The Research And Implementation On Key Technologies Of Digital Leveling System

Leveling is the basic method to measure the height difference between two points on the ground using the level and the leveling staff,and the leveling instrument is widely used in the field of leveling and engineering measurement.Because the error of leveling directly affects the accuracy of leveling results,more and more attention has been paid to the verification of the leveling system(the host of leveling and the staff).With the development of level measurment technology,the leveling instrument has been developed from the traditional optical level to the digital level,and the measurement accuracy has been greatly improved.However,relative to the optical level,the error source of the digital level is also much more complex,and the verification regulation and verification instrument of the traditional optical level are not applicable to the digital level.At the same time,due to the different manufacturer uses different identification algorithm of the bar code,the host of leveling needs to be used with the specific leveling rod.Therefore,the accuracy of the system can better reflect the measurement accuracy of the digital leveling.However,most of calibration equipment used on digital leveling are aimed at single error at home,so,it is urgent to design a set of equipment for measuring the accuracy of digital leveling system,and to improve the verification regulations of digital level.In this paper,the key technology of calibration equipment used on the digital level measurement system is studied:(1)The background of verification technology of the digital level measurement system has been analysed at domestic and foreign,and the principle,characteristics and defects of the verification method have been compared.At the same time,a new scheme of the calibration on the digital level measurement system is designed,and the feasibility of this method are analysed on the principle.(2)The remote protocol of the digital level been widely used in the current market is studied,and the automatic reading of digital level is realized.In order to avoid the limit in the large distance communication from PC and digital leve.The module of ZigBee to serial port is designed to achieve the function that the resault of digital level is read by wireless.(3)In the process of digital leveling system verification,the accuracy of benchmark must be precise.In this paper,based on the principle of laser interferometer,the influence of atmospheric parameters on the measurement of laser interferometer is analyzed.And aiming at the problem of temperature gradient in the measurement environment,the real-time dynamic compensation algorithm of the laser interferometer is designed.At the same time,the meteorological station system is designed to collect the atmospheric parameters in the measurement environment to compensate the laser wavelength.(4)Aiming at the specific movement mode of the leveling rod,the control system is designed.And based on the Delphi to design the digital level verification system to achieve the automatic verification of digital level,and generate the final verification report.It is verified by experiments that each unit meets the requirements of system verification.And the whole system will also be completed.