KDL contains for the moment only generic solvers for kinematic chains. They can be used (with care) for every KDL::Chain.

The idea behind the generic solvers is to have a uniform API. We do this by inheriting from the abstract classes for each type of solver:

• ChainFkSolverPos
• ChainFkSolverVel
• ChainIkSolverVel
• ChainIkSolverPos

A seperate solver has to be created for each chain. At construction time, it will allocate all necessary resources.

A specific type of solver can add some solver-specific functions/parameters to the interface, but still has to use the generic interface for it's main solving purpose.

The forward kinematics use the function JntToCart(...) to calculate the Cartesian space values from the Joint space values. The inverse kinematics use the function CartToJnt(...) to calculate the Joint space values from the Cartesian space values.

Recursive forward kinematic solvers

It recursively adds the poses/velocity of the successive segments, going from the first to the last segment, you can also get intermediate results by giving a Segment number:

ChainFkSolverPos_recursive fksolver(chain1);
JntArray q(chain1.getNrOfJoints);
q=...
Frame F_result;
fksolver.JntToCart(q,F_result,segment_nr);