Simple python script which allow you start multiple SITL vehicles.
First start can take time.
This open vehicles from port 14551 up, and instances from 1 up.
Move sim_vehicle_mod.py and sim_vehicle_multiple.py to your ardupilot sim_vehicle folder.
Example: /vagrant/ardupilot/Tools/autotest/
run command: python sim_vehicle_multiple.py
Parameters:
-l LOCATION, [x,y,z,heading]
-v FRAME, [ArduPlane, ArduCopter etc..]
-a AMOUNT, amount of vehicles