This paper presents a novel observer-based analytical redundancy for a steer-by-wire (SBW) system. In order to achieve high level of reliability for a By-Wire system, double, triple, or even quadruple redundant sensors, actuators, communication networks, and controllers are needed. But this added hardware increases the overall cost of the vehicle. This paper utilizes a novel analytical redundancy methodology to reduce the total number of redundant road-wheel angle (RWA) sensors in a triply redundant RWA-based SBW system, while maintaining a high level of reliability. The self-aligning torque at road-tire interface due to the steering dynamics has been modeled as a function of the linear vehicle states. A full state observer was designed using the combined model of the vehicle and SBW system to estimate the vehicle body side slip angle. The steering angle was then estimated from the observed and measured states of the vehicle (body side slip angle and yaw rate) as well as the current input to the SBW electric motor(s). With at least two physical road-wheel angle sensors and the analytical estimation of the RWA value (which replaces the third physical sensor), a fault detection and isolation (FDI) algorithm was developed using a majority voting scheme. The FDI algorithm was then used to detect faulty sensor(s) in order to maintain safe drivability. The proposed analytical redundancy based fault detection & isolation algorithms and the linearized vehicle model were modeled in SIMULINK. Simulation of the proposed algorithm was performed for both single and multiple sensor faults. Simulation results show that the proposed analytical redundancy based fault detection and isolation algorithm provides the same level of fault tolerance as in an SBW system with full hardware redundancy against single point failures.

1.
Frauzen, S., “Safety and usability benefits of steer-by-wire systems”, Proceedings of the 26th International Symposium on Automotive Technology and Automation, Sep 13-17, Aachen, Germany, Road and Vehicle Safety, 1993, p 63.
2.
Isermann
R.
,
Schwarz
R.
, and
Stolzl
S.
, “
Fault-Tolerant Drive-By-Wire Systems
”,
IEEE Control Systems Magazine
, v
22
, n
5
, October,
2002
, p
64
81
.
3.
Isermann
R.
, “
Diagnosis Methods for Electronic Controlled Vehicles
”,
Vehicle System Dynamics
, v
36
, n
2–3
, September,
2001
, p
77
117
.
4.
Zheng, B., Altemare, C., and Anwar, S., “Fault Tolerant Steer-By-Wire Road Wheel Control System”, American Control Conference, Portland, Oregon, June 8-10, 2005.
5.
Muldoon
S. E.
,
Kowalczyk
M.
, and
Shen
J.
, “
Vehicle Fault Diagnostics Using a Sensor Fusion Approach
”,
Proceedings of IEEE Sensors
, v
1
, n
2
,
2002
, p
1591
1596
.
6.
Gao, Y. and Durrant-Whyte, H.F., “Multi-Sensor Fault Detection and Diagnosis using Combined Qualitative and Quantitative Techniques”, IEEE International Conference on Multisensor Fusion and Integration for Intelligent Systems, 1994, p 43-50.
7.
You, S. and Jalics, L., “Hierarchical Component-based Fault Diagnostics for By-Wire Systems”, SAE Technical Paper Series 2004-01-0285, 2004.
8.
Stanek
M.
,
Morari
M.
, and
Frohlich
K.
, “
Model-Aided Diagnosis: An Inexpensive Combination of Model-Based and Case-Based Condition Assessment
”,
IEEE Transactions on Systems, Man, and Cybernetics Part C: Applications and Reviews
, v
31
, n
2
, May,
2001
, p
137
145
.
9.
Rengaswamy
R.
,
Mylaraswamy
D.
,
Arzen
K. E.
, and
Venkatasubramanian
V.
, “
A Comparison of Model-Based and Neural Network-Based Diagnosis Methods
”,
Engineering Applications of Artificial Intelligence
, V
14
, n
6
, December,
2001
, p
805
818
.
10.
Hashimoto
M.
,
Kawashima
H.
, and
Oba
F.
, “
A Multi-Model Based Fault Detection and Diagnosis of Internal Sensor for Mobile Robot
”,
IEEE International Conference on Intelligent Robots and Systems
, v
4
,
2003
, p
3787
3792
.
11.
Wernz, A. and Kroschel, K., “Instrument Fault Detection and Identification Based on Analytical Redundancy”, IFAC Fault Detection, Supervision and Safety for Technical Processes, Baden-Baden, Germany, 1991.
12.
Venkateswaran
N.
,
Siva
M. S.
, and
Goel
P. S.
, “
Analytical redundancy based fault detection of gyroscopes in spacecraft applications
”,
Acta Astronautica
, v.
50
, n.
9
,
2002
, pp
535
545
.
13.
Suzuki
H.
,
Kawahara
T.
,
Matsumoto
S.
,
Ikeda
Y.
,
Nakagawa
H.
, and
Matsuda
R.
, “
Fault diagnosis of space vehicle guidance and control systems using analytical redundancy
”,
Space Technology
, v.
19
, n.
3–4
,
1999
, pp.
173
178
.
14.
Dong
Y.
and
Hongyue
Z.
, “
Optimal design of robust analytical redundancy for a redundant strapdown inertial navigation system
”,
Control Engineering Practice
, v.
4
, n.
12
,
1996
, pp.
1747
1752
.
15.
Kelly, R.W., “Application of analytical redundancy to the detection of sensor faults on a turbofan engine”, ASME Int’l Gas Turbine and Aeroengine Congress & Exposition, Birmingham, UK, June 10–13, 1996, pp. 1–8.
16.
Hahn, J. O., You, S. H., Cho, Y. M., Kang, S., and Lee, K. I., “Fault Diagnostics in the Differential Brake Control System Using the Analytical Redundancy Technique”, Proceedings of the 42nd IEEE Conference on Decision and Control, Maui, Hawaii USA, December 2003.
17.
Anwar
S.
, “
Generalized Predictive Control of Yaw Dynamics of a Hybrid Brake-By-Wire Equipped Vehicle
”,
International Journal of Mechatronics
, v
15
, November
2005
, pp.
1089
1108
.
18.
Gadda, C.D., Yih, P., and Gerdes, J.C., “Incorporating a Model of Vehicle Dynamics in a Diagnostic System for Steer-By-Wire Vehicle”, Proceedings of the International Symposium on Advanced Vehicle Control (AVEC), Arnhem, The Netherlands, 2004.
19.
Yih, P. and Gerdes, J. C. Steer-by-wire for vehicle state estimation and control. Proceedings of the International Symposium on Advanced Vehicle Control (AVEC), Arnhem, The Netherlands (2004).
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