Mercedes-benz Aktiengesellschaft

Daimler Chrysler Ag

Matthias Baumann

Gerhard Fischle

Ralph Klingel

Carola Pfister

Thomas Mieslinger

The invention relates to a method for testing the functioning of a driving dynamics control sensor system of a vehicle, said sensor comprising a yaw rate sensor, a transverse acceleration sensor and/or a steering angle sensor. According to the invention, the measuring signal values supplied by the driving dynamics control sensor system in the momentary test starting state of the vehicle are established as the starting values at the beginning of a testing operation. The measuring signal values that are supplied continuously throughout a subsequent test drive, which includes driving around a bend at a predetermined longitudinal speed, are compared with said starting values during said test drive. An error by the sensor system is detected depending on the results of the comparison of the measuring signal values supplied during the test drive with the corresponding starting values. The invention also relates to the use of the inventive method for e.g. testing the functioning of the driving dynamics control sensor of an automobile before it is driven for the first time or following repairs.

Method for testing the functioning of a drving dynamics control sensor system

A method balances wheel speeds for a motor vehicle having a wheel-slip control system. Quick coarse balancing with respect to a reference wheel are provided in stages and subsequent fine balancing in pairs of wheels, either on the same side or on the same axle. Cornering is not detected from the left/right deviation of an axle, but from the temporal variation in the differentiated left/right deviation to achieve a very sensitive and reliable wheel balancing.

Motor vehicle wheel speed balancing method

A method for electronic traction systems using brake intervention on the low-adhesion wheel damps and thereby substantially avoids the undesired traction control oscillations, such as pull-away tramping and drive train oscillations. In particular, an interchange of the low-adhesion wheel to be controlled from one driving wheel to the other is undertaken only when the rotational speed of the previous high-adhesion wheel is greater by a certain amount than that of the previous low-adhesion wheel and when there is no longer any controlling brake pressure at the latter. Also or in addition, the threshold value for the activation of the brake intervention is set to increase traction dynamically by suitably raising the threshold value when drive train oscillation behavior is recognized.

Motor vehicle traction system control oscillation damping method using

A method for increasing the drive torque achieves the action of a differential lock in that controlled brake engagement takes place on one side of a driven axle provided that there is a speed difference between the wheels on the different sides of a driven vehicle axle which exceeds a threshold value. The regulation engagement is started even when there are only small speed differences between the wheels on the two sides of the driven axle. A reference velocity of the vehicle is determined and, on the basis of the determined reference velocity, wheel calibration and cornering correction take place, and thereafter, the speed difference is determined therefrom. The speed difference thus determined is substantially based on the difference in the adhesion on both sides of this axle.

Method for increasing drive torque with controlled brake engagement

Method for tire pressure warning in a motor vehicle in which, instead of direct pressure measurement, the tire pressure is monitored indirectly by recording the dynamic rolling circumference of the tire and, in this way, to dispense with sensors, in particular if wheel speed sensors have already been installed in the vehicle. The method works on the basis of a wheel speed balance, within which speed scaling factors are determined. By comparing these scaling factors in pairs, determining the maximum deviation and checking whether a particular threshold value has been exceeded, a reliable tire pressure warning can be implemented with little outlay, in particular in the case of a wheel speed balance for each axle.

Method for tire pressure warning

A method controls the driving stability in the event of increased slip at the driving wheels of a motor vehicle having an electronic traction system with braking intervention at the driving wheels. With excessive high-adhesion wheel slip, synchronous braking intervention on both sides is undertaken at the driving wheels when the vehicle is travelling around a curve. A reduction takes place in the brake pressure at the low-adhesion wheel, as used for controlling drive slip or increasing traction, when the vehicle is travelling in a straight line, the high-adhesion wheel slip is used as the control parameter in either situation. This method permits braking interventions at the driving wheels for the purpose of controlling drive slip and/or for increasing traction while still maintaining a high level of driving stability.

Traction control method for stabilizing motor vehicle motion in the

The invention provides a process for performing calibration of the wheel speeds of a motor vehicle by periodically calculating and applying correction factors. The instantaneous speed of each wheel is measured periodically, and a vehicle turning rate is determined based on the time derivative of the differential between left and right wheel speeds. Actuation of the vehicle brakes is also detected. According to the invention, a new correction factor is determined only after the following criteria have been satisfied concurrently for a predetermined time period: vehicle speed is above a specified minimum, acceleration is within a specified range, vehicle turning is below a specified limit and the brakes are not actuated. In a second embodiment, vehicle driving torque is used as a criteria in place of acceleration.

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Boeblingen, Germany

Matthias Baumann