Device and method for automatically calibrating photoelectric marker based on space vector measurement

Abstract

The invention relates to the technical field of antenna calibration, in particular to an automatic photoelectric marker calibration device and method based on space vector measurement, and the device comprises a tripod, an azimuth pitching two-dimensional precision turntable, a laser range finder, a monitoring camera and an upper computer. The azimuth pitching two-dimensional precision rotary table is fixedly installed on the tripod, the laser range finder is fixedly installed on the azimuth pitching two-dimensional precision rotary table, and the upper computer is electrically connected with the azimuth pitching two-dimensional precision rotary table, the laser range finder and the monitoring camera; the azimuth pitching two-dimensional precision turntable is a two-dimensional precision turntable driven by an ultrasonic motor; the laser range finder is a telescope type one-dimensional laser range finder; the monitoring camera is a rotatable pan-tilt camera; the upper computer is a computer; the problems of low efficiency and poor precision of large-spacing manual operation in the existing photoelectric mark calibration technology are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of antenna calibration, and in particular to a device and method for automatic calibration of a photoelectric marker based on space vector measurement. Background Art

[0002] The Cassegrain antenna is a dual-reflector antenna with excellent telecommunications and structural advantages, and is widely used in radio tracking and measurement systems. Radio tracking and measurement equipment can precisely locate and track targets. To ensure the accuracy of radio tracking measurements, the Cassegrain antenna's electrical axis must be aligned with the target and maintained stable. Therefore, calibration and correction of the Cassegrain antenna's electrical axis are crucial for improving tracking and measurement accuracy. The electrical axis refers to the direction of the Cassegrain antenna's beam at maximum signal strength. Precise determination of the electrical axis can be challenging due to factors such as noise and beam width.

[0003] To facilitate determination and observation of the electrical axis, a low-light-level television (LLITV) is typically placed at a fixed position on the antenna. Initially, the LLITV optical axis is aligned parallel to the antenna's mechanical axis. Once the relative physical dimensions of the two axes are determined, the LLITV optical axis can be used to represent the antenna's mechanical axis. Simultaneously, the antenna's electrical axis and mechanical axis are aligned as closely as possible, ensuring they are also parallel to the LLITV optical axis. On a calibration tower that meets far-field conditions, a comprehensive optoelectronic target mount is set up on a plane perpendicular to the LLITV optical axis, aligned with the relative dimensions of the antenna's mechanical axis and the LLITV optical axis. This mount consists of an antenna (the "beacon") that transmits calibration signals and a point light source (the "cursor"). This is commonly referred to as an optoelectronic target. The relative dimensional accuracy of the optoelectronic target determines the absolute stability of the tracking radar's electrical axis. Its relative dimensional relationship must strictly conform to the relative dimensions of the radar's electrical and optical axes. When the antenna points to the cursor, the electrical axis must be parallel to the optical axis and pointed toward the target.

[0004] However, for large Cassegrain antennas, when far-field conditions are met, the distance between the optoelectronic target mount and the antenna increases significantly, and the distance between the cursor and the target also increases. Existing technologies rely on manual measurement and adjustment of the relative position of the optoelectronic target, which has two major drawbacks: first, manual operation is extremely inconvenient at large distances, resulting in low calibration efficiency; second, due to the accuracy of the measurement tool and environmental interference such as vibration and line of sight obstruction, it is difficult to ensure that the relative position and size of the cursor and target meet the requirements of high-precision calibration, thus affecting the reliability of the antenna's electric axis stability measurement.

[0005] Therefore, it is necessary to invent a photoelectric marker relative position calibration device and a method of using the same to solve the above problems. Summary of the Invention

[0006] In order to solve the problems of low efficiency and poor precision in large-interval manual operation in the existing photoelectric marker calibration technology, the present invention provides a device and method for automatic calibration of a photoelectric marker based on space vector measurement.

[0007] The present invention is achieved by adopting the following technical solutions:

[0008] An automatic calibration device for a photoelectric marker based on space vector measurement includes a tripod, an azimuth-pitch two-dimensional precision turntable, a laser rangefinder, a monitoring camera, and a host computer;

[0009] The azimuth and pitch two-dimensional precision turntable is fixedly installed on a tripod, the laser rangefinder is fixedly installed on the azimuth and pitch two-dimensional precision turntable, and the host computer is electrically connected to the azimuth and pitch two-dimensional precision turntable, the laser rangefinder and the surveillance camera respectively.

[0010] Furthermore, the azimuth and pitch two-dimensional precision turntable is a two-dimensional precision turntable driven by an ultrasonic motor.

[0011] Furthermore, the laser rangefinder is a telescopic one-dimensional laser rangefinder.

[0012] Furthermore, the surveillance camera is a rotatable pan-tilt camera.

[0013] Furthermore, the host computer is a computer.

[0014] A method for automatically calibrating a photoelectric marker based on space vector measurement is provided. The method is implemented based on the device for automatically calibrating a photoelectric marker based on space vector measurement described in the present invention. The method is implemented by the following steps:

[0015] S1: After installing the tripod, azimuth and elevation two-dimensional precision turntable and laser rangefinder, set them up between the Cassegrain antenna and the optoelectronic target mount, making sure that they are at the same distance from the Cassegrain antenna and the optoelectronic target mount and that there are no obstructions in the line of sight.

[0016] S2: The azimuth and pitch two-dimensional precision turntable is controlled by the host computer to adjust the azimuth and pitch angles of the laser rangefinder, so that the laser rangefinder points to the center point A1 of the low-light-level TV on the Cassegrain antenna, the center point B1 of the antenna feed of the Cassegrain antenna, the cursor point A2 on the photoelectric target stand, and the center point B2 of the electric mark on the photoelectric target stand, and the distance information and angle information of these four points relative to the laser rangefinder are collected in sequence. At the same time, the azimuth and pitch two-dimensional precision turntable and the laser rangefinder are monitored by the surveillance camera, and the azimuth and pitch two-dimensional precision turntable is assisted to adjust the azimuth and pitch angles of the laser rangefinder to play a guiding and confirming role. The host computer synchronously records the angle information collected by the azimuth and pitch two-dimensional precision turntable and the distance information collected by the laser rangefinder;

[0017] S3: The host computer calculates the vector from the center point A1 of the low-light-level TV to the cursor point A2 on the photoelectric target frame through the angle information collected by the azimuth and pitch two-dimensional precision turntable and the distance information collected by the laser rangefinder. The vector from the center point B1 of the antenna feed to the center point B2 of the photoelectric target stand

[0018] S4: Calculate vector through host computer and The cross product result and judge Whether parallel if and The cross product result is less than the set threshold, which means and If the cursor point A2 on the photoelectric target holder and the center point B2 on the photoelectric target holder are parallel, the relative position has reached the preset accuracy range, achieving high-precision automatic calibration. and The cross product result is greater than the set threshold, which means and If not parallel, execute step S5;

[0019] S5: According to the vector and The polar angle and azimuth angle are calculated by the host computer. and When the cross product result is 0, the position adjustment amount of the cursor point A2 on the photoelectric target frame and the center point B2 of the electric mark is adjusted. With the cooperation of the laser rangefinder, the positions of the cursor point A2 and the center point B2 on the photoelectric target frame are adjusted, and then steps S2 to S4 are repeated to re-collect data and perform a new round of calibration calculation until and The cross product result is less than the set threshold.

[0020] The present invention provides a device and method for automatic calibration of a photoelectric marker based on space vector measurement. The device uses a two-dimensional precision turntable in azimuth and elevation to obtain angle information of the center point of a low-light-level television on a Cassegrain antenna, the center point of an antenna feed source of the Cassegrain antenna, a cursor point on a photoelectric target stand, and the center point of the electric marker. Furthermore, a laser rangefinder is used to obtain distance information corresponding to these four points. Based on this, the relative position of the photoelectric marker can be calibrated through space vector calculation and position adjustment of the cursor point and the center point of the electric marker. The device has a clear and simple principle and is easy to operate. It not only simplifies the operating process and improves the calibration efficiency of the photoelectric marker, but also has flexible application and convenient adjustment, effectively avoiding the problems of low efficiency and poor precision of manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a structural schematic diagram of the present invention.

[0022] Figure 2 It is a schematic diagram of the calibration method principle of the present invention.

[0023] In the figure: 1. Tripod; 2. Azimuth and elevation two-dimensional precision turntable; 3. Laser rangefinder; 4. Surveillance camera; 5. Host computer; 6. Cassegrain antenna; 7. Optoelectronic target mount; 8. Low-light-level television; 9. Antenna feed. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1

[0026] An automatic calibration device for photoelectric markers based on space vector measurement, as shown in the attached Figure 1 As shown, it includes a tripod 1, an azimuth and pitch two-dimensional precision turntable 2, a laser rangefinder 3, a monitoring camera 4 and a host computer 5;

[0027] The azimuth-pitch two-dimensional precision turntable 2 is fixedly mounted on the tripod 1, the laser rangefinder 3 is fixedly mounted on the azimuth-pitch two-dimensional precision turntable 2, and the host computer 5 is electrically connected to the azimuth-pitch two-dimensional precision turntable 2, the laser rangefinder 3 and the surveillance camera 4 respectively.

[0028] The azimuth and elevation two-dimensional precision turntable 2 is a two-dimensional precision turntable driven by an ultrasonic motor. The two-dimensional precision turntable driven by an ultrasonic motor is a prior art and will not be described in detail here.

[0029] The laser rangefinder 3 is a telescopic one-dimensional laser rangefinder.

[0030] The monitoring camera 4 is a rotatable pan / tilt camera.

[0031] The host computer 5 is a computer.

[0032] In the present invention, the tripod 1 is a support mechanism for supporting the azimuth-pitch two-dimensional precision turntable 2; the azimuth-pitch two-dimensional precision turntable 2 is used to install a laser rangefinder 3 and simultaneously obtain accurate angle information of the turntable's azimuth-pitch two-degree-of-freedom; the laser rangefinder 3 is a distance measuring instrument used to obtain the distance between the laser rangefinder 3 and the target when pointing at the target; the host computer 5 is a monitoring host, used to receive instructions to control the azimuth-pitch two-dimensional precision turntable 2 to rotate so that the laser rangefinder 3 is pointed at the target. When the laser rangefinder 3 is aligned with the target, it is used to read the angle information collected by the azimuth-pitch two-dimensional precision turntable 2 and the distance information collected by the laser rangefinder 3, calculate the vector cross product result and the calibration angle information of the relative position of the cursor point and the center point of the electric mark on the photoelectric target frame 7 according to the instructions, and simultaneously serve as a monitor for the monitoring camera 4 to control the direction of the monitoring camera 4; the monitoring camera 4 is used to guide the laser rangefinder 3 to point to the target and confirm whether the laser rangefinder 3 is accurately aimed at the target. In addition, it can also cooperate with the photoelectric target frame 7 to adjust the position of the cursor point or the center point of the electric mark.

[0033] Example 2

[0034] A method for automatic calibration of a photoelectric marker based on space vector measurement is implemented by the following steps:

[0035] S1: As attached Figure 1 ~Attachment Figure 2 As shown, the tripod 1, the azimuth and elevation two-dimensional precision turntable 2 and the laser rangefinder 3 are installed and set up between the Cassegrain antenna 6 and the photoelectric target stand 7, so that they are at the same distance from the Cassegrain antenna 6 and the photoelectric target stand 7, and there are no obstacles in the line of sight.

[0036] It should be noted that, in this embodiment, the center point of the laser rangefinder 3 is the coordinate point O, the Z axis is the axis passing through point O and perpendicular to the azimuth plane of the azimuth and pitch two-dimensional precision turntable 2, the X axis is the axis passing through point O and pointing to the azimuth zero point of the azimuth and pitch two-dimensional precision turntable 2, and the Y axis is the axis perpendicular to the XZ plane in accordance with the right-hand rule.

[0037] S2: The upper computer 5 controls the azimuth and pitch two-dimensional precision turntable 2 to adjust the azimuth and pitch angle of the laser rangefinder 3, so that the laser rangefinder 3 points to the center point A1 of the low-light-level TV 8 on the Cassegrain antenna 6, the center point B1 of the antenna feed source 9 of the Cassegrain antenna 6, the cursor point A2 on the photoelectric target frame 7, and the center point B2 of the electric mark on the photoelectric target frame 7 in sequence, and collects the distance information and angle information of these four points relative to the laser rangefinder 3 in sequence. At the same time, the azimuth and pitch two-dimensional precision turntable 2 and the laser rangefinder 3 are monitored by the monitoring camera 4, and the azimuth and pitch two-dimensional precision turntable 2 is assisted to adjust the azimuth and pitch angle of the laser rangefinder 3, which plays a role of guidance and confirmation. The upper computer 5 synchronously records the angle information collected by the azimuth and pitch two-dimensional precision turntable 2 and the distance information collected by the laser rangefinder 3.

[0038] S3: The host computer 5 calculates the vector from the center point A1 of the low-light TV 8 to the cursor point A2 on the photoelectric target frame 7 through the angle information collected by the azimuth and pitch two-dimensional precision turntable 2 and the distance information collected by the laser rangefinder 3 The vector from the center point B1 of the antenna feed source 9 to the center point B2 of the photoelectric target frame 7

[0039] It should be noted that, in the spherical coordinate system, when the laser rangefinder 3 accurately points to the center point A1 of the low-light-level TV 8, the vector is recorded as in is the spherical coordinate unit vector, r a1 is the vector modulus, θ a1 is the complementary angle of the polar angle, φ a1 is the azimuth; when the laser rangefinder 3 accurately points to the center point B1 of the antenna feed 9, the vector is where r b1 is the vector modulus, θ b1 is the complementary angle of the polar angle, φ b1 is the azimuth; when the laser rangefinder 3 accurately points to the cursor point A2, the vector is where r a2 is the vector modulus, θ a2 is the complementary angle of the polar angle, φ a2 is the azimuth; when the laser rangefinder 3 accurately points to the center point B2 of the electric mark, the vector is where r b2 is the vector modulus, θ b2 is the complementary angle of the polar angle, φ b2 is the azimuth.

[0040] Vector operations in spherical coordinates:

[0041]

[0042] S4: Calculate vector through host computer 5 and The cross product result and judge Whether parallel if and The cross product result is less than the set threshold R, which means and If the relative position of the cursor point A2 on the photoelectric target frame 7 and the center point B2 of the electric mark on the photoelectric target frame 7 is within the preset accuracy range, high-precision automatic calibration is achieved; and The cross product result is greater than the set threshold R, which means and If they are not parallel, execute step S5.

[0043] S5: According to the vector and The polar angle and azimuth angle are calculated by the host computer 5. and When the cross product result is 0, the position adjustment amount of the cursor point A2 and the center point B2 of the photoelectric target frame 7 is adjusted. With the cooperation of the laser rangefinder 3, the positions of the cursor point A2 and the center point B2 of the photoelectric target frame 7 are adjusted, and then steps S2 to S4 are repeated to re-collect data and perform a new round of calibration calculation until and The cross product result is less than the set threshold R.

[0044] In the description of the present invention, it should be understood that the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An automatic calibration device for a photoelectric marker based on space vector measurement, characterized by: It includes a tripod (1), an azimuth and pitch two-dimensional precision turntable (2), a laser rangefinder (3), a monitoring camera (4) and a host computer (5); The azimuth-pitch two-dimensional precision turntable (2) is fixedly mounted on a tripod (1); the laser rangefinder (3) is fixedly mounted on the azimuth-pitch two-dimensional precision turntable (2); and the host computer (5) is electrically connected to the azimuth-pitch two-dimensional precision turntable (2), the laser rangefinder (3) and the monitoring camera (4) respectively.

2. The automatic calibration device for photoelectric markers based on space vector measurement according to claim 1, characterized in that: The azimuth and pitch two-dimensional precision turntable (2) is a two-dimensional precision turntable driven by an ultrasonic motor.

3. The automatic calibration device for photoelectric markers based on space vector measurement according to claim 1, characterized in that: The laser rangefinder (3) is a telescopic one-dimensional laser rangefinder.

4. The automatic calibration device for photoelectric markers based on space vector measurement according to claim 1, characterized in that: The monitoring camera (4) is a rotatable pan-tilt camera.

5. The automatic calibration device for photoelectric markers based on space vector measurement according to claim 1, characterized in that: The host computer (5) is a computer.

6. A method for automatically calibrating a photoelectric marker based on space vector measurement, the method being implemented based on the device for automatically calibrating a photoelectric marker based on space vector measurement according to any one of claims 1 to 5, characterized in that: This method is implemented using the following steps: S1: After the tripod (1), the azimuth and elevation two-dimensional precision turntable (2) and the laser rangefinder (3) are installed, they are set up between the Cassegrain antenna (6) and the photoelectric target stand (7), so that the distances between them and the Cassegrain antenna (6) and the photoelectric target stand (7) are the same and there are no obstructions in the sight line; S2: The azimuth and pitch two-dimensional precision turntable (2) is controlled by the host computer (5) to adjust the azimuth and pitch angle of the laser rangefinder (3), so that the laser rangefinder (3) is pointed to the center point A1 of the low-light television (8) on the Cassegrain antenna (6), the center point B1 of the antenna feed source (9) of the Cassegrain antenna (6), the cursor point A2 on the photoelectric target frame (7), and the electric mark center point B2 on the photoelectric target frame (7), and the distance information and angle information of these four points relative to the laser rangefinder (3) are collected in sequence. At the same time, the azimuth and pitch two-dimensional precision turntable (2) and the laser rangefinder (3) are monitored by the monitoring camera (4), and the azimuth and pitch two-dimensional precision turntable (2) is assisted to adjust the azimuth and pitch angle of the laser rangefinder (3), which plays a role of guidance and confirmation. The host computer (5) synchronously records the angle information collected by the azimuth and pitch two-dimensional precision turntable (2) and the distance information collected by the laser rangefinder (3); S3: The host computer (5) calculates the vector from the center point A1 of the low-light television (8) to the cursor point A2 on the photoelectric target frame (7) through the angle information collected by the azimuth and pitch two-dimensional precision turntable (2) and the distance information collected by the laser rangefinder (3). The vector of the center point B1 of the antenna feed source (9) pointing to the center point B2 of the photoelectric target frame (7) S4: Calculate vector through host computer (5) and The cross product result and judge Whether parallel if and The cross product result is less than the set threshold, which means and If the relative positions of the cursor point A2 on the photoelectric target frame (7) and the center point B2 of the electric mark on the photoelectric target frame (7) are parallel, it indicates that the relative positions of the cursor point A2 on the photoelectric target frame (7) and the electric mark center point B2 on the photoelectric target frame (7) have reached the preset accuracy range, and high-precision automatic calibration is achieved; and The cross product result is greater than the set threshold, which means and If not parallel, execute step S5; S5: According to the vector and The polar angle and azimuth angle of the upper computer (5) are calculated and given and When the cross product result is 0, the position adjustment amount of the cursor point A2 and the center point B2 of the electric mark on the photoelectric target frame (7) is adjusted, and the positions of the cursor point A2 and the center point B2 of the electric mark on the photoelectric target frame (7) are adjusted in cooperation with the laser rangefinder (3), and then steps S2 to S4 are repeated to re-collect data and perform a new round of calibration calculation until and The cross product result is less than the set threshold.

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