Simulation/Output/SSM Device

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Revision as of 12:35, 26 July 2017 by Leo (talk | contribs) (Parameters)
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Equipping vehicles

A vehicle can be equipped with an SSM Device which logs the conflicts of the vehicle and other traffic participants (currently only vehicles) and corresponding safety surrogate measures. To attach an SSM device to a vehicle, the standard device-equipment procedures can be applied using <device name>=ssm.

For instance, a single vehicle can be equipped (with a device parametrized by default values) as in the following minimal example

<routes>
    ...
    <vehicle id="v0" route="route0" depart="0">
        <param key="has.ssm.device" value="true"/>
    </vehicle>
    ....
</routes>

The SSM device generates an output file (one for each vehicle named ssm_<vehicleID>.xml per default, but several vehicles may write to the same file). The top level elements of the generated file are

<conflict begin="<log-begin-time>" end="<log-end-time>" ego="<equipped-vehicleID>" foe="<opponent-vehicleID>"> ... </conflict>.

The detail of information given for each conflict and the criteria to qualify an encounter as a conflict (i.e., produce a corresponding conflict element in the output) can be customized by a number of generic parameters to the vehicle or device, resp.. A full parametrization (redundantly assigning the default values, here) could look as follows:

<routes>
    ...
    <vehicle id="v0" route="route0" depart="0">
        <param key="has.ssm.device" value="true"/>
        <param key="device.ssm.measures" value="TTC DRAC PET"/>
        <param key="device.ssm.thresholds" value="3.0 4.0 2.0"/> 
        <param key="device.ssm.range" value="50.0" />
        <param key="device.ssm.extratime" value="5.0" />
        <param key="device.ssm.file" value="ssm_v0.xml" />
        <param key="device.ssm.trajectories" value="false" />
        <param key="device.ssm.geo value="false" />
    </vehicle>
    ....
</routes>

Parameters

The possible parameters are summarized in the following table

Parameter Type Default Remark
measures list of strings All available SSMs This space-separated list of SSM-identifiers determines, which SSMs are calculated for the equipped vehicle's encounters
thresholds list of floats default thresholds for specified measures This space-separated list of SSM-thresholds determines, which encounters are classified as conflicts (if their measurements exceed a threshold) and thus written to the output file as a <conflict>-element. The thresholds for the available SSMs are: TTC<3.0[s], DRAC>4.0[m/s^2], PET<2.0[s]. This list is required to have the same length as the list of measures if given.
measures list of strings All available SSMs This space-separated list of SSM-identifiers determines, which SSMs are calculated for the equipped vehicle's encounters