PX4 Integration

The PX4-Autopilot support is provided by making use of the Control Backends API , and implementing a custom MavlinkBackend which contains a built-in tool to launch and kill PX4 in SITL mode automatically.

To instantiate a MavlinkBackend via Python scripting, consider the following example:

# Import the Mavlink backend module
from pegasus.simulator.logic.backends.mavlink_backend import MavlinkBackend, MavlinkBackendConfig

# Create the multirotor configuration
# In this example we are showing the default parameters that are used if you do not specify them
mavlink_config = MavlinkBackendConfig({"vehicle_id": 0,
    "connection_type": "tcpin",
    "connection_ip": "localhost",
    # The actual port that gets used = "connection_baseport" + "vehicle_id"
    "connection_baseport": 4560,
    "enable_lockstep": True,
    "num_rotors": 4,
    "input_offset": [0.0, 0.0, 0.0, 0.0],
    "input_scaling": [1000.0, 1000.0, 1000.0, 1000.0],
    "zero_position_armed": [100.0, 100.0, 100.0, 100.0],
    "update_rate": 250.0,

    # Settings for automatically launching PX4
    # If px4_autolaunch==False, then "px4_dir" and "px4_vehicle_model" are unused
    "px4_autolaunch": True,
    "px4_dir": "PegasusInterface().px4_path",
    "px4_vehicle_model": "iris",
    })
config_multirotor.backends = [MavlinkBackend(mavlink_config)]

Note

In general, the Pegasus Simulator does not need to know where you have PX4 running to simulate the vehicle and send data through MAVLink . However, if you intend to use the provided PX4 auto-launch feature, you must inform Pegasus Simulator where you have your local install of PX4.

By default, the simulator expects PX4 to be located at ~/PX4-Autopilot directory. You can set the default path for the PX4-Autopilot by either:

  1. Using the GUI of the Pegasus Simulator when operating in extension mode.

    Setting the PX4 path

  2. Use the methods provided by PegasusInterface, i.e:

    from pegasus.simulator.params import SIMULATION_ENVIRONMENTS
from pegasus.simulator.logic.interface.pegasus_interface import PegasusInterface

# Start the Pegasus Interface
pg = PegasusInterface()

# Set the default PX4 installation path used by the simulator
# This will be saved for future runs
pg.set_px4_path("path_to_px4_directory")