Path feasibility and modification based on robot workspace geometry

The workspaces of robot manipulators consisting of different combinations of joint types with offsets in between are analyzed. The analysis concentrates on nonredundant wrist-partitioned types of robot manipulators. Kinematic feasibility of a planned robot path is restrained by the kinematic constraints of the robot executing the task, such as workspace, configuration, and singularity. Since the kinematic constraints can be described utilizing the geometry of the given robot, corresponding regions within the robot workspace can be expressed in a geometrical representation. Consequently, geometric information can be extracted from the tested path and the geometric boundaries of these regions. Then, by utilizing the geometric information and proper modification strategies, a Cartesian robot path that is kinematically infeasible can be modified according to different task requirements. To demonstrate the proposed path feasibility and modification schemes, simulations for a 6R robot manipulator are presented