WO2023071908A1 - 一种测距方法和测距系统 - Google Patents

一种测距方法和测距系统 Download PDF

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WO2023071908A1
WO2023071908A1 PCT/CN2022/126423 CN2022126423W WO2023071908A1 WO 2023071908 A1 WO2023071908 A1 WO 2023071908A1 CN 2022126423 W CN2022126423 W CN 2022126423W WO 2023071908 A1 WO2023071908 A1 WO 2023071908A1
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ranging
sequence
spad
distance measurement
pulse signals
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PCT/CN2022/126423
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English (en)
French (fr)
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雷述宇
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宁波飞芯电子科技有限公司
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Publication of WO2023071908A1 publication Critical patent/WO2023071908A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/4865—Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak

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  • the present application relates to the field of distance measurement, and more specifically, to a distance measurement method and a distance measurement system.
  • time-of-flight (TOF) imaging has put forward an urgent demand.
  • Time of flight (TOF) the principle is to continuously send light pulses to the target, and then use the sensor to receive the light returned from the object, and obtain the target distance by detecting the flight (round-trip) time of the light pulse .
  • Direct Time of Flight is a kind of TOF.
  • DTOF technology directly obtains the target distance by calculating the emission and reception time of light pulses. It has simple principle, good signal-to-noise ratio, high sensitivity, and high accuracy. advantages, has received more and more attention.
  • the traditional pulse laser encoding method has anti-interference performance, it directly performs statistics after receiving, which brings great complexity to the subsequent processing circuit. At the same time, it also requires a large amount of storage overhead. Therefore, it is necessary to propose a A ranging method and ranging system with anti-interference performance that can save storage space.
  • the present application provides a ranging method and a ranging system, so as to solve the defect of large storage overhead caused by solving the interference problem in the prior art.
  • the embodiment of the present application provides a ranging method, including:
  • the moving time window convolution calculation is performed on the sequence A and the sequence B, and a ranging result is obtained according to the calculation result.
  • the N pulse signals are generated by random numbers.
  • time intervals between adjacent pulses of the N pulse signals are random.
  • the time interval between adjacent pulses of the N pulses is proportional to the dead time of the SPAD.
  • the number of the N pulses is proportional to the ranging range.
  • the embodiment of the present application provides a ranging system, including:
  • a transmitting module configured to transmit N pulse signals
  • a receiving module configured to receive an echo signal, wherein the receiving module includes a SPAD device for detecting an optical signal, and the echo signal triggers the SPAD avalanche;
  • a storage module configured to store the N pulse signals and their emission times to form a sequence A, and the moment when the SPAD is triggered to form a sequence B;
  • the calculation module performs moving time window convolution calculation according to the sequence A and the sequence B, and obtains a ranging result according to the calculation result.
  • the N pulse signals are generated by random numbers.
  • time intervals between adjacent pulses of the N pulse signals are random.
  • the time interval between adjacent pulses of the N pulses is proportional to the dead time of the SPAD.
  • the number of the N pulses is proportional to the ranging range.
  • Embodiments of the present application provide a ranging method and a ranging system, which improve the anti-interference performance of equipment compared with traditional ranging methods and ranging systems.
  • the ranging system and ranging method proposed in this application have higher precision than traditional ranging methods and ranging systems.
  • the state of SPAD can be directly represented by binary numbers 0 or 1, which saves more storage space than APD. That is to say, after digitizing with SPAD devices, the ranging system can reduce the amount of data and support more parallel processing The number of channels supports larger arrays.
  • Fig. 1 is a kind of schematic diagram of traditional detection system
  • Fig. 2 is a histogram of ranging results obtained by adopting a traditional detection system
  • FIG. 3 is a flow chart of a ranging method provided in an embodiment of the present application.
  • Fig. 4 is a module block diagram of a ranging system provided by an embodiment of the present application.
  • Time of flight the principle is to continuously send light pulses to the target, and then use the sensor to receive the light returned from the object, and obtain the target distance by detecting the flight (round-trip) time of the light pulse .
  • Direct Time of Flight is a kind of TOF.
  • DTOF technology directly obtains the target distance by calculating the emission and reception time of light pulses. It has simple principle, good signal-to-noise ratio, high sensitivity and accuracy. Higher merits have received more and more attention.
  • a photodetector array including a single photon detector can be used to perform the task of photodetection .
  • One or more photodetectors may define detector pixels of the array.
  • SPAD arrays can be used as solid-state photodetectors in imaging applications that may require high sensitivity and timing resolution.
  • SPADs are based on semiconductor junctions (e.g., p-n junctions) that can detect incident photons when biased outside of their breakdown region by, for example, passing or in response to a strobe signal with a desired pulse width.
  • a high reverse bias voltage generates an electric field of sufficient magnitude that a single charge carrier introduced into the depletion layer of the device can cause a self-sustained avalanche through impact ionization.
  • DTOF technology overcomes the difficulties of photoelectric detection technology and realizes single photon detection.
  • the distance is measured directly based on the time difference between pulse transmission and reception.
  • the electronic clock is activated.
  • the beam steering unit steers the pulses into the desired direction.
  • the pulses are reflected from the detection target and partly received by the photodetector.
  • a photodetector connected to the front-end electronics generates an electrical signal, which asserts the clock.
  • FIG. 1 is a schematic diagram of a traditional detection system
  • FIG. 2 is a histogram, ie, a histogram, of ranging results obtained by using the traditional detection system.
  • the processing unit 120 controls the light source 110 to emit light, where the light source may be an LED or a laser source.
  • the light source is generally selected as a laser source with a near-infrared wavelength, and the laser source can be a VSCEL array laser source, which is not limited here.
  • the receiving module 130 includes a SPAD single photon avalanche diode detection unit, which can achieve accurate detection of weak energy.
  • the light source emits a pulsed laser with a certain pulse width, such as a few nanoseconds, and the final target distance information is obtained from the statistical results through tens of thousands of times of emission.
  • the pulsed laser light is reflected by the detection target 140, and then returns to the array type receiving module in the avalanche state SPAD, wherein the detection unit in the avalanche state can receive the returned signal, and the returned signal can be the echo of the emitted pulsed beam and form a photon signal .
  • the SPAD unit of the receiving module When the SPAD of the receiving module is applied with a high bias voltage, the SPAD unit of the receiving module is in an avalanche state, so it can sense background light or photons of returning signal light, and then use the statistical function of the processing module to perform a large number of trigger events Statistics, constructing a histogram through statistical results, for example, as shown in FIG. 2 .
  • the acquisition of the distance information of the detection target 140 can be realized by outputting the time period information with a high trigger probability of the histogram.
  • the present application proposes a ranging method and a ranging system.
  • FIG. 3 it is a flow chart of a ranging method provided by the present application. The specific steps of the ranging method provided by the present application will be described in detail below.
  • the ranging system includes a transmitting module and a receiving module.
  • the transmitting module is used to transmit detection signals
  • the receiving module is used to receive echo signals and process them to obtain distance information.
  • the transmitting module transmits N pulse signals.
  • the pulse interval of the pulse signal is not a fixed value, but can be a random value.
  • N can be 1024, that is, a detection transmits 1024 pulses.
  • the average pulse interval is about 10 ns, and the interval is divided into 8ns and 12ns.
  • the N pulse signals emitted in the previous step S1 are stored in the storage module in the circuit to form sequence A.
  • the pulse interval of 8ns represents 0, and the pulse interval of 12ns represents 1, which will generate a pseudo-random sequence with a length of 1024 numbers and store it in the storage module .
  • the receiving module receives the echo signal, and the echo signal can cause an avalanche of the SPAD device in the receiving module to generate an avalanche signal, and the avalanche signal is used to record whether the SPAD is triggered.
  • the SPAD When the receiving module receives the echo signal, the SPAD is triggered, and the storage module records the moment when the SPAD is triggered, and records and stores the moment.
  • setting the time of one detection cycle as 11600ns covers the flight time of 1333.33ns, corresponding to the ranging of 200m, and the time of 10240ns occupied by 1024 light pulses.
  • the time precision is set to 1ns, and records whether the SPAD is triggered, 0 means that the SPAD is triggered, 1 means that the SPAD is not triggered, and the recording ends at 11600ns of a detection cycle.
  • the moving window convolution is performed, and the moving window time is 0-1333ns, which represents the range of 0-200m.
  • ⁇ t minimum time
  • the convolution operation is as follows:
  • the echo time is m ns.
  • the time is converted into distance, and the detection distance can be obtained directly.
  • the ranging method provided in the present application can be applied in a scenario where multiple measuring devices work simultaneously, and improves the anti-interference performance of the devices.
  • the ranging system and ranging method proposed in this application have higher precision than traditional ranging devices.
  • the state of SPAD can be directly represented by binary numbers 0 or 1, which saves more storage space than APD. That is to say, after digitizing with SPAD devices, the ranging system can reduce the amount of data and support more parallel processing The number of channels supports larger arrays.
  • the present application also provides a ranging system, as shown in FIG. 4 , including a transmitting module 401 , a receiving module 402 , a storage module 403 , and a calculating module 405 .
  • the transmitting module 401 is used for transmitting N pulse signals.
  • the pulse interval of the pulse signal is not a fixed value, but can be a random value.
  • N can be 1024, that is, 1024 pulses are emitted in one detection, and the average pulse interval is about 10 ns, and the interval is divided into 8 ns and 12 ns.
  • the receiving module 402 includes a SPAD device, and the SPAD is used for detecting optical signals.
  • the receiving module 402 receives the echo signal, and the echo signal can cause an avalanche of the SPAD device in the receiving module to generate an avalanche signal, which is used to record whether the SPAD is triggered.
  • the SPAD When the receiving module 402 receives the echo signal, the SPAD is triggered, and the storage module 403 records the time when the SPAD is triggered, records and stores the time, and forms sequence B.
  • the storage module 403 is also used for storing the sequence A of the transmitted N pulse signals.
  • Calculation module 405 configured to perform moving time window convolution calculation according to sequence A and sequence B, and obtain a ranging result according to the calculation result.

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Abstract

一种测距方法和测距系统，该测距方法包括：发射N个脉冲信号；存储N个脉冲信号及其发射时间，形成序列A；接收回波信号，回波信号触发SPAD雪崩；存储SPAD被触发的时刻，形成序列B；对序列A与序列B进行移动时间窗口卷积计算，并根据计算结果得到测距结果。该测距方法和测距系统提高了测距系统的抗干扰性能，并且因为SPAD相比于传统的APD器件，可以连接更高精度的TDC，因此，该测距方法和测距系统相比于传统的测距方法和测距系统具有更高的精度。

Description

一种测距方法和测距系统
相关申请的交叉引用
本申请要求于2021年10月28日提交中国专利局的申请号为202111260507.7、申请名称为“一种测距方法和测距系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及测距领域，更具体的，涉及一种测距方法和测距系统。
背景技术
随着三维成像信息技术的迅速发展，特别是建筑测量、室内定位和导航、立体影像和辅助生活环境应用对飞行时间(Time-of-Flight，TOF)成像提出了迫切需求。飞行时间测距法(Time of flight，TOF)，其原理是通过向目标物连续发送光脉冲，然后用传感器接收从物体返回的光，通过探测光脉冲的飞行(往返)时间来得到目标物距离。
直接飞行时间探测(Direct Time of flight，DTOF)作为TOF的一种，DTOF技术通过计算光脉冲的发射和接收时间，直接获得目标距离，具有原理简单，信噪比好、灵敏度高、精确度高等优点，受到了越来越广泛的关注。
然而，在同一场景下，多台TOF设备同时工作时，会产生干扰 现象，导致测距精度不准确，现有技术中主要的解决方法有：频率调制技术，时钟同步技术等。相应的，在TOF设备的接收端，需要根据发射端的频率或者同步时钟进行相应的调制，以达到测距的目的。此外，现有技术中的使用单光子雪崩二极管(Single Photon Avalanche Diode，SPAD)的TOF设备，也会使用脉冲激光编码方式进行测距过程中的抗干扰。
然而，传统的使用脉冲激光编码方式虽然具有抗干扰性能，但是接收后直接进行统计，这样给后续处理电路带来极大的复杂度，同时，还需要更大量的存储开销，因此，需要提出一种可以节省存储空间的具有抗干扰性能的测距方法和测距系统。
发明内容
针对上述现有技术中的不足，本申请提供一种测距方法和测距系统，以解决现有技术中由于解决干扰问题而带来的存储开销大的缺陷。
本申请实施例采用的技术方案如下：
第一方面，本申请实施例提供一种测距方法，包括：
发射N个脉冲信号；
存储所述N个脉冲信号及其发射时间，形成序列A；
接收回波信号，所述回波信号触发SPAD雪崩；
存储所述SPAD被触发的时刻，形成序列B；
对所述序列A与所述序列B进行移动时间窗口卷积计算，并根 据所述计算结果得到测距结果。
在一种实施例中，所述N个脉冲信号由随机数生成。
在一种实施例中，所述N个脉冲信号的相邻脉冲的时间间隔随机。
在一种实施例中，所述N个脉冲的相邻脉冲的时间间隔与所述SPAD的死区时间成正比。
在一种实施例中，所述N个脉冲的个数与测距范围成正比。
第二方面，本申请实施例提供一种测距系统，包括：
发射模块，用于发射N个脉冲信号；
接收模块，用于接收回波信号，其中所述接收模块包括SPAD器件用于探测光信号，所述回波信号触发所述SPAD雪崩；
存储模块，用于存储所述N个脉冲信号及其发射时间形成序列A，以及所述SPAD被触发的时刻形成序列B；
计算模块，根据所述序列A与所述序列B进行移动时间窗口卷积计算，并根据所述计算结果得到测距结果。
在一种实施例中，所述N个脉冲信号由随机数生成。
在一种实施例中，所述N个脉冲信号的相邻脉冲的时间间隔随机。
在一种实施例中，所述N个脉冲的相邻脉冲的时间间隔与所述SPAD的死区时间成正比。
在一种实施例中，所述N个脉冲的个数与测距范围成正比。
本申请实施例提供一种测距方法和测距系统，相比传统的测距方法和测距系统，提高了设备的抗干扰性能。此外，由于SPAD相比于 传统的APD器件，可以连接更高精度的TDC，因此，本申请提出的测距系统和测距方法相比于传统的测距方法和测距系统具有更高的精度。另外，SPAD的状态可以直接用二进制数字0或1直接表示，相比于APD更加节省存储空间，也就是说，使用SPAD器件数字化之后，该测距系统可以减小数据量，支持更多并行处理的通道数，支持更大规模的阵列。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本申请的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为一种传统的探测系统示意图；
图2为采用传统的探测系统得到的测距结果的直方图；
图3为本申请实施例提供的一种测距方法的流程图；
图4为本申请实施例提供的一种测距系统的模块框图。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是 全部的实施例。通常在此处附图中描述和示出的本申请实施例的组件可以以各种不同的配置来布置和设计。
因此，以下对在附图中提供的本申请的实施例的详细描述并非旨在限制要求保护的本申请的范围，而是仅仅表示本申请的选定实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。
飞行时间测距法(Time of flight，TOF)，其原理是通过向目标物连续发送光脉冲，然后用传感器接收从物体返回的光，通过探测光脉冲的飞行(往返)时间来得到目标物距离。
而直接飞行时间探测(Direct Time of flight，DTOF)作为TOF的一种，DTOF技术通过计算光脉冲的发射和接收时间，直接获得目标距离，具有原理简单，信噪比好、灵敏度高、精确度高等优点，受到了越来越广泛的关注。
一般地，在一些DTOF测距应用中，可以使用包括单光子检测器(例如单光子雪崩二极管，Single Photon Avalanche Diode，SPAD，或单光子雪崩二极管阵列)的光电探测器阵列来执行光电探测的任务。一个或多个光电探测器可以限定阵列的探测器像素。SPAD阵列可以在可能需要高灵敏度和定时分辨率的成像应用中用作固态光电探测器。SPAD基于半导体结(例如，p-n结)，例如，当通过或响应 于具有期望脉冲宽度的选通信号而被偏置到其击穿区域之外时，该半导体结可以检测入射光子。高的反向偏置电压会产生足够大小的电场，从而使引入器件耗尽层的单个电荷载流子可以通过碰撞电离引起自持雪崩。
一般地，光在极其微弱时会离散成一个个的光子，称为单光子。单光子信号由于强度微弱且粒子性显著，常规技术难以对其检测，被认为是光电探测技术的极限，DTOF技术克服了光电探测技术的难点，实现单光子检测。
在DTOF技术中，是直接根据脉冲发射和接收的时间差来测算距离。激光发射的瞬间，电子时钟被激活。光束操纵单元将脉冲引导到所需方向。脉冲从探测目标反射回来，一部分被光电探测器所接收。在响应中，与前端电子器件连接的光电探测器产生电信号，从而使时钟生效。通过测量飞行时间Δt，计算出与反射物体之间的距离d，计算式为d＝cΔt/2，其中c指光在介质中的速度。
图1为传统的一种探测系统示意图，图2为采用传统探测系统得到的测距结果的直方统计图，即直方图。如图1，示意了探测系统获取目标距离的基本原理。具体地，处理单元120控制光源110发出发射光，其中光源可以为LED或者激光源。此处为了考虑人眼安全等，一般选择光源为具有近红外波长的激光源，激光源可以选择VSCEL阵列型激光源，此处并不限定。光源110中至少部分单元发射探测光，当然也包含了全部发出发射光和部分发出发射光的场景，此处不做限定。为了实现能量集中和系统工作的高效性，通常使用部分输出单元 输出发射光。接收模块130包含SPAD单光子雪崩二极管探测单元，这样可以实现对于微弱能量下的准确探测。
在实际的探测过程中，光源发射具有一定脉宽的脉冲激光例如几纳秒级别，通过数以万次的发射由统计结果获得最终的目标距离信息。脉冲激光经过探测目标140反射，然后返回至处于包含雪崩状态SPAD的阵列型接收模块，其中处于雪崩状态的探测单元可以接收返回的信号，返回的信号可以是发射脉冲光束的回波并形成光子信号。当接收模块的SPAD被施加高的偏置电压时，接收模块的SPAD单元处于雪崩状态，因此可以感测背景光或者返回信号光的光子，再利用处理模块的统计功能，对于触发事件进行大量的统计，通过统计结果构造出直方图，例如，如图2所示。对于直方图的触发概率高的时间段信息输出即可实现对于探测目标140的距离信息获取。
然而，对于直方图统计的测距方法，需要消耗大量的内存，因此本申请提出了一种测距方法和测距系统。
如图3所示，是本申请提供的一种测距方法的流程图。下面详细说明本申请提供的测距方法的具体步骤。
一般地，测距系统包括发射模块和接收模块，发射模块用于发射探测信号，接收模块用于接收回波信号，并根据该回波信号进行处理得到距离信息。
S1，发射N个脉冲信号。
首先，发射模块发射N个脉冲信号，该脉冲信号的脉冲间隔不 是固定值，可以是随机值，例如，N可以是1024，即一次探测发射1024个脉冲，脉冲平均间隔为10ns左右，间隔分为8ns和12ns。
S2，存储N个脉冲信号及其发射时间，形成序列A。
将上一步骤S1中发射出的N个脉冲信号存储在电路中的存储模块，形成序列A。
例如，将上一步骤中1024个脉冲存储，脉冲间隔为8ns的代表0，脉冲间隔是12ns的代表1，这样会产生一列长度为1024个数字的伪随机序列，并将其存储至存储模块中。
S3，接收回波信号，所述回波信号触发SPAD雪崩。
接收模块接收回波信号，回波信号可以引起接收模块中的SPAD器件雪崩，产生雪崩信号，该雪崩信号用于记录SPAD是否被触发。
S4，存储SPAD被触发的时刻形成序列B。
当接收模块接收到回波信号以后，SPAD被触发，存储模块则记录SPAD被触发的时刻，并记录和存储该时刻。
例如，将一个探测周期的时间设置为11600ns，覆盖了1333.33ns的飞行时间，对应200m范围的测距，以及1024个光脉冲所占的10240ns时间。
时间从0时刻开始时，时间精度设置为1ns，记录SPAD是否被触发，0表示SPAD被触发，1表示SPAD没有被触发，记录到一个探测周期11600ns时间结束。
S5，对序列A与序列B进行移动时间窗口卷积(Time correlated moving convolution，TCMC)，得到测距结果。
对于序列A和B进行移动窗口卷积，移动的窗口时间为0～1333ns，即代表0～200m量程。每次移动一个最小时间(Δt)得到一个卷积结果，即
f(Δt)＝A(t+Δt)*B(t)。
示例性地，卷积的操作如下流程：
第一步，设置Δt＝0ns时，序列A的全部(10240bit)和序列B的第一个至10240个bit一一相乘，再相加，得到C1即：
C_1＝sum[A(1:10240).*B(1:10240)]；
第二步，设置Δt＝1ns时，列A的全部(10240bit)和序列B的第二个至10240个bit一一相乘，再相加，得到C2即：
C_2＝sum[A(1:10240).*B(2:10240)]；
循环往复，可以得到整个代表卷积结果的C序列，即：
C＝[C_1,C_2,C_3,……C_n]；
C_n＝sum[A(1:10240).*B(n:10240+n)]
最后，在C序列中找到最大值Cm，则回波时间即为m ns。最终将时间转换为距离，就可以直接得到探测距离。
因此，本申请提供的测距方法可以应用在多台测量设备同时工作的场景下，提高了设备的抗干扰性能。此外，由于SPAD相比于传统 的APD器件，可以连接更高精度的TDC，因此，本申请提出的测距系统和测距方法相比于传统的测距设备具有更高的精度。另外，SPAD的状态可以直接用二进制数字0或1直接表示，相比于APD更加节省存储空间，也就是说，使用SPAD器件数字化之后，该测距系统可以减小数据量，支持更多并行处理的通道数，支持更大规模的阵列。
此外，本申请还提供一种测距系统，如图4所示，包括发射模块401、接收模块402、存储模块403，以及计算模块405。
发射模块401用于发射N个脉冲信号。该脉冲信号的脉冲间隔不是固定值，可以是随机值，例如，N可以是1024，即一次探测发射1024个脉冲，脉冲平均间隔为10ns左右，间隔分为8ns和12ns。
接收模块402包括SPAD器件，SPAD用于探测光信号。接收模块402接收回波信号，回波信号可以引起接收模块中的SPAD器件雪崩，产生雪崩信号，该信号用于记录SPAD是否被触发。
当接收模块402接收到回波信号以后，SPAD被触发，存储模块403则记录SPAD被触发的时刻，并记录和存储该时刻，形成序列B。
存储模块403，还用于存储发射出的N个脉冲信号的序列A。
计算模块405，用于根据序列A与序列B进行移动时间窗口卷积计算，并根据计算结果得到测距结果。
需要说明的是，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者设备不仅包括那些要素，而且还包括没有明确列出的其他要素，或 者是还包括为这种过程、方法、物品或者设备所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括所述要素的过程、方法、物品或者设备中还存在另外的相同要素。
以上所述仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。以上所述仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (10)

  1. 一种测距方法，包括：
    发射N个脉冲信号；
    存储所述N个脉冲信号及其发射时间，形成序列A；
    接收回波信号，所述回波信号触发SPAD雪崩；
    存储所述SPAD被触发的时刻，形成序列B；
    对所述序列A与所述序列B进行移动时间窗口卷积计算，并根据所述计算结果得到测距结果。
  2. 如权利要求1所述的测距方法，所述N个脉冲信号由随机数生成。
  3. 如权利要求1或2所述的测距方法，所述N个脉冲信号的相邻脉冲的时间间隔随机。
  4. 如权利要求3所述的测距方法，所述N个脉冲的相邻脉冲的时间间隔与所述SPAD的死区时间成正比，且大于1。
  5. 如权力要求4所述的测距方法，所述N个脉冲的个数与测距范围成正比。
  6. 一种测距系统，包括：
    发射模块，用于发射N个脉冲信号；
    接收模块，用于接收回波信号，其中所述接收模块包括SPAD器件用于探测光信号，所述回波信号触发所述SPAD雪崩；
    存储模块，用于存储所述N个脉冲信号及其发射时间形成序列A，以及所述SPAD被触发的时刻形成序列B；
    计算模块，根据所述序列A与所述序列B进行移动时间窗口卷积计算，并根据所述计算结果得到测距结果。
  7. 如权利要求6所述的测距系统，所述N个脉冲信号由随机数生成。
  8. 如权利要求6或7所述的测距系统，所述N个脉冲信号的相邻脉冲的时间间隔随机。
  9. 如权利要求8所述的测距系统，所述N个脉冲的相邻脉冲的时间间隔与所述SPAD的死区时间成正比。
  10. 如权利要求8所述的测距系统，所述N个脉冲的个数与测距范围成正比。
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