Litchi speed limit with Spark

Raoul · May 25, 2019

Hello all,
I'm doing my first Litchi Waypoints tests and I am fully satisfied about it. The only thing I could not overcome, however, is the speed limit. Whatever the speed I set as Settings param or as Waypoint param my Spark never exceeds 20-25 Kmh. Is it necessary to set the Sport mode on RC to reach at least 35-40 kmh ? In my tests I have always used POI, could this be to limit its speed?
Thanks in advance.

Haggi · May 26, 2019

I've done a lot of litchi missions.
Example:
You set cruise speed to maybe 20 kmh and max speed to 50 kmh.
It will then do the mission in 20, but speed can be changed until max speed setting with your rc stick.
BUT, in every curved turns it will slow down, sometimes alot. It will only gain high speed in straight lines.
In other words, "orbit-like" missions around poi's will not reach high cruising speed.
Any speed change at waypoints requires solid RC-AC connection.

Raoul · May 27, 2019

Hello Haggi,

thank you for reply. It's raining now and I can't do any more tests, but I remember that even with long straight lines in waypoint mode the speed has never exceeded 25 Kmh. As you say, it is also probable that it depends on the POI settings, which force the Spark to rotate on itself and therefore to fly in a strange way. As soon as I can, I try to set Heading Mode to "Auto (TNW)" and set a long distance between two waypoints. As soon as I have done it, I will let you know the result.
Thank you

Northwood Mediaworks · May 27, 2019

I am interested in this also. I dont understand why in a straight line you would have to push the stick to get max speed... a safety feature? Do you have to continue holding it to get 50kph? Or perhaps I dont understand what Haggi is explaining. Also, what happens when the Spark approaches the next waypoint when there are no curved turns, does it slow down way in advance or stop abruptly before turning?

Northwood Mediaworks · May 27, 2019

Haggi said:
I've done a lot of litchi missions.
Example:
You set cruise speed to maybe 20 kmh and max speed to 50 kmh.
It will then do the mission in 20, but speed can be changed until max speed setting with your rc stick.
BUT, in every curved turns it will slow down, sometimes alot. It will only gain high speed in straight lines.
In other words, "orbit-like" missions around poi's will not reach high cruising speed.
Any speed change at waypoints requires solid RC-AC connection.

I did not understand you regarding the stick.... does this have to be manually whilst in flight?

Haggi · May 28, 2019

My understanding of a Litchi Waypoint Mission:
You can make a mission with poi's and have the drone/camera automatically point towards this/these. Fine, thats one of the main features of Litchi.
Another main feature is it will complete your mission even if connection is lost! Behaviour if/when connection is lost can be configured in app.
You can even set custom heading or even initial heading for those spesial cases/shots.

Do we have more options?
Yes, you can set actions on waypoints!
Speed, gimbal pitch, take photo, start/stop movie etc..
Important notice about actions is if you set any speed change or gimbal pitch change on your waypoints, you need a solid RC-AC connection! I always plan missions with actions on wp's to be within range of RC.
When uploading you mission to your drone, it will not contain everything about your mission. Some stuff, like actions, is controlled by your app through RC-AC connection.
Same with speed, cruising speed is your initial/programmed mission speed.
It can be changed by your RC stick, and new mission speed will be set. If you have no speed set at your wp's, this will be your speed the rest of the mission.
Manual clearly state that if connection is lost, mission will be completed with the speed the drone had when connection was lost.

Okay, waypoints..
They can be curved or not.
Regardless, the drone will slow down.
Curved waypoints cannot have actions set, because drone clearly misses the actual waypoint. But thats wanted behaviour, right? ?
A curved waypoint, by default, is devided into 5 "invisible" wp's.
And that's the reason it slows down during the curved turn..
Most of my missions is done with curved turns, and if cruising speed is set to 30 kmh, it will do the curves in 15-20 kmh. This will also be the speed in the curves if my cruise speed is set to 50 kmh!
By now, you understand that you will not be able to do an orbit mission around that famous lighthouse in 50 kmh!

Still reading?
Do not expect obstacle avoidance to work during your missions. Always plan your missions like it isn't active!
Spark front sensor limit is 5 meters and speed must be max around 10 kmh..
Most missions will not point the front face of the drone in the flight heading direction.. that's why we make missions, right?

Fly safe and make your missions well cleared of any obstacles.. and ground!

Northwood Mediaworks · May 28, 2019

Thank you Haggi, this helps greatly.

webvan · Jun 19, 2019

Very helpful indeed ! I suppose that if connection is lost and then regained the app will reapply the settings starting at that point.

I'm finding Litchi missions to be great but with the two-axis gimbal I see a lot of left-right "stuttering" with the Focus POI feature. I suppose the results would be a lot better with a Mavic Pro or an Air...Maybe it can be somewhat stabilized in post.