Research And Implementation Of Roll Angle Full-circle Measurement System Based On Moiré Fringe

Roll angle refers to the angle change around the axis of the device itself,which is a dimension of three-dimensional angle displacement,and widely exists in large survey ships,and precision measurement and control system,etc.At present,the measurement technology for yaw and pitch has been relatively mature.However,due to the characteristics that the roll angle whose axis coincides with the motion direction of the measured object,the measurement is difficult and the measurement range is relatively limited.The transfer and measurement of pose reference has important application value,and the research of roll angle measurement at any position is of great significance for the development of photoelectric measurement technology.In order to realize the roll measurement at any angle within the range of 360°,this paper proposes a full-circle measurement method for the roll angle based on the moiré fringe principle,and carries out simulation analysis and experimental verification for the mathematical model of each part of the scheme.Specifically,the main research work and innovative achievements of this paper are as follows:1.The principle of moiré fringe roll measurement is analyzed,the relationship between the measurement range of roll angle and the resolution is deduced,the nonlinear model between the roll angle and the resolution is established,and the best measurement area that can be realized based on the current detector is obtained.2.A servo-controlled full-circle measurement scheme for the roll angle based on moiré fringe is proposed.The absolute zero position of the roll angle is calibrated by the shaft encoder to achieve high-precision measurement of any angle within the range of 360° roll angle,and the measurement accuracy is better than 5.6?.3.The three-dimensional coupling analysis model between yaw,pitch and roll angle is established.By means of polynomial fitting compensation method,the influence of angle coupling on the measurement accuracy of roll angle is basically eliminated,and the accuracy of roll angle is guaranteed in engineering application.4.A self-adaptive extraction and correction algorithm for moiré fringe centerline is proposed,which improves the accuracy of moiré fringe centerline extraction and effectively reduces the influence of air heat flow disturbance on the accuracy of roll angle measurement.The roll angle measurement is of great significance for ensuring the stability of large-scale precision measurement and control systems.By taking the characteristics of high sensitivity and displacement amplification of moiré fringe,and aiming at the problem of limited measuring range,a novel full-circle roll measurement scheme is proposed,and the design method of system prototype is described in detail,which lays a solid engineering foundation for the application and promotion of the full-circle roll measurement system.