Today I did some ten 10 minutes walks around our lab (the film runts at x20). Some better, some worse, nothing censored. Two MIMU22BT modules on the top of the forefeet and a Samsung Galaxy S3 Android phone were used. Step-wise inertial navigation and wireless transmission of the steps to the phone where the dead reckoning was performed. No magnetometers, only accelerometers and gyros. Fusion of the two dead reckoning systems on the phone.
The shown trajectories are rather benign. Plain walking in a bounded area will certainly not stress the system but I hope it gives you a feeling for the performance of the modules during a reasonably realistic scenariou and not a worst case scenariou (straight line) which I would typically use to assess the performance.
I did 5 walks, charged the modules, and then did 5 more walks. I let the modules warm up for 20 minutes before the walks. Yes, the modules can give worse performance during warm-up.
The map is manually adjusted to the first lap of the trajectory. No perfect fits. Difficult with clumsy fingers on a small screen. I did not want to adjust it after the first lap since it would be cheating. The bars around the edges of the screen indicate 5 meters. The building is roughly 15x50 meters. Consequently each walk is around 700m.
The modules were calibrated a few hours before the walks.
Why 10 minutes? Well, we have a limitation in our Android software which means we can plot at most 10 minutes of history. Also, over 10 minutes, the errors are reasonably small such that the results don't look too messy. Note that the earth rotates some 2.5° over 10 minutes.
What you see is a playback of what I saw during the walks. That's why you see a charging symbol every now and then. Simultaneous screen capture would require four arms or reliable WiFi over the floor. I had neither.
For more information see:
[1] John-Olof NilsÂson, Amit K Gupta, and Peter HänÂdel. Foot-mounted inerÂtial navÂiÂgaÂtion made easy ‚ In proc. IPIN 2014, Oct. 28–30, 2014.
[2] John-Olof NilsÂson, Dave Zachariah, Isaac Skog, and Peter HänÂdel, CoopÂerÂaÂtive localÂizaÂtion by dual foot-mounted inerÂtial senÂsors and inter-agent rangÂing EURASIP JourÂnal on Advances in SigÂnal ProÂcessÂing 2013, 2013:164
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