Motion direction determination and application

A mobile device comprising:

• one or more sensors configured to measure acceleration data for the mobile device in each of one or more directions;
• one or more processors;
• and
• a memory storing instructions that, when executed by the one or more processors, implement a motion direction estimation module configured to:
• determine a primary axis of motion of the mobile device based at least in part on the acceleration data;
• and
• determine a motion direction of the mobile device along the primary axis of motion, the determination including:
• fitting the acceleration data, or data derived therefrom, to a bimodal distribution, wherein a first peak of the bimodal distribution corresponds to a first motion direction along the primary axis of motion, and wherein a second peak of the bimodal distribution corresponds to a second motion direction along the primary axis of motion opposite the first motion direction;
• and
• estimating the motion direction of the mobile device relative to a coordinate system based at least in part on the bimodal distribution.

Tangible computer-readable storage media including non-transitory instructions that, when executed by one or more processors, are configured to:

• receive acceleration data for a mobile device in each of one or more directions;
• determine a primary axis of motion of the mobile device based at least in part on the acceleration data;
• and
• determine a motion direction of the mobile device along the primary axis of motion, the determination including:
• fitting the acceleration data, or data derived therefrom, to a bimodal distribution, wherein a first peak of the bimodal distribution corresponds to a first motion direction along the primary axis of motion, and wherein a second peak of the bimodal distribution corresponds to a second motion direction along the primary axis of motion opposite the first motion direction;
• and
• estimating the motion direction of the mobile device relative to a coordinate system based at least in part on the bimodal distribution.

An apparatus comprising:

• means for obtaining acceleration data for the apparatus in each of one or more directions;
• means for determining a primary axis of motion of the apparatus based at least in part on the acceleration data;
• and
• means for determining a motion direction of the apparatus along the primary axis of motion, the means for determining including:
• means for fitting the acceleration data, or data derived therefrom, to a bimodal distribution, wherein a first peak of the bimodal distribution corresponds to a first motion direction along the primary axis of motion, and wherein a second peak of the bimodal distribution corresponds to a second motion direction along the primary axis of motion opposite the first motion direction;
• and
• means for estimating the motion direction of the apparatus relative to a coordinate system based at least in part on the bimodal distribution.