Device orientation initialization

A computer program product comprising code stored in a non-transitory computer-readable storage medium, the code comprising:

• code to perform, by a device, via one or more sensors of the device, one or more sensor measurements, the device being within or coupled to a vehicle in motion;
• code to determine an acceleration of the device based on the one or more sensor measurements;
• code to determine, when the acceleration meets a predefined threshold value, a direction of travel for the device based on a kinematics acceleration model which implements at least one motion-based constraint;
• code to calculate, when the acceleration does not meet the predefined threshold value, the direction of travel for the device based on a primary direction of acceleration for the device;
• and
• code to estimate a position of the device based on an output from a Kalman filter that receives an input corresponding to the direction of travel for the device.

A method comprising:

• performing, by a device, via one or more sensors of the device, one or more sensor measurements, the device being within or coupled to a vehicle in motion;
• determining an acceleration of the device based on the one or more sensor measurements;
• in response to determining that the acceleration meets the predefined threshold value:
• determining a direction of travel for the device based on a kinematics acceleration model which implements at least one motion-based constraint;
• estimating a position of the device based on an output from a Kalman filter that receives an input corresponding to the direction of travel for the device that was determined based on the kinematics acceleration model which implements the at least one motion-based constraint;
• determining another acceleration of the device based on one or more other sensor measurements performed via the one or more sensors of the device;
• determining that the other acceleration of the device does not meets the predefined threshold value;
• and
• in response to determining that the other acceleration does not meet the predefined threshold value:
• determining another direction of travel for the device based on a primary direction of acceleration for the device without using the at least one motion-based constraint;
• and
• estimating another position of the device based on another output from the Kalman filter that receives another input corresponding to the other direction of travel for the device that was determined based on the primary direction of acceleration for the device without using the at least one motion-based constraint.