Research And Design Of The Color Mark Detection Photoelectric Sensor System

Color mark detection is an important basis for characterizing the accuracy of moderngravure printing system. In order to resolve the problems of the poor performancecomplicated manual operation and the lower detection accuracy of the conventional colormark detection sensor, this thesis presents a design scheme of the color mark detectionphotoelectric sensor system. The new color mark detection photoelectric sensor system isbased on a microprocessor core, with integrated photovoltaic module, weak signalprocessing module, signal acquisition module and the communication module. Thissystem is able to complete the selection of the optimal light emission, converting opticalsignals, weak signal detection, programmable gain, setting the signal threshold isautomatically, the signal A/D conversion and two-way communication and otherfunctions.System uses a high-performance, low-power, low-cost8-bit PIC series enhancedMCU as the core chip, which integrates A/D converter, CAN communication,communication module RS-485interfaces, simplifying the hardware design of the system.Using low-noise photoelectric conversion circuit and filter circuit, effectively enhance thesignal to noise ratio of the system. The use of low-noise preamplifier circuit, will be usefulto amplify weak signals to appropriate level. Using double edge detection algorithmdetects the moment of the center position, which raises the detection accuracy of thesystem. Using A/D sampling conducts programmable gain and signal threshold setautomatically. By using the coaxial reflective optical system and the mechanical structureof the shield to reduce the influence of disturbance light.By the analysis of color mark detection photoelectric sensor system design on theabove, we set up the simulative overprint system platform. Through hardware andsoftware debugging, this system ultimately achieves the basic functions of the color markdetection. The research and design of this thesis optimize the operation of the sensor, improve the range of color mark detection and meet the specification requirements of thecolor mark detection photoelectric sensor system in high-speed overprinting.