Azimuth angle correction method of infrared search equipment

Abstract

The invention relates to an azimuth angle correction method of infrared search equipment, which comprises the following steps: acquiring inertial navigation data in real time, and superposing the inertial navigation data into image data of the infrared search equipment; carrying out geodetic coordinate system angle calculation by utilizing azimuth and pitch encoder information and inertial navigation data in the image to obtain geodetic coordinate system azimuth and pitch angles of the image; and correcting the solved azimuth angle to eliminate an error caused by an included angle between the optical axis of the equipment and the orientation of the equipment. The method is suitable for a composite detection scene in which infrared equipment and multiple sensors cooperatively work, and solves the problem of azimuth angle error caused by an included angle between the optical axis of the infrared equipment and the orientation of the equipment, thereby obtaining a more accurate geodetic coordinate system angle, and effectively improving the precision of target positioning, target fusion and guiding.

Description

Technical Field

[0001] The present invention relates to the technical field of coordinate angle calculation, and relates to a method for correcting the azimuth angle of an infrared search device. Background Art

[0002] Infrared search devices have a wide range of applications in target detection, tracking, and guidance. In actual applications and structural designs, there may be an angle between the optical axis of the infrared search device and the device's orientation. This characteristic can cause azimuth angle errors and affect the target positioning accuracy in the geodetic coordinate system. In multi-sensor collaborative work, azimuth angle errors will further reduce the system's target fusion and guidance performance.

[0003] In the prior art, the geodetic coordinate calculation is usually carried out by combining the device azimuth and pitch encoder data with the inertial navigation device data, ignoring the angle error problem caused by the angle between the optical axis and the pitch direction. As a result, the azimuth angle calculated during the 360-degree azimuth scan of the device is deviated, and the deviation is larger when the device's pitch angle is higher. To address this deficiency, an effective correction method is urgently needed to improve the target positioning accuracy of the infrared search device, thereby enhancing the system's target fusion and guidance performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for correcting the azimuth angle of an infrared search device, which solves the problem that in the prior art, the geodetic coordinate calculation is usually carried out by combining the device azimuth and pitch encoder data with the inertial navigation device data, ignoring the angle error problem caused by the angle between the optical axis and the pitch direction.

[0005] To achieve the above purpose, the technical solution of the present invention is:

[0006] A method for correcting the azimuth angle of an infrared search device, the infrared search device includes a servo control turntable and an infrared camera, the servo control turntable is a two-axis turntable including an azimuth axis and a pitch axis, or a three-axis turntable including an azimuth axis, a pitch axis, and a roll axis; the steps of the method for correcting the azimuth angle of the device are:

[0007] Step 1, obtain inertial navigation data in real time and superimpose it on the image data of the infrared search device;

[0008] Step 2, use the azimuth and pitch encoder information and inertial navigation data in the image to perform geodetic coordinate system angle calculation to obtain the geodetic coordinate system azimuth angle θ c0 and pitch angle β;

[0009] Step 3, correct the calculated azimuth angle to obtain the correct azimuth angle θ c1 .

[0010] The inertial navigation data in Step 1 includes azimuth angle, pitch angle, roll angle, azimuth angular velocity, pitch angular velocity, and roll angular velocity information.

[0011] In Step 3, the azimuth angle correction adopts the following formula:

[0012] θ c1 = θ c0 + Arctan(tanα / cosβ),

[0013] where, θ c1 is the azimuth angle in the geodetic coordinate system after correction, θ c0 is the azimuth angle in the geodetic coordinate system of the initial solution, α is the included angle between the optical axis of the device and the device orientation, and β is the forward pitch angle of the device.

[0014] The advantages of the present invention are as follows: 1. By combining inertial navigation data and infrared image data, calculating the azimuth and pitch angles in the geodetic coordinate system based on azimuth and pitch encoder data and inertial navigation data, and further correcting the calculated azimuth angle to reduce errors and improve the accuracy of target positioning; 2. Eliminating the azimuth angle error caused by the included angle between the optical axis of the infrared search device and the device orientation; improving the accuracy of target positioning, enhancing the target fusion and guidance performance of the system, which is of great significance; 3. This method is applicable to the composite detection scenario where the infrared device works in cooperation with multiple sensors, solves the problem of azimuth angle error caused by the included angle between the optical axis of the infrared device and the device orientation, thereby obtaining more accurate angles in the geodetic coordinate system, and effectively improving the accuracy of target positioning, target fusion, and guidance. Brief Description of the Drawings

[0015] Figure 1 is the flow schematic diagram of the present invention;

[0016] Figure 2 is the schematic diagram of the relationship between the optical axis of the infrared search device and the device orientation in the present invention. Detailed Embodiment

[0017] The following further describes the present invention with reference to the drawings. The drawings are only for illustrative purposes and should not be construed as a limitation to this patent.

[0018] For the sake of more concise description of this embodiment, some components that are well known to those skilled in the art but not relevant to the main content of this creation will be omitted in the drawings or description. In addition, for the convenience of expression, some components in the drawings will be omitted, enlarged, or reduced, but it does not represent the size or all structures of the actual product.

[0019] The present invention discloses a method for correcting the azimuth angle of an infrared search device. The infrared search device includes a servo control turntable and an infrared camera. The servo control turntable is a two-axis turntable including an azimuth axis and a pitch axis, or a three-axis turntable including an azimuth axis, a pitch axis and a roll axis. As Figure 1 shown, the steps of the method for correcting the azimuth angle of the device are as follows:

[0020] Step 1: Obtain inertial navigation data in real time and superimpose it on the image data of the infrared search device;

[0021] The inertial navigation data includes azimuth angle, pitch angle, roll angle, azimuth angular velocity, pitch angular velocity and roll angular velocity information.

[0022] Step 2: Use the azimuth and pitch encoder information in the image and the inertial navigation data to perform geodetic coordinate system angle calculation to obtain the geodetic coordinate system azimuth angle θ c0 and pitch angle β of the image;

[0023] The above coordinate calculation uses the coordinate calculation method of a conventional two-axis turntable or a three-axis turntable according to the device, and temporarily does not consider the angle between the optical axis of the infrared search device and the device orientation.

[0024] Step 3: Correct the calculated azimuth angle to obtain the correct azimuth angle θ c1 .

[0025] The azimuth angle correction uses the following formula:

[0026] θ c1 = θ c0 + Arctan(tanα / cosβ),

[0027] where θ c1 is the corrected geodetic system azimuth angle, θ c0 is the initially calculated geodetic system azimuth angle, α is the angle between the optical axis of the device and the device orientation, and β is the front pitch angle of the device.

[0028] In order to more clearly describe the relationship between the optical axis of the infrared search device and the device orientation angle, as Figure 2 shown, when the infrared search device is working normally, it scans azimuthally at a constant speed from 0 to 360 degrees, and the pitch is adjusted to different pitch positions according to requirements. Figure 2 Positions T / S and T' / S' in the figure are respectively schematic diagrams of two different positions during the scanning process of the infrared search device. When the pitch is horizontal, the device orientation is at the position shown by T, and the optical axis orientation is at the position shown by S. There is an angle α between the device orientation and the optical axis orientation. When the device pitches by an angle β, the device orientation is at the position shown by T', and when the pitch is horizontal, the optical axis orientation is at the position shown by S'. The angle α between the device orientation and the optical axis orientation remains unchanged.

[0029] The above are only the preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. That is, equivalent changes and modifications made to the content of the scope of patent application of the present invention shall fall within the technical scope of the present invention.

Claims

1. A method for correcting the azimuth angle of an infrared search device, the infrared search device comprising a servo-controlled turntable and an infrared camera, the servo-controlled turntable being a two-axis turntable including an azimuth axis and a pitch axis, or a three-axis turntable including an azimuth axis, a pitch axis and a roll axis; characterized in that: The steps of the azimuth angle correction method for the device are: Step 1: Acquire inertial navigation data in real time and superimpose it on the image data of the infrared search device; Step 2: Use the azimuth and pitch encoder information and inertial navigation data in the image to calculate the geodetic coordinate system angle and obtain the geodetic coordinate system azimuth angle θ of the image. c0 and pitch angle β; Step 3: Correct the calculated azimuth angle to obtain the correct azimuth angle θ c1 .

2. The azimuth angle correction method according to claim 1, characterized in that: The inertial navigation data in step one includes azimuth, pitch angle, roll angle, azimuth velocity, pitch velocity and roll velocity information.

3. The azimuth angle correction method according to claim 1, characterized in that: The azimuth angle correction in step 3 uses the following formula: i c1 =θ c0 +Arctan(tanα / cosβ), Among them, θ c1 is the corrected geodetic azimuth angle, θ c0 is the initial calculated geodetic azimuth angle, α is the angle between the device optical axis and the device orientation, and β is the pitch angle of the device.

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