Design Of Large Diameter Steel Pipe Welding Speed Detection System Based On Laser Ranging

Laser as active measurement of media and energy, has been widely applied in industrial inspection and real life. In recent years, the image sensor is introduced into the laser measurement system, laser image analysis of the measured object by using image processing techniques, to obtain a more accurate distance information, the range of applications has been expanded so that the measuring system.By analyzing the propagation characteristics of laser and technology related to image processing, image displacement measurement method based on laser is put forward. Using a certain Angle of two beams of laser irradiation, the object to be tested using image sensor to collect surface reflection of laser light spot image object to be tested, by PC on the analysis of image processing to obtain two laser facular spacing, fitting out of light spot spacing and the mathematical relationship between the distance being measured. In order to achieve the above measuring methods, the choice of532nm green laser and CCD image sensor, design the hardware circuit based on MC9S12XS128microcontroller as the control core, using A/D conversion of video decoding chip TVP5150. AL422B is used as data buffer FIFO. Under the MATLAB image processing platform design algorithm is used to convert a machine pass the image by the binarization, median filter, such as pretreatment, a circle fitting method is used to calculate the image spot center spacing value, thus fitting out the calculation formula between distance and displacement. Design light spot spacing, the displacement and the PC interface of real-time display of welding speed, according to the actual processing conditions, set up different welding conditions. In the PC serial port reserved welding speed feedback information, can according to the change of welding speed on motor speed in real time correction.Via testing different environment and actual measurement, the displacement of the proved in this paper, the design of the system can real-time detect200cm-500cm. displacement changes within the scope of measurement error is less than1cm. The system has a non contact, convenient, fast, low cost, stable characteristics, has certain use value.