Confused by Headings

Please don’t say “read the Litchi manual.” I have done so, several times, and still have an issue I can’t resolve. I created a simple waypoint mission in Mission Hub to record the surface of a parking lot. The Gimbal tilt needs to be -70 at all times. I want the drone to fly from WP1 to WP2 with the camera pointed strictly in the direction of travel until it arrives at WP2. At WP2 I want the drone to turn toward and fly to WP3, again with the camera pointed strictly in the direction of travel. When it arrives at WP3 I want the drone to turn toward WP4 and continue in the same manner. I have saved a mission using AUTO/TNW in Mission Settings and edited Mission Settings to use CUSTOM and have flown the VLMs for both versions in Google Earth Pro with the same results: Going from WP1 to WP2 and going from WP2 to WP3, the camera did not “track the line” as I had hoped. Instead it “transitioned.” Along the line of WP1 to WP2, the camera swung left as if it was “transitioning” toward WP3. Along the line from WP2 to WP3 the camera swung to the more to the left as if it was transitioning toward WP4. Along the line from WP3 to WP4, it tracked exactly as I hoped.

So, am I misinterpreting the meaning of “next” in Auto/Toward Next Waypoint? When I am at WP1 and want the camera to point TNW, I assumed it would point to WP2. But the behavior I am experiencing makes me think “next” must mean “the waypoint after the current leg of the mission,” hence, along the line WP1-WP2 the camera is already looking and “transitioning” toward WP3. Is that correct?

If you wanted to fly this mission exactly as I have described … as a 3-leg, straight-line, looking straight ahead between waypoints … how would you set it up? AUTO/TNW and CUSTOM both let the camera “transition.” INITIAL doesn’t allow any changes in the WP settings dialog box, and Manual requires stick control, not any automation.

Bethel Litchi

You should NOT use the ‘Custom’ setting for Heading Mode in the Mission Settings. Set it to AUTO (TNW). This will keep the flight going straight toward the next Waypoint, at which point it will rotate toward the next one.

And it does say in the Mission Settings for Waypoint Help:

Choose between “Toward next Waypoint” (“Auto” on iOS) where the aircraft will point toward the next waypoint
Using “Waypoint Defined” (“Custom” on iOS) also means that the aircraft will smoothly transition from one waypoint’s heading to the next.

The heading mode you want to use is “Auto(TNW)”. I’m pretty sure that VLM always assumes that the heading mode is “Custom(WD)” because that is the mode most often used mode. As a result, an “Auto(TNW)” will be flown as expected but will look wrong in VLM.

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Hi Sam, yes, thanks. I guess I wasn’t perfectly clear in explaining what I had done. I originally set up the mission using AUTO/TNW. When I ran the VLM in Google Earth Pro, the camera “transitioned” as I described. So I changed the setting to CUSTOM and saved it as a different mission, ran the VLM in GEPro and saw the same result. See Wes Barris response below. I’m just getting ready to run the missions in Simulator mode in the Litchi app to see which flies with the correct heading.

Thanks, Wes. I’m just getting ready to run the missions in Simulator mode in the Litchi app to see which flies with the correct heading. Will report back.

Just ran the missions in Simulator mode. If the Heading is set to CUSTOM the camera “transitions” in Simulator, just as it did as a VLM. If the Heading is set to AUTO/TNW everything looks right in Simulator but the camera “transitions” in VLM. So, my conclusions are (1) use AUTO/TNW for this type of mission and (2) trust Simulator over VLM/Google Earth Pro if the Mission Setting utilizes CUSTOM Heading. Thank you for that insight, Wes. I learn something new here every time I log in.

Dont you mean 'trust Simulator over VLM if the mission utilizes AUTO/TNW Heading?

Because you had just said …

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Ahhh, yes. Thank you. Tired brain. Simulator shows accurate heading and camera action for both AUTO/TNW and CUSTOM waypoint missions. VLM is accurate for CUSTOM missions, but it is misleading for AUTO/TNW missions. While it follows the flight path accurately, It shows the camera “transitioning” for AUTO/TNW missions, therefore cannot be relied upon to show what the camera will see.

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