Research On Technology Of Intelligent Vision Sensor For Blister Packaging Drugs Automatic Visual Inspection

These years the visual sensor which also called intellective camera become more and more hot in the field of computer visual technology. As it is consisted of image sensors, digital signal processor, communication interface and I/O controlling unit, which can be used in image acquisition, image processing, information transmission and I/O controlling. To adapt the stricter requirements brought by the quality controlling during the modern industrial production, the automatic visual inspection technique which has higher precision, noncontact measuring and higher intelligent controlment is widely adopted in online inspection and intellective controlment. In this paper, the technique of visual sensor is researched, the sample of visual sensor is manufactured which adopted the CMOS image sensor based on DSP plus CPLD to fulfill image acquisition, image processing and the I/O controlling, and also the data communication based on built-in USB port of DSP is designed and fulfilled. For the real-time inspection requirement of the blister drugs product line, the experimental system for automatic visual detection based on the developed visual sensor sample is established, with the research for the surface image processing algorithm of blister drugs. The research focused in this paper and the completed works are shown as follows:1. The circuit of the visual sensor based on DSP TMS320VC5509A was designed, which can fulfill all functions in it such as image acquisition, image processing, data communication and I/O controlling.2. The built-in USB communication port was developed and fulfilled, and the interrupt handling part based on DSP was coded, including the software of USB drive based on the WDM structure, which implements the USB interface enumeration and data communications.3. The software system of the visual sensor was designed, and the programs used for image acquisition, processing and transmission of the visual sensor was designed and run by DSP, which implements the real-time response to the external sampling order and getting the I/O output signal through the analysis of image processing, also the applied program for PC which could fulfill the real-time display of the movinig image and inspected result of the blister drugs was designed.4. An overall framework of the automatic visual inspection system used for the blister drugs was designed, the optoelectronic module and the vision sensor complete the image acquisition and image processing, the signal of processing results was given to PLC module, and a special light source was designed.5. The algorithm of the blister drugs surface image processing was researched and the image filtering, gray enhancing, threshold segmentation, edge detection, goal marking and the geometric characteristic measurement were designed and achieved. The Hough transform algorithm for rapid circle detection of the known-parameters was discussed.6. Two series of experimental system were designed, one adopted the transmission lighting mode, which aimed at the real-time inspection of the blister drugs which without covered aluminum foil, and the other adopted the reflective lighting mode, which aimed at the real-time inspection of the blister drugs covered aluminum foil package. The inspecting accuracy and the system's speed satisfy the design requirements.