Herman Bruyninckx, PhD, 27 April 1995, Katholieke Universiteit Leuven, Dept. Mechanical Engineering, Celestijnenlaan 300B, B-3001 Heverlee Belgium

Kinematic Models for Robot Compliant Motion with Identification of Uncertainties

This thesis is about force controlled compliant robot motion, with the emphasis on: 1) modelling of arbitrary and time-varying contact situations between a rigid manipulated object and rigid objects in its environment, 2) motion specification in terms of allowed velocities and accelerations for the manipulated object, maintaining the contact with the physical constraints but without generating too large contact forces, and 3) on-line identification of uncertainties in the instantaneous geometric parameters of the motion constraint model, i.e., the position of the contact points, the direction of the contact normal, and the local curvature parameters. Requirements for generality, simplicity and robustness have guided the research work. The main new theoretical results of this thesis are: 1) the successful use of the kinematics of mechanisms as the unifying framework for the integration of modelling, specification and identification; 2) the use of the first and second order geometric parameters of the contacting surfaces of the manipulated object and its environment as basic model parameters; 3) the derivation of identification equations for uncertainties in these parameters, based on the general physical properties of consistency and reciprocity; and 4) new symbolical algorithms to calculate the derivative of the Jacobian matrix of a kinematic chain with respect to one of the chain's joint angles. Real-world application of these theoretical results has been proven feasible by various experiments on a commercial robot arm equipped with force control software of moderate complexity.