Spontaneous 40' ascend with no input
- Thread starter John Locke
- Start date
Nice views from up there I bet.
Thanks for posting your logs dude, seeing more data helps me analyse mine
think it's time we had some more analysis tools, much data in the .txt that I think isn't interpreted at this point in time.
Thanks for posting your logs dude, seeing more data helps me analyse mine
think it's time we had some more analysis tools, much data in the .txt that I think isn't interpreted at this point in time.
As a helicopter pilot that's not so strange really, it seems likely the auto pilot is just doing its best to accommodate your inputs and GPS/baro data. Try slowing down to a hover more slowly in front of you and watch if it loses or gains altitude depending on how fast you put the brakes on or wind direction or your aircraft heading (as opposed to track or line of flight). It's dealing with all of that plus gravity and the aerodynamics, inertia and gyroscopic properties of 4spinning rotors... And doing all that in real time with winds and radios frequency latency/interference.... Just slightly amazing to me. A bit of altitude variance of a few feet to me seems normal and I try to antiicipate it when making rapid control changes.
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Agree, but P3 don't drop height/altitude. It flies perfect under all condition (almost like an S92 or EC 225).
ianwood
Taco Wrangler
Yes. This happens on big X8 rigs a lot. Very disconcerting if you're not used to it. It has mostly to do with the barometer getting into the prop wash and thinking it's higher than it is. This can be dialed out by the manufacturer in the FC especially on a RTF system like the P4.
Sure, all P4s come with an RC. Mine doesn't work to my satisfaction. The older inspire radios GL658A have better transmit power which helps provide a better control signal. I can't explain it but for some reason it also helps with longer distance for video too, not sure why. All I can tell you is I can go over two miles with stock antenna (no surfer) now and I don't lose control signal first anymore.
With my stock P4 RC I lose control signal first, all the time at moderate distances of 3000 to 4000' over water in almost ideal environments (using channel 30, 4mbps). Most the time it loses control signal for a couple seconds but sometimes longer which triggers RTH. My P3p never did that, ever! With P3 I always get a weak video signal first, usually more than two miles away. If I lost video feed I would still have control of the craft. I would simply ascend 50' to get the video feed back. I got very annoyed with my P4 losing control signal so much. I'm thinking there's something wrong with the RC, but it could be the fact they weakened the radio performance in the P4 RC. Do other P4 pilots get this behavior at 4000' distances in ideal conditions?
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I fly a P4 with Inspire "C" RC, never had a problem, on maiden flight I went more than 7mi round trip no problem.
Was the camera facing you and were you in the center of the image...? When was the last time you received a good looks compliment?..Don't blame the drone...
Was the camera facing you and were you in the center of the image...? When was the last time you received a good looks compliment?..Don't blame the drone...
What was your reason for using the Inspire controller with your P4? Same as mine?
When I bought the P3P, (since I baby all my toyz) I discovered a problem with the P3P RC (long story, need to write a 416 pages book to explain) and I bought an Inspire type C RC that I used ever since on my P3P.
- feels better
- looks nicer
- built better
- HDMI output
- more Tx/W output.
The P3P is up for sale now (without RC) but kept the Inspire RC to use on the P4.
- feels better
- looks nicer
- built better
- HDMI output
- more Tx/W output.
The P3P is up for sale now (without RC) but kept the Inspire RC to use on the P4.
I just got back from flying my P4 with inspire rc. The spontaneous ascents and descends are reproducible. Next time I fly I'll bind the craft to my P4 RC and see if it continues. I think somethings is wrong with the barometer sensor, it's acting very strange. When I land and get close to ground the craft is solid as a rock, likely using vps for altitude.
Another strange thing is in P mode with OA enabled the craft didn't want to descend. Full down left stick and it would just sit there 60' in the air. When I switch to S mode it responded fine, with vigor. I had never seen that before when P mode acted so strange.
Another strange thing is in P mode with OA enabled the craft didn't want to descend. Full down left stick and it would just sit there 60' in the air. When I switch to S mode it responded fine, with vigor. I had never seen that before when P mode acted so strange.
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One minor issue with using Inspire RC on P4 is that the RC generic is not displayed in GO app - about - generic info but there is no alarm ti update generic. Have tried all settings and uploads and still the same. With original P4 RC the RC generic is displayed so I know I have the latest.
So I finally got around to flying a test mission to reproduce the 40' YOYO anomaly with my craft. I'll have the DATA file shortly.
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So I finally got around to flying a test mission to reproduce the 40' YOYO anomaly with my craft. The DAT file can be downloaded here. (I posted the wrong link before, 30min ago). I haven't used any deciphering tool with DAT files, only flight log .txt files. Can someone provide a link where I can upload this 103MB file and analyze the data?
I just created a ticket with DJI and sent them this file. They said they would be sending it to China for analysis. Seems strange they can't do that analysis in Carson, CA where they are repaired. Their first response is to redo the IMU calibration. I've done that and will take it out this weekend. I don't expect that to improves things, but I hope I'm wrong.
This flight for the DAT file above was very strange. The first anomaly starts at about 2:13min into the flight while in P-GPS mode when I'm hovering in one place, it goes up and down about 40' with no stick input. Then I decide to switch to S mode at 3:14 and make a hot lap around to hopefully get the system to clean itself up in S mode. I wanted to see if this anomaly was mode specific. I came back in front of me to hover again, then at about 4:30 in S mode the same behavior occurs, going up and down 40 to 50' with no stick input.
So after these two spontaneous ascent/descent events I decided change modes again at 5:05 back to P-GPS mode and come in to land because this craft is acting whacky. On the way back at around 5:35 or 5:45 I’m trying to descend with full down left stick and it won’t descend in P-GPS mode, which is very strange, I've never experienced that before. So at 5:50 I switch back to S mode which allowed me to descend like normal and land.
Note, when I’m low to the ground within 25’ I have not seen the craft go up and down randomly, I’ve only had this happen when it’s above 60’. I think VPS is preventing the erratic up/down behavior when less than 30’ AGL.
Another abnormal thing about this craft is P-GPS with OA enable will only do about 13 to 15mph with no wind. I've had it up to 19mph going with the wind, but that's cheating. OA doesn't seem allow my craft to go the max speed of 22mph like others have reported. Hence, I rarely use OA on this craft being so slow.
Here's the Healthydrone analysis based on the .txt file.
Here's Msinger's log reader data.
I just created a ticket with DJI and sent them this file. They said they would be sending it to China for analysis. Seems strange they can't do that analysis in Carson, CA where they are repaired. Their first response is to redo the IMU calibration. I've done that and will take it out this weekend. I don't expect that to improves things, but I hope I'm wrong.
This flight for the DAT file above was very strange. The first anomaly starts at about 2:13min into the flight while in P-GPS mode when I'm hovering in one place, it goes up and down about 40' with no stick input. Then I decide to switch to S mode at 3:14 and make a hot lap around to hopefully get the system to clean itself up in S mode. I wanted to see if this anomaly was mode specific. I came back in front of me to hover again, then at about 4:30 in S mode the same behavior occurs, going up and down 40 to 50' with no stick input.
So after these two spontaneous ascent/descent events I decided change modes again at 5:05 back to P-GPS mode and come in to land because this craft is acting whacky. On the way back at around 5:35 or 5:45 I’m trying to descend with full down left stick and it won’t descend in P-GPS mode, which is very strange, I've never experienced that before. So at 5:50 I switch back to S mode which allowed me to descend like normal and land.
Note, when I’m low to the ground within 25’ I have not seen the craft go up and down randomly, I’ve only had this happen when it’s above 60’. I think VPS is preventing the erratic up/down behavior when less than 30’ AGL.
Another abnormal thing about this craft is P-GPS with OA enable will only do about 13 to 15mph with no wind. I've had it up to 19mph going with the wind, but that's cheating. OA doesn't seem allow my craft to go the max speed of 22mph like others have reported. Hence, I rarely use OA on this craft being so slow.
Here's the Healthydrone analysis based on the .txt file.
Here's Msinger's log reader data.
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So after I re-calibrated my P4 IMU today I took it out to test this afternoon. Using the Inspire RC I could reproduce the same 40' YOYO effect fairly quick, the IMU calibration didn't change anything. For the second flight I linked it to the original P4 RC which I haven't flown with for weeks. It seemed to fly OK initially, but after about 13 minutes of flight, while in a hover, the YOYO reproduced again using the P4 RC, going up and down about 40 to 50' with no stick input. This craft definitely has something wrong with it, likely the barometer. Components do fail, that's why we need to be careful where we fly, for safety.
The strange thing I noticed just after the YOYO occurred on this 2nd flight, the craft seems a little unstable for a Phantom, which usually hovers rock solid. It was only about 50' away from me when I saw it shake, like a gust of wind hit it, but there was practically no wind. It was twitching slightly. I honestly thought it was going to do something out of my control, it almost seemed possessed. I got it down OK though without a hitch.
I got a reply from DJI saying they're sending my DAT file to China for analysis. Seems strange to me they need to send it to China, instead of confirming my report in California and simply issuing an RMA for the repair. To me it implies they may have a collection of these type of incidents they want to compare.
The strange thing I noticed just after the YOYO occurred on this 2nd flight, the craft seems a little unstable for a Phantom, which usually hovers rock solid. It was only about 50' away from me when I saw it shake, like a gust of wind hit it, but there was practically no wind. It was twitching slightly. I honestly thought it was going to do something out of my control, it almost seemed possessed. I got it down OK though without a hitch.
I got a reply from DJI saying they're sending my DAT file to China for analysis. Seems strange to me they need to send it to China, instead of confirming my report in California and simply issuing an RMA for the repair. To me it implies they may have a collection of these type of incidents they want to compare.
Do you always fly at the exact location and have those yoyo effects?
Have you try to go 30 miles away and take both RC with you, in an open space far away from any interference?
I have a friend on the west side of town, at his house the drones P3P P4 Inspire can not be controlled, they go crazy.
Have you try to go 30 miles away and take both RC with you, in an open space far away from any interference?
I have a friend on the west side of town, at his house the drones P3P P4 Inspire can not be controlled, they go crazy.
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