Speed in GPS mode seems slow

[Ed209]

My forward vision isn't disabled...

This option disabled. There's even a description of the flight characteristics when enabled/disabled. You need to check with the Mavic on and connected.

 

[Mattman]

If you watch that same guy's range test vid he's getting 30mph also and his forward obstacle detection is clearly on also. As is mine.

 

[kmaluo]

If you watch that same guy's range test vid he's getting 30mph also and his forward obstacle detection is clearly on also. As is mine.

Yeah, but is he getting 30 mph in both directions? I don't think so.

 

[Mattman]

Sure is. Try watching it.

 

[kmaluo]

Sure is. Try watching it.

You're right! I'm stuck at 22. I wonder if it's a software glitch.

 

[Mattman]

Yeah pretty crazy. I don't understand how we can all be on the same firmware, same DJI go version, but getting different speed readouts. Ant chance we're actually getting different actual speeds too?

 

[GadgetGuy]

You're right! I'm stuck at 22. I wonder if it's a software glitch.

It's supposed to be 22mph. Obstacle avoidance is unable to work successfully at speeds above that, at least on the P4 (no Mavic in hand yet...)

 

[kmaluo]

During a flight today, I noticed the HSpeed on the GO app was always 20 to 50 percent higher than the speed on the controller. Must be a bug. The controller speed seemed more accurate and aligned with posted specs.

 

[GadgetGuy]

During a flight today, I noticed the HSpeed on the GO app was always 20 to 50 percent higher than the speed on the controller. Must be a bug. The controller speed seemed more accurate and aligned with posted specs.

I've seen that posted elsewhere, too! Hopefully soon to be fixed in a DJI Go update. "Man who wears two 'watches' never knows what time it really is!"

 

[Ed209]

I've seen that posted elsewhere, too! Hopefully soon to be fixed in a DJI Go update. "Man who wears two 'watches' never knows what time it really is!"

Hahaha is that an ancient DJI proverb???

 

[GadgetGuy]

Hahaha is that an ancient DJI proverb???

Apparently by having two compasses and two IMU's in the P4 and Mavic, DJI seems to disagree!
Oddly, if they are both each calibrated together at the same time, if the calibration itself was off, they will both still be wrong! One good calibration is better than two bad ones! It is not the failure of the compass or the IMU that causes issues. It's the calibration itself that is usually at fault!

=======

Segal's law is an adage that states:

"A man with a watch knows what time it is. A man with two watches is never sure."[1]
The mood of the saying is ironical. While at a surface level it appears to be advocating the simplicity and self-consistency obtained by relying on information from only a single source, the underlying message is to gently question and make fun of such apparent certainty – a man with one watch can't really be sure he knows the right time, he merely has no way to identify error or uncertainty.

Nevertheless, the saying is also used in its purely surface sense, to caution against the potential pitfalls of having too much potentially conflicting information when making a decision.

In reality a man possessing one watch has no idea whether it is the correct time unless he is able to compare it to a known standard, in which case he effectively has more than one watch.[2] This situation is not made any worse by having two watches. One might even think that it is better since if the two watches are in approximate agreement one might assume that both are working and an average of them will yield the correct time to within some accuracy depending on the specification of the timepieces. While this is true, the probability of knowing the right time is still exactly the same as with one watch.

 

[DarkEnergy]

Apparently by having two compasses and two IMU's in the P4 and Mavic, DJI seems to disagree!
Oddly, if they are both each calibrated together at the same time, if the calibration itself was off, they will both still be wrong! One good calibration is better than two bad ones! It is not the failure of the compass or the IMU that causes issues. It's the calibration itself that is usually at fault!

=======

Segal's law is an adage that states:

"A man with a watch knows what time it is. A man with two watches is never sure."[1]
The mood of the saying is ironical. While at a surface level it appears to be advocating the simplicity and self-consistency obtained by relying on information from only a single source, the underlying message is to gently question and make fun of such apparent certainty – a man with one watch can't really be sure he knows the right time, he merely has no way to identify error or uncertainty.

Nevertheless, the saying is also used in its purely surface sense, to caution against the potential pitfalls of having too much potentially conflicting information when making a decision.

In reality a man possessing one watch has no idea whether it is the correct time unless he is able to compare it to a known standard, in which case he effectively has more than one watch.[2] This situation is not made any worse by having two watches. One might even think that it is better since if the two watches are in approximate agreement one might assume that both are working and an average of them will yield the correct time to within some accuracy depending on the specification of the timepieces. While this is true, the probability of knowing the right time is still exactly the same as with one watch.

That's why a minimum of three watches are needed.

 

[GadgetGuy]

That's why a minimum of three watches are needed.

Exactly! Like three contractor bids, throw out the low and the high, and take the one in the middle! He still won't show up on time, or finish on schedule, because he uses a sun dial with a built-in "surf's up" extension! But I digress...

 

[Mattman]

DBSs vid here demonstrates a flight that calculates to an avg of 30mph (11.4 miles in 23 minutes).

Not sure if obstacle avoidance is turned on, but it's not in sport mode and it's in RTH it seems on the way back at least for when it turned around as seen on the screenshot. This supports the suggestion that some mavics actually are getting 30mph instead of 22...

 

[GadgetGuy]

DBSs vid here demonstrates a flight that calculates to an avg of 30mph (11.4 miles in 23 minutes).

Not sure if obstacle avoidance is turned on, but it's not in sport mode and it's in RTH it seems on the way back at least for when it turned around as seen on the screenshot. This supports the suggestion that some mavics actually are getting 30mph instead of 22...

Awesome link! Great find! It's already been done! Battery mod and transmitter mod! Now if I only had my Mavic already! on the way out, he flew into the wind, likely with OAS off, in order to get 30mph average. He then used RTH to turn around quickly, and used the tail wind to fly faster, while enabling OAS on the way back, as it is on during landing, and at his RTH location.

 

[flabombarda]

This post is directly related to another I posted today.

Can someone confirm that in P-Mode (front vision disabled) I can get up to 58Km/h and this is the setup for best flight time/distance ?

Using Sport mode, the longest flight I have so far was 14:55 min and 8.8 Km.
This flight consumed 75% of the battery.

Thanks

 

[GadgetGuy]

This post is directly related to another I posted today.

Can someone confirm that in P-Mode (front vision disabled) I can get up to 58Km/h and this is the setup for best flight time/distance ?

Using Sport mode, the longest flight I have so far was 14:55 min and 8.8 Km.
This flight consumed 75% of the battery.

Thanks

It certainly is not the most efficient mode! It is the worst! It burns through the battery far faster than with obstacle avoidance turned on, which is the most efficient mode for battery life and total distance! Don't use Sport Mode to make it home before the battery dies, even into the wind. Ask me how I know!

 

[MrMavic]

How did DJI fuse the Speed readings? Why did they lie about top speed? There's no way you were doing 55MPH. more like 30 max.

 

[larkin]

It certainly is not the most efficient mode! It is the worst! It burns through the battery far faster than with obstacle avoidance turned on, which is the most efficient mode for battery life and total distance! Don't use Sport Mode to make it home before the battery dies, even into the wind. Ask me how I know!

I believe that's only half true. Sport mode is for sure the least efficient but the most efficient is non sport mode but with the OA turned off. In that mode, full ahead hits max efficiency.

 

[GadgetGuy]

I believe that's only half true. Sport mode is for sure the least efficient but the most efficient is non sport mode but with the OA turned off. In that mode, full ahead hits max efficiency.

Depends upon what you mean by maximum efficiency. Are we talking longest flight time on a single battery, or most distance covered in a single flight? They aren't necessarily the same. Longest battery life is achieved with OA turned on, but severely limits distance because of the top OA speed of 20pmh on the Mavic (30mph on the P4P). Longest distance is achieved with OA turned off at roughly 31mph with no wind. You need to dial back the max speed with OA turned off to 31mph for longest total flight distance, instead of full throttle at 34mph. The long distance flyers have carefully worked out the most efficient speed on each aircraft to maximize distance, which is generally not the longest total flight time.