Dynamic Modeling of a Flexible Cantilever Beam: An Experimental Technique

Abstract

This paper describes an investigation of real time dynamic modeling method for a flexible cantilever beam, as an approximation of a robot flexible link, using experimental measurement techniques. The beam is equipped with a number of strain gauges to measure the corresponding nodal flexibilities and using them to obtain its real-time dynamic model. Two methods are proposed; the 1st method is based on approximating the beam deflection by a 4th order polynomial curve while the 2nd one is based on the solution of its Eulerbernoulli equation. The polynomial constants are obtained by real-time estimation using the readings of the strain gauges. These readings are used to estimate the beam temporal solution in the 2nd method. The error in the beam tip deflection is reduced to 0.01% by relocating the last strain gauge at 12.5% instead of 30% from its tip. Both methods show good agreement with the general beam theory and results.