Optical Triangulation Method To Measure The Small Angle

Angle measurement is one of the most important parts of metrology, which is used widely in industrial production and the scientific research domain. With the science and technology rapid development, the high precision of angle measurement is requested in the precise processing, the aerospace, the military affairs and the communication and so on, especially small angle measurement. People pay more attention to the photoelectric method, which has the non- contact, the high accuracy and the high sensitivity strongpoint, especially with the laser device development and the precision sensor appearance, the photoelectric method' s measuring accuracy is unceasingly enhancing, and the application domain is more widespreading. At present stage because used advanced survey method and metering equipment, the survey accuracy and precision has been achieved a high level. But the instrument of traditional small angle measurement like laser interferometer, photoelectric collimator and so on, can hardly be used as angle sensor in industrial production and high accuracy on-line measurement because they are bulky, complicated, expensive, and demanding strict work environment.At present, optical triangulation in measurement of displacement, thickness and three-dimension shape etc had achieved a high precision, so it has high usability and research value. Based on this, research on uses optical triangulation in the small angle on-line survey was carried out in this thesis. The principle of optical triangulation was analyzed and established the survey model of the small angle measurement using this method firstly, then constructed the simple experiment measurement system use the colour CCD camera as PSD, whereafter compared some kind of filters and interpolation methods, choose the Median filter and the Gray Barycenter method process the facula of the CCD camera gathered, realized sub-pixel localization of the facula center, thus realized high accuracy on-line measurement of object' s turn angle.Finally, the each kind of factor that influent the system and measuring error of this experimental system have been analyzed in detail, principle analysis and experiment result indicate that the non-contact small angle measurement using optical triangulation is feasible.