Skip to main content

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [sumo-user] Add vehicles to simulation

It may be more appropriate to query the Flow devs on this. However, if you are missing vehicles in the simulation, you could check for

Am Di., 6. Juni 2023 um 20:49 Uhr schrieb Stefano Bonasera <stefano.bonasera@xxxxxxxxx>:
Hi there,

I am trying to randomly place a finite (and specific) set of vehicles in certain parts of a map network in SUMO using Flow along with the Traci simulator but... without using Flow's inflows() objects.
When running the flow.envs.base.reset()  to reset the sim with a new randomized configuration, one of the vehicles added is missing.

Let network_object = flow.networks.Network(....) derived from Flow. I can confirm it has the correct ID list and initial state configuration (ID, lane_ID, position, velocity) in its fields. When calling Flow reset(), running self.k.kernel_api.vehicle.getIDList() confirms there are missing vehicles relative to network_object.vehicles.ids. After detecting this discrepancy, Flow errors out.

The error message form is:

  File "~/", line N, in reset
    return super().reset()
  File "/tmp/ucrl/flow/envs/", line M, in reset
    raise FatalFlowError(msg=msg)
Not enough vehicles have spawned! Bad start?
Missing vehicles / initial state:
- vehicle_X : ('vehicle_type_X', 'custom_road_name', lane_id, position, velocity)
A hack that seems to help is adding the following code inside of the missing vehicles check before returning the observation vector to the simulation environment:

  # check to make sure all vehicles have been spawned
  if len(network_object.initial_ids) > len(self.k.kernel_api.vehicle.getIDList()):
      missing_vehicles = list(set(self.initial_ids) - set(initial_ids))
      for mv in missing_vehicles:
          self.k.kernel_api.vehicle.remove(mv)  # FIXME: hack
          type_id, edge, lane_index, pos, speed = self.initial_state[mv]
          # update the information in each kernel to match the current state

I am not sure why the missing vehicle was not added before reaching this part of the code. Is this a problem that others have seen before? Any suggested fixes if we do not want to use Inflows()?

Thanks as always for your time and your help!

sumo-user mailing list
To unsubscribe from this list, visit

Back to the top