| [sumo-user] Input values for HBEFA4-based model |
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Dear all, I have run a simple scenario of a single vehicle at constant speed (50 km/h speed limit). I then compared the resulting emissions as given by the HBEFA4-based model with a „manual“ calculation using a specific emission factor request from
HBEFA 4.2 using the traffic parameters given by FullOutput. I have attached the results for a petrol passenger car (Euro 6) and diesel passenger car (Euro 6d-temp). The difference is shown with respect to the values produced by SUMO. For instance, a positive
difference would mean that SUMO overestimates a certain pollutant (since the emission factor from HBEFA 4.2 estimates a higher value). It seems that the HBEFA4-based model tends to underestimate PMx but varies for fuel consumption and NOx, depending on the
vehicle class and Euro standard which brings me to my question. According to a previous discussion (https://github.com/eclipse-sumo/sumo/issues/15206), it was mentioned that SUMO takes the emission for a particular vehicle class and emission
type and then uses Lawson-Hanson NNLS method to create emission as a function of speed.
Here are the graphs (https://github.com/eclipse-sumo/sumo/issues/15206#issuecomment-2229146282) which displays 7 distinct lines which seem to correspond
to different road gradients as given in HBEFA 4.2 database (-6, -4, -2, 0, 2, 4 & 6). Which input values are being used for the corresponding points? I was curious since HBEFA 4.2 can not only give „general“ emission factors of an aggregate trafic situation
(including the gradient) but can also produce emission factors for a specific area (rural/urban), level of service, road type (motorway, non-motorway, secondary, etc.) as well as the speed limit which extends the possible combinations. Could the difference
be caused by the input values used in the HBEFA4-based model? Thanks in advance. Warmest regards, Addina |
Attachment:
Diesel Passenger Car Euro 6d-temp.png
Description: Diesel Passenger Car Euro 6d-temp.png
Attachment:
Petrol Passenger Car Euro 6.png
Description: Petrol Passenger Car Euro 6.png
