DocumentCode :
1249596
Title :
A New Control Strategy of an Electric-Power-Assisted Steering System
Author :
Marouf, Alaa ; Djemai, Mohamed ; Sentouh, Chouki ; Pudlo, Philippe
Author_Institution :
Lab. of Autom. Control, Mech. Eng., & Comput. Sci., Univ. of Lille Nord de France, Valenciennes, France
Volume :
61
Issue :
8
fYear :
2012
Firstpage :
3574
Lastpage :
3589
Abstract :
The control of electric-power-assisted steering (EPAS) systems is a challenging problem due to multiple objectives and the need for several pieces of information to implement the control. The control objectives are to generate assist torque with fast responses to driver´s torque commands, ensure system stability, attenuate vibrations, transmit the road information to the driver, and improve the steering wheel returnability and free-control performance. The control must also be robust to modeling errors and parameter uncertainties. To achieve these objectives, a new control strategy is introduced in this paper. A reference model is used to generate an ideal motor angle that can guarantee the desired performance, and then, a sliding-mode control is used to track the desired motor angle. This reference model is built using a dynamic mechanical EPAS model, which is driven by the driver torque, the road reaction torque, and the desired assist torque. To implement the reference model with a minimum of sensors, a sliding-mode observer with unknown inputs and robust differentiators are employed to estimate the driver torque, the road reaction torque, and the system´s states. With the proposed control strategy, there is no need for different algorithms, rules for switching between these algorithms, or fine-tuning of several parameters. In addition, our strategy improves system performance and robustness and reduces costs. The simulation results show that the proposed control structure can satisfy the desired performance.
Keywords :
cost reduction; electric vehicles; observers; steering systems; variable structure systems; EPAS systems; control strategy; cost reduction; dynamic mechanical EPAS model; electric-power-assisted steering system; free-control performance; motor angle; robust differentiators; sliding-mode control; sliding-mode observer; steering wheel returnability; system performance; torque commands; DC motors; Roads; Robustness; Torque; Vehicles; Vibrations; Wheels; Electric-power-assisted steering (EPAS); observer with unknown inputs; reference model; robust differentiators; sliding mode;
fLanguage :
English
Journal_Title :
Vehicular Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9545
Type :
jour
DOI :
10.1109/TVT.2012.2209689
Filename :
6247520
Link To Document :
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