Failure-tolerant path planning for the PA-10 robot operating amongst obstacles

This work considers kinematic failure tolerance when obstacles are present hi the environment. An example is given using a fully spatial redundant robot, the seven degree-of-freedom Mitsubishi PA-10. This article addresses the issue of finding a collision-free path such that a redundant robot can successfully move from a start to a goal position and/or orientation in the workspace despite any single locked-joint failure at any time. An algorithm is presented that searches for a continuous obstacle-free monotonic surface in the configuration space that guarantees the existence of a solution. The method discussed is based on the following assumptions: a robot is redundant relative to its task, only a single locked-joint failure occurs at any given time, the robot is capable of detecting a joint failure and immediately locks the failed joint, and the environment is static and known.