Research On Photoelectric Diesel Vehicle On-line Smoke Meter

At present,my country’s automobile exhaust pollution supervision methods mainly adopt traditional methods such as annual vehicle inspections,road random inspections,or citizens’ reporting.The above-mentioned supervision methods not only have the problems of low detection efficiency and poor real-time performance,but also require a lot of manpower and material resources,and cannot solve the problem of excessive vehicle exhaust emissions in a timely manner.In order to improve the deficiencies of the existing exhaust emission supervision methods,it is urgent to carry out related research on new automobile exhaust detection methods to achieve efficient and real-time exhaust emission supervision.Therefore,this paper proposes an online smoke detection system for diesel vehicles,which is used to realize the real-time measurement of vehicle exhaust smoke,light absorption coefficient and other parameters,and transmit the data to the host computer for visual display in real time.The main research work of the thesis includes:(1)Develop a design plan for on-line detection of diesel vehicle exhaust smoke.According to the particle pollutant detection method to determine the measurement principle,a smoke measurement method based on the Lambert-Beer law is proposed for on-line detection of diesel vehicle exhaust smoke.Combining photoelectric detection technology and embedded system technology,design the system structure and function,and formulate an online detection program for diesel vehicle exhaust smoke.(2)The hardware system design of diesel vehicle exhaust smoke on-line detection.Based on the design principles of the light path and the smoke path,the system mechanical structure design is carried out,and the installation position of the sensor is determined.In order to achieve the functions of laser emission and optical signal acquisition to obtain the signal quantity required for online smoke detection,this paper proposes a system hardware circuit design plan.The main design modules include control unit,laser drive,optical signal acquisition,temperature measurement,CAN communication,etc..(3)Design of software system for on-line detection of diesel vehicle exhaust smoke based on u C/OS-II.In order to achieve different control requirements,the software tasks are divided first,and system tasks such as laser driving,optical and temperature signal acquisition,data processing,and CAN communication are determined.In order to realize the overall system function,it is proposed to transplant and debug in u C/OS-II operating system.(4)System test and experiment.In order to verify the performance of the diesel vehicle exhaust smoke detection system designed in this paper,experiments of system hardware test,system stability and accuracy were carried out.The experimental results prove that the diesel vehicle exhaust smoke on-line detection system designed in this paper has good stability,and the maximum measurement error is within ±2%,which can meet the measurement requirements.