excavator's working condition, characteristics of conventional PID control, fuzzy PID control and neuron PID control are analyzed, then models of throttle controller with conventional PID control and variable displacement hydraulic pump controller with single nerve cell PID control are built. Control algorithms of the two models above are deducted and designed. Convergency and stability of the algorithms are analyzed. System modeling is simulated by MATLAB, and the results are analyzed.The simulation shows that mathematical models and the power matching method of engine and pump are feasible and the control function can meet the requirement. The algorithms of throttle control and pump control in the thesis compensated for the deficiency of conventional PID control and can meet the requirement of real time control. The energy saving method in the thesis is efficient, and provides a solid infrastructure for the design of following products.