阅读说明：本技术 一种适用于探测复杂场景的距离选通门控制方法及装置 (Distance gate control method and device suitable for detecting complex scene ) 是由 江峦 陈路 尤蓉蓉 肖志伟 吕冰冰 于 2019-09-26 设计创作，主要内容包括：本发明涉及一种适用于探测复杂场景的距离选通门控制方法,包括：实时检测每一探测周期内的所有反射光信号；根据预设阈值判断当前探测周期检测到的每一反射光信号是否为有效信号,并获取第一个有效信号的波峰时刻t<Sub>1</Sub>和最后一个有效信号的波峰时刻t<Sub>2</Sub>；根据第一个有效信号的波峰时刻和预设的距离选通门打开的时间提前量t<Sub>3</Sub>,确定距离选通门的打开时间,其中,距离选通门的打开时间t<Sub>on</Sub>计算公式为：t<Sub>on(The invention relates to a distance gate control method suitable for detecting complex scenes, which comprises the following steps: detecting all reflected light signals in each detection period in real time; judging whether each reflected light signal detected in the current detection period is an effective signal according to a preset threshold value, and acquiring the peak time t of the first effective signal 1 And the peak time t of the last useful signal 2 (ii) a According to the peak time of the first effective signal and the preset time lead t of opening the distance gate 3 Determining the opening time of the distance gate, wherein the opening time t of the distance gate on The calculation formula is as follows: t is t on =t 1 –t 3 (ii) a According to the peak time of the last effective signal and the preset time delay t from the gate closing 4 Determining the closing time of the distance gate, wherein the closing time t of the distance gate off The calculation formula is as follows: t is t off =t 2 +t 4 . The embodiment of the invention also provides a range gate control device suitable for detecting the complex scene. The method is suitable for detecting the complex scene.)

1. A distance gate control method suitable for detecting complex scenes comprises the following steps:

detecting all reflected light signals in each detection period in real time;

judging whether each reflected light signal detected in the current detection period is an effective signal according to a preset threshold value, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂；

According to the peak time of the first effective signal and the preset time lead t of opening the distance gate₃Determining the opening time of the distance gate, wherein the opening time t of the distance gate_onThe calculation formula is as follows: t is t_on=t₁–t₃；

According to the peak time of the last effective signal and the preset time delay t from the gate closing₄Determining the closing time of the distance gate, wherein the closing time t of the distance gate_offThe calculation formula is as follows: t is t_off=t₂+t₄。

2. The method for controlling a range gate suitable for detecting a complex scene according to claim 1, wherein: judging whether each reflected light signal detected in the current detection period is an effective signal according to a preset threshold value, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂The method also comprises the following steps:

according to the peak time t of the first effective signal detected by the detection period to the current detection period₁And the peak time t of the last useful signal₂The marking and storing is performed to provide reference data for the next detection cycle from the open time of the gate and from the closed time of the gate.

3. The method for controlling a range gate suitable for detecting a complex scene according to claim 1, wherein: further comprising:

determining the pulse width according to the opening time and the closing time of the distance gate, wherein the calculation formula of the pulse width delta t is as follows: Δ t = t_off-t_on；

Controlling a stripe camera to obtain a target image according to the pulse width;

judging whether the signal-to-noise ratio of the target image meets a preset value or not, and if so, judging that the pulse width is properly set; if not, adjusting the time advance and/or the time delay of the gate according to the preset time adjustment interval to adjust the pulse width to be proper, and further obtaining the image quality meeting the requirement.

4. The method for controlling a range gate suitable for detecting a complex scene according to claim 1, wherein: further comprising: and detecting the water body turbidity of the detected water area, and selecting the laser with the corresponding wave band and the laser pulse corresponding to the laser with the selected wave band according to the water body turbidity.

5. An apparatus for controlling a range gate suitable for detecting a complex scene according to any one of claims 1 to 4, wherein: comprises a detection unit and a control unit;

the detection unit is used for sending all detected reflected light signals of each detection period to the control unit in real time;

the control sheetElement according to a preset threshold value T_SNRJudging whether each reflected light signal detected in the current detection period is an effective signal or not, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂；

According to the peak time of the first effective signal and the preset time lead t of opening the distance gate₃Determining the opening time of the distance gate, wherein the opening time t of the distance gate_onThe calculation formula is as follows: t is t_on=t₁–t₃；

According to the peak time of the last effective signal and the preset time delay t from the gate closing₄Determining the closing time of the distance gate, wherein the closing time t of the distance gate_offThe calculation formula is as follows: t is t_off=t₂+t₄。

6. The range gate control apparatus adapted to detect a complex scene according to claim 5, wherein: the detection unit comprises a water body turbidity detection unit, and the water body turbidity detection unit sends the detected water body turbidity of the detection water area to the control unit so that the control unit controls the laser wave band and the pulse according to the water body turbidity.

7. The range gate control apparatus adapted to detect a complex scene according to claim 5, wherein: the control unit comprises a time acquisition module, an opening time determination module and a closing time determination module;

the time acquisition module is used for acquiring the time according to a preset threshold value T_SNRJudging whether each reflected light signal detected in the current detection period is an effective signal or not, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂；

The opening time determining module is used for selecting the opening time lead t of the gate according to the peak time of the first effective signal and the preset distance₃Gate for determining distanceIs at an opening time t from the gate_onThe calculation formula is as follows: t is t_on=t₁–t₃；

The closing time determining module is used for determining the closing time of the gate according to the peak moment of the last effective signal and the preset time delay t from the closing of the gate₄Determining the closing time of the distance gate, wherein the closing time t of the distance gate_offThe calculation formula is as follows: t is t_off=t₂+t₄。

8. The range gate control apparatus adapted to detect a complex scene according to claim 5, wherein: the control unit further comprises a reference module, and the reference module acquires the peak moment t of the first effective signal detected in the current detection period₁And the peak time t of the last useful signal₂And detecting the peak time t of the first effective signal detected in the current detection period according to the detection period₁And the peak time t of the last useful signal₂The marking and storing is performed to provide reference data for the next detection cycle from the open time of the gate and from the closed time of the gate.

9. The range gate control apparatus adapted to detect a complex scene according to claim 5, wherein: the control unit further comprises a pulse width adjusting module, and the pulse width adjusting module determines the pulse width according to the opening time and the closing time of the distance gate; controlling a stripe camera to obtain a target image according to the pulse width; judging whether the signal-to-noise ratio of the target image meets a preset value or not, and if so, judging that the pulse width is properly set; if not, adjusting the time advance and/or the time delay from the gate to be closed according to the preset time adjustment interval so as to adjust the pulse width to be proper.

10. The range gate control apparatus adapted to detect a complex scene according to claim 5, wherein: the control unit further comprises a laser control module, and the laser control module selects laser with corresponding wave bands and pulses corresponding to the laser with the selected wave bands according to the turbidity of the water body in the detected water area.

Technical Field

The invention relates to the technical field of radar detection, in particular to a distance gate control method and device suitable for detecting complex scenes.

Background

The range gating streak tube laser radar has the advantages of being unique in the detection field, particularly the underwater detection field, high in range resolution, and the range gating mechanism can effectively reduce the influence of water body backscattering on a measurement result. In practice, however, complex scenes are often required to be detected, for example, multiple targets appear in the radar field of view simultaneously in the same detection period, a target or a platform carrying a laser radar moves, and the like, and the complex scenes cause that the opening time and the closing time of the range gate cannot be accurately determined, or even optical signals reflected by the targets cannot be received.

Based on the technical problems, the applicant searches solutions in the prior art, and finds an invention patent application with publication number CN110018495A, named as a streak tube imaging laser radar laser emission random error measurement and compensation system, and an invention patent application with publication number CN106814356A, named as a distance tracking subsystem based on a radar signal processing system, through a large amount of searches; wherein, a streak pipe formation of image lidar laser emission random error measurement and compensating system's technical scheme mainly includes: the system comprises a fringe tube laser radar laser emission random error measuring module, a fringe camera and an image processing end. The laser light is projected to a target, and the time difference information is transmitted to an image processing end by a streak tube laser radar laser emission random error measurement module; the stripe camera collects laser reflected by a target and outputs an image to the image processing end, and the image processing end performs time compensation by combining time difference and the image, so that measurement errors caused by laser delay jitter are eliminated. It can be seen that this prior patent application does not present a solution to the above technical problem. A technical scheme of a distance tracking subsystem based on a radar signal processing system mainly comprises the following steps: the device comprises a range gate gating module, a pulse compression module, a coherent accumulation MTD module, a constant false alarm detection module, a tracking gate module, a distance centering processing module, a distance measurement module and a Kalman filtering module/alpha-beta filtering module. According to the scheme, the delay of a range gating gate is controlled, a target is detected after a channel signal is subjected to matched filtering, MTD and constant false alarm detection, then unambiguous ranging is carried out through tracking gate and range centering processing, the range gating gate is generated through Kalman filtering or alpha-beta filtering, the center of the gate is aligned to the target signal detected by an echo, so that the gate is ensured to move to automatically track the target, and the whole radar signal processing system realizes a signal processing flow of intermediate frequency signal detection and range tracking on the obtained intermediate frequency signal. It is clear that this prior patent application also does not present a solution to the above technical problem.

Disclosure of Invention

In view of this, the embodiment of the present invention provides a method and an apparatus for controlling a range gate, which are suitable for detecting a complex scene.

In order to achieve the above technical object, an embodiment of the present invention provides a method for controlling a range gate, which is suitable for detecting a complex scene, and includes: detecting all reflected light signals in each detection period in real time; judging whether each reflected light signal detected in the current detection period is an effective signal according to a preset threshold value, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂(ii) a According to the peak time of the first effective signal and the preset time lead t of opening the distance gate₃Determining the opening time of the distance gate, wherein the opening time t of the distance gate_onThe calculation formula is as follows: t is t_on=t₁–t₃(ii) a According to the peak time of the last effective signal and the preset time delay t from the gate closing₄Determining the closing time of the distance gate, wherein the closing time t of the distance gate_offThe calculation formula is as follows: t is t_off=t₂+t₄。

To achieve the technical purpose, the inventionThe embodiment of the invention also provides a distance gate control device suitable for detecting complex scenes, which comprises: a detection unit and a control unit; the detection unit is used for sending all detected reflected light signals of each detection period to the control unit in real time; the control unit is used for controlling the power supply according to a preset threshold value T_SNRJudging whether each reflected light signal detected in the current detection period is an effective signal or not, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂(ii) a According to the peak time of the first effective signal and the preset time lead t of opening the distance gate₃Determining the opening time of the distance gate, wherein the opening time t of the distance gate_onThe calculation formula is as follows: t is t_on=t₁–t₃(ii) a According to the peak time of the last effective signal and the preset time delay t from the gate closing₄Determining the closing time of the distance gate, wherein the closing time t of the distance gate_offThe calculation formula is as follows: t is t_off=t₂+t₄

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages:

according to the method, all reflected light signals in each detection period are detected in real time, effective signals are filtered through the preset threshold, and by acquiring the peak time of the first effective signal and the peak time of the last effective signal, and correspondingly preset time lead for opening the range gate and preset time delay for closing the range gate, the opening time and the closing time of the range gate can be accurately determined in similar complex scenes that a plurality of targets simultaneously appear in the field of view of a radar in the same detection period, so that the method is very convenient and reliable.

The invention has simple and reliable design structure, convenient operation and accurate detection result, and can be widely applied to the technical field of radar detection.

Drawings

FIG. 1 is a schematic diagram of a detection image of one embodiment of a range gate control method suitable for detecting complex scenes according to the present invention;

fig. 2 is a schematic structural diagram of one embodiment of the range gate control device suitable for detecting complex scenes.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments and accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.

The embodiment of the invention provides a distance gate control method suitable for detecting a complex scene, which comprises the following steps as shown in fig. 1:

detecting all reflected light signals in each detection period in real time;

according to a preset threshold value T_SNRJudging whether each reflected light signal detected in the current detection period is an effective signal or not, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂In this embodiment, two reflected light signals are detected only in one detection period, and both the two reflected light signals are valid, which is described simply, but the actual detection condition is not limited thereto;

according to the peak time of the first effective signal and the preset time lead t of opening the distance gate₃Determining the opening time of the distance gate, wherein the opening time t of the distance gate_onThe calculation formula is as follows: t is t_on=t₁–t₃；

According to the peak time of the last effective signal and the preset time delay t from the gate closing₄Determining the closing time of the distance gate, wherein the closing time t of the distance gate_offThe calculation formula is as follows: t is t_off=t₂+t₄。

Through the scheme, all the reflected light signals in each detection period are detected in real time, effective signals are filtered through the preset threshold, and by acquiring the peak time of the first effective signal and the peak time of the last effective signal, and correspondingly preset time lead for opening the range gate and preset time delay for closing the range gate, the opening time and the closing time of the range gate can be accurately determined in similar complex scenes that a plurality of targets simultaneously appear in the field of view of a radar in the same detection period.

In one embodiment, according to a preset threshold T_SNRJudging whether each reflected light signal detected in the current detection period is an effective signal or not, and acquiring the peak time t of the first effective signal₁And the peak time t of the last useful signal₂The method also comprises the following steps:

according to the peak time t of the first effective signal detected by the detection period to the current detection period₁And the peak time t of the last useful signal₂Marking and storing to provide reference data of the opening time of the gate and the closing time of the gate for the next detection period;

according to the peak time t of the first effective signal detected by the detection period to the current detection period₁And the peak time t of the last useful signal₂Marking and storing, for example:

the peak time of the first effective signal acquired in the nth detection period is marked as: t is t_{1_n}(ii) a The peak time of the last effective signal acquired in the nth detection period is marked as: t is t_{2_n}(ii) a Wherein n is the number of detection cycles and is a positive integer.

Due to the fact that the target or the platform with the laser radar can move when the complex environment is detected, if the range gating time is not changed all the time, the stripe camera cannot receive the optical signal reflected by the target, through the scheme, a compensation method or a reference basis is provided, and even when the target or the platform with the laser radar moves back and forth, the stripe camera of the laser radar can still effectively capture the optical signal reflected by the target.

In an embodiment, the above distance gate control method suitable for detecting a complex scene further includes:

determining the pulse width according to the opening time and the closing time of the distance gate, wherein the calculation formula of the pulse width delta t is as follows: Δ t = t_off-t_on；

Controlling a stripe camera to obtain a target image according to the pulse width;

judging whether the signal-to-noise ratio of the target image meets a preset value or not, and if so, judging that the pulse width is properly set; if not, adjusting the time advance for opening the distance gate and/or the time delay for closing the distance gate according to a preset time adjustment interval to adjust to a proper pulse width so as to obtain the image quality meeting the requirement;

examples illustrate in detail: assuming that the pulse width is 2 mus and the preset signal-to-noise ratio is 8, if the judgment condition is that the signal-to-noise ratio of the obtained image is greater than the preset signal-to-noise ratio, the preset time adjustment interval is 0.01 mus;

controlling a stripe camera to acquire a target image according to the pulse width of 2 mu s, wherein the signal-to-noise ratio of the target image is 8.5, the signal-to-noise ratio is obviously consistent with the preset value of the signal-to-noise ratio of 8, and the image quality meets the requirement, namely the pulse width is properly set;

controlling a stripe camera to acquire a target image according to the pulse width of 2 mu s, wherein the signal-to-noise ratio of the target image is 7, and the signal-to-noise ratio of the target image is obviously not in accordance with a preset value 8 of the signal-to-noise ratio, which indicates that the image quality is not satisfactory, i.e. the pulse width setting is not appropriate, at this time, there are at least three pulse width adjustment modes: firstly, independently adjusting the time advance of the opening of the distance gate; secondly, independently adjusting the time delay amount of closing the distance gate; thirdly, adjusting the time advance for opening the distance gate and the time delay for closing the distance gate at the same time;

since the three pulse width adjustment methods are basically the same, for avoiding redundancy, only the first method is taken as an example for explanation here: and successively reducing the time lead of opening the distance gate by 0.01 mu s each time, acquiring the adjusted pulse width, controlling the stripe camera to acquire a target image according to the adjusted pulse width, judging whether the signal-to-noise ratio of the target image meets a preset value, stopping adjustment if the signal-to-noise ratio of the target image meets the preset value, and repeating the steps if the signal-to-noise ratio of the target image does not meet the preset value.

By the scheme, the pulse width is automatically adjusted according to the signal-to-noise ratio of the acquired target image so as to acquire the target image meeting the requirement, and later observation or use is facilitated.

In an embodiment, the above distance gate control method suitable for detecting a complex scene further includes: detecting the water body turbidity of a detection water area, and selecting laser with a corresponding wave band and laser pulse corresponding to the laser with the selected wave band according to the water body turbidity;