A method of calibrating the zero of a FOD detector based on radar imaging in an airport

Abstract

The application provides a method for calibrating zero position of FOD detector based on radar imaging in an airport, comprising the following steps: step 1, installing the detector according to the type of airport road and selecting the reference point accordingly; step 2, setting the scanning parameters, controlling the detection radar to carry out field survey scanning, obtaining the one-dimensional range image of the airport road and uploading the one-dimensional range image to the upper computer through the network; step 3, marking the position of the reference point according to the one-dimensional range image of the airport road by the upper computer; and step 4, completing the zero position calibration of the detector by running the actual zero position deviation value through the detector.

Description

Technical Field

[0001] This invention relates to the field of airport security monitoring technology, and more specifically to a method for calibrating the zero position of a FOD detector based on radar imaging in airports. Background Technology

[0002] Edge-lamp foreign object detectors (FOD detectors) are fully automated, all-day, all-weather detection devices used to assist or replace manual inspections of foreign objects appearing on airport runways. The detectors are symmetrically installed in front of the edge lights on both sides of the runway. Using radar and video sensors, they promptly detect, locate, and report randomly appearing foreign objects on the runway, greatly improving the efficiency of foreign object detection and effectively ensuring the safe takeoff and landing of aircraft.

[0003] Because the detectors are installed at a low height, typically between 350mm and 420mm, the detection radius of a single detector is approximately 70m. Taking a 3800m long runway as an example, approximately 120 detectors would be needed to achieve full coverage detection. Each detector needs to scan back and forth within a 0-180° range, therefore, zero-point calibration is required for each detector during installation to ensure consistency in their scanning range. A schematic diagram of detector deployment on an airport runway is shown below. Figure 1 As shown, the detector continuously scans the runway surface using internal radar sensors, converting the distance and angle information of detected foreign objects (FOOs) into airport-specific PH coordinates or GPS coordinates, thereby achieving precise target location. The radar acquires FEO angle information by reading the current turntable angle at the time of FEO detection. Therefore, accurate zero-point calibration of the detector not only ensures the consistency of the detector's detection range but also enables more precise FEO location after information conversion. Each detector needs to be zero-point set before leaving the factory. However, after installation on the runway surface, due to installation angle errors, the actual zero point after installation will deviate from the runway's horizontal direction. This zero-point error will affect the consistency of the detection range and the accuracy of target location.

[0004] Additionally, the detectors installed at the runway connecting taxiways are also responsible for detecting the area around the connecting taxiways. Since the connecting taxiways are generally irregularly shaped, a zero-point calibration method specifically for the detectors installed there is required. The detectors are installed at the following locations on the connecting taxiways: Figure 2As shown, the zero-point calibration of existing edge-lamp type foreign object detectors (FOD detectors) for airport runways is mainly achieved manually through visual inspection. This method involves visually determining the detector's zero-point orientation as it is installed, roughly aligning the detector's zero point with the runway edge, and then repeatedly adjusting the chassis's installation angle to align the detector's zero point with the runway's horizontal direction. While quick, visual calibration suffers from poor accuracy and inconsistent zero-points between multiple detectors, with deviations typically between -5 and 5°. This results in inconsistent detection ranges for multiple detectors, creating blind spots and significant errors in locating foreign objects. Therefore, improving the flexibility and practicality of calibration to meet the accuracy requirements of airport runway FOD detectors is a pressing issue. Summary of the Invention

[0005] In view of this, the present invention provides a method for calibrating the zero position of an FOD detector based on radar imaging in an airport, which can meet the calibration accuracy requirements of external detectors on airport runways, including:

[0006] Step 1: Install and set up detectors according to the airport road type, and select reference points accordingly;

[0007] Step 2: Set scanning parameters and control the detection radar to perform site survey scanning; acquire a one-dimensional distance image of the airport road and upload it to the host computer via the network;

[0008] Step 3: The host computer marks the position of the reference point based on the one-dimensional distance image of the airport road;

[0009] Step 4: The detector is zero-point calibrated by operating the detector to obtain the actual zero-point deviation value.

[0010] Specifically, when the airport road type is a runway, the detector is fixed horizontally to the runway edge line by visual inspection; the detectors are symmetrically installed on both sides of the runway, and the detector on one side of the runway is selected with the detector on the other side of the runway as a reference point.

[0011] Specifically, when the airport road type is a connecting road, the zero-degree position of the detector is oriented towards the same-side side light angle by visual method, and the same-side runway side light is selected as the reference point.

[0012] Specifically, setting scanning parameters and controlling the detection radar to perform field survey scanning includes configuring scanning parameters to perform forward and reverse field survey scanning from 0 to 180°.

[0013] Specifically, when the road type is a runway, marking the location of the opposing detector includes: analyzing the forward one-dimensional range image acquired by the radar, using a marking tool to mark the maximum echo power of the opposing detector, and obtaining the azimuth angle.

[0014] Specifically, the actual zero point of the detector is θ, and the actual installation angle of the opposing detector is 90°; the average angle values ​​of the opposing detectors during forward and reverse scanning are denoted as θ. 1。 Then the angular deviation θ2 = 90 - θ1;

[0015] When θ2 < 0, the detector's zero-position angle is deflected to the left; when θ2 > 0, the detector's zero-position angle is deflected to the right; when θ2 = 0, it means the detector's zero-position angle has no deviation, therefore:

[0016]

[0017] Specifically, when the road type is a connecting road, the radar one-dimensional range image obtained by analysis is used to label the runway edge lights on the same side according to the azimuth angle, range and echo power.

[0018] Specifically, obtaining the actual zero-point deviation value of the detector includes:

[0019] The detector's actual zero position is θ, and the reference runway edge light on the same side is 0°. The average angle values ​​of the runway edge lights from both forward and reverse scans are recorded as θ1. Then the angle deviation θ2 = 0 – θ1;

[0020] When θ2 < 0, the detector's zero-position angle is deflected to the left; when θ1 > 0, the detector's zero-position angle is deflected to the right; θ2 = 0 indicates that the detector's zero-position angle has no deviation; since the detector is installed directly in front of the side lamp, and the distance between them is denoted as R, the actual zero-position θ is:

[0021]

[0022] Specifically, step 4 includes:

[0023] Control the detector to operate at position θ, and use the host computer to set this angle to zero degrees to complete the zero-position calibration of the detector.

[0024] Beneficial effects:

[0025] 1) This invention can effectively solve the impact of visual calibration on detection accuracy and greatly improve the flexibility and practicality of calibration; the calibration measurement error is within 0.4°, which can meet the calibration accuracy requirements of external detectors on airport runways;

[0026] 2) This invention can be used for various types of airport roads, including runways and connecting taxiways;

[0027] 3) This invention uses the radar one-dimensional range image obtained through analysis to mark the runway edge lights on the same side or the detectors on the opposite side according to the azimuth angle, range and echo power. It has good accuracy and wide applicability.

[0028] 4) The present invention allows for setting scanning parameters to control the detection radar to perform field scanning, providing high flexibility and applicability to various scenarios;

[0029] 5) This invention can be applied to calculate the actual zero position of the detector in various scenarios to obtain different angular offsets;

[0030] 6) In this invention, the detector is controlled to operate at position θ, and the host computer sets this angle to zero degrees to complete the zero-position calibration of the detector. This method is highly reliable and easy to operate. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the installation and deployment of detectors in an airport runway according to the present invention;

[0032] Figure 2 This is a schematic diagram of the installation and deployment of the detector in the airport connecting taxiway in this invention;

[0033] Figure 3 This is a schematic diagram of a one-dimensional range image of a symmetrical detector being scanned in this invention;

[0034] Figure 4 This is a schematic diagram illustrating the angle of the runway marking opposing detector in this invention;

[0035] Figure 5 This is a schematic diagram showing the angle of the opposing detector deviation direction in this invention;

[0036] Figure 6 This is a schematic diagram for reference to the side lights of the detector installed in the connecting road in this invention;

[0037] Figure 7 This is a schematic diagram of a one-dimensional distance image of the same-side lamp scanned in this invention;

[0038] Figure 8 This is a schematic diagram illustrating the angle of the side lights on the connecting roadway in this invention; Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] This invention provides a method for marking the zero position of a detector in an airport based on radar imaging. After the detector is visually installed, a reference angle is selected again using radar imaging for zero-position calibration. This description explains the implementation principle, which is used to correct the zero-position error during detector installation, greatly improving the accuracy of the detector's zero position and meeting the accuracy requirements of detector calibration. The specific implementation method is as follows:

[0041] Example 1: Calibration method for detectors symmetrically installed on both sides of the runway

[0042] Step 1: Install and set up detectors according to the airport road type, and select reference points accordingly;

[0043] In this embodiment, the airport road type is a runway. First, the zero position of the detector is roughly level with the runway edge line by visual inspection. Then, the chassis is fixed. At this time, the zero position of the detector is roughly level with the runway edge line. Detectors are installed symmetrically on both sides of the runway, and the detector on the opposite side is selected as the reference point.

[0044] Step 2: The detection radar performs a field scan.

[0045] Once the detectors are installed, the scanning scene is fixed. Since the detectors are symmetrically installed on the runway, and their installation positions have been measured using standard measurement methods;

[0046] Therefore, the theory assumes that the two detectors symmetrically mounted on either side of the runway are at approximately 90° to each other. The scanning parameters are configured to 0-180° for forward and reverse field reconnaissance scanning. The one-dimensional range image of the current runway scene is transmitted back to the host computer software via the network. This scanned one-dimensional range image is used to mark the positions of the symmetrical detectors, such as... Figure 3 As shown.

[0047] Step 3: The host computer marks the position of the reference point based on the one-dimensional distance image of the airport road.

[0048] The forward one-dimensional range image acquired by the radar is analyzed, and the maximum echo power of the opposing detector is marked using a labeling tool to obtain the azimuth angle. For example... Figure 4 As shown, the x-axis represents the azimuth angle (unit: °), the y-axis represents the distance (unit: m), and the z-axis represents the scene echo power (unit: dBm). Figure 4 For example, "X 88.17°" is the measured angle value of the facing detector. The same method is used to mark the angle values ​​of the facing detector in the radar's reverse one-dimensional range image.

[0049] Step 4: The detector is zero-point calibrated by operating the detector to obtain the actual zero-point deviation value.

[0050] The actual zero point of the detector is θ, and the actual installation angle of the opposing detector is 90°; the average angle values ​​of the opposing detectors during forward and reverse scanning are denoted as θ. 1。 Then the angular deviation θ2 = 90 - θ1.

[0051] When θ2 < 0, the detector's zero-position angle is deflected to the left; when θ2 > 0, the detector's zero-position angle is deflected to the right; θ2 = 0 indicates that the detector's zero-position angle has no deviation. Therefore:

[0052]

[0053] Deviation such as Figure 5 As shown.

[0054] Subsequently, the detector is controlled to operate at position θ, and this angle is set to zero degrees by the host computer to complete the zero-position calibration of the detector.

[0055] Example 2: Zero-position calibration method for detectors installed in connecting tunnels

[0056] Step 1: Install and set up detectors according to the airport road type, and select reference points accordingly;

[0057] In this embodiment, the airport road type is a connecting road.

[0058] The zero-degree position of the detector is visually aligned with the 60m edge light on the same side. The installation method involves first visually aligning the detector's zero position roughly horizontally with the runway edge line, then fixing the chassis. At this point, the detector's zero position is approximately horizontal with the runway edge line. Since there are no symmetrical reference detectors for the runway-connecting track, the runway edge light at 60m on the same side (typically installed at a distance of 60m) is used as the reference point. Figure 6 As shown.

[0059] Step 2: The detection radar performs a field scan.

[0060] The field survey scanning method is the same as in 2.2); the one-dimensional distance image obtained from the field survey scanning is as follows: Figure 7 As shown.

[0061] At this point, the scanning parameters are configured to 0-180° for forward and reverse field surveying. The one-dimensional distance image of the current connecting road scene will be transmitted back to the host computer software via the network. The scanned one-dimensional distance image is used to mark the positions of the side lights, such as... Figure 7 As shown.

[0062] Step 3: The host computer marks the reference point, i.e., the position of the side light, based on the one-dimensional distance image of the airport road.

[0063] The obtained one-dimensional radar range profile is analyzed, where the x-axis represents the azimuth angle (unit: °), the y-axis represents the range (unit: m), and the z-axis represents the scene echo power (unit: dBm). For example... Figure 8 As shown.

[0064] Step 4: The detector is zero-point calibrated by operating the detector to obtain the actual zero-point deviation value.

[0065] The detector's actual null position is θ, and the reference runway edge light on the same side is 0°. The average angle values ​​of the runway edge lights from both forward and reverse scans are recorded as θ. 1。 Then the angular deviation θ2 = 0 – θ1.

[0066] When θ2 < 0, the detector's zero-position angle is deflected to the left; when θ1 > 0, the detector's zero-position angle is deflected to the right; θ2 = 0 indicates that the detector's zero-position angle has no deviation. Since the detector is installed directly in front of the side light, and the distance between them is denoted as R, the actual zero-position θ is:

[0067]

[0068] Control the detector to operate at position θ, and use the host computer to set this angle to zero degrees to complete the zero-position calibration of the detector.

[0069] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0070] It will be apparent to those skilled in the art that the embodiments of the present invention are not limited to the details of the exemplary embodiments described above, and that the embodiments of the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the embodiments of the present invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the embodiments of the present invention is defined by the appended claims rather than the foregoing description. Therefore, all variations falling within the meaning and scope of equivalents of the claims are intended to be encompassed within the embodiments of the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units, modules, or devices recited in the system, apparatus, or terminal claims may also be implemented by the same unit, module, or device through software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any particular order.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit them. Although the embodiments of the present invention have been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the embodiments of the present invention should not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of calibrating a zero position of a FOD detector based on radar imaging in an airport, characterized in that, The method comprises the following steps: Step 1, installing the detector according to the type of airport road and selecting the reference point accordingly; when the type of airport road is runway, fixing the detector horizontally to the runway boundary line by visual method; installing the detector symmetrically on both sides of the runway, and selecting the detector on one side of the runway as the reference point of the detector on the other side of the runway; when the type of airport road is taxiway, fixing the detector by visual method with the zero position angle of the same side boundary light, and selecting the same side runway boundary light as the reference point; Step 2, configuring the scanning parameter as 0-180°, controlling the detection radar to scan the runway forward and backward, and obtaining the one-dimensional range image of the airport road and uploading the one-dimensional range image to the upper computer through the network; Step 3, marking the position of the reference point according to the one-dimensional range image of the airport road; when the type of airport road is runway, marking the position of the opposite detector includes: analyzing the forward and backward one-dimensional range image collected by the radar, marking the maximum echo power of the opposite detector by using the marking tool, and obtaining the azimuth angle; when the type of airport road is taxiway, analyzing the radar one-dimensional range image, and marking the same side runway boundary light according to the azimuth angle, the distance and the echo power; Step 4, obtaining the actual zero position of the detector according to different types of airport roads, running the detector to the actual zero position, and setting the actual zero position as zero degree through the upper computer to complete the zero calibration of the detector.

2. The method of calibrating a zero position of a FOD detector based on radar imaging at an airport as recited in claim 1, wherein, When the type of road is runway, the actual zero position of the detector is θ, and the actual installation angle of the opposite detector is 90°; the average of the angle values of the opposite detector scanned forward and backward is recorded as θ1, and the angle deviation θ2 = 90 - θ1; When θ2 < 0, the zero angle of the detector deviates to the left; when θ2 > 0, the zero angle of the detector deviates to the right; θ2 = 0 indicates that the zero angle of the detector has no deviation, and thus: 。 3. The method of calibrating a zero position of a FOD detector based on radar imaging at an airport as recited in claim 1, wherein: When the type of road is taxiway, the actual zero position deviation of the detector includes: The actual zero position of the detector is θ, the same side runway boundary light is 0°, the average of the angle values of the same side runway boundary light scanned forward and backward is recorded as θ1, and the angle deviation θ2 = 0 - θ1; When θ2 < 0, the zero angle of the detector deviates to the left; when θ1 > 0, the zero angle of the detector deviates to the right; θ2 = 0 indicates that the zero angle of the detector has no deviation; since the detector is installed in front of the boundary light, the distance between them is R, and thus the actual zero position θ is: 。

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