Accelerometer-aided gyroscope
First Claim
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1. A system, comprising:
- a gyroscope configured to produce a gyroscope signal;
a low-pass filter unit coupled to said gyroscope and having a configurable bandwidth, said filter unit configured to low-pass filter the gyroscope signal; and
control logic coupled to said filter unit and configured to alter the bandwidth of the low-pass filter unit based on an accelerometer signal by;
computing a metric based on the accelerometer signal to remove an acceleration due to gravity;
comparing of the metric to a threshold;
setting a bandwidth of the low-pass filter unit based on an accelerometer signal and the computed metric;
wherein computing the metric comprising;
squaring the acceleration signal for each axis;
summing the squares of the acceleration signals;
taking a square root of the sum; and
subtracting a gravitational constant; and
,wherein computing the metric M uses the equation
M=√
{square root over (var(Ax)+var(Ay)+var(Az))}{square root over (var(Ax)+var(Ay)+var(Az))}{square root over (var(Ax)+var(Ay)+var(Az))}where “
var( )”
is a variance computed over a predetermined number of samples.
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Abstract
A system comprises a gyroscope configured to produce a gyroscope signal, an accelerometer configured to produce an accelerometer signal, and a filter unit coupled to the gyroscope and having a configurable bandwidth. The filter unit configured to filter the gyroscope signal. The system also comprises control logic that is configured to alter the bandwidth of the filter unit based on the accelerometer signal.
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7 Claims
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1. A system, comprising:
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a gyroscope configured to produce a gyroscope signal; a low-pass filter unit coupled to said gyroscope and having a configurable bandwidth, said filter unit configured to low-pass filter the gyroscope signal; and control logic coupled to said filter unit and configured to alter the bandwidth of the low-pass filter unit based on an accelerometer signal by; computing a metric based on the accelerometer signal to remove an acceleration due to gravity; comparing of the metric to a threshold; setting a bandwidth of the low-pass filter unit based on an accelerometer signal and the computed metric; wherein computing the metric comprising; squaring the acceleration signal for each axis; summing the squares of the acceleration signals; taking a square root of the sum; and subtracting a gravitational constant; and
,wherein computing the metric M uses the equation
M=√
{square root over (var(Ax)+var(Ay)+var(Az))}{square root over (var(Ax)+var(Ay)+var(Az))}{square root over (var(Ax)+var(Ay)+var(Az))}where “
var( )”
is a variance computed over a predetermined number of samples. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification