A new model based control approach for electric power steering systems will be presented in this paper. This control scheme focuses on the improvement of road feedback, which is an essential part of good steering feel. Knowledge about the systems mechanics and basic control theory is used. Their combination impose a way to achieve natural road feedback, but also offer the possibility to manipulate the gained information for the driver. Additionally it will be seen that this approach is also supporting the vehicles axle self aligning characteristics. The basic problem for reduced road feedback is explained in the next section. Afterwards a simplified and suitable control oriented model is given for the considered EPS (Electric Power Steering) system. In addition the basic aspects of the developed algorithm are described briefly and in a very general way in order to make it understandable for all readers. A linear quadratic regulator (LQR) is chosen as an controller example and further literature references are given. Finally the suitability and effectiveness of the considered approach is shown by selected simulation results. The latter remarks show that a significant change in force feedback for EPS-systems can be achieved by following the presented control approach. The figures illustrate that the IFC-EPS has very similar characteristics compared to the HPS (Hydraulic Power Steering). The feedback information can be manipulated in a suitable way with standard approaches. This are e.g. frequency oriented filters and the superposition of previously detected inverted oscillations. The side effects on the self-stabilizing axle aligning behaviour are impressive. In addition complete knowledge about the forces acting at the steering rack opens up new possibilities for constitutive developments. In the future a more detailed study on steering moment modules and suppression of non useful feedback information is desired. Finally the control algorithm has to be evaluated on a test bench or in a car.
Control-based potentials for electric power steering systems to improve road feedback and self aligning characteristics
Regelungsbasierte Potenziale für elektrische Lenkhilfesysteme (EPS) zur Verbesserung der Straßenrückkopplung und der Selbsteinstellkenndaten
2010
19 Seiten, 10 Bilder, 20 Quellen
Conference paper
English
Automotive engineering | 2010
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|British Library Conference Proceedings | 2006
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