Gas Sensors In The Application Of Passenger Car Air-conditioning Control System

With the development of science and technology and the improvement of people's life, more and more passenger cars has become common used and people also goes by the long staying in the car. For the narrow room, high tightness inside cars, the air quality can be easily polluted by fuel emissions, decoration smell and artificial smoking. The air pollution inside cars has posed a new threat to the vehicle drivers and passengers, in order to solve the problem; the paper has applied the gas sensors into the air-conditioning control system in the car.There are two intelligent vehicle network sensor modules, a main control module and four gas sensor conditioning circuits are designed in the paper. A single chip intelligent sensor module mainly is composed of Single chip AT89S52, Controller AD7862, MAX232 and SJA1000 etc. Another ARM intelligent sensor module is formed by Chip LPC2378, Interface SP3232EEA , JTAG, Controller TJA1040 and High-speed coupler 6N137 etc. the master controlling intelligent sensor module the same as the ARM intelligent sensor module .it expect that externally connected with the driving modules ,an keyboard, LCD and ventilation system. Three intelligent modules connect with the CAN-Bus, two smart sensor modules mainly provide the gas concentration detected by the gas sensor to the master intelligent module, and the master module will determine the pollution level as soon as it receives the information, and displays the current gas concentration if not exceeded, while gives alarms and controls the output of wave PWM when exceeded, driving two DC fan's operation, changing the air between inside and outside the car.Paper first introduces the research theory of the subject's basis, practical significance, domestic and international situation and tendency, then describes the design and implementation of system hardware and software, finally checks the system design possibility according to the analysis of on-site test. The gas sensors designed in the paper has a certain value in the application of passenger car air-conditioning control system, the study also has great significance in air quality monitoring in vehicle room environment and social, physical security and other issues goes by.