Time-minimum Motion Planning For Parallel Manipulators

Parallel robots have been mainly applied in the field of industrial high-speedpick and place. Because it has high capacity, stiff structure, simple solution ofinverse kinematics, high precision and speed, and many other advantages. Thepoints of parallel mechanism’s workspace are not all isotropic. So time-minimummotion planning approach based on line trajectory can’t completely express parallelrobot’s high-speed characteristics. In order to improve parallel robot’s industrialproductivity, a better time-minimum motion planning approach must be needed.The main researching object of the dissertation is Delta robot. The main workis focused on solving the key technical issue which is about time-minimum motionplanning. Delta robot’s mechanism is analyzed. The solution of Delta robot forwardand inverse kinematics is worked out with the use of the geometric method. Theprinciple of virtual work is used to solve dynamic equations. Based on that, a newconcept of integrated dexterity is proposed by the way of calculating robot’sdexterity index and dynamic manipulation. Distribution principle of the values ofintegrated dexterity in the workspace of Delta robot was researched. Takingadvantage of the distribution of the values of integrated dexterity in the workspaceof Delta robot, the trajectory could be planned between the two arbitrary points.Time-minimum velocity plan is made based on Pontryagin principle. Comparing tothe conventional trajectory plan, the validity and superiority of the trajectory isverified.In this dissertation, Delta robot experimental platform is applied to makesimulation about the researched motion planning algorithm. It can verify the validityof the motion planning algorithm. The obtained experimental datum and conclusionsbasically achieve the objectives of the research.