Hi all,

Sorry for the late reply. I have been busy

I will try to answer all the questions.

question 1: Do you use positional control or velocity control ?

I use positional control. But the data that is used makes sure that all the movements are smooth. You can check the data (squaredat) here:

http://cid-976b52dad42d0a1e.skydrive.li ... otics?uc=1
I also put some comments there. This reads more easily. As you see there are enough datapoints (+-600 points). So there is no way that there is loss of accuracy in the software. Like I said, the mathematics are correct.

I also put an excel file "Cubic Segments" to show this principle of smoothness. This smoothness is based on a differential equation of the second degree. So you have to give 4 conditions: the start and end angle. And the speed of this start and end angle. This macro calculates a smooth path between those points according to the 4 conditions. The whole software uses this principle.

question 2: Do you use matrix calculations ?

Yes, because the DH transformations are matrices. The forward tranformations are just DH matrices multiplied after each other. All the datapoints are also stored in matrices. I programmed this robot with Visual Basic 6. I made a class matrix. With these matrices I can do addition, multiplication, determinant and inverse calculations.

question 3: how are the IK calculated ?

The IK is done like Andy said. I use DH transformation to do the forward kinematics.

The inverse kinematics are done with the formula's in the PDF file. I derived them myself. You can look at these as an exercise

The last page of the PDF file is what this is all about.

I have put them for those who are interested to program it yourself.

You can just use these formula's in your application

The forward kinematics are the easy part.

This is just matrix multiplication. The real stuff is in the inverse kinematics

. Because here you have multiple solutions of the robot configuration for each point in space...

But all this, is a lot to explain. I would rather refer to the following book where I learned all this stuff.

Robotics: Basic Analysis and Design

William A. Wolovich

Brown University

ISBN: 0-03-006119-9

This is really a great book because it starts from zero. Each chapter has some

exercises.

So this was it. I hoped helping you all out.

Let me know if there are more questions