Honda 2007 Acura RL User Manual page 19

2005-08 ACCESSORIES AND EQUIPMENT Navigation System - RL
of the piezoelectric parts and "Coriolis force. "(Coriolis force deflects moving objects as a result of the
earth's rotation.) In the oscillation gyro, this force moves the sensor element when angular velocity is
applied.
Operation
1. The driving piezoelectric part oscillates the oscillator by repeatedly bending and returning when an
AC voltage of 6 kHz is applied to the part. The monitoring-side oscillator resonates because it is
connected to the driving-side oscillator by the metal block.
2. The monitoring piezoelectric part bends in proportion to the oscillation and outputs voltage (the
monitor signal). The navigation unit control circuit controls the drive signal to stabilize the monitor
signal.
3. When the vehicle is stopped, the detecting piezoelectric parts oscillate right and left with the
oscillators, but no signal is output because the parts are not bent (no angular force).
4. When the vehicle turns to the right, the sensor element moves in a circular motion with the right
oscillator bending forward and the left oscillator bending rearward. The amount of forward/rearward
bend varies according to the angular velocity of the vehicle.
5. The detecting piezoelectric parts output voltage (the yaw rate signal) according to the amount of bend.
The amount of vehicle direction change is determined by measuring this voltage.
Fig. 9: Enlarged View Of Sensor Element
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Global Positioning System (GPS)
The global positioning system (GPS) enables the navigation system to determine the current position of the
vehicle by using the signals transmitted from the satellites in orbit around the earth. The satellites transmit
the satellite identification signal, orbit information, transmission time signal, and other information. When
the GPS receiver receives a signal from four or more satellites simultaneously, it calculates the current
position of the vehicle based on the distance to each satellite and the satellite's position in its respective
orbit.
Position detection Image with GPS satellite
2007 Acura RL