Flight tests with ArduPilot in EasyGlider Pro

I posted an earlier blog with pictures on how I placed the avionics in an EasyGlider Pro for autonomous flight. I found out that was the easy part! Now I’m performing flight tests to hone in on the code mods for stable flight ( as Jordi states, the latest code is optimized for the EasyStar). My method has been:Fly and observe performance in autonomous mode – record observations – make code modifications on laptop – remove GPS and upload code – replace GPS – fly again. Laborious but also fun since physical computing yields immediate effects that you get to see.I’ve attached a table I made in Excel to organize my iterations and keep me on track. Maybe this will help others in the same situation. One mistake I made was getting in a hurry to go fly. I could have found out about the reversed servo throws and IR sensor placement by just walking the plane around on the ground and changing its attitude by hand. This would have avoided the “death spirals” I experienced on that first day of flying!Bryan

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  • Hi, I am new here and hope if any one can help me out with the Fly_By_Wire in manual mode.
    My Fly-by-wire is not working as well in manual mode but i works in WP and RTL mode. I have change FLY_BY_WIRE_GAIN_ROLL & Pitch @16 or 8 or even 40, never works. No idea how to make it work. I check the XYZ sensors by using sensortest.pde and it seems XY,Z sensor all got good reading. My set up as following
    Sketch: I_CAN_FLY; Hardware: ATMega328-based ArduPilot with Shield expension board; Sensor: DIYDrome XY,Z sensor; software: Arduino IDE 015; GPS: EM406;
    Easystar Header file change the following, and others remain unchanged.
    //1-4 #define REVERSE_ROLL 1; //1-5#define REVERSE_PITCH 1 ;//1-7 #define GPS_PROTOCOL 1 (=SIRF)
    //2-1#define FLY_BY_WIRE_GAIN_ROLL 8; //2-2#define FLY_BY_WIRE_GAIN_PITCH 8;
    Has any one had this problem before and than solve it out. Could anyone know how to adjust it??
  • @ Chris

    Quick question, should the sensors report in fly-by-wire mode, so if you put your hand over them will it turn to opposite deflection for the control surface similar to the way FMA copilot works standalone. So far, when I try to use it, whether @ 16 or 8 it doesn't show any operation on the ground test. In the air, it doesn't do anything, so is there a way to test the sensors are working on the ground. If there is, that would be awesome...
  • 2 hours until the test flight. Bryan, I will update you post my flight. All systems are a go, 6:30pm PST I will do 5 flights with the new code, it looks like jordi modified the buffer for GPS from 100 to 200. Hope that does it, haven't looked for other changes, but I am ready to go....

    For sure when Jordi has the Ubloxs, Im switching, especially if it gives more accuracy to the autopilot which seems to be the case.

    Keep your fingers crossed, its a scorching 98 degrees here today, so I will be cooking while doing this test... :)
  • 3D Robotics

    To get fly-by-wire to work, change the gain settings in the config file to 8. Our default of 16 was too high.
  • Hi guys,
    For the moment, I'll stay grounded untill the Ardupilot code is fixed. Peter M. has been putting in a lot of flight time trying to diagnose what the problem is and he is flying the recommended plane. Between Peter's flight tests and Jordi's programming skills I'm sure there will be a new code revision that will work fine.
    Yes, I'm using a Y connector for the ailerons and the rudder is fixed. I've used the FMA Copilot on an electric trainer that also had just just one aileron servo like you described and it did work great. Unfortunately, I 've not gotten the "fly by wire" mode to work in the last two Ardupilot codes so it's tuff to compare. Overall, I think the EasyGlider is a good performer and the Elapor foam is easy to work with but there isn't much room in the stock cockpit.
  • Bryan, any update on the EZglider testing? I'm about to head down that path myself.

    Are you using a Y connector for the aileron servos? The reason I ask is that I tried putting an FMA on just one aileron servo and to me it worked better than it did when using a Y connector. Not what I expected....
  • Moderator
    Bryan, well done on having the diligence to record the parameter changes and their apparent effects! It really helps those of us in the same boat trying to get a non-standard airframe to navigate correctly - some of my experiences blogged here: http://diydrones.com/profiles/blogs/failures-and-sucesses

    keep it up...:-)
  • 3D Robotics

    Yes, that's why we added the airspeed/throttle loop. We were unable to get consistent results with the EasyStar in wind. A powered glider, because it's so affected by wind, is actually one of the hardest planes to use for a UAV. (AttoPilot actually recommends against them). But they're easy for beginners to fly, and the EZ is cheap and indestructable, so we picked it anyway. The FunJet can fly well autonomously in the wind without an airspeed sensor, but the EZ (and other powered gliders, such as yours) needs one.
  • Latest flight tests-- I'm realizing the importance of throttle management so it sounds like the Ardupilot shield with the pressure sensor will be a big help. Pretty strange how the weather appears to have such a strong effect on performance.

  • OK, well when I have my EasyGlider I'll have a good go at the settings...
    .... or maybe 2.2 will be out by then. :)
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