Hello,
Thank you for the positive response, despite my rambling. (I apologize for this).
So to be as specific as I can be; I am trying to utilize the twist/pose controllers to manage low-level control - keeping the unit stable and moving it slowly from point to point - without having to set up a lifetimes worth of code. I need this first, and if everything works, (as I always expect but never experience), the next step is…more fancy.
Position is already handled by the established system, but as mentioned, it lacks the ability to handle a quad/jhexa-copter. This is the reason why I stated that I “don’t care if the autopilot knows where it is” - I have to tell it where it’s supposed to go nonetheless. At this time the tuning and understanding of PX4’s own filtration/fusion is beyond my capacity.*
I’ve done some small changes to the offboard example, and I’m now able to arm, change to offboard, send persistent setpoints - and I found another of my problems with getting some action: my frsky was not set up correctly. (It still ain’t, but I had another one which seemed to be. ) I’ve moved to a more “expendable” set-up, but I actually found the pixracer more cooperative than the pixhawk2; is this only because I now have RC-control? (I realized that was a stupid question as I wrote it).
Specifics:
- Main issue (as far as I understand atm): Lack of position for the autopilot.
Solution#1: Vicon_bridge as pr developer guide. This package no longer have the referenced launch-file (actually it was a .sh file?). Anyways, I don’t think it’s a good siolution to my case.
Solution#2: Publish NavSatFix with 7 (maybe 8?) decimals will yield higher accuracy than “naked” GPS (ofc dep on fix# etc), is this as simple as that, or do I have to do it in synergy with the editing of mavros’ configurations?
Solution#3: Publish position as a ROS transform? Am I understanding the option correctly? This would be the by
far best alternative for me.
1.2) To calculate from local Cartesian coordinates to GPS and forward it to mavros is a little extra work, no way of just using local coordinates given that home position is set?
- Is it my responsibility to provide accurate and updated position if I want the system to react to i.e drift or gusts of wind etc? If I’m publishing setpoints while the craft is at x0,y0,z0, while aaa… Yeah it must be, I guess.
I will do as you suggest after I’ve had a little sleep, hehe, get back to you then.
Btw; regarding documentation: I was using deprecated mavros until these last few days. Only when I randomly tried the install-script provided I got the soure-installed one with the correction utilities. This should be stated explicitly, binaries for kinetic is no good. (The scripts work excellent btw, thanks! )
The offboard example is also deprecated, just very small changes to the semantics and it’s good, but still not intuitive for those who are likely to use it as their offboard code.
Aaand, last ting, why not add a subscriber to pose, listening to a custom topic for new pose-messages (in offb_example)? If the pose is made global it can just be changed in the callback, removes the concern of both having to publish fast enough and being able to actually publish at your own pace (while not messing with the arming/offb checks). However I could be missing something crucial, as mentioned I really don’t have much clue.
Thank you!