Robust shape control of flexible structures using strain-measurement-gauges and piezoelectric stack actuators

Deflection measurement is an absolute necessity if the shape of a flexible, mechanical structure has to be controlled. Commonly optical or inductance-based sensors are used to determine deflections. Under laboratory conditions both sensor types yield good results, though for practical applications several restrictions have to be taken into account. Both sensor types measure relative deflections, which leads to the necessity to fix the sensors in space. Furthermore both methods can only be used for small deflections.