Is it possible to apply kinematic decoupling for a 7 DOF 7R manipulator with spherical wrist? If it is possible, can anyone suggest a reference on how to apply this approach with a redundant manipulator with spherical wrist, or explain why it is not possible?

I'm working with Robotic Toolbox (matlab) and the numeric algorithm can find the inverse kinematics solution without a problem if I don't specify the orientation. And I was thinking about solving the problem a second time considering the spherical wrist. Will this approach work?


1 Answer 1


I believe kinematic decoupling used to be the standard procedure for 6 DOF arms. (6R with spherical wrist). Where you would solve the 3 DOF position IK first, then 3 DOF orientation IK.

If you have a spherical wrist, I don't think there is any reason why you can't decouple your problem like this. However, I assume you now have a 4 DOF arm to reach a 3D point. You have 1 redundancy, so your IK will probably give you a number of solutions. So you should do your orientation IK on top of all these...

That being said, i don't believe anyone does it like this anymore. I know at least my kinematics library of choice (OpenRave) can solve 7 DOF IK problems. It does so by discretizing the extra DOF(s).


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