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1、毕业设计毕业设计（ （论论文）文）报报告告题 目 基于单片机的电子换号牌的设计 系 别 专 业 班 级 学生姓名 学 号 指导教师 22013 年 4 月无锡科技职业学院科技论文The application of electronic nose0The application of electronic noseAbstract: positive human olfactory organ is a complex physiological reaction. Nature kind of odor tens of thousands, even professionals specia
2、lizing in odor identification work is often recognition errors.Keywords: electronic nose computer technology developed olfactory organs physiological reaction “Customs“ security monitoring neural networks odor sensor identification infrared sensorIntroduction: The electronic nose developed a high-te
3、ch products is simulated animal olfactory organ, scientists are still not all clear principle of the animals sense of smell. However, with the development of science and technology, more authoritative some universities in the world have developed electronic nose has a wide range of applications, mos
4、t notably to the number of the University of Hamburg, Germany, has absolute authority in the sensor field in the world today. Electronic nose is the response pattern to identify the odor of the gas sensor array electronic systems, it can be in a few hours, days or even a few months time within a con
5、tinuous, real-time monitoring of the specific location of the odor condition. Identifying odor main mechanism of the electronic nose is that each sensor in the array has a different sensitivity of the measured gas. The core of the device of the electronic nose gas sensor. Gas sensors based on the pr
6、inciple of different type of metal oxide, electrochemical, and conductive polymer type, quality, photo-ionization type can be divided into many types. Currently the most widely used is a metal oxide.How it works:Electronic nose is mainly composed of three parts of a gas sensor array, signal pre-proc
7、essing and pattern recognition. Presented in front of an active material of the sensor, an odor sensor chemical input is converted into an electrical signal by a plurality of sensor response to an odor they constitute the sensor array to the odor of the response spectrum. Obviously, the various chem
8、ical components in the odor sensitive materials play a role in this response spectrum for a broad spectrum of odor response spectrum. To achieve the odor qualitative or quantitative analysis, the sensor 无锡科技职业学院科技论文The application of electronic nose1signal must be appropriate pretreatment (to elimin
9、ate noise, feature extraction, signal amplification, etc.), using a suitable pattern recognition analysis method for processing thereof. Theoretically, each odor will have its characteristic response spectrum, according to its characteristic response spectrum can distinguish between small same odor.
10、 While gas sensors constituting the array to measure the cross-sensitivity of a variety of gases, by a suitable analytical method, the mixed gas analysis. The electronic nose is the use of various gas sensing device has a response to this characteristic but different from each other, with the data p
11、rocessing methods to identify a variety of odor, odor quality analysis and evaluation of complex component gases. The main mechanism of the electronic nose identify each sensor in the array has a different sensitivity of the measured gas, e.g., high response One gas may be generated on a sensor, whi
12、le the other sensor is a low response; Similarly, the 2nd gas generating high response of the sensor is not sensitive on the 1st gas and, ultimately, the entire sensor array response pattern is different for different gases, it is this difference, to enable the system to identify a gas according to
13、the response of the sensor pattern. Electronic nose can be summarized as follows: the sensor array - the signal preprocessing - neural networks and a variety of algorithms - computer identification (gas qualitative and quantitative analysis). Functionally speaking, the gas sensor array is equivalent
14、 to the biological olfactory system in a large number of olfactory receptor cells, neural network and the computer to recognize the biological equivalent of the brain, the rest is the equivalent of the olfactory nerve signal transduction system. For example, the measurement of the metal oxide semico
15、nductor (MOS) gas sensor in response to the schematic diagram of the voltage signal. MOS gas sensor is usually before the test shall be heated to 2500 (or higher) in order to work properly. After the chemical reaction occurs in the testing process, the MOS gas sensor and the sample gas / odor, will
16、change its own gas sensitive film conductivity and resistance values, leading to a terminal voltage of a sampling resistor in series thereto is changed. Due to sampling resistor is fixed, so the immediate extraction of the end of the sampling resistor voltage signal voltage MOS gas sensor response curve.无锡科技职业学院科技论文The application of electronic nose2图 1Features:Electronic nose response time, speed detection, unlike other instruments, such as
