Research Of Remote Pavement Structure Performance Testing System Based On Virtual Instrument

In china, the semi-rigid asphalt structure is frequently and widely used in the construction of highway pavement, which makes it inevitable to learn its performance. The study about the performance of the semi-rigid asphalt pavement structure is made by simulating the real pavement through a small-sized structure specimen, embedding sensors in the internal structure and collecting the experiment data by using virtual instrument testing technology.In this paper, the virtual instrument is based on PXI bus. A multi-functional virtual testing system is built, in which the embedded controller and PXI multi-functional data collection card is the instrument hardware platform, the LabVIEW is the software development platform and SCXI is the signal conditioning circuit. Firstly, this paper introduces the definition, characteristics, components, and the developing tendency of virtual instrument and then the developing enrichment of LabVIEW. Secondly, in accordance with the requirements of the testing system, it discusses the testing theory, the selection and embedment of the sensor in testing system. The focus of the paper is to study the testing system from the two aspects of software and hardware. Building the hardware platform from the three parts of sensor circuit, signal conditioning modules, data module, the core of Data acquisition is PXI-6070E multifunction data acquisition card; the software uses modular design and the functions of the system are subdivided into different function modules, including parameter initialization, bridge balance, filtering,time and frequency domain analysis, data storage, signal replay, experiment report generation, system operation by calling different function modules, signal acquisition, data processing, data analysis and results display. Finally, based on the tendency of the networking testing technology now, the paper analyses the remote testing realization of TCP/UDP,Web Server,DataSocket technology in the local area network(LAN). Through comparing the performances of these three technologies, DataSocket are chosen to realize the remote operation of the test. Using this system to testing different thickness asphalt pavement structure, obtains the semi-rigid type base asphalt pavement mechanics response rule from the empirical data analysis with temperature and the load factor.