Page 373 - Mechatronics for Safety, Security and Dependability in a New Era

Ch72-I044963.fm Page 357 Tuesday, August 1, 2006 9:53 PM
Page 357
1, 2006
9:53 PM
Tuesday, August
Ch72-I044963.fm
357
357
Constant a
Constant a
Constant b
12 0.25
1 0.20
a
e 8 b

u l e u 0.15
V 6 l a
a
4 V 0.10
2 0.05
0 0.00
2.0
1.5
0. 0. 1.0 1.5 2.0 2.5 3.0 3.5 0.0 1.5 3.0 3.5
2.5
2.5
2.0
Current, A 0. 1.0 1.5 2.0 2.5 3.0
Current, A
Current , A
Current, A
(a) (b)
(a)
(b)
Figure 4: Analysis of (a) Constant a and (b) constant b.
EDC
EDC
m 35000
0.0 A
/ 0.0 A
s
N 30000 -»- 0.5 A
0.5 A

,
f 25000 -4 - 1.0 A
1.0 A
.
f
e -X- 1.5A
1.5 A
C 20000
o
2.0 A
-* - 2.0 A
n 15000
g
2.5 A
i - « - 2.5 A
p 3.0 A
m 10000 -+" 3.0A
a 5000
D

.
E 0

0.03
0.00 0.01 0.02 0.03
0.00
0.02
0.01
Displacement, m
Displacement, m
(b)
(a)
(a) (b)
Figure 5: (a) Equivalent Damping Coefficient analysis, (b) Quarter suspension car model.
Simulation of MR Suspension System
The use of computational software has played an important role in design. Computational techniques
are being used to complement, reinforce and specially to reduce time and money spent on experiments
and practical applications. Part one. Adjustment of the damper resistance according to constitutive
model. A quarter suspension car has been designed in ADAMSVIEW software, as shown in Figure 5b,
based on a commercial car. The analysis of the suspension was done by simulating a collision between
the car and an object at a velocity of 16.6 m/s. Once the design is completed, the damper coefficient
value was modified by introducing a set of data points, which permits the software, based on an
internal function, interpolate the discrete data. Such interpolation represents the EDC equation. Part
two. Damper displacements at different virtual road conditions. According with the results obtained
from the comparative analysis, a strong difference behavior between passive and semi-active
suspension systems exist. The passive system shows a drastic change in the damper deformation and
chassis displacement, meanwhile the semi-active system shows an adaptive behavior according with
the respective damper displacement. When the MR damper is under a low magnetic field the
suspension system presents a smoother reaction compared with that of the passive suspension and a
higher magnetic field. According with the results obtained from the analysis, it has been demonstrated
that the equation obtained for the ECD made possible an appropriate response of the suspension
system based on the magnetic field induced. Once the behavior of the MR suspension system has been
demonstrated, a control algorithm is necessary to be developed and implemented, so that, the system
responds according to the road conditions and the comfort required by the human being.