| With the rapid development of China's electronic manufacturing industry,the domestic demand for surface mount technology(referred to as SMT)Mounter continues to rise.At the same time,because of the monopoly of foreign technology on SMT machine equipment.All of these make the market price of SMT machine is overpriced,and the enterprise's production cost is too high.Therefore,research and development with independent intellectual property rights of the domestic high precision ultra-high-speed placement machine has become an important mission of China's manufacturing industry.Feeder is used as an important component in the placement machine for conveying mounting elements,and the feeding speed and precision have a direct impact on the placement accuracy of the mounter.If the feeder cannot guarantee the accuracy of feed and feed efficiency,the product failure rate will rise and seriously affect the quality of the product.The feeding control system will have a direct impact on the feeding accuracy and efficiency of the feeder,but there is a lack of systematic research on the feed control system in china.Therefore,the design and implementation of high speed and high precision SMT feeder control system in the field of advanced manufacturing has great engineering application prospect.In this paper,the practical problems in the enterprise,how to improve the accuracy and efficiency of feed control system is studied.The research mainly includes the following aspects:(1)Design of the feeding control system.On the basis of the existing feeder structure,the feeding position detection module is added to realize the real-time detection of the feeding position by using the photoelectric encoder.In addition,the position detection circuit and the software program are designed to ensure the feeding accuracy of the feeding system at high speed.(2)Research and design of the hardware system of feeding control system.The hardware circuit of the feeding control system is composed of two modules,the control module and the communication module,wherein the control module comprises a microprocessor,a feed speed control circuit and a feed position control circuit.The communication module comprises the communication between the main control unit and the communication unit of the feeder,the communication between the feeding system and the high speed and high precision chip mounter,and realizes the hardware function required by the control system.(3)Research and design ot the software system of feeding control system.Aiming at the problem of "out-of-step" phenomenon of the existing feeding system at high speed,the compound control algorithm based on the interpolation algorithm and the acceleration and deceleration algorithm combined with the PID closed loop control is studied,which solves the problem of "out-of-step".On this basis,the software design of the whole feeder control system is completed,including control module,communication module and man-machine interface.Finally,the high speed and high precision control of the whole feed control system is realized.(4)The hardware and software of the feeding control system are realized,and the test is carried out on the high speed and high precision placement machine to verify the stability,the feed rate and the precision of the feeding control system.Experimental results show that the resistance of the 0402 package in the machine feeding control system for feed rate is 52000 per hour,compared with the same type of feeding control system for feed speed is increased by 6.7%.And feed accuracy control within ±0.03 mm.Resistance to the 0603 package in the machine on the feeding control system of feed rate is 36000 per hour,compared with the same type of feeding control system for feed rate increased 8%,feeding accuracy control in less than ±0.06 mm,which reached a high speed and high precision SMT patch precision.The feeding control system designed in this paper is reasonable in structure and high in stability,which lays a good foundation for the research of feed control system. |
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