This paper presents a semi-active seat suspension with an electrorheological (ER) fluid damper. A cylindrical ER seat damper is devised on the basis of a Bingham model of an arabic gum-based ER fluid and its field-dependent damping characteristics are empirically evaluated. A semi-active seat suspension is then constructed, and the governing equations of motion are derived by treating the driver mass as a parameter uncertainty. A sliding mode controller, which has inherent robustness to system uncertainties, is formulated to attenuate seat vibration due to external excitations. The controller is then experimentally realized, and controlled responses are presented in both time and frequency domains. In addition, a full-car model consisting of primary, cabin, and seat suspensions is established, and a hardware-in-the-loop simulation is undertaken to demonstrate a practical feasibility of the proposed seat suspension system showing ride comfort quality under various road conditions.

1.
Queslati, F., and Sankar, S., 1992, “Performance of a Fail-Safe Active Suspension With Limited State Feedback for Improved Ride Quality and Reduced Pavement Loading in Heavy Vehicles,” SAE Paper, No. 922474, pp. 796–804.
2.
Reynolds, H. M., 1993, Automotive Ergonomics, Taylor and Francis Ltd, London, pp. 99–116.
3.
Rakheja
,
S.
,
Afework
,
Y.
, and
Sankar
,
S.
,
1994
, “
An Analytical and Experimental Investigation of the Driver-Seat-Suspension System
,”
Veh. Syst. Dyn.
,
23
, pp.
501
524
.
4.
Shimogo
,
T.
,
Oshinoya
,
Y.
, and
Shinjyo
,
H.
,
1996
, “
Active Suspension of Truck Seat
,”
JSME
62
, pp.
192
198
.
5.
Stein
,
G. J.
,
1997
, “
A Driver’s Seat with Active Suspension of Electro-pneumatic Type
,”
J. Vibr. Acoust.
,
119
, pp.
230
235
.
6.
Karnopp
,
D.
,
Crosby
,
M. J.
, and
Harwood
,
R. A.
,
1974
, “
Vibration Control Using Semi-active Force Generators
,”
ASME J. Eng. Ind.
,
96
(
2
), pp.
619
626
.
7.
Morishita
,
S.
,
Mitsui
,
J.
, and
Kuroda
,
Y.
,
1990
, “
Controllable Shock Absorber as an Application of Electro-rheological Fluid
,”
JSME
56
, pp.
78
84
.0
8.
Petek, N. K., 1995, “Demonstration of an Automotive Semi-active Suspension Using Electrorheological Fluid.” SAE Paper, No. 950586.
9.
Sturk
,
M.
,
Wu
,
X. M.
, and
Wong
,
J. Y.
,
1995
, “
Development and Evaluation of a High Voltage Supply Unit for Electrorheological Fluid Dampers
,”
Veh. Syst. Dyn.
,
24
, pp.
101
121
.
10.
Choi
,
S. B.
,
Choi
,
Y. T.
,
Chang
,
E. G.
,
Han
,
S. J.
, and
Kim
,
C. S.
,
1998
, “
Control Characteristics of a Continuously Variable ER Damper
,”
Mechatronics
,
8
, pp.
143
161
.
11.
Wu
,
X.
, and
Griffin
,
M. J.
,
1997
, “
A Semi-active Control Policy to Reduce the Occurrence and Severity of End-stop Impacts in a Suspension Seat with an Electrorheological Fluid Damper
,”
J. Vibr. Acoust.
,
203
(
5
), pp.
781
793
.
12.
Brooks. D. A., 1997, “High Performance Damping Using Electro-Rheological Fluids,” Proc. of Int. Conf. on ERF, MRS and Their Applications, Yamagata, Japan, pp. 250–251.
13.
International Standard Organization ISO-2631/1, 1985, “Evaluation of Human Exposure to Whole-Body Vibration, Part 1: General Requirements.”
14.
Winslow
,
W. M.
,
1949
, “
Induced Fibration Suspension
,”
J. Appl. Phys.
,
20
, pp.
1137
1140
.
15.
Ginder
,
J. M.
, and
Ceccio
,
S. L.
,
1995
, “
The Effect of Electrical Transients on the Shear Stresses in Electrorheological Fluids
,”
J. Rheol.
,
39
, pp.
211
234
.
16.
Leitmann
,
G.
,
1981
, “
On the Efficiency of Nonlinear Control in Uncertain Linear Systems
,”
ASME J. Dyn. Syst., Meas., Control
,
102
, pp.
95
102
.
17.
Dorling
,
C. M.
, and
Zinober
,
A. S. I.
,
1986
, “
Two Approaches to Hyperplane Design in Multivariable Variable Structure Control Systems
,”
International Journal of Control
,
44
(
1
), pp.
65
82
.
18.
El-ghezawi
,
O. M. E.
,
Zinober
,
A. S. I.
, and
Billings
,
S. A.
,
1983
, “
Analysis and Design of Variable Structure Systems using a Geometric Approach
,”
Int. J. Control
,
38
(
3
), pp.
657
671
.
19.
Gouw, G. J., Rakheja, S., Sankar, S., and Afework, Y., 1990, “Increased Comfort and Safety of Drivers of Off-highway Vehicles using Optimal Seat Suspension,” SAE Paper, No. 901646.
20.
Nigam, N. C., Narayanan, S., 1994, Applications of Random Vibrations, Springer-Verlag, pp. 219–292.
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