Tiltrotor support for plane

Development Team
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A quick note on how to configure tilt-quadplanes with vectored yaw.
The two key parameters are:

  • Q_TILT_TYPE=2

  • Q_TILT_YAW_ANGLE=10
    The Q_TILT_TYPE=2 means that you have a tilt rotor that uses motor tilt for yaw (ie. vectored yaw).
    The Q_TILT_YAW_ANGLE is the angle in degrees that the tilt motors are tilted back when at their full up value (as set with SERVOn_MIN or SERVO_n_MAX if the servo is reversed).
    For my convergence I set Q_TILT_YAW_ANGLE=10 as the motors tilt back about 10 degrees when fully up. This parameter allows the code to work out what PWM value to use for the motors to be straight up, and also to work out what range of movement to use in controlling yaw when hovering.
    The only other unique setup for this type of vehicle is you need to tell ArduPilot which servo output controls tilt of the left motor, and which controls tilt of the right motor. The SERVOn_FUNCTION for left motor tilt is 75 and for right motor tilt it is 76.
    So I have:

  • SERVO3_FUNCTION 75

  • SERVO3_MAX 2050

  • SERVO3_MIN 1000

  • SERVO3_REVERSED 0

and

  • SERVO4_FUNCTION 76
  • SERVO4_MAX 2000
  • SERVO4_MIN 950
  • SERVO4_REVERSED 1

that sets up the aircraft so that servo output 3 is the left motor tilt, and servo output 4 is the right motor tilt. The MIN/MAX values and have been adjusted to point the motors straight forward in manual, and so they are centred on being straight up in QSTABILIZE mode. Notice that for the convergence the right motor tilt is reversed (which is why SERVO4_REVERSED is 1).

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