Data acquisition and compression in adaptive mechanical systems

An adaptive mechanical system or smart structure system is an integration of the mechanical structures with the measurement and control systems. The goal of the control system is the stabilization, adaptation of the shape of the mechanical structure and/or the active damping of vibrations. For the shape description and control a large amount of measured and reference data is needed. This depends on the requested form and the material of the mechanical system. A concentrated controller for all data requires many connections to sensors and actuators and is difficult to design. The data compression technology, which has been widely used in telecommunication and image processing, offers the capability to reduce the redundancy or to extract the important information from the original data. There are many methods to perform data compression or information extraction, for example Karhunen-Loeve-Transformation (KLT) and methods based on Modal Filter (MF). In this paper, the techniques of MF-based method and KLT are introduced The use of these techniques in adaptive mechanical systems is then analyzed. A distributed implementation of these techniques is also discussed. Finally, the simulation results for generation of reference data using KLT and for extraction of modal coordinates using MF-based methods are presented.