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Litchi Limitation

I just tried to fly a perimeter flight of my subdivision.

Calculated flight time 11 min, distance 2.1 miles. Cruse speed 15 mph.

There is a little bit of wind, but not too much.

Drone had 98% battery at start of mission.


I lost connection after a couple of minutes. The drone was maybe 1/5 of the way around the circle. At 7 minutes, I heard the drone coming over my house, and my controller started beeping. There was a RTH alert for low battery... I didn't touch it, it reported about 20% battery. The drone flew to the home point and began to land, the controller blaring the whole time.

Once the drone landed, the battery was <10%

Plugged the drone into the Mac to d/l the video and see what was up. The drone made it approximately 1/2 way through the mission and then turned straight for home.

Actual video length 7:29 take off to land. Battery left.. almost nothing.

I have Smart Return to Home enabled and battery set to 30%, but it would have had to start the trip back well before 30%, or it would have never made it.

I may try the same path again at 30MPH to see if it can get farther around, but it is quite scary to not have control of the drone for any length of time just hoping that Litchi gets it back.

This time it did.
 
My 4 mile mission I did 33.6mph (max)
It takes getting used to - not having control or knowing.
My first 3 mile mission with over 110 seconds of "no telemetry for xxx seconds" calling out.
Had no idea I could go faster at that time :D
Total flight about 12 minutes.

You do get used to it after a while :D

Oh, and Litchi confirmed turning off Smart RTH only turns off the ability for the Spark to sense it has not picked up the controller for too long.
Turning Smart RTH does not affect low battery failsafe
 
Cool,

I increased speed to 20MPH and ran the Waypoints again. and it worked like a charm. I also had 55% battery remaining after the lap and 6:29 of recording time. I don't know what happened to the battery earlier, I must have misread it. I will have to be more careful about pulling batteries off the charger.
 
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Cool,

I increased speed to 20MPH and ran the Waypoints again. and it worked like a charm. I also had 55% battery remaining after the lap and 6:29 of recording time. I don't know what happened to the battery earlier, I must have misread it. I will have to be more careful about pulling batteries off the charger.

Congrats!
You are about to have a load of fun!
Just triple check your mission before sending it out.
 
Have you guys been able to get actual speeds during your missions over 20 MPH? I can manually fly 30+, but even setting the mission speed all the way up I stay around 20....
 
Have you guys been able to get actual speeds during your missions over 20 MPH? I can manually fly 30+, but even setting the mission speed all the way up I stay around 20....

That is correct.
My logs recorded the actual 33.6mph max for Litchi.

There are two speed settings.
On the Mission Hub app, under settings there is one limitation slider - 0.0 to 33.6mph (54km/h)
And the Max Fligth Speed - 0.0 to 33.6mph (54km/h)
Per each waypoint settings, you can adjust the speed there too.
However, the maximum speed here will be determined by the Max Speed in the Mission Hub settings.
so the slider can only show 0.0 to max speed selected.
 
That is correct.
My logs recorded the actual 33.6mph max for Litchi.

There are two speed settings.
On the Mission Hub app, under settings there is one limitation slider - 0.0 to 33.6mph (54km/h)
And the Max Fligth Speed - 0.0 to 33.6mph (54km/h)
Per each waypoint settings, you can adjust the speed there too.
However, the maximum speed here will be determined by the Max Speed in the Mission Hub settings.
so the slider can only show 0.0 to max speed selected.

Yes, I have both the cruise speed and max speed set to 33.6....and I have each waypoint set at cruise....but I am still at 20 max. I turned off the obstacle sensors thinking that would help, but no. Im sure it is simple, but missing something somewhere.....
 
Yes, I have both the cruise speed and max speed set to 33.6....and I have each waypoint set at cruise....but I am still at 20 max. I turned off the obstacle sensors thinking that would help, but no. Im sure it is simple, but missing something somewhere.....

You might want to run that by Litchi support.
Obstacle avoidance should not have to be turned off to achieve this.
They will know what is going on.
 
If you get an answer from Litchi, please post it here so the rest of us can know what is happening. When I fly a Litchi mission my Spark seems to be in Sports Mode on steroids. It knows where it wants to go and doesn't waste a moment getting to the goal.
 
If you get an answer from Litchi, please post it here so the rest of us can know what is happening. When I fly a Litchi mission my Spark seems to be in Sports Mode on steroids. It knows where it wants to go and doesn't waste a moment getting to the goal.

I'm sorry AirCam, you have the mission plan and the flight logs.
Just send them an email to [email protected]
Describe what is going on and attach your mission file and logs demonstrating the restricted speeds.
 
I don't have any problem with slow speeds, I am just curious as to why Tafische is having a problem and want to be sure I don't do whatever he is doing.
 
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I had already asked Litchi beta support about it and they didnt know. Said it was Firmware controlled and not an app issue. I have some time tonight hopefully to do some playing.

@AirCam - I would not call it slow speeds, it zips pretty well but just not as fast as when in manual. My concern is that the mission estimated time is off since it is calculated on a faster speed. I have manually set my max at 20 to ensure I have no issue.

I have 4 batteries and a few missions ready to go so we will get this figured out.
 
I had already asked Litchi beta support about it and they didnt know. Said it was Firmware controlled and not an app issue. I have some time tonight hopefully to do some playing.

@AirCam - I would not call it slow speeds, it zips pretty well but just not as fast as when in manual. My concern is that the mission estimated time is off since it is calculated on a faster speed. I have manually set my max at 20 to ensure I have no issue.

I have 4 batteries and a few missions ready to go so we will get this figured out.

Make sure to run your logs through an analyzer to see your top speeds.
 
Ok - so I did several test flights and I think I see what is happening.

Avg Wind speed: 11.3 Mph
Avg Direction : 32o

You will see in the video I did 5 waypoints. First flight was autopilot, second was hand flown. Speeds are below:

Waypoint 1-2. 15 auto / 26 manual
Waypoint 2-3. 25 auto / 28 manual
Waypoint 3-4. 14 auto / 27 manual
Waypoint 4-5. 28 auto / 28 manual

If you look at the amperage usage, during the auto flight, it was nominal and never went out of green. When flying manual, it had periods of high power pull.

So it raises the questions - is the power being throttled to avoid high power usage? If so, is there a way to get around this?

What are your all's thoughts?




 
Ok - so I did several test flights and I think I see what is happening.

Avg Wind speed: 11.3 Mph
Avg Direction : 32o

You will see in the video I did 5 waypoints. First flight was autopilot, second was hand flown. Speeds are below:

Waypoint 1-2. 15 auto / 26 manual
Waypoint 2-3. 25 auto / 28 manual
Waypoint 3-4. 14 auto / 27 manual
Waypoint 4-5. 28 auto / 28 manual

If you look at the amperage usage, during the auto flight, it was nominal and never went out of green. When flying manual, it had periods of high power pull.

So it raises the questions - is the power being throttled to avoid high power usage? If so, is there a way to get around this?

What are your all's thoughts?





no no no...Waypoint missions are different than Orbit.

Start your mission from the ground in P mode and try again.
press the triangular "play button" to start the propellers and the mission.

That is the only difference I see from your running of a mission compared to mine.
 
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What have you entered for the default Cruising Speed in VLM Settings? What speeds are you setting at each way point? Is it possible that you have set a slow Cruising Speed and have manual speed entries on some of the other way points? You have an actual speed of 24MPH on the 2 to 3 leg but about 10MPH slower on the rest. Without seeing your mission plan it is pretty difficult to understand the speed differences on the legs of the mission.
 
no no no...Waypoint missions are different than Orbit.

Start your mission from the ground in P mode and try again.
press the triangular "play button" to start the propellers and the mission.

That is the only difference I see from your running of a mission compared to mine.

Did I say Orbit somewhere? If I did, my mistake.

I have tried taking off in multiple different ways and just went a did a test flight using your method with the same results.

What it appears to me is that the Spark is being current limited. When flying into the wind, it goes slower. When flying with the wind, you can see it slowly build up speed.

If this is the case, I can sort of understand why DJI does this to minimize loss of aircraft risk. My guess is that it probably can go the same distance but at a slower pace which is using less battery to make it possible.
 
What have you entered for the default Cruising Speed in VLM Settings? What speeds are you setting at each way point? Is it possible that you have set a slow Cruising Speed and have manual speed entries on some of the other way points? You have an actual speed of 24MPH on the 2 to 3 leg but about 10MPH slower on the rest. Without seeing your mission plan it is pretty difficult to understand the speed differences on the legs of the mission.

Cruise and Max are slid all the way over to max. Waypoints are at cruise. You can see it at the end of the video.

Edit - here are the screenshots


 
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