Gazebo Simulation

Aruco Visual Markers for Gazebo Simulator

Forked from https://github.com/joselusl/aruco_gazebo

Installing Gazebo

Goto the Installing gazebo's README to install gazebo and other dependencies

Installing offboard node

To run offboard example given on px4 source

1. In a new terminal run roscore for starting master.

2. In a new terminal open ~/catkin_ws/src where our ros environment is installed

   Let's create a new package named offboard in that src and run it.

   *create a new package with dependencies using catkin_create_pkg offboard std_msgs rospy roscpp

   *This creates a new CMakeLists.txt, src folder and package.xml

   *Edit the CmakeLists.txt add this snippet at last add_executable(offb_node src/offb_node.cpp) target_link_libraries(offb_node ${catkin_LIBRARIES})

   *Inside the src folder create offb_node.cpp and copy paste the code from here

   *type the command in our workspace catkin_make to build our catkin package.

   *rosrun offboard offb_node to run our offboard package.

3. In new terminal goto ~/src/Firmware

   Launch the mavros by command roslaunch mavros px4.launch fcu_url:="udp://:14540@127.0.0.1:14557"

4. In a new terminal goto ~/src/Firmware

   Launch the gazebo simulator by command make posix_sitl_default gazebo

Now the offboard example is enabled u can see the quad takeoff in the simulator.

Installing iris camera

To install a simple camera facing downwards at bottom of IRIS quadrotor model in Gazebo and publish its frames on ROS(Kinetic).

This tutorial assumes your have cloned Firmware folder in ~/src/Firmware and have successfully all its dependencies.

• To install a camera in IRIS proceed as follows:-

1. Open iris_base.xacro present in ~/src/Firmware/Tools/sitl_gazebo/models/rotors_description/urdf/

2. Search in iris_base.xacro and add the following code just above it and save it.

   Add these lines

   <xacro:camera_macro namespace="${namespace}" parent_link="base_link" camera_suffix="red_iris" frame_rate="30.0" horizontal_fov="1.3962634" image_width="800" image_height="800" image_format="R8G8B8" min_distance="0.02" max_distance="300" noise_mean="0.0" noise_stddev="0.007" enable_visual="1" > </xacro:camera_macro> save it .

• To Run the gazebo simulation follow these

  1. Go to ~src/Firmware
     run the command no_sim=1 make posix_sitl_default gazebo as shown in What's Happening Behind the Scenes it will initialize the gazebo

  2. To open our iris Go to Firmware again in new Terminal run the command bash command "source Tools/setup_gazebo.bash $(pwd) $(pwd)/build/posix_sitl_default"

     Then run the command "roslaunch gazebo_ros empty_world.launch world_name:=$(pwd)/Tools/sitl_gazebo/worlds/iris.world" in the same terminal

Now we can see our iris with camera in gazebo simulator

Open New terminal to see published raw images Type "rostopic list" to see the list of topics where we can see '/iris/camera_red_iris/image_raw' So our camera is working and publishing our images to ros

You can also visualize it by typing rosrun rqt_image_view rqt_image_view

Then see the image of our camera in iris quad in /iris/camera_red_iris/image_raw.

Aruco detection in gazebo

First launch the simulator in here

Clone this repo to downloads

source to clone the repository

Now copy the aruco_7(not the aruco7_pad folder) folder to ~src/Firmware/Tools/sitl_gazebo/Models

Now replace the iris.world given in this repository file to ~src/Firmware/Tools/sitl_gazebo/Worlds

Now run roscore

Now rosrun offboard offb_node

goto ~src/Firmware

roslaunch mavros px4.launch fcu_url:="udp://:14540@192.168.1.36:14557"

In other terminal execute this code

In other one source Tools/setup_gazebo.bash $(pwd) $(pwd)/build/posix_sitl_default

roslaunch gazebo_ros empty_world.launch world_name:=$(pwd)/Tools/sitl_gazebo/worlds/iris.world

no_sim=1 make posix_sitl_default gazebo

Time to detect Aruco now

The calibration data which we got during calibrating the camera in gazebo ; Now create a .yaml file and insert that data into it . Backup the head_camera.yaml file of the usb_camera (@ ~/.ros/camera_info) and replace the newly created file with the name head_camera.yaml.

goto catkin_ws/src/aruco_ros/kinetic/devel/aruco_ros/launch/single.launch and change line 13 in it with this code.

<script> remap from="/image" to="/image_rect_color" </script>

and save it.

catkin_make and source devel/setup.sh

to increase the size of aruco goto home/src/Firmware/Tools/sitl_gazebo/Models/aruco_visual_marker_7 and edit the model.sdf file make the size 0.5

roslaunch usb_cam usb_cam-test.launch

rosrun image_proc image_proc image_raw:=/iris/camera_red_iris/image_raw camera_info:=/usb_cam/camera_info

roslaunch aruco_ros single.launch markerId:=7 markerSize:=0.5

rosrun rqt_image_view rqt_image_view and select stream .. /aruco.single/result

Now you can get the pose data from the topic aruco.single/pose

Hovering over the aruco

clone this offboard node to the src of catkin folder (this is modified one)

Now catkin_make and source it

follow the aruco detection in gazebo again .

now modify the iris.world and change the size of aruco in the models