ACRO bug (fixed in 2.9.1b): while doing flips in ACRO mode, if you switch to Stabilize while inverted your throttle will go to minimum. To regain throttle control you need to switch back to ACRO then back to Stabilize again (i.e. switch to stabilize twice). You never lose control of roll/pitch/yaw.
Loiter/AltHold/Auto/RTL bug: if you switch into these modes with throttle at zero motors will go to minimum until you raise the throttle.
Auto mode altitude bug (fixed in 2.9.1b): setting a waypoint altitude greater than 320m over home altitude may wrap around and instead be interpreted as a low altitude.
ArduCopter 2.9 is now in the mission planner and the downloads area!
The major improvement is we use inertial navigation to improve altitude hold. This increased reliance on the accelerometers means you must do some additional set-up before flying:
1. Perform the new accelerometer calibration in the mission planner (video). The auto-trim metho has also changed (video).
2. Add vibration dampening foam between your frame and the APM. Some suggested materials: DuBro, gel, hk foam.
3. If upgrading from 2.8.1, modify the throttle and altitude PID values:
- Increase your Throttle Rate P, reduce I to zero, increase D
- Increase Altitude Hold P, reduce I to zero
- Tune Throttle Accel P and I terms but try to keep P about 1/2 the size of I
Here is the list of major changes (a more detailed list can be found in the release notes):
- Alt hold using inertial navigation (Leonard, Randy, Jonathan)
- AUTO_VELZ_MIN, AUTO_VELZ_MAX parameters control the max climb/descent rate for the autopilot (cm/s)
- PILOT_VELZ_MAX controls max climb/descent rate for the pilot (in cm/s)
- Landing improvements (Leonard/Randy). Copter will descend to 10m or until an object is sensed with the sonar. Then slows to 50cm/s descent (speed can be adjusted with LAND_SPEED parameter). (video).
- Surface tracking with sonar (Randy/Leonard). Copter will attempt to maintain current distance from objects in front of sonar regardless of altitude. Only used in alt-hold and loiter, not used for missions. Sonar can be enabled/disabled with CH7 switch. (video)
- Failsafe improvements (Randy/Craig/John Arne Birkeland) including bug fixes, additional check for PPM encoder failure and implementation of battery failsafe. Set-up instructions are here.
- Mediatek gps driver accuracy improvements and use of SBAS [Craig]. Instructions on upgrading your mediatek to firmware 1.9 are here.
- Traditional Heli improvements (Rob) including (a) bringing heli code back into the fold, (b) enabled rate controller (previously only used angle controllers). (c) fix to rotor speed controllers - now operates by switching off channel 8. (d) allow wider collective pitch range in acro and alt hold modes vs stabilize mode (e) bug fix to allow collective pitch to use the entire range of servos
- Acro trainer (Leonard). Copter will return to be generally upright if you release the sticks in acro mode.
- ACRO_TRAINER : set to 1 to enable the auto-bring-upright feature
- ACRO_BAL_ROLL, ACRO_BAL_PITCH : controls rate at which roll returns to level
- Camera control improvements (Randy/Sandro Benigno): (a) AP_Relay enabled for APM2 (b) Trigger camera with CH7 or DO_DIGICAM_CONTROL command (c) Allow pilot override of yaw during missions and fixed CONDITIONAL_YAW command.
- PPM sum support for transmitters with as few as 5 channels (Randy/Tridge/John Arne Birkeland).
- Performance and memory useage improvements (Tridge).
As per usual PIDs are optimised for the 3DR/jDrones quad with 850 motors and 10" props. If you're using more powerful motors/props and are seeing bad flight behaviour in stabilize, start by turning down Rate Roll P in 25% steps.
Special thanks to our testing team lead Marco and the dedicated bunch on the 2.8.1 release thread who put their copters at risk while testing the pre-release version. Some of their videos are here: 1 2 3 4 5 6 7 8
Please feel free to report issues you find in the discussion below and/or add them to the issues list.
Replies
Could everybody kindly tells what APM board( version 1.4 , 2.0 or 2.5) you have when post or answer a problem?
Thanks.
No sure what issues I am having with Alt Hold. The quad - Flamewheel 450 SK3 1040KV running 10x4.5 props.
It seems over powered not matter what I do with the PIDs. I wind them right down to try and stop the high thrust bouncing but then the quad slowly sinks to the ground. Putting 8x4.5 makes it a lot better but I should be able to tune it to the bigger props.
APM 2.5
Any ideas?
I managed to get in some more flights on 2.9.1 to dial in my quad (jdrones frame, 880Kv motors, 30A ESCs and 12 x45 props) today with mixed results. The weather was not too bad with slight winds and gusting a little later during my second flight and then calmer conditions on the third (last flight). I have recently posted my calibration results, initial PIDs and graphs showing the RAW accel values which indicate z is ok with some slight noise (tolerable on x/y)
My first flight was good in Stablize mode and then in loiter I did not have to touch the radio until the very end with some drift off the original position as the wind picked up. This was very encouraging. Even though I had no ALT hold on, I was not touching the throttle. I analyzed the logs after to see the number of satellites and check GPS data for the very end when the quad drifted. I had no less than 9 SATs, good lock and towards the end 11 SAts. I am using the MTK GPS with v 1.9 code.
The second flight was very disappointing. I had good control in stab mode but was unable to hold any position using Loiter mode. In several instances the quad moved off position consistent with the wind direction and in two specific instances moved very quick off position after engaging Loiter. I had to reengage stab mode to gain control. I again checked GPS data and maintained solid lock and around 11 SATs So I do not suspect any GPS issue. It would seem Loiter mode is ok in very calm conditions but unable to maintain hold in slight winds / slight gusty conditions.
I changed my PIDs as follows from my last flights, for today's testing, but have yet to change the Loiter parameters from the defaults in 2.9.1. So maybe someone with a similar config and good loiter hold in slight to moderate winds could suggest some PID changes / advice?
On Randy's and other advice I increased the Rate P Roll and Pitch from 0.090 t0 0.12 fro today's filights. I also bumped up the " I" from 0.06 to 0.08 (Note I try to maintain original P to I ratio). I did originally reduce the Stab P roll and Pitch down from 4.5 to 3.0 and for these flights today it was on P 3.5 and IMAX from 8 to 5. Note I made these adjustments due to running 880Kv motors with 12x45. Some people have advised me to put these back on 4.5 I thought I would do this in increments. Again open to advice here.
As I say my Loiter values are default i.e Rate Loiter P 5.0, I 0.04, D 0.4 and IMAX 30.0 and Loiter Speed P0.2 I 0 etc
I am puzzled why the default Loiter values which are optimized for the 3DR Quad with 850Kv motors and 10" props would fail to keep my quad with larger motors and props from drifting off position. If anything I assumed eventually I would have to reduce the values to avoid over shoots?
My final flight confirmed the slight wind effects on Loiter. With calm conditions my quad held on position, but started drifting and did not recover when some slight breeze popped up mid flight. Another interesting effect I noticed. When holding well in Loiter my quad appeared to be rocking slightly along the roll and pitch axes. What would be the best value to change to reduce this rocking motion along pitch and roll axes while quad is not climbing or descending ie. on station in loiter maintaining altitude with no throttle input?
Now to end on a good note. I tried ALT HOLD for the first time in 2.9.1. WOW! Fantastic I switched from stab mode and loiter mode into ALT HOLD with no appreciable drop in height i.e really nice throttle calibration and end points. ALT Hold was solid; move up or down and its like the quad is stuck in the air. Very well done guys. It did not get a lot of time on ALT HOLD as the loiter drift problem keep me busy.
Sorry no logs but hoping the description and PIDs I am using might be enough for some general tuning on Loiter for larger motor quads.
Guys I did the new calibration and I see my Yaw 330 degree is this normal or it should be 0?
I value is 0 except the yaw
First I'd like to thank the entire development team for their efforts. I am fairly new to the Arducopter community only recently completing the build of my first quadcopter (APM 2.5, 3DR 900 Mhz telemetry, 3DR uBlox LEA-6 GPS, XL-EZ0 Sonar, 1100KV motors w/11" props) and have been running 2.8.1 since it was introduced. Last week when 2.9 was released I followed the recommendations to add vibration dampening of the APM 2.5 controller to get ready for 2.9. I then loaded the new release and after setting everything up very quickly thought I had an issue with my sonar as I wasn't getting the normal altitude readings I was getting with 2.8.1. Upon further reading of this thread I now see that this is because of the changes made in 2.9 and the way it handles the sonar reading to adjust the altitude value.
My question is this... How do you now validate that the sonar is functioning properly if nothing in the Mission Planner shows the direct impact of the sonar sensor reading? Would it be a good idea to add support in a future release to show the current distance being read from the sonar somewhere in the Mission Planner HUD (in addition to showing the altitude)?
Thanks again for all your efforts.
Hi,
I have been seeing problems with one of my quads, I have 3 with APM2.5's on them. One I have sonar, OF, telm (the works on) the other I just have wireless telm and gps. the one with little on it is giving me weird problems, I am not sure if it is 2.9.1 because I just built this one with new esc's and a new frame.
What happened today, it flew well, or pretty well, it is not near as stable/smooth as my other arduquad (which looks like it is sitting still in the air, it is awesome) but it flew pretty well, I tried alt hold and loiter, both did pretty well. After watching Marko's videos, I got in this habit of testing loiter by yawing fast in both directions to see how well it holds position. First thing I noticed is it didnt stop yawng as soon as I let off the yaw stick, next thing I know it is yawing on its own, I switched to stab mode and it was still yawing on its own.. I am not exactly sure what happened after that but I got it down safely, but with a couple pieces missing :).
I did repairs, and went out to fly again, same thing happened. after that I took my other quad out and tried it with 2.9.1 and it flew like champ.
If someone can tell fro my logs what, or where my problem could be coming from, please do. I am suspecting the esc's or at least the 5v's regulator from them. but I am not sure. I have gone through the log but I just dont understand enough to know where the problem is from.
thanks for any help,
.
2013-02-04 15-48-19.rar
2013-02-04 15-00-06.rar
2013-02-04 16-50-45.rar
I do have difficulties to differ all the logs, with just a number start and number end. No time stamp.
Every time you "erase" the accumulating number of logs restarts.
Any good advise to process logs an easy way. I am renaming all the time to have more control with my log archive but a lot of work.
I have enabled more or less all log parameters. Does this steal performance of the system? Where are this logs stored? How big is this memory, what happens when memory is filled up with logs? FIFO?
Thanks.
Hi Randy,
This is what I did.. As I told you that my COMPASS_OFS_Y was way too much, I reset COMPASS_OFS_X, Y and Z values to 0. Enabled the COMPASS_USE and the yaw drift i spoke about was gone. However, the COMPASS_OFS_X, Y and Z values rebuild and Y built upto -107 whcih started the yaw a little again. I am afraid that with time as the OFS will build more, the auto yaw behavior will come back
I also did auto Trim and my HUD became offset. The horizon moved up (as if the quad was going nose down) I reset using action- preflight calibration, but that reset my AHRS_TRIM_X, Y, Z to 0
Is this a bug?
I am attaching my logs. Please suggest.
2013-02-05 01-41 4.log
2013-02-05 01-41 4.log.gpx
2013-02-05 01-41 4.kmz
Guys I did the new calibration and I see my Yaw 330 degree is this normal or it should be 0?
I value is 0 except the yaw
Yesterday I had a really weird thing happen with 2.9.1rc2... actually 2 weird/bad things. I already dug into my logs and brewed some conclusions, but I wanted verify with the experts before continuing.
First, I was loitering in a hover and it randomly pitched hard to the right and back. I attempted to correct giving full forward and left stick with no apparent affect. It happened so quick I panicked, and forgot to switch to stab and punch the throttle for the save. Fortunately I was only a few feet up when it happened so it didn't go too far before crashing in the grass. Upon reviewing my dataflash logs, it's clear at the moment of departure the nav control was reacting correctly to GPS location, but for whatever reason the GPS location went the opposite of where the quad actually traveled. Is it possible for a bug in APM to cause a misinterpretation of GPS data? The departure happens @3:30 in the video... I attached the dataflash log and KMZ for visual aid (flight 1). Unfortunately I didn't have ATT on, but I think just GPS and NTUN tell the story well.
Second, I had a problem with the motors cutting off briefly when switching to loiter during an aggressive descent in alt hold... don't ask why, we were quad racing that's why. My strategy, just like I pulled off on top of the hill @7:00, was to come in fast in alt hold, then switch to loiter over the LZ, and drop straight down. Obviously that landing at the finish line was lower and more rushed than the one on the hill; I had to make up time after "over climbing" on the way to the hill. I held "throttle off" during the switch from alt to loiter, assuming there would be that usual burp in throttle, but not quite a "motors off roll" like what happened. If the motors didn't cut off for that split second it probably would've landed safe. I have my pilot max CR set to 300 and auto max CR to default (+-125). I also increased my waypoint max speed to 6m/s. These settings have worked flawless with auto and slow/tame loiter use. My theory is loiter tries to correct alt and xy position at the same time. I came in hot on all 3 axis, and loiter responded strongest to the direction of highest velocity. So instead of toning down the pitch to stop and leaving some reserve power to control the fast descent like I wanted it to do, it lurched over to stop the xy movement first, and ran out of altitude before it could right itself and correct the descent rate. This is seen in the video @7:30, and I also attached a log (flight 8) in case someone else can come to a different conclusion. Note how the altitude drops right past WPalt when the motors shut off; again sorry for no ATT or motor data.
The second problem is probably something I can fly around... mainly avoid "hooking up to loiter" so low, or at least not without slowing the descent and velocity first. I hope 2.9.2 INAV will fix this behavior. The first problem though, I sure do hope that is just more of my bad luck, because that incident really hurt my confidence in using GPS guidance at all with APM. Shame, because except for this incident it was about as close to perfection as I could ask.
flight 1.log
flight 1.kmz
flight 8.log
-
34
-
35
-
36
-
37
-
38
of 58 Next