This was a well thought out application challenges/educational video; however, I cannot help to think if you had simply added two rudders behind the motor thrust-line so regardless of the flight mode you had same control inputs. Any thoughts?
This is probably the most cogent explanation I've seen about tailsitter flight dynamics. Breaking down the problems one step at a time, plus not being afraid to show code, makes this super easy to understand. Excited to see your next build!
Seeing each step was fantastic! I'm especially impressed he was willing to fly all of the intermediate steps that he knew were going to fail. It's so easy to just think through these problems and skip to what you assume is the finished solution, but actually testing the physical response of using a binary transition or not changing the forward flight gains really drives the lesson home.
The fact that you give such a good explanation into how and why you did things, makes this video to be into a whole other level. It passes from being an entertainment video to be a super good educational video + still being fun to watch. I'm exited to see the next project.
Yep, I think it's time to breakout the drehmflight board again and play with it some more! You really have made something special here with your software and videos. I appreciate you taking the time to share this stuff with the world
Nice! It's always cool to see people who are able to do physical design/builds, complemented with coding skills to solve both problem domains. Really looking forward to your large, folding design!
fabulous video. i really like the progression: stepping through each problem on the path one at a time, and placing the viewer in the mode of expecting each change to be the last one, but then exposing the remaining issues to address
Nicholas, your videos are great and this one is particularly excellent. That was a great demonstration of engineering synthesis and how to systematically go about solving multiple problems. It was great that you were able to show how the VTOL behaved under the various steps of the design process.
Great technical overview! I purchased Horizon Hobbies Xvert 5 years ago. Great VTOL and performs like your plane for transitions. This plane is a ton of fun to fly and very inexpensive. Keep it up! Love your videos.
I don't recall how I stumbled upon this channel but I'm happy I did. The way you explained all that gibberish was impressive. Keep doing what you're doing!
The only thing your “unimpressive piece of foam” needs to be my dream aircraft is a camera, vtx, and code that pivots the camera mount 90 degrees during flight mode transition. Your next project looks absolutely stunning! I can’t wait to see it! Thanks again for all your hard work and for sharing it with us. 🙏
I suppose a second camera and a PWM-controlled switch would be about the same weight as a servo and linkage, with less mechanical complexity. If the camera switch signal was sent as part of the flight mode transition function, it would make the transition even simpler. Thanks for the video suggestion. 👍
You are brilliant. Everyone wants to see you build a single-seater VTOL machine capable of 1 or 2 hours of flight time, will essential avionics (com, nav, weather), and some safety features (enclosed blades or jet ; crash parachute...) ; plus a pivoting nacelle - that would be THE airborne motorcycle
Flight dynamics and controls is such a challenging problem. So many important details! Great clear walk-thru of the basics leading up to achieving stable transitions. Being able to make reasonably smooth transitions to level flight without airspeed or angle of attack sensors is pretty amazing. The ultimate test would be to fly the tail sitter through a loop, or barrel roll ... involving transitions to hover at various points in the maneuver.
Glad you was able to hear what I was screaming through the screen from the beginning of your video about you need a factor changing the weight of control and two different controllers for diffenent modes. :D
Reminds me of something :) I was planning to try the gradual transition sometime, but using a little simple sin/cos scaling. Seems to me that the relation to gravity magnitude is what matters, and that does not change linearly with pitch angle.
Maybe not gravity... It's true the gravity stays constant but I think the distinction is because regardless of pitch angle, air provides the same control authority from a control surface regardless of the direction that the plane is flying. Air gives the same resistance regardless of whether you fly up or sideways.
That would be awesome....... I have tried a few tail sitters but nothing worked hence the excitement and comment.. Still flying the F35, made a few tweaks to the transition timing so its dialed in and does not dip down when going into FFF..... I have the Nemo set up ready just waiting to assemble the printed parts.. also have another teensy ready to be set up for a small F18...... I was wondering how big a plane you could use this board on as I have a few larger foamies that I want to try it on just for stabilisation.... as for me I just retired 3 months ago and we have been travelling and just relaxing..... if you want to see some of the plane stuff I have been doing since retiring feel free to check out my YTch ... I hope all is well there with you, stay safe and keep up the great work.. BTW I still check in the RCG thread to keep up with what is going on... cheers from downunder @@NicholasRehm
Well that freaked me out. I was across the room listening to the end of the video and I hear (seeming to come from someone in the room) “hey look it’s RCTF” and of course the next thing I hear is Daniel’s voice as a video I had started yesterday auto-played. I was utterly confused for about five seconds. Well done lol
Hey, I know you aren't impressed with your "piece of foam", I am impressed. I've been trying to get a plane working but struggling with the balance because I have older, heavier equipment. Basically, another awesome job! Well done.
The code is very clear and simple and well written. Thanks for making that available, it helps see how all this works. Have you done any more on the spinning 3-wing drone. I love the way it looks in straight flight. You left a teaser at the end of "part3" but I don't see anything since and that was a year ago.
Love how to showed the code and talked about how. Peeps leave out the details so thanks for the info cause I want to do this shit but I ain’t that so any info is awesome!!
Loved the video. I just finished a project using the ESP32-S2. It was a big one. 1.1MB in Flash. I know even the ESP32-S3 doesn't have the power of a Teensy 4 (@600MHz), but does it have the power to run your code decently? Would it be the clock speed (240MHz) that's not fast enough? Was ESP32 available when you wrote your code? Or you just went with the best and biggest horsepower? 6:23 looks yummy! Soon I hope...
Some people have ported the code over to the esp32-s2 and said it runs just fine. The teensy 4 has STUPID compute overhead for this relatively simple code, I just like having the option if I want to load it up with other stuff :)
@@NicholasRehm interesting, also did they use Arduino or ESP-IDF? Also i am not that surprised it runs well on ESP32-s2 since unlike an arduino uno or RP2040 it has a floating point math unit and for the type of math that you are useing it is a great gain in speed. Also remember NOT to use core0 when useing the WIFI/BT since it may lag important code running on it . The tensey 4 was a huge overkill to begin with (unless you wanted to ad video/photo to SD)
This is an awesome project and walkthru for the "hover to forward" flight problem, I followed your thoughts the whole way and it is so satisfying! One thing I'm not sure about is at 8:20, did you set the fade transition time on a fixed timer, or is it something else that's controlling/adjusting how fast or slow the fade phase should be? Thanks for answering my question and for creating such awesome content, keep up the amazing work!
It's on a fixed "timer"--in reality it's just rate-limiting how much that variable can increment with each flight controller loop if that makes sense. I tune that increment size which directly corresponds to total time from 0 --> 1
Thanks for the arduino version added to the RCGroups page... now to sort the wiring out..... if you only knew the amount of times I tried to set up a tailsitter years ago using other flight controllers....this seems too simple to be true.... now to dust off a few old wings.... and print some more glue on motor mounts..... cheers
I have built my own "tail sitter" I used iNAV in heading hold mode. I find the transition of roll to yaw and vice versa confusing, although given in my case, I don't need it to land in hover; given I have an advantage that my craft can do high alpha up to a hover. IMO the advantage to roll and yaw switching is in tilt rotors. Still a feat to do it all on your own code.
Hi. Thank you for your impressive video. I have a question about the transition from horizontal to vertical orientation. Can you explain the physics behind this transition? Thank you so much!
This is an awesome project! I love things that are mechanically simple and reliable yet work really well. One thing I don't agree with is the "quadcopter" control layout when in hover mode. As an rc pilot with 30 years experience. My brain naturally would tell me to fly this plane shaped vehicle with an airplane control layout. Using the yaw stick to control yaw as if it was pointing straight up, and roll to twist around the vertical axis. This would also make the configuration much simpler.
This tailSitter looks so much fun! I want to build one ❤ I found that you provide the final code over at Patron! You should totally rebundle this video as a build video, and market it as: a cheap sub 250 project you can build with your kids and have a great intro to programming 🎉 This is basically kiwico without the parts. And you buy working code by signing up for Patron 😊
THIS is the stuff I've been dreaming of doing. I built an rc airplane and thought about getting some sort of processing unit between the radio receiver and the esc and the servos. What do you recommend using, considering that my goal is to learn the needed skills and then be able to do things like a tail sitter. In short, what should I be uploading my code to? An arduino?
@@NicholasRehm hey! I actually followed your advice and am even more interested in making a tail-sitter. I'm thinking of making a wing as simple as yours - could you tell me some details about the one you made, such as weight and motors used, please? I'm worried that I might pick engines too heavy or on the other end too weak for this project
I remember designs for carrier based tailsitters for the US navy in old popular mechanics magazines. Without fly-by-wire they would have been death traps.
This settles it, I'm making a Drehmflight FC PCB thats actually made properly. Last time I tried it really wasn't up to spec, but seeing what you can do with it tells me it's worth it to go again.
Check out @michaelrechtin's 3d printed quad project...he made a pretty sweet pcb breakout and I have a few on my desk now. Here is another someone made: github.com/joerenteria/dRehmFlight-PCB
Great video. Love how you explained different aspects of the problem the approach to resolve it. I am thinking of buying a teensy and build one of these. Will it work on a nano goblin which has only one motor or will need a lot of tuning and changes to the code?
@@NicholasRehm thanks for the reply. I was more interested in the hover actually to make the nano goblin a vtol. Any specific reason why this would not work?
@@NicholasRehm will putting this on a heewing t1 ranger hover it? That has 2 motors but a real elevator instead of elevons. I am assuming no. But just confirming.
Very interesting. VTOLs are on my list for ages now... I did some contraptions years ago, but the electronics/hardware were a limiting factor, not now tho. Next thing, deciding on type of VTOL, less dead weight + less moving parts = grater efficiency... so this type looks very promising, but as usual, it got downsides... I'm very interested where are you going with this, keep us posted :-)
Primary downside of this particular design is susceptibility to wind, further complicated by reliance on motor thrust for control authority (ask me about how easy it is to control while descending at low throttle….). I’ve got a design I’m cooking up that I think solves some of these issues at the expense of a little more mechanical complexity!
I wonder what happens if you use pitch input as a transition fader, for 90 deg pitch use all hover, for 0 deg pitch use all airplane control settings, and mix proportionally for all pitches in between. Maybe you won't even need a dedicated switch, but instead, push the stick forward to transition. I mean, remove the notion of two different modes altogether and use a single control law for both, blending two different control laws based on the current pitch?
Hey. I really admire your work on dRehmFlight. But ı couldnt find a source that explains how to use it as a stabiliser for fixed wing aircraft. A short video would be perfect! ı have bought a teensy 4.0 and ı am trying to use your code as a stabiliser for the plane ı am making right now (2.6m wingspan. it's kinda big)
Hi, I'm new, trying out a tail sitter VTOL. Am I required to use a CW+CCW motor combination? Or I can just use a CW+CW to make this work? I would really like to know. I'm so inspired to make one of these. Thanks in advance!
Cheapest dys sunfun motors they sell on getfpv, some cheap knockoff blheli ESCs from Amazon, and lots of 1500mah 4s batteries. That basically flies 90% of what I build
Would it not be easier to auto-transition the controls depending on pitch angle instead of a switch input? yawservo = yaw*sin(pitch) + ail*cos(pitch) type of thing? Obviously it would cripple aerobatic flight, but that is not the goal i think.
It would be nice to know what battery, motor and props you used. I did some back of envelop figures with 300g 3S ,battery 2x50g motors and with all the lighter items I had zero grams left for the wing itself !
@@NicholasRehm Many thanks, that clarifies a lot, I'll adjust my specs. I think I've sources most of what I need. The pdf documentation is excellent, very clear and thorough. One thing that gets only passing mention is the ESCs. I ordered a Mitoot 40A model. 30g each. Oddly the lower rated ones were the same or heavier. It'll probably serve later too.
Hello Nicholas, i am new to the UAV community. I am planning on getting started with this TAIL SITTER model and learn about during the process. Can you please suggest the Motor and Battery spec for the tail sitter build?
@@NicholasRehm I have tried the single copter(Ball drone) model from Hackaday. The tail sitter VTOL fascinates me every time i look at it. Your built was the best one out there to learn. So, i thought about giving it a go. Thanks for the heads-up.
Hi Nicholas, Great progress. Have been following your videos for quite a long time and glad to see that all missing pointers of tailsitter behaviour are solved in this video. I have few queries : 1) How about putting rudder or split flaps for forward flight. Does it creates any major difference instead of thrust vector? 2) Would like to touch base with you for a project. Kindly let me know how to connect with you.
I would have taken a much different approach. I would have viewed my aircraft as only having 1 forward direction. I simply would have changed my setpoints to better fit the way I want to control it. I also would have used vectors instead of Euler angles to allow the angle controller to still function, which starts to break down due to the singularity problem of Euler angles. Tackling it this way I never have to change how the aircraft views the world, but rather just how I control the aircraft, this means that you don't need to change PIDs as yaw and roll PIDs are suddenly changed and may not function as well as was hoped.
Yep, all of my process arose from the desire to work with slightly more intuitive euler angles. Your method I would argue is the "correct" way to tackle the problem
@@NicholasRehm Wouldn't it be possible to just have 2 different world views, one pitched forward 90 degrees, the angle PID controller could switch between the two, then this would be the only way you have to change the world view. Euler is more intuitive for sure, I do think with the right helper methods that a vector view is also simple enough to grasp, but still not as easy as Euler.
@@NicholasRehm Your approach is however still the correct one for something like a tiltwing aircraft, where the fuselage remains level through the transition. Though in this case the angle between the wing and the fuselage can be used in place of a switch to tell the controller what proportion of mix is necessary to give the pilot intuitive input responses.
Have you tried using a different transition curve than linear? Seems to me that a slower startup and faster transition towards the end would make it at least look more energetic.
I have a generally doubt - What is the difference between Normal PID and Geometric PID for aerial vehicles control ? I am a bit confused and It will be very helpful if you can demystify it.
@nicholasrehm thinking about making your own flight controller or a variant of the teensy board with the IMU integrated now that you are working with PCBWay?
is "yaw" spinning about the vertical axis wrt to the earth? or wrt the plane. new to all this but i was under the impression it was spinning around an axis perpendicular the wings surface
Did you play with different curves for the mode mixing at all? Intuitively, it feels like a more S-shaped curve would be nicer than the straight line you end up with.
I did not but that would be fun to experiment with! It would just be a matter of changing the fading behavior on the remapped/normalized aux RC channel
I'm sure you could port inav to a teensy but I think your question is more about adding those features to my code--so the answer to that is that its out of the scope of drehmflight
Would you recommend running features as such on say a raspberry pi? I am going down the rabbit hole of getting away from off the shelf flight controllers and am trying to figure out what skills I need to learn@@NicholasRehm
I want to demystify these sorts of drone concepts all the way down to the actual implementation. Did seeing the code help, or bore you?
It was super interesting to see the code! Makes it all more clear and interesting :)
Seeing the code was helpful, thanks!
Love seeing the code..... it takes a while for me to understand it.... never boring... I have spent hrs and hrs on your projects.
This was a well thought out application challenges/educational video; however, I cannot help to think if you had simply added two rudders behind the motor thrust-line so regardless of the flight mode you had same control inputs. Any thoughts?
Very interesting. I need to learn to code though.
This is probably the most cogent explanation I've seen about tailsitter flight dynamics. Breaking down the problems one step at a time, plus not being afraid to show code, makes this super easy to understand. Excited to see your next build!
Hearing this gives me the awesome feeling of "mission accomplished", thanks a ton!
@@NicholasRehm 🫡 Least I can do when my latest bicopter is powered by dRehmFlight!
Seeing each step was fantastic! I'm especially impressed he was willing to fly all of the intermediate steps that he knew were going to fail. It's so easy to just think through these problems and skip to what you assume is the finished solution, but actually testing the physical response of using a binary transition or not changing the forward flight gains really drives the lesson home.
"Hey look, it's RC test flight"😀. Great explanation of the transition problem.
this video actually took work to make and offers something unique. all RC test flight does anymore is drive around in a boat.
@@dronefootage2778inaccurate
@@dronefootage2778tbh tho im still here for the boat stuff (i started watching in like 2017 for the solar plane project 🤩)
@@dronefootage2778I’m wondering where your great output of high effort work is?
@@GeahkBurchill i just watch youtube
I’ve been wanting to make a tailsitter for a while now! Great video!!! Keep it up!
Thanks! Hope this inspires you to follow through with it
@@NicholasRehmwhat parameters on ardupilot should we pay attention to in order to smooth and tune our quad tailsitters? Please let me know!
The fact that you give such a good explanation into how and why you did things, makes this video to be into a whole other level. It passes from being an entertainment video to be a super good educational video + still being fun to watch. I'm exited to see the next project.
Thanks for the kind words
so smart that you put a timeline on yr advertisement.. I watched the whole ad rather than clicking ahead, because I knew the length.
This is the most impressive "unimpressive" piece of foam I've watched in a long while.
Yep, I think it's time to breakout the drehmflight board again and play with it some more! You really have made something special here with your software and videos. I appreciate you taking the time to share this stuff with the world
Nice! It's always cool to see people who are able to do physical design/builds, complemented with coding skills to solve both problem domains. Really looking forward to your large, folding design!
Thanks! Hoping to have that one flying any day now
@@NicholasRehmI hope it goes well!
fabulous video. i really like the progression: stepping through each problem on the path one at a time, and placing the viewer in the mode of expecting each change to be the last one, but then exposing the remaining issues to address
Hey thanks! It was a fun process to work through and I'm happy I could share
Thank you for adding the code in the video. It helps me to understand. I can't wait to see the next video.
That tease of a reconfiguring quad-to-fixed-wing looks VERY cool.
Nicholas, your videos are great and this one is particularly excellent. That was a great demonstration of engineering synthesis and how to systematically go about solving multiple problems. It was great that you were able to show how the VTOL behaved under the various steps of the design process.
Thanks for following along!
Great technical overview! I purchased Horizon Hobbies Xvert 5 years ago. Great VTOL and performs like your plane for transitions. This plane is a ton of fun to fly and very inexpensive. Keep it up! Love your videos.
Lots of fun tech packed into that plane!
I don't recall how I stumbled upon this channel but I'm happy I did. The way you explained all that gibberish was impressive. Keep doing what you're doing!
The only thing your “unimpressive piece of foam” needs to be my dream aircraft is a camera, vtx, and code that pivots the camera mount 90 degrees during flight mode transition. Your next project looks absolutely stunning! I can’t wait to see it! Thanks again for all your hard work and for sharing it with us. 🙏
That sounds like it would be a sweet setup. Check out my buddy peter's mini-qbit for something eerily similar ruclips.net/video/W0tthPSNnRE/видео.html
I suppose a second camera and a PWM-controlled switch would be about the same weight as a servo and linkage, with less mechanical complexity. If the camera switch signal was sent as part of the flight mode transition function, it would make the transition even simpler. Thanks for the video suggestion. 👍
Well done... Flies and transitions much smother now.
You make such brilliant, groundbreaking videos with some nice engineering work too. We’ll done Nicholas, another one in the can.👍
Thanks so much!!
Amazing in-depth vid, thanks for inspiring others!!!
You are brilliant. Everyone wants to see you build a single-seater VTOL machine capable of 1 or 2 hours of flight time, will essential avionics (com, nav, weather), and some safety features (enclosed blades or jet ; crash parachute...) ; plus a pivoting nacelle - that would be THE airborne motorcycle
That would be sweet
Congratulations. Very impressive.
This is so GOOD, Nick! 👍👍
So you basically need 2 FC profiles, different PID values, reference orientation & controls. Neat!
Also, the fade part is smart!
Flight dynamics and controls is such a challenging problem. So many important details!
Great clear walk-thru of the basics leading up to achieving stable transitions. Being able to make reasonably smooth transitions to level flight without airspeed or angle of attack sensors is pretty amazing.
The ultimate test would be to fly the tail sitter through a loop, or barrel roll ... involving transitions to hover at various points in the maneuver.
That would be fun. Wish I had more time to dig a little deeper
Glad you was able to hear what I was screaming through the screen from the beginning of your video about you need a factor changing the weight of control and two different controllers for diffenent modes. :D
Bruh..... this science of yours seems a lot like magic 🤯 (nice work!)
Hopefully a little less mysterious once its broken down!
Reminds me of something :)
I was planning to try the gradual transition sometime, but using a little simple sin/cos scaling. Seems to me that the relation to gravity magnitude is what matters, and that does not change linearly with pitch angle.
Maybe not gravity... It's true the gravity stays constant but I think the distinction is because regardless of pitch angle, air provides the same control authority from a control surface regardless of the direction that the plane is flying. Air gives the same resistance regardless of whether you fly up or sideways.
dude, i always love your videos. Now they are getting funny too with your crazy humor😍🤩
As a programmer, as soon as you had the violent transition working I was like, ok nice, the final step is just an easy lerp from hover to forward!
Very nice video ! Especially great that you let us in on the engineering process. ❤ this !
Perfect..... are you putting the raw code up like you did with the F35? This would be awesome to have... or is it documented somewhere. cheers
I think I'll be doing a write up on the rcgroups thread and I'll post it there--excited to see what you cook up! Hope you're doing well
That would be awesome....... I have tried a few tail sitters but nothing worked hence the excitement and comment.. Still flying the F35, made a few tweaks to the transition timing so its dialed in and does not dip down when going into FFF..... I have the Nemo set up ready just waiting to assemble the printed parts.. also have another teensy ready to be set up for a small F18...... I was wondering how big a plane you could use this board on as I have a few larger foamies that I want to try it on just for stabilisation.... as for me I just retired 3 months ago and we have been travelling and just relaxing..... if you want to see some of the plane stuff I have been doing since retiring feel free to check out my YTch ... I hope all is well there with you, stay safe and keep up the great work.. BTW I still check in the RCG thread to keep up with what is going on... cheers from downunder
@@NicholasRehm
Awesome work! Incredible what a single - very intelligent and hard-working - individual can do. Many thanks for the fun and inspiration.
Thanks for the kind words!
No problema señor@@NicholasRehm. Keep up the good work!
Well that freaked me out.
I was across the room listening to the end of the video and I hear (seeming to come from someone in the room) “hey look it’s RCTF” and of course the next thing I hear is Daniel’s voice as a video I had started yesterday auto-played. I was utterly confused for about five seconds. Well done lol
That's hilarious hahah
Hey, I know you aren't impressed with your "piece of foam", I am impressed. I've been trying to get a plane working but struggling with the balance because I have older, heavier equipment.
Basically, another awesome job! Well done.
Thanks for the comment, keep at it with your project!
The code is very clear and simple and well written. Thanks for making that available, it helps see how all this works. Have you done any more on the spinning 3-wing drone. I love the way it looks in straight flight. You left a teaser at the end of "part3" but I don't see anything since and that was a year ago.
Very well explained! Outstanding! I'd like to fly a foam VTOL like this!
You have a great talent to explains things
Appreciate it!
It's an interesting coincidence that the RUclips silver play button and quadcopters both have 4 corners🤔👀
Great video, keep it up!
Great project! Thanks for the video, Ill be waiting for more!
Hey thanks!
Looking forward to your next Tailsitter larger project.
Love how to showed the code and talked about how. Peeps leave out the details so thanks for the info cause I want to do this shit but I ain’t that so any info is awesome!!
I made this video for curious people exactly like you 😄
You have some AWESOME videos! Thank you!
Hey thanks!!
I get how a smooth transition between hover and forward flight is better, but dang that sharp transition looks kinda badass, too.
Loved the video. I just finished a project using the ESP32-S2. It was a big one. 1.1MB in Flash.
I know even the ESP32-S3 doesn't have the power of a Teensy 4 (@600MHz), but does it have the power to run your code decently?
Would it be the clock speed (240MHz) that's not fast enough? Was ESP32 available when you wrote your code? Or you just went with the best and biggest horsepower?
6:23 looks yummy! Soon I hope...
Some people have ported the code over to the esp32-s2 and said it runs just fine. The teensy 4 has STUPID compute overhead for this relatively simple code, I just like having the option if I want to load it up with other stuff :)
@@NicholasRehm Great. I hate to learn yet another hardware.
@@NicholasRehm interesting, also did they use Arduino or ESP-IDF? Also i am not that surprised it runs well on ESP32-s2 since unlike an arduino uno or RP2040 it has a floating point math unit and for the type of math that you are useing it is a great gain in speed. Also remember NOT to use core0 when useing the WIFI/BT since it may lag important code running on it .
The tensey 4 was a huge overkill to begin with (unless you wanted to ad video/photo to SD)
This is an awesome project and walkthru for the "hover to forward" flight problem, I followed your thoughts the whole way and it is so satisfying! One thing I'm not sure about is at 8:20, did you set the fade transition time on a fixed timer, or is it something else that's controlling/adjusting how fast or slow the fade phase should be?
Thanks for answering my question and for creating such awesome content, keep up the amazing work!
It's on a fixed "timer"--in reality it's just rate-limiting how much that variable can increment with each flight controller loop if that makes sense. I tune that increment size which directly corresponds to total time from 0 --> 1
@@NicholasRehm as your flight controller loop has a fixed frequency, a fixed rate also results in a fixed transition time... or where am i wrong?
Awesome video, excellent well done.
Amazing video, thank you very much!!! Can't wait for the next one...
Thanks for the arduino version added to the RCGroups page... now to sort the wiring out..... if you only knew the amount of times I tried to set up a tailsitter years ago using other flight controllers....this seems too simple to be true.... now to dust off a few old wings.... and print some more glue on motor mounts..... cheers
I have built my own "tail sitter" I used iNAV in heading hold mode. I find the transition of roll to yaw and vice versa confusing, although given in my case, I don't need it to land in hover; given I have an advantage that my craft can do high alpha up to a hover.
IMO the advantage to roll and yaw switching is in tilt rotors. Still a feat to do it all on your own code.
Love your videos. You're a great engineer.
Thanks!!
Thank you man! Great to do :)
great explanation, detailed and clear.
Not sure if you realized, but at the end with the scaling factor you reinvented “fuzzy logic control”
I guess you're kinda right!
Really interesting video!
Do a short video on the hardware and programming environment you used for your development, Nice Video
great video.
Hi. Thank you for your impressive video. I have a question about the transition from horizontal to vertical orientation. Can you explain the physics behind this transition? Thank you so much!
Yea
This is an awesome project! I love things that are mechanically simple and reliable yet work really well.
One thing I don't agree with is the "quadcopter" control layout when in hover mode. As an rc pilot with 30 years experience. My brain naturally would tell me to fly this plane shaped vehicle with an airplane control layout. Using the yaw stick to control yaw as if it was pointing straight up, and roll to twist around the vertical axis.
This would also make the configuration much simpler.
Agreed, sometimes my brain confuses me too being primarily an airplane guy. Thanks for the comment!
This tailSitter looks so much fun!
I want to build one ❤
I found that you provide the final code over at Patron!
You should totally rebundle this video as a build video, and market it as: a cheap sub 250 project you can build with your kids and have a great intro to programming 🎉
This is basically kiwico without the parts.
And you buy working code by signing up for Patron 😊
this is indeed the easiest way to transition. Cant wait for the big project!
This would be a great way to get beginners flying.
THIS is the stuff I've been dreaming of doing. I built an rc airplane and thought about getting some sort of processing unit between the radio receiver and the esc and the servos. What do you recommend using, considering that my goal is to learn the needed skills and then be able to do things like a tail sitter. In short, what should I be uploading my code to? An arduino?
I'd say build a regular rc plane first before overcomplicating with a flight controller. Direct RC receiver --> servos and motor, works just fine
@@NicholasRehm yes, I already have the plane built, my question is what flight controller would you recommend, basically
@@NicholasRehm hey! I actually followed your advice and am even more interested in making a tail-sitter. I'm thinking of making a wing as simple as yours - could you tell me some details about the one you made, such as weight and motors used, please? I'm worried that I might pick engines too heavy or on the other end too weak for this project
I remember designs for carrier based tailsitters for the US navy in old popular mechanics magazines. Without fly-by-wire they would have been death traps.
This settles it, I'm making a Drehmflight FC PCB thats actually made properly. Last time I tried it really wasn't up to spec, but seeing what you can do with it tells me it's worth it to go again.
Check out @michaelrechtin's 3d printed quad project...he made a pretty sweet pcb breakout and I have a few on my desk now. Here is another someone made: github.com/joerenteria/dRehmFlight-PCB
Great video. Love how you explained different aspects of the problem the approach to resolve it. I am thinking of buying a teensy and build one of these. Will it work on a nano goblin which has only one motor or will need a lot of tuning and changes to the code?
Sure you can throw it on a nano goblin to stabilize forward flight, but I don't think you'll be able to hover it
@@NicholasRehm thanks for the reply. I was more interested in the hover actually to make the nano goblin a vtol. Any specific reason why this would not work?
@@NicholasRehm will putting this on a heewing t1 ranger hover it? That has 2 motors but a real elevator instead of elevons. I am assuming no. But just confirming.
great work
Very interesting. VTOLs are on my list for ages now... I did some contraptions years ago, but the electronics/hardware were a limiting factor, not now tho. Next thing, deciding on type of VTOL, less dead weight + less moving parts = grater efficiency... so this type looks very promising, but as usual, it got downsides...
I'm very interested where are you going with this, keep us posted :-)
Primary downside of this particular design is susceptibility to wind, further complicated by reliance on motor thrust for control authority (ask me about how easy it is to control while descending at low throttle….). I’ve got a design I’m cooking up that I think solves some of these issues at the expense of a little more mechanical complexity!
@@NicholasRehm"little more mechanical complexity" - hhehhh, that's where problems and fun begins, good luck m8!
Which flight controller and what other sensors are you using
Incredible work! Do you have any thought as to the increase in range in airplane mode. Thanks.
definitely more
I wonder what happens if you use pitch input as a transition fader, for 90 deg pitch use all hover, for 0 deg pitch use all airplane control settings, and mix proportionally for all pitches in between. Maybe you won't even need a dedicated switch, but instead, push the stick forward to transition.
I mean, remove the notion of two different modes altogether and use a single control law for both, blending two different control laws based on the current pitch?
Unfortunately the ambiguities/singularities of euler angles complicates this
@@NicholasRehm Interesting, thanks.
i am impressed man , pls tell us more about this nice piece of foam. :D
Great project, results and walkthrough of your process, and learnings. What software do you use for the visuals/diagrams? Cheers!
PowerPoint haha
"The sensor fusion algorithm is not AI, unless you're an investor in which case it's definitely AI." 👏😂
Hey. I really admire your work on dRehmFlight. But ı couldnt find a source that explains how to use it as a stabiliser for fixed wing aircraft. A short video would be perfect! ı have bought a teensy 4.0 and ı am trying to use your code as a stabiliser for the plane ı am making right now (2.6m wingspan. it's kinda big)
Check out my video on how the code works, there’s some examples for how to assign stuff out to servos in the control mixer
@@NicholasRehm Will do. Thanks a lot for the Quick answer
Where has this been all my life? I'm putting this control scheme in my AIM-7 for next years FF!
YOU'RE THE SIDEWINDER GUY????
@NicholasRehm I had the big white missile, with the dual drone motors, it was technically an aim 7 sparrow
Fantastic video, is there a version of the code specifically for this tail sitter, I would like to try building one of my own?
I'll probably post the modified version from this project in my rcgroups thread sometime soon
A very informative video, many thanks.
Great explanation
Wow that works really well
Hi, I'm new, trying out a tail sitter VTOL. Am I required to use a CW+CCW motor combination? Or I can just use a CW+CW to make this work?
I would really like to know. I'm so inspired to make one of these. Thanks in advance!
Just wondering what motors, esc, and battery combo's you're using here....Oh and keep up the fantastic work!
Cheapest dys sunfun motors they sell on getfpv, some cheap knockoff blheli ESCs from Amazon, and lots of 1500mah 4s batteries. That basically flies 90% of what I build
Would it not be easier to auto-transition the controls depending on pitch angle instead of a switch input?
yawservo = yaw*sin(pitch) + ail*cos(pitch) type of thing?
Obviously it would cripple aerobatic flight, but that is not the goal i think.
It would be nice to know what battery, motor and props you used. I did some back of envelop figures with 300g 3S ,battery 2x50g motors and with all the lighter items I had zero grams left for the wing itself !
180g battery, 2x 1750kv 24g motors with 5” props and peak thrust at 900g each. Foam wing weighed maybe 100g at most
@@NicholasRehm Many thanks, that clarifies a lot, I'll adjust my specs. I think I've sources most of what I need. The pdf documentation is excellent, very clear and thorough. One thing that gets only passing mention is the ESCs. I ordered a Mitoot 40A model. 30g each. Oddly the lower rated ones were the same or heavier. It'll probably serve later too.
If anyone would like to try designing and programming this in a game I recommend Main Assembly
Hello Nicholas, i am new to the UAV community. I am planning on getting started with this TAIL SITTER model and learn about during the process. Can you please suggest the Motor and Battery spec for the tail sitter build?
If recommend staying away from a vtol as your first build
@@NicholasRehm I have tried the single copter(Ball drone) model from Hackaday. The tail sitter VTOL fascinates me every time i look at it. Your built was the best one out there to learn. So, i thought about giving it a go.
Thanks for the heads-up.
飛行制御において姿勢制御プログラムの重要性がよく分かる映像です。
市販されているドローンにも言えますが、自動姿勢制御機能が備わっていないモデルは操作が非常に難しいですね。
Hi Nicholas,
Great progress. Have been following your videos for quite a long time and glad to see that all missing pointers of tailsitter behaviour are solved in this video.
I have few queries :
1) How about putting rudder or split flaps for forward flight. Does it creates any major difference instead of thrust vector?
2) Would like to touch base with you for a project. Kindly let me know how to connect with you.
Rudder, split flaps, differential thrust--they all create a yawing moment which is the same in the eyes of the flight controller
Thanks for the revert. Is it possible to connect Raspberry Pi to this for further camera integration ?
I would have taken a much different approach. I would have viewed my aircraft as only having 1 forward direction. I simply would have changed my setpoints to better fit the way I want to control it. I also would have used vectors instead of Euler angles to allow the angle controller to still function, which starts to break down due to the singularity problem of Euler angles.
Tackling it this way I never have to change how the aircraft views the world, but rather just how I control the aircraft, this means that you don't need to change PIDs as yaw and roll PIDs are suddenly changed and may not function as well as was hoped.
Yep, all of my process arose from the desire to work with slightly more intuitive euler angles. Your method I would argue is the "correct" way to tackle the problem
@@NicholasRehm Wouldn't it be possible to just have 2 different world views, one pitched forward 90 degrees, the angle PID controller could switch between the two, then this would be the only way you have to change the world view.
Euler is more intuitive for sure, I do think with the right helper methods that a vector view is also simple enough to grasp, but still not as easy as Euler.
@@NicholasRehm Your approach is however still the correct one for something like a tiltwing aircraft, where the fuselage remains level through the transition. Though in this case the angle between the wing and the fuselage can be used in place of a switch to tell the controller what proportion of mix is necessary to give the pilot intuitive input responses.
Have you tried using a different transition curve than linear? Seems to me that a slower startup and faster transition towards the end would make it at least look more energetic.
I have not but that would be fun and easy to play around with! Agreed that profile might give some benefits
I have a generally doubt - What is the difference between Normal PID and Geometric PID for aerial vehicles control ? I am a bit confused and It will be very helpful if you can demystify it.
Would be fun to try a servo on a hinged motherboard, change the angle relative to the wing instead of software.
People have definitely done that in the old days of RC flight controllers
@nicholasrehm thinking about making your own flight controller or a variant of the teensy board with the IMU integrated now that you are working with PCBWay?
could you share the process, code, component , and step you followed for us to recreate those amazing fom project 🎉🎉🎉🎉🎉
is "yaw" spinning about the vertical axis wrt to the earth? or wrt the plane. new to all this but i was under the impression it was spinning around an axis perpendicular the wings surface
Would it help to read forward airspeed using a pitol tube, set a target airspeed, and base your transitional mixing on those.
Is it possible to get a guide on how to build the foam Plane?
Your channel are so good that I unsubscribed and subscribed again! Nice project, keep them coming! Thank you!
Thanks!😁
Did you play with different curves for the mode mixing at all? Intuitively, it feels like a more S-shaped curve would be nicer than the straight line you end up with.
I did not but that would be fun to experiment with! It would just be a matter of changing the fading behavior on the remapped/normalized aux RC channel
Vtol amazing. Great movie.
Nicholas, could you potentially run features of inav on a teensy? i.e. RTH, OSD, etc?
I'm sure you could port inav to a teensy but I think your question is more about adding those features to my code--so the answer to that is that its out of the scope of drehmflight
Would you recommend running features as such on say a raspberry pi? I am going down the rabbit hole of getting away from off the shelf flight controllers and am trying to figure out what skills I need to learn@@NicholasRehm