Signal Processing for Single Transducer Distance Measurement Applications to Reduce the Blind Zone

摘要

Piezoelectric air ultrasound transducers typically have a small bandwidth. So they cannot be used torntransmit short signals. This leads to a blind zone which prevents measuring short distances in singlerntransducer applications, because normally receiving is not possible until transmitting is finished. Thernblind zone is significantly increased if coded signals are used which is necessary to identify differentrnsensors in a multi sensor environment to reduce crosstalk. One solution is to implement arnsimultaneous transmitting and receiving operation by model based suppression of the transmittedrnsignal. It is possible to measure distances down to 50 mm using fixed signal processing. To measurernsmaller distances the signal processing has to be modified. This contribution shows an extendedrnsignal processing for further reduction of the blind zone.