BAS PLUS, function - GF30.30-P-3310LEA

ENGINES 156, 272, 273, 275, 629, 642 in MODEL 221 up to 31.8.10 with CODE (239) Autonomous intelligent cruise control Plus Light as of model tear 2010/YoM 09 model refinement package

Fig 1: View Of Accident-Critical Situation Detection

Courtesy of MERCEDES-BENZ USA

Accident-critical situation detected by the BAS PLUS (Brake Assist System PLUS)

BAS PLUS function requirements, general

Autonomous intelligent cruise control Plus Light coded in central gateway control unit (N93)
Long range radar soiling and function test completed
Circuit 61 ON (engine running)
Gear range "D" engaged
The vehicle is moving forwards
Accelerator not operated

BAS PLUS, general

The BAS PLUS function is an additional function of the Brake Assist System (BAS), which assists the driver during emergency braking by means of specific calculations of the brake force for a given situation.

The data from the radar is used to continuously calculate the potential risk of a collision. If the driver brakes heavy in a critical situation, the brake force is (if necessary) boosted so as to avoid a collision (within physical limits).

Function sequence for BAS PLUS

The function sequence is described in the following steps:

Function sequence for braking torque computation
Function sequence for activation
Function sequence for an accident-critical situation
Function sequence for deactivation

Function sequence for braking torque computation

Sensor data from the radars and input signals are evaluated by the radar sensors control unit (SGR) (N62/1) and the necessary braking torque is calculated to support the Brake Assist System. The calculated braking torque is sent over the vehicle dynamics CAN (CAN H) to the ESP control unit (N47-5), which adjusts the brake pressure as required through the traction system hydraulic unit (A7/3).

The required braking torque is continuously recalculated by the radar sensors control unit on the basis of the current distance and the closing speed, and is relayed to the ESP control unit. A partial braking right up to emergency braking of the vehicle can occur depending on the situation.

Function sequence for activation

The BAS PLUS is activated if a critical accident situation is recognized after braking forcefully.

Function sequence for an accident-critical situation

At the current closing speed, the distance of the vehicle from a detected object (vehicle) is detected as critical for an imminent collision. Such objects can be objects in motion in front of the vehicle. Stationary targets are not recognized.

Function sequence for deactivation

If the driver applies significant movement to the brake pedal again, at a certain threshold value, brake assistance is withdrawn until braking is by the driver alone (depends on brake pedal travel) and BAS PLUS is deactivated. The BAS PLUS function is also deactivated if the accelerator pedal is operated.

If the function requirements for the BAS PLUS are no longer fulfilled or a fault is detected, BAS PLUS is deactivated.

Function as well as failure of BAS PLUS is not indicated to the driver.

	Component description for ESP control unit	N47-5 Model 221.0/1	GF42.45-P-5118LE
	Component description for radar sensors control unit	N62/1	GF30.30-P-3301LEC