Distance calculation method, distance measuring system and storage medium

Abstract

The present application relates to a kind of distance calculation method, ranging system and storage medium, the method comprises: periodically injecting random time jitter on the time interval of emission time sequence, so that laser transmitter emits laser pulse according to the emission time after modulation;Based on photoelectric sensor, the laser pulse signal reflected back via target object is received, and the received laser pulse signal is converted into electrical signal;The peak time bin of the statistical histogram of the electrical signal is obtained, the statistical histogram is associated with time bin and the number of times that each time bin corresponds to photoelectric sensor is triggered;According to the peak time bin, the real-time distance value of the target object is calculated.This application effectively improves the discrimination ability of local non-local emission laser pulse or fixed noise, avoids the occurrence of distance calculation error caused by non-local emission laser pulse or fixed noise being same or similar with the pulse of local emission.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser ranging technology, in particular to a distance calculation method and a ranging system. BACKGROUND

[0002] Direct Time Of Flight (DTOF) laser transmitter ranging technology measures the distance information between the transmitter and the object by measuring the round-trip time of the laser. DTOF laser transmitter has many advantages such as simple and compact structure, wide application range, fast speed and high precision. The accuracy of DTOF depends on the duration of the pulse, so its measurement accuracy and anti-interference ability will not decrease significantly with the increase of distance, the error of measuring different distances is small, and it can capture relatively high-precision, low-noise and high-credibility depth information even when the measured object is far away.

[0003] However, when multiple laser transmitters are used in the same scene and at least two laser transmitters use single-pulse laser emission, the emitted single laser pulse is the same, which may cause the local machine to calculate the distance of the object to be measured according to the received non-local emitted laser pulse, thereby reducing the accuracy of distance measurement. SUMMARY

[0004] Therefore, it is necessary to provide a distance calculation method and a ranging system to effectively improve the discrimination ability of the local machine to non-local emitted laser pulses and avoid the occurrence of distance calculation errors caused by non-local emitted laser pulses being the same as or similar to local emitted pulses.

[0005] To achieve the above object and other objects, one aspect of the present application provides a distance calculation method, comprising:

[0006] periodically injecting random time jitter on the time interval of the emission time sequence, so that the laser transmitter emits a laser pulse according to the modulated emission time;

[0007] receiving the laser pulse signal reflected by the target object through the optical-electric sensor and converting the received laser pulse signal into an electric signal, wherein the optical-electric sensor comprises a plurality of pixels;

[0008] obtaining the peak time bin of the statistical histogram of the electric signal, wherein the statistical histogram is associated with the time bin and the number of times the corresponding optical-electric sensor is triggered in each time bin;

[0009] calculating the real-time distance value of the target object according to the peak time bin.

[0010] In the distance calculation method in the above embodiments, a transmission time sequence is formed according to fixed transmission times of the laser transmitter, random time jitter is periodically injected on time intervals of the transmission time sequence, so that the laser transmitter transmits laser pulses according to the modulated transmission times, the photoelectric sensor receives the laser pulse signals reflected back by the target object and converts the received laser pulse signals into electrical signals, the photoelectric sensor includes a plurality of pixels, then a peak time bin of a statistical histogram of the electrical signals is obtained, the statistical histogram is associated with time bins and the number of times that the photoelectric sensor is triggered for each time bin, and the real-time distance value of the target object is calculated according to the peak time bin. Since the laser transmitter transmits laser pulses according to the modulated transmission times multiple times by periodically injecting random time jitter on time intervals of the transmission time sequence, the synchronization of the reception times of the local transmission laser pulse echo and the non-local transmission laser pulse echo or the fixed noise echo is destroyed, the energy of the non-local or fixed noise is uniformly scattered in the range of the photoelectric sensor, the non-local transmission laser pulse or the fixed noise reception echo is eliminated on the statistical histogram to raise the noise floor, the situation of multiple peaks appearing on the statistical histogram is avoided, the discrimination ability of the local and non-local transmission laser pulses is effectively improved, and the situation of distance calculation error caused by the non-local transmission laser pulse being the same as or similar to the local transmission pulse is avoided. Compared with injecting random time jitter at the moment of each transmission of the laser transmitter, periodically injecting random time jitter on time intervals of the transmission time sequence can improve the efficiency of the photoelectric sensor in receiving laser pulse echoes, improve the signal-to-noise ratio of the statistical histogram, and further improve the accuracy of distance calculation.

[0011] In one of the embodiments, the injected random time jitter is pseudo-random time jitter.

[0012] In one of the embodiments, the duration Δt of the pseudo-random time jitter is less than one transmission period T of the laser pulse, where T = 1 / f, and f is the transmission frequency of the laser transmitter.

[0013] In one of the embodiments, the duration Δt of the pseudo-random time jitter ranges from 1 ns to 3 ns.

[0014] In one of the embodiments, the step of periodically injecting random time jitter on time intervals of the transmission time sequence further includes:

[0015] The injection period N of the random time jitter is set so that a random time jitter Δt is injected every N*T transmission times, and N ranges from 1 to 100.

[0016] In one of the embodiments, the injection period N of the random time jitter decreases as the emission frequency f of the laser emitter increases.

[0017] In one of the embodiments, the step of obtaining the peak time bin of the statistical histogram of the electrical signal comprises:

[0018] According to the number of times the photoelectric sensor is triggered in the nth time bin, a statistical histogram S m (n) is obtained, where m is the time bin, n is the number of times the photoelectric sensor is triggered, and m and n are positive integers.

[0019] If S i (n) ≥ S i-1 (n), and S i (n) ≥ S i+1 (n), then i is the peak time bin, and i ∈ [1, m].

[0020] Another aspect of the present application provides a computer readable storage medium having a computer program stored thereon, the computer program being executed by a controller to implement the distance calculation method described in any of the embodiments of the present application.

[0021] Still another aspect of the present application provides a ranging system, comprising a laser emitter, a photoelectric sensor, and a controller, the laser emitter being configured to emit a laser pulse signal; the photoelectric sensor being configured to receive the laser pulse signal reflected by a target object and convert the received laser pulse signal into an electrical signal, wherein the photoelectric sensor comprises a plurality of pixels; the controller being connected to the laser emitter and the photoelectric sensor, and being configured to periodically inject a random time jitter over a time interval of a time sequence to control the laser emitter to emit a laser pulse according to a modulated emission time; obtain a peak time bin of a statistical histogram of the electrical signal, the statistical histogram being associated with a time bin and a number of times the photoelectric sensor is triggered in each time bin; and calculate a real-time distance value of the target object according to the peak time bin.

[0022] In the computer readable storage medium or the distance measuring system in the above embodiments, a sequence of emission times is formed according to the fixed emission times of the laser emitter, random time jitter is periodically injected on the time interval of the sequence of emission times, so that the laser emitter emits laser pulses according to the modulated emission times, the photoelectric sensor receives the laser pulse signals reflected by the target object and converts the received laser pulse signals into electrical signals, the photoelectric sensor includes a plurality of pixels, then the peak time bin of the statistical histogram of the electrical signals is obtained, the statistical histogram is associated with the time bins and the number of times that the photoelectric sensor is triggered for each time bin, and the real-time distance value of the target object is calculated according to the peak time bin. Since the laser emitter emits laser pulses according to the modulated emission times multiple times by periodically injecting random time jitter on the time interval of the sequence of emission times, the synchronization of the echo reception time of the locally emitted laser pulse and the non-locally emitted laser pulse or the fixed noise echo is destroyed, the energy of the non-locally emitted laser pulse or the fixed noise echo is uniformly scattered in the range of the photoelectric sensor, the non-locally emitted laser pulse or the fixed noise echo is eliminated on the statistical histogram, the noise floor is raised, the situation that multiple peaks appear on the statistical histogram is avoided, the discrimination ability of the locally emitted laser pulse and the non-locally emitted laser pulse is effectively improved, and the situation that the distance calculation is wrong due to the same or similar laser pulses is avoided. Compared with injecting random time jitter at the moment when the laser emitter emits a laser pulse each time, periodically injecting random time jitter on the time interval of the sequence of emission times can improve the efficiency of the photoelectric sensor in receiving the laser pulse echo, improve the signal-to-noise ratio of the statistical histogram, and further improve the accuracy of distance calculation.

[0023] In one of the embodiments, the controller is further configured to set the injection period N of the random time jitter, wherein the value range of N is 1-100, the injection period N of the random time jitter decreases as the emission frequency f of the laser emitter increases, and the duration Δt of the random time jitter is less than a emission period T of the laser pulse, wherein T=1 / f, and f is the emission frequency of the laser emitter. By setting the duration Δt of the random time jitter to be less than the emission period T of the laser pulse, the random time jitter is not injected at the moment when the laser emitter emits a laser pulse each time, the efficiency of the photoelectric sensor in receiving the laser pulse echo is improved, the signal-to-noise ratio of the statistical histogram is improved, and the accuracy of distance calculation is further improved. By setting the injection period N of the random time jitter, wherein the value range of N is 1-100, and the injection period N of the random time jitter decreases as the emission frequency f of the laser emitter increases, the situation that the energy of the injected random time jitter is too high to submerge the peak corresponding to the laser pulse echo on the statistical histogram is avoided. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating a distance calculation method provided in one embodiment of this application;

[0026] Figure 2 This is a schematic diagram of the waveform curves of the electrical signals acquired by the machine from multiple laser emitters in the same application scenario.

[0027] Figure 3 This is a schematic diagram of the structure of a ranging system provided in one embodiment of this application;

[0028] Figure 4 for Figure 3 The diagram shows a partial structural schematic of the ranging system shown. Detailed Implementation

[0029] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0031] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0032] In the present application, unless specifically defined and limited otherwise, the terms "mounting", "connected", "connection", "fixed", and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] Please refer to Figure 1 In an embodiment of the present application, a distance calculation method is provided, comprising:

[0034] Step S110, periodically injecting random time jitter on the time interval of the emission time sequence, so that the laser emitter emits laser pulses according to the modulated emission time;

[0035] Step S120, receiving the laser pulse signal reflected back via the target object based on the photoelectric sensor, and converting the received laser pulse signal into an electrical signal, wherein the photoelectric sensor comprises a plurality of pixels;

[0036] Step S130, obtaining the peak time bin of the statistical histogram of the electrical signal, the statistical histogram being associated with the time bin and the number of times the photoelectric sensor corresponding to each time bin is triggered;

[0037] Step S140, calculating the real-time distance value of the target object according to the peak time bin.

[0038] Specifically, please continue to refer to Figure 1, according to the fixed emission time of the laser emitter, a sequence of emission times is formed, a random time jitter is periodically injected on the time interval of the sequence of emission times, so that the laser emitter emits laser pulses according to the modulated emission times, the photoelectric sensor receives the laser pulse signals reflected back via the target object and converts the received laser pulse signals into electrical signals, wherein the photoelectric sensor includes a plurality of pixels, then the peak time bin of the statistical histogram of the electrical signals is obtained, the statistical histogram is associated with the time bin and the number of times the photoelectric sensor is triggered corresponding to each time bin, and the real-time distance value of the target object is calculated according to the peak time bin. Since the laser emitter emits laser pulses according to the modulated emission times multiple times by periodically injecting a random time jitter on the time interval of the sequence of emission times, the synchronization of the received time of the echo of the locally emitted laser pulse and the echo of the non-locally emitted laser pulse or the fixed noise echo is destroyed, the energy of the non-locally emitted or fixed noise is uniformly scattered in the range of the photoelectric sensor, thereby eliminating the non-locally emitted laser pulse or the fixed noise echo on the statistical histogram and raising the noise floor, avoiding the occurrence of multiple peaks on the statistical histogram, thereby effectively improving the discrimination ability of the locally emitted laser pulse and the non-locally emitted laser pulse, and avoiding the occurrence of distance calculation errors caused by the non-locally emitted laser pulse being the same as or similar to the locally emitted pulse. Compared with injecting a random time jitter at the moment of each emission of the laser emitter, periodically injecting a random time jitter on the time interval of the sequence of emission times can improve the efficiency of the photoelectric sensor in receiving the laser pulse echo, improve the signal-to-noise ratio of the statistical histogram, and further improve the accuracy of distance calculation.

[0039] More specifically, please refer to Figure 2 During the shooting of the same target object by the laser emitter 1, the laser emitter 2 (local) and the laser emitter 3 emitting laser pulses of the same frequency and amplitude, since the single laser pulse emitted by the laser emitter 1, the laser emitter 2 (local) and the laser emitter 3 is the same, the photoelectric sensor in the laser emitter 2 (local) receives the laser pulse echo emitted by other laser emitters, and obtains an electrical signal as shown in Figure 2 Since the local cannot distinguish Figure 2The peak value of the three peaks is the echo of the local laser pulse, which causes the distance calculation error. Therefore, a transmission time sequence is formed according to the fixed transmission time of the laser transmitter, a random time jitter is periodically injected on the time interval of the transmission time sequence, so that the laser transmitter transmits a laser pulse according to the modulated transmission time, and the injected random time jitter is a pseudo-random time jitter; for example, the duration Δt of the injected pseudo-random time jitter is less than one transmission period T of the laser pulse, where T = 1 / f, and f is the transmission frequency of the laser transmitter, wherein the duration Δt of the pseudo-random time jitter ranges from 1ns to 3ns, for example, the duration Δt of the pseudo-random time jitter ranges from 1ns, 2ns or 3ns, to avoid the duration Δt of the pseudo-random time jitter being too large to affect the detection efficiency of the photoelectric sensor.

[0040] As an example, if one transmission period T of the laser transmitter is 40ns, a pseudo-random time jitter can be inserted every 320ns on the time interval of the transmission time sequence, and the pseudo-random time jitter does not include negative values to avoid inserting negative values to reduce the range of the photoelectric sensor. By periodically injecting random time jitter on the time interval of the transmission time sequence, the laser transmitter transmits a laser pulse according to the modulated transmission time multiple times, destroys the synchronization of the echo of the local laser pulse with the echo of the non-local laser pulse or the fixed noise echo, and uniformly scatters the energy of the non-local or fixed noise within the range of the photoelectric sensor, thereby eliminating the echo of the non-local laser pulse or the fixed noise on the statistical histogram and raising the noise floor, obtaining a statistical histogram that can accurately determine the peak time bin of the echo of the local laser pulse, avoiding the occurrence of multiple peaks on the statistical histogram, thereby effectively improving the discrimination ability of the local laser pulse from the non-local laser pulse, and avoiding the occurrence of distance calculation errors caused by the non-local laser pulse being the same as or similar to the local laser pulse. Compared with injecting random time jitter at the moment of transmitting a laser pulse by the laser transmitter each time, the present application periodically injects random time jitter on the time interval of the transmission time sequence, which can improve the efficiency of the photoelectric sensor receiving the laser pulse echo, improve the signal-to-noise ratio of the statistical histogram, and further improve the accuracy of distance calculation. As an example, before the step of periodically injecting random time jitter on the time interval of the transmission time sequence, the injection period N of the random time jitter is set to be N*T, so that a random time jitter Δt is injected every N*T transmission time, wherein N ranges from 1 to 100. Avoiding the situation that the energy of the injected random time jitter is too high to drown out the peak corresponding to the laser pulse echo on the statistical histogram; also avoiding the situation that the energy of the injected random time jitter is too low to effectively eliminate the echo of the non-local laser pulse or the fixed noise echo on the statistical histogram.

[0041] As an example, the injection period N of the random time jitter can be set to decrease as the emission frequency f of the laser emitter increases. For example, when the emission frequency f of the laser emitter is 10M, the injection period N of the random time jitter can be set to 64; when the emission frequency f of the laser emitter is 25M, the injection period N of the random time jitter can be set to 16; and when the emission frequency f of the laser emitter is 50M, the injection period N of the random time jitter can be set to 8. The embodiment can avoid the situation that the statistical histogram is submerged by the energy of the injected random time jitter, so that the injection period of the random time jitter can meet the ranging requirements of different laser emitters with different emission frequencies, and the accuracy of ranging is improved.

[0042] As an example, the step of obtaining the peak time bin of the statistical histogram of the electrical signal in step S130 comprises:

[0043] According to the number of triggers of the photoelectric sensor in the nth time bin, the statistical histogram S m (n) is obtained, where m is the time bin, n is the number of triggers of the photoelectric sensor, and m and n are positive integers;

[0044] If S i (n) ≥ S i-1 (n), and S i (n) ≥ S i+1 (n), then i is the peak time bin, and i ∈ [1, m].

[0045] By obtaining the peak value and the corresponding time bin of the statistical histogram, the real-time distance value of the target object can be calculated according to the peak time bin.

[0046] Please refer to Figure 3In an embodiment of the present application, a ranging system 200 is provided, comprising a laser emitter 201, a photoelectric sensor 202 and a controller 203, the laser emitter 201 is configured to emit a laser pulse signal; the photoelectric sensor 202 is configured to receive the laser pulse signal reflected by a target object and convert the received laser pulse signal into an electrical signal, wherein the photoelectric sensor 202 comprises a plurality of pixels; the controller 203 is connected with the laser emitter 201 and the photoelectric sensor 202, and is configured to periodically inject random time jitter on a time interval of a time sequence of emission to control the laser emitter 201 to emit a laser pulse according to a modulated emission time; obtain a peak time bin of a statistical histogram of the electrical signal, the statistical histogram is associated with a time bin and a number of times that the photoelectric sensor corresponding to each time bin is triggered; and calculate a real-time distance value of the target object according to the peak time bin. Since the present application periodically injects random time jitter on a time interval of a time sequence of emission, the laser emitter 201 emits a laser pulse according to a modulated emission time multiple times, which destroys the synchronization of the receiving time of the echo of the locally emitted laser pulse and the echo of the non-locally emitted laser pulse or the fixed noise echo, and uniformly scatters the energy of the non-locally emitted or fixed noise in the range of the photoelectric sensor, thereby eliminating the echo of the non-locally emitted laser pulse or the fixed noise on the statistical histogram and raising the noise floor, avoiding the occurrence of multiple peaks on the statistical histogram, thereby effectively improving the discrimination ability of the locally emitted laser pulse and the non-locally emitted laser pulse, and avoiding the occurrence of distance calculation errors caused by the non-locally emitted laser pulse being the same as or similar to the locally emitted pulse. Compared with injecting random time jitter at the moment of each emission of the laser emitter 201, the present application periodically injects random time jitter on a time interval of a time sequence of emission, which can improve the efficiency of the photoelectric sensor in receiving the laser pulse echo, improve the signal-to-noise ratio of the statistical histogram, and further improve the accuracy of distance calculation.

[0047] As an example, please continue to refer to Figure 3The controller 203 is further configured to set an injection period N of the random time jitter, wherein N is in a range of 1-100, for example, N is 1, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100, the injection period N of the random time jitter decreases as the emission frequency f of the laser emitter increases, and a duration At of the random time jitter is less than a transmission period T of the laser pulse, wherein T = 1 / f, and f is the emission frequency of the laser emitter. By setting the duration At of the random time jitter to be less than the transmission period T of the laser pulse, the efficiency of the photoelectric sensor in receiving the laser pulse echo is improved, the signal-to-noise ratio of the statistical histogram is improved, and the accuracy of the distance calculation is further improved. By setting the injection period N of the random time jitter, wherein N is in a range of 1-100, and the injection period N of the random time jitter decreases as the emission frequency f of the laser emitter increases, the situation that the energy of the injected random time jitter is too high to submerge the wave peak corresponding to the laser pulse echo on the statistical histogram is avoided.

[0048] As an example, refer to Figure 4 The photoelectric sensor 202 includes a single photon avalanche diode array (SPAD) 11 and a time-to-digital converter (TDC) 12. The TDC 12 is connected to the SPAD 11 and is configured to receive the laser pulse signal reflected by the target object and calculate the number of times the SPAD array is triggered by the received optical signal to generate an electrical signal, so that the controller 203 can obtain the rising edge time bin of the continuous increment curve according to the electrical signal and calculate the real-time distance value of the target object according to the rising edge time bin. In this embodiment, the SPAD array 11 is preferably arranged in a uniform array. The SPAD is a binary device that is biased at a voltage close to avalanche. A small amount of carriers excited by a weak optical signal are multiplied in number through a field close to avalanche due to collision ionization, thereby obtaining a larger electrical signal. Therefore, the SPAD has only two states of "output signal" and "no output signal". In this embodiment, the TDC 12 is used to record the number of times the SPAD array 11 is triggered, so as to convert the received optical signal including the laser pulse signal reflected by the target object into an electrical signal.

[0049] The ranging system described in the examples of the present application can be applied to mobile phones, tablets, smart bracelets or smart wearable products, and has the advantages of small size, stable performance, strong anti-interference ability, fast measurement speed and high measurement accuracy.

[0050] Further, in an embodiment of the present application, a computer readable storage medium is provided, and a computer program is stored on the computer readable storage medium, and the computer program is executed by a controller to implement the distance calculation method described in any embodiment of the present application.

[0051] In the computer readable storage medium in the above embodiment, a transmission time sequence is formed according to the fixed transmission time of the laser transmitter, random time jitter is periodically injected on the time interval of the transmission time sequence, so that the laser transmitter transmits laser pulses according to the modulated transmission time, the photoelectric sensor receives the laser pulse signals reflected back by the target object, and converts the received laser pulse signals into electrical signals, wherein the photoelectric sensor includes a plurality of pixels, then the peak time bin of the statistical histogram of the electrical signals is obtained, the statistical histogram is associated with the time bin and the number of times that the photoelectric sensor corresponding to each time bin is triggered, and the real-time distance value of the target object is calculated according to the peak time bin. Since the present application periodically injects random time jitter on the time interval of the transmission time sequence, so that the laser transmitter transmits laser pulses according to the modulated transmission time multiple times, the synchronization of the received time of the local transmitted laser pulse echo and the non-local transmitted laser pulse echo or the fixed noise echo is destroyed, the energy of the non-local or fixed noise is uniformly scattered in the range of the photoelectric sensor, thereby eliminating the non-local transmitted laser pulse or the fixed noise received echo on the statistical histogram and raising the noise floor, avoiding the situation that multiple peaks appear on the statistical histogram, thereby effectively improving the discrimination ability of the local and non-local transmitted laser pulses, and avoiding the situation that the distance calculation is wrong due to the same or similar non-local transmitted laser pulses and local transmitted pulses. Compared with injecting random time jitter at the moment of transmitting the laser pulse by the laser transmitter each time, the present application periodically injects random time jitter on the time interval of the transmission time sequence, which can improve the efficiency of the photoelectric sensor receiving the laser pulse echo, improve the signal-to-noise ratio of the statistical histogram, and further improve the accuracy of the distance calculation.

[0052] It should be understood that, although Figure 1 The steps in the flowchart of the present application are displayed in sequence according to the direction of the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, Figure 1At least one of the steps in the above-mentioned embodiments can include a plurality of sub-steps or a plurality of stages, which are not necessarily performed at the same time, but can be performed at different times, and the order of the execution of the sub-steps or stages is not necessarily sequential, but can be performed alternately or alternately with at least one of the other steps or the sub-steps or stages of the other steps.

[0053] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of the method. Any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0054] Any combination of the technical features of the above-mentioned embodiments can be combined. In order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0055] The above-mentioned embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A distance calculation method characterized by, The method comprises the following steps: periodically injecting a pseudo-random time jitter without negative values on the time interval of the emission time sequence, so that the laser emitter emits laser pulses according to the modulated emission time; the duration Δt of the pseudo-random time jitter is less than one emission period T of the laser pulses, wherein T = 1 / f, and f is the emission frequency of the laser emitter; the value range of the Δt is 1ns-3ns; before the step of periodically injecting a random time jitter on the time interval of the emission time sequence, the injection period N of the pseudo-random time jitter is set, so that a pseudo-random time jitter Δt is injected every N*T emission time, wherein the value range of N is 1-100; the injection period N of the pseudo-random time jitter decreases with the increase of the emission frequency f of the laser emitter; receiving the laser pulse signal reflected back via the target object based on the photoelectric sensor, and converting the received laser pulse signal into an electrical signal, wherein the photoelectric sensor comprises a plurality of pixels; obtaining a peak time bin of a statistical histogram of the electric signal, the statistical histogram being associated with time bins and a number of times that a photoelectric sensor corresponding to each time bin is triggered; wherein the statistical histogram S m (n) is obtained according to the number of times that the photoelectric sensor is triggered in an nth time bin, m is a time bin, n is the number of times that the photoelectric sensor is triggered, and m and n are positive integers; if S i (n)≥S i-1 (n), and S i (n)≥S i+1 (n), then i is the peak time bin, and i∈[1, m]. calculating the real-time distance value of the target object according to the peak time box.

2. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the controller to realize the steps of the method of claim 1.

3. A ranging system characterized by, The method comprises the following steps: a laser emitter for emitting a laser pulse signal; a photoelectric sensor for receiving the laser pulse signal reflected back via the target object and converting the received laser pulse signal into an electrical signal, wherein the photoelectric sensor comprises a plurality of pixels; a controller connected with the laser emitter and the photoelectric sensor, and configured to: periodically inject a pseudo-random time jitter without negative values on the time interval of the emission time sequence to control the laser emitter to emit laser pulses according to the modulated emission time; the duration Δt of the pseudo-random time jitter is less than one emission period T of the laser pulses, wherein T = 1 / f, and f is the emission frequency of the laser emitter; the value range of the Δt is 1ns-3ns; before the step of periodically injecting a pseudo-random time jitter on the time interval of the emission time sequence, the injection period N of the pseudo-random time jitter is set, so that a pseudo-random time jitter Δt is injected every N*T emission time, wherein the value range of N is 1-100; the injection period N of the pseudo-random time jitter decreases with the increase of the emission frequency f of the laser emitter; obtaining a peak time bin of a statistical histogram of the electric signal, the statistical histogram being associated with time bins and a number of times that a photoelectric sensor corresponding to each time bin is triggered; wherein the statistical histogram S m (n) is obtained according to the number of times that the photoelectric sensor is triggered in an nth time bin, m is a time bin, n is the number of times that the photoelectric sensor is triggered, and m and n are positive integers; if S i (n)≥S i-1 (n), and S i (n)≥S i+1 (n), then i is the peak time bin, and i∈[1, m]. calculating the real-time distance value of the target object according to the peak time box.

Images