I. Introduction
Collision-free motion planning is a classical problem in robotics. For instance, in a human-robot cooperative system, the robot must stay free of pedestrians. This problem can be formulated as an optimization problem for computing the collision-free path for the robot in environments, which contain other static and/or moving obstacles. In this direction, the robot is commanded by the pre-computed control input in each cycle based on environmental information and its desired target pose. Instead of a fixed path, the collision-free motion planning algorithm would compute a path that progresses towards the target as well as avoids collisions with obstacles.