how to check if robot passes through a singularity

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Hi,

I'm using the excellent KDL solver ( ChainIkSolverPos_LMA specifically ) to solve IK. Something that's biting me is that its actually pretty hard to detect whether the robot is passing a singularity moving from frame_A -> frame_B...

For my application its important to be able to detect this condition. Its not that straightfwd though to compute the nullspace however. What's your advice; as a newcomer to ROS its a little tricky to find out 1) whether I can use my current appraoch to detect passing a singularity 2) any pointers to code in ROS ( moveit? ) that detects passing singularities would be a great help too 3) finally, perhaps its worthwhile to use IKFast for testing this condition? It would imply injecting another dependency, than again, a analytical solver is likely to be more useful detecting passing a singularity.

Any suggestions are much appreciated!