Determining the initial configuration of uninterrupted redundant manipulator trajectories in a manufacturing environment

In a manufacturing environment where a redundant manipulator is programmed to follow a specific trajectory such as welding painting and soldering it is often the case that the manipulator reaches a singular configuration where the program is stopped the manipulator has to be switched to a new configuration and the motion continued This paper presents a method of determining the initial configuration of robotic manipulators to traverse a path trajectory without halting the motion The method consists of (1) identifying singular curves/surfaces using the Jacobian rank deficiency method (2) determining non-crossable curves/surfaces using acceleration-based crossability criteria (3) finding if the path intersects any non-crossable singular curve/surface If there is not any intersection the manipulator does not interrupt with any initial configuration on the trajectory Otherwise the intersection is determined and the non-crossable singular configuration at the intersection point is determined (4) solving the differential algebraic system of equations (DAE) of index 2 using the Runge-Kutta method and (5) solving the optimization problem The method is illustrated through examples (C) 2010 Elsevier Ltd All rights reserved