Robotic Manipulation Using High Bandwidth Force and Vision Feedback

High bandwidth sensor feedback is necessary for pegorming precise manipulation tasks within imprecisely calibrated and dynamically varying environments. Force controlled manipulation is a common technique for compliantly contacting and manipulating uncertain environments. visual servoing is an eflective technique for guiding imprecisely calibrated manipulators with imprecisely calibrated camera-lens systems. These two types of manipulator feedback, force and vision, represent complementary sensing modalities: visual feedback provides information over a relatively large area of the workspace without requiring contact with the environment, and force feedback provides highly localized and precise information upon contact. This paper presents three different strategies which combine force and vision within the feedback loop of a manipulator; traded control; hybrid control; and shared control. These strategies can be used alone, or in concert with each other, depending on the manipulation task. A discussion of the types of tasks that beneJit from the strategies is included, as well as experimental results which show that the use of visual servoing to stably guide a manipulator simplij5e.s the force control problem by allowing low gain force control with relatively large stability margins. Submitted to Mathematical and Computer Modelling An International Journal /? 7s I