Yesterday I had a gig, in an open field I had to follow  a truck. I told the driver to keep at 30km/h speed and I set the drone's  Normal mode to about 45km/h speed maximum. Yet in some shots the drone just didn't want to speed up even to 30km/h !  

It was struggling, speeding up - slowing down  in between 15 - 25km/h. It flew at about 6 - 8m high, so there was no obstacle around it - also the truck was at least 10m away in an angle - not in front or side....    This error ruined many shots !!!  And it wasn't rotor overload, because at the end I switched to Sport  mode and the drone rocketed and sped up immediately....  ( but it was too late, the truck had already reached the end of road and I didn't dare to shoot with obstacle avoidance turned off )

Shooting moving vehicles is very difficult in every case - checking surroundings, handling controls, composition and contacting the driver realtime .....and then this absolutely unexpected error ruins everything...
Any similar experience with this issue , guys ? Or a solution? Thanks

There are others here with more experience tracking moving objects I am sure, but in the case of the M3 not being able to keep a consistent speed, I often times found that it was indeed the OA that was slowing me up from time to time, even when really unnecessary.    I concur with you though that OA is a really essential part of the mix.  If you turn off OA, you may find that this issue goes away.

Hi there. Thank you for reaching out and we're sorry for the trouble. During the flight, the aircraft speed may not reach the maximum speed mentioned in the official manual due to flight power offset affected by environmental wind. Products with obstacle avoidance systems will actively lower their speed after the obstacle avoidance systems take effect. Sometimes, if the environmental light is too bright, the obstacle avoidance systems may recognize the light as an obstacle by mistake, thus slowing down the aircraft.

Solution

1. Please change the flight direction and try again to avoid the influence of wind or light from certain angles.
2. If the aircraft flies slowly in each direction, we recommend that you land the aircraft as soon as possible and go to another environment. We also recommend have a test flight and try in an open environment with less wind and at a lower altitude. (We do not recommend flying your aircraft too high because the higher the altitude, the greater the difference in wind power. As such, the purpose of their testing cannot be reached.)
3. Please check whether the propellers on the drone are damaged or bent. If you found it to be damaged/bent, use new propellers if possible, and try again.
4. Please check and switch the flight mode, and see if the flight speed is slow in different modes. (It is best to check the speed that can be reached in different modes.)

Hi Paladin, thanks, but I don't think that the mentioned scenario should cause this issue. here is the video. It is worth mentioning that I also have a Mavic 2 and used it for 2 years in almost every situation possible and I don't remember similar issues with it.


Watch the lower right corner , where the grass meets the edge of the road... that clearly shows the speed ramping...  Drone accelerate...slows down...accelerate ...slows down.... Wind was very mild.

Hi. Sometimes while flying over a field, forest, etc., the downward vision system is feaking out. Try changing the obstacle avoidance action from "Bypass" to "Brake". It worked for me.

a_k_o Posted at 5-25 00:04
Hi. Sometimes while flying over a field, forest, etc., the downward vision system is feaking out. Try changing the obstacle avoidance action from "Bypass" to "Brake". It worked for me.

https://youtu.be/PZ3DjCJgv9Q

Thanks !  It is always set it to Brake, so problem is sg. else...  Setting OA to Bypass makes the drone fly absolutely uncontrollable so I never switch to Bypass. ( I also have a mini3  Pro... same result with Bypass )

Hi

if you like share your flightlog for this issue.
use this > https://www.phantomhelp.com/LogViewer/Upload/
post the uploaded link on here

FlightLog might explain why the speed is fluctuating.

cheers
JJB

dronemagics Posted at 5-24 22:59
Hi Paladin, thanks, but I don't think that the mentioned scenario should cause this issue. here is the video. It is worth mentioning that I also have a Mavic 2 and used it for 2 years in almost every situation possible and I don't remember similar issues with it.

Thank you for your response and we're sorry for the trouble. Can you please try to download the DJI Assistant 2 software and please update/refresh the firmware and see if the issue persists? You may also perform the IMU calibration to ensure the stability of the unit. Please keep us posted. Thank you.

Definitely turn off OA, I run into this all the time. I can be flying 50 or more above any obstacles and the drone will constantly think it sees something and adjust speed. I fly about 90% of the time with this off. I wish you could also turn off AUTO land, that makes it impossible to land on a moving boat which I also do quite a bit. Now we have to come to a complete stop and even that is not really helful as there is always wind or current moving the boat. It is a real pain in the ass. Have no problem doing this with the Mavic 2. I can do it all day long with no issues with that drone. I have been begging DJI to fix this for some time now. Now they want me to upgrade to the Mavic 3 PRO??? As soon as you make it a true PRO machine which means put ME in control and I will.

CreativeSky Posted at 6-4 17:46
Definitely turn off OA, I run into this all the time. I can be flying 50 or more above any obstacles and the drone will constantly think it sees something and adjust speed. I fly about 90% of the time with this off. I wish you could also turn off AUTO land, that makes it impossible to land on a moving boat which I also do quite a bit. Now we have to come to a complete stop and even that is not really helful as there is always wind or current moving the boat. It is a real pain in the ass. Have no problem doing this with the Mavic 2. I can do it all day long with no issues with that drone. I have been begging DJI to fix this for some time now. Now they want me to upgrade to the Mavic 3 PRO??? As soon as you make it a true PRO machine which means put ME in control and I will.

wow. that sounds pretty bad… I also have an M2P and yes, never had this issue… but I wouldnt dare to turn off OA with such an expensive drone in a low altitude scenario like this. Dji please correct this behavior !

It happened to me last week, I was flying over water, so I guessed that the sensors were receiving reflections from the water. But there is no water in OP video. What we have in common is that I also had a moving object in the frame. To me it looks as if the active track is turned on in the background and keeps the distance from the object. Therefore, the drone accelerates and then slows down to keep the distance from the object. Seems like software bug.

Log from that flight is here https://www.phantomhelp.com/LogViewer/6J1FJ5LVHN6ZIV5M3KUD

At 3:23(and also before), you can see that I do full throttle and drone speed is constantly fluctuating from 22 mph to around 15 mph. There was no wind that day, nice and sunny weather. Flying backwards was without speed changes.