You are correct. If you use RSC Setpoint mode then you do NOT have to set up the throttle curve.
To my knowledge the tail control method does not change between acro and stabilize. It is still rate command, heading hold. I would have to see your data or you could look at the signal PIDY.I to see if the integrator is saturating. That could cause the flight controller to lose heading hold. In that case you want to in crease the tail rotor pitch mechanically so that the tail pitch at trim (neutral) rudder position is the tail rotor pitch required for hover. That will help keep the integrator from saturating.
Adjusting tail rotor pitch will not affect the drift problem.
The AHRS trim should be set so that the roll reads 0 deg with the main rotor shaft aligned perfectly vertical. The same is true for pitch. If the AHRS trim are set that way then you will just adjust the ATC_HOVR_ROL_TRM parameter until it hover with no drift on a calm wind day. This is not an exact science. It will still drift a little regardless but you just want to remove any consistent drift in one direction.
Hereās a vid (sorry about the quality) - itās moderate wind, and you can see as i hover and center the sticks, it starts drifting left. Iām at 600 deg ATC_HOVR_ROLL_TRM at the moment - can i go any further? or itās something else
I havenāt tried the AHRS Trimās so far.
Do you think itās not enough head speed at hover?
Ok bill, will do that tomo, I have never done it before. I see the log dates are all 1980, probable as i have not added a GPS yet? Iām unable to figure which one was the latest log. I probably clear all of them and do a fresh flight and download the log.
Will come back when i have done that.
I just got a Mateksys F765 Wing to replace the revo board on my other 450 - is there a set way to train the ESC for high/low with AC Heli?
I just cannot get it to initialize, i dont get the normal tones when i power up. I have ensured the servo 8 is HeliRSC and the Min and Mid are close to each other and are same as throttle min on the RC In.
On my PRO, with a different esc i somehow managed to initialize it, but just unable to do the same on this esc. Everything else is fine, ARMING, Servo8 output etc. But no esc init, so no motor drive.
Hi Satish, you sent the tlog which is what mission planner records. I would really like the bin file which you download from the flight controller. You plug a USB cable from your computer to the flight controller. Then connect to the flight controller in mission planner. From the flight data tab, there is a Dataflash tab in the lower left panel. You use the upper left button which is download logs and then choose the last log in the list. You will find the logs in the documents folder under mission planner/logs/helicopter/1/
Here is the problem. Your roll attitude is not following your desired roll attitude. This is caused by ATC_RAT_RLL_ILMI being zero. Set both ATC_RAT_PIT_ILMI and ATC_RAT_RLL_ILMI to 0.08. That will allow the controller to hold attitude for you.
Ok Looking at your parameters further, have you even attempted to tune this heli. The PID parameters are all default values. So in addition to setting the ILMI parameters, you need to tune this heli properly.
Thanks bill for your time - I will set them and try.
No, i have not done any kind of PID tuning as yet. I guess that will be the next challenge for me. I look forward to it.
bad weather all weekend, just had a window in between, i made changes you mentioned and tested, the drifting had reduced quite a bit, still had some drift, had to change the ATC_HOVR_ROLL_TRM from 300 to 400 (i had reset it back to default), and tested again, and it felt much better, i guess i can go 450 on this setting on my next test flight, the ATC_HOVR_ROLL_TRM seems to be having an effect only now after your suggested setting with ATC_RAT_PIT_ILMI and ATC_RAT_RLL_ILMI to 0.08. I have attached the bin file for your reference and suggestions.
Please suggest where I start the tuning process.
as of now there is no roll/pitch oscillations, stick response feels ok.
tail is what i feel is a bit loose in holding heading. Doesnāt feel solid.
Hello Bill,
(please let me know if i shuld start new thread for this)
I have a similar setup i mentioned but with 765-wing, AC 4, and 450 flybar heli.
I have followed the tuning first steps as per document ATC_RAT_PIT_VFF and ATC_RAT_RLL_VFF at 0.15. I was getting roll-oscillations just at lift off, so i reduced the ATC_ANG_RLL_P from default 4.5 to 3, and i now see roll-oscillations just after lift-off.
Iām not sure if ATC_RAT_PIT_ILMI and ATC_RAT_RLL_ILMI = 0 is coming into play here as well, or itās simply vibrations.
I have the bin log attached, kindly suggest/guide me.
Hi Satish,
The first heli is looking good as far as the actual attitude following the desired. It is tough to tell with the log bitmask setting but it appears that you do have some vibrations that you may want to address first. I would suggest setting the LOG_BITMASK to 131071 and conduct a flight. You will probably see oscillations in the RATE.R and RATE.P signals at the same freq as your rotor speed. I would first suggest that you ensure your blades are properly tracked and balanced. Then you can use the notch filter to get rid of more of the noise.
Then you can start tuning. Please read the TradHeli tuning guide on the wiki. If you need a link let me know. I would prefer that you read the wiki and try it yourself and then you can come to me with questions. I want you to learn how to do this yourself.
As for your other heli, there are some significant vibrations. I also suggest change the log_bitmask to 131071 on this heli and then addressing the vibration issues before trying to tune it.
Thanks Bill for taking time - iām learning every time i interact with you. I will try to isolate the vibrations and re-test with the LOG setting you mentioned. Could you kindly help me with using the log-analysis in MP, how do i plot the Roll and DesRoll against time for example? I couldnāt figure after loading the binary file. Hereās what I see. I;m not sure how to select the datasets from the table below to plot the graph
The fc is right now over the the antirotation bracket just over the tail-boom holder box with soft foam tape - you have any suggestions for a better place/method on the 450 pro?
See the panel on the right side of the graph. Those are all of the messages(data) that are saved to the Dataflash log. ATT is the attitude controller data, RATE is the rate controller data. So if you expand the message by hitting the ā+ā beside it, it will show all of the data available to plot for that message. Click the check box beside the data you want to view on the graph.
That is odd. I am pretty sure I have looked at you logs and didnāt have any issues with time. You may want to upgrade your version of MP. Looks like you are using 1.3.63 and we are not up to 1.3.72 l think.
HELI-2 (450, FlyBar) - had some time to make some adjustments to isolate vibes, and a test flight, felt a lot better, very little roll-oscillations, just occational tail jerks, otherwise itās flyable for now. Above i have attached the log. I will try to get rid of the little vibes, but have to wait another week for some parts to come.
There was a slight left-roll drifting on this as well (just like my HELI-1 450 PRO FBL) - can i set the ATC_RAT_PIT_ILMI and ATC_RAT_RLL_ILMI to 0.08 on this as well?
Let me know your insights from the log, what i should be looking at next in the log and what to make of it.
No changes, just tried to remount the FC away from vibrations as far as i could/allowed with parts I currently have. Flies well, just a bit loose tail hold.
Let me know what you think of the vibrations - i did set the bitmask as you mentined.
