Shafting installation error calibration method for photoelectric comprehensive monitoring equipment

Abstract

The invention provides a shafting installation error calibration method for photoelectric comprehensive monitoring equipment, the equipment adopts a common azimuth axis integrated design and comprises a plurality of coordinate systems from an optical axis to an IMU (Inertial Measurement Unit) body, and a plurality of groups of installation error angles exist among the coordinate systems. The method comprises the following steps: firstly, establishing a coordinate system conversion matrix and deducing and constructing a compensation model for decomposing height and azimuth measurement errors into constant zero offset and related items of a target height angle; on the basis of the model, aiming at the characteristics of different error terms, mechanical adjustment is adopted to eliminate negligible terms, digital calibration is carried out through combination of azimuth axis rotation modulation and IMU output calculation, external field zero calibration is carried out through RTK and a target, and finally systematic and high-precision compensation of all shaft system installation errors is achieved. According to the method, theoretical modeling and engineering practice are combined, the influence of complex shafting errors on the equipment precision is effectively eliminated, the measurement precision and reliability of the photoelectric comprehensive monitoring equipment are remarkably improved, and the method has systematicness and universality.

Description

Technical Field

[0001] This invention relates to the field of photoelectric monitoring technology, and in particular to a method for calibrating shaft installation errors in integrated photoelectric monitoring equipment. Background Technology

[0002] When a pontoon bridge vessel is constructing a pier at sea, it needs to monitor its relative position to the preceding vessel (the target vessel) in real time using its onboard positioning and monitoring equipment to ensure the successful connection of the pontoon bridge between the fore and aft slipways. The integrated optoelectronic monitoring equipment is crucial for positioning and monitoring during pier construction. This equipment integrates an inertial measurement unit and an optoelectronic tracking measurement unit, deeply fusing inertial attitude measurement data with optoelectronic ranging data. It provides real-time, high-precision measurements of the north, east, and vertical distances between the following vessels and the preceding vessel within the geographic frame. These measurements are then transmitted to the vessel's dynamic positioning system to accurately determine its position relative to the preceding vessel, ensuring the successful connection of the pontoon bridge to the designated location on the preceding vessel.

[0003] Photoelectric integrated monitoring equipment generally adopts a "pitch + azimuth" stabilization platform design. The photoelectric image sensor and laser rangefinder are mounted on the pitch axis, which is mounted on the upper end of the azimuth rotation axis. The equipment's inertial measurement unit (IMU) is mounted on the lower end of the azimuth rotation axis. The core sensors inevitably have installation errors between each other. Although these errors can be controlled to a small range during the equipment's structural design, they are still significant for high-precision monitoring equipment (for example, an installation error of 2 arcminutes between the azimuth direction of the IMU and the optical axis of the photoelectric image sensor will cause a measurement error of approximately 0.1 meters when measuring a target 180 meters away). Therefore, it is necessary to model and analyze the axis installation errors that affect the equipment's monitoring accuracy and eliminate their impact on the measurement accuracy. Summary of the Invention

[0004] This invention proposes a method for calibrating the shaft system installation error of photoelectric integrated monitoring equipment, which solves the problem of poor positioning accuracy caused by shaft system installation error in existing photoelectric integrated monitoring equipment.

[0005] The technical solution of this invention is implemented as follows: This invention provides a method for calibrating the shaft system installation error of a photoelectric integrated monitoring device. The device adopts a common-orientation shaft integrated design and includes an optical axis coordinate system. Pitch-rotation coordinate system Pitch axis zero coordinate system Azimuth rotation coordinate system and IMU body coordinate system The shaft system installation error includes: Optical axis coordinate system With pitch axis coordinate system Installation error angle between Pitch axis zero coordinate system With azimuth axis coordinate system Installation error angle between and the azimuth rotation coordinate system With IMU body coordinate system Installation error angle between ; The calibration method includes the following steps: Based on the aforementioned shaft system installation error, the target vector in the IMU body coordinate system is derived. The following height error angle Compensation model for azimuth error angle : ; in, This indicates the pitch axis zero-position deviation; This indicates the zero-position deviation of the azimuth axis; Indicates the pitch rotation axis and azimuth rotation axis at Y Non-perpendicularity of direction; Indicates the orientation rotation axis and the IMU body coordinate system Y The non-perpendicularity of the axis; Indicates the optical axis and the pitch and rotation axis at... Z Non-perpendicularity of direction; H The measured elevation angle of the target vector; Based on the aforementioned compensation model, respectively for , , , and All errors are eliminated or calibrated.

[0006] Specifically, the process of deriving the compensation model includes: Establish the direction cosine matrix transformation relationship between the coordinate systems as follows: Optical axis coordinate system To the pitch axis coordinate system The transformation matrix is: ; Pitch-rotation coordinate system To the pitch axis zero coordinate system The transformation matrix is: ; Pitch axis zero coordinate system To the azimuth coordinate system The transformation matrix is: ; Azimuth rotation coordinate system To IMU body coordinate system The transformation matrix is: ; in, It is the identity matrix. , , This represents the cross-product antisymmetric matrix constructed from the angular components of the installation errors of each coordinate system. Representing the coordinate system along X Axis rotation angle; When there is no shaft installation error, the target vector In the optical axis coordinate system The Chinese character is represented as The coordinates are transferred to the IMU body coordinate system via a coordinate system transformation matrix. , to obtain the target vector In the IMU body coordinate system The projection below is: and use the actual elevation angle of the target H and azimuth A express: ; When shaft installation errors exist, the target vector In the pitch axis coordinate system The Chinese character is represented as The coordinates are transferred to the IMU body coordinate system via a coordinate system transformation matrix. , to obtain the target vector In the IMU body coordinate system The projection below is: And use the actual measured elevation angle of the target and azimuth express: ; Height error angle introduced by shaft system error and azimuth error angle , and the measured elevation angle of the target and azimuth The relationship between them is: ; By combining the above formulas, the target vector is finally obtained. In the IMU body coordinate system The following height error angle Compensation model for azimuth error angle .

[0007] Specifically, the non-perpendicularity between the pitch rotation axis and the azimuth rotation axis Adjustments were made to eliminate The term error specifically includes: The perpendicularity of the pitch axis and azimuth axis is mechanically adjusted using the plumb line method or autocollimator method. During equipment assembly and adjustment, first adjust the pitch axis yaw rate to within 10 arcseconds and the azimuth axis yaw rate to within 5 arcseconds, then adjust the perpendicularity... The time is controlled within 20 arcseconds, ensuring that the device monitors the target elevation angle. H Within ±10°, The value of the term is less than 3.5 arcseconds, and therefore is ignored in error compensation.

[0008] Specifically, regarding the non-perpendicularity between the optical axis and the pitch rotation axis... Adjustments were made to eliminate The term error specifically includes: The perpendicularity of the optical axis to the pitch axis is mechanically adjusted using the upright and reverse mirror method; the non-perpendicularity is then corrected. The time is controlled within 15 arcseconds, ensuring that the device monitors the target elevation angle. H Within ±10°, The value of the term is less than 16 arcseconds, and therefore it is ignored in error compensation.

[0009] Specifically, the non-perpendicularity between the orientation rotation axis and the IMU body coordinate system Calibration and digital compensation are performed to eliminate The term error specifically includes: After placing the device still on the platform and completing IMU alignment, control the device to rotate its orientation axis 180°. The IMU-calculated roll angles of the carrier were obtained before and after the azimuth axis rotation. and pitch angle ; Calculate the step jump error of the carrier attitude before and after azimuth axis rotation and ; According to the formula: , Calculate the installation error angle ; The calculated The value is used as an error compensation parameter and is bound to the inertial measurement unit to compensate for the non-orthogonality error between the IMU body and the azimuth axis; Iteratively execute the above steps until the attitude step jump error is reached. and Approximately zero, thus achieving This allows the equipment to monitor the target elevation angle. H Within ±10° The value of the term is negligible.

[0010] Specifically, regarding the pitch axis zero-position deviation and azimuth axis zero position deviation Calibration and compensation are performed, specifically including: Photoelectric integrated monitoring equipment and target modules are set at two different locations. The front of the target module is provided with a crosshair for marking the center. An RTK base station was set up near the photoelectric integrated monitoring equipment, and an RTK rover station was used to accurately measure the first geodetic coordinates of the center point of the photoelectric integrated monitoring equipment. And the second geodetic coordinates of the center point of the crosshairs of the target module. ; Based on the WGS-84 Earth ellipsoid model, the first and second geodetic coordinates are converted into spatial rectangular coordinates, and the azimuth angle of the vector from the center point of the photoelectric integrated monitoring equipment to the target center in a spherical coordinate system with the equipment center point as the origin is further calculated. and horizontal pitch angle ; The photoelectric integrated monitoring equipment is controlled to aim at and track the center of the crosshairs of the target module, and the measured azimuth angle of the vector from the center point of the photoelectric integrated monitoring equipment to the center of the target in the northeast coordinate system is obtained. and measured pitch angle ; Calculate the zero-point deviation: , ; The calculated The error is input into the shaft system error calibration software module of the photoelectric integrated monitoring equipment to complete the software compensation for zero-position deviation.

[0011] Furthermore, the geodetic coordinates are converted to spatial rectangular coordinates and the azimuth angle in the spherical coordinate system is calculated. and pitch angle The methods include: Calculate the radii of curvature of the geodesic zone and the target point based on the WGS-84 ellipsoid parameters: ; in, a The major radius of the ellipsoid is e The first eccentricity; Spatial geodetic coordinates of the equipment site Convert to spatial rectangular coordinates : ; in, ; The spatial geodetic coordinates of the target Convert to spatial rectangular coordinates : ; in, ; The spatial rectangular coordinates of the target Convert to coordinates in the device site Cartesian coordinate system : ; in, , , ; The coordinates of the target in the Cartesian coordinate system of the device site Coordinates converted to the device site spherical coordinate system : Among them, azimuth angle The calculation formula is as follows: ; Pitch angle The calculation formula is as follows: ; in, ; The formula for calculating distance is: .

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) By establishing an accurate error compensation model, the present invention transforms the originally complex and difficult-to-measure mechanical installation deviation into a quantity that can be compensated by an algorithm. It also designs targeted separation, adjustment and calibration processes for error terms of different natures, thereby systematically and efficiently eliminating various shaft system installation errors and ultimately significantly improving the overall monitoring accuracy and reliability of the equipment. (2) This invention designs a clear and effective calibration method and precision control target for error terms that can be eliminated by mechanical calibration. Through a standardized mechanical assembly and calibration process, the non-perpendicularity between key shaft systems is controlled within a very small range, so that these error terms can be ignored in subsequent calculations. This not only reduces the complexity of the compensation algorithm, but also improves the long-term stability of the system. (3) For errors that cannot be completely eliminated by mechanical adjustment, the present invention innovatively designs a digital calibration method based on a specific motion sequence. By rotating the azimuth axis under static conditions and interpreting the IMU attitude output, the specific installation error angle can be accurately separated and calculated. Then, high-precision digital compensation is achieved through parameter binding, realizing software-based correction of complex errors. (4) The present invention designs a complete zero-position deviation field calibration system and process. By integrating high-precision differential satellite positioning technology (RTK) and professional coordinate transformation algorithm, it can quickly and accurately obtain the pitch and azimuth zero-position deviation of the equipment, solving the core problem of initial installation alignment of the equipment. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of error modeling for a common-orientation axial shaft system in an embodiment of the present invention.

[0015] Figure 2 This is a diagram showing the interface for binding the installation error parameters of the inertial measurement unit and the azimuth axis in an embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of the coordinate transformation software tool interface in an embodiment of the present invention.

[0017] Figure 4 This is a schematic diagram illustrating the calibration of the zero-position installation error of the target module of the integrated monitoring equipment in this embodiment of the invention. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Reference Figure 1 This invention provides a method for calibrating the shaft system installation error of an integrated photoelectric monitoring device. The device adopts a common azimuth axis integrated design, and its core sensors include an inertial measurement unit (IMU), a photoelectric image sensor, and a laser rangefinder. It operates through a "pitch-azimuth" dual-axis stabilization platform structure. The theoretical foundation for this calibration is the shaft installation error compensation model, the derivation of which is based on the equipment structure and defines five key coordinate systems: Optical axis coordinate system The origin is located at the center of the photoelectric sensor target surface. The axis coincides with the optical axis; Pitch-rotation coordinate system : with optical axis coordinate system Fixed connection, but there is an installation error angle. ; Pitch axis zero coordinate system :Depend on Around it X Axis rotation The pitch angle is obtained; Azimuth rotation coordinate system : with pitch zero coordinate system Fixed connection, but there is an installation error angle. ; IMU Body Coordinate System : and azimuth coordinate system Fixed connection, but there is an installation error angle. ; The calibration method includes the following steps: Based on the aforementioned shaft system installation error, by establishing the direction cosine matrix transformation relationship between each coordinate system, and comprehensively considering the target vector transfer path under both cases with and without installation error, and through rigorous mathematical derivation and linearization (ignoring higher-order minor quantities), the target vector in the IMU body coordinate system is finally derived. The following height error angle Compensation model for azimuth error angle : ; in, This indicates the pitch axis zero-position deviation; This indicates the zero-position deviation of the azimuth axis; Indicates the pitch rotation axis and azimuth rotation axis at Y Non-perpendicularity of direction; Indicates the orientation rotation axis and the IMU body coordinate system Y The non-perpendicularity of the axis; Indicates the optical axis and the pitch and rotation axis at... Z Non-perpendicularity of direction; H The measured elevation angle of the target vector; Based on the aforementioned compensation model, respectively for , , , and All errors are eliminated or calibrated.

[0020] Specifically, the process of deriving the compensation model includes: When all installation error angles are small, higher-order small quantities are ignored, and the direction cosine matrix transformation relationship between the coordinate systems is established as follows: Optical axis coordinate system To the pitch axis coordinate system The transformation matrix is: ; Pitch-rotation coordinate system To the pitch axis zero coordinate system The transformation matrix is: ; Pitch axis zero coordinate system To the azimuth coordinate system The transformation matrix is: ; Azimuth rotation coordinate system To IMU body coordinate system The transformation matrix is: ; in, It is the identity matrix. , , This represents the cross-product antisymmetric matrix constructed from the angular components of the installation errors of each coordinate system. Representing the coordinate system along X Axis rotation angle; When there is no shaft installation error (ideal case), according to the coordinate system definition: , ; Once the photoelectric tracking device stabilizes its tracking of the target, the target vector... Coinciding with the optical axis, target vector In the optical axis coordinate system The Chinese character is represented as Then the target vector exist The system projection is: ; Then the target vector In the IMU body coordinate system The projection below is: ; Target vector In the IMU body coordinate system The projection below uses the actual elevation angle of the target. H and azimuth A express: ; When shaft installation errors exist (in reality), the target vector In the pitch axis coordinate system The Chinese character is represented as The coordinates are transferred to the IMU body coordinate system via a coordinate system transformation matrix. , to obtain the target vector In the IMU body coordinate system The projection below is: And use the actual measured elevation angle of the target and azimuth express: ; Height error angle introduced by shaft system error and azimuth error angle , and the measured elevation angle of the target and azimuth The relationship between them is: ; Combining the above formulas, we obtain the stellar vector transfer relationships for both cases with and without axis system errors: ; Substituting the direction cosine matrix transformation relationship between the coordinate systems into the above equation, we get: ; Ignoring higher-order minor quantities, the above equation simplifies to:

[0021] Will , Substituting the formulas for altitude and azimuth into the above equation, we get:

[0022] The above equation can be further simplified to obtain:

[0023] in, ; The above equation further yields:

[0024] Expanding the above equation using vector elements, we get:

[0025]

[0026] Considering the IMU body coordinate system Relative to the optical axis (photoelectric sensor target surface) coordinate system With the IMU body azimuth angle remaining constant relative to the optical axis, the target vector in the above formula has the same azimuth angle in the IMU body coordinate system. A It remains a constant value, which can be guaranteed during the design and installation reference. A For small quantities, initial calibration and compensation can be performed by aiming a gyro theodolite at the ground, so that after initial calibration and compensation... Pitch axis height measurement angle Angle of elevation relative to the target H Relationship Then the above formula can be further simplified to: ; make , ; Then we have: ; Among them, parameters This is a constant term, which only relates to each coordinate system. X Axial installation error is related, representing the zero-position deviation in the pitch axis of the reference coordinate system. Parameter The constant term, which is only related to each coordinate system in... Z Axial installation error is related, representing the zero-position deviation in the axial direction of the reference coordinate system. Parameter This indicates the non-perpendicularity between the pitch rotation axis and the azimuth rotation axis; parameter This indicates the non-perpendicularity between the azimuth rotation axis and the IMU body roll axis. (Parameter) This indicates the degree of non-perpendicularity between the optical axis and the pitch / rotation axis.

[0027] Considering that the target elevation angle monitored by the photoelectric integrated monitoring equipment is generally within ±10°, error compensation models can be implemented during the equipment assembly and commissioning phases. , , Separate and eliminate, for , Implement calibration and compensation techniques to ensure that the optoelectronic integrated equipment can obtain the required data when tracking and measuring the target. , To compensate for the measured elevation angle of the target and measured azimuth Thus, the actual elevation angle of the target can be obtained. H and actual azimuth A This is used for accurate calculation of the relative distance to the target in subsequent operations, thereby improving the measurement accuracy of the target by the integrated photoelectric monitoring equipment.

[0028] Specifically, the non-perpendicularity between the pitch rotation axis and the azimuth rotation axis Adjustments were made to eliminate The term error specifically includes: The perpendicularity of the pitch axis to the azimuth axis is mechanically adjusted using either the plumb line method or the autocollimator method (using an autocollimator and a double-sided reflector). During equipment assembly and adjustment, first adjust the pitch axis yaw rate to within 10 arcseconds and the azimuth axis yaw rate to within 5 arcseconds, then adjust the perpendicularity... The time is controlled within 20 arcseconds, ensuring that the device monitors the target elevation angle. H Within ±10°, The value of the item is less than 3.5 arcseconds. Since the perpendicularity of the pitch and azimuth axes is relatively stable after adjustment, it is less affected by environmental stress factors. Therefore, the error... It can be ignored.

[0029] Specifically, after completing the previous step, the non-perpendicularity between the optical axis and the pitch rotation axis can be checked. Adjustments were made to eliminate The term error specifically includes: The perpendicularity of the optical axis to the pitch axis is mechanically adjusted using the "positive and negative mirror method"; the non-perpendicularity is then corrected. The time is controlled within 15 arcseconds, ensuring that the device monitors the target elevation angle. H Within ±10°, The value of the item is less than 16 arcseconds, which is an acceptablely small amount and can be ignored.

[0030] Specifically, the non-perpendicularity between the orientation rotation axis and the IMU body coordinate system Calibration and digital compensation are performed to eliminate The error in the installation of the azimuth rotation axis coordinate system and the IMU body coordinate system. , After the equipment is assembled and debugged, measurement and digital compensation can be performed using the azimuth axis modulation digital calibration method. The compensation principle is based on the fact that, under static conditions, the single-axis rotary modulation IMU outputs the carrier attitude step change error before and after rotating 180° along the azimuth axis. , Installation error between IMU body and orientation rotation axis , The following relationship must be satisfied: , ; Therefore, under static conditions, based on the carrier attitude error obtained by IMU demodulation before and after the turntable rotates 180°, the installation error angle between the azimuth axis coordinate system and the IMU body coordinate system is calculated. , The IMU output attitude is compensated based on the back-calculated installation error, so that the IMU output carrier attitude step jump error before and after the turntable rotates 180° is reduced. , Therefore, after compensation , .

[0031] The specific compensation steps include: After the equipment is assembled and debugged, place the equipment on the platform (a vibration-free ground or marble platform) and start the equipment to complete the alignment of the inertial measurement unit (IMU); After the inertial measurement unit (IMU) is aligned, record the carrier's calculated output. X and Y Orientation and attitude values ​​(IMU output roll and pitch values); The control device rotates its azimuth axis 180°. Once the azimuth axis has reached its position and stabilized, the carrier data calculated by the inertial measurement unit is recorded. X and Y Orientation and attitude values; The IMU outputs the vehicle roll angle before and after the azimuth axis rotation. and pitch angle ; Calculate the step jump error of the carrier attitude before and after azimuth axis rotation and ; According to the formula: , Calculate the installation error angle ; The calculated The value is used as an error compensation parameter and is bound to the inertial measurement unit to compensate for the non-orthogonality error between the IMU body and the azimuth axis, such as... Figure 2 As shown.

[0032] Iteratively execute the above steps until the attitude step jump error is reached. and Approximately zero, thus achieving This allows the equipment to monitor the target elevation angle. H Within ±10° The value of the term is negligible.

[0033] Specifically, regarding the pitch axis zero-position deviation and azimuth axis zero position deviation Calibration and compensation require a portable real-time satellite positioning (RTK) system (including a base station and a rover with built-in radios, providing a positioning error better than 0.03 meters) and a portable target plate (the target plate should have a white or light gray diffuse reflective material on the front, and its size should be no less than 600mm × 600mm; the center position of the target plate should be marked with a "+" sub-line). , The calibration.

[0034] The specific compensation steps include: Select two suitable locations, 150 to 180 meters apart, to place the integrated monitoring equipment and the target module respectively; An RTK base station was set up near the integrated photoelectric monitoring equipment, and an RTK rover station was used to accurately measure the first geodetic coordinates of the center point (base point, installation position of the pitch axis photoelectric image sensor) of the integrated photoelectric monitoring equipment. And the second geodetic coordinates of the center point of the crosshairs of the target module. ; Based on the WGS-84 Earth ellipsoid model, the first and second geodetic coordinates are converted into spatial rectangular coordinates, and the azimuth angle of the vector from the center point of the photoelectric integrated monitoring equipment to the target center in a spherical coordinate system with the equipment center point as the origin is further calculated. Horizontal pitch angle , X Axis (North) Distance , Y Axis (Eastward) Distance , Z Axial (Ground) Distance And the vector; such as Figure 3 As shown, the values ​​calculated by coordinate software can be used as theoretical true values.

[0035] The integrated monitoring equipment is activated, and it is controlled to aim at and track the center of the crosshairs of the target module. The measured azimuth angle of the vector from the center point of the integrated monitoring equipment to the center of the target in the northeast coordinate system is obtained. and measured pitch angle as well as X North axis distance , Y Eastward distance , Z Axial distance value Then the zero-position deviations of the equipment's azimuth and pitch axes can be calculated: , ; Click the parameter dialog box inside the device display and control interface, and enter the calculated value. The error is input into the shaft system error calibration software module of the photoelectric integrated monitoring equipment to complete the software compensation for zero-position deviation, such as... Figure 4 As shown.

[0036] Furthermore, the geodetic coordinates are converted to spatial rectangular coordinates and the azimuth angle in the spherical coordinate system is calculated. and pitch angle Based on the geodetic coordinates (latitude, longitude, and altitude) of both the observation equipment station and the observed target, the spherical coordinates (azimuth, elevation, and distance) of the target relative to the station are calculated. This calculation process is actually a coordinate transformation between different coordinate systems. First, the following three coordinate systems need to be defined.

[0037] 1) Spatial geodetic coordinate system – describing spatial location using latitude, longitude, and altitude; 2) Spatial rectangular coordinate system – the origin is located at the center of the Earth's reference ellipsoid. X The axis points to the intersection of the initial meridian plane and the equator. Y The axis points to the intersection of the 90° east longitude line and the equator. Z The axis points to the North Pole; 3) Station Cartesian Coordinate System – with the station as the origin, XY The plane is parallel to the horizontal plane of the area. X The axis points due north. Y The axis points due east. Z The axis points to the ground; 4) Station spherical coordinate system – with the station as the origin, the azimuth angle along… X The positive axis is 0°, clockwise is positive, and the range is [0, 360)°. The pitch angle is defined as follows: XY The plane is 0°, the upward is positive, the range is [-90, 90]°, and the distance is the straight-line length from the target to the station.

[0038] Before performing the calculation, first determine a set of fundamental constants for the Earth's reference ellipsoid—the major axis radius. a Flatness f First eccentricity e For the WGS-84 reference ellipsoid, the specific parameters are shown in Table 1 below: Table 1 WGS-84 Ellipsoid Parameters

[0039] Based on the following two sets of known conditions: Spatial geodetic coordinates of the site: latitude ,longitude ,high (rice); Spatial geodetic coordinates of the target: latitude ,longitude ,high (rice); The process of calculating the horizontal angle coordinates of the target station includes the following steps: Spatial geodetic coordinates of the equipment site Convert to spatial rectangular coordinates : ; in, ; The spatial geodetic coordinates of the target Convert to spatial rectangular coordinates : ; in, ; The spatial rectangular coordinates of the target Convert to coordinates in the device site Cartesian coordinate system : ; in, , , ; The coordinates of the target in the Cartesian coordinate system of the device site Coordinates converted to the device site spherical coordinate system : Among them, azimuth angle The calculation formula is as follows: ; in, [0°, 360°); Pitch angle The calculation formula is as follows: ; in, , [-90°, 90°]; The formula for calculating distance is: .

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for calibrating shaft installation errors in photoelectric integrated monitoring equipment, characterized in that, The device adopts a common-axis integrated design, including an optical axis coordinate system. Pitch-rotation coordinate system Pitch axis zero coordinate system Azimuth rotation coordinate system and IMU body coordinate system The shaft system installation error includes: Optical axis coordinate system With pitch axis coordinate system Installation error angle between Pitch axis zero coordinate system With azimuth axis coordinate system Installation error angle between and the azimuth rotation coordinate system With IMU body coordinate system Installation error angle between ; The calibration method includes the following steps: Based on the aforementioned shaft system installation error, the target vector in the IMU body coordinate system is derived. The following height error angle Compensation model for azimuth error angle : ； in, This indicates the pitch axis zero-position deviation; This indicates the zero-position deviation of the azimuth axis; Indicates the pitch rotation axis and azimuth rotation axis at Y Non-perpendicularity of direction; Indicates the orientation rotation axis and the IMU body coordinate system Y The non-perpendicularity of the axis; Indicates the optical axis and the pitch and rotation axis at... Z Non-perpendicularity of direction; H The measured elevation angle of the target vector; Based on the aforementioned compensation model, respectively for , , , and All errors are eliminated or calibrated.

2. The method for calibrating shaft installation errors in a photoelectric integrated monitoring device as described in claim 1, characterized in that, The process of deriving the compensation model includes: Establish the direction cosine matrix transformation relationship between the coordinate systems as follows: Optical axis coordinate system To the pitch axis coordinate system The transformation matrix is: ； Pitch-rotation coordinate system To the pitch axis zero coordinate system The transformation matrix is: ； Pitch axis zero coordinate system To the azimuth coordinate system The transformation matrix is: ； Azimuth rotation coordinate system To IMU body coordinate system The transformation matrix is: ； in, It is the identity matrix. , , This represents the cross-product antisymmetric matrix constructed from the angular components of the installation errors of each coordinate system. Representing the coordinate system along X Axis rotation angle; When there is no shaft installation error, the target vector In the optical axis coordinate system The Chinese character is represented as The coordinates are transferred to the IMU body coordinate system via a coordinate system transformation matrix. , to obtain the target vector In the IMU body coordinate system The projection below is: and use the actual elevation angle of the target H and azimuth A express: ； When shaft installation errors exist, the target vector In the pitch axis coordinate system The Chinese character is represented as The coordinates are transferred to the IMU body coordinate system via a coordinate system transformation matrix. , to obtain the target vector In the IMU body coordinate system The projection below is: And use the actual measured elevation angle of the target and azimuth express: ； Height error angle introduced by shaft system error and azimuth error angle , and the measured elevation angle of the target and azimuth The relationship between them is: ； By combining the above formulas, the target vector is finally obtained. In the IMU body coordinate system The following height error angle Compensation model for azimuth error angle .

3. The method for calibrating shaft installation errors in a photoelectric integrated monitoring device as described in claim 1, characterized in that, The non-perpendicularity of the pitch rotation axis and the azimuth rotation axis Adjustments were made to eliminate The term error specifically includes: The perpendicularity of the pitch axis and azimuth axis is mechanically adjusted using the plumb line method or autocollimator method. During equipment assembly and adjustment, first adjust the pitch axis yaw rate to within 10 arcseconds and the azimuth axis yaw rate to within 5 arcseconds, then adjust the perpendicularity... The time is controlled within 20 arcseconds, ensuring that the device monitors the target elevation angle. H Within ±10°, The value of the term is less than 3.5 arcseconds, and therefore is ignored in error compensation.

4. The method for calibrating shaft installation errors in a photoelectric integrated monitoring device as described in claim 1, characterized in that, The non-perpendicularity of the optical axis to the pitch and rotation axis Adjustments were made to eliminate The term error specifically includes: The perpendicularity of the optical axis to the pitch axis is mechanically adjusted using the upright and reverse mirror method; the non-perpendicularity is then corrected. The time is controlled within 15 arcseconds, ensuring that the device monitors the target elevation angle. H Within ±10°, The value of the term is less than 16 arcseconds, and therefore it is ignored in error compensation.

5. The method for calibrating shaft system installation errors in a photoelectric integrated monitoring device as described in claim 1, characterized in that, The non-perpendicularity of the orientation rotation axis to the IMU body coordinate system Calibration and digital compensation are performed to eliminate The term error specifically includes: After placing the device still on the platform and completing IMU alignment, control the device to rotate its orientation axis 180°. The IMU-calculated roll angles of the carrier were obtained before and after the azimuth axis rotation. and pitch angle ; Calculate the step jump error of the carrier attitude before and after azimuth axis rotation and ; According to the formula: , Calculate the installation error angle ; The calculated The value is used as an error compensation parameter and is bound to the inertial measurement unit to compensate for the non-orthogonality error between the IMU body and the azimuth axis; Iteratively execute the above steps until the attitude step jump error is reached. and Approximately zero, thus achieving This allows the equipment to monitor the target elevation angle. H Within ±10° The value of the term is negligible.

6. The method for calibrating shaft installation errors in a photoelectric integrated monitoring device as described in claim 1, characterized in that, For the pitch axis zero position deviation and azimuth axis zero position deviation Calibration and compensation are performed, specifically including: Photoelectric integrated monitoring equipment and target modules are set at two different locations. The front of the target module is provided with a crosshair for marking the center. An RTK base station was set up near the photoelectric integrated monitoring equipment, and an RTK rover station was used to accurately measure the first geodetic coordinates of the center point of the photoelectric integrated monitoring equipment. And the second geodetic coordinates of the center point of the crosshairs of the target module. ; Based on the WGS-84 Earth ellipsoid model, the first and second geodetic coordinates are converted into spatial rectangular coordinates, and the azimuth angle of the vector from the center point of the photoelectric integrated monitoring equipment to the target center in a spherical coordinate system with the equipment center point as the origin is further calculated. and horizontal pitch angle ; The photoelectric integrated monitoring equipment is controlled to aim at and track the center of the crosshairs of the target module, and the measured azimuth angle of the vector from the center point of the photoelectric integrated monitoring equipment to the center of the target in the northeast coordinate system is obtained. and measured pitch angle ; Calculate the zero-point deviation: , ; The calculated The error is input into the shaft system error calibration software module of the photoelectric integrated monitoring equipment to complete the software compensation for zero-position deviation.

7. The method for calibrating shaft installation errors in a photoelectric integrated monitoring device as described in claim 6, characterized in that, Convert geodetic coordinates to spatial rectangular coordinates and calculate the azimuth angle in spherical coordinates. and pitch angle The methods include: Calculate the radii of curvature of the geodesic zone and the target point based on the WGS-84 ellipsoid parameters: ； in, a The major radius of the ellipsoid is e The first eccentricity; Spatial geodetic coordinates of the equipment site Convert to spatial rectangular coordinates : ； in, ; The spatial geodetic coordinates of the target Convert to spatial rectangular coordinates : ； in, ; The spatial rectangular coordinates of the target Convert to coordinates in the device site Cartesian coordinate system : ； in, , , ; The coordinates of the target in the Cartesian coordinate system of the device site Coordinates converted to the device site spherical coordinate system : Among them, azimuth angle The calculation formula is as follows: ； Pitch angle The calculation formula is as follows: ； in, ; The formula for calculating distance is: .

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