Distance measuring device and distance measuring method

A distance measuring device that calculates a distance between a first device and a second device, at least one of which is movable, on a basis of phases of first to fourth known signals transmitted at a plurality of carrier frequencies, wherein

• the first device includes:
• a first reference signal source;
• and
• a first transceiver configured to transmit the first known signal corresponding to a first carrier frequency and the second known signal corresponding to a second carrier frequency different from the first carrier frequency, and receive the third known signal corresponding to the first carrier frequency and the fourth known signal corresponding to the second carrier frequency, using an output of the first reference signal source,
• the second device includes:
• a second reference signal source configured to operate independently from the first reference signal source;
• and
• a second transceiver configured to transmit the third known signal corresponding to the first carrier frequency and the fourth known signal corresponding to the second carrier frequency and receive the first known signal and the second known signal, using an output of the second reference signal source,
• the first or second device includes a first phase detector configured to detect phases of the third and fourth known signals received by the first transceiver,
• the first or second device includes a second phase detector configured to detect phases of the first and second known signals received by the second transceiver,
• the first or second device includes a calculating section configured to calculate a distance between the first device and the second device on a basis of a phase difference between the third and fourth known signals detected by the first phase detector and a phase difference between the first and second known signals detected by the second phase detector, and
• the first transceiver and the second transceiver transmit/receive the first known signal and the third known signal corresponding to the first known signal one time each and transmit/receive the second known signal and the fourth known signal corresponding to the second known signal one time each, performing transmission/reception a total of four times,
• wherein the first transceiver transmits a fifth known signal corresponding to a third carrier frequency different from the first carrier frequency and the second carrier frequency and receives a sixth known signal corresponding to the third carrier frequency, using an output of the first reference signal source,
• the second transceiver transmits the sixth known signal and receives the fifth known signal using an output of the second reference signal source,
• the first transceiver and the second transceiver transmit/receive the fifth and sixth known signals one time each after transmitting/receiving the first and third known signals one time each and transmitting/receiving the second and fourth known signals one time each, and
• the second transceiver receives the fifth known signal twice at a predetermined interval in transmission/reception of the fifth and sixth known signals one time each.

A distance measuring method for calculating a distance between a first device and a second device, at least one of which is movable, on a basis of phases of first to fourth known signals transmitted at a plurality of carrier frequencies, the distance measuring method comprising:

• in a first transceiver provided in the first device, transmitting the first known signal corresponding to a first carrier frequency using an output of a first reference signal source;
• in a second transceiver provided in the second device, receiving the first known signal twice at a predetermined interval and transmitting a third known signal corresponding to the first carrier frequency after receiving the first known signal, using an output of a second reference signal source operating independently from the first reference signal source;
• in the first transceiver, receiving the third known signal using an output of the first reference signal source and transmitting the second known signal corresponding to a second carrier frequency different from the first carrier frequency after receiving the third known signal, using an output of the first reference signal source;
• in the second transceiver, receiving the second known signal twice at a predetermined interval and transmitting a fourth known signal corresponding to the second carrier frequency after receiving the second known signal, using an output of the second reference signal source;
• in the first transceiver, receiving the third known signal using an output of the first reference signal source;
• in a second phase detector provided in the second device, detecting phases of the first and second known signals received by the second transceiver;
• in a first phase detector provided in the first device, detecting phases of the third and fourth known signals received by the first transceiver;
• and
• in a calculating section provided in the first device or second device, calculating a distance between the first device and the second device on a basis of phases of the first to fourth known signals detected by the first and second phase detectors
• in the first phase detector and in the second phase detector,
• detecting a first phase and a second phase for the first known signal, detecting a third phase for the third known signal, detecting a fourth phase and a fifth phase for the second known signal, and detecting a sixth phase for the fourth known signal,
• detecting a first phase for the first known signal, detecting a second phase and a third phase for the third known signal, detecting a fourth phase for the second known signal, and detecting a fifth phase and a six phase for the fourth known signal,
• detecting a first phase and a second phase for the first known signal, detecting a third phase for the third known signal, detecting a fourth phase for the second known signal, and detecting a fifth phase and a six phase for the fourth known signal, or
• detecting a first phase for the first known signal, detecting a second phase and a third phase for the third signal, detecting a fourth phase and a fifth phase for the second known signal, and detecting a sixth phase for the fourth signal, and
• in a calculating section provided in the first device or second device, calculating a distance between the first device and the second device on a basis of the first to sixth phases of the first to fourth known signals detected by the first and second phase detectors.

A distance measuring device that calculates a distance between a first device and a second device, at least one of which is movable, on a basis of phases of first to fourth known signals transmitted at a plurality of carrier frequencies, wherein

• the first device includes:
• a first reference signal source;
• and
• a first transceiver configured to transmit the first known signal corresponding to a first carrier frequency and the second known signal corresponding to a second carrier frequency different from the first carrier frequency, and receive the third known signal corresponding to the first carrier frequency and the fourth known signal corresponding to the second carrier frequency, using an output of the first reference signal source,
• the second device includes:
• a second reference signal source configured to operate independently from the first reference signal source;
• and
• a second transceiver configured to transmit the third known signal corresponding to the first carrier frequency and the fourth known signal corresponding to the second carrier frequency and receive the first known signal and the second known signal, using an output of the second reference signal source,
• the first or second device includes a first phase detector configured to detect phases of the third and fourth known signals received by the first transceiver,
• the first or second device includes a second phase detector configured to detect phases of the first and second known signals received by the second transceiver,
• the first or second device includes a calculating section configured to calculate a distance between the first device and the second device, and
• the first transceiver and the second transceiver transmit/receive the first known signal and the third known signal corresponding to the first known signal one time each and transmit/receive the second known signal and the fourth known signal corresponding to the second known signal one time each, performing transmission/reception a total of four times,
• at least one of the first phase detector and the second phase detector detects a phase twice at a predetermined interval for at least one of the first to fourth known signals, and
• the calculating section calculates the distance between the first device and the second device by cancelling a frequency difference between the first known signal and the third known signal and a frequency difference between the second known signal and the fourth known signal, by a calculation including a difference calculation of the phases obtained by the detection performed twice.