9.3.3. Object evaluation

In order to decide which object is to be used for distance control, an evaluator value is calculated for each object.

The following are the two most important criteria for this calculation:

• Position and movement of the object relative to our vehicle. The closer the object is to our vehicle and/or the faster it is approaching, the higher the evaluator value.
• Presence of the object in our lane. The radar sensors cannot detect the actual lane or the lane markings on the surface of the road. The information from the camera-based system installed for the Lane Departure Warning system is not yet available for ACC Stop & Go. Therefore, ACC Stop & Go computes a probable course for the lane ahead of the car. While the car is on the move, variables are used in this process that describe the motion of the car and the position of motionless objects detected by the sensors. If the car is at a standstill, computation is based primarily on analysis of the signal from the steering angle sensor. This means that steering wheel movements while the car is at a standstill produce changes in the lane calculated by the ACC Stop & Go function and have a corresponding effect on evaluation of the detected objects.

The object with the highest evaluator value is used for distance control. In this step in processing, the objects are also classified by their evaluation status. A distinction is drawn between moving and stationary objects. The control algorithm has a special way of treating objects which have been classified as stationary after first being detected.