Research On High Precision Laser-based Triangulation Detector Used In 3-D Measurement

More and more actual information is needed as modern society steps into information age. However, the traditional information such as texts and audio files can not satisfy people any more. The information of images and graphs is becoming important, in which 3-D images are included in the nature of things. All kinds of related technologies, including acquiring, recovery and rebuilding of 3-D image information, have developed along this trend.In this paper, laser-based triangulation in 3-D profile measurement areas is researched in detail. The principle of laser-based triangulation is introduced first, then Scheimpflug condition which can make sure ideal imaging is derived by mathematical computation. High precision scheme is proposed based on high performance of laser-based triangulation.The hardware structure includes a laser-based triangulation detector and its signal processing circuit. High precision and high quality ICs and lens components are chose to make sure high measurement precision. This system accompanying with a CMM (coordinate measurement machine) can reach high precision measurement.The software parts accomplish data collecting and basic information processing. The profile information of measured objects can be collected into MCU (Microcontroller Unit). After simple processing, the signals bringing location information are sent to computer to be further processed.Experiments are made to validate the efficiency of this detector system. The results of data processing show that there are many factors that affect measurement precision of the detector, and the most important factor is the resolving power of photoelectric detector and optical system. So better performance will be got if photoelectric detector and optical system with higher precision are used.At last, the development trend of high precision 3-D measurement based on laser-based triangulation is prospected.