Sport mode vs normal mode, wich one is more efficient?

[alexjo55]

Is there any difference in sport mode vs normal mode when it comes to how long you can fly?
When i been flying far away and the 20% warning starts beeping, i sometimes put it in sport mode and fly as fast as i can to home.
But is this really more efficient than flying slower in normal mode?

I have not made any testing on this, but it feels like the sportmode is better to use in headwind when the normal mode can be extremly slow.
One time i was 1.5 km away and it started to blow very hard so the drone did like 1,5m/s, and when i put it in sportmode it was over 4m/s.

Was thinking the sport mode would drain the battery much faster but i dont think thats correct.

 

[rwilliam99]

Is there any difference in sport mode vs normal mode when it comes to how long you can fly?
When i been flying far away and the 20% warning starts beeping, i sometimes put it in sport mode and fly as fast as i can to home.
But is this really more efficient than flying slower in normal mode?

I have not made any testing on this, but it feels like the sportmode is better to use in headwind when the normal mode can be extremly slow.
One time i was 1.5 km away and it started to blow very hard so the drone did like 1,5m/s, and when i put it in sportmode it was over 4m/s.

Was thinking the sport mode would drain the battery much faster but i dont think thats correct.

I don't know for sure but I've read that sport mode does use battery faster which seems intuitively correct. The big question that I don't think I've seen answered is - if that is true, is the additional battery usage a net positive? Meaning - if I put it in sport mode, will it get me home sooner with less overall battery usage?

Interesting to see if anyone has any hard data on this.

 

[slup]

In general you get the most distance from your battery if using full speed in Normal mode... but thing's get more complicated if mixing in a headwind & approaching "empty tank". And it's a fact that Sport will consume more amps... you don't get the air speed increase for free.

In your example with 1,5m/s vs. 4m/s, the amp draw for Sport needs to be less than 2,7 times (4/1,5) larger than in Normal mode to be the best. So what you chose will differ with the situation...

 

[Meta4]

Is there any difference in sport mode vs normal mode when it comes to how long you can fly?
When i been flying far away and the 20% warning starts beeping, i sometimes put it in sport mode and fly as fast as i can to home.
But is this really more efficient than flying slower in normal mode?

If you need to get the most miles out of your battery, use full stick in Normal Mode.
If you want to go fast and burn through a battery fast, but not be able to go as far, use Sport Mode.

I have not made any testing on this, but it feels like the sportmode is better to use in headwind when the normal mode can be extremly slow.

That's going to depend on how much wind you have to fight, how far you need to fly and how much battery you have left.
The calculation is complex.

 

[chong67]

I believe Sports Mode and Normal is the same on the Mini 3. It only has the down sensor.

 

[slup]

I believe Sports Mode and Normal is the same on the Mini 3. It only has the down sensor.

That's not correct... both the Mini 3 Pro & Mini 3 have different max air speeds in Normal vs. Sport (10m/s vs. 16m/s).

The speed change is achieved by allowing the Mini to tilt down further in Sport than in Normal... below is how the prop generated thrust is divided between countering the gravity & providing horizontal speed. When the drone tilts forward the thrust vector that counters the gravity gets less & the thrust vector in the horizontal plane gets larger... in order to still keep the drone airborne (countering the gravity) the motors are increasing the rpm... & increased rpm consume more amps.

 

[Ralph thompson]

Theoretically speaking, sport mode is more efficient. In normal mode the controller is constantly tweaking individual props to maintain the demanded position. So a skilled operator could in theory manage a flight more efficiently. In practice, the benefit is probably small and you’ll spent a lot of time making abrupt inputs to avoid a collision and the risk is much higher.

 

[slup]

Theoretically speaking, sport mode is more efficient. In normal mode the controller is constantly tweaking individual props to maintain the demanded position. So a skilled operator could in theory manage a flight more efficiently. In practice, the benefit is probably small and you’ll spent a lot of time making abrupt inputs to avoid a collision and the risk is much higher.

Maybe I misunderstands you, but...

All modes on a drone is governed by the PID controller which for DJI most probably runs on a 8KHz loop time... so the gyro values is mainly compared to the commands (stick inputs), 8000 times every second & the FC sends RPM changes over the ESC's to alter the thrust per motor to close all deviations.

A DJI GPS drone also have at least 3 other inputs that effect the RPM calculations the FC needs to do... the horizontal hold, the set max tilt angle & the set max air speed (in ATTI mode the horizontal hold & max air speed gets deactivated, but all the rest applies).

All this can hardly be more efficient if all is left over to a human... or differ between modes.

 

[Droning on and on...]

Theoretically speaking, sport mode is more efficient. In normal mode the controller is constantly tweaking individual props to maintain the demanded position. So a skilled operator could in theory manage a flight more efficiently. In practice, the benefit is probably small and you’ll spent a lot of time making abrupt inputs to avoid a collision and the risk is much higher.

This is not correct.

@slup described the aerodynamics above well. To add some analysis, efficiency reduces directly in line with increasing speed because drag increases proportional to speed squared – there is 4x the drag force that must be countered by thrust at 10m/s than at 5m/s.

To make matters worse, the surface area cross-section normal to the direction of motion increases with increased pitch, so drag actually increases more than 4x with a doubling of speed.

To pile on even more, the higher load on the battery will cause voltage to drop (google lipo discharge curve), reaching critical battery voltage sooner, and the battery discharge in a less efficient part of it's discharge curve, shedding more energy as heat than at lower load.

So. What is the most efficient speed, that gets the longest total distance flown? I don't know. Some here have said full‐stick Normal. That's probably as good an approximation as any, however I found years ago when doing range tests with my MA1 the sweet spot was a little higher, so had to fly in S and attentively control the speed, more than max N, less than max S. I was able to get max distance out and back at that speed.

'Been years, so I don't remember the speed. And I don't do range tests any more

 

[Droning on and on...]

A DJI GPS drone also have at least 3 other inputs that effect the RPM calculations the FC needs to do... the horizontal hold, the set max tilt angle & the set max air speed

One small but very important correction to what you say above: There is no configured max  airspeed, only a max groundspeed.

The drone has no way to sense/measure airspeed, rather senses groundspeed via GPS and closer to the ground VPS, and the FC controls for that.

So, when flying into the wind, with an constant indicated speed in the DJI Fly display of 10m/s, the drone will be flying faster through the air into the wind than downwind – airspeed.

To see this, you don't even have to extract and analyze logs. Just fly with a bit of wind, and display the radar/attitude indicator in the lower left of the display. The drone is clearly indicating greater forward pitch attitude flying into the wind than with it, all the while going the same speed over the ground.

 

[Droning on and on...]

Anyone that wants to run some tests it would be of great benefit to know, as that's the speed we want to fly when getting home might be iffy.

 

[Ralph thompson]

Maybe I misunderstands you, but...

All modes on a drone is governed by the PID controller which for DJI most probably runs on a 8KHz loop time... so the gyro values is mainly compared to the commands (stick inputs), 8000 times every second & the FC sends RPM changes over the ESC's to alter the thrust per motor to close all deviations.

A DJI GPS drone also have at least 3 other inputs that effect the RPM calculations the FC needs to do... the horizontal hold, the set max tilt angle & the set max air speed (in ATTI mode the horizontal hold & max air speed gets deactivated, but all the rest applies).

All this can hardly be more efficient if all is left over to a human... or differ between modes.

Totally agree but in strong gusty winds, holding a demanded position must take a lot of energy which is over and above other considerations. This not required in ATTI or sport mode If yr bravely letting it drift along in the wind. I’ve never tested any of this since I never use sport mode (Or ATTI on the Inspire). But I’m sure it’s totally academic & depends much more on the skill of the operator. As the FAA used to say in the header of their safety bulletins to pilots, “a good pilot never gets in to a situation where he needs to use his skills”

 

[Droning on and on...]

Totally agree but in strong gusty winds, holding a demanded position must take a lot of energy which is over and above other considerations.

In a 10mph wind holding position over the ground requires nothing more or different than flying 10mph over the ground in still air.

You have to change your perspective to relative to the airmass, not the ground. Once aloft, from the standpoint of flight dynamics the only thing that exists is the body of air the drone is in. The FC will fly through that airmass in a manner necessary to position relative to the ground, but there's nothing special about hovering in terms of flight dynamics.

 

[sar104]

One small but very important correction to what you say above: There is no configured max  airspeed, only a max groundspeed.

The drone has no way to sense/measure airspeed, rather senses groundspeed via GPS and closer to the ground VPS, and the FC controls for that.

So, when flying into the wind, with an constant indicated speed in the DJI Fly display of 10m/s, the drone will be flying faster through the air into the wind than downwind – airspeed.

To see this, you don't even have to extract and analyze logs. Just fly with a bit of wind, and display the radar/attitude indicator in the lower left of the display. The drone is clearly indicating greater forward pitch attitude flying into the wind than with it, all the while going the same speed over the ground.

There is a de facto maximum airspeed because each mode has a maximum tilt angle, and airspeed is a function of tilt and density altitude.

 

[mobilehomer]

Just take a look at the RTH speed using a battery with more than 50% left. The drone will use the most efficient speed.

 

[slup]

Totally agree but in strong gusty winds, holding a demanded position must take a lot of energy which is over and above other considerations. This not required in ATTI or sport mode If yr bravely letting it drift along in the wind...

Yeah... but you're mixing the user cases a bit here. You can't compare a drone that holds position in a gusty wind (with all necessary motor RPM changes) with a drone that drifts freely with the wind in ATTI mode.

If you as a pilot should manually try to hold position in ATTI mode I bet that the "holding position" will be much worse & less efficient as you don't get direct & immediate feedback over what the drone does (gyro input) & will have a much longer delay before you tries to counter act... a counter action that also most probably isn't the correct one... & that you as a human can't repeat this feedback loop in a 8KHz speed.

 

[Droning on and on...]

There is a de facto maximum airspeed because each mode has a maximum tilt angle, and airspeed is a function of tilt and density altitude.

Yes.

However it is not a parameter in the control loop of the FC. It is simply a configured limit the FC won't exceed, like max height.

And, the vast majority of the time it doesn't come into play at all – it never ends up limiting the FC commanded pitch angle because most people don't fly when it's that windy.

 

[Droning on and on...]

Just take a look at the RTH speed using a battery with more than 50% left. The drone will use the most efficient speed.

Reference?

 

[mobilehomer]

Reference?

Logic and experience. The algorithm used must calculate the most efficient use of remaining energy to travel the necessary distance safely. Also, my 2S travels faster than Normal max and slower than Sport during RTH. Try it for yourself.

 

[Droning on and on...]

Logic and experience. The algorithm used must calculate the most efficient use of remaining energy to travel the necessary distance safely. Also, my 2S travels faster than Normal max and slower than Sport during RTH. Try it for yourself.

Oh I have. Many times with different drones. As I mentioned above, my testing experience when doing range tests determined the most efficient speed for maximizing flight distance was between max N and S speeds. RTH returns at less than max N.

So my efforts, somewhat formal, conflict with yours. Didn't see you present any logic really, just some presumptions.