Research On Self-detection Intelligent Algorithm And Hardware System Design For Gas Sensor

In recent years,the fog haze weather makes the importance of human attention to the quality of the atmospheric environment.The improvement of environmental quality is a long-term work.The environmental investigation and monitor are needed before making governance programs.Environmental monitoring is the use of the advanced monitoring technology and monitoring equipment to understand the environment,which directly affects the decision-making of the environmental governance program.Therefore,reliable and accurate atmospheric environmental monitoring is critical to the management and protection of the atmospheric environment.In order to achieve the monitoring of the atmospheric environment,a set of intelligent portable atmospheric detection system is developed.The research of the system mainly includes three aspects: the design of the system hardware circuit,the GUI(Graphical User Interface)human-computer interaction interface and the research of the self-test intelligent algorithm.The system hardware mainly includes the gas sensor array drive circuit,signal conditioning and data acquisition circuit,information processing unit circuit,intake part of the control circuit,external interface circuit.The main controller uses the F28335.The chip not only achieves the control of the external circuit,but also meets the algorithm transplant operation.By the gas sensor array drive circuit,signal conditioning and data acquisition circuit,the intake part of the control circuit and the external interface circuit constitute a digital signal acquisition circuit which provides the original data for the subsequent use of intelligent algorithms to deal with data and human-computer interface display.The data is the source of data flow.The human-computer interface gives up the commonly LCD display.GUI interface is based on QT which is similar to the interface of the phone,flat panel and is more real and beautiful.The system features is a high degree of integration and achieves fool-style operation.Use the QML rendering interface.The establishment of C + + function library can complete the interface operation.The non-blocking design meets the front and back run at the same time.Users can control the C ++ function through the operation interface trigger signal.It realizes the communication of the data and control behavior between the main controller F28335 and GUI interface.It realizes the control of the hardware circuit.The system uses the combination of principal component analysis(PCA),support vector machine(SVM)and support vector regression(SVR)to achieve the identification of atmospheric gas.PCA filter out the noise signal in the collected data to improve the accuracy of the gas sensor.The principal component analysis(PCA)is used to preprocess the response data of the gas sensor,and the mixed information is filtered out by reducing the dimension thereby reducing the noise of the signal.Support Vector Machine(SVM)is a learning classifier,which establishes the sample classification model and the support vector regression model of concentration by training data set training.It uses the test data to test the establishment of the model.MATLAB is used to debug self-test intelligent algorithm to achieve the data processing and the display of the image result.According to the structural characteristics of the sensor and the experience of the experts,the failure mechanism of the sensor is analyzed in depth.Using support vector regression algorithm builds the model to achieve fault diagnosis and recovery.In order to detect the normal operation of each function of the system,the four groups of experiments were designed with four kinds of gas as the detection object.The data is analyzed by MATLAB and human-computer interaction.The experimental results show that the system has high accuracy in gas identification and concentration testing,and it is simple in operation and is low in cost.It has a good application prospect.