发明名称 |
Methods and apparatus for low-cost inertial dead-reckoning using context detection |
摘要 |
A method for determining a user bearing, implemented on a portable device programmed to perform the method includes determining with a physical sensor of the portable device, a first geometric orientation of the portable device with respect to gravity at a first time, determining with a magnetic sensor of the portable device, a first sensed magnetic field of the portable device in response to an external magnetic field at the first time, determining with the magnetic sensor of the portable device, a second sensed magnetic field of the portable device in response to the external magnetic field at the second time, and determining with the portable device a bearing of the portable device at the second time in response to the first geometric orientation, the first sensed magnetic field, and the second sensed magnetic field. |
申请公布号 |
US9052203(B2) |
申请公布日期 |
2015.06.09 |
申请号 |
US201313837411 |
申请日期 |
2013.03.15 |
申请人 |
MCUBE, INC. |
发明人 |
Kelly Joseph M. |
分类号 |
G01C21/18;G01C21/16;G01C21/20;G01C21/08 |
主分类号 |
G01C21/18 |
代理机构 |
Kilpatrick Townsend & Stockton LLP |
代理人 |
Kilpatrick Townsend & Stockton LLP |
主权项 |
1. A method for determining a user bearing, implemented on a portable device programmed to perform the method comprising:
determining, with a physical sensor of the portable device, a first geometric orientation of the portable device with respect to gravity at a first time; determining, with a magnetic sensor of the portable device, a first sensed magnetic field of the portable device in response to an external magnetic field at the first time; determining, with the magnetic sensor of the portable device, a second sensed magnetic field of the portable device in response to the external magnetic field at a second time; and determining, with the portable device, a first change in bearing of the portable device at the second time in response to the first geometric orientation, the first sensed magnetic field, and the second sensed magnetic field; wherein determining with the portable device the first change in bearing comprises determining a change in angle about an external vertical axis between a horizontal component of the first sensed magnetic field with respect to an internal horizontal axis and a horizontal component of the second sensed magnetic field with respect to the internal horizontal axis; wherein the horizontal component of the first sense magnetic field being determined from a first measured horizontal component, a local gravity vector, and a direction cosine matrix; and wherein the horizontal component of the second sensed magnetic field being determined from a second measured horizontal component, the local gravity vector, and the direction cosine matrix. |
地址 |
San Jose CA US |