Research On Control Of The Three Degrees Of Freedom Parallel Motion Simulation Platform

What the paper studies is a three degrees of freedom motion platform, it is a kind ofspatial parallel mechanism. Comparaed with the serial mechanism, it has simplemechanical structure, large capacity and high performance to price ratio, it has been paidmore and more attention in mechanism research, in the field of simulation it also has agood application value. This simulation platform can be sued for recreation facilities tomake the palyers feel true driving pleasure, enrich people’s leisure life more exciting, suchas entertainment horse racing and4D theater seats, etc.This paper based on the structure of three degrees of freedom parallel mechanism,combined with the requirements of the performance index of the motion platform, themechanical structure and kinematic, dynamics are analyzed, the simulation platformcomponents selection and the control method of the system are determined.Firstly,through the comparison and optimization of structure,the structure of3-DOFparallel motion simulation platform is determined. The main supporting part of thisplatform is composed by three collapsible electric cylinder rods, this platform achieves aspecific position and orientation with one translational and two rotional by flexing thescrew in electric cylinder. Secondly,based on the platform of the mechanical structure, thekinematics equations were obtained through the space coordinate transformation. We getthe position parameters of the platform after solving the kinematics equations. Thedynamic model was established based on Lagrange’s equation, using MATLAB to simulatethe trajectories of the platform, the relation between drive force and system parameters wasanalyzed, verified the feasibility of the mechanical structure.Finally, based on the communication function between PC and PMAC motion controlcard, using PMAC programming software write control program, complete simulationplatform of movement function. The control section is an important part of the entiresystem, software is the key to realize the control strategy. With PMAC motion control cardis flexible and practical, it is used in various places in today’s industrial automation. Themotion control system with PMAC can take advantage of the processing power of thecomputer, enhance the execution speed of the program. With the research and development of the parallel mechanism, the platform will be morebroad application.