The Research Of Intelligent Electronic Nose Based On ARM7

The tea is closely related to people’s life. Moreover, the west lake longjing tea is famous tea in China. With the improvement of the west lake longjing awareness, shoddy phenomenon is very popular in the market. However, in the method of evaluating and tea, people distinguish the pros and cons of tea mainly by sensory evaluation. But changes in external factors are very easy to affect human’s sensory sensitivity, thus affecting the accuracy of the final detection. Therefore, rapid and accurate detection of tea quality factor is of great significance.This paper puts forward the research of intelligent electronic nose based on ARM7 processor.Electronic nose is one of emerging technologies developed in recent years. Electronic nose technology research has received the widespread attention, such as in the food safety detection, atmospheric environment, biological, medical and so on, and have a wide range of applications to various fields. The advantage of electronic nose technology is that it can make up for the subjectivity of traditional senses. And electronic nose technology with short detection time, good repeatability characteristics, to some extent, can simulate human nasal sense the aroma of tea and give the overall evaluation results, is currently the inspection trend.This paper aims to develop a system of intelligent electronic nose to detect the quality of tea. The development of the electronic nose system divided into two parts, hardware circuit design and software system development. The electronic nose system is mainly composed of three parts in this paper, which are the data acquisition unit based on sensor array, data analysis processing unit with micro controller LPC2138 as its core, and Pattern recognition unit based on algorithm. Micro controller ARM7LPC2138 is used as the core, because it is rich in feet, processing speed and reasonable price. The hardware circuit comprises a power supply circuit, a sensor driving circuit, an analog digital conversion circuit and a communication interface circuit. The data were processed by two methods such as Principal Component Analysis(PCA)and Support Vector Machine(SVM)in the algorithm to analyze relationship between the various raw materials of tea. The host computer uses the Lab VIEW which can us the graphical interface to display the collected data in real time, and the collected data are processed by the MATLAB algorithm, and the data are analyzed to improve the accuracy of the recognition.In this paper, four groups of different levels of Longjing West Lake tea were adopted as the research object, to distinguish the different grades of tea through the pattern recognition technology. According to the aroma characteristic of Longjing West Lake and the working principle of the intelligent electronic nose system based on ARM7 processor, the method of distinguishing the different grades of Longjing West Lake tea by using electronic nose system was studied. The sensor array is used to detect and enhance the adaptability and selectivity of the sensor. The experimental results show that the electronic nose technology can do very well in distinguishing different grades of tea, verify the feasibility of electronic nose technology in the detection of tea.