Is it possible to mimic a joint in a robotic manipulator?

I want to create a 7-axis robot whose sixth joint needs to mimic its fifth joint. The magnitude of the joint angle of the sixth joint must always be equal to the joint angle of the fifth joint but opposite in direction. I did not find any constarint that can be added to rigidJoint. I tried to import the URDF file of the robot in which one can define a joint such as follows:

<mimic joint="jointX" multiplier="-1.0" offset="0"/>

However, this property is not reflected when imported in MATLAB and solved by inverse kinematics.

Is there a constraint which I can add to generalizedInverseKinematics solver which will only provide configurations which obey the above condition? Or is there any other way to achieve this?

Answer 1

[Karsh Tharyani]

Hi SNS,

This is currently not supported. I have forwarded your request to the development team to add support for a mimic joint for a future release of MATLAB.

Best,

Kars