Don't crash your Mavic 3 with Waypoints missions

[Meta4]

Because, to me, you are saying all DJI drone altitudes are determined by barometric pressure. This would mean, they are absolute, and not relative. Then it wouldn't matter what the altitude of your starting point was.

DJI heights are all measured by a barometric sensor and gives a height that's zeroed at startup.

DJI drones do not use GPS for height measurement.
If GPS was used for heights, it would be an absolute height and it would be less accurate.

 

[JoelP]

Your drone uses the barometric sensor for altitude, whether you are flying with Litchi or a DJI app.
For years Litchi used waypoint heights relative to startup location.
Later on they offered a height above ground option, but nothing that used GPS for height.

The barometric sensor gives more accurate height readings than GPS does.

Thanks for that correction!

 

[Robert Prior]

When you record a waypoint mission, the waypoint heights are *relative* to your takeoff spot.

Thanks. I didn't know that. Very useful information.

 

[TwoSticks]

We could use both or at least the drone could potentially make use of both. (not saying does, saying it would be nice if it did) When setting waypoints, it records the height as well as orientation. If you need to change your takeoff point but want to run the mission it would be nice if the drone knew the absolute and was aware enough to adjust to the difference. I need to work with them more, maybe there is a way to correct for the first point then use that as the reference for the rest of the points. Another thing I have been meaning to do is set points and see if it will run backwards for the entire route.

 

[JoelP]

We could use both or at least the drone could potentially make use of both. (not saying does, saying it would be nice if it did) When setting waypoints, it records the height as well as orientation. If you need to change your takeoff point but want to run the mission it would be nice if the drone knew the absolute and was aware enough to adjust to the difference. I need to work with them more, maybe there is a way to correct for the first point then use that as the reference for the rest of the points. Another thing I have been meaning to do is set points and see if it will run backwards for the entire route.

You raise a good question. Could I enter a negative velocity for my global speed? I am guessing no.

 

[RUFFSTUFF]

Does obstacle avoidance even work during waypoints? Almost took out a streetlight yesterday flying one, and it didn't even flinch.

 

[shb]

Does obstacle avoidance even work during waypoints? Almost took out a streetlight yesterday flying one, and it didn't even flinch.

I think i saw on a YouTube video that it does, but it just stopped regardless of your settings.

 

[RUFFSTUFF]

I think i saw on a YouTube video that it does, but it just stopped regardless of your settings.

Mine... Set to bypass... Not so much.

 

[Lasidora]

On my Mavic 2 Pro I always use LItchi and enable the Height Above Ground Level settings so if you start your flight at Home Point at 250ft AGL and it approaches rising ground such as hill etc as long as the waypoints are not to far apart it will gradually start to climb above the home point height to match the 250ft AGL, bear in mind that if you are in a restricted flight zone such as I am, when your drone hits the restricted ceiling height ( for me 500ft ) it will NOT go any higher until it leaves this zone.
Another good reason for DJI to release the SDK so Litchi can use the drone for proper waypoint missions again.

 

[mihaildorian]

Helpful hint for those taking advantage of the Mavic 3's new Waypoints firmware: DJI Fly constantly bugs you with exaggerated warnings we've grown used to ignore, but it doesn't warn you of a glaring danger with waypoints missions. When you record a waypoint mission, the waypoint heights are *relative* to your takeoff spot. If you record a waypoint mission having taken off from one spot, then move to another spot that's at 100 feet lower altitude, take off from there and reload your mission, the Fly app won't warn you that all your waypoints are now 100 feet lower, in absolute terms, than when you recorded the mission (because the relative altitudes stayed the same but they are relative to a different takeoff spot). So the waypoint that you marked back when you were at 800ft from sea level, the drone will now move towards that point while flying at 700ft from sea level.
Combine that with the fact that obstacle sensing doesn't detect fine objects like wires, and branches without foliage, and with the ability to set the drone to Continue on Signal Loss, and you have the recipe for disaster.

I wish DJI would at least warn about taking off at a lower absolute height than the one the waypoints

Helpful hint for those taking advantage of the Mavic 3's new Waypoints firmware: DJI Fly constantly bugs you with exaggerated warnings we've grown used to ignore, but it doesn't warn you of a glaring danger with waypoints missions. When you record a waypoint mission, the waypoint heights are *relative* to your takeoff spot. If you record a waypoint mission having taken off from one spot, then move to another spot that's at 100 feet lower altitude, take off from there and reload your mission, the Fly app won't warn you that all your waypoints are now 100 feet lower, in absolute terms, than when you recorded the mission (because the relative altitudes stayed the same but they are relative to a different takeoff spot). So the waypoint that you marked back when you were at 800ft from sea level, the drone will now move towards that point while flying at 700ft from sea level.
Combine that with the fact that obstacle sensing doesn't detect fine objects like wires, and branches without foliage, and with the ability to set the drone to Continue on Signal Loss, and you have the recipe for disaster.

I wish DJI would at least warn about taking off at a lower absolute height than the one the waypoints were recorded.

Litchi use "Online Elevation",in the future dji could introduce this.

 

[Jeff A]

I don’t recall this being an issue with Litchi likely because Litchi missions were entirely based upon GPS altitude and position. That said, I nearly crashed with a Litchi mission when flying a mission created a couple of years before. A tree had added enough height to clip my drone where it had cleared it before.

I have flown many Litchi Missions and all of the altitudes in the mission are based on the altitude on take off. From what I'm reading, the new Waypoints from DJI are the same. And yes, trees can ruin your day.

 

[Meta4]

I have flown many Litchi Missions and all of the altitudes in the mission are based on the altitude on take off. From what I'm reading, the new Waypoints from DJI are the same. And yes, trees can ruin your day.

Originally Litchi waypoint altitudes were all above launch point, but later Litchi also gave an option to set them above (approximate) ground level

 

[Cosmo0g]

I can't save waypoint missions. When I click the little white symbol to do so, it brings up the history page, but there's no option to save. If I click on the waypoint symbol on the left of the screen, I can exit without saving, but if I click save and then exit, it does nothing.

 

[PinkNFurry]

I can't save waypoint missions. When I click the little white symbol to do so, it brings up the history page, but there's no option to save. If I click on the waypoint symbol on the left of the screen, I can exit without saving, but if I click save and then exit, it does nothing.

The save button is on the right side in the history page. Hope this helps.

 

[Cosmo0g]

The save button is on the right side in the history page. Hope this helps.

View attachment 159365

My history page is blank. I set a couple of waypoints, fly the mission, then try to save it with no luck. I tap the white icon that brings up the history page and it is blank and with no option to save. I also try tapping the waypoint icon on the left of the screen. I tap save and close and nothing happens. I can only close without saving or cancel. I'm using a RC Pro with a newly formatted sd card in it. I've also tried with no sd card in it..

Edit: it finally started working. I updated to Fly app 1.9.1 and it still didn't work. While the bird was still in the air, I just clicked through every setting including the camera controls on the bottom right of the screen (didn't change anything). Then, all of a sudden it started working correctly.

 

[mavsam]

Does obstacle avoidance even work during waypoints? Almost took out a streetlight yesterday flying one, and it didn't even flinch.

Mavic 3 Obstacle Avoidance does work in Waypoints missions (unless you disable Obstacle Avoidance, of course), I tested it. Do remember that obstacle avoidance is quite imperfect, so don't rely on it as a primary defense.
However, at least when the mission is set to Continue on Signal Loss, regardless of the Bypass or Brake setting, when it detects an obstacle it initiates RTH if flying without RC signal, and it simply stops in place if flying while connected to the RC.

 

[mavsam]

While I love the ability to run waypoints mission set to Continue on Signal Loss, I settled on this safety rule: The first time of the day that I fly a specific mission, and after any waypoint changes, and after a change of takeoff spot, I must run the mission facing forward (not sideways) while looking at the screen, and with RTH on Signal Loss at least one time, and if that goes well I can go back to running it on Continue on Signal Loss or running it facing sideways/backwards.

 

[Brojon]

I don’t recall this being an issue with Litchi likely because Litchi missions were entirely based upon GPS altitude and position. That said, I nearly crashed with a Litchi mission when flying a mission created a couple of years before. A tree had added enough height to clip my drone where it had cleared it before.

Actually they don't near as I remember. That's why Namora had to add a checkbox to VLM that would adjust each waypoint to teh actual height above ground at that point.
One of the best features IMHO as I've almost crashed into things with Litchi missions and later figured it was the elevation change.

 

[MavicMover]

So with DJI waypoints on the Mavic 3, if I set my altitude to 300 feet, and there is a mountain in the path that is much higher then 300 feet, will it climb in altitude as the terrain climbs? or do I need to put waypoints where the mountain is and adjust each height level?

 

[JoelP]

While it was not with waypoints I flew my Mavic 3 toward a hill. When the elevation dropped to the point that it would have collided with the ground the collision avoidance was activated and it climbed at that height up the rest of the hill. If collision avoidance is active for waypoints it would seem that it would do the same thing, climbing the hill within in the collision avoidance distance. That said, I have not yet tested this.