Techniques for vibration control of a flexible robot manipulator

Z. Mohamed a1c1, A. K. Chee a1, A. W. I. Mohd Hashim a1, M. O. Tokhi a2, S. H. M. Amin a1 and R. Mamat a1
a1 Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM, Johor (Malaysia).
a2 Department of Automatic Control and Systems Engineering, The University of Sheffield (UK).

Article author query
mohamed z   [Google Scholar] 
chee ak   [Google Scholar] 
hashim aw   [Google Scholar] 
tokhi mo   [Google Scholar] 
amin sh   [Google Scholar] 
mamat r   [Google Scholar] 


This paper presents investigations into the applications and performance of positive and negative input shapers in command shaping techniques for the vibration control of a flexible robot manipulator. A constrained planar single-link flexible manipulator is considered and the dynamic model of the system is derived using the finite element method. An unshaped bang-bang torque input is used to determine the characteristic parameters of the system for design and evaluation of the input shaping control techniques. The positive and specified amplitude negative input shapers are designed based on the properties of the system. Simulation results of the response of the manipulator to the shaped inputs are presented in the time and frequency domains. Performances of the shapers are examined in terms of level of vibration reduction, time response specifications and robustness to parameters uncertainty. The effects of derivative order of the input shaper on the performance of the system are investigated. Finally, a comparative assessment of the impact amplitude polarities of the input shapers on the system performance is presented and discussed.

(Received October 25 2005)
(Published Online January 23 2006)

Key Words: Flexible manipulator; Input shaping; Simulation; Vibration control.

c1 Corresponding author. Dr. Z. Mohamed. E-mail: