Re: [sumo-user] some questions about rerouting in SUMO_rerouting algorit

[Jane Cheung <cheung180515@xxxxxxxxx>]

Jakob,

Thanks for your reply!

Based on your reply I read the document to find a way to generate rou.xml from trips.xml

( https://sumo.dlr.de/docs/duarouter.html). The document suggests to use the duarouter.exe to do what I want, and I also found tools ( https://sumo.dlr.de/docs/Tools/Assign.html ) can also be used as alternative methods to generate rou.xml.

Then, I have a little confusion about the relationship between duarouter.exe, dua-iterate.py and on-shot.py。

1) the relationship between duarouter.exe and dua-Iterate.py

The relationship in my understanding is illustrated below:

Assume the simulation begin--time is  0 and end-time is 3600.

Duarouter.exe will use the travel time of each edge (free-flow speed) as the effort or weight in the shortest route algorithm to generate pre-defined routes for vehicles before begin-time=0, and routes would not be updated during the simulation period(=3600s)。Actual trave time of edges would be generated as the results. When calling dua-iterate.py, duarouter.exe will run as the sub-function to generate the actual travel time of each edge, and next iteration of dua-Iterate.py will run shortest route algorithm using the generated travel time.

 2) the relationship between dua-Iterate.py  and one-shot.py

The travel time of each edge is updated after simulation in dua-Iterate.py，but updated in simulation in each given travel-time updating interval in one-shot.py as shown below

Appreciated your help to correct my wrong understanding and looking forward to your reply.

Best,

Jane

On Wed, Sep 2, 2020 at 2:29 PM Jane Cheung <cheung180515@xxxxxxxxx> wrote:

Dear all, 

I have defined the configuration in .sumocfg as below:

<routing>
        <device.rerouting.probability value="-1"/>
        <device.rerouting.period value="300"/>
        <device.rerouting.pre-period value="300"/>
    </routing>

(1)

my question is 

 "-1'' means no vehicles in my simulation could change their route after departing? Does it mean the other two commands are useless with <device.rerouting?probability value="-1"/> ?

If I set the <device.rerouting.probability value="1"/>,   all the vehicles could change their route to the faster in every 300s?

(2)

If my simuation duration is 3600s(1h) and I set the

                    <device.rerouting.probability value="1"/>,    

                   <device.rerouting.period value="75000000000000000"/>  

                   <device.rerouting.pre-period value=" 75000000000000000 "/>  

all the vehicles can change to the fastest route and would not change to the fastest one in my simulation as I had set the rerouting period is  75000000000000000? And vehicles could change to the fastest route when currenttime = 75000000000000001 if I had set the <end valute= "75000000000000001">?

(3) 

if my simulation period is 3600, and the pre-period rerouting value was set to   <device.rerouting.pre-period value="300"/>

<device.rerouting.period value="75000000000000000"/>   

 all the vehicles will be loaded in my simulation would check the fastest route for themself every 300s before departure? The lastest fastest route of one vehicle will be chosen as its route during the whole simulation and would not change their route during the simulation as I set the  <device.rerouting.period value="75000000000000000"/>   ?

(4)  

if I  set the rerouting command as 

  <routing>
        <device.rerouting.probability value="1"/>
        <device.rerouting.period value="300"/>
        <device.rerouting.pre-period value="300"/>
    </routing> 

 

What‘s the difference betwwen using  <route-files value="cross0.trips.xml"/> (1.sumocfg)and  <route-files value="cross0.route.xml"/>( 2.sumocfg   )

the mean travel time in 1.sumocfg is shorter than 2.sumocfg. 

So, why mean travel time is shorter in 1.sumocfg? how do vehicles in 1.sumocfg decide the route? And which route one vehicle would choose before it is going to depart?

Best regard,

Jane Cheung