Optical measurement of cable and string vibration

Article type: Research Article

Authors: Achkire, Y. | Preumont, A.

Affiliations: CALTECH, Applied Mechanics, Mail code 104–44, Pasadena, CA 91125, USA | Université Libre de Bruxelles, Active Structures Laboratory, Department of Mechanical Engineering and Robotics, CP 165, 50 Av. F.D. Roosevelt, 1050 Brussels, Belgium

Abstract: This paper describes a non contacting measurement technique for the transverse vibration of small cables and strings using an analog position sensing detector. On the one hand, the sensor is used to monitor the cable vibrations of a small scale mock‐up of a cable structure in order to validate the nonlinear cable dynamics model. On the other hand, the optical sensor is used to evaluate the performance of an active tendon control algorithm with guaranteed stability properties. It is demonstrated experimentally, that a force feedback control law based on a collocated force sensor measuring the tension in the cable is feasible and provides active damping in the cable.

Keywords: Photodetector, laser, cable vibration, active control, cable‐stayed bridges

Journal: Shock and Vibration, vol. 5, no. 3, pp. 171-179, 1998