A multi-target remote laser ranging system and method in high-speed search state

Abstract

The application discloses a kind of high-speed search state under the method of multi-target remote laser ranging, it includes: flyback refrigeration infrared thermal imager (1), laser range finder (2), servo control combination (3), information processing combination (4), computer display control (5).Flyback refrigeration infrared thermal imager (1) sends image to information processing combination (4) after imaging, laser range finder (2) sends data to information processing combination (4) after measuring target distance, servo control combination (3) sends current azimuth and pitch angle to information processing combination (4), information processing combination (4) is connected computer display control (5) by Ethernet, and real-time image and ranging result and target servo position are sent to it and are displayed.The application has the characteristics such as high target three-dimensional information data precision, ranging range is far, and multiple targets can be ranged in a circle.

Description

Technical Field

[0001] This invention relates to the field of laser ranging, and in particular to a multi-target long-range laser ranging system and method under high-speed search conditions. Background Technology

[0002] Military units, airports, and border areas frequently need to monitor and record suspicious aerial targets to identify those threatening local personnel and facilities. Measuring the location and distance of unidentified flying objects at airports or foreign reconnaissance equipment in border areas is particularly crucial. Existing laser ranging systems have several limitations: long-range ranging can only be effective when the optical axis is continuously aimed at the target, thus limiting it to tracking and ranging only one target at a time; while multi-target ranging lidar systems can only achieve short-range ranging of a few meters to tens of meters, unable to range long-range targets. Summary of the Invention

[0003] The purpose of this invention is to provide a control and protection design method for a high-load optical measurement system, which solves the problem of equipment or personnel damage caused by stalling or overrunning due to misoperation or equipment failure in the high-load optical measurement system.

[0004] A multi-target long-range laser ranging system in high-speed search mode, the system comprising:

[0005] A scan-cooled infrared thermal imager (1), a laser rangefinder (2), a servo control unit (3), an information processing unit (4), and a computer display and control unit (5);

[0006] The backscan cooled infrared thermal imager (1) and the laser rangefinder (2) are mounted on the servo control assembly (3) with a preset angle difference α. The image and communication output interfaces of the backscan cooled infrared thermal imager (1), the laser rangefinder (2) and the servo control assembly (3) are connected to the information processing assembly (4). The information processing assembly (4) is connected to the computer display and control (5).

[0007] In one embodiment, the preset angle difference is α.

[0008] A method for multi-target long-range laser ranging in a high-speed search state, the method being applied to the system described above, the method comprising:

[0009] After the system is powered on and the backscan infrared thermal imager (1) is cooled down, the servo system (3) takes the backscan thermal imager (1) and the laser rangefinder (2) and starts to rotate at a high speed of 360° / s. The information processing unit (4) receives an infrared image at a preset interval, then performs target detection on the image. After the target is detected, the delayed laser firing process is started according to the target position to complete the laser ranging.

[0010] In one embodiment, after completing laser ranging, the method further includes: displaying the three-dimensional data of the target on the display and control computer (5) and starting the next control cycle.

[0011] In one embodiment, the preset interval time is 10ms.

[0012] In one embodiment, the information processing unit (4) receives an infrared image at preset intervals, then performs target detection on the image, and after detecting the target, initiates a delayed laser ranging process based on the target location to complete the laser ranging process, including:

[0013] The information processing unit 4 controls the laser ranging process under the control of an external synchronization clock with a period of 10ms. When the first synchronization clock arrives, the back scan cooled infrared thermal imager acquires an image, and the servo control unit acquires the current turntable angle. At 2ms, the information processing unit receives the turntable angle acquired at 0ms, and at 9ms, the information processing unit begins to receive the infrared image acquired at 0ms.

[0014] In one embodiment, after the 2ms time-of-flight information processing group receives the turntable angle acquired at 0ms time, and the 9ms time-of-flight information processing group starts receiving the infrared image acquired at 0ms time, it further includes:

[0015] The information processing unit completes target detection and extraction of the infrared image at 20ms. If a target exists in the image, the angle that the laser pitch mirror needs to swing and the delay time of laser emission are calculated based on the target's relative position in the image.

[0016] In one embodiment, the delay time of the laser emission is calculated using formula (1):

[0017] When the resolution of the infrared image is 512×640 and the field of view is 3.6°×4.5°, the pixel deviation of the target from the image center in the azimuth direction is represented by X, and the pixel deviation in the elevation direction is represented by Y, where X and Y are signed numbers and the first quadrant is positive, then the formula for calculating the laser emission delay time is:

[0018]

[0019] in

[0020] α is the angle between the laser optical axis and the infrared optical axis.

[0021] β is the azimuth field of view angle of a single infrared image.

[0022] W represents the number of azimuth pixels in a single infrared image.

[0023] v is the rotational speed of the turntable;

[0024] The required swing angle of the laser pitch mirror is calculated using formula (2).

[0025]

[0026] in

[0027] H represents the number of elevation pixels in a single infrared image.

[0028] γ is the pitch field of view angle of a single infrared image.

[0029] In one embodiment, after calculating the required swing angle of the laser pitch mirror and the laser emission delay time, the process includes:

[0030] After the calculation is completed, the laser power-on command is sent first, followed by the elevation mirror angle and emission delay time sent to the laser in sequence. Since the laser emission delay time is between 30ms and 40ms, the laser elevation mirror needs to swing into position before 30ms. After the laser ranging is completed, the information processing unit sends the image and target 3D information to the computer display control for display. Starting from 40ms, the next working cycle begins.

[0031] In one embodiment, after completing laser ranging, the method further includes: displaying the three-dimensional data of the target on the display and control computer (5) and starting the next control cycle, including:

[0032] The system completes the measurement of the azimuth, pitch, and distance of a target within 40ms and uploads the data to a computer for display. It can perform three-dimensional ranging of at least 25 remote targets per second.

[0033] This invention discloses a method for multi-target long-range laser ranging in a high-speed search state. It utilizes infrared and laser technology to acquire three-dimensional data of multiple targets under high-speed rotation, featuring high accuracy of target three-dimensional information data, long ranging range, and the ability to range multiple targets within one rotation. The method involves mounting a laser rangefinder and a back-scanning infrared thermal imager on a servo turntable rotating at 360° / s. The laser optical axis is installed with a 12.6° difference from the infrared optical axis. After the infrared thermal imager detects a target, it calculates the angle φ that the turntable needs to rotate to align with the target based on the target's position in the image. It then calculates the time t required for the turntable to rotate φ. Through strict timing delay, the laser rangefinder is immediately controlled to perform ranging when the laser optical axis reaches the target. After reporting the three-dimensional information, the next control cycle begins. This method can perform high-precision ranging of targets from 500m to 25km, and can acquire three-dimensional information of more than 20 targets per second, displaying the data on a display and control computer. Attached Figure Description

[0034] Figure 1This is a schematic diagram of the connection of a multi-target long-range laser ranging system under high-speed search conditions according to the present invention;

[0035] Figure 2 This is a schematic diagram of the laser ranging process control for the information processing assembly 4.

[0036] Figure 3 This is a schematic diagram of an infrared image.

[0037] 1. Recoil-fed cooled infrared thermal imager 2. Laser rangefinder 3. Servo control unit 4. Information processing unit 5. Computer display and control unit Detailed Implementation

[0038] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims.

[0039] While the invention can be extended in many forms of modification and substitution, and the specification also provides some specific embodiments and detailed descriptions, it should be understood that the inventors' intention is not to limit the invention to the specific embodiments described. On the contrary, the inventors' intention is to protect all improvements, equivalent substitutions and modifications made within the spirit or scope defined by this claim.

[0040] A multi-target long-range laser ranging system in high-speed search mode, the system comprising:

[0041] A scan-cooled infrared thermal imager (1), a laser rangefinder (2), a servo control unit (3), an information processing unit (4), and a computer display and control unit (5);

[0042] The backscan cooled infrared thermal imager (1) and the laser rangefinder (2) are mounted on the servo control assembly (3) with a preset angle difference of 12.6°. The image and communication output interfaces of the backscan cooled infrared thermal imager (1), the laser rangefinder (2) and the servo control assembly (3) are connected to the information processing assembly (4). The information processing assembly (4) is connected to the computer display and control (5).

[0043] In one embodiment, the preset angle difference is 12.6°.

[0044] A method for multi-target long-range laser ranging in a high-speed search state, the method being applied to the system described above, the method comprising:

[0045] After the system is powered on and the backscan infrared thermal imager (1) is cooled down, the servo system (3) takes the backscan thermal imager (1) and the laser rangefinder (2) and starts to rotate at a high speed of 360° / s. The information processing unit (4) receives an infrared image at a preset interval, then performs target detection on the image. After the target is detected, the delayed laser firing process is started according to the target position to complete the laser ranging.

[0046] In one embodiment, after completing laser ranging, the method further includes: displaying the three-dimensional data of the target on the display and control computer (5) and starting the next control cycle.

[0047] In one embodiment, the preset interval time is 10ms.

[0048] In one embodiment, the information processing unit (4) receives an infrared image at preset intervals, then performs target detection on the image, and after detecting the target, initiates a delayed laser ranging process based on the target location to complete the laser ranging process, including:

[0049] The information processing unit 4 controls the laser ranging process under the control of an external synchronization clock with a period of 10ms. When the first synchronization clock arrives, the back scan cooled infrared thermal imager acquires an image, and the servo control unit acquires the current turntable angle. At 2ms, the information processing unit receives the turntable angle acquired at 0ms, and at 9ms, the information processing unit begins to receive the infrared image acquired at 0ms.

[0050] In one embodiment, after the 2ms time-of-flight information processing group receives the turntable angle acquired at 0ms time, and the 9ms time-of-flight information processing group starts receiving the infrared image acquired at 0ms time, it further includes:

[0051] The information processing unit completes target detection and extraction of the infrared image at 20ms. If a target exists in the image, the angle that the laser pitch mirror needs to swing and the delay time of laser emission are calculated based on the target's relative position in the image.

[0052] In one embodiment, the delay time of the laser emission is calculated using formula (1):

[0053] When the resolution of the infrared image is 512×640 and the field of view is 3.6°×4.5°, the pixel deviation of the target from the image center in the azimuth direction is represented by X, and the pixel deviation in the elevation direction is represented by Y, where X and Y are signed numbers and the first quadrant is positive, then the formula for calculating the laser emission delay time is:

[0054]

[0055] in

[0056] α is the angle between the laser optical axis and the infrared optical axis.

[0057] β is the azimuth field of view angle of a single infrared image.

[0058] W represents the number of azimuth pixels in a single infrared image.

[0059] v is the rotational speed of the turntable;

[0060] The required swing angle of the laser pitch mirror is calculated using formula (2).

[0061]

[0062] in

[0063] H represents the number of elevation pixels in a single infrared image.

[0064] γ is the pitch field of view angle of a single infrared image.

[0065] In one embodiment, after calculating the required swing angle of the laser pitch mirror and the laser emission delay time, the process includes:

[0066] After the calculation is completed, the laser power-on command is sent first, followed by the elevation mirror angle and emission delay time sent to the laser in sequence. Since the laser emission delay time is between 30ms and 40ms, the laser elevation mirror needs to swing into position before 30ms. After the laser ranging is completed, the information processing unit sends the image and target 3D information to the computer display control for display. Starting from 40ms, the next working cycle begins.

[0067] In one embodiment, after completing laser ranging, the method further includes: displaying the three-dimensional data of the target on the display and control computer (5) and starting the next control cycle, including:

[0068] The system completes the measurement of the azimuth, pitch, and distance of a target within 40ms and uploads the data to a computer for display. It can perform three-dimensional ranging of at least 25 remote targets per second.

[0069] This invention discloses a method for multi-target long-range laser ranging in a high-speed search state. It utilizes infrared and laser technology to acquire three-dimensional data of multiple targets while rotating at high speed. This method features high accuracy of target three-dimensional information data, long ranging range, and the ability to range multiple targets within one rotation. Specifically, since the laser rangefinder's emission angle is 0.05°, the laser emission delay time must be accurate to within 70µs, which places extremely stringent requirements on the timing of information processing. This strict timing ensures that the system completes the measurement of the azimuth, elevation, and distance of a target within 40ms and uploads the data to a computer for display, achieving three-dimensional ranging of up to 25 long-range targets per second. This provides a guarantee for subsequent warning or interception.

[0070] In one embodiment, the present invention proposes a method for multi-target long-range laser ranging in a high-speed search state. The system includes: a back-scan cooled infrared thermal imager 1, a laser rangefinder 2, a servo control unit 3, an information processing unit 4, and a computer display and control unit 5.

[0071] like Figure 1 As shown, in the system, the image and communication output interfaces of the back-scan cooled infrared thermal imager 1, the laser rangefinder 2, and the servo control assembly 3 are connected to the information processing assembly 4, and the information processing assembly 4 is connected to the computer display and control 5.

[0072] After the system is powered on and the retrace infrared thermal imager is cooled down, the servo system, along with the retrace thermal imager and laser rangefinder, begins to rotate at high speed. The information processing unit receives an infrared image every 10ms, then performs target detection on the image. After the target is detected, the delayed laser firing process is initiated based on the target's position. After completing the laser ranging, the target's three-dimensional data is displayed on the display and control computer, and the next control cycle begins.

[0073] Information processing unit 4 controls the laser ranging process, such as Figure 2 As shown, the entire process is completed under the control of an external synchronization clock with a period of 10ms. When the first synchronization clock arrives, the retrace-cooled infrared thermal imager acquires an image, and the servo control unit acquires the current turntable angle. At 2ms, the information processing unit receives the turntable angle acquired at 0ms, and at 9ms, the information processing unit begins to receive the infrared image acquired at 0ms.

[0074] The information processing unit completes target detection and extraction from the infrared image at 20ms interval. If a target exists in the image, the angle at which the laser pitch mirror needs to swing and the laser emission delay time are calculated based on the target's relative position in the image. The laser emission delay time is calculated as follows:

[0075] like Figure 3As shown, the infrared image has a resolution of 512×640 and a field of view of 3.6°×4.5°. The pixel deviation of the target from the image center in the azimuth direction is represented by X, and the pixel deviation in the elevation direction is represented by Y. X and Y are signed numbers, with the first quadrant being positive. The formula for calculating the laser emission delay time is:

[0076]

[0077] in

[0078] α is the angle between the laser optical axis and the infrared optical axis.

[0079] β is the azimuth field of view angle of a single infrared image.

[0080] W represents the number of azimuth pixels in a single infrared image.

[0081] v is the rotational speed of the turntable;

[0082] The formula for calculating the required swing angle of the laser pitch mirror is:

[0083]

[0084] in

[0085] H represents the number of elevation pixels in a single infrared image.

[0086] γ is the pitch field of view angle of a single infrared image.

[0087] After calculation, the laser power-on command is sent first, followed by the elevation mirror angle and emission delay time. Since the laser emission delay time is between 30ms and 40ms, the laser elevation mirror must be in position before 30ms. After laser ranging is completed, the information processing unit sends the image and target 3D information to the computer display for viewing. The next work cycle begins at 40ms.

[0088] Because the laser rangefinder's emission angle is 0.05°, the laser emission delay time must be accurate to within 70µs, which places extremely stringent timing requirements on the information processing assembly. This strict timing ensures that the system can complete the measurement of a target's azimuth, elevation, and distance within 40ms and upload the data to a computer for display, achieving three-dimensional ranging of up to 25 remote targets per second. This provides a guarantee for subsequent warning or interception.

[0089] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the methods described in any of the above embodiments. Those skilled in the art will understand that implementing all or part of the processes in the methods of the above embodiments can be accomplished by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above.

[0090] A computer device includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the method described in any of the above embodiments. Specifically, the computer device may be a server, and the computer device includes a processor, a memory, a network interface, and a database connected via a system bus.

[0091] This invention discloses a method for multi-target long-range laser ranging in a high-speed search state. It utilizes infrared and laser technology to acquire three-dimensional data of multiple targets under high-speed rotation, featuring high accuracy of target three-dimensional information data, long ranging range, and the ability to range multiple targets within one rotation. The method involves mounting a laser rangefinder and a back-scanning infrared thermal imager on a servo turntable rotating at 360° / s. The laser optical axis is installed with a 12.6° difference from the infrared optical axis. After the infrared thermal imager detects a target, it calculates the angle φ that the turntable needs to rotate to align with the target based on the target's position in the image. It then calculates the time t required for the turntable to rotate φ. Through strict timing delay, the laser rangefinder is immediately controlled to perform ranging when the laser optical axis reaches the target. After reporting the three-dimensional information, the next control cycle begins. This method can perform high-precision ranging of targets from 500m to 25km, and can acquire three-dimensional information of more than 20 targets per second, displaying the data on a display and control computer.

Claims

1. A multi-target long-range laser ranging method under high-speed search conditions, the method being applied to a system including a backflip cooled infrared thermal imager (1), a laser rangefinder (2), a servo control assembly (3), an information processing assembly (4), and a computer display and control unit (5), characterized in that, The method includes: After the system is powered on and the retrace-cooled infrared thermal imager (1) is cooled down, the servo control combination (3) takes the retrace-cooled infrared thermal imager (1) and the laser rangefinder (2) and starts to rotate at a high speed of 360° / s. The information processing combination (4) receives an infrared image at a preset interval, then performs target detection on the image. After the target is detected, the delayed laser firing process is started according to the target position to complete the laser ranging. After completing laser ranging, the process also includes: displaying the three-dimensional data of the target on the computer display and control (5) and starting the next control cycle; Furthermore, the information processing unit (4) receives an infrared image at preset intervals, then performs target detection on the image, and after detecting the target, initiates a delayed laser ranging process based on the target position to complete the laser ranging process, including: The information processing unit (4) controls the laser ranging process under the control of an external synchronization clock with a period of 10ms. When the first synchronization clock arrives, the backscan cooled infrared thermal imager acquires an image, and the servo control unit acquires the current turntable angle. At 2ms, the information processing unit receives the turntable angle acquired at 0ms, and at 9ms, the information processing unit begins to receive the infrared image acquired at 0ms. After the information processing unit receives the turntable angle acquired at 0ms at 2ms and begins to receive the infrared image acquired at 0ms at 9ms, the process further includes: The information processing unit completes target detection and extraction of the infrared image at 20ms. If there is a target in the image, the angle that the laser pitch mirror needs to swing and the delay time of laser emission are calculated based on the relative position of the target in the image. And the delay time of the laser emission is calculated using formula (1): When the resolution of the infrared image is 512×640 and the field of view is 3.6˚×4.5˚, the pixel deviation of the target from the image center in the azimuth direction is represented by X, and the pixel deviation in the elevation direction is represented by Y, where X and Y are signed numbers and the first quadrant is positive, then the formula for calculating the laser emission delay time is: ...Official (1); in The angle between the laser optical axis and the infrared optical axis. This represents the azimuth field of view angle of a single infrared image. This represents the number of azimuth pixels in a single infrared image. This refers to the rotational speed of the turntable; The required swing angle of the laser pitch mirror is calculated using formula (2). ...Official (2); in This represents the number of elevation pixels in a single infrared image. This represents the pitch field of view angle of a single infrared image.

2. The method according to claim 1, characterized in that, After calculating the required swing angle of the laser pitch mirror and the laser emission delay time, the following steps are included: After the calculation is completed, the laser power-on command is sent first, followed by the elevation mirror angle and emission delay time sent to the laser in sequence. Since the laser emission delay time is between 30ms and 40ms, the laser elevation mirror needs to swing into position before 30ms. After the laser ranging is completed, the information processing unit sends the image and target 3D information to the computer display control for display. Starting from 40ms, the next working cycle begins.

3. The method according to claim 2, characterized in that, After completing the laser ranging, the process further includes: displaying the target's three-dimensional data on the computer display (5) and starting the next control cycle, including: The system completes the measurement of the azimuth, pitch, and distance of a target within 40ms and uploads the data to a computer for display. It can perform three-dimensional ranging of at least 25 remote targets per second.

4. The method according to claim 1, characterized in that, The preset interval time is 10ms.

5. A multi-target long-range laser ranging system for performing the method as described in claim 1 under high-speed search conditions, characterized in that, The system includes: Backscan cooled infrared thermal imager (1), laser rangefinder (2), servo control unit (3), information processing unit (4), computer display and control (5); The back-scan cooled infrared thermal imager (1) and the laser rangefinder (2) are positioned at a preset angle difference. The angle difference is installed on the servo control assembly (3). The image and communication output interfaces of the retrace-cooled infrared thermal imager (1), laser rangefinder (2) and servo control assembly (3) are connected to the information processing assembly (4). The information processing assembly (4) is connected to the computer display and control (5).

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