Study On Excavator Energy-saving Control Technology Based On Model Prediction

Hydraulic excavator has become an integral part of mining tools in modern engineering construction, which greatly promoted the development of the global economy. Because it is widely applied, so the energy consumption of hydraulic excavator can not be ignored. Especially the current global energy is less and less, and energy saving of the environment is promoted, therefore the research of energy-saving technology about hydraulic excavator is particularly important. In addition, compared with abroad, the domestic excavator technology is started lately. the overall performance has a certain gap. which seriously affects the competitive of hydraulic excavator in the global market. In this paper, a certain type of domestic hydraulic excavator is discussed and studied, its structure and principle of the power system is analysed deeply. Based on a new modeling method, a scheme of power saving is proposed, the single neuron PID control algorithm is used to achieve the control of variable pump displacement, the experimental research and analysis of SIMULINK simulation validated the control strategy and algorithm. In this paper, the main work is as follows:(1) Based on the main energy loss of hydraulic excavator, the energy-saving technology about china and abroad is compared comprehensively, the classical energy saving hydraulic system is introduced, the principle of variable pump power regulation is analyzed, which is set as basement in the power of diesel engine and variable pump matching and control strategy.(2) The key part of the excavator power was introduced in great detail, and the working characteristics of the engine and variable pump was analyzed, then, the author built a diesel engine throttle actuator and variable pump control dynamics model, and simulated the model by the computer simulation software MATLAB/SIMULINK to verify the practicality and accuracy. Because the hydraulic excavator power system is of strong nonlinear,large time delay and time-varying,this paper adopted the support vector machine, widely used for modeling in recent years in the nonlinear modeling, to avoid excessive parameter hypothesis in the process of establishing the mechanism model. And look for the better kernel parameter and penalty factor of model by the particle swarm optimization algorithm, At last, verify the accuracy of the mode through the Libsvm toolbox.(3) The parameter setting of conventional PID controller needs generally a wealth of practical experience, which is difficult to get good control effect in the course of the study, this paper predicts used the single neuron PID control algorithm for closed loop power control system of excavator based on the experimental model of variable displacement pump, The variable pump control simulation model is established and the simulation results were observed and analyzed by the MATLAB/SIMULIK simulation tool.(4) The real vehicle experiment according to the control strategy and control algorithm. The energy-saving control procedures was written in the ECU controller, and finish the real vehicle experiment according to the experimental scheme to compare the simulation results with the real vehicle test results. Experimental results show that the control strategy and control algorithm proposed in this paper can adjust the current control variable displacement pump and hold steady engine speed, then reduce the fuel consumption.