The Experimental Research On The Dynamic Techinique Of Grade Rod

The grade rod is the length measurement implement of geodetic measurement,which is widely used in geodetic measurement and engineering measurement,its precision directly influence the measurement result of veracity and stability. However, due to the bad using environment of grade rod, its length maybe be changed,we must test its precision periodically.There has been a kind of new advanced grade rod in the world since several years ago,which can collect data automatically. Recently, the new advanced grade rod has been fetched in to our country, but we don't know its dynamic measurement method and the related report is rarely seen in public. Therefore, Researching its testing method and equipment is extremely necessary.Firstly, double frequence laser interference is presented,new collimation method is applied in this dissertation. In order to realize auto-measurement,MCU is used to arrange the work separately. The grade rod dynamic test system is mainly consisted of the measurement moving system,double frequence laser interference,optics-electric collimation system and computer data-collection system.High-precision and dynamic measurement of the grade rod can be achieved and the testing efficiency is also improved at the same time.As the main difficulty of the dynamic measuring system, the collimation system is analyzed and studied mainly in this paper. We studied four collimation methods,analyzed their advantage and disadvantage, devised its collimation triggering circuit .Based on the analysis of experimental data, the best collimation method is optimized and designed. The placidity of the measurement moving system is closely related to measurement precision, so we analyzed moving placidity and studied why it affects measurement precision.In order to assure the precison of the whole system,a method of measurement moving system is presentd on the basis of lots of many experiments..Electric-interfering affects the precision of the system, so it is important to analyze the reasons of producing electric-interfering and study how to restrain it.It is proved by many experiments that the system can measure the grade rod dynamicly and its measurement precision satifies need of the project.