阅读说明：本技术 一种条纹管激光雷达距离选通门控制方法及装置 (Stripe tube laser radar distance gate control method and device ) 是由 江峦 陈路 尤蓉蓉 易先林 肖志伟 吕冰冰 于 2019-12-05 设计创作，主要内容包括：本发明涉及一种条纹管激光雷达距离选通门控制方法,包括：检测激光发射时刻；检测接收到反射光信号时刻；根据激光发射时刻和接收到反射光信号时刻确定往返时间；根据激光发射时刻、往返时间和预设的距离选通门打开的时间提前量,确定距离选通门的打开时间；根据激光发射时刻、往返时间和预设的距离选通门关闭的时间延迟量,确定距离选通门的关闭时间。本发明还涉及一种条纹管激光雷达距离选通门控制装置。本发明能够在不确定目标距离的情况下,自动确定距离选通门打开时间和关闭。(The invention relates to a stripe tube laser radar distance gate control method, which comprises the following steps: detecting the laser emission time; detecting the moment when the reflected light signal is received; determining round trip time according to the laser emission time and the reflected light signal receiving time; determining the opening time of the distance gate according to the laser emission time, the round trip time and the preset time lead for opening the distance gate; and determining the closing time of the distance gate according to the laser emission time, the round-trip time and the preset time delay amount of the distance gate for closing. The invention also relates to a stripe tube laser radar distance gate control device. The invention can automatically determine the opening time and closing of the distance gate under the condition of uncertain target distance.)

1. A streak tube laser radar distance gate control method comprises the following steps:

detecting the laser emission time t₁；

Detecting the time t at which the reflected light signal is received₂；

Determining round trip time according to the laser emission time and the reflected light signal receiving time, wherein the round trip time delta T is calculated by the formula: Δ T = T₂-t₁；

According to the laser emission time, the round trip time and the preset time lead t for 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+ΔT-t₃；

According to the laser emission time, the round trip time and the preset distanceTime delay t for gating off₄Determining 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=t₁+ΔT+t₄。

2. The method for controlling the range gate of the streak tube laser radar according to claim 1, wherein: the method further comprises the following steps:

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 from the gate to be closed according to the preset time adjustment interval so as to adjust the pulse width to be proper.

3. The method for controlling the range gate of the streak tube laser radar according to claim 1, wherein: the method further comprises the following steps: 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.

4. The method for controlling a range gate of a laser radar of a streak tube according to claim 3, wherein: the turbidity of the water body in each range, the laser in each wave band and the pulse corresponding to the laser in each wave band are prestored in a form of a table.

5. A device based on the stripe tube lidar range gate control method of any of claims 1 to 4, wherein: comprises a detection unit and a control unit;

the detection unit is used for sending the detected laser emission time and the detected reflected light signal receiving time to the control unit;

the control unit determines the round trip time according to the laser emission time and the time of receiving the reflected light signal, determines the opening time of the distance gate according to the laser emission time, the round trip time and the preset time advance for opening the distance gate, and determines the closing time of the distance gate according to the laser emission time, the round trip time and the preset time delay for closing the distance gate.

6. The apparatus of claim 5, wherein the detection unit comprises a laser, a first photodetector, and a second photodetector;

the laser emits laser according to the control instruction of the control unit;

the first photoelectric detector sends the detected laser emission time to the control unit;

and the second photoelectric detector sends the detected received reflected light signal to the control unit at any time.

7. The device of claim 6, wherein the detection unit further comprises a water turbidity detection unit, and the water turbidity detection unit sends the detected water turbidity of the detected water area to the control unit, so that the control unit controls the laser band and pulse of the laser according to the water turbidity.

8. The apparatus of claim 5, wherein the control unit comprises a round trip time determination module, an on time determination module, and an off time determination module;

the round-trip time determining module determines the round-trip time according to the laser emitting time and the reflected light signal receiving time;

the opening time determining module determines the opening time of the distance gate according to the laser emission time, the round trip time and the preset time lead for opening the distance gate;

and the closing time determining module determines the closing time of the distance gate according to the laser emission time, the round-trip time and the preset time delay amount for closing the distance gate.

9. The device of claim 5, the control unit further comprising a pulse width adjustment module that determines a pulse width based on an opening time and a closing time from the gate; acquiring 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 apparatus of claim 7, wherein the control unit further comprises a laser control module, and the laser control module selects the laser with the corresponding wavelength band and the laser pulse corresponding to the laser with the selected wavelength band 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 method and a device for controlling a distance gate of a streak tube laser radar.

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. However, in practical application, it is found that, under the condition that the target distance is uncertain, the stripe tube laser radar cannot determine the time of opening the distance gate, which may result in that the stripe tube laser radar cannot receive the optical signal reflected by the target, and as the time of opening the distance gate cannot be determined, the time of closing the distance gate cannot be determined indirectly, which is obvious, and thus the technical advantage of excellent distance gate control mode cannot be realized.

Based on the technical problems, the applicant searches solutions in the prior art, and finds that the invention patent application with publication number CN110018495A, named as a streak tube imaging laser radar laser emission random error measurement and compensation system, and the invention patent application with publication number CN102623883A, named as a distance gating synchronous control device based on pulse laser scattering light synchronization are found 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. The technical scheme of the range gating synchronous control device based on pulse laser scattering light synchronization mainly comprises the following steps: the distance gating synchronous control device based on pulse laser scattering light synchronization comprises a photoelectric conversion circuit, a synchronous control signal driver, a central control and data exchanger, a composite synchronous control signal driver and two programmable delayers, wherein the photoelectric conversion circuit outputs a source trigger signal after detecting laser pulses by using the scattering light of the laser pulses, and the source trigger signal respectively triggers the synchronous control signal driver and the composite synchronous control signal driver. The synchronous control signal driver outputs a pulse signal with delay information and width information, and the pulse signal is adjusted by the programmable delayer and then is output to the image intensifier; the composite synchronous control signal driver outputs a composite synchronous signal with delay information, and the composite synchronous signal is adjusted by a programmable delayer and then is output to the camera. And sending control commands and modifying configuration data to the central control and data exchanger through the main control computer. The scheme synchronously controls the camera and the image intensifier, so that the pulse laser imaging system has accurate range gating imaging capability. 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, embodiments of the present invention provide a method and an apparatus for controlling a range gate of a streak tube laser radar, which can automatically determine an opening time and a closing time of the range gate under the condition that a target distance is not determined.

In order to achieve the above technical object, an embodiment of the present invention provides a method for controlling a range gate of a streak tube laser radar, including: detecting the laser emission time t₁(ii) a Detecting the time t at which the reflected light signal is received₂(ii) a Determining round trip time according to the laser emission time and the reflected light signal receiving time, wherein the round trip time delta T is calculated by the formula: Δ T = T₂-t₁(ii) a According to the laser emission time, the round trip time and the preset time lead t for 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+ΔT-t₃(ii) a According to the laser emission time, the round trip time 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=t₁+ΔT+t₄。

In order to achieve the above technical object, an embodiment of the present invention further provides a stripe tube lidar range gate control device, including: a detection unit and a control unit; the detection unit is used for sending the detected laser emission time and the detected reflected light signal receiving time to the control unit; the control unit determines the round trip time according to the laser emission time and the time of receiving the reflected light signal, determines the opening time of the distance gate according to the laser emission time, the round trip time and the preset time advance for opening the distance gate, and determines the closing time of the distance gate according to the laser emission time, the round trip time and the preset time delay for closing the distance gate.

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

according to the invention, the opening time and the closing time of the distance gate can be determined under the condition of not determining the target distance by detecting the laser emission time, the time of receiving the reflected light signal, the time advance of the opening of the preset distance gate and the time delay of the closing of the preset distance gate, so that the method is very convenient.

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 probe image of one embodiment of a fringe tube lidar range gate control method of the present invention;

fig. 2 is a schematic structural diagram of one embodiment of the streak tube lidar range gate control device of the present invention.

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 method for controlling a distance gate of a streak tube laser radar, which comprises the following steps as shown in figure 1:

detecting the laser emission time t₁；

Detecting the time t at which the reflected light signal is received₂；

Determining round trip time according to the laser emission time and the reflected light signal receiving time, wherein the round trip time delta T is calculated by the formula: Δ T = T₂-t₁；

According to the laser emission time, the round trip time and the preset time lead t for 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+ΔT-t₃；

According to the laser emission time, the round trip time 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=t₁+ΔT+t₄。

By the scheme, under the condition that the target distance is uncertain, the opening time and the closing time of the distance gate can be determined by detecting the laser emission time, the time when the reflected light signal is received, the preset time advance for opening the distance gate and the preset time delay for closing the distance gate, so that the method is very convenient, and the control method is particularly suitable for quickly and accurately detecting simple scenes, wherein the detected simple scenes comprise scenes that only a single target appears in a radar visual field and the target and an airborne detector are relatively static;

at the same time, by mixing t_onAnd t_offIs set as above, instead of using t_on= t₂- t₃Or t_off= t₂+ΔT+t₄And other calculation modes, the influence of the dynamic variable on the calculation result is effectively avoided, so that t is enabled to be_onAnd t_offThe calculation results of (2) are relatively stable.

In an embodiment, the method for controlling the distance gate of the streak tube lidar 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 method for controlling the distance gate of the streak tube lidar 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;