On-line Measuring System For Large Dia.Straight Welded Pipe Based On LabVIEW

The large Dia.Straight welded pipe is widely used in the world because of its unique advantages today,along with the application deeper,the requirement of increasing the quality of steel pipe is urgent,especially,the shape bending and distortion level is weighting factors to be considered good quality.Measuring for large Dia.Straight welded pipe of geometric straightness and section circularity(shape and position error)were not solution well at home and abroad,but the on-line measuring of large Dia.Straight welded pipe is an important part of pipe alignmented today,they are also technical difficult problems.Usually we measure them with hands,this don't meet the demand of welded pipe alignmented with automation and digitization.Under this conditions,we were asked to design the large Dia.Straight welded pipe shape and position error on-line measuring system by Tianshui Metalforming Machine Tool Co.,Ltd.The on-line shape and position error measuring system was developed on large Dia. Straight welded pipe.LabVIEW was used to be software platform,this make the equipment meet openness requirements,it is well established for its flexible operations in terms of measurement control and data acquisition.At the same time,the measuring equipment use PC as the industrial control platform,the data processing is more convenient,data store and recycle is more easier,and the human-computer interface is more humanization.We use PC as control platform,many of computer hardware are modularized,this reduces the development costs,at the same time,the development efficiency raised.At the terminal,we use displacement sensor to measure the parameter of shape and position error on pipe,the measuring signal is amplified and noiseisolated by signal conditioning modules,at last,the signal become date signal that the data acquisition card can be read,so the computer can analyze the collected data.This paper emphasizes the mechanical driving method,mathematical model establishment and data processing,human-computer interface of pipe measuring system.The mechanical driving design includes whole measuring tentative design,goalpost design, adjustable turning rolls design and calculation.We create the time domain 3-point method error separate model of pipe generatrix straightness and domain 2-point method error separate model of pipe section roundness,also we use VI LabVIEW as soft platform,building the program of data acquistion processsing and save.At last,we creat easy operation human-computer interface,and use date to simulation analysis data processing module,It can provide reference for equipment's design and manufacture.This research project ranged over many topics,the measuring system consider many factors,and the time of design and research is limiting,so the measuring system is difficult to avoid disadvantages,at the same time,the measuring system should be continuously improved on many details,when it is after use.For now,the future research directions and consummate content is:mechanical driving system should be rationalized,the optimization of data processing model,human-computer interface become more fully human,the computer controlled system,and in further,the shape and position error measuring system of pipe is the prospective research of full digital pipe straightener.