Servers by jDrones

ROS driven ASV questions

(Leonardo) #1

Hi, I’m working on drive my ASV (differential drive catmaran, pixhawk, ardurover, raspberry pi) with ROS.
I want to confirm that /mavros/global_position/local is the current X-Y position, in ECEF coordinate and with origin in the home position. I mean, using this topic I can know the ASV position relative to the home position.
I want to confirm that using /mavros/setpoint_velocity(_position, I don’t remember wich one is correct)/cmd_vel I can gives velocity commands to the boat.
and finally I would like to confirm tha GUIDED mode is the one used to drive the boat with mavros and that I need to publish to cmd_vel topic at some rate before passing to GUIDED mode.

Thank!

(rmackay9) #2

@elgarbe, I can’t remember exactly which ROS topics should be used but I think the setup is correctly described on the wiki here. Guided mode is certainly the mode to use.

(Leonardo) #3

Thank @rmackay9.
What would it be the job needed to connect ardupilot in SITL with a boat in gazebo? I’m using some boats simulators, under gazebo, with ROS integration and it could be very interesting to have it working with ardupilot stack

(Kg Fairbarn) #4

I haven’t worked on the Arduboat in a year so I have a hard time recalling the issues we had. I initially setup a companion computer running ROS and had issues with ArduRover when frame_class=2 (arduboat) but had no issues using rover frame class. I’ll be working on a new ArduBoat running ROS in the next month so let me know how it goes. Probably a ROS node issue not recognizing ArduBoat frame class.

(Roland Arsenault) #5

I helped KG with some of the software to adapt our ROS-based framework. Looking back, the ROS node I wrote is the following: https://github.com/rolker/echo_helm

Looking at the code in https://github.com/rolker/echo_helm/blob/master/src/echo_helm_node.cpp
I see that I subscribe to the following mavros topics:

/mavros/global_position/raw/fix
/mavros/global_position/raw/gps_vel
/mavros/global_position/compass_hdg

and use the following services:

mavros/cmd/arming
mavros/set_mode
mavros/setpoint_velocity/mav_frame

I do remember some trial and error to figure out the right topics and services to use. I hope this helps!

(Leonardo) #6

I will start ground tests on a couple of weeks and water test on a couple of month (3ºC is to cold to get wet :slight_smile: )
So, I let you know how it goes.

I’m interested on echo sounder, is there some cheap sensor with just serial output? I don’t need a screen, just some depth message from serial output…