Design And Research Of Electro-hydraulic Servo System Of Mill Relining Plate Manipulator

With the rapid rise of computer technology and the continuous improvement of intelligence level,the application of artificial intelligence in the field of robotics has gained higher attention.Heavy-duty manipulator has the advantages of flexible movement,simple operation,safety and stability,and high work efficiency.It is used in mining,metallurgy,aerospace and other fields,and has become an important equipment in the industrial field.In this paper,the 7-DOF heavy-duty manipulator for relining plate of mill was taken as the research object,and the hydraulic system driving the manipulator was designed and studied to meet the requirements of the end precision and load clamping of the manipulator.The main research contents of this paper are as follows:(1)The structure of the manipulator was analyzed,and the basic working conditions and performance requirements of the manipulator were clarified.By analyzing the hydraulic system scheme of the manipulator,the basic hydraulic circuit was selected,and the schematic diagram of the electro-hydraulic servo system was drawn up.The main technical parameters of the hydraulic system were calculated,and the models of the main components in the system were selected.The parameters and layout of the hydraulic pump station were determined.(2)Taking the valve-controlled motor as the research object,the mathematical model of the electro-hydraulic servo system of the valve-controlled motor was established based on the transfer function method.The dynamic performance of the system was simulated by using Matlab/Simulink.The results show that the system is stable,but its response speed is slow and the control accuracy is poor.The system must be corrected.(3)Considering the non-linearity,time-varying parameters and non-linear external interference of the system and other factors,a more accurate non-linear model of the system was established by using the state space method,and the adaptive robust integral of controller was designed.To compensate for the effects of external disturbances and unmodeled dynamics in the system,a control strategy combining the finite-time disturbance observer with the adaptive robust integral controller of was further studied.The stability of the system was analyzed by Lyapunov law,and the control effects of the two controllers were verified by simulation in Matlab.The results show that the observer has a good observing ability for different disturbance signals,and the effectiveness and feasibility of the proposed control strategy are verified.(4)According to the system design and actual working conditions,experiments were carried out on the prototype of the manipulator.The experimental schemes of single joint control and whole manipulator motion control were designed.The experimental results show that the control strategy studied can meet the accuracy requirement of 0.01° for a single joint,and the tracking accuracy of the manipulator under the conditions of no-load and load of 2500 kg can reach the end-point accuracy requirement of 0.4 mm.