Thank you all. I will investigate the Wii sensor and also the GPS solution. As noted by Dave, I am looking for an inexpensive and unobtrusive solution. In the USA we us a variety of methods to align patients including optical tracking, IR tracking, stereotactic localization, and electromagnetic...
Yes thanks Dave. That is exactly the type of application I am considering. I just don't know how accurate these types of sensors can be. For patient setup we need to be on the order say 3 mm or less. Once setup the patient will remain fixed and we no longer need the inertial navigation.
The device is something that will attach to a patient, likely through some type of bite block. The goal is to orient and position the patient's head to a specific location within the room. So no wheels ;)
Thank you Berkeman for the response but I am just using the pencil as an example. I'm trying to get a feel for using inertial navigation over a small range. Other options such as encoders, IR, optical tracking have limitations for my application.
As an example, let's say I'm tracking the movement of a pencil as a I draw a simple sketch in less than 5 minutes. The pencil is initially zeroed at a location located 2 feet away. Are there sensors accurate enough to track the pencil on the order of millimeters?
Very good observation about IR. Infrared is used for the application I have in mind but I believe it will be more costly and involved than something based on accelerometers/gyros. My goal is to implement this in a developing country that has limited resources.
I'm interested in applying inertial navigation over a very small range < 2 meters. Everything I have seen so far that is related to using inertial navigation for dead reckoning is for very large scales and gives accuracy on the order of fractions of miles or several feet. Does anyone know what...