Hi,

Currently if we want to use waypoints so that they follow the contour of a hill or mountain downward while sitting at the top (set as our home point) we cannot as we need the ability to use negative altitudes (versus the home point). The minimum altitude for waypoints is 0m. In other words 0m from the top of the mountain where we are sitting (and which is set as our home point).

I know, I could change the home point to being the bottom of the hill while I am sitting at the top and use the waypoints with positive altitudes but having the ability to use negative altitudes versus the HP would be a nice ability to have.

If my drone has a problem and does an RTH to the bottom of the hill while I am at the top then I could envision some troubles. I know I could set it to hover if there are problems and then try to change the HP back to the top of the hill where I am but it is once again extra complications.

Until drones are able to calculate the AGL (if ever) having a bit of extra flexibility would be nice. Negative altitudes in C or N mode would not hit the ground anyway (theoretically, assuming the sensors work).

Thanks.

A solution might be to create a mission by recording waypoints in a real flight. Then the height will be the one at which the drone is at the moment the point is fixed.https://forum.dji.com/forum.php? ... 005&pid=3241857

Serg SSA Posted at 2-7 02:34
A solution might be to create a mission by recording waypoints in a real flight. Then the height will be the one at which the drone is at the moment the point is fixed.

Good idea.

I was only thinking about a pre-flight waypoint mission prepared from the comfort of home with a map.

So the actual flight mission would record negative altitudes while the home-prepared mission would not? Interesting.

Pareidolia Posted at 2-7 02:37
Good idea.

I was only thinking about a pre-flight waypoint mission prepared from the comfort of home with a map.

You could try to use https://www.waypointmap.com which allows for the entry of a negative height at least. Not sure if the drone will follow that, though. If you have created a waypoint mission, you can follow the tutorial backwards and import it to the site to alter the saved height.

Be aware that DJI uses Bezier curves in ALL planes, pitch, roll and elevator. You may find your drone trying to crash into the ground.

Waypoint is way too restrictive, as are many of the automatic capture modes, but that does not have to be the case.  For example, Waypoint missions should allow the pilot to alter speed, gimbal tilt, etc. during flight, irrespective of the saved settings.  Making such changes in flight may increase battery drain and prevent the mission from completing, but that can happen anyway.  The only un-alterable settings should be the Waypoint locations (and the 3D path between each) with allowance for negative-altitude waypoints.

Mobilehomer Posted at 2-7 07:19
Be aware that DJI uses Bezier curves in ALL planes, pitch, roll and elevator. You may find your drone trying to crash into the ground.

But that can happen even with regular missions, when you drop altitude between one Waypoint and the next.  The user has to assume the risk in all cases.

Frank071 Posted at 2-7 04:42
You could try to use https://www.waypointmap.com which allows for the entry of a negative height at least. Not sure if the drone will follow that, though. If you have created a waypoint mission, you can follow the tutorial backwards and import it to the site to alter the saved height.

Interesting. I was not aware of this tool. Thanks for letting me know.

Mobilehomer Posted at 2-7 07:19
Be aware that DJI uses Bezier curves in ALL planes, pitch, roll and elevator. You may find your drone trying to crash into the ground.

oh wow. I started reading up on this. I was not aware of the issue. I am guessing the sensors (assuming in C or N mode) would still stop you from a major disaster (assuming no thin undetected branches or similar) with OA. Still, it is not very reassuring.

It almost feels like this could be the reason DJI is so careful about its drones dropping lower in altitude. This in turn leads to the drone refusing to drop lower than the RTH point's latitude when tracking a skier going down a slope for example.

djiuser_fl0AG9OqVP1T Posted at 2-7 12:45
Waypoint is way too restrictive, as are many of the automatic capture modes, but that does not have to be the case.  For example, Waypoint missions should allow the pilot to alter speed, gimbal tilt, etc. during flight, irrespective of the saved settings.  Making such changes in flight may increase battery drain and prevent the mission from completing, but that can happen anyway.  The only un-alterable settings should be the Waypoint locations (and the 3D path between each) with allowance for negative-altitude waypoints.

I agree, more flexibility with WPs would be nice to have. It is a nice tool but maybe they want to go the extra mile in terms of testing before pushing changes that allow for more flexibility. I can see how negative altitudes, taking into account Bezier curves and other issues could confuse many people who are not necessarily reading these forums.

djiuser_fl0AG9OqVP1T Posted at 2-7 12:51
But that can happen even with regular missions, when you drop altitude between one Waypoint and the next.  The user has to assume the risk in all cases.

Good to know and yet another reason to think twice before using the S mode.

Dirty Bird Posted at 2-7 14:42
You can already do this.  After creating a mission select a waypoint, then set Heading, Gimbal Tilt, & Zoom to "Manual".  Next select "Apply To All".  When launched the drone will fly the waypoint route at the set speed(s) while allowing you to control yaw, tilt, & zoom manually with the controls.  There is no Manual setting for mission speed so I am uncertain if forward/back on the right stick will speed up or down?  Otherwise see if it allows you to set the global speed to 0 at which point forward stick may allow you to control speed.  You will have to try it with a test mission.

A lot of good ideas in this post. I did see the manual abilities you mentioned.

Otherwise, if you want to focus on a certain point while moving along the waypoints, you can create POIs, link them to your WPs and then the gimbal will automatically adjust its tilt to point where you want to focus your camera. You will not even have to intervene manually.

Dirty Bird Posted at 2-7 14:42
You can already do this.  After creating a mission select a waypoint, then set Heading, Gimbal Tilt, & Zoom to "Manual".  Next select "Apply To All".  When launched the drone will fly the waypoint route at the set speed(s) while allowing you to control yaw, tilt, & zoom manually with the controls.  There is no Manual setting for mission speed so I am uncertain if forward/back on the right stick will speed up or down?  Otherwise see if it allows you to set the global speed to 0 at which point forward stick may allow you to control speed.  You will have to try it with a test mission.

Thanks.  Just read in the manual (pg. 44, section 5b) that the stick *can* be used to change flight speed.  I wasn't aware of this, and did not want to risk aborting the mission by touching the controls.  Anyway, that at least makes manual speed change possible, regardless of what it was set at when uploading the mission.

What I would like is for all settings (including heading, camera tilt and zoom) to allow manual over-ride during flight.  Even for POI facing waypoints, the camera angle can be off (for instance, when the POI's real altitude is negative), hence manual control is desirable.  Once the sticks are released, the drone can return to the original settings.