Study On The Key Technologies Of FTP Method In Engineering Measurement

3D object surface measurement is an important method that people obtain the data of the object surface profile. In many measurement methods of 3D object surface profile, machine vision has come to people's attention by reason of simpleness, convenience and high availability of data obtainment. This thesis studies the key technologies of FTP method in engineering measurement.The thesis mainly consists of the following contents:(l)Referring to internal and overseas literature, the developments of the internal and overseas noncontact measurement is known. The theory of FTP method is learned. And the key technologies of FTP method in engineering measurement are pointed out.(2)Phase unwrapping method is studied. Two phase unwrapping methods are used, which can quickly get the real phase.(3)More steps are made for the method of calibration. For the difficult problem of the plate (x, y) calibration, the selection of drones is studied. It makes the system more convention and the precision improved.(4)The factors that affect the projective grate are analyzed and the selected conditions of grate parameters are putted forward. The compound phase will be acquired by means of frequency conversion grate. At the same time, the flexible filter is studied.(5)The factors that include the error caused by the calibration order, the phase error caused by the problem of depth of field and the error caused by the object slope are analyzed. And the errors caused by the other factors are also studied.(6)Base on the above key technologies and by means of the results of theory research, a software system and a hardware system are integrated into one system. The hardware of system includes LCD, CCD camera, and image card. At the same time, Visual C++ 6.0 is used as the developed tool, the software of system includes the functions of system adjustment, system calibration and system measurement.(7)The height calibration and the plate calibration experiments are done. The precisions of the system calibrations are acquired. And the standard cylinder is also measured. The measurement proves the veracity of the system measurement.(8)The discussed work for large-scale measurement is done.