1. The error state evolves according to https://en.wikipedia.org/wiki/Ornstein%E2%80%93Uhlenbeck_process The code is in MSDriverState (see OUProcess) Control parameters for the OUProcess are errorTimeScaleCoefficient and errorNoiseIntensityCoefficient as well as awareness (see https://github.com/eclipse/sumo/blob/7ca399daab28139f5a726f557c4593454cb5174a/src/microsim/MSDriverState.cpp#L180-L188 )
2) there is no range limitation 3) a) the error affects gap and speed difference estimation (by default the error coefficients have the same sign which means a driver that overestimates the gap to the leader will also overestimate the leader speed) b) the underlying assumption was that the expected error is 0 (no systematic bias). For the calculation see answer to 1) c) with errorState = 10 the actual difference between real gap and faulty gap is 7.5 * trueGap (with default headwayErrorCoefficient = 0.75) Note: when doing a sample run of the OU-Process a million times with default parameters, the error lies in [-0.85, 0.85] and ~90% of the error states are in [-0.2, 0.2]. regards, Jakob Am Di., 26. Jan. 2021 um 08:20 Uhr schrieb Mehdi Maleki < [email protected]>: > > > Hi, > > > > Regarding the driver state device: > > > > > > > > > > 1. How is the error(t) scaled, do we give input for this? Is this the > same with device.driverstate.errorState? > > > > 1. Default value for speedDifferenceErrorCoefficien is 0.15, what is > the range for this? > > > > > > > > Before, I asked about the definition and range of the > "device.driverstate.errorState" > parameter. The answer that I got was this: ErrorState gives the magnitude > and direction of the relative error in gap estimation. The state tends > toward 0 in the long run but there is no limit to how far it may deviate > from 0. > > > > 1. My questions are: Does it affect only the gap estimation? Why it > tends to zero over the time, does it represent something in real life? With > what rate it tends to zero? (I want to see the mathematical calculation, > for example when I set errorState to 10 how much the real gap and faulty > one are different). > > > > Btw, I have checked "MSDriverState" file but could not find the answer for > my questions. > > > > > > > > Best regards, > > Mehdi > _______________________________________________ > sumo-user mailing list > [email protected] > To unsubscribe from this list, visit > https://www.eclipse.org/mailman/listinfo/sumo-user >
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