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4 Sensitivity Analysis
As an example, Figure 4.5 shows the comparison of two simulations at the data point
where each reaches the driving state with a longitudinal acceleration of 1.2 m/s2 and
a lateral acceleration of 1.9 m/s2. The absolute value of the sensitivities is higher for
LQ manoeuvres. This is true for all simulations. This difference between the absolute
values of the sensitivities for LQ and QL manoeuvres increases with higher acceleration
conditions. This indicates that the influence of the longitudinal velocity is mainly re-
sponsible for this effect. Nevertheless, the tendencies are similar, and it leads to the
same conclusion that was drawn for the influence of the longitudinal speed, cf. Section
4.3.2. Thus, this does not limit the comparability of the tendencies, as the absolute
value of the sensitivities is not of interest.
0 0.5 1 1.5
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
Friction Potential ”max
LQ
QL
0 0.5 1 1.5
-1.8
-1.6
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
b
a
x = 1.2 in m/s2,
b
a
y = 1.9 in m/s2
Friction Potential ”max
Figure 4.5.: Comparison of the selected sensitivitiesâvx/â” (left)andâÏfl/â” (right)
versus”max shows similar behaviour for LQ and QL manoeuvres at a longi-
tudinal acceleration of 1.2 m/s2 and a lateral acceleration of 1.9 m/s2.
4.4. Normalisation of sensitivities
The state variables and their sensitivities with respect to”max do not all have the same
units and also vary in their orders of magnitude. To be able to choose the variables that
73
Maximum Tire-Road Friction Coefficient Estimation
- Title
- Maximum Tire-Road Friction Coefficient Estimation
- Author
- Cornelia Lex
- Publisher
- Verlag der Technischen UniversitÀt Graz
- Location
- Graz
- Date
- 2015
- Language
- English
- License
- CC BY-NC-ND 3.0
- ISBN
- 978-3-85125-423-5
- Size
- 21.0 x 29.7 cm
- Pages
- 189
- Category
- Technik