IEDC-2010 Conference Proceedings (Download ... - NED University

v f
(km/h)
p cr
(veh/km/lane)
a
z
ln( V ) 18
1
v c c
3,..., N 2] 19
* T a T
( ) [ln(
f
), ( ) ,
1,..., N
] [
1, 2,
cr
And
a
[1, , ( t 1), , ( t N )]
a
T
( t ) z ( t ) ( t 1) ( t 1) 21
20
Where ( t 1) is the last estimation of the parameters.
60
55
50
critical density
critical density estimation
45
40
35
30
25
20
15
10
5
0 0.5 1 1.5 2 2.5 3 3.5 4
time(hour)
Figure 10. On-line estimation of critical density based on ELS method
220
200
free speed
free speed estimation
180
160
140
120
100
80
60
0 0.5 1 1.5 2 2.5 3 3.5 4
time(hour)
Figure 11. On-line estimation of free speed based on ELS method
The on-line estimation of the model parameters based on extended least square are shown in Figures 10,
11 and 12. The simulation results are summarized in Fig. 13. Performance index for adaptive estimator is
0.0865.
For evaluating the performance of adaptive estimator, like non-adaptive estimator, it is assumed that the
real free speed drops from 120 km/h to 100 km/h after about one hour and stays at this level until the end
of the simulation.
2.5
exponent
exponent estimation
2
1.5
1
0.5
0 0.5 1 1.5 2 2.5 3 3.5 4
time(hour)
Figure 12. On-line estimation of exponent based on ELS method
Proceedings of IEDC 2010, 1-3 July, 2010
324
IEDC-333-073