How Does This Rocket Steer Itself? -- Active Control Rocket Avionics (Building DIAMOND-X Part 2)

[Music] [Music] hi everybody welcome back to Lafayette systems this is part two of a build Series where we are building this rocket here Diamond X it's about one meter long it weighs about one kilo in weight and it uses four actively controlled aft fins to guide itself through the air as you can see I have one airframe in the back built there this one has flown twice and both videos are up on the channel and this is the second airframe that we're building so we're going to build a second copy of it not only because eventually this one's going to end up in the dirt but because I'm going to upgrade this one even further so I can fly with an additional first stage rocket booster that lets us flat higher and faster and lets us practice control at different regimes of flight we built this airframe in part one of this build series and so if you haven't seen that definitely check it out right now in this video we're assembling all of the avionics which are going to live in the very front of the rocket and do all of the guidance navigation and control tasks and also initiate parachute deployment so as you can see here we have our primary flight computer this is consisting of two flat black circuit boards very cool we have three cameras we have our Telemetry radio unit so this lets us send commands to the rocket and receive Telemetry we have our Wishbone this mechanically connects the parachute which attaches here to the rest of the avionics assembly and is kind of a unique design so that lets us solve some load path issues this is a single large cfpc carbon fiber polycarbonate 3D printed piece and it holds all of the above we then have our flight battery our battery Mount and our gnss antenna in this box here and then a couple of other parts that hold everything together we're also going to be assembling the Raceway cable so there's a very large cable assembly that lives underneath these 3D printed uh raceway shrouds on the Block two version it only has six wires in it so there's four Servo data lines and then Servo power and ground to run all four of these servos in the back when we run with a booster we need a whole bunch more we need lines to connect to the booster other random IO to the booster we're going to need pyro channels to to separate the booster off explosively and then to fire the main rocket motor and then we're going to need even more Servo data lines this is one of the first booster prototypes here it has a single fixed 38 mm motor here the idea is to fly with a high thrust motor to get this thing off the rail and then a slow burning sustainer motor to let us practice control for longer periods of time in the future though I'm going to be building a Thrust fector control booster with no aft fins but a motor that can be actively gimbaled around to steer this thing uh straight from launch and that way we don't even need a launch rail uh but that one's going to require some more wiring and electronics so I want to build this entire system out so it can fly with the fanciest booster I can imagine and that way it's easy for the system to grow I have another video coming out on this channel very soon all about the flight computer what chips are on it what its capabilities are and what requirements I had that drove those capabilities so if you're interested in electrical engineering or the flight computer aspect of this project make sure to check that one out too so I've got all three of our main avionics assembly prints tentatively stacked together here I'm not haven't uh screwed them in quite yet and step one is going to be to assemble the wire harnesses that connect things like our Telemetry radio and our cameras to the flight computer the cameras are just connected via power and ground so I can enable the cameras uh remotely basically just by turning on their power they draw something like 300 to 400 milliamps a piece so I don't want to have them running all the time it draws too much power and then the telet radio has got a four pin it's got uh 3.3 volts ground and then TX and RX so that's how the flight computer sends data to the radio it sends it down to the ground station so I will assemble those and at least for the cameras I'll solder them to the cameras and then we'll get everything put in place and screwed together right M he's been a good lab Kitty today he been very helpful good boy don't touch your tail on that stop and here is our completed lower and middle avionics assembly so you can see the middle one we've got our circuit boards in place both of them we've got our Servo and radio connectors in place these are for Servo power and ground on the side you can see three wires in the screw terminals those are a pyro positive and then are two pyro minus lines we've got two more lines that are connected to these five pin connectors these are the booster detect and booster I/O lines and then a couple more Servo connections which are just soldered in place because I don't have a useful connector to actually pull those pwm signals off of so it's kind of a mess I've bodged a lot of stuff together but we have that all connected to our 18 pin connector here and I'm trying a new technique where I'd put a uh this is just a giant heat shrink tuber on that and then I put a bunch of epoxy in the top and bottom to make sure that there's no stress on the leads that are soldered directly to this connector PCB so this guy's done our next steps are to assemble our upper avionics assembly with our camera we also need to attach our radio and our Wishbone uh which is right underneath here to the lower avionics assembly and then mate those two with these four screws [Music] [Applause] [Music] [Applause] [Music] [Applause] [Music] here [Music] [Music] so here we have the fully integrated avionics assembly got a camera power wires connected we've got got our Telemetry radio antenna installed got our cameras in place got our GPS antenna structurally hot glued together very nice so the next step here is to connect it to the laptop upload our flight code and the flight code will start out with a self- diagnostic test looking at all of the different sensors and making sure that they can connect correctly so we'll do that make sure everything's soldered together and wired together correctly just on the ab Bay and then once that's all checked off we'll connect it to the rest of the rocket and try to get those fins to move you see the rocket starting up it's scanning its i squ c bus and it's seeing all of its sensors very nice next thing it's going to do is check that there's nothing on the flash memory and then if there isn't erase it get ready to write a bunch of new flight data to it all right flash memories erased went through a self test here and it tested all of its sensors we connected to GPS very nice it looks like it connected to all of its Imus and everything all right now it's starting frame rate driven operations very good okay that looks great so now let's connect it up to the rocket and make sure that the Raceway connector here is working as intended as well so the rocket is all integrated together got a Raceway cable connected here and right now it's clearing its memory again I've restarted the flight computer and then after it checks its sensors its inertial measurement units then the first thing it does is it sends power to the servos and then it sends them to the neutral position so we should see the fins move here in a sec I don't expect them to be straight because I haven't set their neutral positions yet we should see them move here there we go all right so our fins are now energized which is good you can see we can't move them there's a little tiny bit of backlash but this is pretty pretty good so there's our fins next thing we need to do is make sure that we align these so their neutral positions have to be set correctly and that's just a process I have to do manually and then once that's done we can connect it to the Ground Control software and actually start running uh fin test and Alignment sequences on it okay so slightly different setup here you can now see that the laptop is no longer connected to the rocket the Rocket's data link antenna which is buried in here is now now communicating to this box here which is my grounds Telemetry unit so it's got a nice big omnidirectional antenna the same XP radio and then a version of an old flight computer which translates the packets coming in from the rocket and then sends them to the Ground Control software so this is what the Ground Control software looks like this is written in processing which is basically just Java and I have a bunch of different data boxes here that list the Rocket's position velocity and stuff like that and then I have more detail here about this GPS position which uh is incorrect intentionally um and then also the Pyro channels and then other things where we can give it way points to to fly to so right now we can see that rocket is connected this box here tells us our data link status and it is strong we're receiving about seven packets per second and we can see we've received about 600 packets since the Ground Control software has been turned on down here we can see the battery current in milliamps and we can also see the flight battery voltage this is pretty low so we're probably going to want to charge the battery before we do a whole lot more testing it's temperature and then the previous frame processing time gosh that's a mou full um so this is basically saying that the rocket took 5.7 or well now 11 milliseconds to process the previous frame it should take 10 if it takes more than that that's not great if it takes less that's awesome so next thing we can do is we can calibrate its gyro and its magnetometer this shows up in our event window as we're calibrating its inertial sensors and this is going to be a little bit off because it's lying sideways so it's not going to like the calibrations It generates but that's fine so now once that's done we can vehicle safe very nice next thing we can do is fin alignment control fin alignment so now when I push these buttons we're going to change the fin positions and we should be able to align these fins manually now this process takes a little bit so we get back to you guys when that process is done [Music] okay so now that we got our fins nice and aligned very pretty the next thing that we can do is a fin test so we can see we are in control State Control fin alignment so we will click this check Mar Mark turn turn to control disabled and then we'll start a fin test we see a fin test countdown starting here we should see our fins do a little test sequence to make sure they're all moving in the proper directions all right there's our fins looking very good next thing we can test is our cameras so this is the power State for the cameras we can see we can separately actuate a 5volt mosfet and a this case VCC so 8.2 volt mosfet but all the cameras are connected to 5 volts here so if we click this enable 5 volts boom five volts on and what we should see is yep there's our little camera LED blinking so that means this camera is now recording the wall very nice and we can also see that our current draw is much higher now we're at 700 800 milliamps so if I stop 5 volts our cameras are now off and now we're down to usually around 80 to 90 milliamps so that shows just how much power the cameras draw and that's why I turn on the cameras right before launch and I just leave them running now the last thing we're going to do with Momo observing is something called the GNC test that's guidance navigation and control so what I'll do is I will pick the rocket up I will enable the GNC test and then it'll switch to a mode where it pretends like it's flying through the air you're in the way and then I will move it around and you'll be able to see the fins moving so let's start this m I'm in the middle of rocketing buddy I know we don't need to complain we don't need to complain okay so let's try this we're going to push GNC test we can see a guidance test has appeared in our events and we're just going to look at the fins you can see the fins moving around like they would inflate in this case just controlling roll was that interesting so using the GNC test feature I can make sure that the control gains are set up correctly that the rocket is correctly adjusting um you make sure the fins are going the correct direction in flight and that's how I test that on the ground so I've got the rocket vertical here and I'm going to show you what it looks like when it's pitching and yawing around so first if we pitch the rocket forward we can see we now have a 30° pitch if I pitch the rocket back towards me I now have a positive 30° pitch same thing I can yaw the rocket to the left we have a 30° yaw and same thing if I yaw the rocket to the right I now have a negative 30° yaw well folks that's all we have to do for the avionics assembly for Diamond X block 3 next episode we're going to be painting this bad boy and also working on the flight software and the Ground Control software to get integrated with its first stage booster we also need to amend the flight software so that it includes a couple of other events that it doesn't typically have in Flight like separating the booster and igniting the sustainer motor and both of those need to be ground tested before we can fly but for now I'm going to leave this project where that and we're going to get ready to fly the other Diamond Decks that one very very shortly so lots of fun videos coming up soon I really love these rocket projects so I'm glad other people enjoy them as much as I do so stay tuned for more videos coming up very soon thanks [Music] everybody

Channel: Lafayette Systems

Views: 519,319

Keywords:

Id: Z5iS-dAGq7c

Length: 15min 50sec (950 seconds)

Published: Fri Feb 23 2024