Evaluation of an active force control for flexible structure

Abstract

The conventional method of suppressing the vibration by using passive damping which consists of mounting passive material on a structure will lead to increase the weight of the structure and hence decreasing the performance. This research presented an investigation into the performance of Active Vibration Control using Active Force Control (AFC) techniques for vibration suppression of a two-dimensional flexible plate structure. The input and output data of the flexible plate were acquired through the experimental work using National Instrumentation data acquisition system and a flexible plate test rig. A sinusoidal force was applied using electromagnetic shaker as the main sources of vibration to excite the flexible plate and the dynamic response of the plate is investigated with four different boundary conditions; all edges clamped (CCCC), three edges clamped one edge free (CCCF), two edges clamped two edges free (CCFF) and one edge clamped three edges free (CFFF). The electromagnetic shaker is used in this research to produce a continuous vibration on the plate. The natural frequency of the plate is obtained analytically using the KirchofPs plate theory and then it is compared to the experimental result for all boundary conditions of the rectangular plate. An AFC refers to the use of force sensing elements to sense and provide for correction of force errors. In this research the ability of AFC algorithm will be assessed for vibration suppression of the plate with CFFF boundary condition. An accelerometer is used to sense the vibration of the flexible rectangular plate and the signal is submitted to the AFC controller algorithm. The AFC algorithm will estimate the correction force that can be supply to the plate by using piezoelectric actuator to eliminate the force due to the disturbance. The result obtained in this research confirmed the ability of thus developed AFC algorithm to control the vibration of the flexible plate efficiently.