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Blow-out Monitoring And Brake System

by Jinyu Hou, Clemson University Automotive Engineering Graduate Student

Basic Description

Blow-out monitoring and brake system is one of the automotive active safety systems invented by Geely in 2004, which is designed to prevent vehicles from going out of control due to a tire blowing out at high speed. Tire blow-out is a significant cause of vehicle collisions on highways all over the world.

When tire blow-out occurs (eg. right front wheel), rolling resistance of front right wheel increases while rolling resistance of front left wheel is constant, which causes the vehicle to start to turn towards the clockwise direction. In a front wheel blow-out, the steering wheel is also influenced by the moment turning to right. Under this situation, driver will instinctively turn the steering wheel, however, this can easily separate the tire from the wheel rim so that the appearing lateral force will make vehicle slip. After a tire blow-out, it is difficult for the driver to control the vehicle.

Blow-out Monitoring And Brake System

Braking the vehicles in time can always effectively avoid the accident above, however, human being always cannot react that fast. Thus blow-out monitoring and brake system becomes necessary. Generally, a BMBS consists of tire pressure monitoring module, ECU, audible warning alarm and braking system. If tire blow-out happens with the vehicle speed higher than 50 mile/hour, BMBS starts to work. Built-in tire monitoring module, which real-time monitors the pressure, speed and temperature of tires, will immediately send the abnormal signal to ECU. Then ECU will judge the signal and make the actuators work: progressively braking the vehicle with the support of ABS (Anti-lock Braking System) and EBD (Electric Brake force Distribution) to avoid the phenomenon of wheel lock deviation, spin and drift; and alerting the drivers with audible warning system. The total time of this process is ranging from 0.2 to 0.5 seconds, which is much faster than the common response of human brain.

Blow-out Monitoring And Brake System

For the reason that BMBS is the unique technology developed by Geely, this system now can only be found in cars of Geely. However, with time going, this technology must be applied to all vehicles to completely eliminate worry of risk of tire blow-out.

Air pressure sensors, temperature sensors, wheel speed sensors
Audible warning alarm, Brake
Data Communications
Data communication between tires and control unit: typically 315 MHz RF link.
Wake-up signal to tire mounted sensors: typically a low-frequency EM signal.
Control unit communications: typically CAN bus
For More Information
[1] Tire Blowouts become top causes of car accidents,
[2] China's Geely Blow-Out Monitoring &Braking System(BMBS), YouTube, Feb. 1, 2008.
[3] Chinese Car Geely BMBS for Life, YouTube, July 6, 2008.