The low cost sensors are not nearly accurate enough for long range
navigation, maybe by 2 or 3 orders of magnitude in terms of noise, scale
factor and offset drift characteristics. The better sensors of the mems
or quartz type cost around 50 x as much as the consumer grade types and are
used in standalone heading reference systems from vendors like meggit
and goodrich, to name a couple.
There quite a few vendors of low cost sensor systems designed for
robotics and short range orientation and navigation applications. They
tend to use mems accelerometers and rate gyros from analog devices etc.
These have reasonable performance, but there are even lower cost mems
rate gyros and accelerometers available for use in consumer electronics
(games, mobile phones, hand held computers) and vehicle body rate
control. None of these are anywhere near as good as fibre optic
or laser ring gyros, which are used in high accuaracy ins systems.
A few examples using low cost technology:
ADXRS642 | Vibration Rejecting ±250°/s Yaw Rate Gyro | Gyroscopes | MEMS and Sensors | Analog Devices
autopilot: Do it yourself UAV
Avionics, Flight Control and Engine Control Systems by PC Flight Systems
No connection, usual disclaimers etc.
There are loads of academic papers describing projects built around low
cost sensors on the web...