Magnetometer bias and anomaly detector
AssigneeInvenSense, Inc.
InventorWilliam Kerry Keal
Life of this patent
Estimating the term…
Abstract
The computer implemented method, system or computer program product comprises collecting magnetometer data from the device; and calculating a center of a shape of the magnetometer data as a result of minimization. The minimization of calculating the center of the shape further comprises calculating a plurality of running sums of the magnetometer data; storing the plurality of running sums; storing a count of the number of terms in each of the running sums; and calculating the center of the shape and setting the estimated magnetometer bias to the center of the shape. The radius of the sphere is calculated to ensure accuracy in the estimator of the magnetometer bias.
Claims30
A computer implemented method of estimating a magnetometer bias for a device comprising:
- collecting magnetometer data from the device;
- and calculating using a computer a center of a shape of the magnetometer data as a result of minimization;
- wherein the magnetometer data is represented by data points, wherein the minimization is a derivative of a sum of weighted distances of pairs of data points, wherein each of the weighted distances is weighted based upon how far apart the pair of points are from each other;
- wherein the minimization of calculating the center of the shape further comprises:
- calculating a plurality of running sums of the magnetometer data;
- storing the plurality of running sums;
- storing a count of the number of terms in each of the running sums;
- and calculating the center of the shape and setting the estimated magnetometer bias to the center of the shape.
A device comprising:
- a processor;
- a magnetometer for providing magnetometer data;
- and a memory coupled to the processor;
- wherein the memory receives the magnetometer data;
- wherein the memory includes an algorithm for estimating the bias of the magnetometer data;
- wherein the processor executes the algorithm to perform the following operations;
- calculating a center of a shape of the magnetometer data as a result of minimization;
- wherein the magnetometer data is represented by data points, wherein the minimization is a derivative of a sum of weighted distances of pairs of data points, wherein each of the weighted distances is weighted based upon how far apart the pairs of data points are from each other;
- wherein the minimization of calculating the center of the shape further comprises calculating a plurality of running sums of the magnetometer data;
- storing the plurality of running sums;
- storing a count of the number of terms in each of the running sums;
- and calculating the center of the shape and setting the estimated magnetometer bias to the center of the shape.
A non-transitory computer program product including a computer readable medium to be executed on a computer, the computer readable medium for performing the following operations comprising:
- collecting magnetometer data from the device;
- and calculating a center of a shape of the magnetometer data as a result of minimization;
- wherein the magnetometer data is represented by data points, wherein the minimization is a derivative of a sum of weighted distances of pairs of data points, wherein each of the weighted distances is weighted based upon how far apart the pairs of data points are from each other;
- wherein the minimization of calculating of a center of an the shape further comprises:
- calculating a plurality of running sums of the magnetometer data;
- storing the plurality of running sums;
- storing a count of the number of terms of running sums;
- and calculating the bias from the stored running sums when the count of the plurality of running sums is less than a predetermined threshold.
Dependencies are inferred from the claim text.