Design And Simulation Of Parallel Configurations White Body Positioner

In this paper, a kind of3-UPU-UPU parallel positioning mechanism is designedaccording to the application requirements of BIW conveyor system, a four pointssupport BIW conveyor system is proposed based on the parallel positioning mechanism,and the car body positioning reprint is realized in different processing sites. A seriesof research is launched on the parallel mechanism: the configuration synthesis andkinematics analysis are completed, the mechanism is optimized after kinematicsperformance indexes are established, dynamic model is built, the control system isdesigned, and the joint simulation of the body in white flexible conveying system isresearched etc. The main contents are as follows:(1) Configuration design of parallel conveying positioning mechanism. Demandfreedom of the mechanism is determined from the point of the motion characteristicsand functional requirements for the white vehicle body flexible conveying system; the3-UPU-UPU parallel mechanism is selected as the main positioning supporter throughthe constraint synthesis method based on screw theory.(2) Scale synthesis and kinematics performance analysis of parallel conveyingpositioning mechanism. The kinematics is analyzed and optimization design iscompleted for the3-UPU-UPU parallel mechanism: the inverse solution of theposition and the Jacobian matrix are solved, the flow of workspace search andkinematics performance evaluation indexes are established, the workspace feasiblepoints, global condition number as well as the global maximum carrying capacity areselected as the optimizing indexes, the radius of down and up platform, the maximumlength and minimum length of branched chains are took as the optimization parameters,the3-UPU-UPU parallel mechanism is optimized by using the weighted sum algorithm.(3) Dynamics analysis of parallel conveying positioning mechanism based onSimMechanics. The “S curve accelerate and decelerate” programming algorithm is usedin planning the movement for the moving platform reference point,and PID controllersare applied to control simulation of the3-UPU-UPU parallel mechanism dynamicmodel based on SimMechanics.(4) Joint simulation of four points positioning support BIW flexible conveyorsystem. The united simulation model is established based on Matlab and RecurDyn, combine the advantages between the two software, then the simulation of the whitebody flexible conveying system is carried when it works, obtain the movement of eachparallel positioning mechanism, and the feasibility of the system is verified at the sametime.Research shows that it can complete the various car body positioning reprintbetween different processing sites by using the BIW flexible conveyor system based on3-UPU-UPU parallel mechanism which is proposed in this paper, has importantresearch significance and application value.