Grasping force optimization for dual-arm space robot after capturing target based on task compatibility

Abstract

Grasping force optimization (GFO) is a crucial step in multi-arm manipulation tasks, aiming to suitably distribute the external force applied on the target to manipulators. The problem has not been applied to the field of space robot, which is more complex than ground mechanisms due to the dynamic coupling effect and multiple constraints. This paper presents the GFO method for the dual-arm space robot after capturing target. The problem is formulated as a convex optimization problem, which considers the friction constraints and generalized input constraints synthetically. The input constraints are derived for the space robotic system which contain both kinematic and dynamic characteristics. In order to reduce the dimension of the problem, a convenient method based on the concept of task compatibility is proposed to obtain the initial value and decouple the input constraints from the optimization problem. Meanwhile, the line search method based on eigenvalue analysis is adopted to determine the step size. Finally, simulation results are presented to show the effectiveness of the proposed method for different target motion.