Development Of Instrument For Measuring Chaser With Linear CCD Based On DSP

The tubing is applied widely on oil field, and the quality of tubing thread connection effects on normal oil production, thus the quality of chaser effects on the tubing thread production. Because the chaser is high precision and complex graphics, we still use the optical amplification and manual examination methods to detect. The methods are instability and inefficient.In this paper, the instrument for measuring chaser with linear CCD based on DSP is designed on the comparisons and analysis of the various tools and thread detection technology. The instrument obtains 2-D data of the chaser profile section by linear CCD using optical projection and machine driving, and work out its results by DSP system, then the system displays them with LCD, The measuring system is combined with optics, mechanics and electronics.The paper presents a method associated linear CCD with stepper motor to realize high precision measurement basing on DSP. The main contents and results of this paper are as follows: Analysis the structure of the chaser outline and carry on mathematics modelling the theory value; The principle of the instrument for measuring the chaser is introduced; According to theory and application of CCD, design the driving and sampling, processing circuit for High Precision Linear CCD TCD1501D; Design driving and sampling circuit for high precision linear CCD based on P89LPC932A1, study and test the feasibility of linear CCD driving and sampling, processing circuit. The results show the drivers can assort with CCD well, take advantage of the characteristic of CCD photoelectric transition and output steady and reliable electric signal; Design and test the instrument hardware and program of measuring and controlling system using to measure the chaser with CCD based on TMS320LF2407A. The system is high precision, fast, stable. Video processing and power circuit can obviously restrain the main noise, enhance SNR and obtain high quality video signal for further signal processing; Study the method to find the turn of external profile line of tubing thread blade, and least squares procedure is employed to fit the external profile line, the grades operator is used to detect the edge of image; The measuring errors have been discussed, and the correlative solving methods have been brought forward.