Abstract: An illustrative example method is for estimating a friction characteristic of a surface beneath a vehicle that has a plurality of wheels contacting the surface. The method includes determining a wheel speed of at least one of the wheels, determining a velocity of the at least one of the wheels separately from determining the wheel speed, determining a wheel slip of the at least one of the wheels based on the determined wheel speed and the determined velocity, and determining the friction characteristic based on the determined wheel slip. Determining the velocity separately from the wheel speed is accomplished using at least one detector that provides an output corresponding to a range rate, such as a RADAR or LIDAR detector.

Abstract: An illustrative example method is for estimating a friction characteristic of a surface beneath a vehicle that has a plurality of wheels contacting the surface. The method includes determining a wheel speed of at least one of the wheels, determining a velocity of the at least one of the wheels separately from determining the wheel speed, determining a wheel slip of the at least one of the wheels based on the determined wheel speed and the determined velocity, and determining the friction characteristic based on the determined wheel slip. Determining the velocity separately from the wheel speed is accomplished using at least one detector that provides an output corresponding to a range rate, such as a RADAR or LIDAR detector.

Abstract: A driver assistance system for a vehicle having a decision engine and a plurality of active object-detection sensors including two radar sensors mounted at opposed locations on the vehicle relative to a longitudinal centerline of the vehicle. A field of view of each radar sensor is directed away from the centerline and forward of the vehicle and overlaps with the field of view of the other radar sensor in a region of overlap crossing the centerline forward of the vehicle. The decision engine receives signals from the sensors and determines the presence of an object in the regions of overlap on the basis of signals from only each of the two radar sensors among the active object-detection sensors of the system. The decision engine is thus able to command vehicle functions such as braking or acceleration on the basis of the determination.