Research And Design On The Sysytem Of Multi-channel Data Acquisition And Surface Reconstruction

With the emergence of the embedded technology, people’s urgent requirement is toreduce the cost and improve the reliability of data acquisition system. Data acquisitiontechnique which based on embedded system becomes a new research hotspot. Throughthe combination of the embedded technology and sensing technology, this thesis designsa windscreen quality testing system which based on digital displacement sensor. Thetesting system adopts the multi-channel data acquisition technique and also canreconstruct the physical prototype through using the surface reconstruction technique.The main works of this thesis are summarized as follows.Firstly, this thesis take the samsung’s S3C2440A as the data acquisition system’shardware core processor, on this basis, the overall design scheme of the data acquisitionsystem which based on S3C2440A and capacitive digital displacement sensor ispresented, including the overall design scheme of the single channel data acquisitionsystem and the multi-channel data acquisition system. Through researching and analyzingthe basic structure and working mechanism of the capacitive digital displacement sensor,the interface circuit of the S3C2440A microprocessor and the capacitive digitaldisplacement sensor is developed, the measuring circuit of the single channel dataacquisition system and the multi-channel data acquisition system is also presented.Secondly, through analyzing and comparing the basal theory and method of surfacereconstruction, we find the deficiency of Bezier method and B-spline method and takeNURBS as the essential method of the surface reconstruction. On this basis, throughresearching the process of the NURBS curve and surface interpolation, the steps of theNURBS curve and surface interpolation are gived in this thesis.Finally, the software design of the data acquisition system is presented. The dataacquisition programming is based on embedded C. Through researching the basicalgorithm of the NURBS curve and surface, this thesis develops a NURBS curve andsurface reconstruction software in VC++ environment using the OpenGL technology. Itadopts the visualization technology and Object Based Programming conception.