The Research On 3D Coordiante Laser Measuring System Basing On Target Collaboration

In recent years, the 3D coordinate laser measuring technique basing on target collaboration gradually shows its unique advantage. This technique, being widely applied in many fields such as 3D measurement of parts, measurement of geometrical parameter, automobile repair, assemble of car, and so on, has become an important measuring method to improve the productive efficiency and to ensure the quality of product. This thesis focuses on the research of 3D coordinate laser measuring system basing on target collaboration by carrying through a comprehensive research on measuring principle and relevant mathematical module. The designed measuring system applies four laser-beams to eliminate the influence of target position and to better identify the target. Many technologies are used to achieve real-time 3D coordinate measurement in a large range (3000mm x 3000mm) and rapid speedThe main content of this thesis includes: 1).This thesis deeply analyzes the principle of two laser-beams measurement, directional reflection, and identification of target. This thesis also constructs relevant mathematical module and builds a theoretical foundation for future research; 2). This thesis adopts DC brushless motor and analyzes its performance in detail and introduces the development of the peripheral control circuit for this motor. This circuit, although simple, owns many advantages including multiple function, strong controlling ability, easy debugging, and lost cost. This circuit has been validated by experiments; 3). An optical system and a device to fix the laser source are developed to optimize and simplify the structure of this system. By replacing the rotation of laser source with the rotation of flat mirror, the goal of four laser-beam measurement is achieved; 4).The sensing of measured target and the collection of information can be achieved by introducing red light semiconductor laser as light source, Fresnel lens with large caliber and short focus as receiving lens, and PIN opto-electronic diode as detector; 5).CPLD and AVR are introduced to achieve the goal of high-speed and real-time processing of signal with a 50MHz crystal as the clock; 6). the principle of perspective transformation is used to realize the self-calibration of measuring system. The analysis and calibration of the error in this system are also presented in this thesis.