The Calibration Method With The Minimum Parameter For Arbitrary Attitude Camera Of Coordinate Positioning Monitoring System In The Field

In the field of complex terrain environment,aiming at the field coordinate measurement of multiple monitoring areas of a shooting range,a calibrating method with the least parameters based on binocular stereoscopic vision was proposed,which can calibrate the camera's three attitude angles and focal lengths simultaneously by only two calibration points.Combining the traditional calibration method with the optimization algorithm,the camera calibration equation is iteratively solved,and the required calibration parameters are minimized with the assurance of accuracy,so that the calibration method only needs to monitor any two calibration points in the region.According to the GPS coordinates of the calibration point and the image coordinates on the camera,the three attitude angles and focal distances of the camera can be quickly calculated.Combined with the application background,the selection of calibration points is no longer limited by the layout rules by establishing a unified world coordinate system,so that the calibration process is greatly simplified.The field experiment verified the accuracy of the measurement method.The results show that the relative error was better than 0.59% in the circular monitoring area with a diameter of 200 m.The calibration method does not require high-precision targets and overcomes the influence of the target placement on the measurement accuracy of the coordinate positioning.It has the advantages of simple operation,wide application range and high precision,and is suitable for the field space coordinate measurement in the longdistance and complex terrain environment and has practical application value.The main contents of this paper include:1.The development of binocular stereoscopic coordinate positioning and camera calibration at home and abroad.The advantages and disadvantages of each calibration method are analyzed,and the content of this paper in the application background is put forward.2.The system configuration and measurement process are systematically introduced.A binocular stereo vision measurement model of the system is constructed.The model is simplified with the practical application.The principle of spatial coordinate measurement is analyzed.3.This paper focuses on the calibration method with the least parameter in the context of system application.In this paper,the camera calibration model of the system is built.A unified world coordinate system is established according to the application background.The optimization algorithm for solving the system calibration equation is studied,and the selection method of the initial value for the optimization algorithm is elaborated.The method reduces the calibration equations required,so that the calibration method can calibrate four unknown parameters with a minimum of known parameters.The calibration method is more flexible and has a wider scope of application.4.By establishing the simulation model of the system using MATLAB,the influence of the pixel coordinate extraction error,the coordinate error of the main point,the calibration point layout and the camera layout on the measurement error are analyzed,and the optimization rules of the camera layout is obtained.5.The field coordinate positioning monitoring system software is described combined with the software interface.This paper described in detail the software interface,the operation of various functional modules and the design method of software data interaction and management.6.Experiments are conducted in the field to verify the calibration methods studied in this paper.The analysis of the experimental data shows that the proposed method can accomplish the calibration tasks required by the system well and meet the precision requirements of the system.