From: testarne@athena.mit.edu (Thad E Starner)
Subject: Re:  Kalman filters
Date: Thu, 7 Nov 1991 02:37:57 GMT
Organization: Massachusetts Institute of Technology



> The reason is that the human motor system.does NOT use negative feedback
> directly, due to long neural delays (>100mS). 
>Instead, it relies on Kalman-type filters and task-specific motor programs
>learned through practice. 

The cool thing is you can use the filters to your advantage.  Just use
a Kalman filter to lead your renderer with.  That way you reclaim the lag time 
between getting the tracking data and displaying the required scene.  While
you've all heard me expound on predictive filtering before, here is an idea I'd
like someone to run with:

It may be possible to tweek the tracking Kalman filters to use the same modes 
as the human's filters.  That way no extra computation would be needed
(for instance, get rid of acceleration components if human's don't use it). 
The question is, of course, what modes are necessary, and how to deal properly with the inter-sensory components.  Setting up the proper experiments for this
seems non-trivial.

BTW, these issues have been dealt with by the Aero/Astro crew for a while now,
and there is actually some literature out there.  For a start I recommend

Oman, C. M. (1990).  Motion sickness: a synthesis and evaluation of the
sensory conflict theory.  Canadian Journal of Physicology and Pharmacology,
68, 264-303.