Collision Mitigation Brake System

The Collision Mitigation Brake System ( CMBS ) is a collision warning and protection system from the automobile manufacturer Honda .

The primary purpose of the CMBS is to protect against rear-end collisions and to minimize damage to the occupants in the event of a rear-end collision.
CMBS is active from a vehicle speed of 15 km / h, a speed difference of 15 km / h to the vehicle in front and can be deactivated manually by the driver. Furthermore, strong steering movements are interpreted as evasive maneuvers and the CMBS switches off.

The system was first introduced in 2003 in the Japanese Inspire model. It has been built into the Legend in series in Germany since 2006 . The third generation of the CR-V has been available since January 2007, and the eighth generation of the Accord has also been available since June 2008.

functionality

The CMBS measures the distance to the vehicle in front using a millimeter wave radar. This radar is hidden behind the Honda emblem in the radiator grille and has a range of 100 m and a detection angle of 16 ° in the direction of travel.

The radar measures the distance and the relative speed to the vehicle in front. In addition, the data from the vehicle's speed, yaw rate and steering angle sensors are evaluated. The CMBS calculates the further probable path of the vehicle from the vehicle's own data. This information and the information about the vehicle in front are used to determine whether a potentially dangerous situation exists. If such a dangerous situation exists, the TTC ( T ime T o C ollision; time to impact ) is calculated. This TTC is calculated from the distance between the two vehicles divided by the speed difference between the two vehicles.

A distinction is made between three levels based on the TTC:

Warning level 1

TTC ≈ 3 s

"Brakes" appears in the information display on the dashboard, and an acoustic signal also alerts the driver to the dangerous situation.

Warning level 2

TTC ≈ 2 s

Warning level 2 occurs when the distance between the vehicles decreases further. In addition to the optical and acoustic signals, the CMBS gives the driver a tangible signal. This signal is realized by repeated pulsing tightening and loosening of the belt by the belt tensioner. It is used to wake the driver from a possible microsleep.

In addition, the CMBS brakes the vehicle with 25% of the full braking power. If the driver now applies the brake, the CMBS regards this as emergency braking and activates the brake assistant to optimally brake the vehicle.

Warning level 3

TTC <1 s

The rear-end collision can only be prevented by the car in front (accelerate immediately or leave the lane). The CMBS prepares the occupants for the impending collision. To do this, it pulls the seat belts of the people sitting in front and brakes the vehicle with 60% of the maximum braking power. If the driver now applies the brake, the CMBS (with the help of the brake assistant) initiates emergency braking.

swell

Honda press release (October 2006)