Research For Automobile Exhaust Pollutants Detecting System Under ASM

Along with the increase of automobile amount, the automobile emission has become the major pollution source in city. In order to protect environment and raising the life quality of the people, administering the automobile emission becomes the important work of government departments. Advanced country experience indicates that implementation the I/M's system is the most effective method of controlling pollution for administering the automobile emission. I/M's system requires testing the in-use vehicles regularly, and if the automobile can't pass the test, it is required to maintain the auto.The methods of idle speed and double idle speed for detecting exhaust pollution are extensively being used at present, but this detecting mode is the testing of idle speed mode only. Under idle speed mode although emission volume consistency of pollutant is more bigger than other mode, the proportion of idle speed emission of the automobile isn't much. Because the proportion of idle speed operation time is smaller. It is the necessary that the automobile must be in the conditions of the fixed loading operation mode when detecting. At the same time the idle speed testing can not detect the content of NOx and not respond to the control requirement of modern society yet. In order to solve this issue the Acceleration Simulation Mode (ASM) is established.This paper takes GB18285-2000 as the basis, this system chooses the LabVIEW software of American NI corporation and the VC++ software, using virtual instruments technology and independently designing out that the automobile exhaust pollutant detecting system, the file management system and the initial control system for electricity whirling flow dynamometer under the ASM. The system is designed for the testing application development, using independent paddle type data acquisition (DAQ) card, silicon controlled rectifier rectification circuit and dynamic link library (DLL) technology. It has realized the loading capacity of real-time control electricity whirling flow dynamometer or chassis dynamometer, and gathers at the same time the various parameters that the system needed , and after analysis the collate to make a whether or not qualified conclusion for the vehicle under ASM.In the engine rig and the ASM exhaust pollutant practice has been done, and the detecting system relies on the data which is acquired by DAQ to prove that the detecting system is feasible and effective.This system possesses the following characteristic:1, This system possesses the friendly man-machine interface and easy operation, and the soft maintenance is convenient .2, Use VC++'s development dynamic link library , and realizes the call to the dynamic link library of LabVIEW , and realizing drive the DAQ, and satisfying the needs that the real-time data acquisition and data controlling .3,The file management system can be realized the full course and manage. The system canbe printed the checkout result, and can preserve the data in order to prepare for the analysis of data.4, The system can be realized control the input voltage of Chassis dynamometer .5, This system has reduced the development cost , and has raised the precision of the testing and controlling. The development of application possess fixed popularization and use value.