Robust trajectory design for object throwing based on sensitivity for model uncertainties

Abstract

Throwing an object by a powered robot system is of great importance in unmanned environments. In this paper, we consider the problem of throwing a point-mass object to minimize uncertainty in the object's landing position, given uncertainty in (1) the robot's initial configuration and (2) friction at the joints. Our analysis assumes that the robot's throw is executed using open-loop torque commands, and it relies on the linearized sensitivities of (a) landing location with respect to release state, (b) release state with respect to initial robot configuration and (c) joint friction. Moreover, the effectiveness of the proposed method is evaluated by Monte-Carlo simulations.