[tktyler117]

Hi, I am trying to make a forward kinematic solver using the DH parameters from RoboDK. I was able to get the modified DH parameters from the robot's parameters, and I tried using the transformation matrices from Wikipedia for the modified DH parameters to solve for the transformation from the base to the flange, but I cannot get my solver to match RoboDK, and I'm not sure why. Shouldn't I be able to pair the parameters with the transformation matrices attached to get a working solver?

To provide more information, I solve the transformation between each joint using the transformation matrix in the image attached, then I multiply the transformation matrices for each joint to get from the base to the flange. I don't have any additional tools on the robot, so I don't have any additional transformations to get to the TCP.

Thank you!

[Albert]

You should be able to match the data by using the dhm function in the RoboDK API.

Calling dhm(rx,tx,tz,rz) is the same as using rotx(rx)*transl(tx,0,tz)*rotz(rz).

You can find more information here:
https://robodk.com/doc/en/PythonAPI/robo...bomath.dhm

How are you implementing the math?

[tktyler117]

Ok,  I will look into that. Thank you! 

I am calculating the transformation between each joint using the modified DH transformation matrix I attached originally. Once I have the matrix for the transformation between each joint, I multiply them in the order shown in the new attachment to get the transformation from the base to the flange. I have double checked that I am using the correct transformation matrix multiple times, and it is definitely the modified version. I am trying to solve it without any tools on the robot first, so I am not doing any additional transformations beyond the flange.