Robust control for servo-mechanisms under inexact friction compensation

Abstract Uncertainties in the parameters but also in the structure of the friction model may lead to inexact friction compensation in servo-mechanisms. This will lead to differences between the predicted friction and the real friction forces, provoking, in certain cases (overcompensation) an oscillatory behaviour. This paper proposes a new control scheme seeking to strengthen the closed-loop system properties in the eventuality of friction overcompensation. This control design has the advantage that, in the case of friction overcompensation, the oscillations can be reduced in amplitude and modified in frequency independently of the closed-loop system specifications.

[1]  J. Maron.  Nonlinear Identification and Observer Based Compensation of Friction in Mechanical Systems , 1989 .

[2]  M. D. Hersey,et al.  Theory and research in lubrication : foundations for future developments , 1966 .

[3]  C. A. Canudas De Wit,et al.  Adaptive Control for Partially Known Systems: Theory and Applications , 1989 .

[4]  Brian S. R. Armstrong,et al.  Dynamics for robot control: friction modeling and ensuring excitation during parameter identification , 1988 .

[5]  R. Oldenburger,et al.  Effects of Extra Sinusoidal Inputs to Nonlinear Systems , 1962 .

[6]  Carlos Canudas de Wit,et al.  Adaptive Friction Compensation in Robot Manipulators: Low Velocities , 1991, Int. J. Robotics Res..

[7]  Béla Lantos.  Identification and adaptive control of robots , 1993 .

[8]  Carlos Canudas de Wit,et al.  Adaptive friction compensation in DC motor drives , 1986, Proceedings. 1986 IEEE International Conference on Robotics and Automation.

[9]  Brian Armstrong,et al.  Friction: experimental determination, modeling and compensation , 1988, Proceedings. 1988 IEEE International Conference on Robotics and Automation.

[10]  I︠a︡. Z. T︠S︡ypkin.  Relay Control Systems , 1985 .

[11]  J. C. Maron,et al.  Identification and Adaptive Control of Mechanical Systems with Friction , 1990 .

[12]  Richard Paul,et al.  Manipulator compliance based on joint torque control , 1980, 1980 19th IEEE Conference on Decision and Control including the Symposium on Adaptive Processes.

[13]  J. C. Maron,et al.  NONLINEAR IDENTIFICATION AND OBSERVER BASED COMPENSATION OF FRICTION IN MECHANICAL SYSTEMS , 1989 .

[14]  Craig D. Walrath,et al.  Adaptive bearing friction compensation based on recent knowledge of dynamic friction , 1984, Autom..

[15]  G. Brandenburg,et al.  Position Control for Elastic Pointing and Tracking Systems with Gear Play and Coulomb Friction and Application to Robots , 1991 .

[16]  A. Tustin,et al.  The effects of backlash and of speed-dependent friction on the stability of closed-cycle control systems , 1947 .