Two prototypes of ultrasonic-based distance meter

The paper describes the hardware architecture and software strategies of two prototypes of ultrasonic-based distance meter. Prototypes are based on a digital signal controller (DSC), mandated to supervise its whole functioning. Besides driving the piezoelectric transducer, the DSC manages the digitization of received ultrasonic signal, processes acquired samples according to two different measurement algorithms, and delivers the desired result to the final user. The measurement algorithms, already been presented and validated in L. Angrisani et al. (2003, 2004, 2006) and A. Baccigalupi et al. (2003), are based respectively on quadrature demodulation and discrete extended Kalman filter (DEKF). In particular, for applications requiring fast measurement time to the detriment of accuracy, quadrature demodulation algorithm is adopted. If better measurement accuracy has to be granted, the use of DEKF-based algorithm is suggested. A number of distance measurements in free-space propagation are conducted. Obtained results are presented, and a proper performance comparison of two prototypes is drawn