Study On The On-line Test Technology Of Weld Width In Metal Bellows

In this paper, aiming at the special development request of metal bellows weld surface quality's on-line detection system, the key technology in the system implement process, which is the on-line test technology of weld width in metal bellows, is studied.Firstly, with the item request and actual condition of industry spot, domestic and international weld test technology studying and developing present condition is analyzed, and weld width in metal bellow is measured through adopting visual inspection method.Secondly, in the foundation of analyzing visual inspection & image processing technology and principle, combining the request, index of the system, the built detection system flat is totally studied, the principle and the hardware type choosing of each part is analyzed and introduced. The exactitude obtaining of test image should be assured by hardware to lay good foundation for the following-up image processing and measuring.Thirdly, on the foundation of the system flat, realization the related technique and method of width measurement is studied as key point. Firstly from the collected images, according to the characteristics of low contrast of weld image and great background interference, the prepared processed method is studied. For further getting the edge of weld to measure the width, the edge detection methods in common use are analyzed and studied. In this foundation, aiming at the studying of inside weld, through analytical comparing to experiment result, these methods all can't satisfy the request of examination.Fourthly, aiming at the characteristics of weld image and the structure characteristics of test equipment, the method of laser locating double boundary synchronous tracking is adopted. Through regulating hardware light circuit, a laser image and a weld image are collected and get. In the foundation of analyzing image characteristics, according to weld characteristics and laser imaging characteristics, laser image is processed. The position of weld is found out from the laser image, and is transferred to weld image. Double boundary synchronous tracking is carried on and get edge of the weld, then the width is measured. Through the experiment studying, the measured data is given, the usefulness of the method is explained.