In order to obtain the best energy recovery during regenerative braking, vehicles with an electrified drive train will increasingly be equipped with new brake systems which provide a free distribution of braking force between the wheel brake and the electric motor. The hydraulic brake system therefore has to be completely decoupled from the driver's input at the brake pedal. The generation of hydraulic pressure is designed for permanent operation in contrast to conventional ESCsystems. The feed-forward control based on the modification of the vehicle's self-steering gradient, introduces an approach to using brake interventions to improve driving dynamics which can be realized in way which is easy to apply. The next step is the implementation of the control algorithms in a real test vehicle. In the second part of this article, a function was presented which should improve the tractive potential and the driving comfort of vehicles with front wheel drive while accelerating rapidly from standstill. By predicting the occurring driving forces, excessive drag torque can be detected early enough. The overall longitudinal force at the wheel contact can be limited to the optimum amount by applying the appropriate brake torque at the right time. Moreover, the brake system can be pre-conditioned by the model-based prediction for controlling brake torque and for that reason the dynamic system behavior can be enhanced by software solely. The control algorithm can be adapted to a new operation point for driving situations which allow an adequate determination of the maximum friction potential. The frictional potential must then be updated dynamically.
Enhancing driving dynamics and traction by variable brake systems
2013
19 Seiten, 17 Bilder, 10 Quellen
Aufsatz (Konferenz)
Englisch
Enhancing driving dynamics and traction by variable brake systems
Kraftfahrwesen | 2013
|