Automatic sensor azimuth alignment

A method of automatically correcting for any misalignment of a forward-looking sensor mounted on a host vehicle while the host vehicle is moving on a vehicle path adjacent a target, the sensor making periodic readings and each reading including a set of range and azimuth angle measurements of the target, the vehicle further including a path prediction unit which provides path data representative of the direction of travel and the speed of the host vehicle, said method comprising the steps of:

• a) processing a set of said range and azimuth angle measurements and estimating the target location point;
• b) repeating step (a) for a plurality of readings over a segment of said vehicle path;
• c) processing said plurality of readings from step (b) to produce a line representing the trajectory of the target;
• d) estimating the alignment angle of said sensor relative to the direction of travel of said host vehicle based on said line and said path data;
• and
• e) in subsequent readings of said sensor, combining said estimated alignment angle with the azimuth angle to compensate for any misalignment of said sensor.

Apparatus for determining the angle of any misalignment of a forward-looking sensor mounted on a host vehicle relative to the path of travel of the host vehicle, the sensor producing a set of range and azimuth angle data of a target at each of a series of readings, the host vehicle further including a path prediction unit for producing path data, said apparatus comprising:

• a) first processing means responsive to a plurality of said sensor readings for producing a plurality of location points of said target;
• b) second processing means responsive to said plurality of location points for estimating a trajectory line of the target;
• and
• c) third processing means responsive to said path data and to said trajectory line for estimating said angle of any misalignment.

An automatic azimuth angle correction system for a host vehicle, comprising:

• a) a forward-looking sensor for mounting on the host vehicle, said sensor being operable to make periodic readings of a target and each reading including a set of range and azimuth angle measurements of the target;
• b) a path prediction unit for producing path prediction data of the host vehicle;
• c) first processing means responsive to a plurality of said sensor readings for producing a plurality of location points of said target;
• d) second processing means responsive to said plurality of location points for estimating a trajectory line of the target;
• and
• e) third processing means responsive to said path data and to said trajectory line for estimating any angle of misalignment.