Study On None Guidance Precision Displacement Measurement And Calibration System

Displacement measurement is the most elementary and most important measurement in mechanical field. In displacement measurement, it is widely believed that light wavelength is the most precise criterion. Using the laser wavelength as the benchmark of displacement measurement, usually the interference or diffraction method be taken, in fact, the interference method is the only way that be taken to measure the large displacement or to orientation along the light transmission direction. Using interference system means that the light can' t be interrupted, therefore, real interferometers are all equipped with a precision mechanical guidance along the measuring direction and the guidance length depend on the measuring tasks, This is a disadvantage for laser interferometer to use on long distance measurement.Using laser interference technique, but reducing the dependence to mechanical guidance or even not use guidance is our aim.The main work and new ideas of this dissertation are in the following: 1. By researching the basic characteristics of interference measurement, and analyzing the interferometer' s working principle and measurement system of the heterodyne double frequency laser interferometer, thisdissertation researches the two dynamic tracking methods which can be realized possibly in measurement system and brings forward the tracking methods of laser beam tracking and target mirror tracking.2. Tracking speed, technical difficulties and practicability etc of different tracking method are considered, both theoretically and researched experimentally. Then technical planning of "outer placing tracking orientation measurement system" is put forward and developed, and the expected results are obtained.3. Dummy guiding track of catenary navigation with target mirror track is presented and researched theoretically and experimentally aiming at the requirement, scene and feasibility of measurement, and the expected results are obtained.4. The guidance method and the system structure of "double-catenary benchmark" are presented, and the single thread pendency expressed by distance between two catenaries is deduced. Experiment verified the feasibility of this method.5. Principle and disadvantage of multi-wavelength laser absolute distance interference measurement are gone deep into, and then the author present own opinions and views about these problems.