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US 6,888,353 B1Granted
Magnetic anomaly homing system and method using magnetic total field scalars
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorRoy Wiegert
Life of this patent
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Abstract
A magnetic anomaly homing system uses an array of magnetic sensors coupled to a non-magnetic platform. The array is defined by a plurality of single-axis subsystems with each one thereof having two magnetic sensors spaced apart from one another. A processor coupled to the magnetic sensors generates a plurality of magnetic total field scalars that can be used to directly home in on a magnetic object from both long and short-range distances to the target. The scalars define guidance control parameters used to steer the platform to align the platforms's direction of motion with the magnetic anomaly.
Claims15
A magnetic anomaly homing system, comprising:
- a non-magnetic platform;
- an array of magnetic sensors coupled to said platform and arranged to define a left half of said array and a right half of said array relative to a direction of motion of said platform, said array defined by a plurality of single-axis subsystems with each one thereof having two of said magnetic sensors spaced apart from one another, said plurality of single-axis subsystems including at least first and second single-axis subsystems arranged parallel to one another in a plane such that said magnetic sensors are disposed at the vertices of a parallelogram with said first single-axis subsystem being part of said left half of said array and said second single-axis subsystem being part of said right half of said array;
- and
- processing means coupled to said magnetic sensors for generating
- (i) a differential total field parameter for each of said left half and said right half of said array, said differential total field parameter for said left half defined as a sum of the total magnetic field due to the presence of a magnetic anomaly at said magnetic sensors associated with said left half, and said differential total field parameter for said right half defined as a sum of the total magnetic field due to the presence of a magnetic anomaly at said magnetic sensors associated with said right half, and
- (ii) a gradient parameter for each of said left half and said right half of said array, said gradient parameter for said left half defined as a sum of total magnetic field gradients for said plurality of single-axis subsystems of said left half, and said gradient parameter for said right half defined as a sum of total magnetic field gradients for said plurality of single-axis subsystems of said right half,
- wherein at least one of (i) said differential total field parameter for said left half and said right half, and (ii) said gradient parameter for said left half and said right half, define guidance control parameters used to steer said platform to align said direction of motion with the magnetic anomaly.
4 more elements
A method of homing in on a magnetic anomaly, comprising the steps of:
- providing an array of magnetic sensors coupled to a non-magnetic platform and arranged to define a left half of said array and a right half of said array relative to a direction of motion of said platform, said array defined by a plurality of single-axis subsystems with each one thereof having two of said magnetic sensors spaced apart from one another, said plurality of single-axis subsystems including at least first and second single-axis subsystems arranged parallel to one another in a plane such that said magnetic sensors are disposed at the vertices of a parallelogram with said first single-axis subsystem being part of said left half of said array and said second single-axis subsystem being part of said right half of said array;
- moving said platform with said array coupled thereto along said direction of motion;
- generating a differential total field parameter for each of said left half and said right half of said array while said platform is moving, said differential total field parameter for said left half defined as a sum of the total magnetic field due to the presence of a magnetic anomaly at said magnetic sensors associated with said left half, and said differential total field parameter for said right half defined as a sum of the total magnetic field due to the presence of a magnetic anomaly at said magnetic sensors associated with said right half;
- generating a gradient parameter for each of said left half and said right half of said array while said platform is moving, said gradient parameter for said left half defined as a sum of total magnetic field gradients for said plurality of single-axis subsystems of said left half, and said gradient parameter for said right half defined as a sum of total magnetic field gradients for said plurality of single-axis subsystems of said right half;
- and
- steering said platform using guidance control parameters to align said direction of motion with the magnetic anomaly, said guidance control parameters defined by at least one of (i) said differential total field parameter for said left half and said right half, and (ii) said gradient parameter for said left half and said right half.
3 more elements
Dependencies are inferred from the claim text.