2R robot arm motion planning

[Szmyke]

Hi,

I have a SCARA type robotic arm, a planar manipulator with 2 revolute joints. The arm moves in the horizontal plane.

Now my task is to plan the motion from one point (in Cartesian coords.) to a final (destination) point also given in Cartesian. After the planning, Matlab implementation follows.

Anyone could help how to solve this ?

Tnx. in advance !

Szmyke

[jwatte]

Draw up the diagram of what it looks like. You will find that you can use square-angle triangles and a simple square root to solve this problem. It's known as "two-bone IK" if you want to Google for it.
When the square root goes imaginary, is when the position is not reachable with the configuration of segment lengths you're using.