As some may have noticed, I’ve created a Steering Turn Rate Control Tuning video and added it to our wiki.
It is just a starting point, focusing only on Ackerman rovers and shows how to view the desired and achieved turn rate in real-time and instructs people to increase the ATC_STR_RAT_FF until the achieved matches the desired. Still, this really is the most important thing to get right when tuning the steering controller so hopefully it will help new users in particular.
As a pre-requisite for testing in Acro it also quickly covers setting the ACRO_TURN_RATE parameter so that the driver’s steering stick requests an achievable turn rate while in ACRO mode.
I’ll be doing a more in-depth video for the skid-steering vehicles soon-ish and then after that boats.
Great video! The video in this page is your throttle tuning one, not the steering. The one in the wiki is correct.
Based on trying to work through the code in Excel, I think ATC_STR_RAT_FF should be the turning radius (or at least close to it. You ended up at 1.2? What was the actual turning radius?
The turning radius of the vehicle is quite tight, it could be close to 1.2m. I guess it’s possible that what you’re saying is correct, I haven’t worked through the numbers. That would be nice if it worked out that way!
I cannot understate the importance of videos like this. I figure the more the better so for those of you out there in rover land who have video’d any of the tuning steps, please UL your video! Maybe there could be a folder on this forum that is dedicated to video’d tips… or is there one already
We can add an endless number of tuning videos to the tuning wiki pages. Alternatively we could create a play list on the ardupilot YouTube site. Anyway, if more people submit videos we can organise them in one (or both) of these ways…
I used this video to tune my skid-steering farm bot. The description and parameters made sense when applied to this style of robot. I’m much happier with the steering response now. It’s pretty snappy.
I looked at the throttle one too. It was also applicable to the skid-steering design, but I’d already got that close to where it should be by the instructions in the wiki.
I’d love to see a video on navigation tuning. I went way outside the recommended range, in a counterintuitive way, but it’s really good now. If I see an example on video it will help to know if my expectations are reasonable, and my method of tuning is sound.
At the end of the day the results are the important thing. However, I thought that tuning was really hard, and I was disappointed by my first attempts. They worked, but I felt I was doing it wrong and it would be too hard do it better. Not so- the video clarified it immensely.
If you are making a video focusing on skid-steer robots I’d like to see it, but I’m not sure they need much that is different to what you showed here. Anyway, thank you.
yes, the skid-steering tuning method is quite close to this one. The next tuning video I’m planning is for a skid-steering boat. After that will probably be a navigation tuning video… I must admit that I don’t know the method yet (for tuning navigation) but some of the other devs will assist I’m sure.
