Phase sensitive guidance sensor for wire-following vehicles
First Claim
1. A system for guiding a vehicle along a path defined by a guide wire through which an AC current flows and around which a magnetic field is produced, the system comprising:
- n coils arranged in an array in a direction so as to sense the vertical component of the magnetic field about said wire, with those coils which are on one side of said wire having the vertical component of said field passing those coils in a first direction and the vertical component of said field passing through the remaining coils, which are on the other side of said wire, in an opposite second direction;
control means coupled to said n coils for producing a control signal which is a function of the largest number of coils through which said magnetic field passes in said first direction;
wherein said control means include n bistable means which are respectively associated with said n coils, with the bistable means which are associated with coils through which the vertical component of the magnetic field passes in said first direction being adapted to be driven to a first state, and those bistable means which are associated with coils through which the vertical component of the magnetic field passes in the second direction being adapted to be driven to a second state, said control means including output means for producing said control signal which is related to the largest number of bistable means in said first state.
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Accused Products
Abstract
A guidance sensor for a wire-following vehicle which is phase sensitive, includes an array of coils (C1-C16) positioned to sense the vertical component of a magnetic field (17) produced by the AC current through the guidance wire 15. The outputs of the coils are fed to associated flip flops (FF1-FF16). Flip flops associated with coils, through which flux passes in one direction, e.g. up, are driven to one state, e.g. true, and flip flops associated with coils through which flux passes in the opposite direction, e.g. down, are driven to a false state. The control signal to guide the vehicle to be over the wire is a function of the number of flip flops in the true state. Circuitry (45, 46) is included to prevent flip flops from assuming a wrong state due to noise.
31 Citations
9 Claims
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1. A system for guiding a vehicle along a path defined by a guide wire through which an AC current flows and around which a magnetic field is produced, the system comprising:
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n coils arranged in an array in a direction so as to sense the vertical component of the magnetic field about said wire, with those coils which are on one side of said wire having the vertical component of said field passing those coils in a first direction and the vertical component of said field passing through the remaining coils, which are on the other side of said wire, in an opposite second direction; control means coupled to said n coils for producing a control signal which is a function of the largest number of coils through which said magnetic field passes in said first direction; wherein said control means include n bistable means which are respectively associated with said n coils, with the bistable means which are associated with coils through which the vertical component of the magnetic field passes in said first direction being adapted to be driven to a first state, and those bistable means which are associated with coils through which the vertical component of the magnetic field passes in the second direction being adapted to be driven to a second state, said control means including output means for producing said control signal which is related to the largest number of bistable means in said first state. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A guidance sensor resulting in an alternating magnetic field, the arrangement comprising:
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an array of n coils arranged in a direction perpendicular to the vehicle'"'"'s direction of travel and positioned to sense the vertical component of the magnetic field, whereby during a particular half of each cycle of the magnetic field the vertical component of the magnetic field passes all the coils on one side of the wire in a first direction and passes all coils on the other side of the wire in a second direction; control means coupled to said coils for producing a control signal as a function of the largest number of coils through which said vertical component of the magnetic field passes in said first direction, wherein said control means include n flip flops, each associated with a different one of said n coils, each flip flop being drivable to a first state when its associated coil is one through which the vertical component of the magnetic flux passes in said first direction during the particular half of each cycle, and said control means include means for producing said control signal which is related to the largest number of flip flops in said first state. - View Dependent Claims (8, 9)
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Specification