Study Of Collimation Measurement Accuracy For The Large-Field Photoelectric Autocollimator

The auto-collimating technique utilizes the principle of the optimal auto-collimation imaging for either directly measuring the small angle with high precision or changing a large angle into a small angle. Based on the technique, the autocollimator is developed and widely used as a measuring instrument. According to the different modes in outputting measure results, the autocollimator is categorized into two types, via, the optical-autocollimator and the photoelectric autocollimator. Due to the high performance compared with the optical-autocollimator, the photoelectric autocollimator has been used in many practical measurement problems, such as the measurement of small angles, the adjustment of high precision angles, the straightness of air-tracts, the flatness of precision platforms, the position uncertainty of turntables and so on. However, the existing photoelectric autocollimators own small observation range and low measurement precision, which will escape from the society's development. Thus a large-field observation range and high measurement precision are key research topics of the advanced autocollimator and also meet the current society's requirement.The thesis focuses on improving observation range and measurement precision of a large-field photoelectric autocollimator. The main contributions of the thesis are summarized as follows:Firstly, based on analyzing the optical working principles of the existing autocollimators from different countries, a new optical structure which can enlarge the measurement range is developed and the main optical parameters are determined according the design goals.Secondly, to guarantee the measurement accuracy and stability of the large-field photoelectric autocollimator, some key techniques including the illumination system of the light source, the resolution of the photo-detector and the measurement algorithms are explored.Finally, the installment and debugging techniques affecting the measurement accuracy are also studied by conducting the experiment and the error analysis. The final experiment results verity their affectness.