Inertial navigation system (INS)

Inertial navigation system (INS)

Aircraft, submarines, INERTIAL NAVIGATION and missiles use inertial navigation systems (INS). INS
SYSTEMS (INS) measure movements electronically through miniature accelerometers. As
long as the movements are smooth, with no sudden jarring, and the samples
are taken frequently, an INS can provide accurate dead reckoning to 0.1
percent of the distance traveled.52 However, this technology is unsuitable for
mobile robots for several reasons. The cost of an INS is prohibitive; units run
from$50,000 to $200,000USD. The cost is due in part to having to stabilize the
accelerometers with gyroscopes, as well as the nature of precision electronics.
Mobile robots often violate the constraint that motion must be smooth.
A hard bump or sudden turn can exceed the accelerometers’ measurement
range, introducing errors. INS sytems are typically big; smaller devices have
less accuracy. Sojourner, the Mars rover, carried an INS system. In one trek,
it would have stopped 30 cm from a rock it was to sample if it had just used
proprioception. Instead, by using exteroception, it got within 4 cm.