Vehicle identification
AssigneeIntelligent Imaging Systems, Inc.
InventorsWolfgang Engler, Brian Heath, Cedar Mah
Life of this patent
Estimating the term…
Abstract
Magnetometers under the road surface detect variations in the vertical and longitudinal horizontal components of the magnetic field over time in response to passing vehicles. A trajectory of these components in the phase space of these field components is regularized to obtain a magnetic signature. Magnetic signatures are compared using cross-correlation over arc length to identify vehicles. Inductance sensors can be used to detect vehicles and help determine the beginning and end of magnetic signatures.
Claims26
A method of vehicle identification, comprising:
- sensing a change in at least two components of a magnetic field at a first location due to movement of a vehicle and producing an event record that includes a vehicle magnetic signature corresponding to the change;
- comparing the vehicle magnetic signature to a database of saved records that include stored magnetic signatures;
- associating the event record with a saved record in the database when a match is obtained between the vehicle magnetic signature and the stored magnetic signature of the saved record;
- and
- performing an action when the match is obtained between the vehicle magnetic signature and the stored magnetic signature;
- wherein the first location is at a road and the stored magnetic signatures are generated by sensing a change in a magnetic field in at least two components at a second location due to movement of vehicles along the road at the second location, the second location being a location past which vehicles travel before reaching the first location.
A method of vehicle identification, comprising:
- sensing a change in at least two components of a magnetic field at a first location due to movement of a vehicle and producing an event record that includes a vehicle magnetic signature corresponding to the change;
- comparing the vehicle magnetic signature to a database of saved records that include stored magnetic signatures;
- associating the event record with a saved record in the database when a match is obtained between the vehicle magnetic signature and the stored magnetic signature of the saved record;
- and
- performing an action when the match is obtained between the vehicle magnetic signature and the stored magnetic signature;
- wherein comparing comprises a cross-correlation performed on a constructed time and process independent measure, and the match is determined by the cross-correlation exceeding a pre-defined threshold.
Dependencies are inferred from the claim text.