A Methods Study Of Laser Tracking Distance Measurement System

Laser tracking interferometry, which is a developing absolute distance measurement technology, is extensively applied in large-scale high accuracy assembly and inspection of product lines in aerospace, automobile, machine building and water and electricity construction. An integrative structure is mostly used in LTS design because of easy fulfillment. However, you have to rotate the laser head and interference system in order to obtain continuous beam in measurement operation and can not utilize the existing laser interferometer performing tracking measurement in practice. Furthermore, some factors such as different instruments having different centers of gravity, heavy deadweight and large moment of inertia affect the tracking performance seriously. Therefore, it is significant and urgent to develop a LTS independent of laser interferometer (That is methodology of outside installation mechanism in laser tracking measurement system).The principle of outside installation mechanism in laser tracking measurement system is introduced and a spherical mechanism method is adopted to design the 2D tracking circumrotatory mechanism according thedevelopment of laser tracking measurement system in global. A measurement scheme is proposed by theoretical analyzing and experiment, which is a mutidiscipline method relating to optics, precision mechanism, electronics, computer science and control technology. In the designing of the controller, a fourfold phase photoelectric battery is used as the photoelectric incepted sensor, an ADuC812 chip is used to sample data and a incomplete numeric differential PID arithmetic is adopted in the control system.Methodology for absolute measurement is proposed by using an outside installation mechanism in laser tracking measurement system, which has an important reference value in practicality in high accuracy assembly and inspection of large-scale mechanical field. Spherical tracking servo mechanism' s model described in this paper not only is a new thought but also have much reference value in the mechanical design and other industrial machines design. Through experiments analysis, it is found that the integrated LTS is the most versatile laser tracker available for dimensioning, tool building, alignment, and reverse engineering applications with the characteristic of high tracking precision and excellent dynamic capability. This paper also provided an effective new method and technique in the application of large workpieces and industry field measurement and orientation by using dual- frequency laser interferometer.