Mercedes-benz Aktiengesellschaft

Daimler-benz Ag

Erich Schindler

Walter Klinkner

Frank-Werner Mohn

Thomas Wohland

Adam Zomotor

Bernd Danner

A method and apparatus for preventing vehicle handling instabilities, in which a vehicle yaw angular velocity required value (.mu..sub.soll) is formed from measured quantities (vehicle velocity, steering wheel angle). The vehicle yaw angular velocity actual value (.mu..sub.ist) is formed from at least one sensor signal, the difference between the yaw angular velocity required value (.mu..sub.soll) and the yaw angular velocity actual value (.mu..sub.ist) is determined by subtracting the yaw angular velocity actual value (.mu..sub.ist) from the yaw angular velocity required value (.mu..sub.soll), and the handling situation or the vehicle yaw behavior to be detected is determined from this difference. The time derivative of the difference is formed to determine whether the vehicle exhibits understeer or oversteer. The slip threshold value (.sigma..sub.soll) is varied in the direction of the value 0 when it is deduced from the detected handling situation that a changed lateral guidance force is required on the wheels of the vehicle driven axle.

Method and apparatus for preventing vehicle handling instabilities

A method detects the driving situation with respect to the yaw behavior of the vehicle, in which a desired value of the vehicle yaw angle rate .mu..sub.des is derived in a computer unit from measured values (such as vehicle speed, steering wheel angle), and at least one sensor signal is supplied to the computer unit from which the actual value of the vehicle yaw angle rate .mu..sub.act is derived. The difference between the desired value of the yaw angle rate .mu..sub.des and the actual value of the yaw angle rate .mu..sub.act is formed in the computer unit. The actual value of the yaw angle rate .mu..sub.act is subtracted from the desired value of the yaw angle rate .mu..sub.des, and at least one output signal is generated in and emitted by the computer unit from this difference. The output signal represents the detected driving situation with respect to the yaw behavior of the vehicle. The magnitude of the time derivative of the difference is used to derive whether there is a tendency towards an increasingly critical driving situation.

Method for detecting driving situation with respect to vehicle yaw

A method and apparatus prevents instabilities in vehicle handling by forming a desired value of the vehicle yaw angle rate .mu..sub.des from measured values (namely, vehicle speed, steering wheel angle), and forming the actual value of the vehicle yaw angle rate .mu..sub.act from at least one sensor signal. The difference between the desired value of the yaw angle rate .mu..sub.des and the actual value of the yaw angle rate .mu..sub.act is formed by subtracting the actual value of the yaw angle rate .mu..sub.act from the desired value of the yaw angle rate .mu..sub.des. At least one output signal is generated and emitted by the computer unit, from this difference. The output signal represents the detected driving situation with respect to the yaw behavior of the vehicle, with the brake pressure of individual wheels of the vehicle being varied as a function of this output signal, and the output signal being generated in the computer unit as a function of a time derivative of the difference. The output signal contains information on whether the vehicle has understeering or oversteering handling. In the case of oversteering handling, the brake pressure is increased for the vehicle front wheel on the outside of the turn; in the case of understeering handling, the brake pressure is increased for the vehicle rear wheel on the inside of the turn.

Apparatus and method for preventing instabilities in vehicle handling

A method for controlling drive slip permits the maximum drive torque which can be transmitted by the driven wheels to be determined and transmitted to a central control device of the internal combustion engine. On the basis of this transmitted value, the central control device determines how the setting parameters of the internal combustion engine have to be adjusted in order to avoid excessive drive slip. An interaction occurs between the drive slip control and further open-chain and feedback control devices which supply signals to the central control device of the internal combustion engine.

Drive slip controlling method

The supplementary steering system operates automatically as a function of the change of the transverse velocity (v.sub.y) of the vehicle to provide compensation steering movements to stabilize a vehicle in skidding situations. The system relies on the fact that a great increase invehicle transverse velocity is characteristic of skidding movements. Critical travel conditions can be stabilized by a rapid reaction to the change of transverse velocity. Under steady travel conditions, i.e., when only a negligible change of transverse vehicle velocity occurs, the supplementary steering system is not actuated, or is reset to its central position.

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Unterweissach, Germany

Erich Schindler