I am trying to use Erle Rover in SITL and I got to know that ros_erle_followline works on OverrideRCIn messages and that is getting initiated only after having an entry-point through ArduPilot and many other packages (including plugins).
As I am trying to use it along with Copter, there has been a lot of issues; To avoid that, I am thinking about writing a direct-plugin/code which twists the joints through Joint-controller directly (either in C++ or in Python). (Another minor reason: I also realised that many people who do not use Ardupilot/FCU on Rovers can use your beautiful model directly)
As a result, I am thinking about spawning the Rover and issuing leftBottomWheelVelocity(v1), rightBottomWheelVelocity(v2), steeringPosition(x) functions in C++/Python. Regarding that, I found two approaches:
Using URDF joint names and mapping to C++ functions etc and writing from scratch (takes time).
Writing a package (if simple enough) to be used in Python just like baxter_interface so that the Rover can still follow line using image processing which is then converted to steering yaw angle and published.
While I have been able to see /rc/override output in terminal, I don't know how this can be modified without ArduPilot. (I would like to eliminate all dependent softwares if possible; MAVROS is fine if there is no other option as it is working for two instances independently)
Can you please let me know how I can finish this task? Or is it possible by you to create direct interface plugin and publish it on wiki? Mainly, can you please let me know if there is a possibility to control Rover easily without starting Ardupilot through sim_vehicle? Thank you so much for your time and consideration.
I consider this a fantastic opportunity to specifically thank the team for three things (as your time is very precious; Otherwise, my genuine gratitude and deserved appreciation to Erle team can extend to another message!):
For creating a simulator consisting of FCU unit and taking pains in making about 16 modules and packages inter-operable. (I am struggling with 5 and I just don't know how you have done it)
For speedy-resolution of previous problem in about 5 days; MAVproxy 1.5.2; that one was extraordinary (I'm sure I wouldn't have figured even the problem out that quickly)
For helping robotics community and writing not one-of-the-best but, the best documentation on SITL.
(Note: You are humbly requested to ignore this message/let me know if this requires significant engineering time)