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
0 Petitions
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.
117 Citations
106 Claims
-
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. - View Dependent Claims (2, 3)
-
-
4. An electronic compass system for a vehicle, comprising:
-
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)
-
-
12. An electronic compass assembly for a vehicle, comprising:
-
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; and
a 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)
-
-
18. A rearview mirror assembly for a vehicle, comprising:
-
a mirror mounting structure configured to mounting to a vehicle and having a mirror housing;
a mirror mounted in said mirror housing;
a circuit board carried by said mirror mounting structure;
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 three magnetic field sensing elements contained in a common integrated package having a plurality of leads extending therefrom for mounting to said circuit board; and
a processing circuit coupled to said magnetic sensor circuit for receiving the output signals from said magnetic sensor circuit, 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 (19)
-
-
20. An electronic compass subassembly for a vehicle, comprising:
-
a circuit board including a connector for connecting an electrical component; and
a processing circuit mounted on said on said circuit board and electrically coupled to said connector for communicating with the electrical component, wherein said processing circuit is coupled to a magnetic sensor circuit for receiving output signals representing at least two components of the Earth'"'"'s magnetic field vector, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading, wherein said processing circuit is configured to communicate using at least two different signal formats associated with different types of electronic components, and wherein a particular signal format used by said processing circuit to communicate with the electrical component connected to said connector is selectable. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
-
-
29. An electronic compass system for a vehicle, comprising:
-
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;
a processing circuit coupled to said magnetic sensor circuit for receiving the output signals from said magnetic sensor circuit, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading; and
a display coupled to said processing circuit for receiving said heading signal and displaying the computed heading, said display further configured to display a geographical representation of at least one geographic region and a geographic magnetic variance zone within the geographic region for which the compass is presently calibrated. - View Dependent Claims (30, 31, 32, 33)
-
-
34. An electronic compass system for a vehicle, comprising:
-
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;
a processing circuit coupled to said magnetic sensor circuit for receiving the output signals from said magnetic sensor circuit, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading; and
a display coupled to said processing circuit for receiving said heading signal and displaying the computed heading, said display further configured to display a time zone for which the compass is presently calibrated. - View Dependent Claims (35, 36, 37, 38, 39)
-
-
40. An electronic compass system for a vehicle, comprising:
-
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 heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading, wherein said processing circuit is coupled to a vehicle electrical component to receive an indication of a time zone in which the vehicle is presently traveling, said processing circuit compensates the heading computation as a function of geographic magnetic variance for the time zone in which the vehicle is presently traveling. - View Dependent Claims (41, 42, 43)
-
-
44. An electronic compass system for a vehicle, comprising:
-
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 heading of the vehicle as a function of the sensed components, generating a heading signal representing the computed heading, storing historical samples of the computed heading at periodic intervals, analyzing the stored historical samples to determine at which four sets of values of the sensed components that the vehicle travels most frequently, computing a variance of the four sets of values of the sensed components that the vehicle travels most frequently from the four sets of values of the sensed components that the processing circuit had identified as corresponding to headings of north, south, east, and west, and compensating the heading computation as a function of the computed variance. - View Dependent Claims (45, 46, 47, 48, 49)
-
-
50. An electronic compass system for a vehicle, comprising:
-
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 (51)
-
-
52. An electronic compass system for a vehicle, comprising:
-
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 (53)
-
-
54. In a vehicle having a conductive glass windshield with an electrically conductive material incorporated therein and an electronic compass system having a magnetic sensor circuit located in proximity to the conductive glass windshield, the magnetic sensor circuit senses at least two components of the Earth'"'"'s magnetic field vector and generates output signals representing the at least two sensed components, an improvement comprising:
-
a processing circuit coupled to the magnetic sensor circuit for sampling the output signals from the magnetic sensor circuit, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading; and
compensating means for compensating for the effect of an electric field caused by a conductive glass windshield on the magnetic field sensed by the magnetic sensor circuit. - View Dependent Claims (55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74)
-
-
75. A method of mounting magnetic sensing elements on a circuit board, the method comprising:
-
mounting a first magnetic sensing element on a first portion of the circuit board;
mounting a second magnetic sensing element on a second portion of the circuit board;
bending the second portion of the circuit board to reorient the second magnetic sensing element relative to the first magnetic sensing element; and
securing the second portion of the circuit board relative to the first portion of the circuit board to retain the reoriented positions of the first and second magnetic sensing elements. - View Dependent Claims (76, 77, 78, 79)
-
-
80. An electronic compass system for a vehicle, comprising:
-
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 heading of the vehicle as a function of the sensed components, generating a heading signal representing the computed heading, monitoring the output signals to identify changes in vehicle heading representing a vehicle turn of about 90 degrees, storing the sensed components for those vehicle headings traveled immediately before and after any vehicle turn of about 90 degrees, computing a variance of the stored sensed components from the four sets of values of the sensed components that the processing circuit had identified as corresponding to headings of north, south, east, and west, and compensating the heading computation as a function of the computed variance. - View Dependent Claims (81, 82)
-
-
83. An electronic compass system for a vehicle, comprising:
-
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 heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading, wherein said processing circuit determines in which of a plurality of geographic zones the vehicle is presently traveling, and compensates the heading computation as a function of geographic magnetic variance for the geographic zone in which the vehicle is presently traveling, wherein said processing circuit determines in which geographic zone the vehicle is currently traveling by monitoring for changes in vehicle location relative to the plurality of geographic zones by monitoring vehicle headings and time of travel at each vehicle heading.
-
-
84. An electronic compass system for use in a vehicle having vehicle equipment consisting of one of a convertible top and sunroof, said electronic compass system comprising:
-
a magnetic sensor circuit for sensing at least two components of the Earth'"'"'s magnetic field vector and generating output signals representing the at least two sensed components;
a processing circuit coupled to the magnetic sensor circuit for sampling the output signals from the magnetic sensor circuit, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading; and
compensating means for compensating for the effect of a change in the opened or closed state of the vehicle equipment on the magnetic field sensed by the magnetic sensor circuit. - View Dependent Claims (85, 86, 87, 88, 89, 90, 91, 92, 93, 94)
-
-
95. An electronic compass system for use in a vehicle having at least one vehicle accessory capable of adversely effecting the operation of the compass system, said electronic compass system comprising:
-
a magnetic sensor circuit for sensing at least two components of the Earth'"'"'s magnetic field vector and generating output signals representing the at least two sensed components;
a processing circuit coupled to the magnetic sensor circuit for sampling the output signals from the magnetic sensor circuit, computing a heading of the vehicle as a function of the sensed components, and generating a heading signal representing the computed heading; and
wherein said processing circuit immediately compensates for the effect of the vehicle accessory on the magnetic field sensed by the magnetic sensor circuit upon detection of the effect of the vehicle accessory on the magnetic field without requiring a signal from the vehicle accessory. - View Dependent Claims (96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106)
-
Specification