GF42.45-P-5120GZ Yaw Rate and Lateral Acceleration Sensor, Component Description

GF42.45-P-5120GZ Yaw rate and lateral acceleration sensor, component description

Component Identification:

The micro mechanical yaw rate sensor (micro mechanical yaw rate sensor AY pickup) is located in the vehicle interior. It records the rotational speed of the vehicle about the vertical axis and the force of the lateral acceleration during cornering or skidding motions.

The pickup consists of one sensor to detect the rotational speed about the vertical axis and one sensor to detect the lateral acceleration. These sensors are combined into one housing. This reduces installation space considerably.

Function
The micro mechanical sensor system converts the lateral acceleration and rotational speed about the vehicle's vertical axis into electrically usable signals. The respective vehicle movements result in different displacements of the various types of masses.

Signal changes are recorded electronically and passed on to the ESP control unit via a CAN bus (Dynamics CAN) specially designed for the sensor to the ESP control unit (N47-5).





Function of lateral acceleration
The measuring principle of the lateral acceleration sensor is based on a deflection/extension and mass system with capacitive detector. The voltage is supplied via the ESP control unit. The lateral acceleration which occurs during cornering causes the mass element to move against the flexible bar (that functions like a spring) from its normal position to a position corresponding to the magnitude of the lateral acceleration.

Every change in position changes the electrical capacitance of the detector. An electronic analysis system produces a voltage signal afterwards which depends on the capacitance and therefore on the lateral acceleration of the vehicle. This voltage signal is evaluated by the ESP control unit.





Function of rotational speed
A micro mechanical silicon ring structure which is made vibratory via 8 bridges is used as a sensor element. The oscillations are induced electro magnetically. Under the influence of a yaw rate, additional forces (Orioles) act on the vibration structure. These Coriolis forces change according to the rotational speed.

These Orioles forces are also read out electro magnetically. After conditioning in a sensor-specific way, they are supplied as an analog signal to the signal processor inside the instrument cluster. The sensor electronics provide an output signal for the ESP control unit.