Application of the Obstacle Vector Field Method for Trajectory Planning of a Planar Manipulator in Simulated Microgravity

Capture and removal of large space debris is needed to prevent the growth of the debris population in low Earth orbit. Capture of a non-cooperative object by a manipulator mounted on a chaser satellite requires collision-free trajectory of the manipulator. The obstacle vector field (OVF) method allows to solve the trajectory planning problem in difficult scenarios. The OVF method is based on a vector field that surrounds the obstacles and generates virtual forces that drive the manipulator around the obstacles. The original formulation of the OVF method allows to obtain the desired position of the gripper, but not the desired orientation. To perform the grasping manoeuvre, the gripper has to be positioned in a specific point and aligned with the grasping interface. In this paper, we propose a modification to the OVF method that allows to obtain the desired position and orientation of the gripper. Moreover, we investigate the practical applicability of the OVF method. The OVF method is demonstrated in experiments performed on a planar air-bearing microgravity simulator. The presented results prove that the OVF method can be applied for a real system operating in simulated microgravity conditions.