Vehicle guidance mechanism
First Claim
1. Vehicle guidance means for guiding a vehicle along a surface, said guidance means comprising a guide line which is substantially invisible under ordinary ambient lighting conditions and which contains material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means further comprising:
- radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation;
sensor means mounted in the vehicle and adapted to sense the first frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; and
control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line.
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Accused Products
Abstract
A vehicle guidance mechanism for guiding a vehicle along a surface by means of an invisible guide line containing fluorescent material comprises an ultraviolet lamp that causes the guide line to fluoresce and emit visible light; photocell sensors mounted in the vehicle and adapted to sense the visible radiation and produce an error output signal proportional to the variation of vehicle position from a predetermined lateral position with respect to the guide line; and a control device in the vehicle adapted to steer the vehicle in response to the error signal so as to cause the vehicle to follow the guide line. An automatic contrast control circuit eliminates the effect of background illumination in the output signal and produces a constant closed loop gain with respect to the signal received from the guide line. Modulation circuitry and appropriate filters further reduce the effects of background illumination and improve the reliability and line detecting ability of the guide system. Line detection circuitry is employed to prevent operation of the automatic control device unless the vehicle is tracking a valid guide line.
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Citations
24 Claims
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1. Vehicle guidance means for guiding a vehicle along a surface, said guidance means comprising a guide line which is substantially invisible under ordinary ambient lighting conditions and which contains material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means further comprising:
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radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation; sensor means mounted in the vehicle and adapted to sense the first frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; and control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line.
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2. Vehicle guidance means for guiding a vehicle along a surface, said guidance means including a guide line which is substantially invisible under ordinary ambient lighting conditions and which contains a fluorescent material that emits radiation in a visible frequency range in response to stimulation by radiation in an invisible frequency range, said guidance means further comprising:
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radiation means in the vehicle adapted to direct radiation in an invisible frequency range on the guide line so as to cause the guide line to emit a visible frequency radiation; sensor means mounted in the vehicle and adapted to sense the visible frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; and control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line. - View Dependent Claims (3, 4, 5)
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6. Vehicle guidance means for guiding a vehicle along a surface by means of a guide line containing material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means comprising:
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radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation; sensor means mounted in the vehicle and adapted to sense the first frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line; and modulation circuit means adapted to modulate the second frequency radiation emitted from the radiation means to effectively eliminate the effect the static and fluorescent background illumination from the error output signal, said modulation circuit means modulating the second frequency radiation at a predetermined frequency and including synchronized demodulation means for effectively limiting the error output signal to that portion of the sensor means output signal which is produced by radiation of said predetermined frequency. - View Dependent Claims (7, 8, 9)
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10. Vehicle guidance means for guiding a vehicle along a surface by means of a guide line containing material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means comprising:
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radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation; sensor means mounted in the vehicle and adapted to sense the first frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line; and feed back means adapted to maintain a generally constant ratio between error output signal strength and displacement of the guide line from a predetermined centerline position, regardless of the strength of static or fluorescent background illumination as long as the vehicle is following the guide line and the guide line is brighter than the background when the radiation means is switched on. - View Dependent Claims (11, 12, 13, 14, 15)
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16. Vehicle guidance means for guiding a vehicle along a surface by means of a guide line containing material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means comprising:
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radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation; sensor means mounted in the vehicle and adapted to sense the first frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; the sensor means comprises photocell means adapted to produce separate output signals from at least three positions with respect to the guide line, said positions being to the left, to the right, and centered over the guide line when the guide line is centered with respect to the sensor means; control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line; and line detection means connected to the senosr means and adapted to prevent the vehicle guidance means from operating unless the sensor mechanism is positioned over a guide line, the line detection means being adapted to prevent the initiation of operation of the vehicle guidance means unless the output signal from the center position is greater than the output signals from both the left and right positions. - View Dependent Claims (17, 18, 19, 20)
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21. Vehicle guidance means for guiding a vehicle along a surface by means of a guide line containing material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means comprising:
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radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation; sensor means mounted in the vehicle and adapted to sense the first frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line; feedback means adapted to maintain a generally constant ratio between error output signal strength and displacement of the guide line from a predetermined centerline position, regardless of the strength of static or fluorescent background illumination, as long as the vehicle is following the guide line and the guide line is brighter than the background when the radiation means is switched on, said feedback means producing an error indication when the vehicle is not following the guide line or when the guide line is not brighter than the background by a predetermined amount when the radiation means is switched on; and line detection means responsive to said error indication and adapted to prevent operation of the vehicle guidance means when an error indication is received.
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22. Vehicle guidance means for guiding a vehicle along a surface by means of a guide line containing material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means comprising:
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radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation; sensor means mounted in the vehicle and adapted to sense the first frequency emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; the sensor means comprises photocell means adapted to produce discreet output signals representative of radiation detected at at least three positions with respect to the guide line, two of said positions being to the left and right of the guide line and the third position being such that a predetermined relationship exists between the output representative of the third position and at least one of the other positions when the vehicle guidance means is positioned over the guide line; control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line; and line detection means adapted to prevent the vehicle guidance mechanism from operating unless said predetermined relationship exists. - View Dependent Claims (23)
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24. Vehicle guidance means for guiding a vehicle along a surface by means of a guide line containing material that emits radiation in a first frequency range in response to stimulation by radiation in a second frequency range, said guidance means comprising:
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radiation means in the vehicle adapted to direct radiation in said second frequency range on the guide line so as to cause the guide line to emit said first frequency radiation; sensor means mounted in te vehicle and adapted to sense the first frequency radiation emitted by the guide line and in response thereto to generate an error output signal representative of the variation of the vehicle position from a predetermined lateral position with respect to the guide line; means for rendering said sensor means substantially nonresponsive to reflected radiation in the second frequency range; and control means in the vehicle adapted to steer the vehicle in response to the error signal generated by the sensor means so as to maintain the vehicle in said predetermined lateral position with respect to the guide line as the vehicle moves along the guide line.
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Specification