Research On Robotic Assembly Theory Of Circular-rectangular Compound Peg In Hole

At present,industrial robots are widely used in the assembly of some simple geometric parts,such as circular peg-in-hole,rectanglular peg-in-hole.However,the research on the assembly of complex geometry parts(such as round keys,splines,circular shaft with key,etc.)and irregular shaped peg and hole parts has not been carried out in-depth.Therefore,in order to promote the application of automatic assembly technology of industrial robot for complex peg and hole parts,this paper creatively carried out the research on the robot assembly theory of circularrectanglular compound peg-in-hole assembly,which provides important theoretical guidance and practical application value for the further development of robot assembly.In this paper,the robot assembly theory of circular-rectangular compound pegin-hole with clearance is deeply studied,and combined with modular manipulator,impedance control to realize assembly.Because of the diversity of circularrectanglular compound peg and hole parts,it is impossible to carry out research on every parts.However,due to their similar geometrical shapes,one of them,i.e.a compound part consisting with a cylinder and a rectangle column,has been developed,the derived theory is also applicable to other types of circular-rectangular compound peg and hole parts.To this end,the main research content of this paper is divided into following parts:Firstly,for one type of circular-rectanglular compound peg and hole parts,the possible contact states in two-dimensional and three-dimensional are deduced.Each contact state is summarized according to the number of contact points,and the force analysis is carried out according to the characteristics of each contact state.The force/moment relationship expressions of each contact state are derived.Secondly,according to the force/moment relationship of each contact state,the jamming diagram is drawn in two directions in two dimensions,and the conditions to avoid jamming are deduced according to the jamming diagrams,which lays the foundation for the smooth implementation of assembly.Thirdly,the assembly strategy of compound parts is studied,including hole searching and pose adjustment strategy during assembly.The controller is built by combining the impedance control in force control,and the influence of impedance parameters on control system is studied.Finally,in the simulation environment,a circular-rectangular compound peg and hole parts are selected to verify the jamming diagrams,and the assembly task in the simulation environment is realized combined with the assembly strategy above.The theory proposed in this paper provides a reference for industrial robot to realize complex shape parts assembly in automatic assembly task.