5 Conclusion and Perspectives
In this paper we have introduced Inertial Navigation System or INS for indoor and outdoor position tracking. This navigation system has advantage over the GPS be-cause it is independent on satellite signals and it can be used both indoor and outdoor. The system can be used in places where GPS signals are unavailable such as in build-ings and underground. INS uses inertial measurement units (IMUs) such as accel-erometers and gyroscopes for measurements. The orientation can be tracked by gyro-scopes, whereas acceleration can be tracked by accelerometers. By integration of the gyroscope signals, we will get the orientation. Global coordinates of acceleration can be calculated using the known orientation calculated from the gyroscopes. The global acceleration signals then have to be subtracted from the acceleration due to the earth gravitation and double integration to get the position. However, is impossible to track position using inertial sensing alone for more than one second due to errors from the IMUs.We first have to correct the errors to get the accurately position. To do so, in the case of NavShoe, it uses ZUPTs method to reset the velocity to zero for each stance phase as pseudo measurements and applies these measurements into the EKF to correct the navigation errors. The IMUs can be attached on a shoe which called IC3. IC3 is a wireless component and it has a receiver which can be attached to PDAs or wearable computing to visualize and calculate the navigation. The experiment re-ported acceptable results. That is, the total drift was 0.06 percent of the distance trav-eled. The time travel was 322 seconds with three rounds. However, the report has not described if the test person has only walked or also mixed between walking and run-ning actions. We believe that the research in this area is growing as can be seen in [2] and hopefully, the IMU prices will soon be decreased.