The Aiming Technology Research In Optical Non-contact 3-D Measure Instrument

The geometrical parameter measurement becomes an important part of metrology. As the basement of the measurement, the length measurement has caught people's attention and become research content from one dimensional, two dimensional(2-D), three dimensional(3-D)to high-dimensional space with the new measurement theory present and the new measurement technologies applied. The measurement technology based on optics is a non-contact, since scanning, high-precision and fast access profile measuring method. And it has been a promising technique in all fields of the industrial measurement and detection.Non-contact 3-D measure instrument is consisted of a CCD picture sensor, position sensitive detector, an optical grating sensor, an optical image formation system, a data capture system, laser transmitter and an optical non-contacted three-dimensional measurement consisting of computer and interrelated mechanical structure. It is well known that the performance of a measuring instrument is determined by its edge aiming precision. Making use of various photoelectric sensors and the characteristic of optics measurement, such as non-contact, whole-filed measuring and high precision, this paper designs a non-contact optical probe. The detected device divides three dimensional measurement into plane two-dimensional measurement and one-dimensional measurement of Z direction. Plane two-dimensional measurement make mainly use of CCD imaging technology, image processing technology, sub-pixel technology and other technology to achieve automatic aiming, automatic calculation of the edge on measured object. The paper detailed introduces the idiographic measure principle of the measuring system, designs the relevant mechanism and software system. In the part of theory, some image processing and several common computational algorithms of the sub-pixel edge measurement were discussed. PSD is characterized by high frequency responsibility, simple interface circuit, fast data collection and so on. On Z direction one-dimensional measurement, the paper design a non-contact laser probe. Like plane two-dimensional measurement, the device aim the measured object with laser non-contact probe in one-dimensional measurement of Z direction. In theory, the relevant knowledge about PSD is introduced firstly, in practice the relevant design of the hardware circuit and mechanical structure are introduced. At last , the paper discusses the reason causing the error with the measuring results. The analysis of the measuring results indicates the correctness of the measuring method.