Updating vehicle attitude for extended dead reckoning accuracy

A device for vehicular navigation, the device comprising:

• an inertial navigation system (INS);
• a memory;
• and
• one or more processors communicatively coupled with the INS and the memory, wherein the one or more processors are configured to:
• determine a first attitude of a vehicle with respect to a reference frame at a first epoch, the determined first attitude including a determined first roll angle;
• based on measurement data from the INS, determine an attitude of the INS at a second epoch that is subsequent to the first epoch;
• based on the determined attitude of the INS at the second epoch, determine a second attitude of the vehicle at the second epoch;
• update the determined second attitude of the vehicle based on a determination that an absolute change in a yaw angle of the vehicle between the first epoch and the second epoch is less than a predetermined threshold, by setting a roll angle of the determined second attitude of the vehicle to equal the determined first roll angle;
• determine, based on the updated second attitude of the vehicle, an updated attitude of the INS;
• and
• navigate the vehicle based on the updated attitude of the INS.

An apparatus for vehicular navigation, the apparatus comprising:

• means for determining a first attitude of a vehicle with respect to a reference frame at a first epoch, the determined first attitude including a determined first roll angle;
• means for determining an attitude of an inertial navigation system (INS) of the vehicle at a second epoch that is subsequent to the first epoch, based on measurement data from the INS;
• means for determining a second attitude of the vehicle at the second epoch based on the determined attitude of the INS at the second epoch;
• means for updating the determined second attitude of the vehicle, based on a determination that an absolute change in a yaw angle of the vehicle between the first epoch and the second epoch is less than a predetermined threshold, by setting a roll angle of the determined second attitude of the vehicle to equal the determined first roll angle;
• means for determining an updated attitude of the INS based on the updated second attitude of the vehicle;
• and
• means for navigating the vehicle based on the updated attitude of the INS.

A non-transitory computer-readable medium storing instructions for vehicular navigation, the instructions comprising code for:

• determining a first attitude of a vehicle with respect to a reference frame at a first epoch, the determined first attitude including a determined first roll angle;
• determining an attitude of an inertial navigation system (INS) of the vehicle at a second epoch that is subsequent to the first epoch based on measurement data from the INS;
• determining a second attitude of the vehicle at the second epoch based on the determined attitude of the INS at the second epoch;
• updating the determined second attitude of the vehicle based on a determination that an absolute change in a yaw angle of the vehicle between the first epoch and the second epoch is less than a predetermined threshold by setting a roll angle of the determined second attitude of the vehicle to equal the determined first roll angle;
• and
• determining an updated attitude of the INS based on the updated second attitude of the vehicle;
• and
• navigating the vehicle based on the updated attitude of the INS.