Rover in GUIDE mode

As a side note, I wonder if someone could raise a PR with mavros to get the external position plugin removed from the blacklist (or added to the whitelist?)? The PR to add support to ardupilot should go into master tomorrow.

Ok, mavros is working ok now.

Does anyone knows a ROS package that takes google maps waypoint (lat lon) and current position and send commands (cmd_vel) to the rover to navigate? supposing that there is no obstacles between Rover and WP?

Thank!

the PR to add support for the external position mavlink messages has gone into master now. It will probably take a few hours for the autobuilder to complete building it and then the latest firmware can be loaded using the mission plannerā€™s install firmware screenā€™s magic Ctrl-Q feature. You should see the version name under the vehicle icons change to xxx-dev.

If anybody could give this a test that would be really great. Weā€™ve tested it in the simulator but not with ROS.

Modification on Mavros submitted !

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can you explain a little more this feature?
I think I could test it this week (Iā€™m planning some experiments on the stearn this weekend).

Thanks @khancyr.

I forgot to mention that this change has only been made to the EKF2 for now. EKF3 will come in the near future.

@Leonardo,
This makes it easier for external systems (like ROS) to send in external position estimates and have the EKF consume them. Good for non-GPS environments.

Hi Leonardo,

I currently use this to send commands to ardurover via mavros

rostopic pub -r 10 /mavros/setpoint_velocity/cmd_vel geometry_msgs/TwistStamped ā€˜{stamp: now, frame_id: fcu}ā€™ ā€˜[[0.5, 0, 0], [0, 0, 0.00001]]ā€™

The above command tells the rover to move straight

excellent, that is working right on my side too.

Now I have to go to ROS site to get some answers there.
I will keep informed about my progress.

Thank!

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Hi @khancyr and @rmackay9,
I am trying out a boat for a competition. I am familiar with ArduSub a bit by using BlueROV. I have been trying to learn a bit on Mavros and ROS in general and has followed tutorials on the ardupilot website.

The boat I am trying to Configure has the following specs:

  1. Pixhawk Controller running ArduRover with X-Frame Configuration(or ArduSub)
  2. 4 Thrusters from BlueRobotics
  3. GPS
  4. Realsense Camera (D435) to detect obstacles

I had previously tried motors using RC_Channel_override commands on ArduSub and I feel it should work on ArduRover as well. But after learning ROS, I have a few questions that I hope you should be able to answer. My questions can be foolish as I am starting out.

  1. In Guided Mode Navigation, can the boat resist water current and wind and reach a certain point? Is Stabilisation or position hold working in that mode?

  2. In the competition, I want to go to location based on Buoys, which I feel can be tagged by going around the circuit and noting the point of interest. If I do this, can the MAVROS setup give me the ability to navigate through waypoints?

  3. If I am using RC_channel_override and writing my own Stabilisation and Position hold algorithm, can I still use ROS features of Navigation because I am not using the command to send velocity.?

Hope to hear from you guys soon.

@naval_architect I am quite late to reply to this message but I can answer at least to point 3:
RC_channel_override can be used without being in GUIDED mode. Yes you can you use all the ROS navigation stack of course, if you write you own controler and then override RC channels with your own computed values.

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Hey Leonardo, howā€™s your project ā€œcooperative control between a UAV and an ASVā€?

It was delayed by pandemic. I was working on a new ASV model, making some simulation, doing some conference papers. I hope on the following month I could start some field testing.

@elgarbe

I also tried publishing velocity commands to /mavros/setpoint_velocity/cmd_vel in GUIDED mode but sometimes the thrusters are moving even if I donā€™t publish any commands or just give zero value for linear velocity.

Did you face any similar issues or can think of any solution?

Thanks

I donā€™t remember what topic Iā€™ve been using, but I donā€™t face that problem of thrusters spinning with set point equal to zero.
Maybe on an indoor test if the navigation part estimate a current velocity different than zero and your set point is zero then the motors could start.
What is tour setup and how do you perform your tests?

Best regards

@elgarbe
i am doing the bench tests outdoors to get a GPS signal and the boat is stationary.