Passivity-based control methods for robots, which achieve the control objective by reshaping the robot system's natural energy via state feedback, have, from a practical point of view, some very attractive properties. However, the poor quality of velocity measurements may significantly deteriorate the control performance of these methods. In this paper we… (More)
In this note we propose a robust tracking controller for robots that requires only position measurements. The controller consists of two parts: a linear observer part that generates an estimated error state from the error on the joint position and a linear feedback part that utilizes this estimated state. It is shown that this computationally efficient… (More)
413 replacing the nonlinear load by a I 0 resistor. The dominant impulse response poles and residues of the circuit are then c a u l a t e d using AWE technique. For this circuit, two sets of poles and residues are required: from input to output and from a current source connected parallel to load to output. The first order response is then obtained using… (More)
In this note we propose a simple solution to the regulation problem of rigid robots based on the availability of only joint position measurements. The controller consists of two parts: (1) a gravitation compensation, (2) a linear dynamic first-order compensator. The gravitation compensation part can be chosen to be a function of either the actual joint… (More)
To establish empirical verification of a stabilizing controller for non-holo-nomic systems, the authors implement a hybrid control concept on a 2-DOF mobile robot. Practical issues of velocity control are also addressed through a velocity controller which transforms the mobile robot to a new system with linear and angular velocity inputs. Experiments in the… (More)
In the present paper we propose a globally convergent adaptive control scheme for robot motion control with the following features: First, the adaptation law possesses enhanced robustness with respect to noisy velocity measurements. Secondly, the controllex does not require the inclusion of high gain loops that may excite the unmodeled dynamics and amplify… (More)
Comparative experiments with various parameter estimation methods in adaptive model-based robot control are presented. These experiments were performed on a two-DOF robot manipulator linked to a transputer-based processing environment. Abstmrt-In the literature on adaptive robot control a large variety of parameter estimation methods have been proposed,… (More)
We reinterprete and improve recent results on robust control of robots by the computed method. The methods and ideas used are inspired by 'passivity based' control methods for robot manipulators and lead to a significant increase in freedom of controller implementation, thereby providing more flexibility to the designer of robot control systems.