15th Triennial World Congress of the International Federation of Automatic Control
  Barcelona, 21–26 July 2002 
INPUT SHAPING FOR A PD POSITION CONTROLLER UNDER COULOMB FRICTION
Dr. Keith Hekman, Jason Lawrence and Dr. William Singhose
The American University in Cairo
Department of Mechanical Engineering
113 Kasr El Aini St. PO Box 2511 Cairo, 11511 Egypt
hekman@aucegypt.edu
Georgia Institute of Technology
George W. Woodruff School of Mechanical Engineering
Atlanta, GA 30332-0405

A proportional plus derivative controller is used on a system with coulomb friction. The proportional control decreases steady state error, while the derivative control reduces system oscillations. However, the derivative control also makes the system response more sluggish. As an alternative, input shaping can be used to reduce the system oscillations. Traditional input shapers are not designed to include the effects of coulomb friction so they may not work well in all cases. A new method of developing an input shaper to include the effects of coulomb friction is discussed. Simulation and experimentation show the effectiveness of the new shaper.
Keywords: Position Control, Shaping Filters, Proportional Plus Derivative Controllers Coulomb Friction, Nonlinear Models
Session slot T-Th-A14: Control Design for Mechanical Systems/Area code 2a : Control Design