Hi

 

Could I please build on your vast knowledge.. I have a thermo setup with telemetry ect. When in fly_by_wire mode and trying to check the gains settings. Movement to the right left or pitch up or down has very little effect on the attitude of the plane itself... Maybe a 2 to 3 degree change in roll and pitch. On the GCS however the reported attitude is the max angles +- 45 degrees and 10-15 on the pitch. How could i solve the problem of the thermopiles being so over sensitive. I am using 2 FMA themopiles.

 

Thanks

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  • Hi jason and chris... Thanks for the prompt response . I do believe it it is beta 5.2. I will test the z sensor tomorrow after all the solder mods are done. I really think adding a bit of rudder mix should work wonders!
  • Hi graham... It seams that not using the z sensor solves the problem. Flew the plane with z set to no z sensor and just turned the plane to calibrate.. After that I had my first semi decent flight.. Actually banked more than 20 degrees.. Adding just a bit of rudder manually really made it turn nicely... Btw- I fly in potchefstroom
  • Moderator
    Cronselaar, I don't know if you've sorted this out with the newer version of the software but I've noticed a similar thing using v.2.6.2. This problem was touched on here: http://diydrones.com/xn/detail/705844:Comment:172749

    I've changed my "#define HEAD_MAX" to 7000 to get FLY_BY_WIRE mode to bank the aircraft correctly, now I get a bank angle of around 10 deg.

    This may no longer be an issue with v2.7.x but I'm waiting for a final version before trying it.

    btw where are you flying?
  • Developer
    IR_MAX is always the culprit when these things aren't performing.

    Add these two prints(below) to your code to verify things. Notice that the plane MUST be level for you to read the Z sensor. At ground start the window for what is considered level is very narrow - maybe 2-3 degrees. The best thing to do is hold the plane level before you take off and verify the stabilization is working correctly. You will see the deflection of the ailerons slow as the correct calibration is dialed in. If they move too rapidly, you aren't calibrated.

    If you continue to run into trouble, consider upping your window from 1000 to 1500 or even 2000. This will lower the accuracy a bit but make it easier to calibrate.

    for example: if(abs(roll_sensor) <= 1500)

    void read_z_sensor(void){
    Serial.print("ir_max: ");
    Serial.println(ir_max,DEC);

    //Checks if the roll is less than 10 degrees to read z sensor
    if(abs(roll_sensor) <= 1000){
    analog2 = ((float)analogRead(2) * 0.10) + ((float)analog2 * .90);
    ir_max = abs(511 - analog2) * IR_MAX_FIX;
    ir_max = constrain(ir_max, 40, 600);
    }
    }
    Jason
  • I am using a Z-sensor... That is the reason for the two FMA sensors... Here's a couple of pics during testing this weekend. Again I can not get the thermopiles to function correctly. This time something else showed as well. If i bank to steep the plane won't level itself out and tries to do rolls and heads straight to the ground.. This makes for exciting flying! I do have telemetry data and if i really need to add a video i can do that as well. Please have a look at the pic of the plane... look at the Z-sensor placement and do comment. As for the one on the wing-I'm designing a stand for the 3-d printer as well. I believe the 60degrees blinded by the wing could be a problem.
    Thanks
    Gerrit

    APflight_2010_07_24_17_03_19.kml

    ArduPilot_DataLog_2010_07_24_16_44_56.txt

    APflight_2010_07_24_17_34_20.kml

  • 3D Robotics
    What ground calibration procedure are you going through? (or are you using a Z sensor?)

    If you're using a Z, it's designed to self-calibrate in the air in about a minute. If you're not using a Z, you need to do a vertical rotation so each XY window points at the sky at least once.
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