New to UAV need info.

[badinstincts]

Hi, I'm quite interested in making a UAV, I'd build my own plane and deal with the power system. But I have no clue on what I would need for the guidance system. I was hoping that I can set it up so the plane could take off and land on its own, or at least land on its own. I guess it could land on the soccer fields near my house, or if its accurate there is a strip of pavement 20' wide by about 300-400feet long. If not I guess I could take over once the plane is back in tx range.

Well I want to be able to fly my plane like 20 miles away and back, I want to take video of the ground that it flies over (but I'll be able to handle that), I just need to know what I need other than the regular power system. What do I need for the GPS, which GPS, what controls the plane and how does it control it. Does is use rudder, or can I have ailerons, can it fly a delta wing, how does it control altitude? I can settle with it flying 1000 to 1500feet high. I dont want to crash into the Empire State building or anything... Yea I'm in NYC...

Please let me know what I need and where to get it... Thx

[badinstincts]

I would also like a handheld unit that tells me exactly where the plane is when its on its mission. And I want the system to be accurate enough that if the signal is lost for a period of time it can either just keep heading straight (but increase altitude slowly until it gets a signal), turn 180 degrees around and return to base, or keep on track somehow...

[radiohound]

I was hoping that I can set it up so the plane could take off and land on its own, or at least land on its own.

Well I want to be able to fly my plane like 20 miles away and back,

I can settle with it flying 1000 to 1500feet high. I dont want to crash into the Empire State building or anything... Yea I'm in NYC...


"Badinstincts" .... hmmm...

You are talking about a very complex autopilot, perhaps closer to military grade than anything else. Just forgetting all the R/C laws, and other laws (because that is what you would have to do at 1500 feet, being out of range of manual control, and flying over a city like NYC) ,it would be a very expensive unit.

And to top off the other concerns, you are landing the craft unattended? at a park that would be populated with humans .... unless it is a dog park, I guess.

Most autopilot devices that are available to consumers require manual flight for take offs and landings.

Good luck, and be safe!

[badinstincts]

I guess I'll be fine with landing manually. I figured we would already have some auto pilot that can land, but if not then I guess I'll do it myself. I'm not going to be flying over Manhattan, I'd probably get arrested for that, I'll stick around brooklyn and staten island, mostly low populated areas, I want to fly over the ocean mostly and along the beaches. I live in Coney Island, so I dont think people would mind... There are barely any people in the park, its a soccer field and they only play after work, 5pm- 8pm... I have over 5 years of experience with flying, mostly 20-30" 100mph+ planes... and I can land perfectly every time. :D

I just need to know what I need to have autopilot..

[badinstincts]

I'll take a guess, I just read some stuff and I'm guessing that I need a GPS, dunno which one yet, a RCAP2 and an FMA copilot... Is that all? Do I need to program anything, is it already set up, where do I enter the waypoints, etc, etc... So I pretty much just get the plane to a comfortable altitude and activate the RCAP2 and Copilot and off it goes?

[badinstincts]

What if its cloudy and the plane kept climbing till it was over the clouds? what do you do then? thats why I want to have a handheld unit that tells me where the plane is...

[radiohound]

You might want to try these guys: http://www.u-nav.com/product.html

They offer an optional transmitter and receiver for ground station so you can see real time flight data.

[kd7ost]

bad instincts,

You might want to read these to catch up a little. It's a bit of accumulated information about the GPS guidance system's with a handheld GPS, as well as FAA rules concerning the application.

Truth be told, to do what you're asking is quite possible. But not necessarily a good idea. The FAA is currenlty working on ruling that will establish how we operate in the future. There are many justified concerns that guys operating small UAV's have when it comes to operating over long distances. It could reflect poorly on us and cause the ruling to be more harsh than need be.

Dan

http://www.rcgroups.com/forums/showthread.php?t=475531
http://www.uavforum.com/library/faa_uas_policy.pdf
http://www.micropilot.com/

[badinstincts]

hmm that micropilot seems very very nice. although quite expensive. I figured it wouldn't cost more than $500 for everything these days. I guess I'll just start learning to program again and figure out how to do this stuff on my pocket pc. I'll definitely remove the lcd and the casing to keep the weight low, but I'm sure i can make a fully functional uav that can fly really really well... I wonder how much I can get for that piece of software, the government would be interested, heck I'll even start work on an image recognition program where the plane could find a target itself and fly wherever it wants. oh the best part, landing and take off will be fully automated too. hehe, I just dont understand why it hasn't been done, or at least not available to us yet, its sooo easy...

[clolson]

hmm that micropilot seems very very nice. although quite expensive. I figured it wouldn't cost more than $500 for everything these days. I guess I'll just start learning to program again and figure out how to do this stuff on my pocket pc. I'll definitely remove the lcd and the casing to keep the weight low, but I'm sure i can make a fully functional uav that can fly really really well... I wonder how much I can get for that piece of software, the government would be interested, heck I'll even start work on an image recognition program where the plane could find a target itself and fly wherever it wants. oh the best part, landing and take off will be fully automated too. hehe, I just dont understand why it hasn't been done, or at least not available to us yet, its sooo easy...

Do it all for < $500 and you'll have yourself a product ... especially if you have good range, good payload capacity, and rock solid reliability and a spotless safety record. If you can add vtol capability and fit it all in a trunk, that would be nice as well.

[kd7ost]

oh the best part, landing and take off will be fully automated too. hehe, I just dont understand why it hasn't been done, or at least not available to us yet, its sooo easy...

Yes, at the risk of sounding cynical, how about you prove that to us! I think the more you learn, the more you’ll realize there are things you haven’t considered. The devil is in the details. ;)

Dan

[badinstincts]

well, the range, and payload capacity is all up to the airplane. I'm just going to make the auto pilot software that will control the servos. The system will keep the plane perfectly stable at all times and fly efficiently, controlling throttle, ailerons, rudder, etc. I plan on using it on a plane with ailerons and rudder.. for simplicity and since you really dont need more control surfaces than that... heck i'll even be able to loops, rolls, jackknife, anything you can pretty much do with the radio... oh and fly 5feet off the ground, while sensing its height with a couple of lasers, the system will be a true autopilot...

[badinstincts]

it will take me a year to finally have a perfectly functioning system, I do need to get the lasers that measure height, either gyros or co2 sensors to keep the plane level, i have to convert all the inputs so my pocket pc can read the instruments and control the servos according to my specifications, or any specifications that will be set for the flight, i'm pretty much making a sort of flight simulator program, but converting it to be an actual auto pilot...

[kd7ost]

Cool,

It sounds rather ambitious. Just be safe to airtraffic and folks on the ground. Let us know how it's going as you move along.

Dan

[badinstincts]

the reason why it will be so easy is because its a computer, all I have to do it make a program that is constantly checking the inputs from the lasers and sensors, convert those inputs to numbers, and have IF functions running constantly, and have THEN functions control the servos in each case, so say if the plane starts rolling 1 degree, then the servo will compensate for the roll until the plane is perfectly level at which point the servo will return to the neutral position. it should work for any plane although unstable planes will be constantly adjusted, I guess the rates at which it adjust will have to increase, that can be built into the software, its pretty easy, I'm not new to programing at all, this is all basic stuff, If i wanted to get complicated I can keep taking inputs and making a database on the flight characteristics of the plane and the computer will be able to adjust its values for how much servo movement it needs to do to compensate for a particular turn or leveling out or whatever, at which point it will be able to do those moves more smoothly and more efficiently... ( I can even build in an amp draw reading that will fly the plane at its MOST efficient speed and AOA, and even have a safety system that would make sure I dont fly out of range (taking wind speed into consideration).

[badinstincts]

I'm sure there would be a lot of angry pilots once I finish this software, there will be no reason why airlines wouldn't want it, they wont need pilots anymore, the planes will fly much more smoothly and efficiently, as well as being very effective, the only issue would be to keep hackers out, I wouldn't know how to make a firewall or anything, but I'm sure there could be a way that it would be a unique system where hacking wouldn't be possible...

[twinturbostang]

the reason why it will be so easy is because its a computer, all I have to do it make a program that is constantly checking the inputs from the lasers and sensors, convert those inputs to numbers, and have IF functions running constantly, and have THEN functions control the servos in each case
This is 95% of the work right there. And that's A LOT OF WORK. There are SO many variables about free flight in a three dimmensional space. Aerodynamics of the plane, thrust modeling, wind velocity, direction and gusting, thermals, terrain mapping, position and orientation of the plane, etc. etc. That's a lot of stuff to be concerned with. You are also going to have to incorporate gyro, accelerometer, laser, etc. sensors with GPS data. Most of the cheap GPS units don't update faster than 1-2 seconds. Imagine how many stick inputs you make a second during a landing. Your system will have to be very fast in order to account for the very slight and subtle movements of the plane during a landing approach. This is just one example. When you start to think about what all is involved, you will probably realize it's going to be very complicated. I'm not saying it can't be done. It can be. Just look at the Predator and other full scale UAV's. But, it's definitely NOT easy!

Good luck, and keep us posted on your progress!

[badinstincts]

it is complicated its like 100 pages of code. Once I decide to get complicated and start gathering flight data into a database we will be looking at a gig of data, thanks to the new compact flash and secure digital cards I'm not worried about storing data, the only issue for me would be to convert the readings from the lasers, gyros, etc into the pocket pc... once i get that its all a piece of cake,

oh yea, the only thing i dont like is the gps, i'm sure it would be great as a backup sensor for determining location, but I just dont like the fact that I need to use outside data. i guess I'll use it in my first system, but I will have to make some software that will make its own maps from video and a few lasers or something that will read height and distance, I guess I will have one laser perfectly vertical and one at 45 degrees and just figure out the distance that way, i'm really good at math, all my schools were for students specialized in math and science and I was either top or 2nd best student in math and science, followed only by a chinese kid who studied a lot, I didnt study at all...

[kd7ost]

What kind of lasers are you talking about hitting the ground with? Will they be optically safe lasers like in the Police laser guns? Will they be visible so local citizens might get concerned? Not trying to put the brakes on here but there is a lot to consider. Including safety of people and property not involved with your operations. Lasers are not a good sensor of choice for this application so I wonder if your sign on name is a little too spot on? The military and civil builders wouldn’t touch anything guided by laser unless it's a smart munition. GPS is the desired device for location control. OEM GPS sensors are pretty fast. If you’re thinking of using a geko, eTex or the like, you likely don’t know very much yet about what GPS units are available and desirable for this application. I wouldn’t even think of lasers. Radar is much easier to employ. It’s easier to read bounced signals happening at the speed of sound than the speed of light.

Oh, there’s always that FAA certification process before Boeing rids the cockpit of a couple of seats and puts in a laser guided passenger hauling device. I wouldn’t fly in one. (Hello, Earth to Bad instincts) Start with a platform that will haul you're experiments and see what happens next.

Dan

[badinstincts]

i dunno what kind of laser, probably an infrared, so its not visible, i figured that those laser distance measurers would be good to use to measure the planes' height I would just set a couple of them at specific angles and measure the ground distances. But I'm thinking that it would be too complicated, I think I'll just go with video, and set it up so it selects a few targets and tracks them as the plane moves over them, but I guess I would still need the laser to measure the distances between the targets... Unless I could figure something else out...

[badinstincts]

i'm not too familiar with how radar works, but it might be an even better idea, i'll do some research when I become serious about doing this project. The software is a piece of cake, the only issues I have is that I want the plane to be 100% self reliant, I dont like the 1-2 seconds of blind flight, I want constant tracking that is accurate to the T, i'm starting to think that the only reliable way is that I use video, especially for flight below 100ft, but radar may work if it does what I hope it does.

[radiohound]

Keep in mind that most affordable "laser" measuring devices are actually sonar based. The Home Depot and Lowes or Costco devices all work on sound, since it is much slower and easier to measure. But it does come with a $5 laser pointer so you can aim the device at the wall!

Your laser sensor is going to bring you back in the range of the $5000 autopilots when you are done. I would go with differential GPS if you are going through the trouble. Everything else sounds so easy, you might as well throw it in to make it more challenging.

[badinstincts]

well fine, no lasers, what other way is there to measure the altitude? I guess I will have to set a camera at a specific angle and then do the rest with math and software... is there a way to measure speed, airspeed, with some device, other than gps, that would be small enough to go on the plane?

[badinstincts]

I guess I will have to hope I make some good money on my first GPS guided autopilot and then when I have enough money I can start working on an independant system that could fly 5ft off the ground.. with gps I'll keep it well over 100ft high.., but I will have it take off and land on its own, I think I can manage that...

[badinstincts]

hahaha, i just figured out how I can keep the plane level, the same way they keep cruise ships level in storms, that is if the co2 sensor or whatever isn't good enough...

[twinturbostang]

Everything else sounds so easy, you might as well throw it in to make it more challenging.
LOL :D

[Tuner]

Comming from somone who has experience in various areas applicable to this field yet who is just getting started into it. I can confidently say your extreamly underestimating the difficulty in UAV's.

If you got 5-20 grand to play with Dive in.

Just don't be illusioned by how simple things may seem. Comming from personal expereince.

Scott

[twinturbostang]

I think it can be done for cheaper than that. But the TIME involved in writing the software required for the fully autonamous control that he is talking about is HUGE. Not to mention the electronic circuits that will be required. This is of course assuming that most everything will be scratch built.

[badinstincts]

no, i'm going to be using a pocket pc. I will write a simple vb or c++ program that would take the inputs from the sensors and then control the servos according to how I want the plane to fly and where I want it to go...

[IAmRoko]

If you're serious about this, I'd recomend picking up a few books on the subject. I recommend the following book as a start: Aircraft Control and Simulation
http://www.amazon.ca/exec/obidos/ASIN/0471371459/qid=1142960763/sr=8-3/ref=sr_8_xs_ap_i3_xgl14/701-4621806-9380343

Also, a quick google search yielded this example of pitch control of an aircraft, of course it's a very simple version that neglects many factors...
http://www.engin.umich.edu/group/ctm/examples/pitch/Mpitch.html

I graduated from Electrical Engineering last year, specialising in control systems, and have worked on a UAV using the MicroPilot system. I'm now working on my own autopilot/UAV and this stuff still gives me a wicked headache. It's do-able, but not "simple". Of course the links I've provided are for robust control. You could bash it togethor in an easier fashion, but with the large risk of having a gust of wind throwing the control system out of whack and having it crash into the ground/building/person

[badinstincts]

well, if the sensors do their job right, giving accurate numbers, then I dont see a reason why the software couldn't handle the job...

[Crazyrcer]

well fine, no lasers, what other way is there to measure the altitude? I guess I will have to set a camera at a specific angle and then do the rest with math and software... is there a way to measure speed, airspeed, with some device, other than gps, that would be small enough to go on the plane?You could just use a barometer to measure altitude, like the Zlog and other devices use. For airspeed you could use a pitot tube, like Eagletree Systems uses. A GPS will actually only show ground speed. Which could still be handy for measuring wind speed and wind gusts.

I hope you have a big pile of cash waiting to be spent.

[badinstincts]

why, are these sensors expensive? maybe i could figure out a way to visually measure speed and location, using the outline of the terrain and a map that would match the terrain, for distance and speed I guess I could identify objects such as cars and approximate their size and that would help me figure out altitude and distances... Its much more complicated, but you guys are making it seem so. I didn't think a sensor for altitude would cost much, a copilot isn't that expensive, I would just use its sensors to keep the plane level, what else do I need, I will use a gps on the first system, so thats not expensive. I was thinking I could do it for $500 or so... I already have the pocket pcs, they are only like $100 for a good one, HP Ipaq 2215, its good enough (400-500mhz(overclocked))...

Its just going to keep track of the sensor readings (numerically) and then just use a goto function and run whatever I instruct the function to do, so there will be constant goto, ifs and thens, simple...

[caseih]

My buddy is doing a UAV for a senior project. They are using a Multiplex EZ-star. Even though they already have 80% of the code provided them by a commercial company that does R&D into UAVs, he can attest that just doing attitude (climb-rates, pitch control) control is *hard*. They have finally got their plane flying waypoints and doing automatic landings. But it has taken them a lot of effort to get to this point. We're talking the product of months of development in the research lab (graduate students and faculty with years of experience). And even tuning the autopilot to do constant climb, proper turns, etc, took a long time. To say nothing of dealing with cross-winds and other typical variables. It is not just a simple VB loop exercise. In fact there's much more to an autopilot than just a simple negative-feedback loop. There's trigonometry, statistics, linear algebra, and even AI (which is more than just predicate logic). But certainly the negative-feedback loop is a part of it. Their current system has three sets of feed-back loops, but the number of variables is quite a lot. You have to take into account things like effort, rate of change, current state, etc. Is your plane moving because a servo is extended or is it because of the wind? How hard should the autopilot try to implement the desired parameters?

To me it sounds very fun, very doable, but very difficult. You will want to begin by implementing a virtual autopilot to control a simulator. Flightgear has a good API for interfacing with the flight model and the virtual aircraft. This makes for a good test platform. There's an open source simulation package (other than FlightGear) that my friend's team has been using. I'll have to post a link when I find it out.

[RetroFlight]

I'm also a novice to some degree. I would like to apply UAV to a high power model rocket glider (glide portion only). My flights would be out in the middle of some god foresaken desert dry lake bed in FAA (waiverd) controled airspace to ensure no other aircraft is any where near. And at even the slightest hint of a problem the glider will be programed to abort pop a chute and float back down. Doing what you're suggesting anywhere near a populted area would be risky considering the legal liabilities should something go wrong. I would strongly advise you to obtain FAA approval first. I'll posting my mission profile on the UAV form soon to for experienced advice.

[clolson]

I'm also a novice to some degree. I would like to apply UAV to a high power model rocket glider (glide portion only). My flights would be out in the middle of some god foresaken desert dry lake bed in FAA (waiverd) controled airspace to ensure no other aircraft is any where near.

Hehe, I've driven through Iowa many times, and god forsaken might be one thing, but I never saw any dry desert lake beds. :-) Lot's of farmers out fertilizing their fields this time of year though.

Curt (from Minnesota) where our farmers are still probably all out ice fishing.

[RetroFlight]

Iowa is a great to fly R/C with several well established clubs. Flying rockets has limitatons. Corn fields can swollow up and hide even the best GPS locating systems. And obtaining waivers over 5K' AGL is difficult due to the large volume of commerical jet flights on approach or taking off.
I head out to the southwest to fly the big stuff, lots of room with few worries aside from an occasional rattler.

[kd7ost]

I'm also a novice to some degree. I would like to apply UAV to a high power model rocket glider (glide portion only). My flights would be out in the middle of some god foresaken desert dry lake bed in FAA (waiverd) controled airspace to ensure no other aircraft is any where near. And at even the slightest hint of a problem the glider will be programed to abort pop a chute and float back down. Doing what you're suggesting anywhere near a populted area would be risky considering the legal liabilities should something go wrong. I would strongly advise you to obtain FAA approval first. I'll posting my mission profile on the UAV form soon to for experienced advice.


You would actually use FAR 101 Subpart A and subpart C. ;)
http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=ea968eea871ed9ab2380f6d979eaa7a6&rgn=div5&view=text&node=14:2.0.1.3.15&idno=14

Dan