The core processing component of the automotive electronic nose system is the single chip microcomputer AT89C52. It is a detection system that contains gas and temperature / humidity sensors. For analog signal acquisition and processing using four kinds of sensors, including DS18B20 type temperature sensor, SMC-2 type humidity sensor, QMNJ-9 alcohol sensor and AF30L/38L type smoke sensor. The temperature inside the car is detected by a temperature sensor, the detection results with LCD display; temperature / humidity sensor can fast accurately collected inside wet / temperature, to prevent the rear window fogging frosting effect of passengers and the driver's line of sight, the alcohol content of the interior is collected by the alcohol sensor, after the results by the MCU. After treated with the set value are compared, the results of more than set value, at this time can not drive, the system will immediately send alarm; smoke sensor is monitoring the car smoke content and concentration of the role, if there is a fire condition, alarm circuit to send out alarm signals in time. And, when the temperature or the vehicle is detected in the smoke gas content exceeds the set value, automatically start the ventilation system to carry out the car gas cycle. This design uses four kinds of sensors, can realize the car body of all analog information collection and processing, with high measurement accuracy, accurate operation, reliable operation.
Key words: single chip microcomputer; gas detection; sensor; signal processing; alarm circuit
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