The Control And Calibration Of The Scanning Probe In Petroleum Pipe-Thread Measuring

With the fast development of the petroleum industry, the traditional petroleum pipe-thread measuring methods could not meet the measuring need because of their shortcomings such as low precision, bad commonability, complex operation, not easy to realize automatic measurement and could not compensate for the metrical error. Therefore, it's necessary to develop a new method to measure all the petroleum pipe-thread parameters quickly and accurately. This subject is just for this aim.According to the principle of three-dimensional measurement, utilize contemporary advanced numerical control technology, the subject structure an open numerical control system of "the PC + Motion Controller", and utilize the scan characteristic of the scanning probe to achieve scanning measure and automatic searching centre measure on the petroleum pipe-thread. Then analyses the measuring data and get the series parameters of the petroleum pipe-thread.The article describes the control system and measure system briefly, shows the structure and principle of the scanning probe in details, gives the mathematics model of probe calibration, and discusses some control methods of scanning probe in details. Especially in the aspect of applying to the petroleum pipe-tread measurement, gives theconcrete implementation method of scanning measure and automatic searching centre measure. Finally, analyses the anti-jamming ability and stability of the whole system.The traditional methods are used in the petroleum pipe-thread measuring at present. Somebody study on the pitch and pitch diameter measure used coordinate measuring method, but adopt the scanning method, it's the first time at home. To the scanning measurement of other complicated workpieces with space curved surface, it has very important referenced value.