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Developer

Launching an ArduPilot Project with my daughter

Posted by Doug Weibel on August 5, 2009 at 4:53pm
Hello All,I have started into an ArduPilot project to satisfy my curiosity and to draw my 12 year old daughter out of her novels and into some practical math and science. My intent is to start with a straightforward ArduPilot set-up with the current hardware and software.The airframe I chose is the SuperStar EP. We finished assembling it last night. It is stock (for the present) except I am running a 3 cell 2200 mAh LiPo instead of the stock NiCad. With 200 grams less weight and considerably more voltage the SuperStar performs quite nicely. We are just back from 2 quick flights at the local schoolyard. My daughter learned what happens when you land in grass that is 4 times as tall as your tires :)Tonight we will begin assembling the autopilot hardware. Again I am going with the "stock" setup - DIYDrones IR sensors and shield with airspeed, and EM406 gps.I have not ordered parts yet for downlink and groundstation. I was not planning to implement that right away, but judging from some posts I have seen it may be highly desirable for debugging purposes. I'd appreciate any opinions on that as well as on using the hardware ground station versus a laptop setup.Best Regards,Doug
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T3

Recommended DCM algorithm gains for red UAV DevBoard

Posted by William Premerlani on August 5, 2009 at 1:37pm

09038-1_i_ma.jpg

UAV DevBoard Pilots,If you are using a version of MatrixNav or AileronAssist on a "redboard" that was released before August 5, 2009, there are a couple of revisions that you can make that will improve overall performance.First, you should modify the definition of RADPERSEC in the file optionsRmat.h to:#define RADPERSEC ((long long)5632.0/SCALEGYRO)Just change the definition of RADPERSEC that is already there.In the previous releases, SCALEGYRO was not included, so the scaling in the centrifugal acceleration compensation was correct for the green board only. Many thanks to Sid, who was never quite satisfied with the high acceleration behavior of the red board firmware, for motivating me to find out why. If you include SCALEGYRO in the definition of RADPERSEC, you will improve the performance of the red board firmware for high acceleration applications. Green board firmware will not be affected.Also, you should modify the rmat.c file to use the following values of the drift correction PI gains:#define KPROLLPITCH 256*10#define KIROLLPITCH 256*2#define KPYAW 256*4#define KIYAW 32Just edit the definitions that are already in rmat.c to use the above values.Based on a lot of simulations done by Paul Bizard, and a lot of flight testing by Sid, we have concluded that these values will produce the best performance possible for the red board.The gains in the first release of the firmware for the green board are very low. Although these values provide great accuracy for the green board, when I designed the red board, I was concerned about the security of locking, particularly with the 4X change in the gyro gains, so I decided to use much larger gains for the red board.The gains in the released firmware for the red board are very high. Although this provides secure locking, it is not as accurate, leading to pitch and roll errors during rapid turns at high speed.The latest values provide a much better compromise between accuracy and security.The changes described in this post have been included in MatrixNav and AileronAssist release 1.5, August 5, 2009.Thanks again to Paul Bizard and Sid for their hard work.Best regards,Bill
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Developer

ArduStation code V11 now available

Posted by Jordi Muñoz on August 4, 2009 at 11:00pm

You don't have an ArduStation yet? Came on, buy one now!Well the 80% of the work was made inside. So whats new?-I fixed the issue with the buzzer that sometimes used to drift.-Now you can record the home position and stays even if you disconnect the unit. This function will let me do many things with the board.-Now you can see the 2D/3D distance, direction and the altitude angle of your aircraft. This info will let me control the antenna and will help you spot your aircraft in the air.-I added a tiny and very funny arrow (like the OSD's) that indicates the heading and the waypoint bearing of your aircraft.-Added the new RSP = Roll set point variable, for debugging. If the value is positive means your aircraft is trying to turn right, if is negative is trying to turn left. This is the actual value coming from the navigation function and telling to the stabilization (autopilot) where to go.The next addition is the directional antenna, I'm just waiting for the material.

For those who don't know the meaning of the data, here it is:WP# = Waypoint NumberCRS = Course over groundBER = Bearing (the direction of the waypoint)GSP = Ground SpeedASP = AirSpeedALT = AltitudeRSP = Roll set pointThe code is locate here:http://code.google.com/p/ardu-station/[UPDATE] I forgot to mention that you need the replace (update) the folder called "LiquidCrystal" (is an arduino library for the LCD). The new library folder is included in the same file of the ardustation code,inside "libraries". Then just copy/paste it into the arduino IDE: "\\arduino-0016\hardware\libraries". You are done!Enjoy!

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3D Robotics

Thoughts on a commerical Lego Mindstorms NXT autopilot

Posted by Chris Anderson on August 4, 2009 at 10:28pm
I got started with amateur UAVs by making a Lego Mindstorms autopilot two years ago. It was a total kludge, using a mechanical assembly with Mindstorms motors to move the rudder, with stabilization handled by a FMA Co-Pilot. Originally, I used a compass sensor for steering, but quickly upgraded that to a Bluetooth GPS module. It worked, sort of, but then I decided to go all the way to a 5DOF Lego IMU, using some protoype Hitechnic integrating gyros and a RC MUX. Unfortunately, HiTechnic decided not to release those products, and I stopped development. (Although Sami took a version based on commercially-available gear further than I did--see photo above--he too stopped before getting it totally working). Now I'm thinking of coming back to Mindstorms. Not a full IMU-based one (the cost, weight and size of the sensors, interface boards and other necessary equipment is several times that of custom hardware like ArduPilot), but rather a navigation-only autopilot that could work with a FMA Co-Pilot to make a very simple UAV for kids. What we'd need is a custom interface board that performs the following functions: 1) RC MUX, to switch control from RC to Mindstorms and vice-versa 2) Servo driver (at least two channels--rudder and throttle--but ideally more for photos and other triggering). Here's one example. 3) A GPS interface, so we don't have to use Bluetooth Mindstorms uses a I2C interface. My sense is that if I can just add a Mindstorms connector to ArduPilot and figure out how to handle the I2C communications between it and Mindstorms, it could serve as that interface board. It would send GPS information (already parsed) to Mindstorms, and then Mindstorms would send servo information back to ArduPilot. What's the point of the Mindstorms, since ArduPilot can already perform all those functions itself? Just that it's a more kid-friendly programming environment. If we could treat the custom ArduPilot board as a plug-and-play preprogrammed device that spits out GPS data and accepts servo commands, students could focus on simple navigation logic and action controls. What do you think? Is this a good idea and worth the bother? Or should I simplify things even further and just use the Mindsensors board as a servo interface, Bluetooth for the GPS interface and a touch-sensor as the MUX (like this)?
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3D Robotics

Landing tech could let drones see like pilots

Posted by Chris Anderson on August 4, 2009 at 10:16am

From Wired's Danger Room: "One big difference between Army and Air Force drones is that the Air Force’s robo-lanes can’t land themselves. That’s contributed to a number of Air Force Predators crashing when humans run into problems. But there may be a way of providing autolanding capability without the weight and expense of conventional systems. Computer vision company 2d3 is developing a new system to allow drones to see their way to a safe landing, using their own cameras rather than radio beacons or radar." Read the rest here.
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3D Robotics

Helicopter autopilot with optical flow sensor

Posted by Chris Anderson on August 3, 2009 at 11:24pm
Spotted in the Model Airplane News magazine: an ad for "Flymentor" from Shenzhen KDS Model Technologies. It's a gyro-based helicopter stabilization system with an interesting twist. It includes a CCD camera that looks down, capturing "a ground picture" and holds the heli in one position, presumably by using optical flow. It's kind of amazing. Don't ask me how it holds altitude, but it does, very well, as this video shows:
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Changed the 2.1 for 2.0 hardware features.....

Posted by Vikram on August 3, 2009 at 9:04pm
Hi all, i m ready for the ground test.Before starting i would like to clarify few things here..I dont have Z sensor and air speed sensors soofcourse no throttle control then also... I was ok with version 2.0 but since i would like to add the config utility feature without increasing any hardware. So i made few changes in 2.1 version so that it can work successfuly with 2.0's hardware(only XY sensor).I have made these changes please confirm is it right and please tell me if any other change need to be done. Just remember i want to add config utility in 2.0...So these are the changes i made:1.#define SHIELD_ENABLED 0 //in main file#define SENSOR_Z 0 //in main file// i defined them as zero2.//infrared3= (infrared3*.99) + ((float)analogRead(3)*.01); //in Sensors filei commented this line because i dont have air speed sensor3.(in sensors file)#ifdef SENSOR_Z /// added a new linethrottle_set_point=PID_throttle(air_speed_hold, airSpeed(), t_dt);pulse_servo_0((throttle_set_point));#endif /// added a new linesensor_z();// unbias_airspeed(); //// commented this line here----------------------------------------------------------------These are the changes i made please tell me which loop enables the configutility so that i may try another way just add that function in version 2.0.
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Ublox GPS boards

Posted by Cronselaar on August 3, 2009 at 2:10pm
OK firstly... I'm a total electronic nube.No jokes!I do how ever have something that might help people who want the ublox modules but who are not "PRO's".As a student i do have a lot of time and found this in one of my favourite shops.http://www.rfdesign.co.za/pages/5645456/Products/GPS-Products/Receiver-Boards.aspThey have a whole bunch of Ublox GPS boards.The boards feature onboard power regulators, ic drivers, Bla,don't know what they are,Bla serial ports,USB ports ect.I do believe we are however interested in the serial ports, and even more so in one of the boards that feature 2 serial datalines 2Tx 2Rx. eg.http://www.alphamicro.net/resources/u-blox/RCB-4H_Data_Sheet%28GPS.G4-MS4-06034%29.pdfThere are other boards also available with the new 5H ect.Hope this is of useGerritP.s. The boards are really cheap. devide the price by 7.8 to get $

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Need help tracking UAV/ powered parachute

Posted by Connor on August 3, 2009 at 4:00am
Hello i have read about a project that some students have done and i am trying to recreate it. I want to launch a weather balloon with a uav attached to it so that it will go to about 100000ft take some pic's then return home the only problem is i don't know the best way to track it. Can anyone help please???I just had an idea for recovery and was wondering if it is possible to make a powered parachute out of a 1.8 m Dual Line Stunt Parachute Parafoil Sport Kite? or any other ideas just thought it would kill 2 birds with one stone, slow down desent of craft and help fly back to launch site.
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Ublox GPS questions

Posted by JvdB on August 3, 2009 at 12:40am
Hi guys,I've been waiting for the Ublox GPS to come back in stock at sprakfun but that seems to be taking ages.What's new on the Ublox GPS, is DIYdrones taking up the Ublox GPS in store together with the antenna? Or should we wait untill sparkfun has them back in stock?I also read somewhere that Jordi is making some kind of gizmo adapter in a way that non-pros' can use the Ublox as well without the fiddly soldering job? Not that it will be a big problem but I like it easy.I've been actually waiting for a couple of weeks now on the Ublox GPS becasue this is the GPS I want to use on my easystar UAV.
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new to drones

Posted by Danny Scioli on August 2, 2009 at 6:38pm
hello all..im new to drones and autonomous flight..i have a good general knowledge or rc,electrical systems and general electronic circitry....just try to get some input on how to incorperate all of it,what i will need for parts and tools,what i can expect to spend and just some good pics of all the other blogers projects(as long as its not top secret lol) thanks guys (and hopefully girls) for any info...
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Wild Hawk Rtf

Posted by Robert Drone on August 1, 2009 at 2:50pm
What does anyone think of the wild hawk [easystar clone] from exceed?Wild Hawk Picture:

wildhawk.JPG

Link to siteEasyStar Picture:

multiplex-easystar-rtf-47297.jpg

I'm thinking about trying one for now so I can get started flying but I wanted to ask what anyone thought and do some research before I make a decision. Feel free, no, please comment!=]-Rd;)
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Features for next version of Ardupilot

Posted by Peter Seddon on August 1, 2009 at 6:39am
Developing and especially testing hardware and software is never easy and by opening the process to others, solutions can often be identified very quickly and development move on more quickly.I don't know how you went about developing the A/Pilot and I couldn't find any threads about future features so excuse me if I am talking out of turn but I and I am sure others would like to be involved in the process in terms of features for the next version, writing code and testing. Would that be practical?So here is a feature I would like to see:A setup facility for the A/Pilot so that parameters could be configured in an application that then get uploaded to say the EEPROM. I have trouble tweaking about with the source code to make parameter changes (it is too easy to change the wrong parameter).regards Peter
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3D Robotics

Announcing the official DIY Drones Trust Time Trial (T3) Contest

Posted by Chris Anderson on July 31, 2009 at 8:30am

Thanks to the good ideas of Gary Mortimer and others, we're now launching a Trust Time Trial contest. The idea is simple: you set up four waywaypoints, spaced 200m apart, on your own field and time your UAV completing the course. Upload the data in the comments here. Best time on Sept 1 wins (I've got a prize this month--a new FunJet kit). In the future, we'll add complexity and stricter standards to the trial, but this first one is easy: 1) Must complete the pattern as shown above, totally autonomously (go into auto mode before waypoint 1 and exit after you hit waypoint 1 again). The four points are arranged in a square, with 200m on a side (obviously the two diagonal paths are longer). Any aircraft/autopilot allowed. It doesn't matter how close to the waypoints you get, as long as you pass on the outside of them. 2) For this first one, altitude is not graded. 3) Fastest time to hit all points and return to 1 wins (one lap). Must provide GPS track with timestamps and on-board video. (If you don't have/can't afford a small onboard videocamera like the FlyCamOne 2, we'll let it go this time. But in the future: video or it didn't happen!) 4) Must also demonstrate that fun was had. Kids, picnics, silly hats, marching bands, something. GPS tracks are best achieved with an onboard GPS datalogger, like the i-Blue 747 or smaller Sanav ML-7. But if you don't have one or don't want to add the weight, you can just capture the GPS track from your telemetry stream, although you'll have to figure out how to convert it to KML format to export to Google Earth (see below). If your Ground Control System has a built-in map+track function, a screen shot of that is fine, but it should be possible for people to check to confirm that your leg lengths are at least 200m. Evidence data should include these four things: 1) Total time, along with aircraft and autopilot used. A photo of the aircraft would be nice. 2) Screen capture of path exported to Google Earth or an equivalent, annotated with waypoints and where autonomy began and ended. Here's a sample from Dean Goedde (waypoints and autonomy not marked): 3) GPS datalog file, any format 4) Onboard video, embedded from YouTube or Vimeo. [Not absolutely required but requested]
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T3

Paparazzi: The Plug and Play autopilot..?

Posted by Sami Finnila on July 30, 2009 at 1:30pm
I just recently moved over from NXT to Paparazzi and I must admit I'm amazed. Excluding some problems with my radio equipment it was really easy to get flying fully autonomously; just earlier today I got everything plugged in. As the airframe I used one of my EasyGliders. It has AuW of 1,4kg and about 400W brushless setup. With it I'm using a 2.4GHz radio which is plugged to the Paparazzi through the PPM encoder; so no need for a PPM radio. Installing the Paparazzi in place included little soldering (10 wires total including the wires to the datamodem) and cluing all the parts in place.So earlier today I finally got to flying with the PPZ and was hoping for some testing with the so called AUTO1 (i.e. "fly by wire" -mode) but this is what happened; once I had the A/C at a safe altitude I engaged AUTO1 and flew with it some 10 minutes; I worked like a dream right from the start and I hadn't changed a single parameter up to that point (granted, I was using a configuration file that had been made for EasyGlider by another user and I had to make a configuration file for my 2.4GHz radio but still!). Then I engaged AUTO2 and... well... It worked as it's supposed to. I.e. I was flying fully autonomously during my first flight with the Paparazzi. If that's not PnP in the world of RC then what is? (Ok ok.. I had a 35sec flight before this; That flight ended in a crash due to bad 35MHz PCM radio but that's nothing related to the Paparazzi anyways...)Ok, I have to admit that PPZ with all it's features isn't as simple as ArduPilot, for example, but, still, I wouldn't consider it much harder to use once you get the hang of it. Besides once you get into it you'll get to like all the features that already exist in PPZ code repositories; there's, for example, code for a stabilized camera mount, gyros, additional sensor etc. readily available.IMHO the PPZ is nowadays much more of a PnP autopilot than people tend to think. One important thing is that all the needed parts are readily available and assembled. As for the price I paid for my PPZ+PPM encoder+Datamodems about 460$ (CheBuzz PPZ). It's much more than you'd pay for ArduPilot but then again the PPZ is also somewhat more cabable and has much more features although the amount of the features may not suit everyone's taste in terms of conveniency and ease of use.Oh and one more thing; as you may know the PPZ ground station and pretty much all the software made for PPZ is made for Linux, or Ubuntu to be more precise, and this may sound a little sacry BUT Ubuntu these days is probably one of the easiest and intuitive OSes to use AND install. Especially the installing of the Ubuntu is SO much easier than it is for windows, for example; you can even install Ubuntu while you're still using Windows Vista or XP or whatever and you don't need to format your hard drive or any partitions as Ubuntu will make a new partition for you on the fly which isn't possible with Windows and after installing Ubuntu you'll be able to use either operating system as needed. And if you don't want to install Ubuntu onto your laptop that's fine too: a LIVE CD for PPZ has been made which makes it possible to simply burn the CD and put it into your laptop, restart and you're done. As a side note I want to point out that I actually moved over from Windows to Ubuntu permanently once I had first tried the LIVE CD.PS. Now that I reread this post I realised that it really sounds like a 2nd class PPZ advert and there's a reason for it too; IMO many people don't really know how easy it is to use PPZ and this can be seen on many discussions on RC Groups, for example. It seems that especially the Linux part is a very powerfull deterrent for many people. But the fact is that using Linux (Ubuntu) these days is so much easier and convenient than it used to be that in my honest opinnion it's actually much better and easier to use than Windows and in many ways much like Mac.Sami F.
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T3

An example of fully working aerial photography UAV

Posted by Krzysztof Bosak on July 30, 2009 at 8:59am
Note precise track following and functional mission simulator. It helps a lot to confirm on the flying field that everything is set up OK. In the worst case, it will fly to customizable rethome zone and automatically return to takeoff point but the flight would be wasted.

UAV autopilot for aerial photography from Krzysztof Bosak on Vimeo.

kbosak at box43.pl
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