Inverse kinematics: a review of existing techniques and introduction of a new fast iterative solver

Inverse Kinematics (IK) is defined as the problem of determining a set of appropriate joint configurations for which the end effectors move to desired positions as smoothly, rapidly, and as accurately as possible. During the last decades, several methods and techniques, sophisticated or heuristic, have been presented to produce fast and realistic solutions to the IK problem. However, most of the currently available methods suffer from high computational cost and production of unrealistic poses. This report reviews and compares the most popular IK methods regarding reliability, computational cost and conversion criteria, with a novel heuristic and iterative method, called Forward And Backward Reaching Inverse Kinematics (FABRIK). FABRIK avoids the use of rotational angles or matrices, and instead finds each joint position via locating a point on a line. Thus, it converges in fewer iterations, has low computational cost and produces realistic poses. Constraints can easily be incorporated within the FABRIK methodology and multiple chains with multiple end effectors are also easily supported. i