Sensor fusion for improved control of piezoelectric tube scanners

In this work the measurement quality of capacitive displacement sensors is augmented with the high dynamic sensitivity of piezoelectric transducers. By combining the low-frequency performance and stability of capacitive sensors with the high sensitivity and bandwidth of piezoelectric transducers, a displacement RMS noise of 1 nm and range of 100 mum is achieved with a bandwidth of 20 kHz. The composite displacement signal is employed with a receding horizon control strategy to achieve high-speed low-noise control of a piezoelectric tube scanner.