Development of virtual link method for the solution of hyper-redundant spatial robots

This article presents a new method for the kinematics of hyper-redundant spatial robots, called the virtual link method. The method is based on dividing the robot into sub-systems consisting of three or four links. Virtual links are established between the first and the last nodes of each sub-system. A hypothetical robot with reduced of degrees of freedom is developed using the virtual links. The method then solves for the kinematics of the virtual link system followed by the sub-systems. The virtual link method also provides a singularity-free solution by predicting their occurrence and taking appropriate action. An approaching singularity is reflected by a drop in the determinant of the Jacobian of the system below a threshold value. In this situation, the method either chooses a different virtual link configuration or switches to a displacement distribution scheme. (C) 1996 John Wiley & Sons, Inc.