吹扫式仿生嗅觉检测装置的设计与性能试验

为研究仿生嗅觉检测装置的检测性能,该文研制了一种吹扫式仿生嗅觉检测装置,选取传感器阵列灵敏度、响应时间和恢复时间作为装置性能指标,分析了传感器加热电压、待检气体湿度以及流量等控制参数对嗅觉检测性能的影响,并进一步验证优化控制参数的仿生嗅觉检测装置对气味检测的可行性和检测性能。试验结果表明:传感器阵列灵敏度随加热电压增大而增大,其响应和恢复时间随加热电压增大而减小,加热电压为5.0 V时,装置性能较佳,其传感器阵列灵敏度分布范围为2.260~4.823,响应和恢复时间分布范围分别为46~53 s、44~70 s;增加气体湿度会使传感器阵列灵敏度减小,同时也会延长响应和恢复时间,气体相对湿度为30%时,装置性能较佳;传感器阵列灵敏度随载气流量的增加先递增后减小,其响应和恢复时间随流量的增加先减小后递增,流量为100 m L/min时,装置性能较佳,其传感器阵列灵敏度分布范围为2.853~7.559,响应和恢复时间分布范围分别为35~50 s、30~50 s;在优化控制参数下,待检气体体积分数范围控制在0.002%~0.020%时,装置检测灵敏度较高,范围为3 577.1~6 700.7;线性特性和重复性较好,决定系数范围为0.901~0.997,变异系数范围为0.832%~9.696%,能满足仿生嗅觉气味检测的要求,可为后续开展仿生嗅觉的应用性研究提供数据参考与技术支撑。

Design and performance experiment of bionic olfactory detection device using purging method

Abstract: In order to study the performance of bionic olfactory detection device, the bionic olfactory detection device was designed using purging method in this research This detection device consisted of the gas transmission and flow control pipes, the bionic olfactory control unit and the software of bionic olfactory detection analysis. The gas transmission and flow control pipes were the carrier of bionic olfactory gas transmission, and the bionic olfactory control unit completed the signal output and sensor signal acquisition, the software of bionic olfactory detection analysis could not only complete setting up parameters in the process of olfactory detection analysis and controlling working process, but also complete data preprocessing, feature extraction and pattern recognition. According to current documents, the heating voltage of sensor array, gas humidity and gas flow have an effect on the performance of this device. In order to study the effect of these control parameters on the performance of detection device, the ethylene and nitrogen gas were respectively selected as testing sample and carrier gas, and each of the control parameters was studied with single factor experiment. Then, according to the sensibility, response time, recovery time of sensor array, the optimal control parameters of this device were selected. Furthermore, the feasibility and performance of the bionic olfactory detection device were verified under optimized control parameters. The results of experiment showed that the sensitivity of the sensor array increased with the increase of heating voltage. When the heating voltage of sensor was 5.0 V, the sensibility of the sensor array was the maximum, which ranged from 2.260 to 4.823, and the response and recovery time of the sensor array were both the minimum, which ranged from 46 to 53 s and from 44 to 70 s, respectively. So when the heating voltage of sensor was 5.0 V, the detection device could get a better performance. When the humidity increased, the sensibility of the sensor array decreased, and the response time and recovery time of the sensor array were both lengthened. So, when the relative humidity of the gas was 30%, the detection device could get a better performance. The sensibility of the sensor array firstly increased and then decreased with the increment of the gas flow; the response time and recovery time of the sensor array firstly decreased and then increased with the increment of the flow. If the sensitivity, recovery time and recovery time of the sensor array were comprehensively considered, when the flow was 100 mL/min, the sensibility of the sensor array was the maximum, which ranged from 2.853 to 7.559, the response and the recovery time of the sensor array were the minimum, which ranged from 35 to 50 s and from 30 to 50 s, respectively. So, when the flow was 100 mL/min, the detection device could get a better performance. Therefore, when the heating voltage of sensor was 5.0 V, the relative humidity of the gas was 30%, and the flow was 100 mL/min, these control parameters were the optimal control parameters. The detection device adopted the optimized control parameters, and then the device was used to detect the ethylene gas with the volume fraction of 0.002%, 0.004%, 0.006%, 0.010%, 0.020%, 0.030%, 0.040% and 0.050%. The results showed that when the volume fraction was controlled in the range of 0.002%-0.020%, the sensibility of the device was higher, which ranged from 3 577.1 to 6 700.7, and the linearity and repeatability of the device were both better, whose coefficient of determination was from 0.901 to 0.997, and coefficient of variation ranged from 0.832% to 9.696%. So, the device can meet the requirements of odor detection, and also can provide data reference and technical support for the further research on the application of bionic olfaction.