Electronic compass and related heading filter method
First Claim
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1. A method comprising:
- determining a first parameter based at least upon a heading magnitude (Mhi);
determining a second parameter based at least upon an angle heading (Ahi);
if the first parameter is greater than a positive filter threshold or less than a negative filter threshold, setting a timer to a predetermined timer value;
if a current value of the timer is greater than zero, determining a filtered heading based at least partially upon the current value of the timer; and
if the current value of the timer is equal to zero, determining the filtered heading based at least partially upon the second parameter and a filter algorithm selected on a basis of a magnitude of the second parameter.
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Abstract
A method for determining a compass heading in a manner that reduces the influence of magnetic noise. The methodology can evaluate changes between various parameters, such as a prior magnetic field parameter and a current magnetic field parameter and/or a prior compass heading parameter and a current compass heading to select an algorithm for use in calculating a new compass heading.
7 Citations
22 Claims
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1. A method comprising:
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determining a first parameter based at least upon a heading magnitude (Mhi); determining a second parameter based at least upon an angle heading (Ahi); if the first parameter is greater than a positive filter threshold or less than a negative filter threshold, setting a timer to a predetermined timer value; if a current value of the timer is greater than zero, determining a filtered heading based at least partially upon the current value of the timer; and if the current value of the timer is equal to zero, determining the filtered heading based at least partially upon the second parameter and a filter algorithm selected on a basis of a magnitude of the second parameter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for determining a compass heading comprising:
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determining a difference between an angle parameter of a magnetic field vector and a prior value of the compass heading; and selecting an algorithm for determining the compass heading based upon a difference between the angle parameter of the magnetic field vector and the prior value of the compass heading. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A method comprising:
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determining a magnitude of a magnetic field vector; and determining a filtered compass heading at least partially based upon the magnitude of the magnetic field vector; wherein determining the filtered compass heading further comprises; setting a timer to a predetermined value if the magnitude of the predetermined variable is out-of-bounds; and selecting an algorithm for calculating the filtered compass heading based on a value of the timer. - View Dependent Claims (20)
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21. A method comprising:
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determining a magnitude of a magnetic field vector; and determining a filtered compass heading at least partially based upon the magnitude of the magnetic field vector; wherein determining the filtered compass heading comprises determining a compensation coefficient based at least partially on the magnetic field vector. - View Dependent Claims (22)
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Specification