World's first sensor cluster with yaw rate and acceleration sensors in one SMD-component
Jul 23, 2009
Continental integrates the sensors required for ESC and other safety and assistance systems using silicon technology. Benefits include compact design, higher performance and lower costs.
Frankfurt am Main, Germany. Continental, the global automotive supplier, is the first manufacturer in the world to integrate the yaw rate and acceleration sensors required in particular for Electronic Stability Control (ESC) into a single central component. “With this development, Continental is remaining true to its philosophy of making safety systems such as ESC available to all motorists,” said Dr. Ralf Schnupp, Head of Inertial Sensors at the Chassis & Safety Division. “Compact design, a higher level of resistance to vibration and temperature, and lower costs are helping us to achieve this goal. At the same time, the complete integration in silicon technology is offering us the option of making highly-developed assistance systems such as Adaptive Cruise Control or Active Front Steering even more effective through the use of high-precision sensors, and further developing our ContiGuard® safety system.” The new cluster will go into series production with several vehicle manufacturers at the beginning of 2010.
Yaw rate and acceleration sensors in one SMD-component Click here to download this image.
Yaw rate sensors in silicon technology
Acceleration and yaw rate sensors are key to providing ESC with the necessary information about the vehicle's condition. The system measures the turning speed of the wheels, the car's lateral and longitudinal acceleration, steering movements, yaw ratio and rotational speed. It uses all of this data to accurately calculate in which direction the vehicle is traveling and the driver is steering. To date, micromechanical sensors have been used specifically for the acceleration sensor. Now, for the first time ever, purely capacitive sensors made exclusively from silicon will be used for yaw rate and acceleration sensing. These are more cost-effective and offer higher resolution, i.e. increased sensitivity to measurement. They also ensure only very slight deviations in measurement accuracy in series production – and, above all, only slight deviations in measurement readings over a long service life.
One of the biggest challenges facing development engineers when attempting to integrate the sensors into one component was preventing unwanted frequencies and signal cross-talk between sensors. Through the use of silicon sensors, Continental has successfully achieved a higher level of resistance to this type of resonance and vibration, as well as to ambient temperatures of up to 125°C.
The compact design of the sensor cluster means it takes up less space in the vehicle, making it easier to fit and more cost-effective, and also enabling the use of ESC in models of all vehicle categories. Through the integration of the combined yaw rate and acceleration sensor in ESC or airbag control units, reliability in safety-critical applications is increased still further as fewer external components have to be used and linked together.
High precision for additional applications and self-diagnosis
In addition to the standard application for ESC, use of the new sensor cluster also meets with so-called high-precision specifications. This further improves the performance of highly-developed systems such as Adaptive Cruise Control (ACC), Active Front Steering and Intelligent Headlamp Control. It also increases the accuracy of fault monitoring on redundant systems. On intelligent cruise control, for example, these more powerful sensors offer improved radar accuracy.
The highly integrated signal processing monitors and analyzes all internal signals. This covers all levels of the signal chain. If the system detects a fault, it is saved in a separate, non-volatile memory and can be read using diagnostic equipment. This expands the range of diagnostic options, both for the sensors themselves and for the sensor cluster as a whole.In turn, this further enhances the overall product quality and represents a major step towards achieving the Continental quality objective: zero defects.