Setting up the tilt angle.

Discussion in 'Radian' started by André Cousin, Nov 16, 2012.

  1. André Cousin

    André Cousin New Member

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    I put a potentiometer to adjust my tilt angle and when I make a move with the pot, angle increase or decrease but the movement don't stop until I go back with my pot.
    Is this normal?

    I wish to adjust my angle by giving some value to my pot, but with the pot staying in place.
    Is that possible?
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Nisouck:

    If you have put a variable potentiometer out on the Radian sensor controlled servo, it will not work as you intended -- that's why when you convert to the Radians you substitute a fixed pair of resistors.

    Let me know if that doesn't answer your question -- I may have misunderstood what you're asking.

    Andy.
     
  3. André Cousin

    André Cousin New Member

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    Hi Andy,
    Thanks to reply.
    What I do is to connect a receiver output (that is commanded with a pot) to Radian tilt input 1.

    I do that to change my tilt angle as I move the pot.
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Nisouk:
    OK, so the pot is on your transmitter and you have assigned it to a particular channel. Thanks for clarifying that.

    Tell me exactly what connections you have to the Radian tilt sensor, how you are providing power to the Radian sensor and then can you take a screen shot of the Radian software when you have connected it up to the Radian sensors and done a Read and with the Radian system in Stabilized Slew mode -- that way I can see how you have the parameters set. I need to see both the diagnostic window and the configuration window.

    Thanks
    Andy.
     
  5. André Cousin

    André Cousin New Member

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    Hi Andy,
    Tilt Radian connections:
    1: Receiver to angle change (Via pot) without red wire.
    2:
    3: Go to Radian Roll
    4:Tilt servo

    Roll Radian connections:
    1: External 6V supply
    2:
    3: Go to Tilt
    4: Roll servo

    And the screen shot showing software after a Tilt read.
    Thanks.
    Nisouck
     

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  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Nisouck:
    Thanks for the good description. Could you try changing the setup to this and let me know if it changes anything:

    Tilt Radian connections:
    1: Receiver to angle change (Via pot) without red wire.
    2:
    3: Go to Radian Roll (you do not need to loop back to the Tilt servo -- this is the end of the "chain").
    4:Tilt servo

    Roll Radian connections:
    1: External 6V supply (just to avoid the possibility of electrical noise on an input port).
    2: External 6V supply
    3: Go to Tilt
    4: Roll servo

    I'm concerned about these things:
    1. Feeding in power on a Radian port 1 might cause electrical noise to come in on the slew control input.
    2. By having the Roll Radian connected to the Tilt Radian and a "loop back" from Tilt to Roll, I wonder whether you have created a feedback loop?
    3. I notie that you have only a 2% deadband - is there a reason for that?

    Let me know what happens when you change things as above.
    Andy.
     
  7. André Cousin

    André Cousin New Member

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    Hi,
    I get the same problem if I supply power to port 2.

    But I don't have a loop back between roll and tilt; just a connection from port 3 tilt to port 3 roll.
    Than if I remove this link, I don't have power to my tilt.

    For the deadband, I don't really care of that, I start setup; not yet finished it.
    Thanks for help.
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Nisouck:
    But port 3 is an output from one Radian sensor to the input on another Radian sensor -- so port 3 on roll should go to port 1 on roll. You have port 3 on roll going to port 3 on tilt.

    The roll sensor is expecting to see it's input on port 1 -- but you only have +6 input (and the possibility of noise on the signal input pin there).

    See the pinout diagram on alongside image 1 in the Radian documentation.
    I should have caught that problem earlier -- sorry.

    Using your original wiring, the best I can come up with is:
    Tilt Radian:
    1: Receiver to angle change (Via pot) without red wire.
    2: Connected to port 3 on the Roll Servo (ground and power only)
    3: Go to Radian Roll port 1.
    4:Tilt servo

    Roll Radian connections:
    1: External 6V supply Input from Tilt radian port 3.
    2: External 6V supply
    3: Go to Tilt port 2 to provide power to the Tilt Radian and servo (ground and power only).
    4: Roll servo

    The above is way too tangled so a better way would be:

    Roll Radian:
    1: Receiver to angle change (signal pin), +6 volts on red pin, ground pin connected to both receiver ground and +6 v's ground wire.
    2:
    3: To port 1 on tilt Radian.
    4: To roll servo.

    Tilt Radian
    1: From port 1 on Roll Radian.
    2:
    3:
    4:To tilt servo.

    Hope this helps. Do you see what I mean by the output of the roll Radian (port 3) connecting to the tilt Radian (port 1)?
    Andy.
     
  9. André Cousin

    André Cousin New Member

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    Hi Andy,

    I am really sorry all of that dont change some thing. Always the same: angle change until I go back with the pot.

    To simplifly, I only connect the Tilt Radian as:
    1 - Input signal from receiver pot.
    2 or 3 - Suppy 6 V. (changing channel for supply voltage does not change the result).
    4 - servo

    I made the same on the roll radian, it react exactly the same ....
    I made a 2 mode switch, nothing change.

    What I may say more:
    1- I use PWM mode from my receiver (one output for one fonction).
    2- As I move the pot, on software, I can see "Current Angle Demand" increasing until I go back with the pot even I put a verry small demand in angle change.

    Hope you can help.
    Regards.
    André
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi André

    I think I now understand what you were originally asking. Let me rewrite your original question just to be sure:

    Question: When I move a control stick (or a rotary control) on my transmitter to control, for example, the tilt servo, if I move the stick, the tilt servo keeps moving until I re-center the stick. Is this normal behavior?

    Can you confirm that this is your question and that I have understood it correctly?

    If that is indeed your question, then the answer is yes, this is normal behavior.

    The Radian sensor/servo uses the amount of stick deflection to control how fast the tilt servo moves, not how far it moves. In other words it is a tilt slew rate control not like the MK flight control board when it is used on the gimbal which is a positional control -- the amount of deflection controlled the tilt position (Note: I am going from memory on this -- perhaps someone who has a better memory or who is still using the FC board on the gimbal can confirm this?)

    Hope this helps
    Andy.
     
  11. André Cousin

    André Cousin New Member

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    Hi Andy,

    Yes, you are right, that unfortunatly his normal behavior.

    Not a too big problem, but I think that's not the good option.

    Many thanks for the help.
    Regards.
    André.

    PS: Radian is a very (probably the best) product form now! :)
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi André
    Aha! My apologies for misunderstanding your original question.
    Glad you like using the Radians.

    Et peut-être la prochaine fois que je dois vous répondre en français et en anglais pour le rendre plus facile pour vous.

    Regards
    Andy.
     
  13. André Cousin

    André Cousin New Member

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    Hi Andy,
    Again, thanks for all.

    Could I say that, in my point of vue, this is not the best way to make some slew angle.
    I think the most natural way is like we do with the elevator of a airplane: you get some angle proportional to the stick angle.
    That could be a MAJOR update improvement. May be you may make the 2 possibilities by choice.
    Regards.
    NB: Thanks for French but I need to improve my English.
     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi André
    It's a personal preference -- I do tend to agree with you though. I prefer the "positional control" as you describe -- all the other flight controls are positional -- for the deflection from the null position of the control stick is proportional to the amount of the deflection of the aircraft control.

    I understand!
    Andy.
     

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