Research On The Key Technologies Of Laser Goniometry System Based On The Array CCD

In order to achieve the function of automatic guide, it is necessary to have a real-time measure on the data of attitude angles (pitching angle, roll angle and horizontal angle) of Tunnel Boring Machine (TBM). Pitching angle and roll angle can be surveyed by the inclination sensor; while the accurate measurement of horizontal angle is still a tough work. To have a precise data of the horizontal angle, a new method, laser goniometry based on the array CCD was brought up in this paper. The main content is as following:1. The principle of measurement of the horizontal angle is to be researched. Based on the principle of lens imaging, when the angle between the incident laser bean and the lens optical axis changes, the location of the image spot on the array CCD changes accordingly. Therefore, the angle can be calculated by the coordinate of the spot.2. The principle and method of the edge detection is to be demonstrated to realize an accurate location of spot. In order to make a sophisticated detection, a method of sub-pixels edge detection based on Zernike moments is to be chosen. Base on the analysis of its principle, the method of how to determine the key parameters is to be researched.3. Based on the fact that the spot is nearly a circle after it is focusing, the method of Hough transform and the method of least square circle are compared. The result indicated that the method of the least square circle realized by an emluator could make a more accurate calculation of the coordinate of the spot.4. An simulation experiment is to be designed to realize the median filtering,sub-pixel edge detection and least square circle location. The effects of the parameters on the accuracy of location was analysed.