Control And Application Of Vending Machine Based On Embedded System

Vending machine is known as “24-hour super shop-assistant”.It is a high-tech product that developed in Japan,America and Europe in the 1970 s.In 1992 vending machine entered China.Since then this way of sale has been gradually accepted by Chinese.With the development of science and technology,the vending machine in China has constantly improved and the request of vending machine becomes more and more high.Existing vending machines in China use spring goods structure for commodity push and use an unmovable goods receiving platform for commodity receive.So the goods in the machines have many limitations.They can only sell commodities which are light and not easy broken,such as drinks,snacks and magazines.The machines don’t have a common communication protocol,data collection or data analysis,people can only use traditional currency to buy commodities,that leading to a high cost of maintenance and inconvenience.This thesis introduces the design ideas,analyses the vending machine’s work and divides the entire system into two parts: the goods transmission system and the host computer and peripherals.By analyzing the entire electrical system,goods transport system and pick-up system,the thesis designs a new type of goods transport system and pickup system,making the vending machine sell goods which have various sizes and weights as well as fragile items,introducing the bill machine,coin device,MDB/ICP communication protocol,Alipay payment mode and data collection system,realizes the control of vending machine using embedded systems.The contents of this thesis are as follows:First,the thesis introduces and analyzes the goods transmission system from six aspects: the control circuit design,power supply design,speed control of motors,goods delivery and pickup design and host computer and peripherals.Using single-chip to control the various components,using filter,switching power supply and DC-DC voltage regulator chip to ensure the stability of the voltage of each device,using PID control algorithm for motor control,using a new push module and using a movable receiving platform to transmit goods so that the machine can sell goods of different sizes and ensure the goods in good condition,using a highly precise pressure sensor in the pick-up platform to detect goods to improve the accuracy of detection,using a rotatable product exit door,saving space to improve the user experience and using a light curtain to prevent hand clamping,analyses the function of the bill machine and coin device,lists their specifications and characteristics and selects suitable ones,present Alipay payment,fully introduces the MDB/ICP communication protocol and shows the difference between it and the common serial protocol,draws a software flow chart and introduces the data collection system;Second,the thesis analyses the whole structure of the machine,draws the overall control flow chart,and does voltage stability test,cash coin identification test and commodity transmission test.The research shows that using embedded systems to control the whole system,designing a new push module and a movable receiving platform to deliver the goods to pick-up platform,using a highly precise pressure sensor to detect goods and a rotatable product exit door in the pick-up module,adding Alipay to payment method for customer to buy commodities,communicating with peripherals by way of the MDB/ICP protocol in line with the international standard.These allow the vending machine to sell goods of various sizes and weights as well as fragile items with low maintenance cost.