My volunteer managed a cartwheel while wearing the vertigo on her right leg.
Due to the way I attached the vertigo x is now in the z direction so much of the data looks strange at first glance.
My interpretation of the Raw gyro is that the rotational velocity in the x (up) and y(forward) directions was around 200 deg/s. The rotation increases in the second half of the cartwheel as her legs come down. Rotation is a minimum at the top. The z data shows a slight side to side wobble. Interestingly my gymnast has a problem with this simple manoeuvre on beam, landing off centre and often missing the beam. Working to reduce the wobble in the z direction could improve this.
On the Vertigo board, beneath the Mbed you'll see a tiny diagram showing the orientation of the board's frame of reference. Looking at Vertigo with the antenna pointing to the right and the led lights facing up, x-axis is from left to right, y-axis is up and z-axis is into the board. If the x-axis was aligned to your gymnast’s leg you'd expect a full rotation about the z-axis and then some rotation about the other two... but I'm not sure how much. Presumably things move on their way around but then arrive back at where they started. To have the world frame of reference make any sense at all, you might have to ask you gymnast to cartwheel along an east- west or north -south line. Might be very tricky to see what's happening... Great stuff.
Hello Mr Crawford,
ReplyDeleteOn the Vertigo board, beneath the Mbed you'll see a tiny diagram showing the orientation of the board's frame of reference. Looking at Vertigo with the antenna pointing to the right and the led lights facing up, x-axis is from left to right, y-axis is up and z-axis is into the board.
If the x-axis was aligned to your gymnast’s leg you'd expect a full rotation about the z-axis and then some rotation about the other two... but I'm not sure how much. Presumably things move on their way around but then arrive back at where they started.
To have the world frame of reference make any sense at all, you might have to ask you gymnast to cartwheel along an east- west or north -south line. Might be very tricky to see what's happening...
Great stuff.