The idea is to have something like an ODROID U2 (a small Android device with the same SoC as the Samsung Galaxy S3) attached to a belt along with a USB battery pack & to have sensors monitor your current position within the building & your current head orientation & control the virtual view appropriately.
My first question is about head tracking, which I know there is a lot of knowledge about here. In particular, I'll need to keep track of the *absolute* heading/bearing of the head (eg which direction you are facing as you walk around the building). Is this possible using a regular head tracker that combines accelerometer, gyroscope & magnetometer? In all of the head tracked HMD videos I've seen thus far it seems as though it would work, however the user is generally stationary in these videos; not walking around a building. How quickly will drift become an issue, particularly with changing magnetic surroundings? I've done something similar outdoors with a tablet & Second Life, using a magnetometer to get heading & an accelerometer to get pitch, however a magnetometer is useless for getting headings inside buildings full of metal girders, HVAC ducting & cables.
My second question is about indoor positioning. I've done lots of reading, including a whole thesis on categorizing/comparing different systems, but haven't found something suitable. I think I'll need accuracy of at least <50cm for the system to work at all. Ultrasonic systems seemed promising. Things like the Cricket system from MIT achieved accuracy of 1-2cm, however that project seems to have been dead since 2006 & I can't find any modern replacement/alternative. There are numerous commercial systems available today, such as those from Sonitor, however these are only concerned with 'sub room' accuracy & are pricey; Sonitor do a research kit that is $2990 & only contains enough hardware to divide a single room into 3 or 4 zones (presumably with no finer position than which zone you are in, where a zone might represent quarter of a room). Does anybody know of a good option? I know there are projects on here that use Kinect & Playstation Move, however I don't know how well that would scale to a whole building.
Any other ideas, links to similar/existing projects, etc. would be highly appreciated
