Hello, I copied the calculation of brake gap from: https://github.com/eclipse/sumo/blob/08766930f4b3d3df95aa5cfcf92bae0358724710/src/microsim/cfmodels/MSCFModel.cpp#L89 line by line:
STEP_LENGTH = 1 def brakeGapEuler(speed, decel, headwayTime): speedReduction = STEP_LENGTH * decel steps = int(speed/speedReduction) return STEP_LENGTH * (steps * speed - speedReduction * steps * (steps + 1) / 2) + speed * headwayTime In the original definition, ACCEL2SPEED is defined in https://github.com/eclipse/sumo/blob/9bab618a12a49ae925954e23c2386dd67b7717ea/src/utils/common/SUMOTime.h#L49 where the relevant lines to calculate TS in the same file: // the step length in ms > extern SUMOTime DELTA_T; > // the step length in seconds as double > #define TS (static_cast<double>(DELTA_T/1000.)) would mean that if my step length is the default value of 1 second, DELTA_T will hold the same value in milliseconds (ms), that is, *1000 ms*? And hence, TS will hold a value of 1000/1000 = *1s. *So the first line *const double speedReduction = ACCEL2SPEED(decel); *will be a *speedReduction = decel * 1, *that is, the value of maximum deceleration ability of a vehicle? I was told that in general, *egoSpeed * tau + egoBrakeGap = secureGap + leaderBrakeGap* so I am trying to verify my calculation of brake gap using that (Since there is no other way to get brakeGap using TraCI?) # egoSpeed * tau + egoBrakeGap = secureGap + leaderBrakeGap egoBrakeGap = brakeGapEuler(speed=speed, decel=traci.vehicle.getDecel(vh), headwayTime=1) leaderBrakeGap = brakeGapEuler(speed=traci.vehicle.getSpeed(rel_veh), decel= traci.vehicle.getDecel(rel_veh), headwayTime=1) print('{} * {} + {} = {} + {}'.format(speed, 1, egoBrakeGap, secureGap, leaderBrakeGap)) that prints: 3.2317 * 1 + 3.2317 = 0.15779999999999994 + 10.6478 which is *False*. I am not sure where I am going wrong here in this case. >From my understanding headwayTime = tau = 1 second? Please advise. Thank you. Sincerely, Hriday
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