Flexible planetary gear drives in robotics

A method of modeling and computation of industrial robots with rigid-link flexible joints actuated by flexible planetary gear drives is presented. Joint flexibility, as a predominant source of resource, often results in inaccurate tracking of prescribed robot trajectories. The authors consider an n-link industrial robot modeled by rigid-body linkage members interconnected by flexible joints, actuated by DC servomotors and a flexible planetary gear system. The single-link joint model with one flexible planetary gear unit has six degrees of freedom (DOFs). In the gears the periodical time-dependent tooth stiffness represents an essential excitation source and was incorporated into a dynamic model of a robot system. The dynamic model of the robot with flexible joints for the case of elastic planetary gear is presented on example of the SCARA robot's basic configuration for two DOFs.<<ETX>>