Motion Control And Research On Six Degree Of Freedom Parallel Robot

The parallel mechanism is a new structure with respect to the series mechanism.Its advantage lies in its high rigidity,very high accuracy,strong carrying capacity,easy control and so on.In terms of structure and performance,the parallel mechanism and the tandem mechanism are dual relations.In the application,the parallel mechanism and the series mechanism are complementary relationship.These features greatly expand the scope of application of the robot.Parallel mechanism is a complex system.which has the characteristics of high degree of freedom,multi-input and multi-output,high degree of nonlinearity,many parameters and strong coupling.There are many problems still need further research and improvement.In this paper,the kinematics analysis of the six degrees of freedom(6-DOF)parallel mechanism is introduced in detail,that is,the positive and negative solutions of the position of the parallel mechanism are calculated.And the paper analyzes the speed and acceleration of platform motion.Firstly,a large number of input and output data sets are obtained by using the position inverse solution.These data sets are used as extreme training machines for network training samples.Secondly,Extreme learning machine algorithm can be used to solve the positive solution of position.The input displacement and the output position of the parallel mechanism are nonlinear.Then the output position corresponding to the input displacement is solved.Finally,the method is simulated by Matlab software.On the basis of kinematics analysis,the Newton-Euler method is used to establish the dynamic model for the parallel mechanism.In Matlab/SimMechanics,the mechanical model of the Stewart platform was established.The mechanical model is tightly integrated with Simulink.The parallel mechanism simulation control system is constructed.Trajectory planning is performed on the upper platform of the parallel mechanism.And the overall scheme of the six-DOF parallel mechanism control system is designed.Based on the proportional derivative(PD)controller,robust adaptive control strategy is adopted.The robust adaptive PD control algorithm is applied to Stewart parallel robot single cylinder servo system.In the Matlab / Simulink module,the parallel mechanism joint control system is established.The robust adaptive PD control algorithm is applied to the motion control and the simulation experiment is carried out.