Methods and apparatus for obtaining positional information

Apparatus for obtaining positional information relating to an object, comprising:

• a warning zone definition stage for defining a warning zone of arbitrary shape within a detection field of the apparatus;
• a transmitter for transmitting a probe signal towards an object, the transmitter comprising a transmitting element;
• a receiver for receiving, at a plurality of spaced apart locations, the probe signal as returned by the object, the receiver comprising a plurality of receiving elements forming an antenna array;
• a detector, coupled to the receiver, for detecting the relative timing of the returned probe signals as received at the plurality of spaced apart locations, thereby to determine the position of the object in the detection field, regardless of whether the object is within or outside the warning zone located within the detection field;
• and
• a discrimination stage for determining whether the object is within the warning zone by comparison of the determined position with the warning zone;
• wherein the warning zone is defined as a three-dimensional region within the detection field, and the warning zone is contained within and is smaller than the detection field.

Apparatus for obtaining positional information relating to an object, the apparatus being adapted to be located on a vehicle and comprising:

• a warning zone definition stage for defining a warning zone of arbitrary shape within a detection field of the apparatus;
• an object location stage for determining the position of a detected object in the detection field of the apparatus, regardless of whether the object is within or outside the warning zone;
• and
• a discrimination stage for determining whether the detected object is within the warning zone by comparison of the determined position with the warning zone;
• wherein the object location stage is located in a single housing or on a common substrate, the single housing or common substrate being adapted to be located within a bumper of the vehicle;
• and
• the warning zone definition stage is operable to define the warning zone as a three-dimensional region within the detection field, contained within and smaller than the detection field, and at least partially surrounding the vehicle when the apparatus is located on the vehicle.

Apparatus for obtaining positional information relating to an object, comprising:

• a warning zone definition stage for defining a warning zone of arbitrary shape within a detection field of the apparatus;
• an object location stage for determining the position of a detected object in the detection field, regardless of whether the object is within or outside the warning zone;
• and
• a discrimination stage for determining whether the detected object is within or outside the warning zone by comparison of the determined position with the warning zone;
• wherein the warning zone is a three-dimensional region within and smaller than the detection field, and is within a passenger compartment of the vehicle;
• and
• the apparatus is operable, in dependence on whether the object is within the warning zone, to at least one of control deployment of an air bag and detect an intruder and detect movement of a driver of the vehicle.

A method for obtaining positional information relating to an object, comprising:

• defining a warning zone of arbitrary shape within a detection field of the apparatus;
• determining the position of a detected object in the detection field, regardless of whether the object is within or outside the warning zone;
• and
• determining whether the detected object is within the warning zone by comparison of the determined position with the warning zone;
• wherein the warning zone is defined as a three-dimensional region within the detection field, and the warning zone is contained within and is smaller than the detection field.