CN115685227A - a detection method - Google Patents
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Abstract
Translated fromChinese
Description
Translated fromChinese技术领域technical field
本申请涉及探测技术领域，特别涉及一种探测方法。The present application relates to the technical field of detection, in particular to a detection method.
背景技术Background technique
飞行时间测距法(Time of flight，TOF)，其原理是通过给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。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 .
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，同样采用ITOF的方案也能够获得高精度和高灵敏度的距离检测方案。Direct Time of Flight (DTOF) 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 advantages have received more and more attention, and the same ITOF solution can also obtain a high-precision and high-sensitivity distance detection solution.
直接飞行时间探测包括直接测量发射辐射与从物体或其他目标反射后检测辐射之间的时间长度。由此，可以确定到目标的距离。Direct time-of-flight detection involves directly measuring the length of time between emission of radiation and detection of radiation after it has reflected from an object or other target. From this, the distance to the target can be determined.
在一些应用中，可以使用包括单光子检测器(例如单光子)在内的光电探测器阵列来执行反射辐射的感测In some applications, sensing of reflected radiation can be performed using photodetector arrays including single photon detectors such as single photon
雪崩二极管(SPAD)阵列。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)，当例如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。可以通过淬火电路主动(例如，通过降低偏置电压)或被动地(例如，通过使用串联电阻两端的压降)对雪崩进行淬火，以使设备“复位”以进一步检测光子。起始电荷载流子可以通过单个入射光子撞击高电场区域而光电产生。正是这一功能使人们产生了“单光子雪崩二极管”的名称。这种单光子检测操作模式通常称为“盖革模式”。Avalanche diode (SPAD) array. One or more photodetectors may define detector pixels of the array. SPAD arrays can be used as solid-state photodetectors in imaging applications where high sensitivity and timing resolution may be required. SPADs are based on semiconductor junctions (eg, p-n junctions) that can detect incident photons when biased outside of their breakdown region, eg, by 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. The avalanche can be quenched actively (eg, by reducing the bias voltage) or passively (eg, by using a voltage drop across a series resistor) by a quenching circuit to "reset" the device for further photon detection. Initial charge carriers can be photogenerated by a single incident photon striking a region of high electric field. It is this feature that has led to the name "Single Photon Avalanche Diode". This single-photon detection mode of operation is often referred to as the "Geiger mode".
为了计数入射在SPAD阵列上的光子，某些ToF像素方法可能使用数字计数器或模拟计数器来指示光子的检测和到达时间，也称为时间戳记。数字计数器可能更易于实现和扩展，但是就面积而言(例如，相对于阵列的物理尺寸而言)可能更昂贵。模拟计数器可能更紧凑，但是可能会受到光子计数深度(位深)，噪声和/或均匀性问题的限制。To count photons incident on the SPAD array, some ToF pixel approaches may use digital or analog counters to indicate the photon detection and arrival times, also known as time stamps. Digital counters may be easier to implement and scale, but may be more expensive in terms of area (eg, relative to the physical size of the array). Analog counters may be more compact, but may be limited by photon counting depth (bit depth), noise and/or uniformity issues.
为了给入射光子加上时间戳，一些基于SPAD阵列的ToF像素方法使用了时间数字转换器(TDC)。TDC可以在飞行时间成像应用中使用，以提高单个时钟周期的定时分辨率。这种数字方法的一些优势可能包括TDC的大小倾向于随着技术节点而扩展，并且所存储的值可以对泄漏更健壮。To time-stamp incoming photons, some ToF pixel approaches based on SPAD arrays use time-to-digital converters (TDCs). TDCs can be used in time-of-flight imaging applications to improve the timing resolution of individual clock cycles. Some advantages of this digital approach may include that the size of the TDC tends to scale with technology nodes, and that the stored values can be more robust to leakage.
但是，TDC电路可能只能在单个事件中处理一个事件测量周期，这样一排SPAD可能需要多个TDC。TDC可能也比较耗电，这使得更大的阵列更难以实现。TDC还可能生成相对大量的数据，例如，每个光子一个16位时间戳。连接到TDC的单个SPAD可能每秒产生数百万个这样的时间戳。因此，相对于可用的输入/输出带宽或功能，大于100,000像素的成像阵列会产生不可行的大数据速率。但是完全不使用TDC测量精度又达不到。所以亟需一种探测装置及探测方法来解决上述问题。However, the TDC circuit may only be able to handle one event measurement cycle in a single event, so multiple TDCs may be required for a bank of SPADs. TDCs can also be more power hungry, making larger arrays more difficult to implement. TDCs may also generate relatively large amounts of data, for example, a 16-bit timestamp per photon. A single SPAD connected to a TDC could generate millions of these timestamps per second. Thus, imaging arrays greater than 100,000 pixels would yield unfeasibly large data rates relative to the available input/output bandwidth or capabilities. However, the measurement accuracy cannot be achieved without using TDC at all. Therefore, there is an urgent need for a detection device and a detection method to solve the above problems.
发明内容Contents of the invention
本申请的目的在于，针对上述现有技术中的不足，提供一种探测及方法，以解决现有的探测方法中TDC数据量过大的技术问题。The purpose of the present application is to provide a detection method and a method for solving the technical problem of excessive TDC data volume in the existing detection method.
为实现上述目的，本申请实施例采用的技术方案如下：In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:
第一方面，本申请实施例提供了一种探测方法，其特征在于，包括：In the first aspect, the embodiment of the present application provides a detection method, which is characterized in that it includes:
在第N帧获得第一飞行时间，以第N帧的第一飞行时间为基础，在第N+1帧以第二时间精度单元绘制第二直方图；根据所述第二直方图判断是否可以获得第二飞行时间，其中，N为大于等于1的正整数。Obtain the first time-of-flight in the Nth frame, draw the second histogram in the second time precision unit in the N+1th frame based on the first time-of-flight in the Nth frame; judge whether it is possible according to the second histogram The second flight time is obtained, wherein, N is a positive integer greater than or equal to 1.
可选地，在第N帧以第一时间精度单元绘制第一直方图，根据所述第一直方图获得第一飞行时间；Optionally, draw a first histogram with a first time precision unit at the Nth frame, and obtain a first time-of-flight according to the first histogram;
在第N帧以第二时间精度单元绘制第二直方图，根据所述第二直方图获得第二飞行时间，其中，N为大于等于1的正整数。Drawing a second histogram in a second time precision unit at the Nth frame, and obtaining a second time-of-flight according to the second histogram, where N is a positive integer greater than or equal to 1.
可选地，在第N+1帧以所述第二时间精度单元绘制第二直方图，其中N为大于等于1的正整数。Optionally, the second histogram is drawn with the second time precision unit at the N+1th frame, where N is a positive integer greater than or equal to 1.
可选地，根据所述第二时间精度单元绘制第二直方图获得第二飞行时间，并输出所述第二飞行时间。Optionally, draw a second histogram according to the second time precision unit to obtain a second time-of-flight, and output the second time-of-flight.
可选地，根据所述第二时间精度单元绘制第二直方图不能获得第二飞行时间，在所述第N+1帧以第一时间精度单元绘制第一直方图。Optionally, the second time-of-flight cannot be obtained by drawing the second histogram according to the second time precision unit, and draw the first histogram in the first time precision unit at the N+1th frame.
可选地，其特征在于，所述第一时间精度单元大于所述第二时间精度单元。Optionally, it is characterized in that the first time precision unit is greater than the second time precision unit.
可选地，基于所述第一或第二直方图利用最大峰值法获得所述第一或第二飞行时间。Optionally, the first or second time-of-flight is obtained by using a maximum peak method based on the first or second histogram.
可选地，以所述第一飞行时间为基础，在一个所述第一时间精度单元范围内以所述第二时间精度单元绘制第二直方图。Optionally, based on the first time-of-flight, draw a second histogram with the second time precision unit within a range of the first time precision unit.
可选地，以所述第一飞行时间为中心扩展一个所述第一时间精度单元，在扩展的范围内以所述第二时间精度单元绘制第二直方图。Optionally, one unit of the first time precision is expanded with the first time-of-flight as the center, and a second histogram is drawn with the unit of the second time precision within the extended range.
可选地，还包括以第三时间精度单元绘制第三直方图。所述第二时间精度单元大于所述第三时间精度单元。Optionally, drawing a third histogram with a third time precision unit is also included. The second time precision unit is greater than the third time precision unit.
本申请的有益效果是：The beneficial effect of this application is:
本申请实施例提供的一种探测方法，该探测方法包括：以第二时间精度单元绘制第二直方图；根据所述第二直方图判断是否可以获得第二飞行时间。通过如此设计，实现可以从第二直方图或者第三直方图直接开始探测，当无法获得飞行时间的时候才从第一飞行时间开始探测。这样就可以进一步减小TDC的数据存储量。A detection method provided by an embodiment of the present application includes: drawing a second histogram with a second time precision unit; judging whether the second flight time can be obtained according to the second histogram. With such a design, the detection can be directly started from the second histogram or the third histogram, and the detection can be started from the first time-of-flight when the time-of-flight cannot be obtained. In this way, the data storage capacity of the TDC can be further reduced.
附图说明Description of drawings
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。In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.
图1为本申请实施例提供的一种探测装置的功能模块示意图；FIG. 1 is a schematic diagram of functional modules of a detection device provided in an embodiment of the present application;
图2为本申请实施例提供的一种直方图示意图；FIG. 2 is a schematic diagram of a histogram provided in an embodiment of the present application;
图3为本申请实施例提供的一种探测方法示意图；FIG. 3 is a schematic diagram of a detection method provided by an embodiment of the present application;
图4为本申请实施例提供的一种第一直方图与第二直方图关系的示意图；FIG. 4 is a schematic diagram of a relationship between a first histogram and a second histogram provided in an embodiment of the present application;
图5为本申请实施例提供的另一种探测方法示意图；FIG. 5 is a schematic diagram of another detection method provided by the embodiment of the present application;
图6为本申请实施例提供的另一种第一直方图与第二直方图关系的示意图；Fig. 6 is another schematic diagram of the relationship between the first histogram and the second histogram provided by the embodiment of the present application;
图7为本申请实施例提供的另一种探测方法示意图；FIG. 7 is a schematic diagram of another detection method provided by the embodiment of the present application;
图8为本申请实施例提供的又一种探测方法示意图。FIG. 8 is a schematic diagram of another detection method provided by the embodiment of the present application.
具体实施方式Detailed ways
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。In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of them. The components of the embodiments of the application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.
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。Accordingly, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.
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。It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.
图1为本申请实施例提供的一种探测装置的功能模块示意图。如图1所示，该探测装置包括：脉冲光源101、待测物102、探测器阵列103以及处理模块104。FIG. 1 is a schematic diagram of functional modules of a detection device provided by an embodiment of the present application. As shown in FIG. 1 , the detection device includes: a pulsed
其中，脉冲光源101，用于发射探测脉冲到待测物102，待测物102反射部分的脉冲光源至探测器阵列103。探测阵列103可以是SPAD阵列，探测阵列103接收到反射回来的光子，当反射回来的光子撞击高电场区域而光电产生引起SAPD的雪崩。TDC模块根据反射光子的到达时间生成时间码，处理模块104可以根据所述时间码生成直方图，最终根据直方图获得反射光子到达的精确时间。其中TDC模块可以处于探测器阵列中也可以是单独的模块与探测器阵列电连接，本申请不做具体限制。Wherein, the pulsed
获得反射光子的到达时间后就可以根据光子的到达时间检测出待测物的距离。距离D可由下式计算出：After obtaining the arrival time of the reflected photons, the distance of the object to be measured can be detected according to the arrival time of the photons. The distance D can be calculated by the following formula:
D＝c·t/2 (1)D＝c·t/2 (1)
其中，c为光速。where c is the speed of light.
图2为本申请实施例提供的一种直方图示意图。如图2所示，FIG. 2 is a schematic diagram of a histogram provided in an embodiment of the present application. as shown in
其中ΔT指的是探测窗口的宽度，T1、T2分别指直方图绘制的起始与终止时刻，[T1、T2]是该直方图的时间区间，T＝T2-T1指的是总的时间宽度，时间单元ΔT的纵坐标即是相应探测窗口内所收到的光子计数值，基于该直方图可以利用最大峰值法等方法确定脉冲波形的位置，并得到相应的飞行时间t。Among them, ΔT refers to the width of the detection window, T1 and T2 respectively refer to the start and end moments of the histogram drawing, [T1, T2] is the time interval of the histogram, and T=T2-T1 refers to the total time width , the ordinate of the time unit ΔT is the photon count value received in the corresponding detection window. Based on the histogram, the position of the pulse waveform can be determined by methods such as the maximum peak method, and the corresponding flight time t can be obtained.
现有的一些解决方案中为了减小TDC的数据量，首先以第一时间精度单元绘制第一直方图，利用第一直方图用如图2所示的方法计算得出第一飞行时间。根据所述第一飞行时间，以第二时间精度单元绘制第二直方图；利用所述第二直方图计算第二飞行时间。其中第一直方图的时间区间大于第二直方图的时间区间，或者，第一直方图的时间分辨率小于第二直方图的时间分辨率。这样就可以减小一部分的TDC数据量，但是在每次的探测中仍然分别需要进行第一飞行时间与第二飞行时间探测，TDC的数据量还是相当大。In some existing solutions, in order to reduce the amount of TDC data, first draw the first histogram with the first time precision unit, and use the first histogram to calculate the first flight time with the method shown in Figure 2 . Drawing a second histogram with a second time precision unit according to the first time-of-flight; calculating the second time-of-flight by using the second histogram. The time interval of the first histogram is greater than the time interval of the second histogram, or the time resolution of the first histogram is smaller than the time resolution of the second histogram. In this way, a part of the TDC data amount can be reduced, but the first time-of-flight and the second time-of-flight detection are still required in each detection, and the amount of TDC data is still quite large.
图3为本申请实施例提供的一种探测方法示意图。如图3所示的探测方法，S301开始探测的第一帧首先以第一时间精度单元绘制第一直方图，S302根据第一直方图计算第一飞行时间，S303以第二精度绘制第二直方图，S304根据第二直方图计算第二飞行时间并输出第二飞行时间，其中第一直方图的时间区间大于第二直方图的时间区间，或者，第一直方图的时间精度小于第二直方图的时间精度。这样就可以得到满足精度需求的待测目标位置。在探测过程中第一飞行时间获得过程中的ΔT较大，分辨能力较差，不能满足探测需求，但是因为分辨相对比较小需要存储的TDC数据就比较少，可以通过第一飞行时间获得待测物体的粗略位置，例如在图2所示的示意图中，根据直方图确定t的准确位置有一定困难，而且ΔT的分比率比较小就是ΔT的时间区间比较大，满足不了探测需求，只能获得待测物体的粗略位置。所以在获得第二飞行时间的过程中，在第一飞行时间的基础上第二飞行时间的ΔT2的时间区间ΔT的时间区间小，分辨率提升如图4所示的示意图。FIG. 3 is a schematic diagram of a detection method provided by an embodiment of the present application. In the detection method shown in Figure 3, S301 first draws the first histogram with the first time precision unit at the first frame of detection, S302 calculates the first flight time according to the first histogram, and S303 draws the first time-of-flight with the second precision Two histograms, S304 calculates the second time-of-flight according to the second histogram and outputs the second time-of-flight, wherein the time interval of the first histogram is greater than the time interval of the second histogram, or the time accuracy of the first histogram Less than the time precision of the second histogram. In this way, the position of the target to be measured that meets the accuracy requirement can be obtained. In the detection process, the ΔT in the process of obtaining the first flight time is relatively large, and the resolution is poor, which cannot meet the detection requirements. However, because the resolution is relatively small, the TDC data that needs to be stored is relatively small, and the test can be obtained through the first flight time. The rough position of the object, for example, in the schematic diagram shown in Figure 2, it is difficult to determine the exact position of t according to the histogram, and the ratio of ΔT is relatively small, which means that the time interval of ΔT is relatively large, which cannot meet the detection requirements and can only be obtained The rough position of the object to be measured. Therefore, in the process of obtaining the second flight time, the time interval of ΔT2 of the second flight time on the basis of the first flight time is small, and the resolution is improved as shown in FIG. 4 .
图4为本申请实施例提供的一种第一直方图与第二直方图关系的示意图。如图4所示根据第一直方图可以获得第一飞行时间在t1-t2之间，关于确定第一飞行时间的方法现有技术中有很多种方案这里就不再赘述。例如第一直方图的ΔT可以是500ps，就是第一直方图的时间分辨率就是500ps。第二直方图在第一直方图的基础上ΔT2可以是62.5ps，这里的时间分辨率只是为了示意说明，并不做具体限制。如图4所示在第一直方图的第一飞行时间基础上t1-t2范围内将时间精度提高到62.5ps，根据第二直方图得到第二飞行时间t3。如果第二飞行时间t3还达不到探测精度需求就可以以此类推在第二飞行时间的基础上得到第三飞行时间，进一步的提高探测精度，直到获得的飞行时间能够满足探测精度的需求。FIG. 4 is a schematic diagram of a relationship between a first histogram and a second histogram provided in an embodiment of the present application. As shown in FIG. 4 , the first flight time can be obtained according to the first histogram between t1 -t2 . As for the method for determining the first flight time, there are many solutions in the prior art and will not be repeated here. For example, ΔT of the first histogram may be 500 ps, that is, the time resolution of the first histogram is 500 ps. Based on the first histogram, the ΔT2 of the second histogram may be 62.5 ps, and the time resolution here is only for illustration and not specifically limited. As shown in FIG. 4 , based on the first flight time of the first histogram, the time accuracy is increased to 62.5 ps within the range of t1-t2, and the second flight time t3 is obtained according to the second histogram. If the second flight time t3 does not meet the detection accuracy requirements, the third flight time can be obtained by analogy on the basis of the second flight time, and the detection accuracy is further improved until the obtained flight time can meet the detection accuracy requirements.
上述的探测过程虽然为了减小TDC的存储数据量，分为了第一直方图和第二直方图，但是每次都还是要进行第一直方图与第二直方图的探测，这样对TDC产生数据量的减小很有限。图3提出了一种新的探测方法，能够进一步减小TDC产生的数据量。如图3所示在开始进行探测的过程中首先按照上述的过程分别进行第一飞行时间与第二飞行时间的探测。在第N帧(例如第一帧)的时候首先进行按照上述S301～S304的过程分别进行第一飞行时间与第二飞行时间的探测，并获得满足探测需求的第二飞行时间。S305在第N+1帧(例如第二帧)直接以第二时间精度单元绘制第二直方图，S306根据第N+1帧的直方图计算第N+1帧的第二飞行时间，如果能正常计算出第二飞行时间则S307输出第二飞行时间的结果，如果不能获得第二飞行时间说明待测物已经移动出了第二直方图的探测范围。所以要重新进行第一直方图的探测过程，重新进行第一飞行时间与第二飞行时间的探测，所以探测过程返回到S301。在图3所示的探测方法中如果在第N+1帧可以直接通过第二直方图得到第二飞行时间，就可以进一步的减小TDC的数据存储量和计算量，进一步提高探测效率。Although the above detection process is divided into the first histogram and the second histogram in order to reduce the amount of stored data in TDC, the detection of the first histogram and the second histogram is still required each time, so that the TDC The reduction in the amount of generated data is very limited. Figure 3 proposes a new detection method that can further reduce the amount of data generated by TDC. As shown in FIG. 3 , in the process of starting the detection, the detection of the first time-of-flight and the second time-of-flight are performed respectively according to the above-mentioned process. At the Nth frame (for example, the first frame), the detection of the first time-of-flight and the second time-of-flight is performed respectively according to the above-mentioned processes of S301-S304, and the second time-of-flight meeting the detection requirements is obtained. S305 directly draws the second histogram with the second time precision unit in the N+1th frame (such as the second frame), and S306 calculates the second flight time of the N+1th frame according to the histogram of the N+1th frame, if it can If the second time-of-flight is normally calculated, S307 outputs the result of the second time-of-flight. If the second time-of-flight cannot be obtained, it means that the object under test has moved out of the detection range of the second histogram. Therefore, the detection process of the first histogram must be performed again, and the detection of the first time-of-flight and the second time-of-flight must be performed again, so the detection process returns to S301. In the detection method shown in FIG. 3 , if the second time-of-flight can be obtained directly through the second histogram at frame N+1, the amount of data storage and calculation of the TDC can be further reduced, and the detection efficiency can be further improved.
图3所示的第N+1帧中直接以第二时间精度绘制第二直方图获得第二飞行时间的探测过程在有些实施列中也可以通过如图5所示的方法来实现。图3所示的探测过程中在第N+1帧中直接进行以第二时间精度单元绘制第二直方图的时候受制于第一时间精度单元起始点，因为第二直方图的绘制是以第一飞行时间为基础的。在图5所示的探测方法中第N帧获得第二飞行时间的过程与图3所示的方法相同，也就是说S501～S504与S301～S304所示的探测过程相同这里就不再赘述。然后在获得第N帧的第二飞行时间后，S505以第二飞行时间为中心扩展一个时间范围，所述扩展的时间范围是第一时间精度的时间单元。然后在这个扩展的时间范围内S506以第二时间精度单元绘制第二直方图，根据第N+1帧的直方图计算第N+1帧的第二飞行时间，S507如果能正常计算出第二飞行时间则S508输出第二飞行时间的结果，如果不能获得第二飞行时间说明待测物已经移动出了第二直方图的探测范围。所以要重新进行第一直方图的探测过程，重新进行第一飞行时间与第二飞行时间的探测，也就是第N+1帧要重新从S501开始进行探测。图5所示的探测过程相对于图3所示的探测过程的优势在于不受第一时间精度单元的起始点的限制。其第一直方图与第二直方图的关系示意如图6所示。The detection process of directly drawing the second histogram with the second time precision in the N+1th frame shown in FIG. 3 to obtain the second time-of-flight may also be implemented by the method shown in FIG. 5 in some embodiments. In the detection process shown in Figure 3, when the second histogram is directly drawn in the second time precision unit in the N+1 frame, it is subject to the starting point of the first time precision unit, because the drawing of the second histogram is based on the first time precision unit A flight time based. In the detection method shown in FIG. 5 , the process of obtaining the second time-of-flight in the Nth frame is the same as the method shown in FIG. 3 , that is to say, S501-S504 is the same as the detection process shown in S301-S304 and will not be repeated here. Then, after obtaining the second time-of-flight of the Nth frame, S505 expands a time range around the second time-of-flight, and the extended time range is a time unit of the first time precision. Then, within this extended time range, S506 draws a second histogram with the second time precision unit, and calculates the second flight time of the N+1th frame according to the histogram of the N+1th frame. If S507 can normally calculate the second Time-of-flight: S508 outputs the result of the second time-of-flight. If the second time-of-flight cannot be obtained, it means that the object under test has moved out of the detection range of the second histogram. Therefore, the detection process of the first histogram needs to be performed again, and the detection of the first time-of-flight and the second time-of-flight must be performed again, that is, the detection of the N+1th frame should be performed again from S501. Compared with the detection process shown in FIG. 3 , the detection process shown in FIG. 5 has the advantage that it is not limited by the starting point of the first time precision unit. The relationship between the first histogram and the second histogram is shown in FIG. 6 .
图6为本申请实施例提供的另一种第一直方图与第二直方图关系的示意图；如图6所示，根据第一直方图可以获得第一飞行时间，以所述第一飞行时间为基础，前后各扩充1/2个ΔT，如图6所示从第一直方图得到的第一飞行时间为t1，那么就以t1为中心，前后各扩充1/2个ΔT，然后在t1-ΔT/2～t1+ΔT/2的范围以第二时间精度单元绘制第二直方图。例如在第N帧的探测过程中获得的第二飞行时间为1000ps，第一精度的时间单元为500ps，那么就以1000ps为中心，左右各扩展500/2ps，然后在第N+1帧中在1250ps～750ps时间范围内以第二时间精度单元绘制第二直方图。Fig. 6 is another schematic diagram of the relationship between the first histogram and the second histogram provided by the embodiment of the present application; as shown in Fig. 6, the first flight time can be obtained according to the first histogram, and the first Based on the flight time, 1/2 ΔT is expanded before and after, as shown in Figure 6, the first flight time obtained from the first histogram is t1, then centered on t1, 1/2 ΔT is expanded before and after, Then draw a second histogram in a second time precision unit within the range of t1-ΔT/2˜t1+ΔT/2. For example, the second flight time obtained in the detection process of the Nth frame is 1000ps, and the time unit of the first precision is 500ps, then take 1000ps as the center, and expand 500/2ps on the left and right, and then in the N+1th frame in The second histogram is drawn in the second time precision unit within the time range of 1250ps to 750ps.
图7为本申请实施例提供的另一种探测方法示意图。如图7所示S701～S704的探测过程与上述的S301～S304所述的探测过程类似这里就不再赘述。S705以S704为基础以第三精度时间单元绘制第三直方图，其中上述实施列都是以第二飞行时间能够满足探测需求来示意说明的，但是在实际的探测过程总第二飞行时间可能满足不了探测需求，这就需要在第二直方图的基础上以第三时间精度单元绘制第三直方图，并根据第三直方图获得第三飞行之间。其中第二直方图的时间区间大于第三直方图的时间区间，或者，第二直方图的时间分辨率小于第三直方图的时间分辨率。S705以第三精度时间单元绘制第三直方图，S706根据第三直方图获得第三飞行时间并输出第N帧的第三飞行时间。S707中以第三飞行时间为中心扩展一个时间范围，所述扩展的时间范围是一个第二时间精度的时间单元。当然在S707中也可以不采取扩展时间范围的方式，而是在第二飞行时间的基础上进行一个第二时间精度单元的探测。如图3所示的方法。然后在这个扩展的时间范围内S708以第三时间精度单元绘制第三直方图，S709根据第N+1帧的直方图计算第N+1帧的第三飞行时间，S709如果能正常计算出第二飞行时间则S710输出第二飞行时间的结果，如果不能获得第三飞行时间说明待测物已经移动出了第三直方图的探测范围。所以要重新进行第一直方图的探测过程，重新进行第一飞行时间与第二飞行时间的探测，也就是第N+1帧要重新从S701开始进行探测。FIG. 7 is a schematic diagram of another detection method provided by the embodiment of the present application. As shown in FIG. 7 , the detection process of S701-S704 is similar to the detection process described in S301-S304 above, and will not be repeated here. S705 is based on S704 and draws the third histogram with the third precision time unit. The above-mentioned implementations are all schematically illustrated by the fact that the second flight time can meet the detection requirements, but in the actual detection process, the total second flight time may satisfy To meet the detection requirements, it is necessary to draw a third histogram with a third time precision unit on the basis of the second histogram, and obtain a third flight time according to the third histogram. The time interval of the second histogram is greater than the time interval of the third histogram, or the time resolution of the second histogram is smaller than the time resolution of the third histogram. S705 draws a third histogram in a third-precision time unit, and S706 obtains a third time-of-flight according to the third histogram and outputs the third time-of-flight of the Nth frame. In S707, a time range is extended centering on the third flight time, and the extended time range is a time unit of the second time precision. Of course, in S707, the method of extending the time range may not be adopted, but the detection of a second time precision unit is performed on the basis of the second flight time. The method shown in Figure 3. Then, within this extended time range, S708 draws the third histogram with the third time precision unit, and S709 calculates the third flight time of the N+1th frame according to the histogram of the N+1th frame. If S709 can normally calculate the third time of flight If the second time-of-flight is obtained, S710 outputs the result of the second time-of-flight. If the third time-of-flight cannot be obtained, it means that the object under test has moved out of the detection range of the third histogram. Therefore, the detection process of the first histogram needs to be performed again, and the detection of the first time-of-flight and the second time-of-flight must be performed again, that is, the detection of the N+1th frame should be performed again from S701.
图8为本申请实施例提供的又一种探测方法示意图。如图8所示S801～S803的探测过程与上述的S701～S703所述的探测过程类似在这里就不再赘述。然后在S804中判断是否可以根据第二直方图获得第二飞行时间如果可S804可以获得第二飞行时间则进行S805～S809的探测过程，其探测过程与S705～S709的过程类似这里就不再赘述。S809如果能正常计算出第二飞行时间则S810输出第三飞行时间的结果，如果不能获得第三飞行时间说明待测物已经移动出了第三直方图的探测范围。所以要重新进行第二直方图的探测过程，返回S803进行探测，然后在S804判断是否可以根据第二直方图获得第二飞行时间如果可S804可以获得第二飞行时间则进行S805～S809的探测过程。如果不能获得第二飞行时间则则S804需要返回到S801进行第一飞行时间的探测。FIG. 8 is a schematic diagram of another detection method provided by the embodiment of the present application. As shown in FIG. 8 , the detection process of S801-S803 is similar to the detection process described in S701-S703 above, and will not be repeated here. Then in S804, it is judged whether the second flight time can be obtained according to the second histogram. If the second flight time can be obtained in S804, then the detection process of S805-S809 is performed. The detection process is similar to the process of S705-S709 and will not be repeated here. . S809 If the second flight time can be calculated normally, S810 outputs the result of the third flight time. If the third flight time cannot be obtained, it means that the object under test has moved out of the detection range of the third histogram. Therefore, the detection process of the second histogram needs to be performed again, return to S803 for detection, and then judge in S804 whether the second flight time can be obtained according to the second histogram, and if the second flight time can be obtained in S804, then perform the detection process of S805-S809 . If the second flight time cannot be obtained, S804 needs to return to S801 to detect the first flight time.
图7和图8所示的实施列示意了分三个时间精度来探测飞行时间的过程，但是并不局限于只有三个飞行时间，只是为了示意说明。The embodiments shown in FIG. 7 and FIG. 8 illustrate the process of detecting the time-of-flight with three time accuracies, but it is not limited to only three time-of-flight, which is just for illustration.
需要说明的是，在本文中，诸如“第一”和“第二”等之类的关系术语仅仅用来将一个实体或者操作与另一个实体或操作区分开来，而不一定要求或者暗示这些实体或操作之间存在任何这种实际的关系或者顺序。而且，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。It should be noted that in this article, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these No such actual relationship or order exists between entities or operations. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.
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。The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application. It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.
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