A Trajectory Planning for a 3-RRR manipulator to remove Backlash in Actuating Joints

Trajectory planning has always been of great significance to researchers for the pivotal role it plays in reaching the goal for a manipulator which is to pass a track as smooth as possible. Another important factor to practically implement a robot is its behavior in joint from kinematic points of view. A designer of a manipulator is expected to give full consideration to the behavior of both joint coordination and workspace equally. A trajectory planning might be implemented on a manipulator and it could successfully be able to pass a track defined but its actuators in some points would possess reversals which is of great importance. In this article, an S-Curve Trajectory Planning is executed on a 3-RRR manipulator and the drawback of this method due to the reversal in the joint coordination will be shown. Finally, a method for a 3-RRR manipulator is proposed to pass a path in the workspace and its joints are guaranteed to avoid any reversals throughout the motion.