Path generation and control of humanoid robots during extravehicular activities

This paper proposes and investigates strategies that can be used to plan the motion and control of humanoid robots in some elementary tasks that characterize extravehicular activities. The humanoid robot taken into account is a torso with two arms and two grippers at their extremities. This study addresses the problem of robot motion on the complex system of handrails and handles that characterize the International Space Station. Such a complex task has been divided into two elementary sub-tasks: motion planning and tracking the planned trajectories. First, an optimization procedure is presented to plan and coordinate the robot's arms motions and graspers to achieve the desired location using handrails. Then, a low-level controller is used to guarantee that the robots' actuators can follow these previously generated trajectories. Simulation results assess the applicability of the proposed strategy in different typical operations that potentially can be performed in an extravehicular activity scenario.