DEVELOPMENT OF VIRTUAL LINK METHOD FOR THE SOLUTION OF HYPER-REDUNDANT SPATIAL ROBOTS

This article presents a new method for the kinematics of hyper-redunda nt spatial robots, called the virtual link method. The method is based on dividing the robot into sub-systems consisting of three or four li nks. Virtual links are established between the first and the last node s of each sub-system. A hypothetical robot with reduced of degrees of freedom is developed using the virtual links. The method then solves f or the kinematics of the virtual link system followed by the sub-syste ms. The virtual link method also provides a singularity-free solution by predicting their occurrence and taking appropriate action. An appro aching singularity is reflected by a drop in the determinant of the Ja cobian of the system below a threshold value. In this situation, the m ethod either chooses a different virtual link configuration or switche s to a displacement distribution scheme. (C) 1996 John Wiley & Sons, I nc.