Research On The Three Dimensional Measurement Method Of Micro-table Position And Pose Based On Machine Vision

With the micro/nano technology rapid development, MEMS has been widely used in the actual production process. Because the MEMS has the structure size to be small, the loading abilities to be weak, cannot install the sensors to measure the geometrical quantity in the measuring process, only to use non-contact measurement. Since the 1990s, the computer vision measurement technology has become the research hot spot in the field of non-contact measurement, commonly used measuring technique mainly have the monocular vision,the binocular vision and many item of visual measurement. Based on the machine vision technology, can gain the three-dimensional information of the detected objects, this paper proposed that the measurement method of micro-table position and pose, this method is based on the principles of monocular vision measurement, combined with the transformation between the coordinate systems, can be calculated the micro-table position and pose in three-dimensional space.The research objects of micro platform is a rectangular platform with regular shape in this paper, according to the geometrical properties of rectangular, this paper proposes a new method that the camera calibration based on six points. Select the six peaks as mark from micro platform, based on the theory of common camera calibration, described in detail the calibration of six principles and the specific calibration algorithm derivation; based on the principles of monocular vision measurement, the four corners and the edge of the rectangular are used as the feature elements, combined with the transformation between the coordinate systems, established the mapping model between world coordinate system,camera coordinate system and image coordinate system,can get the micro-table position and pose in three-dimensional space. According to the principle of pinhole imaging, can obtain the rule that length of the edge changes with the distance change between edge and focal plane, then achieved the measurement distance of micro-table; Proposed for the measurement of monocular vision platform for the three micro-movement measurement, building the experimental platform based on the principle of three coordinate measuring machine, extracting the coordinate of the feature points, getting the world coordinate of the feature points based on the principles of monocular vision measurement, Through the contrast experiment results show that the measurement method is feasible.According to the above research results, this paper make the use of machine vision to research the micro-table position and pose, and get the method for solving the position and pose based on the feature elements. This method can not only realize the fast tracking measurement of micro platform, but also can greatly reduce the computational complexity.