Help to use Inverse Kinematics VI and Set Dynamics VI in Labview Robotics

[epgodoy]

Hi,

I was wondering if somebody can help me with the use of the Inverse Kinematics VI and the Set Dynamics VI available in the Robotics Module of the Labview 2009. I have changed the PUMA560 examples according to the specifications of my AL5D robot arm.

For the Inverse Kinematics VI, what are the required information (input) to use it?

Because when I tried to use it using the (x,y,z) as inputs, this error appears "Error -310040 Labview Robotics (HEX 0xFFFB44E8)"

For the Set Dynamics VI, what are the units used for the definition of the elements (mass, motor inertia, friction, inertia matrix)? For example the mass is in kg, oz, etc? Are they all in metric standard?

To define the mass of each link, how can I deal with the motors mass? Do i need to sum the motors mass with the mass of the links?

What about the center of gravity definition of each link? Are the (x,y,z) coordinates according to the world frame coordinate system?

Thanks,

Eduardo

[muks]

From the error code

−310040 LabVIEW cannot converge to a solution in the number of steps you specified. Make sure that the serial arm can achieve the transform you desire.

Basics of Robot Kinematics

[epgodoy]

Dear Muks,

I know about it but i think that this is not the problem.

Because I have developed a VI with the mathematical equations of the inverse kinematics (IK) for my arm and it is working fine.

But when I use the IK VI from Labview, I get this error.

I would like to have sure which kind of information i need to input for the Labview IK VI to it works.

For example the x,y,z position and the end effector orientation (The example provided with the Robotics module did not clarify my doubts).

And what about my other questions about the Dynamics? Can you give me some help?

Thanks for the reply.

Eduardo

[S_Kamath]

For the inverse kinematics you do not need to specify the dynamic parameters. If you are planning to use the dynamic functions then the units are metric standard.

For troubleshooting IK problems the top possibilities are:

1) Mistakes in specifying DH parameters. Look at the visualization and check it at different joint values to ensure it reflects reality. You can also check the forward kinematic results against your custom IK solver's results.

2) Joint position unacheivable. One common mistake in this area is that by default the IK tries to converge on position and orientation specified in the homogenous transform input. For a arm with less than 6dof you may not be able to achieve all of x,y,z,theta,phi,psi. You can specify a mask to ignore some of the variables.

[S_Kamath]

You may also want to look at this thread regarding the same error:

http://forums.ni.com/t5/LabVIEW/Unexpected-310040-error-could-not-converge-in-LabVIEW-for/m-p/115349...