Gyros for ArduPilot

Hi,I understand the issues about using simple rate gyros with an autopilot - i.e. you can't unless teamed with accelerometers etc - but could one use a head-lock gyro for stabilisation via aileron control ?Max flight time would be about 10 - 15 mins.Simon
E-mail me when people leave their comments –

You need to be a member of diydrones to add comments!

Join diydrones

Comments

  • Interesting comments !
    bGatti's original response reminded me of the occasion I watched a model jet aircraft being expertly flown straight and level down a runway, whilst continuously rolling around the x-axis; not too sure then how you'd use the gps vectors to correct the roll axis gyro.
    The Sparkfun gyro is c $30, add an integrator plus assoc electronics and we're looking at around $70 which compares reasonably with the Co-Pilot IR solution at c $75. However I had in mind an ESky EK2-0704B head lock gyro which is promoted as incorporating drift cancelling. It doesn't claim 'zero drift' but certainly seems, on initial testing, to be pretty stable. I guess I'll just have to try it.
  • Would you (then) use altitude (either gps or baro) to stabilize a pitch gyro? or airspeed?
  • Given that U-Nav doesn't own the idea of a turn-rate wing leveller... I am REALLY shocked that there is no DIY-spawned open source or competing product at a much more reasonable price. It would be the World's simplest test case for a simple Kalman filter in aircraft stabilization: predictions are done by integrating gyro in yaw axis, and the update cycle comes with each GPS update. Simple. $400 for a Pico-N board??? I think NOT! The LISY-AL300 gyro is only around $10, and Sparkfun sells it now.
  • 3D Robotics
    @bGatti: Yes, that's the way the UNAV PicoPilot works. It's okay on stable aircraft but is considered very last-gen technology.
  • I've been thinking about this (Only real experience is connecting the cheap SFE 3 axis Accel to Arduino).

    If we define level flight as flight resulting in forward gps progress, can we not use gps vector to correct the roll axis gyro?
  • 3D Robotics
    Even head-lock gyros drift over time. A heli only needs to hold a vector for a few seconds. A plane needs to know where "down" is for for many minutes.
  • Developer
    http://www.analog.com/en/mems-and-sensors/imems-gyroscopes/products...

    The better Analog Devices gyros have a noise density of 0.05 deg/sec/sqrtHz.
    To be generous, assume your aircraft has a pretty slow response frequency of 15Hz, so you only need to sample your gyro at 30Hz. This means a noise density of about 0.25 deg/sec. You need to integrate the output of your rate sensor to get your rotational position (which is what you are controlling for), which basically means to find the worst-case drift you would just multiply the noise density by the time in seconds. 15 degrees per minute is not a negligible error. Luckily, three-axis accelerometers are getting very inexpensive thanks to hard drive protection mechanisms in laptops, and gyros are thanks to image stabilization in consumer cameras. We may be getting close to a tipping point of affordable inertial stabilization.
This reply was deleted.