Tracking in a moving platform

An apparatus comprising:

• a processor;
• and
• computer storage memory having computer-executable instructions stored thereon which, when executed by the processor, implement a method comprising:
• receiving, from an inertial measurement unit on an entity in a moving platform, data sensed by the inertial measurement unit;
• receiving, from a sensor on a second inertial measurement unit on the moving platform, visual tracking data computed from images depicting the moving platform or the entity in the moving platform;
• and
• computing a three-dimensional (3D) position and orientation of the entity by estimating a plurality of states using the received visual tracking data and the received data sensed by the inertial measurement unit, wherein the plurality of states comprises a state of the moving platform and a state of the entity.

A system comprising:

• a mobile computing device having an inertial measurement unit, the mobile computing device being mounted on a moving platform in use;
• an apparatus for tracking three-dimensional (3D) position and orientation of an entity in the moving platform, the apparatus comprising:
• a processor;
• and
• computer storage memory having computer-executable instructions stored thereon which, when executed by the processor, implement a method comprising:
• receiving, from the inertial measurement unit, data sensed by the inertial measurement unit;
• receiving, from a sensor on a second inertial measurement unit on the moving platform, visual tracking data computed from images depicting the moving platform or the entity in the moving platform;
• determining a position and orientation of the mobile computing device;
• and
• computing the 3D position and orientation of the entity by estimating a plurality of states using the received visual tracking data sensed by the inertial measurement unit and the determined position and orientation of the mobile computing device, wherein the plurality of states comprises a state of the moving platform and a state of the entity.