Singularity analysis of the Canadarm2

The determination of the singular or velocity-degenerate configurations of the Canadian Space Agency (CSA) Canadarm2 is presented. The Canadarm2 or space station remote manipulator system (SSRMS) is a 7-joint serial manipulator used on the International Space Station (ISS). A reciprocity-based based methodology for identifying 1-DOF (degree-of-freedom) loss singular configurations of joint-redundant manipulators is applied to a modified layout of the Canadarm2 (denoted modified Canadarm2). The modified Canadarm2 incorporates two additional link lengths not found in the Canadarm2. The results for the modified Canadarm2 are extended to the Canadarm2 by setting the two extra link lengths in the modified Canadarm2 to zero. It is shown that five sets of conditions defining families of singular configurations resulting in a single-motion DOF loss exist for manipulators having layouts kinematically equivalent to the Canadarm2 or modified Canadarm2. In addition, reciprocal screws characterizing the lost motion are found for each singular configuration.