An Automated Reactive Approach to Single Robot Exogeneous Planar Assembly

In this paper, we are concerned with the automation of single robot exogeneous assembly in simple planar settings. Here, a set of of unactuated disk-shaped parts needs to be serviced by a single robot that resides outside the workspace and is capable of moving the parts one at a time through sliding or lifting slightly. The task is to have the parts end up in their respective goal positions without any collisions whilst moving. We present an automated reactive approach through the composition of one-part movements. The movement of each part is achieved by a controller obtained through the projection of a carefully constructed vector field on the respective configuration subspace. Such a scheme is known to accommodate positional variations naturally. Once the movement terminates, the robot chooses the next part to move in a cyclic manner. The contribution of this paper is to show for the first time that with certain restrictions on the allowed goal configurations, the assembly task is either successfully completed or terminated (rather than useless cycling of a part or from part to part) while the generated sequence of motions never causes collisions among the parts.