Research on elastic deformation modeling of collaborative robots

Abstract

To improve the positioning accuracy of collaborative robots, an elastic deformation modeling method of manipulator robots is proposed in this paper. This approach is able to consider flexibility of robot modules comprehensively, and can compensate the elastic deformation caused by external wrenches and the deadweight of the robot in addition to possessing advantages of low computational complexity, easy modification as well as high real-time. Firstly, stiffness matrices of each robot module with 36 degrees of freedom (DOFs) are obtained by using the finite element analysis. Then, the kinematic model of a robot is established which is adapted to stiffness modeling of robot modules, and the force condition can be achieved by the robot statics analysis with the deadweight in order to acquire the elastic deformation of module units, which will be used to compensate the positioning error resulted from manipulator compliance. Furthermore, the elastic deformation model is built by the differential transformation method, and can be used to compensate the positioning error. Lastly, the finite element simulation is carried out, and results of the simulation show the proposed modeling method is effective.