Vibration-free position control for a two degrees of freedom flexible-beam sensor

Castillo-Berrio C. F. , Feliu-Badle V.

MECHATRONICS, vol.27, pp.1-12, 2015 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 27
  • Publication Date: 2015
  • Doi Number: 10.1016/j.mechatronics.2015.01.005
  • Title of Journal : MECHATRONICS
  • Page Numbers: pp.1-12
  • Keywords: Motion control, Vibration suppression, Flexible-beam, Force/torque sensor, State linearisation


This work presents a position control for a two degree of freedom flexible-beam made of a composite material, whose aim is to control the tip of the flexible-beam by decreasing the vibration when the beam moves. A mechatronic unit that uses a multi-axis force/torque sensor has been specially designed and we propose to control the system by using a reduced dynamic model. The control method makes use of an inner-loop to control the position of two servo-motors, by means of PID regulators, and an outer-loop that cancels the tip vibration. Moreover, the closed-loop motor dynamics has been reduced by using a series connection of filters that invert its dynamics. The motor controllers have proved to be fast and precise, and cancel the non-modelled components of the motor friction without the need for a previous estimation. The flexible-beam vibration has been controlled by implementing an input-state feedback linearisation which includes compensation terms for the nonlinear beam dynamics, a linear feedback control law and a full state estimator. The experimental validation of the complete control method showed a significant trajectory tracking of the tip, while vibrations were prevented. (C) 2015 Elsevier Ltd. All rights reserved.