newbie UAV for AP usage [Archive]

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rbno

Apr 16, 2006, 04:21 PM

Hi all, just firstly to say what a great resource this web site is. Also, I am totally new to RC aviation so bear with me on this but I learn quickly which is some consolation.

I´m studying the feasibility of starting up (part time to start with) an aerial photo company but geared towards agricultural applications, i.e. crop stress analysis. I live in southern Spain, and as many of you may know Spain is the bread basket of Europe. However, much modernisation is required within this field, hence my idea. Now there´s a set up that already does this, www.cropcam.com, I reserve judgement on their product as I am awaiting for them to get back to me on details price etc. However, could you guy´s advise me on which rig would serve me right, I have no preference as to whether it should be powered by electricity, petrol or glow plug etc. I would require a strong and sturdy performer that can deal with the rigours of flying a lot and landing on hard and dusty runways. It may fly in inclement weather conditions also even if it´s just to support moderate to strongish winds.

I am also thinking along the lines of an gps autopilot system so I guess you could even call it a UAV with off the shelf items. I would also, be looking at installing some sort of telemetry with video downlink. So payload capacity is also an issue.

Also, you photo knowalls have any ideas on NIR camera´s, even home made versions, I´ve read a few interesting threads on this but have yet to find the definitive set up. This area intrigues me most!

I guess what I´m asking for is for an aircraft that has long endurance, good slow speed capability, strong, good payload capacity, reliable motor.

Any ideas and or directions are greatly appreciated.
many thanks up front to you all

Richard

kd7ost

Apr 16, 2006, 06:19 PM

Hi Richard,

There are a lot of directions to go and variations in cost for different platforms etc. Transportation is an issue. I'm doing what you're describing but not with any multi spectral camera's yet. That's a huge cost jump. I meet the rest of your requirements and take pictures for a large Ag company in the Northern US. We're definitely riding the cusp of development for the Ag community. The pictures aren’t worth much though unless the crop management types know what to do with them. I’m lucky enough to be involved with those technology folks so they bring the value to the photo product. All I need to do is take the picture and geo reference an easy to find spot in it. Intersection, well head etc.

That all having been said, I don't believe I have the best set up for all conditions. My biggest down fall is size and transportation requirements. I can loft a D20 with no problems but the camera I have in routine use is the Fuji finepix E510. It beats the snot out of satellite pictures.

I designed my own plane from the ground up. It needed to be a flexible airframe to easily accommodate cargo changes no matter what they might be. I used a gasoline powered engine because I wanted cheap long term performance. I can stop at any gas station and buy cheap fuel. I get 1 hour duration on a quart of 2 stroke gas using a Fuji BT32A magneto developed spark engine. I didn’t want an engine that needed a handheld starter or a CDI ignition with required battery pack.

I have a BP controlled altitude lock from UNAV, a Garmin geko 201 GPS unit, a GPS steering device which allows the plane to “route follow” or “goto” in order to prevent fly off’s in the event of RC link failure. All though the system allows me autonomous flight capabilities I do not use it in that manner. I cannot mitigate risk doing that. If I have control of the plane even if flying at high altitudes, in the rural setting, I can mitigate risk. I also use the FMA co-pilot employed in roll control. All the individual parts can be enabled through separate channels or the Futaba PCM system will enable all the parts if it goes into failsafe. If that happens, the plane will return overhead and loiter.

I use a 2.4 Ghz video downlink to see what the camera sees and use a GPS overlay system so I can see altitude, speed, heading, Lat and Lon etc. Sometimes I only have coordinates available to locate my field. You have to have the video downlink to frame up the shot. These are working pictures and when you have to get 600 acres in a picture you can’t just start snapping pictures and hope for the best. The downlink makes it feasible. I have a second small video camera that sits under the nose in a little tilt pod. This allows me to look ahead to line up on the field and keep lined up as I fly over head. I built a video switch that uses the pulse from the tilt camera for the switch action. Once I’m nearly in position to take the picture, the switch puts the digital camera output on the down link so I can make final adjustments with yaw and roll to frame the field then snap the shutter. As soon as I roll the tilt camera back forward looking it gets put back on line.

There are going to be other builders/pilots that will pitch in on this I’m sure. There are a lot of good ideas. I’m currently developing an electric plane that will have many of the same features I just described minus the huge cargo loft ability. My gas plane has a special camera mount to keep the vibration out. Electrics can allow you to work around that although I’ve seen a lot of electric plane pictures that still have motion blur. (That’s the pilot and shutter speed though)

I’m not trying to tell you I have the best setup. I don’t. There are lots of available technologies out there. Being new to RC I think the best thing you can do is to learn to fly well and shoot touch and goes till you can do it with your eyes shut. In the Ag AP world you’re a bush pilot. You take off and land off gravel roads, driveways, paved highways, cross wind, avoiding power lines, trees, etc. You need a good spotter. You have to be comfortable with taking off and landing in places where others wouldn’t risk it. And it has to be routine. Touch and goes. Pick windy days when others pack up and go out to practice. The biggest risk to this is putting your camera ship into a telephone pole or mail box post.

This is an old video from a practice flight and a development plane I was testing with several years back. This is just a Dead stick landing but it shows you what the video overlay system looks like. It was converted from VHS tape and highly compressed so is pretty poor quality but you can still get the idea of what the overlay looks like in flight. Lots of guys don’t like the Lat and Lon but some times I need it to help me get the right field if the crop manager can’t be there to identify it for me. I guess the choice for it there or not will depend on whether you’re working or playing. It isn’t on the picture. http://media.putfile.com/Dead-Stick-Landing

Listen to other guys jump in here though and take their advice along with mine. There’s a lot of ways to pull it off. Most are smaller and simpler than what I have going on. I will say I have over 1,500 miles on this plane either taking Ag pictures or just practicing. Rolling your own is pretty ambitious. But I have learned it’s the only way to really get what you want and need if you have specific requirements.

Dan

John Ci

May 14, 2006, 01:10 AM

kd7ost

May 14, 2006, 01:55 AM

Dan,
Hi. Do the growers do get full service through you?, i.e. fertilizer, pesticide, water recommendations? Do you work for a larger consulting firm and add value as a flying specialist or are you freelance? Have you tried a light-weight, brushless electric powered platform, glider style with great stability and predictable slow speed characteristics? Any reason besides cost holding you back from using infrared imaging for a nice stress reference that color spectrum photos cannot detect? What can you recommend to a grower based solely on a colored photo? Lots of questions because I have worked in a similar field (no pun intended) Great video regardless of res, nice to see someone using R/C for
precision Ag services.

Hi John,

I do it as a part time job. I take the pictures for Simplot Agribusiness. http://www.simplot.com/ They actually found me to start this up. The precision ag and grower solutions department has the interest and need. I do this free lance but work directly through them. I have a day job but it has some built in flexibility to allow me time to shoot the fields.

I provide no service other than the photo and geo referencing. I don't have a background in agriculture so barely know what the crop advisers are even talking about. ;) The biggest use for my photos so far is to ID effected regions in Onion fields for a weed called Nut Grass. Simplot takes my photos and lines it up with other photo software. They can then place the curser on the edges of the effected area's, draw a line around it and it will tell them the Lat and Lon of that curser location as well as how many acres are inside the outline they just drew. This provides them the information needed as to how much control substance is needed and where it needs to be placed. This saves money and prevents over or under treatment.

I have considered and am working on a brushless electric plane for some of the smaller lower altitude pictures. Taking a 600 acre shot requires a fair amount of power, size and equipment to get to altitude quickly and back down. I prefer my big plane for the high shots. Speed is not a factor then. You have plenty of time to line up and get the shot. The lower altitude pictures are the touchy ones. I drop my speed to about 30 knots and stay right on the shutter. The ground passes much faster when you're low.

Multi spectral pictures would be the way to go. It is a cost issue. A good IR camera is quite high cost and isn't real small.

Dan

kd7ost

May 14, 2006, 02:25 AM

I decided to size down a 600 acre field and post it. This was taken from my current plane. This wasn't an Ag shot per se. It had an “anomalous growth pattern” of interest. The picture has been enhanced but it’s being posted to show you an example of a high shot from RC plane and the ability to ID not so subtle issues. The Multi spectral would be very cool to see in this field.

Dan

CenTexFlyer

May 14, 2006, 09:24 AM

I have considered and am working on a brushless electric plane for some of the smaller lower altitude pictures.

Really!?!?!?..........

workshop

May 14, 2006, 12:07 PM

kd7ost

May 14, 2006, 01:59 PM

UAVers,

This is a very interesting post. Dan, you have produced an amazing aerial tool with that UAV of yours.

I've been developing my UAV (GPS-58) to loft my friend's camera and video gear. He works for FLIR and has airborne IR surveillance experience. Unfortunately, he's too busy at his day job to do any amateur level UAV work with me so I'm not going to IR anytime soon.

However, if you guys have IR camera specs. in mind (frequency, resolution, lux, etc.) let me know and I run it past him and see what options exist.

Jeff Parisse
www.teslacoil.com

Hey, Thanks across the board Jeff,

The R&D took a fair amount of time to get it all worked out. I can carry a pretty large camera with this plane. I haven't reset the on-board GPS "total running data" since I maidened it last year. I have accumulated 1,580 miles of traveled distance while testing and taking ag pictures. Thankfully it's proven to be a rock solid work horse. Things should be picking up here soon as the wet spring has finally passed and the crops are being sowed. We're actually looking at getting some Telemaster ARF's similar to your setup to have more planes in the fleet. The takeoff and landing environments are pretty harsh at times though. It's nice to have a tricycle landing gear arrangement with a wide main gear for those cross wind, past the tree, under the power line approaches to the rural road you're using as a temporary airport. :D

I don't know what specs to use or to look for in a Multi Spectral Camera. I'm actually hoping this year will see Simplot spelling out some definitive requirements and even buying the camera they want me to use. We have discussed that at previous times. It's what drove the original size and power to weight ratio of this plane when I was designing it. I do have a sense it won't be a modified consumer camera with the IR filter pulled out.

Anyhow, thanks for the offer of your resources. I will certainly take you up on that if we do get to that point. This could easily grow into a project that's too big for me to manage with a full time job and a family.

Dan

HELModels

May 15, 2006, 01:47 AM

I´m studying the feasibility of starting up (part time to start with) an aerial photo company but geared towards agricultural applications, i.e. crop stress analysis. Also, you photo knowalls have any ideas on NIR camera´s, even home made versions, I´ve read a few interesting threads on this but have yet to find the definitive set up. This area intrigues me most!

Richard

NIR = Near Infrared = .7 - 1 micron = 700 - 1000 nanometers

This is feasible with a film camera, and IR film and correct filters. It is tricky to focus since the filters are usually black and the shift in wavelength affects focus. digital cameras are sensitive to near infrared, but filters are used to block it - so you would need to hack. IR film, I think might have, was originally developed For Agriculture because it shows the relative health of vegatation, with healthy vegatation reflecting IR relative to health - something to do with chlorophyll, xanophyll and water content. Beware of film cameras that overlay IR date/time onto the image, like canon. IR with film is tricky but has been done for ages. To get the multispectral coverage, use 2 cameras, one with IR and one with regular.

Your hurdles in order of acquisition are:
1) piloting

2) airframe

3) guidance

4) data collection

rbno

May 16, 2006, 02:33 PM

I had info sent from cropcam.com, looks like a pretty impressive peace of kit even though the camera included is just a regular type. The company is a subsidiary of www.micropilot.com which is interesting as some of you already may be familiar with their products. The glider is an off the shelf unit, so I guess one could retrofit all of the electro gubbins to another plane if you so desired.

On the camera front check these out,www.maxmax.com, they modify regular digi cameras and camcorders for various uses, they say that their products are used by ag companies for NIR analysis. If you want professional stuff then check these guys out http://www.tetracam.com/ and look at their ADC camera, this is where we need to get but at about $5000 with geo referencing software and triggering etc it´s a long way off but still cheap compared with the old style of cameras!