Rc signal lost behaviour
Autopilot is still my go to flight controller, also written by Jim.
I don’t understand why the DJI on board mission allowing continue mission on RC signal lost is a big step backwards in terms of user interface. When a user selects continue the mission on RC signal lost, Autopilot simply moves POI’s to the nearest waypoint and has a mission default speed and height. The operator can assign heights and POI’s to waypoints. Dronelink draws a path with no waypoints or mission metrics marked, it is a guess at what speed the drone will fly which makes it difficult to estimate duration and therefore battery life. Autopilot onboard mission also supported bezzier curves, not a series of straight segments with configurable corner radius. The design and virtual previews of Dronelink is fantastic. A pilot has far more predictability, control metric visibility of a signal lost continue mission with Autopilot than Dronelink. Why don’t you reuse the Autopilot code when using the DJI onboard flight controller?
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This article explains the pros and cons of virtual stick and onboard waypoints. TLDR: onboard waypoints have a very limited feature set and going from the Dronelink mission format (virtual stick) to onboard waypoints (DJI) is like mapping a 3D object into 2D space - you lose something when you drop a dimension. As for it being a step backways from Autopilot, I can’t really agree. In fact, in many ways it is a step forward, such as automatically converting multiple components into multiple DJI waypoint missions behind the scenes, and then automatically uploading each one successively.
Dronelink does the same thing.
If you click on the component, it shows the speed. You can also click on each waypoint and see the speed. Better yet, you can click the estimate, or mission preview and see exactly what is going to happen after you convert.
Dronelink supports bezier curves during conversion.
https://support.dronelink.com/hc/en-us/community/posts/4404662645267/comments/4404776641939
Thanks for the reply, drone link is great for missions with RC signal, unfortunately most of my missions loose RC for a portion of the journey. I will experiment more with the conversion, I agree multiple mission uploads is better. It would be good to tap on the path and have estimated time displayed. Autopilot dashboard displayed the waypoints which if taped displayed elapsed time. This enables the pilot to estimate when Ric signal will return.
to be able to select multiple waypoints and edit the speed and height of the selected points would save time.
how is the speed calculated for each DJI waypoint, a maximum speed of 54km in the original mission results in 7 to 20km/h in the early weight points. Bézier curves are on the original but only see options for normal and curved on the DJI mission with option to set the curve radius.
not dismissing the mission when RC is lost would better reflect what is really happening, the mission is continuing that’s why it is converted onboard. The option to dismiss should pop up when the drone arrives at the final waypoint. Autopilot also started an elapsed time when the mission started, this avoids having to use a phone stop watch.
thanks once again, I will investigate the DJI conversion further.
regards
The Dronelink way of doing this is to run a mission preview, drag the timeline slider to the desired point, and check the time elapsed:
This is already possible:
You original mission plan has settings about how fast it thinks the drone can accelerate and decelerate (both at the start and end of the mission, and around tight corners):
When Dronelink converts your mission, it samples the flight path and places waypoints often enough to approximate the original bezier curve, and also sets the speed of those waypoints to whatever the speed actually was during the original acceleration curve. For example here is a Dronelink (virtual stick mission) with bezier curves:
Here is a converted DJI waypoints mission with the sampled waypoints approximating the curves and setting an increasing speed at each one:
Not sure I understand what you mean by this one. When the drone disconnects, the mission stays loaded, and as soon as it reconnects it updates the status of the mission card to reflect what is happening onboard.
thanks for the detailed response, will put it to the test.
When Ric signal was lost a pop up was displayed with dismiss. I hit dismiss and path remained on the display when RC returned the drone tracked on the path until done as expected. On one occasion the path disappeared, I am not sure what I did, I switched screens (on an iPad) and on return the path had disappeared. Will try and be more precise on actions performed to clear the path before mission complete.
Autopilot supports Bézier curves with a sparse number of waypoints (not approximated with straight segments) on continue mission on rc lost.
Autopilot did not support bezier curves with LCMC enabled (I should know, I wrote the code). The issue is the underlying DJI Waypoints API only supports straight lines with rounded corners, which is always what the Dronelink DJI Waypoint component type supports as it is built on the same API.
Thanks Jim I believe you.
but you should also know when you switched to continue mission 100 extra waypoints did not appear.
All I know is under Autopilot I would prepare a mission and the mission planner drew curves (Bézier or not), when I switched to continue when Rc lost, the poi’s would move to a waypoint and the drone would fly that path to the letter.
In Autopilot I have learnt to control speed ( in Rc blind spots) by placing waypoints close together and changing altitude up, down, up, down by a few meters.
The point is it was simple and intuitive. I believe your passion and technical know how and skill for developing drone flight controllers is unsurpassed.
I am a 70 year old expired electrical engineer that has been developing software for control systems before the Popular mechanics Altair computer in 1975 that made Bill Gates famous ( in the end). I speak from experience with Autopilot and (limited experience) Dronelink, you speak from knowing how they truely work with a passion.
We appreciate the time and effort you put into to respond to the users.
Have play with Apple Store iTalkAussie which I wrote about 10 years ago because I was so in ore with todays portable computing platforms.
I was a systems programmer on ibm 370’s (does not have a stack pointer, subroutines used jump and store so no recursion) for a while in the 70’s.
That's because Autopilot automatically turned on straight segments with rounded corners when you turned on LCMC. Dronelink goes a step further adding the extra waypoints so that the converted mission matches the original flight path as closely as possible (essentially creating a poor man's bezier curves implementation where the DJI SDK lacks the option).
Thanks Jim, I now agree that Dronelink DJI onboard mission is superior to Autopilot, the ability to set speed in Rc blind spots , multi edit waypoints, multiple paths, user controlled curve approximation etc.
I have done a similar thing with Autocad curved designs writing macros to convert the curves to a large number of very small line segments suitable to control an NC laser cutter.
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