Research And Accuracy Analysis Of Precise Dimension Measurment On Axis Part Based On Image Processing

It is estimated that the total production of axis part is at least 1 billion in China. About 70 percents of the part need to be measured and inspected. But at present the measuring technology in many factories is just taking use of mechanical measuring instrument or optic instrument with human vision. That may directly cause a lot of failing such as inefficiency, low precision, unreliability, high cost and other defect.With the development of modern industry, the intellectualized,high-speed and high-precision measuring technology on axis part is required. And CCD and image processing technology is widely applied in measuring and inspecting field, which not only ensure measuring precision and efficiency, but also-avoid artificial error.Though analyzing massive reference on linear CCD and actual application of machine vision in measuring field, the main research work is focused on the research of precise dimension measurement on based on image processing. The master thesis will include the following main contents:(1)using Prewitt operator to detect part's initial edge .On the basis of this, disperse data of intensity gradient is processed by the method of Least-squares curve-fitting for obtaining precise position of part's edge .(2) To reduce disturbance of noise, light source and other reason ,the measuring data is processed according to error theory. Select correct measuring data and calculate average in order to obtain precise measuring data.(3) Aim at decreasing error effect caused by the distortion of lens and other factors. The calibration of function is constructed through the known multi-dimension axis part as reference. The calibration is applied in measuring to achieve precise measuring.