Abstract: Nonlinear control method is provided for a closed-loop trajectory in a control system of the form x=.function.(x)+u through a sliding surface, s, chosen such that s=e+.lambda.e=, where e is the trajectory, and .lambda. is a positive constant using a control law of the form ##EQU1## which exploits terminal attractors of the form ##EQU2## where .alpha. is a constant greater than zero, .beta..sub.n, .beta..sub.d =(2i+1), where i belongs to the set of positive integers chosen for .beta..sub.n and .beta..sub.d, and .beta..sub.d >.beta..sub.n for convergence in finite time. For a system in which an initial S.sub.i is zero, a control law is used of the form ##EQU3## which yields a control equation ##EQU4## where .delta..sub.n, .delta..sub.d =(2i+1), wherein i belongs to the set of positive integers chosen for .delta..sub.n and .delta..sub.d, and .delta..sub.d >.delta..sub.n for retaining convergence in finite time.

Abstract: A shared system for robot control including integration of the human and autonomous input modalities for an improved control.Autonomously planned motion trajectories are modified by a teleoperator to track unmodelled target motions, while nominal teleoperator motions are modified through compliance to accommodate geometric errors autonomously in the latter. A hierarchical shared system intelligently shares control over a remote robot between the autonomous and teleoperative portions of an overall control system. Architecture is hierarchical, and consists of two levels. The top level represents the task level, while the bottom, the execution level.In space applications, the performance of pure teleoperation systems depend significantly on the communication time delays between the local and the remote sites. Selection/mixing matrices are provided with entries which relfect how each input's signals modality is weighted.