see https://github.com/eclipse/sumo/blob/de92290f118f38780aaf9b809a415ef981779b50/src/microsim/MSVehicle.cpp#L5787-L5848
Am Mo., 5. Juni 2023 um 16:24 Uhr schrieb Soumya Sharma via sumo-user < sumo-user@eclipse.org>: > Hi Jakob, > Thanks for the information, that is very helpful. > > Also, in one of your previous emails, you mentioned: > "The default look-ahead distance for strategic decision has a maximum > range of about 3000m. You can reduce this distance by setting vType > attribute 'lcStrategic' to a value in [0, 1[. " > > Where does this 3000m distance come from? is it the same as laDist? and > where can I find these default values and the code corresponding to > defaults? > My goal is to understand how the look-ahead distance of a vehicle > changes with changing parameters like "lcStrategic" and "lcLookaheadLeft", > "lcAssertive" and "lcSpeedGain". > > Thanks! > > On Mon, Jun 5, 2023 at 7:57 AM Jakob Erdmann <namdre.s...@gmail.com> > wrote: > >> - All these attributes are factors and thus unitless >> - in the laDist computation, the value of LOOK_FORWARD is the time (10s) >> which is then scaled >> >> >> Am So., 4. Juni 2023 um 04:24 Uhr schrieb Soumya Sharma via sumo-user < >> sumo-user@eclipse.org>: >> >>> Hello, >>> I am trying to conduct a sensitivity analysis of car-following and >>> lane-changing parameters in SUMO for hypothetical freeway segments (basic >>> and weaving). I tried changing headway values (car-following) and >>> lcStrategic values (lane-changing) for a basic segment. I used lcStrategic >>> values of 500, 1000, and 1500 for trucks in simulations (length = 15.25m). >>> My trucks are using the CACC model. >>> The two metrics I am interested in are the travel rates (secs/ mi) by >>> vehicle type and the number of lane changes per vehicle type. I found that >>> there was no change in travel rate and a number of lane changes when I >>> changed the value of lcStrategic to 500, 1000, and 1500. I don't understand >>> why there was no effect of changing the parameter values. >>> Next, I want to look into other parameters like "lcLookaheadLeft", >>> "lcAssertive" and "lcSpeedGain". >>> >>> *Question*: I would like to understand the units of the parameters >>> "lcStrategic" and "lcLookaheadLeft", "lcAssertive" and "lcSpeedGain". >>> >>> The SUMO documentation says: >>> >>> 1. lcStrategic: The eagerness for performing strategic lane >>> changing. Higher values result in earlier lane-changing. default: 1.0, >>> range [0-inf), -1 A value of 0 sets the lookahead-distance to 0 >>> (vehicles can still change at the end of their lane) whereas -1 disables >>> strategic changing completely. >>> 2. lcLookaheadLeft: Factor for configuring the strategic lookahead >>> distance when a change to the left is necessary (relative to right >>> lookahead). default: 2.0, range [0-inf) >>> 3. lcAssertive: Willingness to accept lower front and rear gaps on >>> the target lane. The required gap is divided by this value. default: 1, >>> range: positive reals >>> 4. lcSpeedGain: The eagerness for performing lane changing to gain >>> speed. Higher values result in more lane-changing. default: 1.0, range >>> [0-inf) >>> >>> These definitions don't mention any units explicitly, are they all >>> factors? i.e. unitless or are some of them in meters and some unitless? >>> >>> I was checking the code >>> <https://github.com/eclipse/sumo/blob/main/src/microsim/lcmodels/MSLCM_LC2013.cpp#L1850>for >>> LC2013 and found that look ahead distance (laDist) is being >>> calculated as follows: >>> >>> laDist = myLookAheadSpeed * LOOK_FORWARD * myStrategicParam * (right ? 1 >>> : myLookaheadLeft); >>> >>> >>> If this is how the look-ahead distance for a vehicle is calculated when >>> making lane-changing decisions, then both lcLookaheadLeft and >>> lcStrategic specified will be used to calculate laDist but I don't know >>> what what the units of any of these parameters are. For laDist to be in >>> distance units, speed would be multiplied by time here. >>> >>> Please share any information that is available as it would help me >>> understand my results better. >>> >>> Thanks, >>> Soumya. >>> _______________________________________________ >>> sumo-user mailing list >>> sumo-user@eclipse.org >>> To unsubscribe from this list, visit >>> https://www.eclipse.org/mailman/listinfo/sumo-user >>> >> _______________________________________________ >> sumo-user mailing list >> sumo-user@eclipse.org >> To unsubscribe from this list, visit >> https://www.eclipse.org/mailman/listinfo/sumo-user >> > > > -- > Thank you, > Soumya Sharma > > _______________________________________________ > sumo-user mailing list > sumo-user@eclipse.org > To unsubscribe from this list, visit > https://www.eclipse.org/mailman/listinfo/sumo-user >
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