| Smartongue system is a novel electronic tongue researched by our laboratory which consists of sensor array, signal excitation and reception circuit and intelligent algorithm. Smartongue system has been used in several fields, such as wine identification, tea grading, milk monitoring and pathogen detection. Based on earlier research, this research has been systematically studied the stability of Smartongue industrialization key technology via stability of sensor array's reference electrode, stability relationship between sampling frequency and sampling signal, excitation signal stability and integrity of sample detection software. The main research work and results are as follows.(1) Research on the stability of Smartongue sensor array's reference electrode.Ag/AgCl reference electrode is not suitable for industrialization application of Smartongue because of its leakage. The detection stability of platinum electrode and Ag/AgCl electrode was researched by detecting four drink samples. The result showed that the ability to distinguish samples of these two reference electrodes does not have significant difference. The singular value ratio of platinum electrode were 13.9%,11.7%,14.4%,16.1%, and average value was 14.0%. Ag/AgCl electrode's value were 13.3%,12.2%,19.4%,12.7% and average value was 14.4%. Platinum electrode is better in this situation. As the advantage of platinum electrode, it will be used as the reference electrode to solve stability problem in industrialization application of Smartongue.(2) Research on Smartongue sampling frequency.As the correlation between sampling frequency and realism of sampling signal, an appropriate sampling frequency was needed to decrease the signal distortion and raise system stability. Lab VIEW was used to design four sampling frequencies of Smartongue,500,1 K,10 K and 20 K, respectively and four green tea samples were detected in this experiment The result showed that the reception signal authenticity, sample identification ability and stability of repeat testing are the best in 20 K sampling frequency. Therefore,20 K will be used in further application to raise stability of sampling signal.(3) Research on Smartongue excitation signal.Because of physical limitation of waveform, square wave can not be excited stable in practical application. So, a novel signal should be designed as excitation signal of Smartongue. The envelop signal based on sine wave as excitation signal of Smartongue was established and its detection stability was compared with pulse signal in this research. The result showed that envelop signal can identify both different kinds and same kind samples effectively. The identification value of these two signals are 25.7 and 26.1, both have a good effect. Meanwhile, for repeat detection stability, envelop signal is better than pulse signal. Therefore, multi-frequency envelop signal will be used as excitation signal to solve the problem of signal excitation and repeat detection stability.(4) Research on Smartongue detection software.Novel version detection software of Smartongue was developed via GUI and Data Acquisition Toolbox and has been put in practice. Compared with the earlier software, it was the first time to achieve data real time transmission between Matlab and Access database and integrate with Smartongue data processing software. The stability of data transmission and processing would be improved by using this software.In summary, this research proved the application stability of Smartongue effectively by solving key technologies of stability of reference electrode, sampling signal, excitation signal, data transmission and processing. This research laid the basis of Smartongue industrialization. |
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