Navigation Systems: Operation
Vehicle speed sensor sends a 4-pulse signal, per revolution, to the navigation unit. VSS outputs the distance signal by turning navigation unit's sensor power on and off, which calculates distance traveled. Yaw rate sensor is an oscillation gyro built into navigation unit. Yaw rate sensor detects direction change (angular speed) of vehicle. GPS antenna receives electric waves from GPS satellites and transmits to GPS receiver, which is built into the navigation unit. Vehicle position and signal reception condition is transmitted from GPS receiver to navigation control for tuning of vehicle position. Navigation unit calculates vehicle position and provides a guide to a destination. Navigation unit performs map matching correction, GPS correction, distance tuning menu functions and the hard disk drive. Navigation unit then transmits a signal to the display unit and audio driving instructions to the audio unit.
There are four options the navigation unit can compute for different routes to a selected destination:
- Direct Route - A route that is most direct, that will take the least amount of time.
- Easy Route - A route that minimizes the number of turns needed.
- Minimize Freeways - A route that avoids freeway travel or keeps freeway travel to a minimum.
- Minimize Toll Roads - A route that avoids or minimizes travel on toll roads.