Time-of-flight distance measurement method, system and equipment

Abstract

The invention discloses a time-of-flight distance measurement method, system and equipment. The method comprises the following steps: calculating the number of noise photons according to an initial histogram, wherein the initial histogram comprises continuous time intervals, and the time intervals comprise counting values of photons in the pulse light beams collected by the collector; determining a pulse extraction condition according to the number of noise photons, and searching the initial histogram according to the pulse extraction condition to extract a search interval meeting the pulse extraction condition and a corresponding histogram index, wherein the search interval comprises a plurality of time intervals, the number of the time intervals in the search interval is determined according to the pulse width of a pulse light beam emitted by an emitter, and the histogram index corresponds to a first time interval in the search interval; calculating a second flight time by taking the extracted search interval as a second histogram, and calculating the flight time of the pulse beam from emission to receiving according to the second flight time and the first flight time corresponding to the histogram index in the initial histogram; and calculating the distance of the object by using the flight time.

Description

technical field [0001] The invention relates to the technical field of ranging, in particular to a ranging method, system and equipment based on photon counting multi-echo time-of-flight. Background technique [0002] Using the principle of time of flight (ToF, Time of Flight) can measure the distance of the target to obtain a depth image containing the depth value of the target, and the distance measurement system based on the principle of time of flight has been widely used in consumer electronics, unmanned vehicles, AR / VR and other fields. The distance measurement system based on the time-of-flight principle usually includes a transmitter and a collector. The transmitter emits a pulsed beam to irradiate the target field of view and the collector collects the reflected beam, and calculates the flight time of the beam from emission to reflection reception to calculate the distance of the object. . Among them, the time-to-digital converter (TDC) is used to record the fligh...

AI Technical Summary

Problems solved by technology

[0003] At present, the peak-finding method based on the histogram generally uses a single echo to determine the flight time and calculate the distance, that is, only one pulse peak position appears in the histogram, but the single-echo algorithm is vulnerable to multi-path scattering, multi-machine interference, and emission spots Influencing factors such as truncation lead to the generation of multiple effective echo signals; or when the distance measuring system is in a special use scenario, such as rainy and foggy weather, the surface of the system is covered by rain, glass and other objects, some interference echo signals will also be generated, and finally in the There are multiple peak positions in the histogram, and the system cannot determine whether each peak position is a valid signal or an interference signal, resulting in the inability to complete the distance measurement

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