Theoretical and experimental investigation of stratified robotic finger gaiting and manipulation

Many interesting control systems are characterized by the fact that the motion equations describing such systems are discontinuous. These kinds of discontinuous motion equations may arise in many ways, and an important subsets of such problems arise when constraints on the system are intermittent. For example, for a multifingered robot hand to manipulate an object, its fingers make contact with the object intermittently, which results in discontinues constraints to the system. Or for a biped robot to walk, its feet make contact with the ground cyclically. Due to the discontinuous nature of such systems, traditional linear and nonlinear control methods are inapplicable.; This dissertation presents the experimental verification of a previously presented general method to control and plan motions for such systems and the extension of the method to the cases when the surface of the object or the locomotion terrain is non-smooth. Camera-space manipulation is also incorporated in the experiments to obtain updated information about the pose of the object to improve the precision and robustness of the experimental work. Two problems associated with the application of the camera-space manipulation method to the experiments are addressed: one is the localization of three-dimensional object based on the information of the visual features attached to the object and the other is to calibrate the kinematics model of multiple robots as well as their relative coordinate relationships with computer vision. Results show that the general method for control and motion planning for stratified system is independent of the shape of both the object and the finger tips, the number of fingers as well as the finger kinematics. The implementation of the camera-space manipulation method to the experiments improves the precision and robustness of the experiment. The extension of the general method to non-smooth stratified manipulation works with smooth fingers to manipulate non-smooth objects.