Research On The Electro-hydraulic Proportional Control System Of Parallel-driven Spinning Manipulator

With the development of aerospace industry,the launch vehicle is making progress in large-scale and heavy duty,which has put forward higher requirements for its parts processing.Large thin-walled parts produced by the integrated spinning method have good mechanical properties making spinning integrated processing the mainstream method for the fuel tank bottom processing.In order to meet the requirement of a large spinning force for the spinning processing mechanism,a parallel spinning manipulator structure driven by 4 hydraulic cylinders is proposed then the kinematics and dynamics modeling and simulation of the parallel structure are completed.In view of the nonlinearity disturbance in the system,a fuzzy adaptive sliding mode control algorithm is proposed and the simulation results completed by Matlab show the fuzzy adaptive sliding mode control algorithm has a better control effect than the traditional control methods.Finally,the control system construction and software development are completed for future experiments.The main research work in this paper is shown in below:(1)According to the processing requirements in the spinning process,the structural design of the parallel manipulator,the hydraulic system circuit design and the control system frame design were completed;also the key components of the system were selected.(2)The kinematics inverse solution of the parallel manipulator is obtained by the coordinate transformation method.And the BP neural network is trained to represent the positive kinematics model of the parallel manipulator.Besides the static and dynamic models of the parallel manipulator can be obtained by the principle of virtual work.In order to ensuring the correctness of the kinematics and dynamics models,ADAMS is combined with Matlab to achieve the simulation.(3)The mathematical model of the valve-controlled hydraulic cylinder system is obtained through three common equations in electro-hydraulic system control namely the load flow equation,the flow continuity equation and the force balance equation.And the physical model is built by Hydraulics module in Matlab to achieve comparison with the mathematical model.(4)Four algorithms are designed for the valve-controlled hydraulic cylinder system namely PID,SMC,BSMC and FSMC.And Matlab is used to realize the tracking simulation of four control algorithms on sinusoidal signals which can show the control performance comparison.(5)Segmented SMC is proposed based on the motion and load characteristics of the parallel manipulator.Spinning simulation is realized by Matlab,whose results show that the segmented FSMC has a good control effect in the entire parallel manipulator processing process.(6)The hardware construction,the software development,the port signal debugging of the control system ant the motion control experiment of single valve controlled hydraulic cylinder system are completed for future parallel manipulator control experiments.In summary,the structural design,kinematics analysis,dynamics analysis,motion control algorithm design with simulation,hardware construction,hardware development of the parallel-spinning manipulator and preliminary debugging of experimental platformare are completed in this article,which prepares for future experiments.The research on parallel spinning manipulators will help to make up for the technical shortcomings of China's large-scale thin-wall spinning processing and contribute to the development of China's launch vehicle.