Inverse Kinematics implementation

[bensisko]

Hi all.

I'm a complete beginner with LabView and I have been practicing forward kinematics with the help of a tutorial I found. It's been a learning curve but I've managed to understand a few things.

However, I have not been able to implement an inverse kinematics vi.

I've been trying to replicate this tutorial but I have been unsuccessful so far.

I'm working with a SCARA serial arm.

I would really appreciate some guidance on this issue.

[Lysandros]

In order to control the serial manipulator you will probably need logic running in the background, which might involve matrix algebra. Find out what the mathematic equations you need to execute.

If you want to implement it with a real robot arm, then you may need sensors, actuators and hardware in order to acquire and general signals.

[bensisko]

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@Lysandros wrote:

In order to control the serial manipulator you will probably need logic running in the background, which might involve matrix algebra. Find out what the mathematic equations you need to execute.

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Thanks for your response. I can't say I understand what you mean but I managed to get make some progress with my vi. When you referred to matrix algebra, did you mean a "transform from translation" matrix from the robotics plugin? I really am a beginner so please excuse me if I am wrong.

Please see my updated vi attached. When I run it I get the following error:

NI_Kinematics.lvlib:Inverse Kinematics (Point).vi->Inverse Kinematics Attempt-1.vi

LabView cannot converge to solution in the number of steps you have specified. Make sure the serial arm can achieve the transform you desire.

Can you help me resolve that error?

[MarcDub]

I have developed in the past a VI to calculate the inverse kinematics of a Scara robot. I did not want to use the LabVIEW robotic module so I used the equations from this reference. I then incorporated this VI into another VI to test forward and inverse kinematics for a Scara robot.

Below is the block diagram of the inverse kinematics VI. Notice that there are 2 possible solutions for any X-Y input value so you have to say if you want the solution for the positive or negative value of angle 2 (through boolean "Positive a2?"). 

I incorporated this VI within another VI that draws a Scara robot in a 3D picture control that you can move and modify in real-time. The goal was to test the forward and inverse kinematics. Below is the front panel of that VI. I have somewhat cleaned up the code and uploaded it with this post. I hope that overall it would help you even with the robotic module.