| Electronic Stabilisation ProgramThe electronic stabilisation program detects critical driving situations, where there is a risk of the vehicle skidding for example, and implements effective measures to prevent the vehicle from breaking away. To enable the electronic stabilisation program to respond to such critical situations, the system must be fed constantly with data: for example, what direction the driver is steering in and what direction the vehicle is moving in. The answer to the first of these questions is provided by the steering angle sensor and the ABS speed sensors on the wheels. These two items of information allow the control unit to calculate the target steering direction and the target vehicle behaviour. Additional key data include the yaw rate and the lateral vehicle acceleration. The control unit uses this information to calculate the vehicle's actual status. The electronic stabilisation program prevents the vehicle from being destabilised when cornering as a result of either excessive speed, an unexpected change in the road surface (water, ice, dirt) or the driver having to perform a sudden evasive manoeuvre. The system takes corrective action regardless of whether the instability manifests itself as understeer - when the vehicle slides towards the outside of the bend despite the wheels being turned in the opposite direction - or oversteer, when the vehicle's tail swerves out. The electronic stabilisation program's computer unit uses the data supplied by the network of sensors to determine the nature of the vehicle's instability and governs the corrective response by intervening in the braking and engine management systems. If the vehicle is understeering, the electronic stabilisation program decelerates the rear wheel on the inside of the bend. At the same time, it reduces engine power until stability has been restored. The electronic stabilisation program counters oversteer by carefully applying the front brake on the outside of the bend and intervening in the engine and transmission management. This complex control system is subject to ongoing advancement as more and more experience with it is gained and sensors are developed which offer far greater sensitivity. Note: The electronic stabilisation program is unable to override the limits imposed by the laws of physics. If the driver pushes both the chassis and the electronic stabilisation program beyond their limit, not even ESP will be able to prevent an accident. |
