Mercedes-benz Aktiengesellschaft

Temic Telefunken Microelectronic Gmbh

Jurgen Leuteritz

Matthias Gramann

Reinhard Helldorfer

Bernhard Topfer

Gerhard Hettich

A method is described for determining the wheel speed during braking of a vehicle having in addition to at least one wheel with speed sensor at least one further wheel without speed sensor and means for determining the braking pressure. For this purpose, the braking operation is subdivided into several time intervals during which the relative value from the braking energy and the kinetic energy of the vehicle are obtained, and the contribution of the wheels without speed sensors to the braking energy is defined during a first time interval. Furthermore, the ratio of the relative value in this time interval to the relative values in further time intervals is formed, and the mean value for the wheel speed of all wheels without speed sensors is ascertained in the further time intervals from the ratio of the relative values.

Method for determination of wheel speed

A method is described for determining brake coefficients, which define the relationship between the brake pressure and the brake force at a wheel or axle of a motor vehicle or of a section of a vehicle combination during the braking operation of the vehicle or vehicle combination. During the braking operation of vehicle, the wheel speed and the brake pressure are determined measurement/time intervals with differing brake pressure distribution between the wheels, axles or vehicle sections are formed, in which the equilibrium of forces between the brake force and the force of inertia of the motor vehicle is obtained. The mass-related brake coefficients of the brake-pressure-sensed wheels or axles and a mean value for the mass-related brake coefficient of all non-brake-pressure-sensed wheels or axles are determined from the equations for the equilibrium of forces in the measurement/time intervals; by forming the quotient between these mass-related brake coefficients, the relative brake force development of the individual axle (or of the individual section of the vehicle combination), i.e. its respective proportion of the total brake force sum, can be determined without the need to know vehicle-specific design data or the total mass.

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Nurnberg, Germany

Jurgen Leuteritz