I am developing an unpowered paraglider system that will return the payload from a weather balloon to one of a few clear/open landing areas. The idea is that depending on where the balloon bursts the Pixhawk will autonomously choose the best landing point (based on a pre-calculated prediction from software before ascent). There are two main problems: the parafoil lacks any controls other than ailerons, and path planning to avoid being carried away by the wind.
Ideally, the Pixhawk would know to point itself into the wind, reducing ground speed to burn off excess altitude with minimal change in horizontal travel (basically keep heading into wind and GPS track towards target). As I understand it, the autopilot would instead try to head directly to the landing point and loiter down to it, pitching down to fight any overpowering wind. This is a problem since there is no elevator and the parafoil would get carried away if the wind speed is greater than its cruise airspeed.
Are there any options within Mission Planner to achieve this result? I assume I will need to edit the firmware to implement this new model, but I am unsure of where to start in the code.
I’m new to Ardupilot so any help is greatly appreciated!
Replies
NASA launches rockets, those cost significant amounts of money and the legal framework keeps a small army of legal experts busy.
DIY rocket enthusiasts also launch rockets, the simplest one can be as cheap as a plastic bottle with water and compressed air at a cost significantly lower than NASA. DIY enthusiasts also launch all kinds of junk into the stratosphere using high altitude balloons, you tube is kind of full of those but this is one of the most delicious ones:
https://www.youtube.com/watch?v=c8W-auqg024
I don't know how much it cost but I suspect it must have been within the budget of the average hobbyist.
I also suspect that this is a site that would attract the average hobbyist and that the big buck researchers with the expensive equipment have other considerations and design resources than this site.
Given that the OP's profile seems to indicate he is a Master's student, I suspect he doesn't fall into the big buck, tried and tested, army of lawyers social class. I could, of course, be terribly wrong.
once again,
I am always on topic
read below and say that you are sorry
If you try to say, that Colin Gibson is not on topic, so I have nothing to say.
If you have previous knowledge and experience in launching weather balloons, building weather balloon's payload rescue systems, just share your knowledge.
In public discussions we must meet public standards.
Launching weather balloons is not $10, $100 activity.
You need to get licence, buy licence, your activity is controlled by the public administration, by FAA and 10 more agencies.
Launching weather balloons is not a hobby.
This is a science, research and strategic activity, closed to the peers.
Every my assumption is correct and can be easily verified, contacting FAA, Weather Administration, UN agencies or any university involved in weather research and study.
You are free to call Climate VIPs, meeting at UN to discuss #ClimateAction
"system that will return the payload from a weather balloon
"
Parafoil Return to Point Descent Vehicle
I am developing an unpowered paraglider system that will return the payload from a weather balloon to one of a few clear/open landing areas.
RM Aviation said:
No Darius you are not on topic, as usual you hijack a thread and make wrongful assumptions about the discussion at hand and plain errors in understanding the salient points.
You said:
"The OP asked about getting a parafoil to return from a balloon, presumably bursting at high altitude. There was no mention of payload price. The meteo community are using tried and tested methods because their equipment is expensive but that is their problem
Parafoil Return to Point Descent Vehicle
"I am developing an unpowered paraglider system that will return the payload from a weather balloon to one of a few clear/open landing areas
If you claim we should not discuss the rescue of payload coming with weather balloon, just say it to CG
Andreas Gazis said:
you said: " I do not understand where the assumption for super expensive payload comes from.
You are free to contact NASA, NOAA, any UN agency for details on weather balloon projects and on cost estimates
If your project is small and payload worth $100 , you risk nothing if payload and balloon are lost, since data can be, in theory, radio live transferred to the ground station.
If you represent a university, climate study agency, meteo office, your projects are valued at M$T, so payload rescue matters and
rescue parachute is certified solution in operation.
You are free to publish open ideas and test other options, other solutions, at your own risk.
I wish you luck
Andreas Gazis said:
You said:
" spiral dive is a well tried and tested manoeuvre in the sport
exactly
weather balloon has nothing to do with any sport
weather baloon is not human controlled apparatus
But you are free to test and show us results of your tests, applying spiral dive rescue procedure to weather balloon when burst.
Watching carefully the video above you can easily see yourself that target landing failure rate by master sportsmen is high and risk is not contained.
I am always on topic: WEATHER BALLOON > RESCUE LANDING
RM Aviation said:
@ d j: Sorry, I do not understand where the assumption for super expensive payload comes from. This site is DIY drones, we discuss anything that is remotely capable of autonomous movement.
The OP asked about getting a parafoil to return from a balloon, presumably bursting at high altitude. There was no mention of payload price. The meteo community are using tried and tested methods because their equipment is expensive but that is their problem, this is a forum on DIY vehicles and these push the boundaries of what is currently available. A few years ago, we didn't have multirotors. Now they are fashionable and development is feverish. Before multis, we had airplanes and then multis became super fashionable and overtook them. Boats, sailboats and subs are possible but not so mainstream either. The focus of development is not necessarily dictated by what is possible but includes many factors.
Regarding the videos, the pilots ending up in the water are NOT failing. They are concluding their acro routine with gusto, over a lake, as part of an acro competition. A lot of them end up in the lake, irrespective of whether they decide to do a ground spiral or not (check out how small the landing platform is, they are flying small surface area, heavily loaded wings designed for extreme manoeuvrability). Incidentally the ground spiral is discouraged because of the high risk of the wing snagging on something on the ground, not so much of a problem over water but if you go all the way and touch a wingtip to the surface you are really asking for refreshing dip. What I am trying to demonstrate is that the spiral exit is VERY controllable, you are talking about a manoeuvre that can reach descent rates of 20 m/s (plenty fast to crunch your bones on impact) and yet competent pilots exit it with a margin of error of a couple of metres. Our use case here would be fine with a margin of error of a few hundred metres!
As to how easily an unmanned platform can perform it, have a look here at an RC paramotor going bananas:
https://www.youtube.com/watch?v=HTNVsTEmv70
The RC pilot is pulling off a complete acro routine, far beyond a simple spiral dive.
Darius you are so wrong.....again. Deaths in paragliding have nothing to do with the discussion at hand and do not support your point in any reasonable manner. The spiral dive is a well tried and tested manoeuvre in the sport and is taught to all students, it's safe and controllable when used correctly and is highly effective in loosing height quickly whilst maintaing control. The evidence is available easily for anyone who cares to look for it. Try staying on topic and talking within your knowledge level.
d j said:
follow up
did you count failed landings in your video (jumping into water) ?
https://www.youtube.com/watch?v=nH__8UbK1S8
I meant this reply have been deleted
Rescue parachute is pretested, verified and certified technique to save playload in case of balloon's burst.
If you launch $100T+ weather balloons project you have to get insured against any risk ( all risk must be contained).
In case of paragliding, I recall my friend Alain from France, who have joined paragliding 40+ years ago and in that early days of paragliding, half of a paragliding team of his friends already died in crashes.
Humans can control a dive, sensing more valuable data and processing the risk rescue as a number of interactive procedures and activities, actions.
I remember Pixhawk drones crashing frequently due to bug in software and in hardware, analyzing black boxes.
Watching expert paragliders on video is not a real life.
Rescue parachute is a reliable technology, what you try to implement is high risk electronics + high risk mechanics, which can easily fail at high altitude.
You need to invest your own money into your I Can Do It Project and take all the risks on yourself.
It may take years for such project to succeed to get weather balloon + payload insured, get all required certificates.
If your payload is worth $100 you risk nothing
If your payload is worth $100T ( cameras, spectrometers, radiation sensors, computers ..) you risk everything
https://www.basicairdata.eu/knowledge-center/design/introduction-to...
"Descending Balloon
At the balloon bursts, the probe will initiate to fall back to Earth. To avoid mushing of the payload the recovery parachute should be correctly sized. Reusing ascending equations and replacing the parachute coefficient of drag
instead of the balloon
we get the expression of vertical descending speed.
(4)![Rendered by QuickLaTeX.com \begin{equation*} W_d=\sqrt{{2m_t} \over {C_{dd}A_d\rho}} \end{equation*}](https://www.basicairdata.eu/wp-content/ql-cache/quicklatex.com-c7a70c4c949eab56857da1269fda80e3_l3.svg)
Where
is the area of the parachute. Equation neglects the contribute of the payload drag, likely we will overestimate the descending speed.
Check your local regulations