1) Yes. Using a lower step-length will work (at the price of increased computational load). An alternative would be to generated input with rounded departure times and extrapolated departPosition (a manual solution to https://github.com/eclipse/sumo/issues/4277).
2) Tau is not rounded. If it is lower than action step length, vehicle safety is compromised. Am Mo., 9. Sept. 2019 um 15:32 Uhr schrieb Mohsen Rahmati < [email protected]>: > Thank you for your help. > > Actually, I'm looking for proper parameters that have the most effect on > my results, in order to use them in the calibration process. my problem is > not a single purpose, so when I try to fit headway with real data, I also > should take care of other indicators such as average speed and etc. this is > why I change SUMO parameters with a reasonable step to see their effects on > my indicators. this is a sample of my simulation scenario: > https://filebin.net/ur65tc7o7yxvgftg/SUMO.zip?t=t90azruf > > 1) how should I configure SUMO, in order to be able to use sub-second > departure time? setting step-length to 0.1s could solve the problem? > 2) if I use tau smaller than action-step-length, is tau parameters rounded > to the nearest multiple of action-step-length or not? > > > With Best Regards, > Mohsen > > On Mon, Sep 9, 2019 at 5:10 PM Jakob Erdmann <[email protected]> > wrote: > >> I'm not quite sure how you compute your "absolute magnitude of mean >> difference". Possibly it is invariant to a constant headway change by all >> vehicles. In this case you should use a tau distribution instead of setting >> the same tau for all vehicles. See >> https://sumo.dlr.de/wiki/Tools/Misc#createVehTypeDistributions.py >> >> 1) the departTime is rounded down (e.g. depart 1.7 actually departs at >> time 1) >> 2) the speed adapts to the safe one. If there is no safe speed, insertion >> is delayed. >> 3) >> https://sumo.dlr.de/wiki/Simulation/VehicleInsertion#Insertion_.28Departure.29 >> >> regards, >> Jakob >> >> Am Mo., 9. Sept. 2019 um 14:01 Uhr schrieb Mohsen Rahmati < >> [email protected]>: >> >>> Thanks, Jakob. >>> the plots were I mentioned before: >>> https://filebin.net/bhvv8wow4cx0e9x8/Headway.zip?t=h3x55hiu >>> as you can see in the plots, tau was not effective to the mean headway. >>> (all other parameters left at their SUMO default values) >>> >>> >>> I have real data aggregated with a time resolution of 5 minutes, so the >>> exact time pass of vehicles in every 5 minutes is unknown to me. >>> in order to generate vehicles in the simulation scenario, I use >>> exponential distribution for the departure time of each vehicle. (I've >>> tried some distributions and exponential seems to work relatively better >>> than others) >>> >>> now my questions are: >>> >>> 1) by leaving step-length, action-step-length and tau at their default >>> values, what would happen if I use a subsecond time for the departure value >>> of vehicles (for e.g, the first vehicle depart at 1.2s and the second one >>> depart at 1.7s)? dose SUMO take care of that? >>> >>> 2) I use departLane="best" and departSpeed="max", what would happen if >>> the departure time isn't safe? the departure time is delayed or the speed >>> adapts to the safe one? >>> >>> 3) also, what is a safe situation in vehicles generation? the distance >>> greater than the minGap and the headway greater than the tau or you mean >>> something else by stating safe situation? >>> >>> With Best Regards, >>> Mohsen >>> >>> >>> On Mon, Sep 9, 2019 at 1:47 PM Jakob Erdmann <[email protected]> >>> wrote: >>> >>>> Your plot attachments are missing (possibly blocked by the mailing >>>> list). >>>> Mean headway is mostly influenced by the 'tau' parameter. >>>> However, it also depends on the desired speeds (speedFactor, speedDev) >>>> and traffic density: >>>> - if all vehicles have the exact same desired speed (speedDev= 0) then >>>> they will never close the gap to their leader and the headways are fully >>>> determined by the insertion procedure. >>>> - if the desired speeds vary and the density is high, then most >>>> vehicles will be in a queue following a slower leader with headways >>>> determined by tau >>>> - if the desired speeds vary and the density is low, then the headways >>>> are determined by insertion as well as the width of the speed distribution >>>> (and of course tau) >>>> >>>> Am Sa., 7. Sept. 2019 um 20:12 Uhr schrieb Mohsen Rahmati < >>>> [email protected]>: >>>> >>>>> Hello, >>>>> I'm working on calibrating a highway section based on real data >>>>> gathered from detectors. >>>>> I've changed 12 parameters* in car-following and lane-changing model >>>>> to decrease the "Absolute Magnitude of Mead Headway Difference" but it >>>>> seems none of them works. Plots were attached. >>>>> I wonder if you could introduce me the parameter that has the most >>>>> effect on mean headway? >>>>> >>>>> by the way: >>>>> SUMO version: 1.3.1 >>>>> car-following model: KraussPS >>>>> lane-changing model: LC2013 >>>>> >>>>> Note*: the effect of simultaneous change of parameters was not >>>>> considered. so by changing a single parameter, all other parameters were >>>>> left at their default values. >>>>> >>>>> >>>>> With Best Regards, >>>>> Mohsen >>>>> _______________________________________________ >>>>> sumo-user mailing list >>>>> [email protected] >>>>> To change your delivery options, retrieve your password, or >>>>> unsubscribe from this list, visit >>>>> https://www.eclipse.org/mailman/listinfo/sumo-user >>>>> >>>> _______________________________________________ >>>> sumo-user mailing list >>>> [email protected] >>>> To change your delivery options, retrieve your password, or unsubscribe >>>> from this list, visit >>>> https://www.eclipse.org/mailman/listinfo/sumo-user >>>> >>> _______________________________________________ >>> sumo-user mailing list >>> [email protected] >>> To change your delivery options, retrieve your password, or unsubscribe >>> from this list, visit >>> https://www.eclipse.org/mailman/listinfo/sumo-user >>> >> _______________________________________________ >> sumo-user mailing list >> [email protected] >> To change your delivery options, retrieve your password, or unsubscribe >> from this list, visit >> https://www.eclipse.org/mailman/listinfo/sumo-user >> > _______________________________________________ > sumo-user mailing list > [email protected] > To change your delivery options, retrieve your password, or unsubscribe > from this list, visit > https://www.eclipse.org/mailman/listinfo/sumo-user >
_______________________________________________ sumo-user mailing list [email protected] To change your delivery options, retrieve your password, or unsubscribe from this list, visit https://www.eclipse.org/mailman/listinfo/sumo-user
