CN117872387A - Ranging method, ranging device, ranging apparatus, and storage medium - Google Patents

Abstract

The embodiment of the application is suitable for the technical field of ranging, and provides a ranging method, a ranging device, ranging equipment and a storage medium, wherein the ranging method comprises the following steps: sequentially transmitting 2n modulated coded pulse signals in the target pulse signals to an object to be detected, and sequentially receiving each returned coded pulse signal to respectively generate an original histogram with an avalanche count peak value; according to the generation sequence of each avalanche count peak value and the generation interval duration between every two adjacent avalanche count peak values, respectively superposing the avalanche count peak values corresponding to every n coding pulse signals in sequence to obtain a first superposition histogram and a second superposition histogram; performing interference elimination processing on the first superimposed histogram and the second superimposed histogram to generate a target interference-free histogram corresponding to the target pulse signal; and determining the interval distance between the target non-interference histogram and the object to be measured. By adopting the method, the distance measuring time and power consumption required when the distance of a far object to be measured is measured can be reduced.

Description

Ranging method, ranging device, ranging apparatus, and storage medium

Technical Field

The application belongs to the technical field of ranging, and particularly relates to a ranging method, a ranging device, ranging equipment and a storage medium.

Background

Time Of Flight (TOF) methods can generate histograms by emitting a pulsed signal beam to an object to be measured and capturing the returned photon pulse signal based on a single photon detector (e.g., a single photon avalanche photodiode). And then, calculating the distance between the object to be measured according to the wave crest in the statistical histogram.

Currently, in order to measure the distance of a distant object to be measured, it is generally required to emit a pulse signal beam of high peak optical power to the object to be measured a plurality of times in succession. The statistical multiple histograms are then superimposed to increase photon signal intensity. For example, a pulsed signal beam of 4 times high peak optical power is continuously emitted from an object to be measured.

However, in order to avoid interference between received photon pulse signals, a longer interval length is required for the transmission interval length between adjacent two transmission pulse signal beams. Further, when the distance of the object to be measured is measured farther, not only a lot of distance measurement time is required, but also a lot of power consumption is required.

Disclosure of Invention

The embodiment of the application provides a ranging method, a ranging device, ranging equipment and a storage medium, which can solve the problems that more ranging time is required to be consumed and more power consumption is required when the distance of a far object to be measured is measured.

In a first aspect, an embodiment of the present application provides a ranging method, including:

sequentially transmitting 2n modulated coded pulse signals in the target pulse signals to an object to be detected, and sequentially receiving each returned coded pulse signal to respectively generate an original histogram with an avalanche count peak value; the transmission interval duration between each encoded pulse signal is different; n is an integer of 2 or more;

according to the generation sequence of each avalanche count peak value and the generation interval duration between every two adjacent avalanche count peak values, respectively superposing the avalanche count peak values corresponding to every n coding pulse signals in sequence to obtain a first superposition histogram and a second superposition histogram; the first superposition histogram is obtained by superposing avalanche count peaks from 1 st to n th in the generation sequence; the second superposition histogram is obtained by superposing avalanche count peaks from n+1th to 2n in the generation sequence;

performing interference elimination processing on the first superimposed histogram and the second superimposed histogram to generate a target interference-free histogram corresponding to the target pulse signal;

and determining the interval distance between the target non-interference histogram and the object to be measured.

In a second aspect, embodiments of the present application provide a ranging apparatus, the apparatus comprising:

The execution module is used for sequentially transmitting 2n coded pulse signals modulated in the target pulse signals to an object to be detected, and sequentially receiving each returned coded pulse signal to respectively generate an original histogram with an avalanche count peak value; the transmission interval duration between each encoded pulse signal is different; n is an integer of 2 or more;

the superposition module is used for sequentially and respectively superposing the avalanche count peaks corresponding to every n coding pulse signals according to the generation sequence of each avalanche count peak and the generation interval duration between every two adjacent avalanche count peaks to obtain a first superposition histogram and a second superposition histogram; the first superposition histogram is obtained by superposing avalanche count peaks from 1 st to n th in the generation sequence; the second superposition histogram is obtained by superposing avalanche count peaks from n+1th to 2n in the generation sequence;

the generating module is used for carrying out interference elimination processing on the first superimposed histogram and the second superimposed histogram and generating a target interference-free histogram corresponding to the target pulse signal;

and the distance measuring module is used for determining the interval distance between the target non-interference histogram and the object to be measured.

In a third aspect, embodiments of the present application provide a ranging apparatus comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing a method according to the first aspect as described above when executing the computer program.

In a fourth aspect, embodiments of the present application provide a computer readable storage medium storing a computer program which, when executed by a processor, implements a method as in the first aspect described above.

In a fifth aspect, embodiments of the present application provide a computer program product for causing a ranging apparatus to perform the method of the first aspect described above when the computer program product is run on the ranging apparatus.

Compared with the prior art, the embodiment of the application has the beneficial effects that: the ranging apparatus may sequentially transmit the coded pulse signals to the object to be measured according to a transmission interval duration between 2n coded pulse signals in the target pulse signal, and receive an original histogram having an avalanche count peak value generated by each of the returned coded pulse signals. Where n is required to be 2 or more. And then, according to the generation sequence of each avalanche count peak value and the generation interval duration between two adjacent avalanche count peak values, respectively superposing the avalanche count peak values corresponding to the 1 st to n coding pulse signals and superposing the avalanche count peak values corresponding to the n+1st to 2n coding pulse signals in turn to obtain a first superposition histogram and a second superposition histogram. Wherein the transmission interval duration between any two adjacent coded pulse signals in the modulated 2n coded pulse signals is different. Therefore, when the two avalanche count peaks in the original histogram are superimposed according to the corresponding emission interval duration (that is, the generation sequence of the avalanche count peaks), each avalanche count peak formed by the optical signal returned by the object to be measured can be superimposed correspondingly based on the emission interval duration. Namely, n avalanche count peaks corresponding to the object to be measured are enhanced in the first superimposed histogram and the second superimposed histogram. However, avalanche count peaks (interference peaks) formed by optical signals returned from a plurality of other non-objects in the original histogram are not spaced apart from each other by a specially set emission interval duration. Therefore, the avalanche count peak corresponding to the non-object to be measured cannot be subjected to peak superposition based on the emission interval duration. That is, in the first superimposed histogram and the second superimposed histogram, the avalanche count peak corresponding to the non-object to be measured cannot be enhanced. Therefore, the interference of the avalanche count peak of the non-object to be measured on the avalanche count peak of the object to be measured can be reduced. Based on the method, the ranging equipment can perform interference elimination based on the first superimposed histogram and the second superimposed histogram corresponding to the enhanced avalanche count peak value to obtain a target interference-free histogram, and accurately determine the interval distance between the ranging equipment and the object to be measured according to the target interference-free histogram. In the ranging process, n coded pulse signals are coded into a group of pulse signal beams for ranging, so that the peak power in the original pulse signal can be equally distributed to 2n coded pulse signals. Furthermore, the need for peak optical power and power consumption of the light source is reduced. And because the transmission interval duration between any two adjacent coded pulse signals in the modulated 2n coded pulse signals is different, the interference between avalanche count peaks can be avoided, and therefore, the transmission interval duration between the two adjacent coded pulse signals can be free from setting longer interval duration. Furthermore, when the distance of a distant object to be measured can be measured, the distance measuring time required to be consumed can be reduced. That is, a more distant ranging performance can be obtained also in the case of a limited ranging time and peak light source power.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following description will briefly introduce the drawings that are needed in the embodiments or the description of the prior art, it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a flowchart of an implementation of a ranging method according to an embodiment of the present application;

fig. 2 is a schematic diagram of a coding structure of a target pulse signal in a ranging method according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a histogram in a ranging method according to an embodiment of the present application;

FIG. 4 is a schematic diagram of an implementation of generating a first superimposed histogram and a second superimposed histogram in a ranging method according to an embodiment of the present application;

fig. 5 is a schematic diagram of an application scenario in which avalanche count peaks are superimposed in a ranging method according to an embodiment of the present application;

fig. 6 is a schematic diagram of an application scenario of a target non-interference histogram in a ranging method according to an embodiment of the present application;

Fig. 7 is a schematic view of an application scenario of a first superimposed histogram and a second superimposed histogram in a ranging method according to an embodiment of the present application;

fig. 8 is a schematic diagram of an application scenario of a target non-interference histogram in a ranging method according to another embodiment of the present application;

fig. 9 is a schematic structural diagram of a ranging device according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a ranging apparatus according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In addition, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.

The time-of-flight method may generate a histogram by emitting a pulsed signal beam toward an object to be measured and capturing a returned photon pulse signal based on a single photon detector (e.g., a single photon avalanche photodiode). And then, calculating the distance between the object to be measured according to the wave crest in the statistical histogram.

Currently, in order to measure the distance of a distant object to be measured, it is generally required to emit a pulse signal beam of high peak optical power to the object to be measured a plurality of times in succession. The statistical multiple histograms are then superimposed to increase photon signal intensity. For example, a pulsed signal beam of 4 times high peak optical power is continuously emitted from an object to be measured.

However, in order to avoid interference between received photon pulse signals, a longer interval length is required for the transmission interval length between adjacent two transmission pulse signal beams. Further, when the distance of the object to be measured is measured farther, not only a lot of distance measurement time is required, but also a lot of power consumption is required.

Based on this, in order to reduce the distance measurement time required to be consumed when measuring the distance of a distant object to be measured, the embodiment of the application provides a distance measurement method, which can be applied to a distance measurement device. For example, a time-of-flight sensor, embodiments of the present application do not impose any limitations on the specific type of ranging device.

Referring to fig. 1, fig. 1 shows a flowchart for implementing a ranging method according to an embodiment of the present application, where the ranging method includes the following steps:

s101, sequentially transmitting 2n coded pulse signals modulated in the target pulse signals to an object to be detected, and sequentially receiving each returned coded pulse signal to respectively generate an original histogram with an avalanche count peak value.

In an embodiment, the transmission interval duration may be set according to an actual scenario, which is not limited. It should be noted that, when the transmission interval duration is set, the transmission interval duration should be different between each encoded pulse signal. And n is an integer greater than or equal to 2, and for convenience of explanation, n is 2 in this embodiment, the following description will be made. Wherein the object to be measured includes, but is not limited to, a human, an animal or a static obstacle, which is not limited thereto.

When the ranging device sequentially transmits the coded pulse signals to the object to be measured, the generation sequence of the avalanche count peak values generated in the original histogram is also the same as the transmission sequence of the coded pulse signals. In this embodiment, only the case where the ranging device transmits the coded pulse signal to the object to be detected in the detection space in the preset direction is taken as an example for explanation, and the preset direction may be any detection direction in the detection space.

As an example, referring to fig. 2, fig. 2 is a schematic diagram of a coding structure of a target pulse signal in a ranging method according to an embodiment of the present application. For example, fig. 2 may include 4 coded pulses a1, a2, a3, a4, and the transmission interval duration between each two adjacent coded pulse signals may be different. For example, the transmission interval duration between a1 and a2 may be 47ns, the transmission interval duration between a2 and a3 may be 67ns, and the transmission interval duration between a3 and a4 may be 87ns.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a histogram in a ranging method according to an embodiment of the present application. In fig. 3, the abscissa of the histogram is time, and the ordinate is avalanche count. The avalanche count peaks of different colors are included in fig. 3 to correspond to different target pulse signals for ease of explanation. That is, fig. 3 includes avalanche count peaks generated by two target pulse signals. And, the highest peak red avalanche count peak is formed by superposition of two different red avalanche count peaks. Therefore, in fig. 3, the target pulse signal corresponding to blue includes 6 avalanche count peaks, and when two different red avalanche count peaks are not superimposed, the number of red avalanche count peaks is also 6, and 3 times as large as 2, which satisfies the above condition.

S102, according to the generation sequence of each avalanche count peak value and the generation interval duration between every two adjacent avalanche count peak values, the avalanche count peak values corresponding to every n coding pulse signals are respectively overlapped in sequence, and a first overlapped histogram and a second overlapped histogram are obtained.

In one embodiment, the generation sequence has been explained above, which will not be explained. It is understood that the generation interval duration is the transmission interval duration in step S101.

It should be noted that, the 2n avalanche count peaks are all located in the original histogram, so according to the generating sequence, the 1 st to n th avalanche count peaks in the generating sequence may be sequentially superimposed to obtain a first superimposed histogram, and the n+1 st to 2n th avalanche count peaks in the generating sequence may be superimposed to obtain a second superimposed histogram.

Alternatively, referring to fig. 4, the ranging apparatus may superimpose 2n avalanche count peaks according to steps S401 to S403 as shown in fig. 4. The details are as follows:

s401, shifting each avalanche count peak value in the original histogram by a target interval duration according to the target interval durations corresponding to the first avalanche count peak value and the adjacent second avalanche count peak value, and obtaining a shifted histogram with the shifted avalanche count peak value.

S402, superposing all avalanche count peaks in the same time in the original histogram and the shifted histogram to obtain an initial superposition histogram.

In an embodiment, the first avalanche count peak is an avalanche count peak that needs to be superimposed currently, and a generation sequence of the avalanche count peak is known. Thus, when determining the first avalanche count peak, the second avalanche count peak will also be a known avalanche count peak. And, the target interval duration will also be correspondingly determined. And the initial superposition histogram comprises superposition avalanche count peaks formed by superposition of the first avalanche count peak and the second avalanche count peak.

Illustratively, in the order of generation, the first avalanche count peak should be the first avalanche count peak generated at the first time of superposition, and the second avalanche count peak should be the second avalanche count peak.

As an example, taking the number of avalanche count peaks as 4, a first superimposed histogram is generated as an example. Referring to fig. 5, fig. 5 is a schematic diagram of an application scenario in which avalanche count peaks are superimposed in a ranging method according to an embodiment of the present application. Referring to the portions A1, B1, and H1 in fig. 5, A1 is an original histogram including avalanche count peaks generated from 4 encoded pulse signals, respectively, B1, B2, B3, and B4. When the avalanche count peaks of B1 and B2 are superimposed, all the avalanche count peaks in the original histogram can be shifted forward by the generation interval duration between B1 and B2, so as to obtain a shifted histogram B1 with shifted avalanche count peaks. At this time, the avalanche count peak b1 in the original histogram will be at the same time as the avalanche count peak b2 in the shifted histogram. Based on this, after the respective avalanche count peaks at the same time in the original histogram and the shifted histogram are superimposed, the initial superimposed histogram H1 obtained will contain a superimposed avalanche count peak b12 formed by the avalanche count peak b1 and the avalanche count peak b 2.

As can be seen from fig. 5, since the transmission interval lengths between two adjacent coded pulse signals are different, the generation interval lengths between any two adjacent avalanche count peaks are also different. Based on this, it can be understood that when shift-superimposing is performed according to the target interval lengths corresponding to the first avalanche count peak and the second avalanche count peak, it is common that only the first avalanche count peak and the second avalanche count peak are at the same time. Furthermore, when the original histogram receives avalanche count peaks generated by a plurality of echo signals (including interference peaks generated by coded pulse signals returned by other non-objects to be detected), the avalanche count peaks generated by the coded pulse signals returned by the objects to be detected can be better enhanced by adopting the steps, and the avalanche count peaks corresponding to the interference echo signals can be restrained.

S403, taking the initial superposition histogram as a new original histogram, and repeatedly executing the steps of obtaining a shift histogram and the initial superposition histogram by overlapping the new first avalanche count peak value of the avalanche count peak value until the avalanche count peak values corresponding to every n coding pulse signals are respectively superposed, so as to obtain a first superposition histogram and a second superposition histogram.

In one embodiment, the superimposed avalanche count peak is superimposed by the first avalanche count peak and the second avalanche count peak, and therefore, when the superimposed avalanche count peak is taken as a new first avalanche count peak, the third avalanche count peak will be an adjacent second avalanche count peak.

However, it should be specifically noted that after the shifted histogram is obtained, the shifted histogram may include two third avalanche count peaks. That is, referring to fig. 5, there will be two avalanche count peaks b3. However, the generation interval period (target interval period) between the second avalanche count peak and the third avalanche count peak is fixed.

Based on this, when the above steps S401 and S402 are repeatedly performed with the initial superimposed histogram as a new original histogram and with the superimposed avalanche count peak as a new first avalanche count peak, each avalanche count peak in the original histogram (initial superimposed histogram) is shifted based on the target interval duration, and also only one third avalanche count peak b3 will be at the same time as the first avalanche count peak. For example, when the initial superimposed histogram H1 in fig. 5 is taken as a new original histogram and b12 is taken as the first avalanche count peak, the second avalanche count peak thereof will be b3 in the initial superimposed histogram H1. Further, in the generated new initial superimposed histogram, the first avalanche count peak is superimposed by the first, second, and third corresponding avalanche count peaks, respectively.

To sum up, the ranging apparatus may repeatedly perform the steps S401 to S402 until the avalanche count peaks corresponding to the 1 st to n th encoded pulse signals are superimposed to obtain the first superimposed histogram.

And superposing avalanche count peaks corresponding to the n+1th to 2n coded pulse signals to obtain a second superposition histogram in a manner similar to that described above. Specifically, referring to the portions A2, B2, and H2 in fig. 5, A2 includes avalanche count peaks generated from 4 encoded pulse signals, respectively bn-1, bn, bn+1, and bn+2. Wherein bn-1 and bn have been processed when generating the first superimposed histogram. This time, an example of generating a second superimposed histogram is to start superimposition from the n+1th avalanche count peak (bn+1) and the n+2th avalanche count peak (bn+2).

Illustratively, when the avalanche count peaks of bn+1 and bn+2 are superimposed, all avalanche count peaks in the original histogram may be shifted forward by the generation interval duration between bn+1 and bn+2, resulting in a shifted histogram B2 with shifted avalanche count peaks. At this time, the avalanche count peak bn+1 in the original histogram will be at the same time as the avalanche count peak bn+2 in the shifted histogram. Based on this, after the respective avalanche count peaks at the same time in the original histogram and the shifted histogram are superimposed, the initial superimposed histogram H2 obtained will contain a superimposed avalanche count peak bn+1/n+2 formed by the avalanche count peak bn+1 and the avalanche count peak bn+2. After that, the ranging apparatus may repeatedly perform the above steps S401 to S402 until the avalanche count peaks corresponding to the (bn+1) th to (b 2 n) th encoded pulse signals are superimposed to obtain a first superimposed histogram.

It should be noted that, because the generation interval duration between any two adjacent avalanche count peaks is different, after the steps S401 to S403 are repeatedly performed to superimpose n avalanche count peaks to obtain the first superimposed histogram and the second superimposed histogram, each superimposed histogram will have only one superimposed avalanche count peak that is significantly enhanced. Furthermore, the avalanche count peak value generated by the coded pulse signal returned by the object to be detected can be obviously enhanced, and the avalanche count peak value corresponding to the interfered echo signal can be suppressed.

S103, performing interference elimination processing on the first superimposed histogram and the second superimposed histogram, and generating a target interference-free histogram corresponding to the target pulse signal.

In an embodiment, the first superimposed histogram and the second superimposed histogram are subjected to interference elimination processing, that is, avalanche count peaks generated by echo signals interfering in the first superimposed histogram and the second superimposed histogram are eliminated.

Specifically, referring to fig. 6, fig. 6 is a schematic diagram of an application scenario of a target non-interference histogram in a ranging method according to an embodiment of the present application. In fig. 6, after the above-mentioned interference cancellation process, there will be only one avalanche count peak with a significantly higher peak. Namely, the avalanche count peak value generated by the coded pulse signal returned by the object to be measured is finally overlapped to obtain the overlapped avalanche count peak value after the processing.

As an example, the ranging device may superimpose the first superimposed histogram with the second superimposed histogram to obtain a third superimposed histogram. And meanwhile, subtracting the first superimposed histogram from the second superimposed histogram to obtain a subtracted histogram. And finally, generating a target non-interference histogram based on the third superimposed histogram and the subtraction histogram.

Specifically, the calculation formula for obtaining the target non-interference histogram may be as follows:

H1＝His1+His2-|His1-His2|。

wherein, H1 is the target undisturbed histogram, his1 is the first superimposed histogram, his2 is the second superimposed histogram. That is, the absolute value of the third superimposed histogram and the subtracted histogram are subtracted to generate the target interference-free histogram.

The method of superimposing and subtracting the first superimposed histogram and the second superimposed histogram is similar to the method of generating the first superimposed histogram and the second superimposed histogram, and both the avalanche count peaks at the same time in the two superimposed histograms are superimposed and subtracted.

Specifically, the avalanche count peak value generated by the coded pulse signal returned by the object to be detected is enhanced again, and the avalanche count peak value corresponding to the interfered echo signal is suppressed. When the addition or subtraction processing is performed, the second superimposed histogram may be shifted according to the interval duration between the superimposed avalanche count peak value in the first superimposed histogram and the superimposed avalanche count peak value in the second superimposed histogram, so that the two superimposed avalanche count peak values in the first superimposed histogram and the shifted second superimposed histogram are at the same time. And then, superposing the first superposition histogram and the shifted second superposition histogram to obtain a third superposition histogram, and subtracting to obtain a subtraction histogram.

At this time, after the two superimposed avalanche count peaks are superimposed, the peak will be significantly enhanced in the third superimposed histogram, and after the two avalanche count peaks are subtracted, the peak will not be significantly enhanced in the subtracted histogram. That is, after the third superimposed histogram is subtracted from the subtracted histogram, a new avalanche count peak obtained after the superposition of the significantly enhanced two superimposed avalanche count peaks can be retained in the target non-interference histogram.

It will be appreciated that the subtracted histogram is the absolute value of the subtraction of the peak avalanche count in the first superimposed histogram and the second superimposed histogram. Therefore, when the first superimposed histogram does not have an avalanche count peak or has a smaller peak at time t1, and the second superimposed histogram has an avalanche count peak at time t1 and has a higher avalanche count peak, the subtracted histogram will also have an avalanche count peak (an avalanche count peak corresponding to an interference echo signal) at time t 1. Referring to fig. 7, fig. 7 is a schematic view of an application scenario of a first superimposed histogram and a second superimposed histogram in a ranging method according to an embodiment of the present application. Taking the time t1 as 360ns as an example, under 360ns, the first superimposed histogram has smaller avalanche count peak value in 360ns, and the second superimposed histogram has higher avalanche count peak value in 360 ns. At this time, in the subtracted histogram, there will also be a subtracted avalanche count peak at 360ns time. The avalanche count peak reduction amplitude is low.

And, when the first superimposed histogram has an avalanche count peak (e.g., superimposed avalanche count peak) at time t2, and the second superimposed histogram also has an avalanche count peak (e.g., superimposed avalanche count peak) at time t2, the subtracted histogram will approach 0 at the avalanche count peak at time t 2. For example, referring to fig. 7, where time t2 is 300ns, for example, at 300ns, the first superimposed histogram has an avalanche count peak at 300ns and the second superimposed histogram has an avalanche count peak at 300 ns. At this time, in the subtracted histogram, the avalanche count peak at 300ns time will be significantly reduced.

Based on this, since the third superimposed histogram is obtained by adding the avalanche count peaks in the first superimposed histogram and the second superimposed histogram, the avalanche count peak is present at the time t1 in the first superimposed histogram, and the avalanche count peak is absent or is smaller at the time t1 in the second superimposed histogram, at this time, even if the two avalanche count peaks in the first superimposed histogram and the second superimposed histogram are superimposed, the avalanche count peak present at the time t1 in the third histogram is still smaller. That is, in the third superimposed histogram, there is still one avalanche count peak with a smaller peak at the time of 360ns, so that the avalanche count peak at the time of 360ns cannot be significantly enhanced in the third superimposed histogram.

And when the first superimposed histogram has an avalanche count peak (for example, superimposed avalanche count peak) at time t2, and the second superimposed histogram also has an avalanche count peak (for example, superimposed avalanche count peak) at time t2, then after the avalanche count peaks with higher peaks are superimposed, the avalanche count peak present at time t2 in the third superimposed histogram will be significantly enhanced. That is, in the third superimposed histogram, there will be one superimposed avalanche count peak at 300ns time instant, so that the peak will be significantly enhanced in the subtracted histogram. The avalanche count peak at 300ns time instant will approach the superposition of the avalanche count peaks at 300ns time instant for the first and second superimposed histograms.

Further, when the subtracted histogram is subtracted from the third superimposed histogram, there is one avalanche count peak corresponding to the interference echo signal at time t 1. Thus, after subtraction, the avalanche count peak of the target non-interfering histogram at time t1 will decrease (suppress the avalanche count peak generated by the interfering echo signal). Specifically, referring to fig. 8, fig. 8 is a schematic diagram of an application scenario of a target non-interference histogram in a ranging method according to another embodiment of the present application. Wherein the avalanche count peak at 360ns time instant in the target non-interfering histogram will be lower than the avalanche count peak at 360ns time instant in the second superimposed histogram. That is, in the above-described interference cancellation process, the avalanche count peak generated by the interference echo signal is suppressed.

And the avalanche count peak due to the subtracted histogram at the time t2 approaches 0. Thus, the avalanche count peak of the target non-interfering histogram at the time t2 will be equal to the avalanche count peak of the third superimposed histogram at the time t2 (i.e., the avalanche count peak generated by the encoded pulse signal that enhances the return of the object under test). Specifically, referring to fig. 8, in the target non-interfering histogram, the avalanche count peak at 300ns will approach the superposition of the avalanche count peaks of the first superimposed histogram and the second superimposed histogram at 300 ns. That is, in the above-described interference cancellation process, the avalanche count peak generated by the coded pulse signal returned from the object to be measured is enhanced.

It is added that even if the first superimposed histogram and the second superimposed histogram are subjected to the above-described interference cancellation process, avalanche count peaks generated by interference echo signals that may have the same timing are enhanced. However, the significance of the avalanche count peak generated by the coded pulse signal returned by the object to be detected is far higher than that of the avalanche count peak generated by the interference echo signal after the interference elimination processing is performed on the basis of the enhancement of the step S401-S403.

S104, determining the interval distance between the target non-interference histogram and the object to be detected.

In an embodiment, after the target non-interference histogram is obtained, peak searching (highest avalanche count peak) and centroid solving and pin-up processing may be sequentially performed based on the target non-interference histogram, so as to obtain a distance between the ranging device and the radar. It can be understood that the distance between the ranging device and the object to be measured with the preset azimuth in the corresponding detection space is represented by the distance obtained according to the single target non-interference histogram, so that the distance between the object to be measured with different detection azimuth can be obtained according to the same ranging method, thereby obtaining the depth information of different detection areas of the object to be measured in the detection space, and realizing three-dimensional point cloud imaging through the depth information, thereby realizing three-dimensional information sensing of the object to be measured.

In this embodiment, the ranging apparatus may sequentially transmit the encoded pulse signals to the object to be measured according to the transmission interval duration between 2n encoded pulse signals in the target pulse signal, and receive the returned original histogram with the avalanche count peak value generated by each encoded pulse signal. Where n is required to be 2 or more. And then, according to the generation sequence of each avalanche count peak value and the generation interval duration between two adjacent avalanche count peak values, respectively superposing the avalanche count peak values corresponding to the 1 st to n coding pulse signals and superposing the avalanche count peak values corresponding to the n+1st to 2n coding pulse signals in sequence to obtain a first superposition histogram and a second superposition histogram. Wherein the transmission interval duration between any two adjacent coded pulse signals in the modulated 2n coded pulse signals is different. Therefore, when the two avalanche count peaks in the original histogram are superimposed according to the corresponding emission interval duration (that is, the generation sequence of the avalanche count peaks), each avalanche count peak formed by the optical signal returned by the object to be measured can be superimposed correspondingly based on the emission interval duration. Namely, n avalanche count peaks corresponding to the object to be measured are enhanced in the first superimposed histogram and the second superimposed histogram. However, avalanche count peaks (interference peaks) formed by optical signals returned from a plurality of other non-objects in the original histogram are not spaced apart from each other by a specially set emission interval duration. Therefore, the avalanche count peak corresponding to the non-object to be measured cannot be subjected to peak superposition based on the emission interval duration. That is, in the first superimposed histogram and the second superimposed histogram, the avalanche count peak corresponding to the non-object to be measured cannot be enhanced. Therefore, the interference of the avalanche count peak of the non-object to be measured on the avalanche count peak of the object to be measured can be reduced. Based on the method, the ranging equipment can perform interference elimination based on the first superimposed histogram and the second superimposed histogram corresponding to the enhanced avalanche count peak value to obtain a target interference-free histogram, and accurately determine the interval distance between the ranging equipment and the object to be measured according to the target interference-free histogram. In the ranging process, n coded pulse signals are coded into a group of pulse signal beams for ranging, so that the peak power in the original pulse signal can be equally distributed to 2n coded pulse signals. Furthermore, the need for peak optical power and power consumption of the light source is reduced. And because the transmission interval duration between any two adjacent coded pulse signals in the modulated 2n coded pulse signals is different, the interference between avalanche count peaks can be avoided, and therefore, the transmission interval duration between the two adjacent coded pulse signals can be free from setting longer interval duration. Furthermore, when the distance of a distant object to be measured can be measured, the distance measuring time required to be consumed can be reduced. That is, a more distant ranging performance can be obtained also in the case of a limited ranging time and peak light source power.

It should be noted that the above embodiments of S101 to S104 are a method for ranging according to a target pulse signal transmitted at a time. However, when the above processing is performed based on the target pulse signal transmitted only once, the finally obtained target non-interference histogram may still have more and more significant avalanche count peaks generated by the interference echo signal.

In order to reduce the avalanche count peak generated by the disturbance echo signal as much as possible, the measurement accuracy of the measurement distance is improved. In this embodiment, two target pulse signals may be sent, and the above-described processing of S101 to S103 may be performed on each target pulse signal, respectively, to obtain two target non-interference histograms. That is, the target pulse signal is divided into a first pulse signal and a second pulse signal, and the target non-interference histogram is also divided into a first non-interference histogram corresponding to the first pulse signal and a second non-interference histogram corresponding to the second pulse signal.

At this time, the ranging device may perform interference removing processing on the first non-interference histogram and the second non-interference histogram again to obtain a third non-interference histogram. And then, determining the interval distance between the third non-interference histogram and the object to be detected.

The manner of performing interference elimination on the first non-interference histogram and the second non-interference histogram to obtain the third non-interference histogram is similar to the manner of performing interference elimination on the first superimposed histogram and the second superimposed histogram in the step S103, and will not be described. And determining the separation distance from the third non-interference histogram in a manner similar to that of the step S104, which will not be described.

In another embodiment, in order to further avoid interference between adjacent coded pulse signals in the target pulse signal, when the coded pulse signals are modulated, a duration difference of a transmission interval duration between any two adjacent coded pulse signals may be set to be greater than a preset multiple of a preset signal half-peak width.

In an embodiment, the preset multiple may be set according to practical situations, which is not limited. The preset multiple may be 5 times, for example. The signal half-peak width of the encoded pulse signal can be set in advance by a worker. Further, based on the set signal half-peak width, the worker can set the time length difference of the transmission interval time length between any adjacent two coded pulse signals to be greater than 5 times the signal half-peak width at the time of modulating the coded second pulse signal.

And, in order for the ranging device to be able to have sufficient charge to transmit the next code pulse signal after transmitting one code pulse signal. In this embodiment, the transmission interval time period between any two adjacent coded pulse signals may be set to be longer than the preset time period. Further, after the ranging device transmits a coded pulse signal, the ranging device may fill the discharge capacitance within the ranging device for a sufficient period of time to allow for the next transmission of the coded pulse signal.

The preset time period may be set by a worker according to actual situations, which is not limited. The predetermined duration may be, for example, 40ns or 50ns.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a ranging apparatus according to an embodiment of the present disclosure. The ranging device in this embodiment includes modules for performing the steps in the embodiments corresponding to fig. 1 to 4. Please refer to fig. 1 to fig. 4 and the related descriptions in the embodiments corresponding to fig. 1 to fig. 4. For convenience of explanation, only the portions related to the present embodiment are shown. Referring to fig. 9, the ranging apparatus 900 may include: an execution module 910, a superposition module 920, a generation module 930, and a ranging module 940, where:

An execution module 910, configured to sequentially transmit 2n modulated encoded pulse signals in the target pulse signals to the object to be detected, and sequentially receive each returned encoded pulse signal to generate an original histogram with an avalanche count peak value respectively; the transmission interval duration between each encoded pulse signal is different; n is an integer of 2 or more.

The superposition module 920 is configured to sequentially and respectively superimpose avalanche count peaks corresponding to every n encoded pulse signals according to a generation sequence of each avalanche count peak and a generation interval duration between two adjacent avalanche count peaks, so as to obtain a first superimposed histogram and a second superimposed histogram; the first superposition histogram is obtained by superposing avalanche count peaks from 1 st to n th in the generation sequence; the second superimposed histogram is obtained by superimposing avalanche count peaks of n+1th to 2n in the generation order.

And the generating module 930 is configured to perform interference elimination processing on the first superimposed histogram and the second superimposed histogram, and generate a target non-interference histogram corresponding to the target pulse signal.

And the ranging module 940 is used for determining the interval distance between the target non-interference histogram and the object to be measured.

In an embodiment, the superposition module 920 is further configured to:

Shifting each avalanche count peak value in the original histogram by a target interval duration according to the target interval durations corresponding to the first avalanche count peak value and the adjacent second avalanche count peak value to obtain a shifted histogram with shifted avalanche count peak values; the first avalanche count peak value is an avalanche count peak value which needs to be overlapped at present; superposing all avalanche count peaks in the same time in the original histogram and the shift histogram to obtain an initial superposition histogram; the initial superposition histogram comprises a superposition avalanche count peak value formed by superposition of a first avalanche count peak value and a second avalanche count peak value; and repeatedly executing the steps of obtaining a shift histogram and an initial superposition histogram by taking the initial superposition histogram as a new original histogram and a new first avalanche count peak value of the superposition avalanche count peak value until the avalanche count peak values corresponding to every n coding pulse signals are respectively superposed to obtain a first superposition histogram and a second superposition histogram.

In an embodiment, the generating module 930 is further configured to:

superposing the first superposition histogram and the second superposition histogram to obtain a third superposition histogram; subtracting the first superimposed histogram from the second superimposed histogram to obtain a subtracted histogram; and generating a target interference-free histogram based on the third superimposed histogram and the subtracted histogram.

In an embodiment, the generating module 930 is further configured to:

and subtracting the absolute value of the third superimposed histogram and the absolute value of the subtraction histogram to generate a target interference-free histogram.

In an embodiment, the target pulse signal is divided into a first pulse signal and a second pulse signal, and the target non-interference histogram is divided into a first non-interference histogram corresponding to the first pulse signal and a second non-interference histogram corresponding to the second pulse signal; the ranging module 940 is also configured to:

performing interference elimination processing on the first interference-free histogram and the second interference-free histogram to obtain a third interference-free histogram; and determining the interval distance between the third non-interference histogram and the object to be detected.

In one embodiment, the modulated n encoded pulse signals satisfy the following rule:

the time length difference of the time length of the transmission interval between any two adjacent coded pulse signals is larger than the preset multiple of the half peak width of the preset signal.

In one embodiment, the modulated n encoded pulse signals satisfy the following rule:

the transmission interval time between any two adjacent coded pulse signals is longer than the preset time.

It is to be understood that, in the schematic structural diagram of the ranging device shown in fig. 9, each module is configured to perform each step in the embodiment corresponding to fig. 1 to 4, and each step in the embodiment corresponding to fig. 1 to 4 has been explained in detail in the above embodiment, refer specifically to fig. 1 to 4 and the related description in the embodiment corresponding to fig. 1 to 4, which are not repeated herein.

Fig. 10 is a schematic structural diagram of a ranging apparatus according to an embodiment of the present application. As shown in fig. 10, the ranging apparatus 1000 of this embodiment includes: a processor 1010, a memory 1020, and a computer program 1030 stored in the memory 1020 and executable on the processor 1010, such as a program for a ranging method. The steps of the various embodiments of the ranging method described above, such as S101 through S104 shown in fig. 1, are implemented by processor 1010 when executing computer program 1030. Alternatively, the processor 1010 may implement the functions of each module in the embodiment corresponding to fig. 9 when executing the computer program 1030, for example, the functions of each module shown in fig. 9, and refer to the related description in the embodiment corresponding to fig. 9 specifically.

By way of example, computer program 1030 may be split into one or more modules that are stored in memory 1020 and executed by processor 1010 to implement the ranging methods provided by embodiments of the present application. One or more of the modules may be a series of computer program instruction segments capable of performing particular functions to describe the execution of computer program 1030 in ranging device 1000. For example, computer program 1030 may implement the ranging method provided by embodiments of the present application.

Ranging device 1000 may include, but is not limited to, a processor 1010, a memory 1020. It will be appreciated by those skilled in the art that fig. 10 is merely an example of a ranging device 1000 and is not intended to limit the ranging device 1000, and may include more or fewer components than shown, or may combine certain components, or different components, e.g., a ranging device may also include an input-output device, a network access device, a bus, etc.

The processor 1010 may be a central processing unit, but may also be other general purpose processors, digital signal processors, application specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

Memory 1020 may be an internal storage unit of ranging device 1000, such as a hard disk or memory of ranging device 1000. The memory 1020 may also be an external storage device of the ranging apparatus 1000, such as a plug-in hard disk, a smart memory card, a flash memory card, etc. provided on the ranging apparatus 1000. Further, memory 1020 may also include both internal and external storage units of ranging device 1000.

The present embodiment provides a computer-readable storage medium storing a computer program that is executed by a processor to perform the ranging method in the above embodiments.

Embodiments of the present application provide a computer program product for causing a ranging apparatus to perform the ranging method of the various embodiments described above when the computer program product is run on the ranging apparatus.

The above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims (10)

1. A ranging method, the ranging method comprising:

sequentially transmitting 2n modulated coded pulse signals in the target pulse signals to an object to be detected, and sequentially receiving each returned coded pulse signal to respectively generate an original histogram with an avalanche count peak value; the transmission interval duration between each coded pulse signal is different; n is an integer of 2 or more;

According to the generation sequence of each avalanche count peak value and the generation interval duration between every two adjacent avalanche count peak values, respectively superposing the avalanche count peak values corresponding to every n coding pulse signals in sequence to obtain a first superposition histogram and a second superposition histogram; the first superposition histogram is obtained by superposition of the avalanche count peaks from 1 st to n th in the generation sequence; the second superposition histogram is obtained by superposing the avalanche count peaks of (n+1) th to (2 n) th in the generation sequence;

performing interference elimination processing on the first superimposed histogram and the second superimposed histogram to generate a target non-interference histogram corresponding to the target pulse signal;

and determining the interval distance between the target non-interference histogram and the object to be detected.

2. The ranging method according to claim 1, wherein the sequentially superimposing the avalanche count peaks corresponding to each n encoded pulse signals according to the generation sequence of each avalanche count peak and the generation interval duration between two adjacent avalanche count peaks, to obtain a first superimposed histogram and a second superimposed histogram, includes:

Shifting each avalanche count peak value in the original histogram by the target interval duration according to the target interval duration corresponding to the first avalanche count peak value and the adjacent second avalanche count peak value, and obtaining a shifted histogram with the shifted avalanche count peak value; the first avalanche count peak value is an avalanche count peak value which needs to be overlapped at present;

superposing all avalanche count peaks in the same time in the original histogram and the shift histogram to obtain an initial superposition histogram; the initial superposition histogram comprises a superposition avalanche count peak value formed by superposition of the first avalanche count peak value and the second avalanche count peak value;

and repeating the steps of obtaining the shift histogram and the initial superposition histogram by taking the initial superposition histogram as the new original histogram and the new first avalanche count peak value of the superposition avalanche count peak value until the avalanche count peak values corresponding to every n coding pulse signals are respectively superposed to obtain the first superposition histogram and the second superposition histogram.

3. The ranging method according to claim 1, wherein the performing the interference elimination processing on the first superimposed histogram and the second superimposed histogram to generate the target non-interference histogram corresponding to the target pulse signal includes:

Superposing the first superposition histogram and the second superposition histogram to obtain a third superposition histogram;

subtracting the first superimposed histogram from the second superimposed histogram to obtain a subtracted histogram;

and generating the target interference-free histogram based on the third superimposed histogram and the subtracted histogram.

4. A ranging method as defined in claim 3 wherein said generating said target non-interfering histogram based on said third superimposed histogram and said subtracted histogram comprises:

and subtracting the absolute value of the third superposition histogram and the absolute value of the subtraction histogram to generate the target interference-free histogram.

5. The ranging method according to claim 1, wherein the target pulse signal is divided into a first pulse signal and a second pulse signal, and the target non-interference histogram is divided into a first non-interference histogram corresponding to the first pulse signal and a second non-interference histogram corresponding to the second pulse signal;

the determining the interval distance between the target non-interference histogram and the object to be measured, including:

performing interference elimination processing on the first interference-free histogram and the second interference-free histogram to obtain a third interference-free histogram;

And determining the interval distance between the third non-interference histogram and the object to be detected.

6. Ranging method according to any of claims 1-5, characterized in that the n coded pulse signals modulated fulfil the following rule:

and the time length difference of the time length of the transmission interval between any two adjacent coded pulse signals is larger than the preset multiple of the half peak width of the preset signal.

7. Ranging method according to any of claims 1-5, characterized in that the n coded pulse signals modulated fulfil the following rule:

the transmission interval time length between any two adjacent coded pulse signals is longer than the preset time length.

8. A ranging apparatus, the ranging apparatus comprising:

the execution module is used for sequentially transmitting 2n coded pulse signals modulated in the target pulse signals to an object to be detected, and sequentially receiving each returned coded pulse signal to respectively generate an original histogram with an avalanche count peak value; the transmission interval duration between each coded pulse signal is different; n is an integer of 2 or more;

the superposition module is used for sequentially and respectively superposing the avalanche count peaks corresponding to every n coding pulse signals according to the generation sequence of each avalanche count peak and the generation interval duration between every two adjacent avalanche count peaks to obtain a first superposition histogram and a second superposition histogram; the first superposition histogram is obtained by superposition of the avalanche count peaks from 1 st to n th in the generation sequence; the second superposition histogram is obtained by superposing the avalanche count peaks of (n+1) th to (2 n) th in the generation sequence;

The generating module is used for carrying out interference elimination processing on the first superimposed histogram and the second superimposed histogram and generating a target non-interference histogram corresponding to the target pulse signal;

and the distance measuring module is used for determining the interval distance between the target non-interference histogram and the object to be measured.

9. A ranging apparatus comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the ranging method of any of claims 1 to 7 when the computer program is executed.

10. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the method according to any one of claims 1 to 7.