Electro-hydraulic Proportional Control And Simulation Analysis Of Excavator Loader Working Device

With the improvement of labor costs and the advancement of science and technology,engineering machinery with computer control as the core has become more and more popular,which further reduces the labor intensity of operators and improves work efficiency.In this paper,the load of the digging loader working device is variable and the flow control of the multi-valve valve port of the hydraulic system is unstable,which causes the working efficiency of the whole machine to be low.The electro-hydraulic proportional control system of the working device is designed.The boom is established based on the power bonding graph theory.The hydraulic system model is used to derive the state equation of the lifting condition and its dynamic analysis.According to the requirements of the working device control response speed and accuracy,the fuzzy PID controller is designed.On this basis,the excavator loader working device is established.The electromechanical and hydraulic joint simulation model simulates its actual working process,and the simulation verifies the feasibility of the above hydraulic system and controller.main tasks as follows:(1)Based on the DH principle,the kinematics equation of the working device is established,and the trajectory of the working device is analyzed.The load change during the loading process is analyzed.According to the different loading methods,the insertion resistance,the excavation resistance and the work of the hydraulic cylinder are obtained.Load.(2)Analyze the working principle of the hydraulic system of the excavating loader,and design the electro-hydraulic proportional control system of the loading working device according to the changing characteristics of the load during the loading process and the actual working conditions.Based on the bond graph theory,the model of the hydraulic system of the boom is established and the lifting is derived.The equation of state of the working condition;based on this,the mathematical model of the lifting condition is established based on MATLAB/Simulink and the influence of the volume,damping coefficient,flow rate and spring stiffness of the valve end face of the reversing valve on the dynamic characteristics of the reversing valve is further analyzed.(3)According to the above design scheme,the mathematical model of the boom control system is established.The fuzzy control principle is analyzed and the fuzzy PID controller of the boom control system is designed.The traditional PID controller and fuzzy PID controller are used to simulate the system.The results show that: The cylinder displacement response speed under PID control is fast,the time to reach the steady state is short,and the control effect is better.(4)Based on ADAMS,AMESim and MATLAB/Simulink to build an electromechanical and hydraulic integrated simulation environment,on this basis,the electromechanical and hydraulic joint simulation model of the excavator loader working device is established;the working process of the simulated working device under no-load and fixed load conditions is simulated.The simulation results show that the effect of the hydraulic cylinder displacement under the fuzzy PID control is fast,which verifies the feasibility of the above design scheme.Under the fixed load,the fuzzy PID control hydraulic pressure The cylinder displacement error is only 0.89%,and good control results are obtained.