Research On The Spinning Machine Driven By 3-UPS-RCR Parallel Mechanism And Its Electro-hydraulic Control Systems

With the development trend of heavy load and large scale for launch vehicles,new requirements have been put forward for the processing of tank bottoms in rockets.Spinning process that can be used for the whole processing of thin-wall rotationally body becomes the ideal choice for the bottom processing.In view of the failure of wrinkles and buckling crack in the spinning processing,this paper presents a new type of super-large spinning machine equipment,composed of the blank holder device which can effectively solve the problem of wrinkles,the parallel mechanism driving the two-wheel feeding device,the tail clamping device,the mandrel drive system,the upper sliding platform system and other subsystems.Aiming at the problem of large load disturbance on 3-UPS-RCR 4 DOF parallel mechanism,a kind of sliding mode control algorithm with disturbance observer is designed,and an in-depth study about the parallel mechanism electro-hydraulic proportional position control systems is carried out.And main research work is present as follows:First of all,according to the requirement of the spinning process,spinning machine equipment is designed,including: the mechanical structural design of spinning machine and related parts selection and the design of hydraulic system.Then,in view of the the most important subsystem of spinning machineparallel driven spinning roller system,design 3-UPS-RCR 4 DOF parallel mechanism.The roller can move along the elliptic orbit,at the same time keeps vertical to the surface of mandrel.Forward and inverse kinematics analysis,as well as statics analysis are conduct.Considering large nonlinear disturbance in the working process,the mathematical model of electro-hydraulic proportional position control system with load disturbance is established,compared with the physical model established using SimHydraulics module to verify the rationality of the model.Moreover,a sliding model control strategy with disturbance observer is put forward.In Matlab/Simulink,the simulation model for the electro-hydraulic proportional position control system is established to study the tracking accuracy and robustness of the sliding model contrllor with DOB.On the basis of the single cylinder control,the inverse kinematics and forward kinematics analysis of the parallel mechanism,the simulation model of position and pose control for the spinning roller which is on moving platform of parallel mechanism driven by four hydraulic cylinders is established in the Matlab/Simulink.Considering the nonlinear load disturbance when the spinning roller works,the sliding model controller with disturbance observer for the position controller of parallel mechanism is designed.According to the simulation of the control systems,figure the four variables on behalf of the spatial position of the spinning roller.The simulation results show that the sliding mode controller designed based on the disturbance observer has good effect for the control of spinning roller's position and pose.At last,the hardware control system of the parallel spanning machine is designed and the control system software for spinning machine is completed.Experiments on single channel electro-hydraulic proportional valve control hydraulic cylinder system are carried on,and the results show that the sliding model controller with disturbance observer has a good performance on the control of the spinning roller's position.