Research And Development Of Electronic Tongue System Based On TMS320F28335

As a substitute and continuation of human taste,electronic tongue has been increasingly used in the food industry for food safety and quality analysis,providing a fast and real-time detection method.The electronic tongue consists of three parts,namely taste sensor array,signal acquisition system and pattern recognition system.The array of taste sensors is analogous to the tongue and makes contact sensing of the tested solution with different "tastes".The signal acquisition system acquires excitation signal on the array of taste sensors,which is similar to neurosensory system.The pattern recognition system that works like a brain extracts the characteristics of the signal,which is used to distinguish different solutions or determine their taste characteristics.However,the domestic research is currently concentrated in universities due to the high cost and narrow application scenarios.In this paper,an improved electronic tongue testing principle is applied on the basis of summarizing previous studies.The principle is to apply pulse excitation signal between the working electrode and the auxiliary electrode,and to collect the excitation voltage between the reference electrode and the auxiliary electrode,which is used to characterize the characteristics of the sample under test.Combined with the software of slave computer,the function of electronic tongue system including pulse signal transmission,ADC data acquisition and data transmission is realized by configuring GPIO,timer,ADC and SCI modules of TMS320F28335.The PC software part is written in C#,which mainly realizes functions such as data reprocessing,result saving and visual display.In terms of data processing,minimum distance discriminant method is adopted to realize the classification function of tested samples,and linear fitting result is used to realize the taste analysis of samples.In order to validate the electronic tongue system,different NACL solutions were analyzed firstly using working electrodes composed of different metal electrodes,which verifies the feasibility of the scheme.Secondly,the classification ability of the electronic tongue system was verified by using five solutions including 2% saline,2% sugar water,rice wine,liquor and fruit wine.Furthermore,the electronic tongue system was applied to the compounding of NFC citrus juice.The quality of 19 kinds of citrus juice was analyzed combined with the results of cluster analysis,which provides some reference for the selection of Citrus Varieties in the compounding of NFC citrus juice.