Performing a 6-DOF robotic assembly task by using a static chain of 3-DOF C-spaces

This paper describes a method for changing contact states in a 6 degrees-of-freedom (DOF) assembly task, which consists of convex objects, by using a chain of 3-DOF C-spaces. In our method, a robot operator first decomposes the task into 3-DOF sub-tasks, programs a rough chain of the sub-tasks and gives the program to a robot system. The robot system interprets the program to the chain of 3-DOF C-spaces, switches the C-spaces according to the chain, and plans detailed contact-states transitions by using the C-space which corresponds to the sub-task. In the planning, 3-DOF C-spaces are used because they can be analytically generated or practically computed. We tested our method by simulating a peg-insertion task.