XYZ

Jul 29, 2006 11 Replies

Hi,



I guess it's vaguely related to robotics....



When you have four axis of movement, what's the fourth? It goes X, Y, then Z, but what's next, and after that?



Michael


Generally the fourth is considered time. Let's say you plot the motion of a robot helicopter. It can be at one place in space (x1,y1,z1) at one time, and another place in space (x2,y2,z2) at another time. So to full describe where the helicopter was, you can describe it by x(i), y(i), z(i), t(i). Until you get into special relativity i=t.

Well at the moment, I'm writing a program that takes input from a joystick and it says R is the fourth except I've never heard of that...

Michael

It believe pitch and yaw (rotation) is the next axis of movement although the fourth dimension is time.

X, Y, then

Michael - do you mean 4 degrees of freedom, perhaps ?

If so, it could be that your manual is referring to rotation of the grippers (as in wrist) if you were talking about a robotic arm. I'm sure the other pros on here can help verify this. If you're talking about something else, say a spacecraft, it could mean rotation about any of the 3 axis.

In the mean time, this site might be of some help:

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found it by doing a Google search on "4 DOF robotics".

Hope that helps! JCDeen

I just re-read your post and I would bet money that "R" means "rotation". Some joysticks allow you to twist it as a 4th means of control, I believe. Try Googling on "4 DOF joystick".

Hope that helps more than my other post! JCD

In CNC machines, the 4th axis (A) is generally the first rotary table.

No because the controller I'm using is similar to the dual shock playstation one with two joysticks, and in the code the first 3 are XYZ and the next ones are RUV, and to me it seems a bit of a random place to start the next 'set'.

Actually talk about the cnc rotary table reminded me of this pic:

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Michael

I, J and K - used on industrial robots, basically yaw, pich and rotation. The fourth axes the I, on a milling machine is the rotary table where helical interpolation can be cut. J and K axes are used for complex curves and used on most cartesian coordinate measuring devices holding the touch probe and infrared sensors.

from a

the next

I see. In the future it would help to give all that info up front to prevent a few wild goose chases. Good luck !

yay, the answer I think he wanted in the first palce! :)

also Theta and Phi also tend to represent angular postions

dan

Wayne Lundberg wrote:

Well I figured that as the joystick followed the norm by starting out with XYZ it would carry on after that like other devices.

Michael

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