Should I modify redtail ros packages or create new packages ?

[earcz]

Hi, To implement redtail project by adding new features, I am working on ROS for a while, but got stuck. I want that the drone flies along the x and y directions (like _altitude_gain:=2) for searching a specific object (i.e maze) after gaining specified altitude. If we split the tasks into 2

1) For movement along the x and y directions, how can I add the feature of flying along x and y directions? Which ros files of redtail should I modify? or Should I create new files?

2) For searching specific object (idk if YOLO detects maze or not), I need to use image processing. Is there any easy way to do this by using ROS? (i.e readily available ros packages)

Best.

[Alexey-Kamenev]

There are few things you may want to consider.

1. If you goal is to simply move laterally, then you can use the same approach we used in our px4_controller which is a waypoint navigation via MAVROS. To move the drone in x,y directions, px4_controller publishes waypoints using setpoint_position topic. Please refer to MAVROS wiki and px4_controller sources for more details.

2. If your goal is to perform complex navigation using data from multiple sensors then you should look at ROS navigation stack.

3. Our YOLO DNN was trained on PASCAL VOC dataset so it recognizes only simple classes from that dataset. If you want something else, you can either train a different DNN or use some other computer vision techniques (e.g. from OpenCV). ROS provides integration with OpenCV via vision_opencv package.

[earcz]

Thank you Alexey, you provided good points. One more thing. I am trying to change the location of the host computer for qgroundcontrol because when the GCS is opened, map shows Zurich, not my location. When I modified the redtail/ros/packages/px4_controller/launch/mavros_caffe_ctl.launch for fcu_url and gcs_url, nothing is changed. How to set my location instead of Zurich ?

[Alexey-Kamenev]

fcu_url parameter specifies the address of FCU (e.g. real Pixhawk or the simulator). gcs_url specifies the address of a machine where GCS (Ground Control Station, e.g. QGroundControl) is running. See this for more details. As for the map in QGC - since you don't have a GPS lock, it will use default map which is Zurich. You can probably change that to something else but I haven't tried that. Hopefully QGC documentation can provide more details.

[earcz]

Thank you for the information.

[earcz]

I needed to reopen the topic. You said that I don't have GPS lock. However, when I start the gazebo simulator with mavros and QGroundControl, there is written GPS lock: 3D Lock under the GPS status toolbar. Doesn't that mean that I have a GPS lock ?