Optimal Design And Dynamics Study Of 4-DOF Hybrid Robot

In this research,4-degrees of freedom(DOF)hybrid robot can be divided into a planar 2-DOF redundantly actuated parallel mechanism and a 2-DOF series mechanism.Aiming at the task of grasping and placing regular object,this paper focuses on the design and optimization of the planar 2-DOF redundantly actuated parallel mechanism and the dynamic modeling of the 4-DOF hybrid robot,control strategy and experiment.The main researches are as follows:Kinematic analysis and size optimization of the 4-DOF hybrid robot are carried on.Firstly,the kinematic inverse solution of the planar 2-DOF redundantly actuated parallel mechanism and the 2-DOF series mechanism are respectively solved.Secondly,considering the velocity ellipsoid,the stiffness ellipsoid and the performance evaluation index of the effective working space,the size optimization of the parallel mechanism is performed by the combination of the performance atlas superposition method and the multi object normalization method.Thirdly,based on the dimension of the parallel mechanism,the singularity is analyzed.Global dynamic model of multi energy domain of the hybrid robot is built,including the domain of mechanism,electricity and air.Firstly,the dynamic model of driving motor and pneumatic part are established by using the traditional bond graph theory.Secondly,the dynamic model of the planar 2-DOF redundantly actuated parallel mechanism and the 2-DOF series mechanism is established by using the screw bond graph theory.Thirdly,the driving torque optimization of the planar 2-DOF redundantly actuated parallel mechanism is presented,and the dynamic solution of the hybrid robot is solved by using the state equation derived from the bond graph model.The screw bond graph model of the whole hybrid robot is built by the bond graph simulation software 20-sim.Firstly,the parameters of servo motor are set up.Secondly,two methods are used to control the planar 2-DOF redundantly actuated parallel mechanism,which are the redundant driving branch follower and force hybrid with position control.The experimental system is set up,as the controller and driving device using Beckhoff controller and servo motor,servo drive in the redundant branch and force hybrid with position control under the two conditions of the hybrid robot control experiment.Based on the experiment of grasping and placing objects with end effector,this paper studies the ability of the 4-DOF hybrid robot to complete the task.