Time of flight measurement method and apparatus

Patent metadata

Field	Value
Publication number	US-12535564-B2
Application number	US-202217964691-A
Country	US
Kind code	B2
Filing date	Oct 12, 2022
Priority date	Apr 14, 2020
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A time of flight (TOF) measurement method and apparatus are provided, including a controller, a time to digital converter, a pulse transmitter, and a pulse receiver. The controller is configured to control, in a working period according to a predetermined transmit rule, the pulse transmitter to sequentially send M transmit pulses. The pulse receiver is configured to receive N feedback pulses in the working period. The time to digital converter is configured to obtain time of flight information corresponding to the N feedback pulses. The controller is further configured to obtain a target time of flight based on the time of flight information corresponding to the N feedback pulses, and obtain a target distance based on the target time of flight.

First claim

What is claimed is:

1 . A distance measurement apparatus, comprising:
a time to digital converter; a pulse transmitter; a pulse receiver connected to the time to digital converter; and a controller separately connected to the time to digital converter, the pulse transmitter, and the pulse receiver; wherein the controller sequentially sends M transmit pulses in M transmit periods of a working period based on M transmit times, wherein one transmit pulse is in one transmit period and a transmit time of an i th of the M transmit pulses is obtained based on a start moment of a transmit period of the i th of the M transmit pulses and an i th of M latencies, wherein M is an integer greater than 1; the pulse receiver is configured to receive N feedback pulses in the working period, wherein N is an integer greater than 1; the time to digital converter is configured to obtain time of flight information corresponding to the N feedback pulses; and the controller is further configured to obtain a target time of flight that appears for a largest quantity of times in the time of flight information corresponding to the N feedback pulses, and obtain a target distance based on the target time of flight.

2 . The distance measurement apparatus according to claim 1 , wherein when the i th of the M transmit pulses is transmitted, time of flight information of the i th transmit pulse is a difference between a timing end moment of the time to digital converter and a timing start moment of the time to digital converter, wherein
the timing end moment of the time to digital converter is a moment at which the pulse receiver receives a feedback pulse in the transmit period of the i th transmit pulse; and the timing start moment of the time to digital converter corresponds to the transmit time of the i th transmit pulse; or the timing start moment of the time to digital converter corresponds to the start moment of the transmit period of the i th transmit pulse.

3 . The distance measurement apparatus according to claim 2 , wherein
when the timing start moment of the time to digital converter corresponds to the transmit time of the i th transmit pulse, time of flight of the N feedback pulses is the time of flight information corresponding to the N feedback pulses; or the distance measurement apparatus further comprises a latency compensator connected to the controller, and the latency compensator is configured to perform latency compensation on the time of flight information of the N feedback pulses based on the M latencies, to obtain the time of flight of the N feedback pulses when the timing start moment of the time to digital converter corresponds to the start moment of the transmit period of the i th transmit pulse.

4 . The distance measurement apparatus according to claim 3 , further comprising a memory connected to the controller, wherein the memory is configured to store the time of flight of the N feedback pulses.

5 . The distance measurement apparatus according to claim 1 , further comprising a latency generator connected to the controller, wherein the M latencies are obtained by the controller from the latency generator.

6 . The distance measurement apparatus according to claim 1 , wherein the M latencies are generated by the controller.

7 . The distance measurement apparatus according to claim 1 , wherein the M latencies are obtained through setting based on a true random number or a pseudo random number, or according to a preset rule.

8 . A method of distance measurement, comprising:
sequentially sending, by an electronic device, M transmit pulses in M transmit periods of a working period based on M transmit times, wherein one transmit pulse is in one transmit period and a transmit time of an i th of the M transmit pulses is obtained based on a start moment of a transmit period of the i th of the M transmit pulses and an i th of M latencies and M is an integer greater than 1; receiving, by the electronic device, N feedback pulses in the working period, wherein N is an integer greater than 1; obtaining, by the electronic device, time of flight information corresponding to the N feedback pulses; and obtaining, by the electronic device, a target time of flight that appears for a largest quantity of times in the time of flight information corresponding to the N feedback pulses, and obtaining a target distance based on the target time of flight.

9 . The method according to claim 8 , wherein when the i th of the M transmit pulses is transmitted, time of flight information of the i th transmit pulse is a difference between a timing end moment of a timer and a timing start moment of the timer, wherein
the timing end moment of the timer is a moment at which the electronic device receives a feedback pulse in the transmit period of the i th transmit pulse; and the timing start moment of the timer corresponds to the transmit time of the i th transmit pulse; or the timing start moment of the timer corresponds to the start moment of the transmit period of the i th transmit pulse.

10 . The method according to claim 9 , wherein when the timing start moment of the timer corresponds to the transmit time of the i th transmit pulse, time of flight of the N feedback pulses is the time of flight information corresponding to the N feedback pulses; or
when the timing start moment of the timer corresponds to the start moment of the transmit period of the i th transmit pulse, the time of flight of the N feedback pulses is obtained through latency compensation.

11 . The method according to claim 8 , wherein the M latencies are obtained through setting based on a true random number or a pseudo random number, or according to a preset rule.

12 . An electronic device, comprising:
a processor; and a distance measurement apparatus connected to the processor, the distance measurement apparatus comprising: a time to digital converter; a pulse transmitter; a pulse receiver connected to the time to digital converter; and a controller separately connected to the time to digital converter, the pulse transmitter, and the pulse receiver; wherein the controller is configured to control the pulse transmitter to sequentially send M transmit pulses in M transmit periods of a working period based on M transmit times, wherein one transmit pulse is in one transmit period and a transmit time of an i th of the M transmit pulses is obtained based on a start moment of a transmit period of the i th of the M transmit pulses and an i th of M latencies, wherein M is an integer greater than 1; the pulse receiver is configured to receive N feedback pulses in the working period, wherein N is an integer greater than 1; the time to digital converter is configured to obtain time of flight information corresponding to the N feedback pulses; and the controller is further configured to obtain a target time of flight that appears for a largest quantity of times in the time of flight information corresponding to the N feedback pulses, and obtain a target distance based on the target time of flight; wherein the distance measurement apparatus is configured to send the target distance to the processor, and the processor is configured to perform processing on the target distance.

13 . The electronic device according to claim 12 , wherein when the i th of the M transmit pulses is transmitted, time of flight information of the i th transmit pulse is a difference between a timing end moment of the time to digital converter and a timing start moment of the time to digital converter, wherein
the timing end moment of the time to digital converter is a moment at wh

Assignees

• Huawei Tech Co Ltd

Inventors

• Yu Kai
• Qu Fengguang
• Yu Feng
• He Shichuan
• Jiang Kewei

Classifications

• G01S17/14 Primary

  wherein a voltage or current pulse is initiated and terminated in accordance with the pulse transmission and echo reception respectively, e.g. using counters · CPC title

• G01S7/4876

  by removing unwanted signals (G01S7/495 takes precedence) · CPC title

• G01S7/4865 Primary

  Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak (peak detection in noise, signal conditioning G01S7/487) · CPC title

• G01S7/487

  Extracting wanted echo signals {, e.g. pulse detection} · CPC title