Outer-loop Quasi-static State Feedback Output Tracking for a Slung Load System : PX4 SITL Validation

This repo contains the simulation code for quasi-static state feedback output tracking of the outer-loop for a slung load system : PX4 SITL validation.

The code simulates a slung load system with a multirotor UAV running the PX4 autopilot firmware. SITL (Software in the loop) is combined with the Gazebo simulator. The reason for using SITL simulation is to test controller performance using actual PX4 firmware. This ensures the controller is implementable on-board physical autopilots (e.g. Pixhawk 1, etc.) and that simulation results are closer to what are observed in flight testing.

Important Folders and Files

1. Folder containing the module which implements the quasi-static controller: RosControl

2. For installing and running PX4-Gazebo simulator, please refer to: PX4 Gazebo Plugin Suite for MAVLink SITL and HITL

3. SLS Model SDF File: iris_pendulum

Docker Image

A docker image is provided DockerHub. The PX4 code and gazebo simulation code is at /src/PX4-Autopilot and /src/PX4-Autopilot/Tools/sitl_gazebo/ respectively.

Usage

Running the SITL/Gazebo Simulation

1. In order to compile the PX4 code for SITL:

make px4_sitl_default gazebo no_sim=1

When the build is successful, JMAVSim and the PXH shel are launched. In the terminal you should see

______  __   __    ___ 
| ___ \ \ \ / /   /   |
| |_/ /  \ V /   / /| |
|  __/   /   \  / /_| |
| |     / /^\ \ \___  |
\_|     \/   \/     |_/

px4 starting
...
INFO [tone_alarm] home_set
INFO [tone_alarm] neutral
pxh>

2. Start ROS, PX4, and Gazebo:

cd PX4_SITL_664/Tools/sitl_gazebo/ancl_sls
./mavros_script.sh

3. Use QGroundControl to take off.

4. Enable quasi-static controller:

rosrun offboardholy get_states_holy_node
rosrun offboardholy offb_control_holy_node

Debug/Customize Controller

If you run into any problems using the code, please open an issue, or you can email one of us:

• Zifei Jiang zifei3@ualberta.ca
• Alan F.Lynch alan.lynch@ualberta.ca
• Edward Yan ejyan@ualberta.ca

Citing

Acknowledgement

Thanks to the PX4 team and PX4 Gazebo Plugin for their open-source autopilot on which this code is based.

SLS_PX4_SITL