Patent ID: 11899097
Assignee: TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 5:
6. The distance measurement device according to claim 1, wherein
the first transmitter-receiver samples the second phase information for one period of the second demodulated signal or longer,
the second transmitter-receiver performs, twice or more, sampling of the first phase information for one period of the first demodulated signal or longer, and
the calculation unit
obtains, for each of the second demodulated signal and the first demodulated signal, two samples, phase change of which is maximized through subtraction of a temporally previous sample of a sample,
calculates, by using three continuous samples including the two samples of the first demodulated signal for a first time, an elapsed time tb1 of the second device from a time point at which the reception of the first demodulated signal is started, to a time point at which the first demodulated signal is sampled is obtained,
calculates, by using three continuous samples including the two samples of the second demodulated signal, an elapsed time ta1 of the first device from a time point at which the reception of the second demodulated signal is started, to a time point at which the second demodulated signal is sampled is obtained,
calculates, by using three continuous samples including the two samples of the first demodulated signal for a second time, an elapsed time tb2 of the second device from a time point at which the reception of the first demodulated signal is started, to a time point at which the first demodulated signal is sampled is obtained,
calculates a first flight time tx,err1 including error by

tx,err1=(TS−ta1−tb1)/2

where TS represents the first or second sampling period,
calculates a second flight time tx,err2 including error by

tx,err2=(TS−ta1−tb2)/2

calculates an average flight time by averaging the first flight time tx,err1 and the second flight time tx,err2 and
calculates the distance based on the average flight time.