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Message: <blockquote data-quote="KL2DC" data-source="post: 203287" data-attributes="member: 3452">Active Steering does work together with the car's stability controls (DTC, DSC, DBC, FTM, ABS, ABD, Hill Assist are all part of the same package). DSC would actually intervene in instances where the yaw rate of the car crosses a certain threshold and dial in some degrees of counter steer via the AS. This is in addition to the braking and throttle modulation tools the DSC employs to keep your ass on the road. To me this is the best value of AS, I am not a big fan of variable ratio steering wheels in general but automatic and instantaneous counter steer when needed is pretty darn cool! <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite7" alt=":p" title="Stick Out Tongue    :p" loading="lazy" data-shortname=":p" />  Brief tech recap...(and because Herr Schwepps would expect nothing less <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite7" alt=":p" title="Stick Out Tongue    :p" loading="lazy" data-shortname=":p" /> ) BMW’s active steering system is an all-mechanical steering linkage that accepts, and at all times utilizes, two separate steering inputs—one from the driver and one from the car’s steering algorithm. At its most basic level, BMW’s system can modify the gain between the steering wheel input and the front wheels’ rotation angle, where the steering ratio is determined as a function of vehicle speed. During low-speed operation, the gain is moved to a high value, leading small rotation angles of the steering wheel to induce large rotation angles of the wheels (10:1 steering ratio of driver input to wheel output, which corresponds to a high gain and thus low ratio). This ratio allows the driver to maneuver the car with small steering inputs, removing the need for armover-arm turning of the steering wheel. High sensitivity to driver inputs, however, is undesirable during high-speed driving since minor, inadvertent steering wheel disturbances can induce large lateral movements of the vehicle. To avoid this problem, the steering ratio is increased (and thus gain and sensitivity are decreased) as speed increases, up to a maximum ratio of 20:1. Standard steering systems, or cars without active steering systems, have a fixed ratio of 14.1:1, which represents a compromise between the needs of low- and highspeed operation.The guiding rationale for allowing the DSC system to take control from the driver is that there may be instances when the driver loses, or is on the verge of losing, control. For example, a slippery road condition may be encountered during a turn, or a driver may enter a turn at a speed that is too high for the tires to maintain sufficient lateral force, which can occur if an unexpected obstacle is encountered on the road. In each case the driver, due to insufficient training and experience, may apply too much steering input or actually steer in the wrong direction (wrong in the sense of what is needed to stabilize the vehicle). With sufficient sophistication to determine the correct steering input, the stability algorithm can act to override the driver’s destabilizing input. The equations of motion governing the car’s response characteristics define an internal reference model of the vehicle. The output of this reference model, based on the vehicle’s known input conditions, is then used to determine whether the vehicle is responding acceptably to the driver’s commands. For instance, suppose that the driver is rounding a corner. The stability control algorithm checks to see whether, based on the tire’s slip angle, steering angle, and longitudinal speed, the yaw rate matches the rate required to negotiate the turn in a nominal manner. A yaw rate that is too high implies an oversteering condition, while an even more extreme yaw rate indicates that the car is in a spin. If the yaw rate is beyond the acceptable limits predefined by the algorithm, the brakes are activated at individual wheels and the throttle is modulated. The aim of these actions is to bring the car back on track, if possible.In David's case, since the alignment/steering is off center, I imagine the yaw rates readings were out of spec setting off the christmas tree warning lights chain reactions.</blockquote>

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