4.1 Introduction

The ideal smart structure is one which is capable of sensing its environment and is also aware of its current state of condition and motion. It is capable of diagnosing damage to itself and taking action to minimise the consequences. It is capable of adapting its static and dynamic behaviour through feedback control. A prerequisite for such a structure is that it should have integrated sensing and actuation capabilities. That is the capability for sensing and movement should be built-in, but perhaps more importantly designed-in.

Many types of sensor are available, some localised, some distributed. Each has its own advantages and disadvantages. The generic smart structure will need to process information from sensors of both types. Remote sensing is necessary for identifying possible hazards and harsh environments and providing information to the control algorithms which will direct the structure to avoid problems. Distributed sensing may well be needed for the location and assessment of structural damage.

The efficient use of integrated sensors of different types requires the availability of appropriate signal processing technology. Sophisticated pattern recognition algorithms are needed. In the case of remote sensors, data representing possible hazards must be classified so that appropriate action can be taken. In many military applications, target recognition is critical. This is the concern of image processing, the subject of much current research. In the case of...