| Re: [sumo-user] Questions about the content of SUMO ssm output file |
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Hi Lan, The velocity is a vector – a pair (dx,dy) per time step. If you are interested in the speed, you have to take the vector’s length. That will give you the value
in m/s. Best, Leo Von: sumo-user-bounces@xxxxxxxxxxx [mailto:sumo-user-bounces@xxxxxxxxxxx]
Im Auftrag von Emily Z. Dear SUMO community, My work uses ssm devices equipted to vehicles to record the conflict events. For the contents of output file, I cannot fully understand the meaning of ego and feo velocities. The below is the example output content given in your wiki webpage.
Could you please expalin the following questions? 1) What is the meaning for the negative velocity value? Why do both the positive and negative velocity exist in a same conflict output? 2) What is the unit of velocity? 3) Why does the velocity value jump in each second? Why are there always a 0.00 point between two positive/negative velocity values. For example the feoVelocity changes from 13.02 to 0.00 and then from 0.00 to 12.57. <conflict begin="6.50" end="13.90" ego="ego1" foe="foe1">
<timeSpan values="6.50 6.60 6.70 6.80 6.90 7.00 7.10 ..."/>
<typeSpan values="10 10 10 10 10 10 10 ..."/>
<egoPosition values="98.35,61.20 98.35,60.20 98.35,59.25 ..."/>
<egoVelocity values="0.00,-10.23 0.00,-9.78 0.00,-9.33 ..."/>
<foePosition values="76.31,48.35 77.59,48.35 78.82,48.35 ..."/>
<foeVelocity values="13.02,0.00 12.57,0.00 12.12,0.00 ..."/>
<conflictPoint values="99.23,49.46 99.23,49.46 99.23,49.46 ..."/>
<TTCSpan values="1.78 1.74 1.70 1.67 1.63 1.60 1.56 ..."/>
<minTTC time="7.40" position="99.23,49.46" type="10" value="1.48"/>
<DRACSpan values="3.66 3.61 3.56 3.50 3.44 3.37 3.30 ..."/>
<maxDRAC time="6.50" position="99.23,49.46" type="10"
value="3.66"/>
<PET time="9.42" position="99.23,49.46" type="17" value="0.72"/>
</conflict>
Your reply would be very valuable to my current research. Thank you for your help! Best regards, Lan |