Electronic compass system
First Claim
1. An electronic compass system for a vehicle, comprising:
- a magnetic sensor circuit for sensing three components of the Earth'"'"'s magnetic field vector, and for generating output signals representing the three sensed components;
a pitch and roll sensing circuit for measuring the pitch and roll of the magnetic sensor circuit; and
a processing circuit coupled to said magnetic sensor circuit and said pitch and roll sensing circuit for receiving the output signals, compensating the sensed components for the measured pitch and roll, computing a heading of the vehicle as a function of at least two of the compensated sensed components, and generating a heading signal representing the computed heading.
1 Assignment
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Accused Products
Abstract
An electronic compass system includes a magnetic sensor circuit having at least two sensing elements for sensing perpendicular components of the Earth'"'"'s magnetic field vector. A processing circuit is coupled to the sensor circuit to filter, process, and compute a heading. The processing circuit may determine whether too much noise is present in the output signals received from said magnetic sensor circuit as a function of the relative strength of the Earth'"'"'s magnetic field vector. The magnetic sensor circuit may include three magnetic field sensing elements contained in a common integrated package having a plurality of leads extending therefrom for mounting to a circuit board. The sensing elements need not be perpendicular to each other or parallel or perpendicular with the circuit board. The electronic compass system is particularly well suited for implementation in a vehicle rearview mirror assembly.
217 Citations
21 Claims
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1. An electronic compass system for a vehicle, comprising:
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a magnetic sensor circuit for sensing three components of the Earth'"'"'s magnetic field vector, and for generating output signals representing the three sensed components; a pitch and roll sensing circuit for measuring the pitch and roll of the magnetic sensor circuit; and a processing circuit coupled to said magnetic sensor circuit and said pitch and roll sensing circuit for receiving the output signals, compensating the sensed components for the measured pitch and roll, computing a heading of the vehicle as a function of at least two of the compensated sensed components, and generating a heading signal representing the computed heading. - View Dependent Claims (2, 3)
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4. An electronic compass system for a vehicle, comprising:
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a magnetic sensor circuit for sensing at least two components of the Earth'"'"'s magnetic field vector, and for generating output signals representing the at least two sensed components; and a processing circuit coupled to said magnetic sensor circuit for; receiving the output signals from said magnetic sensor circuit, determining a relative strength of the Earth'"'"'s magnetic field vector, determining whether too much noise is present in the output signals received from said magnetic sensor circuit as a function of the relative strength of the Earth'"'"'s magnetic field vector, if there is not too much noise present in the output signals, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading or a prior heading if too much noise is present in the output signals. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11)
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12. An electronic compass assembly for a vehicle, comprising:
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a circuit board defining a plane corresponding to a mounting surface thereof; a magnetic sensor circuit mounted on said circuit board for sensing at least two components of the Earth'"'"'s magnetic field vector, and for generating output signals representing the at least two sensed components, wherein said magnetic sensor circuit includes at least two magnetic field sensing elements each having an axis of sensitivity, wherein at least one of said magnetic field sensing elements is positioned such that its axis of sensitivity is oriented in one of the following two orientations;
(a) non-perpendicular and non-parallel to the plane of said circuit board, and (b) non-perpendicular to the axis of sensitivity of another one of said at least two magnetic field sensing elements; anda processing circuit coupled to said magnetic sensor circuit for receiving the output signals, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading. - View Dependent Claims (13, 14, 15, 16, 17)
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18. An electronic compass system for a vehicle, comprising:
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a magnetic sensor circuit for sensing at least two components of the Earth'"'"'s magnetic field vector, and for generating output signals representing the at least two sensed components; and a processing circuit coupled to said magnetic sensor circuit for; receiving the output signals from said magnetic sensor circuit, computing a noise level from the output signals received from said magnetic sensor circuit as a function of a root mean square of values derived from the output signals, determining whether too much noise is present in the output signals received from said magnetic sensor circuit if the noise level exceeds a threshold noise level, if there is not too much noise present in the output signals, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading or a prior heading if too much noise is present in the output signals. - View Dependent Claims (19)
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20. An electronic compass system for a vehicle, comprising:
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a magnetic sensor circuit for sensing at least two components of the Earth'"'"'s magnetic field vector, and for generating output signals representing the at least two sensed components; and a processing circuit coupled to said magnetic sensor circuit for; receiving the output signals from said magnetic sensor circuit, computing a noise level from the output signals received from said magnetic sensor circuit as a function of a mean square error of values derived from the output signals, determining whether too much noise is present in the output signals received from said magnetic sensor circuit if the noise level exceeds a threshold noise level, if there is not too much noise present in the output signals, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading or a prior heading if too much noise is present in the output signals. - View Dependent Claims (21)
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Specification