Dr. Ing. H.c. F. Porsche Aktiengesellschaft

Other

Lothar Witte

Norbert Stelter

Rainer Wuest

Matthias Dietz

Harald Nonn

Ulrich Appt

Stephan Lawitzki

Stefan Germann

Georg Abler

Wolfgang Kopecky

Hai Tran Xuan

Peter Brodbeck

Klaus-Gerhard Wolpert

Rolf Geiger

Michael Pfeiffer

Method of simulating the performance of a vehicle on a roadway on a power train test bed with the help of torque-controlled electric load machines mounted on the shafts of the power train of the vehicle and with the help of a computer with a vehicle model stored therein and a tire model simulating the slip-dependent friction, in which method the angular wheel speed is measured on at least one of the shafts, and the tire model determines a force transmitted from the tire to the roadway at this angular wheel speed on the basis of the tire model using a vehicle velocity and a tire normal force, and it also determines a setpoint torque for this force for the torque-controlled load machine mounted on this shaft, in such a way that a difference corresponding to the actual slip is established between the measured angular wheel speed and a nominal angular wheel speed value corresponding to the vehicle velocity used in the tire model and calculated in the vehicle model with feedback of the force transferred to the road surface.

Method of simulating the performance of a vehicle on a road surface

The arrangement controls a friction element for limiting a rotational speed compensation between the axles of a two-axle or all-wheel-driven vehicle as a function of the difference of the medium wheel speeds of both axles (longitudinal speed difference). This longitudinal speed difference is compared with two driving-speed-dependent tolerance bands, the first tolerance band being determining for positive and the second tolerance band being determining for negative longitudinal speed differences. If the values of the longitudinal speed differences are above the first or below the second tolerance band, the limiting is increased; if the values are within the tolerance bands, the instantaneous limiting is maintained; and if the values are between the tolerance bands, the limiting is reduced. This arrangement may also be expanded to include an adaptation device of the limit criteria with respect to different tread radii of the wheels and a cornering correction device.

Arrangement for controlling the power transmission to at least two axles

A control arrangement for a four-wheel drive vehicle which has at least one gear box or differential with controllable power transmission characteristics having circuitry for producing control signals in response to vehicle operating conditions and parameters. The arrangement allows for control of the distribution of torque to the respective wheels of the vehicle as a function of a selected number of parameters, such as relative or average wheel speed, engine speed, gas pedal or throttle valve angle, etc. The arrangement contemplates the simultaneous control of more than one adjustable gear box or differential as a function of commonly and/or separately sensed parameters.

Control arrangement for four-wheel drive vehicles

Growing community of inventors

Vaihingen, Germany

Lothar Witte