SUMO
Simulation of Urban MObility

- Home
- Download
- Documentation
- Wiki
- Trac
- Blog
- Contact
- SF-Project

# Simulation/Output/Multi-Entry Multi-Exit Detectors (E3)

## Instantiating within the Simulation

Multi-Entry/Multi-Exit Detectors have to be defined within an additional file which has to be loaded by the simulation.

The descriptions of Multi-Entry/Multi-Exit Detectors have to include the set of entry- and the set of exit-cross-sections. Due to this, it is not possible to use a single tag to specify a detector. Instead, the description consists of the following parts:

- A beginning tag that describes some global attributes of the detector just as the descriptions of inductive loop detectors and areal detectors do. The format is: <entryExitDetector id="<ID>" file="<OUTPUT_FILE>" freq="<AGGREGATION_TIME>" [timeThreshold="<FLOAT>"] [speedThreshold="<FLOAT>"]>
- A set of tags that describe the detector's entry points in the form: <detEntry lane="<LANE_ID>" pos="<POSITION_ON_LANE>" [friendlyPos="x"]/>
- A set of tags that describe the detector's exit points in the form: <detExit lane="<LANE_ID>" pos="<POSITION_ON_LANE>" [friendlyPos="x"]/>
- A closing tag that must match the opening tag: </entryExitDetector>

The definition

    <entryExitDetector id="e3_1" freq="300" file="./output/e3_1.xml">
       <detEntry lane="myEdge0_0" pos="0"/>
       <detEntry lane="myEdge0_1" pos="0"/>
       <detExit lane="myEdge2_0" pos="0"/>
       <detExit lane="myEdge2_1" pos="0"/>
    </entryExitDetector>

will build a Multi-Entry/Multi-Exit Detector starting at either lane 0 or 1 of the edge called "myEdge0" and end at the same lane of "myEdge2". All values will be computed as the default-value for measures is used and aggregated over a time of 300s. They will be written into the file "e3_1.xml" lying in the subfolder of the folder the configuration was read in/the program has been started within.

## Generated Output

A single data line within the output of a simulated Multi-Entry/Multi-Exit Detector looks as following:<interval begin="<BEGIN_TIME>" end="<END_TIME>" id="<ID>" meanTravelTime="<MEAN_TT>" meanSpeed="<MEAN_SPEED>" meanHaltsPerVehicle="<MEAN_HALT_NUMBER>" vehicleSum="<#VEHICLES>" meanSpeedWithin="<MEAN_SPEED>" meanHaltsPerVehicleWithin="<MEAN_HALT_NUMBER>" meanDurationWithin="<MEAN_HALT_DURATION>" vehicleSumWithin="<#VEHICLES>" meanIntervalSpeedWithin="<MEAN_SPEED>" meanIntervalHaltsPerVehicleWithin="<MEAN_HALT_NUMBER>" meanIntervalDurationWithin="<MEAN_HALT_DURATION>"/>

As for lane area detectors, the measures generated by Multi-Entry/Multi-Exit Detector may be grouped by the way they are computed. The plain measures take only those vehicles into account that have left the detector area within the described interval. Additionally, measures of the vehicles that are still inside the area are generated (postfix "Within"), containing both measures valid for the whole ride through the area and measures made up of only those samples that were collected within the current interval ("...Interval..."). The value are described one by one in the following table.

Name | Type | Description
--- | --- | ---
begin | (simulation) seconds | The first time step the values were collected in
end | (simulation) seconds | The last time step + DELTA_T the values were collected in (may be equal to begin)
id | id | The id of the detector
meanTravelTime | s | The time vehicles needed to pass the area. Averaged over all vehicles that have left the detector during the interval duration.
meanSpeed | m/s | The mean speed of vehicles that have passed the area. Averaged over the interval and vehicles.
meanHaltsPerVehicle | # | The number of halts of vehicles that have passed the area. Averaged over all vehicles that have left the detector during the interval duration.
vehicleSum | # | The number of vehicles that have left the area during the interval.
meanSpeedWithin | m/s | The mean speed of those vehicles that have entered, but not yet left the area. Averaged over the time each vehicle was in the area and vehicles.
meanHaltsPerVehicleWithin | m/s | The mean number of haltings of those vehicles that have entered, but not yet left the area. Averaged over the time each vehicle was in the area and vehicles.
meanDurationWithin | s | The mean duration is within the area of those vehicles that have entered, but not yet left the area. Averaged over the time each vehicle was in the area and vehicles.
vehicleSumWithin | s | The number of vehicles that have entered but not yet left the area.
meanIntervalSpeedWithin | m/s | The mean speed of those vehicles that have entered, but not yet left the area, collected during the written interval. Averaged over the interval and vehicles.
meanIntervalHaltsPerVehicleWithin | # | The number of vehicles that have left the area during the interval, collected during the written interval. Averaged over the interval and vehicles.
meanIntervalDurationWithin | s | The number of vehicles that have left the area during the interval, collected during the written interval. Averaged over the interval and vehicles.

## Further Notes

- Simulated multi-entry/multi-exit detectors can be accessed using TraCI
- You can generate detector definitions automatically. See output tools for more information.

This page was last modified on 24 August 2012, at 08:08.