guided landing

I know someone here is working on active stabilization system to keep the rocket straight, but what about landing?

I'm not sure how controlling parachute works, but I thought skydivers could control the direction they drift by pulling on something to affect their descent direction, so I'm wondering how complicated would it be to fit a system to where you could remotely control the parachute so that it lands closer to you, and hopefully away from trees?

With our normal parachutes, Circular it would be kind of hard to do such a thing.

Now if we used the same style of parachute that skydivers use, it creates forward motion, they steer by dipping one side lower and turning the chute. So if we used such a Parachute on our rocket we would induce a lot of horizontal movement, but it might be possible to do if you create some sort of rig that extends from the bottom of the risers and can pull down on one side or the other. Thus causing one side to drop and in effect turning the parachute to and forcing it to travel in another direction.

You would need to guide it all the way down, and keep turning it in a circle once you get to your desired landing area or it will drift off. And you would have to contend with a large horizontal velocity upon landing.

I think its possible, and would be neat if you can do it by remote or even automate it to land near the point of origin. Not sure how much drag the parachutes create but it might I do believe it is a lot less than our regular ones so you may need quite a large chute compared to a regular circular one.

Check out my thread, https://www.rocketryforum.com/showthread.php?t=122439 I am working on it. A typical skydiving or parasailing chute is likely to efficient for a rocket and might over fly the rocket on the way down. I have a parachute expert designing me a nasa wing kite for my test rocket and he will be manufacturing them in various sizes for rocketry once my project is done. I have also recently acquired a custom spherachute with reefing rings and will be testing a controlled reefing system in the next few weeks. This system will allow my rocket to use a single chute and descend at a programmed rate up to 200 ft per second until a lower altitude then gradually slow to a nice 15 ft per second.

A GPS-guided parasail chute would be very cool. It might end up being a bit expensive for most projects, but for that strato-buster or big L3 rocket it might be just the ticket.

I'm thinking for a GPS guided chute you could just motor eject and not mess with DD at all. I mean you could just control descent rate with the one main chute and steer it.

Also given how electronics seems to get smaller and smaller, fitting a lot of functionality into a small piece of circuit board is not beyond the realm of possibility. After all, the logic board (motherboard/cpu/etc.) of a smart phone is only 2x the size of a postal stamp! But assuming something like this comes out it could still fit into a 35mm tube, and of course you'd need servos to control it. I'd say about the same complexity as active stabilization system.

One difference would be that you wouldn't need quite the response that you need with an active stabilization system, since you're only moving maybe 40-50 fps. If you sampled only 10x per second you'd still pretty much nail the landing spot... assuming that you can integrate baro altitude into this so you get a more accurate AGL reading than you'd get with just the GPS.

Armadillo Aerospace has been working on this, I remember seeing some other videos a while back and thought they were working on the system for themselves. If I am reading it correct they either sourced it out or just used Wamore Inc. for that technology. My guess is that the price would be prohibitive but I agree that it would be a game changer for our hobby especially for any higher alt launch, if it scaled down.

https://www.gizmag.com/stig-b-armadillo-aerospace-gps-guided-precision-landing/25536/

[video=youtube;UV7zL07Tof8]https://www.youtube.com/watch?v=UV7zL07Tof8&list=UUogDkGI_WtSoVXtbUvRzzjg&index=2[/video], the video just makes me laugh

A video on some of their tests and adjustments

[video=youtube;c55L-6Wo_dQ]https://www.youtube.com/watch?v=c55L-6Wo_dQ[/video]

Most of the larger US military supply airdrops today used GPS guidance. https://en.wikipedia.org/wiki/Joint_Precision_Airdrop_System There is little reason why you can do the same for a rocket recovery system if you understand the required control line motions of a parafoil.

The EagleTree Vector Flight Controller should be capable of doing the navigation however the devil is in the details of the parafoil control configuration. Whether or not you could totally automate the process remains to be shown but you certainly should be able to assist it with a standard R/C radio.

[YOUTUBE]yyBZgBDz0oY[/YOUTUBE]

[YOUTUBE]Ih3joSAjEHA[/YOUTUBE]

https://nsrdec.natick.army.mil/media/print/JPADS_trifold.pdf

https://www.defenseindustrydaily.com/jpads-making-precision-airdrop-a-reality-0678/

Bob

I've been messing with this for a long time. Here's my original build thread Build-Thread-7-cell-parasail-w-RC-control

The principle is the same as any sky diver. You want the forward speed, about 20 mph, so you can move into the wind if you want to and so you have control of the chute. When moving forward, you pull down the back edge on one side of the chute causing it to slow down. That will cause you to turn in that direction.

I've had no issues with the RC part of this and the chute works well. The problem is deploying it.

First is how to pack it. Man rated chutes like this are packed in rectangle, flat, backpacks. This needs to be packed into a tubular bag. It does need to be packed into a bag and have a controlled deployment or you can't be sure it won't tangle.

The first issue is that since this is intended to be deployed by RC control soon after apogee, I don't want the send the nose cone down on it's own separate chute, although treating the nose cone as disposable and discarding it may be the final solution.

This leads to the issue of the chute tangling with the shock cord the nose cone is attached to. That cord goes from the nose cone to the top of the RC module and is intended to allow the nose cone to hang along side the RC module. This hasn't worked today. Sometimes it wraps over the chute and causes one side to collape, other its ended up wrapped around the chute and shrouds and prevent any deployment at all.

I believe I have a method worked out that may work, but it's not a priority right now and is sitting in the build pile.

BTW, the chute wasn't that hard to build. It's just a scaled down version of a man rated chute, or in this case, an upscaled version of a RC Skydiver chute.

If you do pursue this, make sure you do a build thread. I would be very interested in how you ensure successful deployment.

I finally had a chance to fly my kite system at Midwest power XIII, this will be cross posted in some of the other threads on this topic since different people may be subscribed to each. Here is the onboard video from the flight. The cameras are pointed 90 degrees from each other, one is pointed up at the kite to check for tangling and watch the control line activation the other is pointed forward relative to the direction of flight of the kite.

The flight was both a great success and a failure. The primary purpose of the flight was to prove that my unique recovery system could be deployed without tangling and that I would be able to control the parachute. Both of these were extremely successful, the kite opened rapidly without and snags and the control lines were able to turn the kite. I was able to execute several turns through out the course of the flight with no problems. The flight was a failure however because in the switch from smokeless powder to black powder I over sized my charges and the main parachute ejection sheared the pins for my backup chute at apogee. The large backup spherachute, which was only to be deployed in the event of a fouled main, over powered the kite and dragged the whole assembly down range preventing a return to the pad.

I am now in the process of building a new fiberglass rocket to act as a test bed for this recovery system and I have made some significant design improvements to make loading it as simple as possible and to allow for testing of a feature of the kite to "depower" it for faster decent during early stages of the recovery. I am also making every effort to design the next iteration in a way that it can be developed into a kit for 4" and larger rockets. I have no doubt that the new rocket will be flying in early spring and will reliably allow for successful remote controlled recovery.

[video=youtube;uHWgrsvF7VM]https://www.youtube.com/watch?v=uHWgrsvF7VM&feature=youtu.be[/video]