Study Of The Bus Spontaneous-Ignition Detection-Warning System Supplied By Vehicle Networkand Fire Spread

As is well known to all, serious casualties caused by the bus self-igniting will bring huge hidden troubles to public transportation. On the one hand, the bus is short of facilities that accurately detect the self-igniting risks in time. On the other hand, owing to lack for the spread law of the bus combustion and blank of reliable theoretical basis on disaster prevention, passengers can not escape dangers effectively which results in heavy damages. Because of the above two contents, the following researches are carried out:Firstly, the historical bus self-igniting accidents are investigated and analyzed. With the conclusion of the four major dangerous sources and their positions, the detection parameters, the types of the sensors and their arrangement positions of the self-igniting discriminance are determined.Secondly, the vehicle sensor network based on CAN-bus communication technology and the information management system PC is designed to detect the bus engine compartment fire hazard and manage the bus running information,Through the hardware circuit design of the master-slave node of CAN-bus in the sensor network and software development as well as the wireless communication technology, the real-time communication between the vehicle-mounted module and the PC companied with the real-time information management in the PC is realized.Thirdly, in order to detect the self-igniting in the bus engine compartment, the fuzzy threshold value comparison method and the fixed threshold value comparison method are proposed to realize the first level discrimination. At the same time, for the principle of the system stability, the cusp mutation model to achieve the second level discriminance is built. The experiments prove that this system can accurately response within60s after the self-igniting. Finally, the experimental platform which integrated with the vehicle sensor network, wireless communication and the the PC information management system and based on the vehicle network architecture theory is constructed. Then the discriminance method and the early warning system are tested with the bus engine compartment self-igniting data. In the meantime, the three dimension model of one bus is built to simulate how the fire spread in the bus by the FDS software. The variation of the burning temperature, the smoke and the poisonous gas is analyzed. And it provides the reference for the bus self-igniting emergency and disaster prevention in the future.