“…It is very important for robot manipulators to avoid collisions with obstacles; otherwise, the robot manipulators or the objects being held may undergo serious damage. In addition, collision avoidance is a fundamental problem for the redundant robot manipulators (Aitkenhead & McDonald, 2002;Cheng, Lu, & Sun, 1998;Ding & Chan, 1996;Saravanan, Ramabalan, & Balamurugan, 2009;Wang & Xin, 2013;Zhang & Wang, 2004). It is about how to avoid obstacles cluttered in an environment while performing primary tasks at the end-effector.…”