Traci Variable Speed Signs - how to synchronize adjustment?

[juanwulu]

Hello everyone. I'm new to SUMO community and recently while working on one of my project, I've been trying to change variable speed signs randomly with a fixed step size. here are the test_codes:

from future import print_function
import numpy as np
import sys, os, time
import traci
from sumolib import checkBinary
import xml.etree.ElementTree as ET
from xml.dom import minidom
if 'SUMO_HOME' in os.environ:
tools = os.path.join(os.environ['SUMO_HOME'],'tools')
sys.path.append(tools)
else:
sys.exit("please declare environment variable 'SUMO_HOME'")

projectFile = './Project/'
sumoBinary = "sumo-gui"
seeds = 20190505
traci.start([sumoBinary, '-c', projectFile + 'ramp.sumo.cfg','--start','--seed',
str(seeds), '--emergencydecel.warning-threshold', '1.1', '--quit-on-end'], label='training')
scenario = traci.getConnection('training')

def vsl(time,speed):
tree =ET.parse(projectFile+'vsl.def.xml')
root = tree.getroot()
for element in root.findall('step'):
element.set('speed',str(speed))
element.set('time', str(time))
tree.write(projectFile+'vsl.def.xml')
return

for i in range(9300):
if i % 100 == 0:
step = traci.simulation.getTime()
vsl(int(step)+1, 8.33 + np.random.rand()*(11.11-8.33))
traci.simulationStep()
scenario.close()

However, the signs won't change although the vsl.def.xml has already changed. How can i fix this problem? Thx!

[namdre]

variableSpeedSigns (and all other things from an additional-file) are loaded once at the start of the simulation so updating them afterwards has no effect.
However, you can simply call traci.edge.setMaxSpeed (or traci.lane.setMaxSpeed) to modify speed limits dynamically.

[gyq18]

Does "traci.edge.setMaxSpeed" set a new maximum speed (in m/s) for all lanes of the edge? If I want to set two lanes of an edge with different speed limit, how can I achive this?

[namdre]

edge.setMaxSpeed is applied to all lanes. The change lanes individually, use traci.lane.setMaxSpeed

[gyq18]

thanks a lot!

[Jinbo0201]

Thanks!