Intelligent grading and sorting system for international letters

The invention discloses an intelligent grading and sorting system for international letters. The intelligent grading and sorting system comprises a letter sorting box, a driving mechanism, a supporting frame, a letter conveying belt, a fixing frame, a letter separating mechanism, an infrared detector, a foreign matter recognition detector, a sorting manipulator, a sorting conveying belt and a control integration system. The working principle is characterized in that the technology of automatic arrangement, automatic transmission, intelligent positioning and automatic sorting is adopted; aiming at the international letters, the international letters are stacked in a pneumatic grabbing mode, and automatic conveying and positioning are conducted; and meanwhile, integrated foreign matter recognition and detection equipment conducts detection and outputs a result, a PLC control protocol is adopted for signal conversion and integration, intelligent positioning is fused to drive the mechanical arm to grab the positi