A photoelectric system azimuth-elevation calibration method based on observing multi-point targets

Abstract

The application discloses a photoelectric system azimuth and elevation calibration method based on observation of multiple point targets. The method can be applied to the fields of unmanned aerial vehicle low-altitude monitoring and security control, etc. The method comprises the following steps: setting a calibration point; collecting calibration point parameters and obtaining photoelectric correction parameters; and guiding and controlling the photoelectric system according to the longitude and latitude of the target and the longitude and latitude of the photoelectric system by using the calibration parameters. The method can effectively calibrate the azimuth and elevation errors caused by the non-horizontal installation surface of the photoelectric system base, and the operation method is simple and clear. The calibration result can be used for control and correction of any azimuth and elevation of the photoelectric system.

Description

Technical Field

[0001] This invention discloses a method for azimuth and elevation calibration of an optoelectronic system based on observing multiple targets. This invention can be applied to fields such as low-altitude surveillance and security control using unmanned aerial vehicles (UAVs). Background Technology

[0002] Optical target tracking offers high accuracy and data rate, and can acquire target image information. Applications using target-guided optoelectronic systems to capture targets (i.e., using the absolute position of the target detected by other methods, along with the optoelectronic installation position and attitude, to calculate control parameters for the optoelectronic system, thereby controlling its rotation and capturing the target) are common. However, in actual deployment, deviations in the optoelectronic azimuth and elevation angles from the target's true azimuth and elevation zero points, installation errors, and ground settlement causing the optoelectronic base to be less than perfectly horizontal result in discrepancies between the optoelectronic azimuth and elevation angles and the target's true azimuth and elevation angles. This can lead to situations where the target cannot enter the optical field despite the optoelectronic system being guided. Simply observing a single target and calibrating the optoelectronic azimuth and elevation zero-point errors cannot eliminate the azimuth and elevation errors caused by the tilt of the optoelectronic installation plane. Therefore, considering the above factors, to ensure the target-guided optoelectronic system can more accurately capture targets when the installation plane is tilted, a more systematic and accurate calibration of the optoelectronic system's azimuth and elevation angles is needed. Summary of the Invention

[0003] This invention provides a method for azimuth and elevation calibration of a photoelectric system based on observation of multiple targets. This method addresses the issue of the photoelectric base not being able to be adjusted to be completely horizontal. It calibrates the azimuth and elevation of the photoelectric system, eliminates deviations between the azimuth and elevation zero points and the coordinate azimuth and elevation zero points, installation errors, and errors caused by ground settlement preventing the photoelectric base from being completely horizontal. This enables more precise guidance and control of the photoelectric system.

[0004] The technical solution adopted in this invention is as follows:

[0005] A method for azimuth and elevation calibration of an optoelectronic system based on observing multiple targets includes the following steps:

[0006] (1) Set the calibration point. The specific process is as follows:

[0007] Using the photoelectric source as the origin, at least three calibration points are obtained clockwise at a set distance and in line with the photoelectric source. The clockwise angle between the first calibration point and the last calibration point should be greater than 180°.

[0008] (2) Obtaining photoelectric calibration parameters, the specific process is as follows:

[0009] (201) Collect calibration point parameters for each calibration point in sequence: collect the latitude, longitude and altitude of the calibration point respectively, magnify the optical television field to the set magnification, rotate the photoelectric device to point the center of the field of view to the calibration point, and record the azimuth and elevation angle of the photoelectric observation calibration point at this time;

[0010] (202) Calculation of photoelectric calibration parameters: Based on the latitude and longitude of the calibration point and the azimuth and elevation angles of the photoelectric observation calibration point, a position deviation estimation method for photoelectric sensing devices based on particle swarm optimization is adopted to calculate the photoelectric calibration parameters, namely the azimuth, roll angle and dive angle of the plane where the photoelectric device is located.

[0011] (3) The photoelectric calibration parameters are used to guide and control the photoelectric system. The specific process is as follows:

[0012] (301) Obtain the azimuth and elevation angles of the target relative to the photoelectric sensor: Calculate the azimuth and elevation angles of the target relative to the photoelectric sensor based on the latitude and longitude of the target and the latitude and longitude of the photoelectric sensor.

[0013] (302) Calculate the control parameters: Based on the azimuth and elevation angles of the target relative to the photoelectric sensor and the photoelectric calibration parameters calculated in step (2), a position deviation estimation method for photoelectric sensing devices based on particle swarm optimization is adopted to calculate the azimuth and elevation angles of the photoelectric observation target, thereby deriving the control parameters for guiding the photoelectric sensor.

[0014] The advantages of this invention compared to the prior art are as follows:

[0015] (1) This invention can effectively calibrate the azimuth and pitch angle errors caused by the non-horizontal mounting surface of the photoelectric system base. The operation method is simple and clear.

[0016] (2) The calibration results of this invention can be used for the control and correction of any orientation and pitch angle of the optoelectronic system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of setting calibration points according to an embodiment of the present invention.

[0018] Figure 2 This is a flowchart of the photoelectric calibration and control parameter calculation in an embodiment of the present invention. Detailed Implementation

[0019] The following is in conjunction with the appendix Figure 1-2 The present invention will be further described below.

[0020] A method for azimuth and elevation calibration of an optoelectronic system based on observing multiple targets, such as... Figure 2 As shown, it specifically includes the following steps:

[0021] (1) Set the calibration point. The specific process is as follows:

[0022] like Figure 1 As shown, with the photoelectric sensor as the center O, N (N≥3) points A, B, C...N are selected clockwise at a suitable distance from the center and in line with the photoelectric sensor as calibration points, where ∠AON should be greater than 180°.

[0023] (2) Obtaining photoelectric calibration parameters, the specific process is as follows:

[0024] (201) Collect calibration point parameters: Obtain the latitude, longitude and altitude of calibration A, B, C...N and convert them into the northeast celestial coordinate matrix m1 relative to the center O of the photoelectric circle. Magnify the photoelectric field to a suitable magnification, and then rotate the photoelectric field to point the center of the field of view to calibration points A, B, C...N respectively. Record the azimuth and elevation angle matrix m2 of the photoelectric observation calibration points A, B, C...N at this time.

[0025] (202) Calculation of photoelectric calibration parameters: Based on the parameter matrices m1 and m2 of calibration points A, B, C...N, a position deviation estimation method for photoelectric sensing devices based on particle swarm optimization is used to calculate the photoelectric calibration parameters, i.e., the azimuth angle θ of the plane where the photoelectric sensor is located. x Pitch angle θ y With roll angle θ z .

[0026] (3) The photoelectric calibration parameters are used to guide and control the photoelectric system. The specific process is as follows:

[0027] (301) Obtain the azimuth and elevation angles of the target relative to the photoelectric sensor: Based on the latitude and longitude of the target {lon1,lat1,alt1} and the latitude and longitude of the photoelectric sensor {lon2,lat2,alt2}, calculate the azimuth angle α1 and elevation angle β1 of the target relative to the photoelectric sensor.

[0028] (302) Obtain accurate control parameters: Based on the azimuth angle α1 and elevation angle β1 of the target relative to the photoelectric sensor and the photoelectric calibration parameters calculated in step (2), that is, the azimuth angle θ of the plane where the photoelectric sensor is located. x Pitch angle θ y With roll angle θ z A pose deviation estimation method for photoelectric sensing devices based on particle swarm optimization is adopted to calculate the azimuth angle α and elevation angle β of the photoelectric observation target, thereby deriving the control parameters for guiding the photoelectric device.

Claims

1. A method for azimuth and elevation calibration of an optoelectronic system based on observing multiple targets, characterized in that, Includes the following steps: (1) Set the calibration point. The specific process is as follows: Using the photoelectric source as the origin, at least three calibration points are obtained clockwise at a set distance and in line with the photoelectric source. The clockwise angle between the first calibration point and the last calibration point should be greater than 180°. (2) Obtaining photoelectric calibration parameters, the specific process is as follows: (201) Collect calibration point parameters for each calibration point in sequence: collect the latitude, longitude and altitude of the calibration point respectively, magnify the optical television field to the set magnification, rotate the photoelectric device to point the center of the field of view to the calibration point, and record the azimuth and elevation angle of the photoelectric observation calibration point at this time; (202) Calculation of photoelectric calibration parameters: Based on the latitude and longitude of the calibration point and the azimuth and elevation angles of the photoelectric observation calibration point, a position deviation estimation method for photoelectric sensing devices based on particle swarm optimization is adopted to calculate the photoelectric calibration parameters, namely the azimuth, roll angle and dive angle of the plane where the photoelectric device is located. (3) The photoelectric calibration parameters are used to guide and control the photoelectric system. The specific process is as follows: (301) Obtain the azimuth and elevation angles of the target relative to the photoelectric sensor: Calculate the azimuth and elevation angles of the target relative to the photoelectric sensor based on the latitude and longitude of the target and the latitude and longitude of the photoelectric sensor. (302) Calculate the control parameters: Based on the azimuth and elevation angles of the target relative to the photoelectric sensor and the photoelectric calibration parameters calculated in step (2), a position deviation estimation method for photoelectric sensing devices based on particle swarm optimization is adopted to calculate the azimuth and elevation angles of the photoelectric observation target, thereby deriving the control parameters for guiding the photoelectric sensor.

Images