Using clustering techniques to improve magnetometer bias estimation
First Claim
Patent Images
1. A computer-implemented method, comprising:
- receiving, by a mobile device, a reading from a magnetometer of the mobile device;
selecting, by a processor of the mobile device, a cluster from a plurality of clusters of bias offsets, wherein;
each of the clusters includes a plurality of bias offsets including a representative bias offset,the plurality of clusters are generated by clustering on bias vectors calculated from previous magnetometer readings, andselecting the cluster from the clusters includes matching the reading from the magnetometer to a respective set of one or more mean values of each of the clusters and identifying the cluster from the clusters according to a respective set of one or more threshold values;
estimating, by the processor, a current external magnetic field based on the reading and the representative bias offset for the selected cluster; and
determining, by the processor, a heading for the mobile device using the estimated current external field.
2 Assignments
0 Petitions
Accused Products
Abstract
In some implementations, a computer-implemented method includes receiving a reading from a magnetometer of a mobile device. A cluster from a plurality of clusters of bias offsets generated from previously-calibrated readings is selected. The selected cluster has a representative bias offset, a mean of magnitudes in the selected cluster, and a magnitude threshold. An external magnetic field is estimated based on the reading and the representative bias offset for the selected cluster. Whether a magnitude of the estimated external field is within a magnitude range defined by the mean magnitude and the mean magnitude plus the magnitude threshold is determined.
-
Citations
26 Claims
-
1. A computer-implemented method, comprising:
-
receiving, by a mobile device, a reading from a magnetometer of the mobile device; selecting, by a processor of the mobile device, a cluster from a plurality of clusters of bias offsets, wherein; each of the clusters includes a plurality of bias offsets including a representative bias offset, the plurality of clusters are generated by clustering on bias vectors calculated from previous magnetometer readings, and selecting the cluster from the clusters includes matching the reading from the magnetometer to a respective set of one or more mean values of each of the clusters and identifying the cluster from the clusters according to a respective set of one or more threshold values; estimating, by the processor, a current external magnetic field based on the reading and the representative bias offset for the selected cluster; and determining, by the processor, a heading for the mobile device using the estimated current external field. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A computer program product encoded on a tangible, non-transitory storage medium, the product comprising computer readable instructions for causing one or more processors to perform operations comprising:
-
receiving, by a mobile device, a reading from a magnetometer of the mobile device; selecting, by a processor of the mobile device, a cluster from a plurality of clusters of bias offsets, wherein; each of the clusters includes a plurality of bias offsets including a representative bias offset, the plurality of clusters are generated by clustering on bias vectors calculated from previous magnetometer readings, and selecting the cluster from the clusters includes matching the reading from the magnetometer to a respective set of one or more mean values of each of the clusters and identifying the cluster from the clusters according to a respective set of one or more threshold values; estimating, by the processor, a current external magnetic field based on the reading and a representative bias offset for the selected cluster; and determining, by the processor, a heading for the mobile device using the estimated current external field. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
-
17. A mobile device, comprising:
-
a magnetometer; memory configured to a plurality of clusters of bias offsets generated from previously-calibrated readings; and one or more processors configured to perform operations comprising; receiving a reading from the magnetometer; selecting a cluster from a plurality of clusters of bias offsets, wherein; each of the clusters includes a plurality of bias offsets including a representative bias offset, the plurality of clusters are generated by clustering on bias vectors calculated from previous magnetometer readings, and selecting the cluster from the clusters includes matching the reading from the magnetometer to a respective set of one or more mean values of each of the clusters and identifying the cluster from the clusters according to a respective set of one or more threshold values; estimating a current external magnetic field based on the reading and the representative bias offset for the selected cluster; and determining a heading for the mobile device using the estimated current external field. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
-
Specification