Research On Hybird Force/Position Controlalgorithm Of 6PUS-UPU Parallel Robot With Actuation Redundancy

Recently, parallel robot has become one of the research hotspots in robot field. Forthe reason of uncertainty, nonlinearity, and complex control etc, the control precision andreal time performance are still needed to be improved. Intelligent control is a burgeoningsubject and has become the higher stage of the control field. Combination of both isconducive to improve the control performance.PM(Parallel Mechanism)is provided with high stiffness, high precision and heavyload capacity etc. At the same time, however, for the reasons of certain constructionfeatures, it possesses some drawbacks, such as singular configurations in workspace,comparatively smaller workspace, and inflexibility of the end of the manipulator etc.Redundant auction could reduce or even clear singular configurations, extend effectiveworkspace, increase the stiffness, optimize the driving force, balance the inner force andimprove the motion precision. In this paper,a new kind of 6PUS-UPU redundant auctionparallel manipulator is introduced, and a certain amount of study has been conducted. Themain research is as follow:Firstly, the structure of the 6PUS-UPU parallel robot is analyzed, the mainparameters are ascertained, the UPU branch is briefly analyzed and the dynamic model isgot based on KANE method. Then the driving forces are optimized by using the leastsquare method, and the driving force of the redundant branch is solved. The researchprovides theory foundation for improving the driving forces of the other branches.Secondly, the control theory of the parallel robot is researched. A new kind offorce/position hybrid control structure is proposed. The position serve system is built andthe order for the speed loop is reduced. Aiming at the features of the redundant branch, Idesign a fuzzy controller. Then co-simulation is realized by using MATLAB and ADAMS.Finally, disadvantages of normal position serve system are analyzed, and IMCcontroller is designed to improve the performance of serve system. As for the redundantbranch, the fractional order method is combined with fuzzy control to design a fuzzy PIbcontroller. Combination of both improves the control performance and differentialoperator is realized by using the modified Oustaloup filter.The theory in this paper lays a good foundation for the lucubrate and projectapplication of redundant auction parallel robot, and also provides some lessons for theoryresearch and application of the other parallel mechanism.