Видео

No it works for rovers too, It's not easy to find good info on how to set it up though. I know I went through a nightmare a while back and gave up after I got the results in this video with a hacked together steering controller (depreciated at this point). Eventually, a newer firmware version was released that finally shipped with the missing rover attitude / position controllers as standard. I'm not sure why you wouldn't see it as an option though...? \_(-_-)_/ What version of QGroundControl are you using? What version of the PX4 firmware are you running? I don't know if it makes a difference, but I use the current development branch.

I understand it must have been an intense nightmare. Do you know which is the latest or best version of PX4 which supports rover?

My apologies, I didn't see the remainder of your reply. I installed the latest version of both QGC and PX4 and now I see the rover "air frame" option! Thanks for the hint. Cant wait to get to building/tuning! one last question, I see the 3 options for rover vehicle types are "generic ground vehicle, axial rc car, and the stampede rc car" ; is there a skid steer or tank steer vehicle option or only ackerman style vehicles. ?

What you need is a motor controller that has the ability to take the ackerman-style ( 2 Channel RC PWM | Steering / Throttle ) signals from the pixhawk and control a differential / skid drive motor pair. I'll list a good one below that's good for most motors: www.robotshop.com/en/sabertooth-dual-2x32a-6v-24v-regenerative-motor-driver.html The control mode I'm talking about is detailed on page 20 in the data sheet: www.robotshop.com/media/files/pdf/rb-dim-47-datasheet.pdf A video demo of this using a wheel chair and raw rc receivers and this motor controller (no pixhawk involved): ruclips.net/video/hS_yKXXlUsc/видео.html ( works with wheel chair motors )

That's exactly what I was looking into you read my mind. Thanks again for all the help I'll keep you posted as the project unfolds.

So first off, the "iris.sdf" file gets re-generated every time you run make posix_sitl_gazebo. (be careful modifying it in place, might get overwritten). I think it's made from a ".urdf" file. I don't know anything about urdf, so I just first copy the iris model folder from wherever it gets built to my ROS workspace ( I use "ROS_workspace/models" for my model directory, but anywhere works as long as it's set in your ".bashrc" file | GAZEBO_MODEL_PATH ). Then I modify the file to add the camera. I added this INSIDE of the <base_link> tag towards the bottom ): <collision name='base_link_lump::camera_link_collision_1'> <pose frame=''>0.12 0 -0.01 0 0.7 0</pose> <geometry> <box> <size>0.05 0.05 0.05</size> </box> </geometry> <surface> <contact> <ode/> </contact> <friction> <ode> <mu>0.2</mu> <mu2>0.2</mu2> </ode> </friction> <bounce/> </surface> <max_contacts>10</max_contacts> </collision> <visual name='base_link_lump::camera_link_visual_1'> <pose frame=''>0.12 0 -0.01 0 0.7 0</pose> <geometry> <box> <size>0.05 0.05 0.05</size> </box> </geometry> <material> <script> <name>Gazebo/Red</name> <uri>file://media/materials/scripts/gazebo.material</uri> </script> </material> </visual> <sensor name='camera1' type='camera'> <update_rate>20</update_rate> <camera name='head'> <horizontal_fov>1.39626</horizontal_fov> <image> <width>320</width> <height>240</height> <format>R8G8B8</format> </image> <clip> <near>0.02</near> <far>300</far> </clip> <noise> <type>gaussian</type> <mean>0</mean> <stddev>0.007</stddev> </noise> </camera> <plugin name='camera_controller' filename='libgazebo_ros_camera.so'> <alwaysOn>true</alwaysOn> <updateRate>20</updateRate> <robotnamespace>iris</robotnamespace> <cameraName>mavlink/</cameraName> <!-- Video feed will be pushished as: ... --> <imageTopicName>image_raw</imageTopicName> <cameraInfoTopicName>cam_info</cameraInfoTopicName> <frameName>camera_link</frameName> <hackBaseline>0.07</hackBaseline> <distortionK1>0.0</distortionK1> <distortionK2>0.0</distortionK2> <distortionK3>0.0</distortionK3> <distortionT1>0.0</distortionT1> <distortionT2>0.0</distortionT2> </plugin> <pose frame=''>0.12 0 -0.01 0 0.7 0</pose> </sensor> This is from an old workspace so I hope it still works for you. Let me know how it goes.

Thank you very much for your help!!

what you need is the 'mavros' ROS package (I'm on indigo): sudo apt-get install ros-indigo-mavros ros-indigo-mavros-extras It provides a way for the virtual px4 to connect to it, and from there, allows a 'gcs_bridge' udp address to be forwarded to QGroundControl. Sorry it took me so long. Here's my mavros launch script: <!-- ___________________________ MAVROS ________________________ --> <!-- this is the px4 SITL address, QGroundControl default I think --> <arg name="fcu_url" default="udp://:14550@127.0.0.1:14557" /> <!-- mavros forwards a multiplexed MavLink stream to this udp port --> <arg name="gcs_url" default="udp://@127.0.0.1:12600" /> <!-- gotta start px4 and mavros first; otherwise, QGroundControl will bind to the default port. I disabled the default connection. note: you'll have to create a new connection in QGroundControl's general settings and provide the correct udp port to mavros --> <arg name="tgt_system" default="1" /> <arg name="tgt_component" default="50" /> <arg name="log_output" default="screen" /> <include file="$(find mavros)/launch/node.launch"> <arg name="pluginlists_yaml" value="$(find mavros)/launch/px4_pluginlists.yaml" /> <arg name="config_yaml" value="launch/px4_config.yaml" /> <arg name="fcu_url" value="$(arg fcu_url)" /> <arg name="gcs_url" value="$(arg gcs_url)" /> <arg name="tgt_system" value="$(arg tgt_system)" /> <arg name="tgt_component" value="$(arg tgt_component)" /> </include> In short, gazebo rotors / imu plugins connect to the PX4 SITL as default. The PX4 SITL connects to the mavros node as if it were QGroundControl. Then, mavros exposes a multiplexed MavLink port to QGroundControl. Now mavros can send commands to the PX4 or QGroundControl can send commands (through mavros) to the PX4 and they all can communicate properly. Yeah it's kind of a frustrating set-up at times.

I want to know the same thing

Yeah it took me many many hours to understand how to get a ROS-Topic enabled camera in the simulation, theres very little documentation on it. I host the simulation on a live gzWeb Server: uah-iarc-dev.org:8080 The bulk of the work is in the gazebo 'model.sdf' files. Gotta have gazebo 6, ros-indigo-gazebo-pkgs, and either launch gazebo via a roslaunch script or manually run it with the ros server plugin: gazebo --server-plugin /opt/ros/indigo/lib/libgazebo_ros_api_plugin.so [Your_File.world] be sure to set all the environment variables for gazebo, namely the plugin path variable: export GAZEBO_PLUGIN_PATH=${GAZEBO_PLUGIN_PATH}:/opt/ros/indigo/lib Total pain in the ass, trial and error got it to work for me. ################ Here's some important bits of the .sdf I file used ############### ###### Camera Deffinition / this is the .sdf file telling gazebo to add a camera to some ###### pre-defined position on the robot, a.k.a. , "the camera link" ###### this also defines the ros topic name / image format and various other camera ###### parameters. <sensor name='camera1' type='camera'> <update_rate>20</update_rate> <camera name='head'> <horizontal_fov>1.39626</horizontal_fov> <image> <width>752</width> <height>480</height> <format>R8G8B8</format> </image> <clip> <near>0.02</near> <far>300</far> </clip> <noise> <type>gaussian</type> <mean>0</mean> <stddev>0.007</stddev> </noise> </camera> ### here is where most of the ros stuff gets defined. Be sure that GAZEBO_PLUGIN_DIRECTORY ### (bash environment variable) includes the ros-gazebo-pkgs directory. <plugin name='camera_controller' filename='libgazebo_ros_camera.so'> <alwaysOn>true</alwaysOn> <updateRate>20</updateRate> <robotnamespace>iarc-robot</robotnamespace> <cameraName>sensor/cam_1</cameraName> <imageTopicName>image_raw</imageTopicName> <cameraInfoTopicName>cam_1_info</cameraInfoTopicName> ### this next part is important, make sure to have defined this link ### may need to read up on .sdf spec and how scripted links work <frameName>camera_link</frameName> <hackBaseline>0.07</hackBaseline> <distortionK1>0.0</distortionK1> <distortionK2>0.0</distortionK2> <distortionK3>0.0</distortionK3> <distortionT1>0.0</distortionT1> <distortionT2>0.0</distortionT2> </plugin> <pose frame=''>0.12 0 -0.01 0 0.7 0</pose> </sensor> just send me a PM if you need any more help or if you got a specific error message that keeps ruining your day.

Thank you! I let you know about the final result! :)

Glad to help, I'll be looking forward to it then.

+macfly1202 I did it for a university project. I wound up spending more money and time on it than I had planned. :-/ I just don't have the spare time or money to do much with it at this point.