motoman_IK.world File Reference

Detailed Description

A inverse kinematic (IK) problem with a Motoman SAI20 robot. This robot has 7 degrees of freedom and, thus, by fixing the pose of the end effector the solution set is one-dimensional. Again, this is an example that can be efficiently solved using IK closed form, which are available for the Motoman robot, however, we can also use the general tools in the CuikSuite to address it much slower, though. This is the cost of being general.

This problem can be solved with the following set of commands. Assuming that the motoman_sia20d.world is already generated, we first generate the equations

and then using the cuik solver

  • bin/cuik.c examples/ROSIndustrial/motoman_IK.cuik

This will take very long in a desktop computer (about 2 hours). Fortunately, the cuik process can be easily parallelized. In our cluster the same problem is solved in few minutes.

The solution set can be visualized with

  • scripts/cuikplot3d examples/ROSIndustrial/motoman_IK 7 15 32 0 motoman_IK
  • geomview motoman_IK.gcl

The cuves in the solution set are interrupted due to the joint limits. Note the symmetry in the solution set. This symmetry can be exploited to accelerate the solution process. We are working on this [1].

The solution in the above case includes 12 different on-dimensional curves. These curves can be isolated executing

and the motion along each of the curves can be visualized as

References

Definition in file motoman_IK.world.