Trajectory and control optimization for flexible space robots

This paper is concerned with a flexible space robot whose mission is to ferry some payload in space and to dock smoothly with an orbiting target. Using a perturbation approach, the problem is divided into one for the rigidbody maneuvering of the robot and one for the feedback control of elastic vibrations and perturbations from the rigid-body maneuvering motions. The procedure involves optimization of the robot trajectory, inverse dynamics for the determination of the maneuvering forces and torques, and the use of the linear quadratic regulator (LQR) theory for a time-varying system for the determination of an optimal control law for the elastic motions and the perturbation from the rigid-body maneuvering motions. A numerical example demonstrates the approach.