BMW 7 Series: New Warning Function

In the F01/F02, the Adaptive Brake Assistant is supplemented by a warning function. This useful "collision warning" is designed to draw the driver's attention to hazardous situations in good time. The driver is then assisted by the subfunctions of the Adaptive Brake Assistant, which provide optimum deceleration in this kind of emergency situation.

The driver is able to switch the collision warning on and off. Its state (on/off) remains stored for the duration of the current driving cycle (key-specific).

The field of application in which the collision warning offers the greatest benefit to the customer is as follows: The customer is driving behind a vehicle that brakes suddenly and hard.

If the customer has activated the collision warning, he is given notification in two stages that a hazardous situation has been detected and the customer is thereby prompted to intervene:

• Advance warning
• Acute warning.

The time at which the warning has to be issued is, again, calculated by the long-range radar sensor based on the collision avoidance deceleration. Each warning stage has its own threshold values.

Fig. 150: Setting Warning Time

Setting the advance warning

In the event of an advance warning, powerful braking by the driver is sufficient to allay the situation. If the acute warning is issued, the driver must brake immediately and with maximum force to avoid a collision.

The driver has some control over the threshold value for the activation of the first stage, the advance warning.

From an Assistant window in the Central Information Display, the driver is able to select one of three warning times for the advance warning:

• Early
• Late
• Off (no advance warning given).

For the collision warning, the ICM control unit is responsible for the following control tasks. The switching on and off, the activation conditions, the fault monitoring and the adjustment of the warning time are all computed by the ICM. In addition, the ICM control unit forwards the warning request from the long-range radar sensor to the instrument cluster and (if fitted) the head-up display, where the warning is issued.

Issuing of the warning

Fig. 151: Display Instrument Cluster For Collision Warning

INDEX REFERENCE CHART

1. Stage 1: Advance warning
2. Stage 2: Acute warning

The advance warning is represented by the red car symbol in the instrument cluster. In the event of an advance warning, it lights up constantly. As there is no audible signal, this visual warning signal is the only signal for the advance warning.

In the event of an acute warning, the car symbol in the instrument cluster begins to flash. Since an immediate intervention by the driver is required, this visual signal is supplemented by an audible tone.

Fig. 152: Display - Collision Warning In Head-Up

INDEX REFERENCE CHART

1. Stage 1: Advance warning
2. Stage 2: Acute warning

This particular high-frequency tone is used only for the acute warning and differs distinctly from other tones that are issued, e. g. with Check Control messages.

If the vehicle is equipped with the head-up display, the visual displays of the collision warning are seen by the driver even more directly and therefore even sooner.

In the head-up display, the advance warning is represented by a significantly enlarged red car symbol. As with the instrument cluster display, the advance warning is indicated by the symbol lighting up constantly.

In the event of an acute warning, the car symbol in the head-up display begins to flash. At the same time, the parts of the display that are irrelevant to this emergency situation are hidden so as not to distract the driver unnecessarily. These displays include those of the navigation system, for example. As soon as the acute warning is over, all the displays in the head-up display re-appear. The same distinctive tone for the acute warning is used in vehicles with head-up display.

NOTE: The collision warning is active only if the driver has switched it on at the driver assistance systems operating unit.

As the advance warning is the first warning stage, its timing is configurable but it can also be switched off.

Fault states

The functions of the Adaptive Brake Assistant depend on the faultless operation of the long-range radar sensor in particular, but also of the ICM control unit and the DSC unit. If one of these essential system components is limited in its availability in any way, these functions may no longer work correctly and would need to be deactivated.

The driver is given notification of this condition. If, for example, a fault is present at the time the system is switched on, the function illumination of the collision warning will not be activated. From this, the driver can infer that the collision warning is not available.

If a fault were to occur some time after the system was switched on, the driver could fail to, see the function illumination go out. For this reason, a Check Control message is issued as an additional warning measure. There are two different symbols, and each one is supplemented by a relevant instruction.

FAULT STATES

Collision warning deactivated (due to unfavorable operating conditions, e. g. dirty long-range radar sensor)

Collision warning failure (due to genuine faults or defective components)

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