GliderIreland - Ireland RC Forum - Flying Model forum in Ireland

Quadcopters / Drones / Helicopters / Rotary wings stuff => Electrics => Topic started by: Ron on October 25, 2010, 19:59:17 PM

Title: Giros
Post by: Ron on October 25, 2010, 19:59:17 PM

Just a simple question (I hope :roll: ), but is it right that giros respond to rotational movement not linear?
So if you had one laying on the bench in front of you and you moved it bodily upwards, or sideways, it would give no response. But if you twisted it, say rotated it around it's vertical axis so it would now be facing a different way on the bench, it would give a response.

Hope all that rambling is clear :oops:

Ron

Title: a simple answer
Post by: rogallo on October 25, 2010, 22:54:27 PM

yes

Title: Giros
Post by: IceWind on October 25, 2010, 22:56:15 PM

Hi Ron,

That is correct.
Like you said a gyroscopic sensor measure the rate of rotation within a particular axis.

The other case would be a job for an accelerometer sensor.

Title: Giros
Post by: Ron on October 26, 2010, 07:56:35 AM

Thanks for the replies.

Next question then is...
Does the giro only respond while it is being turned?
I think this must be the case otherwise it would only stop responding when it returned fully to it's initial position.

Ron.

Title: Giros
Post by: IceWind on October 26, 2010, 11:09:49 AM

Are you refering to a sensor itself or a heli gyro?

The way the sensor itself works is the following.
So these guys usually have a minimun of 3 pins, GND, Vref, Vout.
You feed him with a reference voltage on the Vref pin, let's say 2.5v.
Then when the sensor is stopped it reads like 1.25v in the Vout pin when it's it's turning in one direcftion it outputs >1.25v (ex. 1.40) when it's moving in the oposite direction it outputs <1.25v (ex. 1.10v).
The output represents degrees/second expressed in a voltage difference against the value you read when the sensor is stopped.

Title: Giros
Post by: Ron on October 26, 2010, 12:19:52 PM

Hi Nando,

Thanks for that it explains it all.

So the sensor gives a voltage proportional to the rotation 'speed' (degrees/sec) and the gyro turns this into the required signal to the servo, depending on what sort of heli gyro it is (dampener or heading say).
I guess in the heading hold gyro the internal processor is storing the total angle turned, from the angular speed/sec, and activates the servo until the gyro/model has turned the same distance in the other direction.

Now I understand what's going on  8)
I think  :?:

Thanks again :clap:  :clap:

Ron