I am opening this topic to serve as the go-to place for talking about the upcoming 2.9 software release for Trad Helis. I think this will be necessary as 2.9 will have SIGNIFICANT changes in the way that the helis fly, and also in the settings you will use.
Yesterday, I flew 4 packs of "2.9 - rc2" from the downloads section on my 450 heli. The file is located here:
I would be interested in having some other people try some test flying with this. I'll have to walk you through the setup, as it requires a bit of work to get a flying parameter setting using the rate controllers which are now active. You CANNOT fly using the old parameters for Stabilize PID. Don't even try it. Also, the Alt_Hold parameters will have significantly changed.
This is slightly complicated by the fact that we have some new Heli-specific Rate PID parameters called "Rate_Pitch_FF", also for Roll and Yaw. Unfortunately these are only accessible in MP from the Advanced Parameters List. Hopefully I can get that fixed. What I'd like to do is for TradHeli, in MP, remove the Rate_Pitch_D, in the Config PID screen, and replace it with Rate_Pitch_FF. This is because I have found the D-term to be completely unusable anyway. The FF is feed-forward. This was what I found was the key to getting the heli to be able to fly in rate mode. Basically, it is like P-term, but has no error correction. It's sort of like this:
P-output = P-term x (Rate Input - Current Rate)
FF-output = FF-term x Rate Input
then you also have the I-term output. So the total servo command is:
Servo-output = P-output + I-output + FF-output
I have also implemented the FF on the yaw controller, and found that it actually helps to stop the slight "tail wag" that we always had.
There are also some new settings for the collective. These are Stab_Col_Min and Stab_Col_Max. What these are for is sort of like Idle-up pitch curves. You can now set up your swash plate with full negative pitch, maybe a range of -10° to +10°, or +/-12°, but when flying in Stabilize mode, you can set Stab_Col_Min to reduce the amount of negative pitch available to something like -3° or whatever you prefer. This gives a nice soft feel. However, in Acro mode, you will get the full range, and also the auto-pilot modes get the full range. For example, I set my Col_Min and Col_Max to give me +/-10°, and then I set Stab_Col_Min to 40, which is 40%, and this changes the negative pitch to only -2° in Stab mode.
The only thing to know here is that when you change modes between Acro and Stab, the swash-plate will jump up and down, so you have to be ready for it. It's no different than using Idle-up in your Tx.
My test flights yesterday went quite well. The Alt_Hold now works beautifully, and I actually prefer landing in Alt_Hold rather than Stabilize! I also did a few flips with it in Acro mode (very ugly, I'm not good at this) using full negative collective when upsidedown, and it worked well. It didn't seem to get confused. Finally, I tried going into Acro, rolling it over upside-down or sideways, then back to Stabilize, and it flipped right way up which is good.
The only problem I have seen so far is that when flying in Alt_Hold, if you push the cyclic full forward and get up a high speed, the altitude starts to oscillate badly. I suspect this is a classic "phugoid", or pitch/throttle oscillation. We'll have to work on this. However it seems to fly well up to about 1/2 Vmax.
I'll try to post my Parameter file here tonight, but I caution that the settings will be HIGHLY dependent on your servo speed, as well as many other setup differences.
Did you come up with a way to kill the motor with auto land besides going through the rc transmitter?
What do you mean exactly?
Currently, it follows the same procedure as the multi rotors. After auto landing, if you leave the throttle (collective) stick up, then it will just sit on the ground idling indefinitely.
When it is on the ground, if you drop the throttle stick to the bottom, it will disarm, which will shut off the motor on the heli.
So, you can use that to accomplish whatever you like. You can run the auto mission with the throttle down, and it will shut off as soon as you land. Or you can leave it up, so that you can control it manually.
And of course, hitting the Thr Hold switch (Ch8) at any time in the auto flight, it will shut down the motor, but will keep trying to fly... so it would probably stop the blades mid-air, with resulting carnage. So if you plan to fly auto missions outside of radio range, you need to be sure to set Ch8 high on your Rx failsafe setting.
This is awesome work. I am in the process of taking my FB T-Rex 450SEV2 to flybarless and adding the APM2.5. I have a Spektrum DX8, but need to get an 8 channel receiver.
I have read this thread through from the beginning. There have been a lot of "add this configuration" "change this configuration" discussions. There is so much info it is a bit confusing. I am not a programmer but I can muddle my way through some programming languages. This is a first for me on Arduino. so, now to the questions.
I have, I think, the Arduino IDC installed. Downloaded the libraries for ArduCopter-2.9.1b-final and ArduCopter-3.0-rc1
I don't have the APM2.5 in hand yet so i'm not sure how far I can get with out it?
I was going to go back through the discussions and collect all the configuration tweeks in the discussions but wonder of that has already been done?
Anyway Thanks, I am sure there will be lots of questions once all the hardware is in in place.
Hey guys, sorry for all the confusion, but I think there's really no need for you guys to go through all those steps and configuration changes. That was mostly during the early days when this setup wasn't mature anymore. You should not need to worry about compiling with Arduino IDE, nor worrying about Config files or any of that.
You simply install the APM, plug the USB cable in, and load it with 2.9.1 directly from Mission Planner. Then you just need to tune your PIDs. Pretty simple stuff.
Jeff, sorry, I don't know anything about Optical Flow setup.
Sweet, the APM should be here in a few days