XY movement with camming

I will have to make manipulator with servomotors, that moves vertical and horizontal (XY plane).
I want the manipulator first to go up strictly along the Y-axis, and at a certain position going along both X- and Y-axis. The resulting movement of this part should be a perfect quarter circle.
Afterwards the movement should continue strictly along the X-axis.
I should want to do this by camming both axes to a virtual master.
Only I don't know to construct my cams to create the quarter circle.
Anyone has experience on this?

It's a pity, that we miss our math lessons. Did you try to search for "circle equation"?

One hint is that your x^2+y^2 should always equal the radius, which is constant that you know. Of course this is valid if your center of the xy system matches with the center of the circle.

There are 3 basic parts to this motion profile. It should be possible to enter x and y as a function of the virtual master. That should be easy. x will be constant while y is ramping up. The tricky part is that the virtual axis must ramp up at the beginning of each part of the motion profile and ramp down at the end so the x and y axis will start from 0 speed at the beginning and slow to 0 speed at the end.

Use the y=r*sin(k*t) and x=r*cos(k*t) function to make the arc.

You should be able to do all this in an Excel spread sheet.

calculate every 10 msec where both motors should be, then make on your virtual shaft and set the positions. please take care not to move too fast, as the speed is limited.

shooter said:

calculate every 10 msec where both motors should be, then make on your virtual shaft and set the positions. please take care not to move too fast, as the speed is limited.

Click to expand...

A little calculus takes care of that.
Here are examples of 1,2 and 3 dimensional examples of limiting the speed.
Basically the master index must slow down if the feed speed is too high. Usually the feed speed limitation is only a two dimensional calculation. In free space you are only limited by the speed of each axis or motor.
http://deltamotion.com/peter/Maxima/feedspeed.html

In aand74's he needs to vary the speed of the index at the end points and if a feed speed limitation exist he needs to use the techniques I show in my link.