Inverse Kinematics of elbow manipulator

Hi! I’m a student of Bergen university College, and currently working on a CoroBot project, where we’ve added a DOF to the arm.

The arm now consist of three servos, actually four servos controlling the end effector.

I’ve done the forward Kinematics of the arm, resulting in just three links, I exclude the roll and grip servo of the hand tool.
The DH-form is presented under:

Qi |di | ai | @i |
Q0 |d1 | 0 | 90 |
Q1 |0 |a2 | 0 |
Q2 |0 |a3 | 0 |

My problem is the Inverse Kinematics. The subject wich where supposed to contain this procedure on the college, had a really lousy teacher, who never made it through the curriculum, and therefore we never got to learn about the inverse kinematics!

arm: I will try to make an illustration of the arm under…
When I get more time, I will upload some pictures of our project, wich might be in interest for this Forum…

              O---O--
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I REALLY need help with that, on this project. I need the complete procedure on finding the equations for the angles… I will work on it myself, but my bachelor assignement (BIG paper) is supposed to be in next week, and I would really like to add IK to the paper… Though I dont need it to pass…

Here is what you are looking for.

lynxmotion.com/images/html/proj073.htm
lynxmotion.com/images/html/proj057.htm
lynxmotion.com/images/html/proj058.htm

Silver platter not included. :stuck_out_tongue:

Thanks Jim!

But I might miss some obvious pointers here, I have a 3D system, and therefore fail to see the connection with this and my project.

I cant find the equations.

–Louie

The math is in the excel sheet!!!

I see that I’ve made some things unclear in my previous posts.
I will make links to my equations in the next post, so that I might get help with my problem.