Approximate Inverse Kinematics Using a Database

The goal of this project was to create an approximate inverse kinematics solver that generates solutions for manipulators that have less degrees of freedom (DOF) than the space in which their end-effectors move. In such situations, it is improbable that there is an exact solution to an arbitrary 6-DOF pose. Even though one cannot find an exact solution, one can often find an approximate solution. In this paper, we propose a database approach for finding the approximate inverse kinematics solution. The motivating example for this project is the iRobot PackBot. This robot only has a 5-DOF arm, but its end-effector operates in a 6-DOF task-space. Without an approximate inverse kinematics solver, it would be difficult to interface with existing algorithms, such as grasping algorithms. This approach enables interaction with algorithms that assume that 6-DOF poses can be reached.