Research and design of raw silk evenness detector based on CCD image sensor

Abstract

In this paper, a dynamic measurement system of raw silk evenness based on machine vision is introduced. When the raw silk is moving at a certain speed by a drive device, the raw silk images are continuously captured by image acquisition system including a Charge Coupled Device (CCD) line sensor, a telecentric lens, a light source. To extract the main body of the raw silk accurately, the raw silk images are processed sequentially with threshold segmentation, morphological opening operation. And then the raw silk evenness is characterized by calculating the coefficient of variation (CV value) of diameter. Different image processing methods are discussed. When compared with the existing measurement and assessment of raw silk evenness, such as blackboard manual eye inspection and capacitance-detecting technology, the measurement method using machine vision has following characteristics. Firstly, because the image capture equipment is linear CCD with high resolution, the dynamical measurement of raw silk evenness can be realized with high speed. Secondly, the telecentric lens is adopted in the designed raw silk evenness measurement, which can eliminate the influence of the jitter of raw silk along the optical axis when image capturing. Finally, the high quality raw silk image can provide the information about raw silk after image threshold segmentation and morphology operation.