Deflection Basin Methods Based On Linear Array CCD Detection

Deflection is important indicators of the overall strength of the road ground of highway.Deflection testing and evaluation must be made during acceptance and the completion of thehighway’s construction, and road maintenance management by deflection testing device:falling weight deflection apparatus (Falling Weight Deflectometer, abbreviated FWD). FWDnot only can detect the maximum deflection of the test points, but also can test the overallstrength of deflection basin. This study describes in detail that the working principle and testperformance of FWD, analyses the deficiencies of its use. So the deflection testing methodbased on linear array CCD (Charge Couple Devices, charge-coupled components) is proposed.This method not only can overcome the disadvantages of sensor which be used to existingtesting but also can improve further detection accuracy.For the road deflection basin based on linear array CCD detection method of study, themain research works are summarized as follows:1. Carried out a comparative study about the deflection testing methods and the workingtheory at home and abroad, and analysis the advantages and disadvantages of theimplementation technology. Therefore, these lay the research foundation.2. Proposed deflection basin detection methods based on linear array CCD, detailed thedeflection basin center and the rest of the points of deflection testing sensor works. Thismethod can improve the accuracy of detection, achieve that deflection test has nothing to dowith road surface vibration frequency and measure the whole deflection process. Thecalibration can be completed by users.3. Developed the deflection testing based on the optical displacement sensor with lineararray CCD. Designed the driving circuits by using Altera’s programmable logic devices togenerate timing pulses. Utilized the filters and amplifiers in the signal output processingcircuit. Completed the data communication between single-chip interface and a host to ensurethe data security and fast transfer.4. Achieved displacement tests based on the optical displacement sensor with linear arrayCCD. The results show that the deflection basin based on linear array CCD detection methodscan meet the test requirements, obtain the dynamic ground deformation information, and helpto learn more about the ground deflection under load changes.