How can game developers make the Wii Remote more accurate for their game, using just software? Veteran developer Bertis Rasco discusses the use of Kalman Filtering equations
, more often used in airplane navigation systems, to improve the output of the Wii remote's accelerometer.
In this excerpt, Rasco explains how, generally speaking, these Kalman Filter equations could be put to use with regards to improving the Wii's motion sensitive controller:
“The description, justification, and general use of the Kalman Filter is challenging, so I will merely state the results that are relevant and then go through an example. There are a few good, and more so-so books and web pages on Kalman Filtering. I list in the references only what I consider good pages, so please realize that it is a subjective list. Good luck with them. Familiarity with differential equations, some statistics, and matrix mechanics is assumed throughout this article.
After the basic Kalman Filter equations, this article discusses a 'simple' Kalman Filter example. The 'simple' example is a one dimensional motion of an accelerometer and with ideally fairly accurate position measurements. I use the word simple only because this is as uncomplicated as Kalman Filtering gets. It does not describe the example as something that is necessarily easily understood.
This example has nothing in it that explains how to extract the orientation of the Wiimote, that is the next level up in complexity of a Kalman Filter design. This example is perfect for estimating the motion of an object in one dimension, like the motion of a pool cue before it strikes the cue ball.”
You can now read the entire feature
, which includes a detailed look at the potential use of Kalman Filtering in extracting accelerometer data from the Wii remote, including example equations and code samples (no registration required, please feel free to link to this feature from external websites).