Vehicle in-lane positional indication/control by phase detection of RF signals induced in completely-passive resonant-loop circuits buried along a road lane
First Claim
1. A method of determining a vehicle'"'"'s position on road lane comprising:
- positioning a multiplicity of passive resonant circuits along a road lane;
inductively coupling a first electromagnetic field from a first loop means in the vehicle as the vehicle proceeds along the road lane so that electromagnetic energy is inductively coupled from this first loop means into one or more of the multiplicity of resonant circuits as are then proximate to the vehicle, causing these one or more resonant circuits to themselves produce another, second, electromagnetic field; and
detecting, in another, second, loop means in the vehicle as the vehicle proceeds along the road lane, a phase and a polarity of the second electromagnetic field relative to a phase and a polarity of the first electromagnetic field as an indication of the vehicle'"'"'s position upon the road land relative to those one or more of the multiplicity of resonant circuits into which energy was inductively coupled.
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Accused Products
Abstract
A vehicle'"'"'s position is determined, normally within ±0.37 inches, relative to an imaginary center line of a road lane along which are buried, normally about every 13 feet, completely passive resonant circuits, normally each a simple, inexpensive and durable 1-turn 11.5" diameter shallow loop of #12 copper wire in series with a proper capacitor, nominally 10 nanofarads, for resonance. In-lane positional determination is in and by a phase detection circuit, and process. A low-power r.f. electromagnetic field, normally 1.9432 MHz, is maintained in a (i) vertically- or (ii) horizontally-oriented first loop, normally a 6-turn 6-inch coil. Resonance is electromagnetically induced in nearby road coils; radiated fields are not involved. The induced r.f. field is itself then detected in a another, second, loop means within the vehicle. This second loop means may be a (i) horizontally-oriented 6-turn 6-inch coil, or, alternatively and for improved linearity of detection about lane center, (ii) two coils that are in the same plane, orthogonal relative to the first loop, and at any arbitrary angle (other than 90°) relative to the first loop. As the vehicle proceeds down the highway lane a position detector circuit provides an output error signal voltage--equivalent to the phase difference between the maintained and the detected electromagnetic fields--that is (nominally) positive if the vehicle is on the left side of the road loops, or negative if the vehicle is on the right side of the road loops. When the vehicle reaches the center of the lane then the positional error voltage (i.e., the phase difference) nulls out. This error voltage is used to provide the driver with a "steer left" or "steer right" indication, normally in and by a meter. In expansion of the system to fully-automated lane-holding control, the developed positional error voltage signal is used to control the steering of the vehicle.
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Citations
26 Claims
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1. A method of determining a vehicle'"'"'s position on road lane comprising:
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positioning a multiplicity of passive resonant circuits along a road lane; inductively coupling a first electromagnetic field from a first loop means in the vehicle as the vehicle proceeds along the road lane so that electromagnetic energy is inductively coupled from this first loop means into one or more of the multiplicity of resonant circuits as are then proximate to the vehicle, causing these one or more resonant circuits to themselves produce another, second, electromagnetic field; and detecting, in another, second, loop means in the vehicle as the vehicle proceeds along the road lane, a phase and a polarity of the second electromagnetic field relative to a phase and a polarity of the first electromagnetic field as an indication of the vehicle'"'"'s position upon the road land relative to those one or more of the multiplicity of resonant circuits into which energy was inductively coupled. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for determining a vehicle'"'"'s position on a road lane comprising:
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a multiplicity of passive resonant circuits positioned along a road lane; electromagnetic field generating means in the vehicle for generating an electromagnetic field at the vehicle as the vehicle proceeds along the road lane so that energy of this electromagnetic field is inductively coupled into one or more of the multiplicity of resonant circuits as are then proximate to the vehicle; detector means in the vehicle for detecting electromagnetic energy that is inductively coupled back from those one or more of the multiplicity of resonant circuits into which electromagnetic energy had first been coupled as the vehicle proceeds along the road lane; and phase-and-polarity means for comparing a phase and polarity of the generated electromagnetic field to a phase and polarity of the detected electromagnetic field to determine whether the detector means in the vehicle is to the left, or central, or to the right, of a then-proximate resonant circuit. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 22, 23, 24)
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20. A system for determining a vehicle'"'"'s position on a road lane comprising:
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a multiplicity of passive resonant circuits positioned along a road lane at least one of which includes a conductive loop, in electrical series with a capacitor; an electromagnetic field generating means in the vehicle for generating an electromagnetic field at the vehicle as the vehicle proceeds along the road lane so the energy of the electromagnetic field is inductively coupled into one or more of the multiplicity of resonant circuits as are then proximate to the vehicle, the electromagnetic field generating means including a first loop; a detector means in the vehicle for detecting electromagnetic energy that is inductively coupled back from those one or more of the multiplicity of resonant circuits into which electromagnetic energy had first been coupled as the vehicle proceeds along the road lane the detector means including two second loops (i) in the same plane, (ii) orthogonal relative to the first loop, and (iii) and at any arbitrary angle, other than 90°
, relative to the conductive loop, andphase-and-polarity means for comparing the phase and polarity of the generated electromagnetic field to a phase and polarity of the detected electromagnetic field to determine whether the detector means in the vehicle is to the left, or central, or right of a then-proximate resonant circuit. - View Dependent Claims (21)
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25. A relative-position detection system for a vehicle for determining the vehicle'"'"'s left-right relative position:
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a passive resonant circuit positioned as a reference; an electromagnetic field generating means in the vehicle for generating an electromagnetic field at the vehicle, the energy of this electromagnetic field being inductively coupled in the near field into the passive resonant circuit; a positionally-sensitive detector means in the vehicle for detecting an electromagnetic field that is inductively induced in the passive resonant circuit so as to produce a signal of a first polarity if the detector means is positionally to the left of the passive resonant circuit, and of an opposite, second, polarity if the detector means is positionally to the right of the passive resonant circuit.
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26. A relative-position detection system for a vehicle for determining the vehicle'"'"'s left-right relative position:
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a passive resonant electrical circuit positioned as a reference; an electromagnetic filed generating means in the vehicle for generating an electromagnetic field at the vehicle, the energy of this electromagnetic field being coupled in the near field into the resonant circuit; a positionally-sensitive detector means in the vehicle for detecting an electromagnetic field that is inductively induced in the passive resonant circuit so as to produce a sisal of the first polarity if the detector means is positionally to the left of the passive resonant circuit, and of an opposite, second, polarity if the detector means is positionally to the right of the passive resonant circuit, the positionally-sensitive detector means including a loop in which a voltage is induced by the electromagnetic field that is itself inductively induced into the passive resonant circuit; and a phase-comparison means for comparing a phase of the generated electromagnetic field to a phase of the detected voltage to determine whether the detector means in the vehicle is positionally to the left, or to the right, of the passive resonant circuit.
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Specification