# oscillation_ctrl

Repo containing oscillation damping controller for tether missions + instructions how to to set up

Cesar Rodriguez 

cesar.rodriguez@spirirobotics.com

February 2022

Steps to recreate stable PX4 environment + working repo

## 1) Installing ROS Melodic

### SETUP SOURCES.LIST
	sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
### SETUP YOUR KEYS
    sudo apt install curl # if you haven't already installed curl
    curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -
### INSTALLATION
	sudo apt update
	sudo apt install ros-melodic-desktop-full
### ENVIRONMENT SETUP
	echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
### DEPENDENCIES
	sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential

Initilize rosdep:

	sudo apt install python-rosdep
	sudo rosdep init
	rosdep update
### PX4 DEPENDENCIES
	sudo apt-get install python-catkin-tools python-rosinstall-generator -y
	wstool init ~/catkin_ws/src
### MAVLINK
	rosinstall_generator --rosdistro melodic mavlink | tee /tmp/mavros.rosinstall
### MAVROS
	rosinstall_generator --upstream mavros | tee -a /tmp/mavros.rosinstall
### CREATE WORKSPACE AND DEPS
	cd ~/catkin_ws
	wstool merge -t src /tmp/mavros.rosinstall
	wstool update -t src -j4
	rosdep install --from-paths src --ignore-src -y
### INSTALL GEOGRAPHIC LIB DATASETS
	cd ~/catkin_ws
	sudo ./src/mavros/mavros/scripts/install_geographiclib_datasets.sh
### BUILD SOURCE
	cd ~/catkin_ws	
	catkin build
	
## 2) PX4 Environment Development

### DOWNLOAD PX4 SOURCE CODE
	git clone https://github.com/PX4/PX4-Autopilot.git --recursive

### RUN UBUNTU.SH
	bash ./PX4-Autopilot/Tools/setup/ubuntu.sh
	#Restart computer after it is done

### BUILD ROS/GAZEBO: Gets Gazebo9
	wget https://raw.githubusercontent.com/PX4/Devguide/master/build_scripts/ubuntu_sim_ros_melodic.sh
	bash ubuntu_sim_ros_melodic.sh

#### Download QGroundControl from:
	https://docs.qgroundcontrol.com/master/en/releases/daily_builds.html

#### Build jMAVSim and Gazebo
	cd ~/PX4-Autopilot
	make px4_sitl jmavsim
	#May need to open QGroundControl for it to work
	make px4_sitl gazebo

#### Create px4 package
	cd ~/PX4-Autopilot
	DONT_RUN=1 make px4_sitl_default gazebo
	source Tools/setup_gazebo.bash $(pwd) $(pwd)/build/px4_sitl_default
	export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)
	export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)/Tools/sitl_gazebo
	roslaunch px4 posix_sitl.launch

## 3) oscillation_ctrl Dependencies
### INSTALL XTERM
	sudo apt-get update -y
	sudo apt-get install -y xterm

### INSTALL MAVROS_CONTROLLERS
	cd ~/catkin_ws/src
	#clone repo:
	git clone https://github.com/Jaeyoung-Lim/mavros_controllers
	#Download dependencies: 
	cd ~/catkin_ws
	wstool merge -t src src/mavros_controllers/dependencies.rosinstall
	wstool update -t src -j4
	rosdep install --from-paths src --ignore-src -y --rosdistro $ROS_DISTRO
	catkin build
	source ~/catkin_ws/devel/setup.bash
	#####Troubleshooting: https://github.com/Jaeyoung-Lim/mavros_controllers
### TOOLS/SITL_GAZEBO
	copy (or add) files in 'oscillation_ctrl/models' and 'oscillation_ctrl/worlds' to 'PX4-Autopilot/Tools/sitl_gazebo/models' and 'PX4-Autopilot/Tools/sitl_gazebo/worlds' respectively
### ROMFS/PX4FMU_COMMON
	copy (or add) files in 'oscillation_ctrl/airframes' to 'PX4-Autopilot/ROMFS/px4fmu_common/init.d-posix/airframes'
	add file name to 'CmakeLists.txt' in same 'airframe' folder (with number)
	add airframe name in '~/PX4-Autopilot/platforms/posix/cmake/sitl_target.cmake' (no number!)
### LAUNCH FILES
	copy (or add) files from px4_launch directory to '~/PX4-Autopilot/launch'
### MAVROS
- in px4.launch, replace:
'''
arg name="fcu_url" default="/dev/ttyACM0:57600" 
arg name="gcs_url" default="udp-b://127.0.0.1:14555@14550"
'''
- with:

	arg name="fcu_url" default="udp://:14551@192.168.1.91:14556"
	arg name="gcs_url" default="udp-b://127.0.0.1:14555@14550" 

#### CHANGE DEVEL/SETUP.BASH
In catkin_ws (or any working directory) add to devel/setup.bash:
		CURRENT_DIR=$(pwd)
		cd ~/PX4-Autopilot

		source Tools/setup_gazebo.bash $(pwd) $(pwd)/build/px4_sitl_default
		export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)
		export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)/Tools/sitl_gazebo

		cd $CURRENT_DIR

## JINJA TETHER FILE
- spiri_with_tether.sdf.jinja can be altered to create desired tether model
- changes nede to be made in px4 directory and will only take effect and 
"make px4_sitl gazebo"
	- can do DONT_RUN=1 make px4_sitl gazebo to avoid starting px4 shell and gazebo
- First two elements can be changed to tweak tether parameters
	- number_elements: number of segments tether will be composed of
	- tl: segment length (should be no shorter than 0.3 meters)