Non-contact obstacle detection system utilizing ultra sensitive capacitive sensing
First Claim
1. An obstacle detection system comprising:
- a sensing element disposed in proximity to a moveable panel;
a proximity detection circuit in communication with said sensing element, said proximity detection circuit generating a differential output signal reflective of whether a foreign object is in proximity to said element;
a central control module in communication with said sensing element, said central control module determining whether said differential output signal is reflective of a foreign object in proximity to said sensing element, wherein, if said central control module determines that said differential output signal is reflective of a foreign object in proximity to said sensing element, and said moveable panel is moving toward a closed position, then said central control module generates a control output signal to stop said moveable panel from moving toward said closed position;
a first oscillator which generates a first frequency signal, said first frequency signal dependent upon the capacitance of said sensing elements; and
a second oscillator which generates a reference frequency signal, wherein said differential output signal is determined from a comparison between said first frequency signal and said reference frequency signal.
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Abstract
A non-contact obstacle detection system utilizing ultra sensitive capacitive techniques. In an exemplary embodiment, the system includes a sensing element disposed in proximity to a moveable panel and a proximity detection circuit in communication with the sensing element. The proximity detection circuit generates a differential output signal reflective of whether a foreign object is in proximity to the sensing element. In addition, a central control module is in communication with the sensing element. The central control module determines whether the differential output signal is reflective of a foreign object in proximity to the sensing element. If the central control module determines that the differential output signal is reflective of a foreign object in proximity to the sensing element, and the moveable panel is moving toward a closed position, then the central control module generates a control output signal to stop the moveable panel from moving toward the closed position.
75 Citations
30 Claims
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1. An obstacle detection system comprising:
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a sensing element disposed in proximity to a moveable panel;
a proximity detection circuit in communication with said sensing element, said proximity detection circuit generating a differential output signal reflective of whether a foreign object is in proximity to said element;
a central control module in communication with said sensing element, said central control module determining whether said differential output signal is reflective of a foreign object in proximity to said sensing element, wherein, if said central control module determines that said differential output signal is reflective of a foreign object in proximity to said sensing element, and said moveable panel is moving toward a closed position, then said central control module generates a control output signal to stop said moveable panel from moving toward said closed position;
a first oscillator which generates a first frequency signal, said first frequency signal dependent upon the capacitance of said sensing elements; and
a second oscillator which generates a reference frequency signal, wherein said differential output signal is determined from a comparison between said first frequency signal and said reference frequency signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
a coaxial cable coupling said proximity detection circuit and said central control module, said coaxial cable transmitting both a DC power signal and said differential output signal.
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6. The obstacle detection system of claim 5, wherein both said proximity detection circuit and said central control module further comprises a bias “
- T”
apparatus included therewith.
- T”
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7. The obstacle detection system of claim 5, wherein said differential output signal has a frequency range of about 0 HZ to about 15 MHz.
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8. The obstacle detection system of claim 5, wherein said first frequency signal and said reference frequency signal are generated at a frequency of at least 900 MHz.
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9. The obstacle detection system of claim 1, wherein said central control module further comprises:
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a microprocessor; and
software for comparing said differential output signal to a nominal value, said nominal value depending upon a specific position of said moveable panel.
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10. An obstacle detection system comprising:
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at least one sensing element disposed in proximity to a moveable panel;
a proximity detection circuit in communication with each said at least one sensing element, each said proximity detection circuit generating a differential output signal reflective of whether a foreign object is in proximity to said at least one sensing element corresponding thereto;
a central control module in communication with each said sensing element, said central control module determining whether each said differential output signal is reflective of a foreign object in proximity to said at least one sensing element, wherein, if said central control module determines that said differential output signal is reflective of a foreign object in proximity to said at least one sensing element, and said movable panel is moving toward a closed position, then said central control module generates a control output signal to stop said moveable panel from moving toward said closed position;
a first oscillator which generates a first frequency signal, said first frequency signal dependent upon the capacitance of said at least one sensing element corresponding thereto; and
a second oscillator which generates a reference frequency signal, wherein said differential output signal is determined from a comparison between said first frequency signal and said reference frequency signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
a coaxial cable coupling each said proximity detection circuit with said central control module, each said coaxial cable transmitting both a DC power signal and said differential output signal.
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15. The obstacle detection system of claim 14, wherein each said proximity detection circuit and said central control module further comprises a bias “
- T”
apparatus included therewith.
- T”
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16. The obstacle detection system of claim 14, wherein each said
said differential output signal has a frequency range of about 0 Hz to about 15 MHz; - and
said first frequency signal and said reference frequency signal are generated at a frequency of at least 900 MHz.
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17. The obstacle detection system of claim 10, wherein said central control module further comprises:
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a microprocessor;
a multiplexer for selectively passing a selected differential output signal from each differential output signal inputted to said multiplexer; and
software for comparing said selected differential output signal to a nominal value, said nominal value depending upon a specific position of said moveable panel.
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18. The obstacle detection system of claim 10, further comprising:
a power door control module in communication with said central control module, said power door control module controlling the movement of said moveable panel.
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19. An obstacle detection system for a vehicle comprising:
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a moveable panel;
a sensing element disposed in proximity to said moveable panel;
a proximity detection circuit in communication with said sensing element, said proximity detection circuit generating a differential output signal reflective of whether a foreign object is in proximity to said sensing element;
a central control module in communication with said sensing element, said central control module determining whether said differential output signal is reflective of a foreign object in proximity to said sensing element, wherein, if said central control module determines that said differential output signal is reflective of a foreign object in proximity to said sensing element and said moveable panel is moving toward a closed position, then said central control module generates a control output signal to stop said moveable panel from moving toward said closed position;
a first oscillator which generates a first frequency signal, said first frequency signal dependent upon the capacitance of said sensing element; and
a second oscillator which generates a reference frequency signal, wherein said differential output signal is determined from a comparison between said first frequency signal and said reference frequency signal. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
a coaxial cable coupling said proximity detection circuit and said central control module, said coaxial cable transmitting both DC power signal and said differential output signal.
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24. The obstacle detection system of claim 23, wherein both said proximity detection circuit and said central control module further comprises a bias “
- T”
apparatus included therewith.
- T”
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25. The obstacle detection system of claim 23, wherein said differential output signal has a frequency range of about 0 Hz to about 15 MHz.
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26. The obstacle detection system of claim 23, wherein said first frequency signal and said reference frequency signal are generated at a frequency of at least 900 MHz.
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27. The obstacle detection system of claim 19, wherein said central control module further comprises:
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a microprocessor; and
software for comparing said differential output signal to a nominal value, said nominal value depending upon a specific position of said moveable panel.
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28. The obstacle detection system of claim 27, wherein said software further includes a floating variable routine for compensating for environmental changes and structural changes proximate said moveable panel.
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29. The obstacle detection system of claim 28, wherein said floating variable further comprises a global float routine and a position float routine, said global float routine further comprises a global float routine and a position float routine, said global float routine being responsive to environmental changes and said position float routine being responsive to positional change of said moveable panel.
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30. The obstacle detection system of claim 29, wherein said global float routine further includes a global float counter, said global float counter preventing a change in a given global value until such time as said global float counter has reached a determined value.
Specification