Only 6 miles per hour backward? Pilot error I am sure...

rmb

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I was hired to do a little work for a local film being made here in town.

I was on a straight stretch of road flying in Course Lock backwards in front of a Jeep (about 20-30 ft in front). And no matter what I did I could not get that PH4P to go faster than about 8 or 10 mph. After fooling around with and disabling a variety of obstacle sensors it seemed to make no difference and would not stop beeping and showing the front obstacle warning. Anyway after about 45 minutes of this I put it away and pulled out my trusty PHP. Nailed it in 2 takes.

As I am sure this is pilot error, I am going to start scouring the manual for what sensors might be the issue, but in the meantime wondered if this sounded familiar to anyone.

BTW: if my description of what I was trying to do was not clear, here is a very short ungraded 8 sec clip of the successful PHP footage that I could not achieve with the PHP4


Thanks a bunch.

R
 
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I have tried anything like this yet with mine. But I do know that the sensors are pretty picky about wanting to stop for sure. But if you turned all of the object avoidance off then it should have been good to go I would think. There is also a narrow sensing function for tighter flying through and around objects but again I need to try that too. You did mean you shot it with your P4 didn't you? Not the PHP?
 
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I was hired to do a little work for a local film being made here in town.

I was on a straight stretch of road flying in Course Lock backwards in front of a Jeep (about 20-30 ft in front). And no matter what I did I could not get that PH4P to go faster than about 8 or 10 mph. After fooling around with and disabling a variety of obstacle sensors it seemed to make no difference and would not stop beeping and showing the front obstacle warning. Anyway after about 45 minutes of this I put it away and pulled out my trusty PHP. Nailed it in 2 takes.

As I am sure this is pilot error, I am going to start scouring the manual for what sensors might be the issue, but in the meantime wondered if this sounded familiar to anyone.

BTW: if my description of what I was trying to do was not clear, here is a very short ungraded 8 sec clip of the successful PHP footage that I could not achieve with the PHP4


Thanks a bunch.

R
Since you got a front obstacle warning, it seems you were too close to the car at the speed you were going, and the p4p was actively breaking in an effort to help. A solution here would be to go into sports-mode.
 
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Since you got a front obstacle warning, it seems you were too close to the car at the speed you were going, and the p4p was actively breaking in an effort to help. A solution here would be to go into sports-mode.
Hey Tomas, the P4P will fly at 30mph with sensors on or off. So if he turns them off it should fly this scene like cake in P Mode without being slowed down! Jeep was only going maybe 20 at most in that scene. His sensors are not turning off and your right. Being so close in the front is still being slowed by sensors. Sport mode would work too but it would be a little bit harder to fly it smooth in sport mode I would think. I def should turn off the sensors in Sport Mode though.
 
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Hey Tomas, the P4P will fly at 30mph with sensors on or off. So if he turns them off it should fly this scene like cake in P Mode without being slowed down! Jeep was only going maybe 20 at most in that scene. His sensors are not turning off and your right. Being so close in the front is still being slowed by sensors. Sport mode would work too but it would be a little bit harder to fly it smooth in sport mode I would think. I def should turn off the sensors in Sport Mode though.
Edit: I'm pretty sure you cannot engage the automatic modes (such as course lock) with the sensors turned off, but I could be wrong. You are right that it should otherwise be possible to use P mode with forward and backward-facing sensors off. With S mode, they are off regardless.
 
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The downward facing sensors are not used for object avoidance.
 

rmb

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Thank you all for the input!
Here is where I continue to be confused where the sensors are concerned. If the front obstacle avoidance sensors were the issue and I was trying to fly backwards at full speed, wouldn't you think the phantom would do everything he could to back farther away from the obstacle as quickly as possible? Literally if my driver had speed up I could not have gotten out of the way without doing a rapid ascend. Also as a point of clarification the jeep was doing 15 mph.
 
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Thank you all for the input!
Here is where I continue to be confused where the sensors are concerned. If the front obstacle avoidance sensors were the issue and I was trying to fly backwards at full speed, wouldn't you think the phantom would do everything he could to back farther away from the obstacle as quickly as possible? Literally if my driver had speed up I could not have gotten out of the way without doing a rapid ascend. Also as a point of clarification the jeep was doing 15 mph.
Since you got the warning from the sensors, this was evidently what happened. The drone is intelligent, but not that intelligent (yet). Active Track will be able to recognize a moving object but that is through image analysis (from the main camera) and not using the sensors alone.

You have here simply reached a limit of what the obstacle avoidance can provide, and will have to get around it (by disabling it).
 
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rmb

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So to be clear. If the ph4p sees an obstacle ahead of it, it will limit the speed going backwards to avoid it? Is it me or does that make no sense? Or did I misunderstand your post?


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I have noticed in P-mode with or without OA enabled, controls are significantly dampened (i.e. reduced speed, slower turns/) when I'm near the ground. Seems like I have to get about 8-10 ft off the ground before it opens up a bit..

This could have been a contributing factor in your situation regardless of the OA warnings. I haven't tested it but I assume it's not the case in sport mode. I couldn't find anything about this in the manual when discussing P-Mode, but I could have missed something.
 
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rmb

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Interesting idea misterCB. I would say that I was about 12 ft AGL, but will check the logs.

I guess the big question here is regardless of what is causing this, is there a workaround? It would be sad if I had to deliver my clients the php footage vs the ph4p's superior image quality because of the higher-tech ph4p defeats these kind of flights.


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So to be clear. If the ph4p sees an obstacle ahead of it, it will limit the speed going backwards to avoid it? Is it me or does that make no sense? Or did I misunderstand your post?
The problem is simply that obstacle avoidance kicks in due to the distance to the car, and this causes the warnings and the slowing down (based on your description). The solution is either to a) increase distance or b) disable the sensors.
 

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Thanks all. I will try that. I did check my flight records and the max speed that it would allow me to achieve was a whopping 5.6 mph.

Last sill question. If it was in fact the front obstacle avoidance system, if my driver had speed up, would he have been able to hit it or would it have flown backwards at a greater speed. I am thinking not as I was in course lock. I dug very deeply into the ph4p manual this am and I must say that the only thing more frustrating then this issue is DJI's ability to write a competent manual. Sigh...


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If it was in fact the front obstacle avoidance system, if my driver had speed up, would he have been able to hit it or would it have flown backwards at a greater speed. I am thinking not as I was in course lock. I dug very deeply into the ph4p manual this am and I must say that the only thing more frustrating then this issue is DJI's ability to write a competent manual. Sigh...
The manual is extremely brief and not worth much here, unfortunately.

This is a good question, but I have not seen any tests of this (it would be interesting to see the results, however).

The chances of a crash here are definitely present, so I would be prepared to increase height immediately if flying under such demanding conditions.
 
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My bet is that just because it is close enough to set off the front sensors that it automatically slows everything down in every direction no matter what direction you are flying. But, those front and back sensors should be able to be turned off. But maybe mister CB is right that is an ground or alt reltated effect? I have just always noticed that anytime I get the sensor beep that everything about the bird slows down and sometimes has like a racheted effect as it goes on its way.
 
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By default the drone will not fly backwards to avoid an object coming towards it. You have to turn that option on. Did you do that?

If anything it looks like rear object avoidance was triggered and that's why it stopped. Also it looks like you are going faster than 5mph in the video...

Can you upload the txt log for the flight here then post the link? https://www.phantomhelp.com/LogViewer/upload/
 

rmb

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Thanks KevMo. I think you my be on to something.
 

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By default the drone will not fly backwards to avoid an object coming towards it. You have to turn that option on. Did you do that?

If anything it looks like rear object avoidance was triggered and that's why it stopped. Also it looks like you are going faster than 5mph in the video...

Can you upload the txt log for the flight here then post the link? https://www.phantomhelp.com/LogViewer/upload/
Never uploaded a a log. If you want to walk me through it I would be happy to. Regarding the speed, the clip you saw was the successful shot that I did with my PH4 that I had to use when the PH4P was giving me trouble. Also as I remember the fly backwards option was on, but most likely over ridden by course lock. Regarding he rear object avoidance there was nothing behind it until it got close to me. Anyway If you think you can easily walk me through the flight log upload I will do that.
 
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Never uploaded a a log. If you want to walk me through it I would be happy to. Regarding the speed, the clip you saw was the successful shot that I did with my PH4 that I had to use when the PH4P was giving me trouble. Also as I remember the fly backwards option was on, but most likely over ridden by course lock. Regarding he rear object avoidance there was nothing behind it until it got close to me. Anyway If you think you can easily walk me through the flight log upload I will do that.
Ah I misunderstood the video was from the p4. I would still guess this is obstacle avoidance related given the surroundings and the fact it didn't occur on p4 but did on p4p makes me think that is the case. OA is not perfect and can have false positives or pick up something to the side but think it's in front.
 
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So to be clear. If the ph4p sees an obstacle ahead of it, it will limit the speed going backwards to avoid it? Is it me or does that make no sense? Or did I misunderstand your post?


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I absolutely agree. It can not be because of the Jeep following the P4P that is completely counterproductive and counterintuitive. Also insane "smarts" programming.


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