Optimization and Systems Theory Seminar
Friday, February 18, 2000, 11.00-12.00, Room 3721, Lindstedtsvägen 25

Mattias Nordin
Division of Optimization and Systems Theory
Department of Mathematics
E-mail: mattias.nordin@math.kth.se

Nonlinear backlash compensation of speed controlled elastic system

Backlash is one of the most important non-linearities that limit the performance of speed and position control in industrial, robotics, automotive, automation and other applications. This thesis deals with various aspects of two-mass systems with backlash, representing the majority of such system, such as modeling, identification and control.

One important contribution of this thesis is the novel backlash compensation method. The method is based on smart and soft switching between well designed linear controllers. The algorithm, and design method, is successfully tested by simulations and experiments on a real system.

Another important contribution is the new models for backlash in drive trains, also showing the limitations of the dead zone models. The new models were also successfully compared to measurements on a laboratory system.

An extensive survey of previous methods for control of systems with backlash is also included, as well as a winning QFT design for a benchmark problem of an elastic system without backlash.

Calendar of seminars
Last update: February 7, 2000 by Anders Forsgren, anders.forsgren@math.kth.se.