iNav for KakuteF4V2 based Tricopters

[billyd]

Angle mode still might be valuable to tune, because doesn’t INAV use that in automatic flight modes such as RTH and waypoints?

Ironically I had great position/altitude hold with the .7 but it’s not as good in the .5 hex. While everything else about .5 is much better in terms of tuning. I may have an issue with my compass and other calibrations though so it’s very likely just my aircraft’s problem and nothing to do with the change in firmware.

But the .5 hex for me was much easier to get tuned in INAV (no triflight yet, this weekend if weather is good). Again this could be due to issues with my possibly defective servo which then died, and going to the impossible tilt. So new servo new mechanics and the tail is much much better. However pitch and roll are behaving much better too, so I’m not sure it was my bad tail that gave me all the issues. I’m afraid I am not much help lol. I am anxious to hear how you do with .5 and tuning INAV. See if you find it easier as well.

[yumemi5k]

I got triflight 0.5 on iNav 2.3 working. First hover test went well and RPM telemetry worked. However, during initial configuration & bench tailtune process, gyro hardware LPF and yaw_jump_prevention parameters somehow became corrupted, only allowing me to arm and fly after fixing these through CLI. I’ll do a thorough diff audit before any serious fly testing as I am now unsure if more parameters have been corrupted in a more subtle way.

[billyd]

I finished tuning my tricopter in INAV and was very happy with it so tonight I enabled triflight.

Everything went very smoothly. After the airborne tailtune was successful I noticed the tail was little soft. So I started increase the P for yaw. I now have it set to 180! And it flies amazing. No hunting anywhere.

This is the first time since I bought the LR that I am confident in its flying and tune.

I may have stumbled across the magic bullet for this tail. 22HV servo (instead of the 210) driven at 6v (to avoid too high a speed which can cause trouble with triflight at least in older versions) and modded with the 4th wire for triflight. And then my version of the impossible tilt with bearings. The tail is amazing.

Here’s my tailtune results:

set tri_dynamic_yaw_minthrottle = 100
set tri_dynamic_yaw_maxthrottle = 100
set tri_dynamic_yaw_hoverthrottle = 1405
set tri_motor_acc_yaw_correction = 6
set tri_motor_acceleration = 18
set tri_tail_motor_index = 2
set tri_servo_angle_at_max = 400
set tri_servo_feedback = RSSI
set tri_servo_max_adc = 2751
set tri_servo_mid_adc = 1918
set tri_servo_min_adc = 1100
set tri_tail_motor_thrustfactor = 112
set tri_tail_servo_speed = 634

Are the first two lines the dynamic yaw gains? Mine defaulted to 100, which was coincidentally my INAV P for yaw. Not sure if that’s why. At any rate I left those alone and just cranked the P for yaw to 180. It still wasn’t hunting on punches. But it’s very locked in so I’ll leave it there.

Not sure what I’m supposed to do with those yaw gains. Perhaps I should put the P back to 100 and adjust those instead? Let me know.

Great work jihlein, .5 triflight on INAV is fantastic.

[jihlein]

Nope, leave the yaw P as it is. The whole concept here is to get the best tail behavior at hover. Then the dynamic yaw gains can be used, if needed, to tune the tail further on punch outs or throttle cuts. That’s the whole point of storing the hover throttle setting, so dynamic yaw knows where to apply the max gain and the min gain. They default to 100 (which is 1 scaled at 100), so at this setting the yaw P gain is applied with no scaling across the entire throttle range. Just coincidence they matched your yaw P. Pretty cool, glad it’s worked out.

BTW – Please post all your PID settings so others can use them as a starting point. Thanks!

[yumemi5k]

//This is a tribute to the duplicate post detector.
My TX off failsafe RTH test on 2p3p0tf0p5 ended in crash. The drone entered failsafe and started to RTH correctly, but all motors stopped dead the moment when failsafe ended. Craft stayed armed according to logs, it’s unlikely that I disarmed the craft myself by mistake. The motor spun again erratically for a few moments during the descent.

What I recalled and saw from the logs:
1. The craft exited FS RTH into POSHOLD, POSHOLD realized something was wrong and increased throttle gradually, but motors refused to spin.
2. Right before crashing I switched into acro, which did seem to behave correctly, but it was too late for me to save the craft.
3. I entered POSHOLD after F/S at 0 throttle when all motors stopped dead, pushing throttle stick up caused motors to start spinning again. The zero throttle input was not intentional, but I expected POSHOLD to be still able to maintain attitude instead of dropping like a rock.

Is there something that could bypass navigation mode throttle request and override motor output to be min value? MOTOR_STOP comes into mind, but I don’t know about its behaviour, and AFAIK I don’t have it enabled.

Anyway, should this remain unsolved, if any of you want to test F/S, be vigilant and test POSHOLD behaviour at zero throttle first.
//

Attachments:

1. 

   1.jpg
   

[billyd]

I tried to post my pids but the post disappeared when I tried to add a photo. I tried to post it again and it won’t show. Is that what you mean by duplicate post detector? Because it doesn’t work right.

[yumemi5k]

@billyd Yes, editing posts with attachments can lead to erratic behaviour. I just lost mine by messing with attachments and had to post again. You can bypass the duplicate post stopper by adding some text before and after your post.

[billyd]

@yumemi5k Thanks for the tip, appreciate it. I will re-post later today I’m at work right now. Fortunately I was able to use the back function on my browser last night and copy paste the post into a text file on my home computer (after the forum removed it). Because it was a fair amount of information and took awhile to get it all together.

[billyd]

@yumemi5k Go over your advanced tuning settings carefully. You may have something set wrong in there.

[yumemi5k]

@billyd Good point, especially since I had a few parameters corrupted previously which were fixed manually. I’ll reflash and see if the corruption happens again and test zero throttle POSHOLD behaviour but probably won’t take the leap of faith and test ending F/S RTH with POSHOLD again.

[billyd]

FYI I just saw on youtube INAV 2.4 was released today and one of the things they changed/improved was low throttle on navigation. So that might be directly related to the issue you had…

[billyd]

Back by popular demand, ok maybe just because it got deleted by the duplicate post filter…..

Here are my INAV pids before and after triflight is enabled.

Couple of caveats:
My tricopter LR is heavy. I have a full nav setup and I use a 3sx6200mah lipo. The AUW is 864.3 grams.
Also I am using a 22HV tail servo on 6v. It’s an 8v servo and alot faster than the 210 even when only driven at 6v. I have also removed the stock emax motors and switched to hobbywing 2306 1600kv motors.

Finally this copter is designed for long range flight not freestyle racing and tuned as such.

So with that in mind here are the PIDs that worked well on my tricopter prior to enabling triflight in INAV

set mc_p_pitch = 26
set mc_i_pitch = 15
set mc_d_pitch = 15
set mc_p_roll = 18
set mc_i_roll = 12
set mc_d_roll = 10
set mc_p_yaw = 100
set mc_i_yaw = 23
set mc_d_yaw = 1

After triflight was enabled and after I ran airborne autotune, I had to increase the P in all three axes. Here is my post tailtune/triflight enabled INAV pids and other settings: (revised 1/29/20)

set mc_p_pitch = 35
set mc_i_pitch = 50
set mc_d_pitch = 40
set mc_p_roll = 30
set mc_i_roll = 60
set mc_d_roll = 35
set mc_p_yaw = 195
set mc_i_yaw = 90
set mc_d_yaw = 1
set max_angle_inclination_rll = 700
set max_angle_inclination_pit = 700
set yaw_lpf_hz = 30
set dterm_notch_hz = 125
set dterm_notch_cutoff = 90
set nav_mc_vel_xy_i = 14
set nav_mc_heading_p = 65
set tpa_rate = 20
set tpa_breakpoint = 1650
set roll_rate = 30
set pitch_rate = 30
set yaw_rate = 30

My tailtune results: (revised tri_dynamic_yaw_minthrottle 1/29/20)

set tri_dynamic_yaw_minthrottle = 500
set tri_dynamic_yaw_hoverthrottle = 1405
set tri_tail_motor_index = 2
set tri_servo_max_adc = 2751
set tri_servo_mid_adc = 1918
set tri_servo_min_adc = 1100
set tri_tail_motor_thrustfactor = 112
set tri_tail_servo_speed = 634

Hopefully these will work well as a starting point, but again if you tricopter is much lighter it might not help much.

Attachments:

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   tricopterLR_INAV_p5Triflight-1.jpg
   

[jihlein]

It was relatively easy to merge 2.4 with 2.3. I’ve got it loaded on my TriLR and it behaves on the bench. I did do a diff/save before reloading the firmware, then did a load/save of the old configuration after loading.

Don’t know if I’ll have time to fly it this weekend, you guys want the firmware?

[billyd]

Yes absolutely I’ll take it. I am also seeing some strange behavior with position hold and the throttle. Hadn’t noticed it before. But I’ve been working on so many parameters it’s easy to miss. 2.4 is supposed to correct this I believe.

ps I increased P and I for yaw even further as I noticed some drift in today’s flying. I edited the post above.

I also lowered I by one point to 14 on the velocity xy in the GPS section. That helped with some overcorrection I was getting in position hold leading to constant small slow movement. Not toilet bowl because it wasn’t increasing. Just a constant little circle not getting bigger or smaller. Lowering the I seemed to help it quite a bit. I might go to 13 and test again.

[jihlein]

Here you are….

Like I said, quick bench test only, so go over it carefully before flying. I’ll try to get out with it too, even if it’s only some PID tuning work in the backyard.

Attachments:

1. 2p4p0tf0p5.zip

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