Interruption of vehicle compass calibration in response to vehicle accessory interference
First Claim
1. A vehicle electronic compass system for determining a heading of a vehicle as a function of the earth'"'"'s magnetic field, said vehicle having an associated magnetic signature and an accessory which causes a magnetic disturbance when activated, said system comprising:
- a magnetic sensor for sensing the earth'"'"'s magnetic field and producing sensor output data values;
a processor having a calibration function for calculating a set of calibration parameters from the sensor output data values for calibrating the compass system to account for an influence of the vehicle magnetic signature on the earth'"'"'s magnetic field, and for providing vehicle heading information to a vehicle display; and
means for detecting the activation of said accessory and for disabling said calibration function of the processor so that a calibration calculation is not performed on sensor output data values obtained during activation of said accessory.
1 Assignment
0 Petitions
Accused Products
Abstract
An improved vehicle compass calibration obtains magnetic field data measurements from magnetic field sensors mounted in a vehicle. The magnetic field data measurements are stored in memory and, when a sufficient set of data measurements is stored, a calibration calculation attempt is carried out. When a predetermined vehicle accessory that produces a magnetic disturbance is activated, the storage of magnetic field data in memory is interrupted to disable the ongoing collection of data for use in a subsequent calibration calculation while the accessory remains activated.
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Citations
17 Claims
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1. A vehicle electronic compass system for determining a heading of a vehicle as a function of the earth'"'"'s magnetic field, said vehicle having an associated magnetic signature and an accessory which causes a magnetic disturbance when activated, said system comprising:
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a magnetic sensor for sensing the earth'"'"'s magnetic field and producing sensor output data values;
a processor having a calibration function for calculating a set of calibration parameters from the sensor output data values for calibrating the compass system to account for an influence of the vehicle magnetic signature on the earth'"'"'s magnetic field, and for providing vehicle heading information to a vehicle display; and
means for detecting the activation of said accessory and for disabling said calibration function of the processor so that a calibration calculation is not performed on sensor output data values obtained during activation of said accessory. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An improved calibration system for a vehicle electronic compass for determining a heading of a vehicle as a function of the earth'"'"'s magnetic field, the vehicle having an associated magnetic signature and an accessory which generates a magnetic disturbance when activated, the vehicle electronic compass having a magnetic sensor for sensing the earth'"'"'s magnetic field and producing sensor output data values, and a processor having a calibration function for calculating a set of calibration parameters from the sensor output data values for calibrating the electronic compass to account for an influence of the vehicle magnetic signature on the earth'"'"'s magnetic field, said improvement comprising:
means for detecting the activation of the accessory and for disabling the calibration function of the processor so that a calibration calculation is not performed on sensor output data values obtained during activation of the accessory. - View Dependent Claims (11, 12)
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13. A method for disabling a calibration function of a vehicle electronic compass system including a magnetic sensor mounted in a vehicle, said vehicle having a magnetic signature and an accessory which causes a magnetic disturbance when activated, said compass system providing vehicle direction heading information to a vehicle operator, said method comprising the steps of:
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sensing a magnetic field of the earth by the magnetic sensors and outputting sensed magnetic field data values;
storing said data values in memory locations for use in calculating a set of compass calibration parameters;
detecting activation of the accessory; and
upon said detecting of accessory activation, disabling said storing in the memory locations of magnetic field data values that are output by said sensing step while said accessory remains activated. - View Dependent Claims (14, 15, 16, 17)
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Specification