Dual-arm supervisory and shared control task description and execution

Abstract

A unified control method for description and execution of cooperative dual-arm telerobotic supervisory and shared control tasks with multiple sensory inputs is presented. A general task execution primitive provides the capability. The desired behavior of execution is described by a large input parameter set to the primitive. The method provides a wide range of capabilities within the projected constraints for near-term space telerobotics systems such as limited computational power and safety. Move-squeeze decomposition is utilized to decompose forces sensed at the wrists of the two manipulators into forces in the move subspace, which cause system motion, and forces in the squeeze subspaces, which cause internal forces. The move and squeeze forces are then separately controlled. Each sensor control source is provided with its own task space for control before merging the inputs in a common move space frame. Bounded behavior control is used to ensure execution within safety bounds as specified a priori to task execution. Several space servicing tasks utilizing the cooperative dual-arm control capability are described and experimental results from the tasks are given. The supervisory and shared control tasks include capture of a rotating satellite, orbital replacement unit changeout, fluid coupler seating and locking, and contour following.