The Kinematic Analysis And Optimization Of A3-DOF Automatic Drilling And Riveting Mechanism

In the field of the automatic drilling and riveting technology, it is a difficult work to rivete on a large dimension thin-wall workpiece. In order to solve this problem, a3-RPS parallel mechanism is put forward. The kinematics property of the3-RPS parallel mechanism is perfectly meet the requirement of the automatic drilling and riveting processing. Also it has many advantages, such as simple structure, good maneuverability, large workspace and so on. This paper focuses on3-RPS parallel mechanism which can be used as the basic part of the automatic drilling and riveting equipment, and studied the geometric parameter optimization of this mechanism based on it’s kinematic analyses.Firstly, the degree of freedom of the3-RPS parallel mechanism was studied by using the screw theory. A T&T euler anger was used to describe the orientation of the moving platform and build the forward/inverse position solution model. The first and second order influence coefficient matrixes were obtained based on the influence coefficient method of screw theory.Secondly, based on the inverse kinematics analysis, the orientation workspace and the position workspace of the3-RPS parallel mechanism were obtained by searching the boundary of the possible work area constrained of serious conditions. Furthermore, the effects of the main parameters on the workspace of the mechanism were analyzed. The singularity distribution was also studied.Thirdly, an index was introduced to evaluate the effectiveness of the motion/force transmissibility of the3-RPS mechanism to analyze it’s orientation adjustment capability. Then a performance atlas was worked out based on the Design Methodology to optimize the geometric parameters of the mechanism for the purpose of good orientation ability and motion/force transmissibility.Finally, A movement simulation for a typical motion of the automatic drilling and riveting machine was carried out using the software ADAMS. By comparing the force situation of3-RPS parallel mechanism before optimization and optimized, the effectiveness of the geometric parameter optimization was verified as well.