Wireless tire pressure sensing system
First Claim
1. A wireless tire pressure sensing system for an aircraft, said system comprising:
- dual resonant circuits mounted to a wheel of the aircraft, one resonant circuit comprising;
a first variable capacitance sensor for monitoring the pressure of a tire mounted to said wheel;
and a first wire loop of a first predetermined inductance coupled to said first variable capacitance sensor, and the other resonant circuit comprising;
a second variable capacitance sensor operative as a reference to said first variable capacitance sensor; and
a second wire loop of a second predetermined inductance coupled to said second variable capacitance sensor;
an interrogating circuit magnetically coupleable to said dual resonant circuits and operative to induce magnetically a variable frequency current in the dual resonant circuits, said one resonant circuit responding to said induced current with an E-field signal at a first resonant frequency commensurate with the capacitance of said first variable capacitance sensor, and said other resonant circuit responding to said induced current with an F-field signal at a second resonant frequency commensurate with the capacitance of said second variable capacitance sensor;
a receiving circuit F-field coupleable to said dual resonant circuits and operative to receive said E-field signals at said first and second resonant frequencies and to generate first and second signals representative thereof; and
a processing circuit coupled to said receiving circuit for processing said first and second signals to generate a compensated pressure reading of said tire.
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Accused Products
Abstract
A wireless tire pressure sensing system for an aircraft comprises: dual resonant circuits mounted to a wheel of the aircraft, each resonant circuit comprising: a variable capacitance sensor and a wire loop of a predetermined inductance coupled thereto, one capacitance sensor for monitoring the pressure of a tire mounted to the wheel, and the other capacitance sensor operative as a reference to the one capacitance sensor; an interrogating circuit magnetically coupleable to the dual resonant circuits and operative to induce magnetically a variable frequency current in the dual resonant circuits, the one resonant circuit responding to the induced current with an E-field signal at a first resonant frequency commensurate with the capacitance of the one sensor, and the other resonant circuit responding to the induced current with an E-field signal at a second resonant frequency commensurate with the capacitance of the other sensor; a receiving circuit E-field coupleable to the dual resonant circuits and operative to receive the E-field signals at the first and second resonant frequencies and to generate first and second signals representative thereof; and a processing circuit coupled to the receiving circuit for processing the first and second signals to generate a compensated pressure reading of the tire. The pressure sensing system may be modified to provide and/or include wheel speed sensing.
51 Citations
39 Claims
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1. A wireless tire pressure sensing system for an aircraft, said system comprising:
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dual resonant circuits mounted to a wheel of the aircraft, one resonant circuit comprising;
a first variable capacitance sensor for monitoring the pressure of a tire mounted to said wheel;and a first wire loop of a first predetermined inductance coupled to said first variable capacitance sensor, and the other resonant circuit comprising;
a second variable capacitance sensor operative as a reference to said first variable capacitance sensor; and
a second wire loop of a second predetermined inductance coupled to said second variable capacitance sensor;an interrogating circuit magnetically coupleable to said dual resonant circuits and operative to induce magnetically a variable frequency current in the dual resonant circuits, said one resonant circuit responding to said induced current with an E-field signal at a first resonant frequency commensurate with the capacitance of said first variable capacitance sensor, and said other resonant circuit responding to said induced current with an F-field signal at a second resonant frequency commensurate with the capacitance of said second variable capacitance sensor; a receiving circuit F-field coupleable to said dual resonant circuits and operative to receive said E-field signals at said first and second resonant frequencies and to generate first and second signals representative thereof; and a processing circuit coupled to said receiving circuit for processing said first and second signals to generate a compensated pressure reading of said tire. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method of wirelessly measuring pressure of a tire of an aircraft;
- said method comprising the steps of;
mounting first and second resonant circuits to a wheel of the aircraft to which the tire is mounted; monitoring tire pressure with said first resonant circuit; using said-second resonant circuit as a-reference to said first resonant circuit; generating a variable frequency signal; magnetically coupling the variable frequency signal to the first and second resonant circuits; inducing first and second resonant frequencies in the first and second resonant circuits, respectively, by the magnetically coupled variable frequency signal, said first resonant frequency representative of an uncompensated pressure reading and said second resonant frequency signal representative of a compensation reading; E-field coupling the first and second resonant frequencies from the first and second resonant circuits to a receiver circuit; and generating a compensated pressure reading from the E-field coupled first and second resonant frequencies. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
- said method comprising the steps of;
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31. A wireless tire pressure sensing system for an aircraft, said system comprising:
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a resonant circuit mounted to a wheel of the aircraft, said resonant circuit comprising;
a variable capacitance sensor for monitoring the pressure of a tire mounted to said wheel; and
a wire loop of a predetermined inductance coupled to said variable capacitance sensor;an interrogating circuit magnetically coupleable to said resonant circuit and operative to induce magnetically a variable frequency current in the resonant circuit, said resonant circuit responding to said induced current with an E-field signal at a resonant frequency commensurate with the capacitance of said variable capacitance sensor; a receiving circuit comprising;
an E-field antenna E-field coupleable to said resonant circuit and operative to receive E-field signals solely within an E-field null of the magnetic coupling of the interrogating circuit, said E-field signals including the E-field signal at said resonant frequency; and
a sensing circuit coupled to the E-field antenna for converting said received resonant frequency E-field signal into a signal representative thereof; anda processing circuit coupled to said receiving circuit for processing said converted signal to generate a pressure reading of said tire. - View Dependent Claims (32, 33)
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34. A method of wirelessly measuring pressure of a tire of an aircraft;
- said method comprising the steps of;
mounting a resonant circuit to a wheel of the aircraft to which the tire is mounted; monitoring tire pressure with said resonant circuit; generating a variable frequency signal; magnetically coupling the variable frequency signal to the resonant circuit; inducing a resonant frequency in the resonant circuit by the magnetically coupled variable frequency signal, said resonant frequency representative of a pressure reading; E-field coupling the resonant frequency from the resonant circuit to an E-field antenna, said E-field coupling being solely within the E-field null of the magnetic coupling to the resonant circuit; and generating a pressure, reading from the E-field coupled resonant frequency of said E-field antenna. - View Dependent Claims (35, 36, 37, 38, 39)
- said method comprising the steps of;
Specification