A Modular Architecture for Inverse Robot Kinematics

The development of a modular architecture for general purpose inverse robot kinematics is the objective of this paper. We synthesize kinematic modules for the robot arm and wrist and develop computational blocks to describe their respective functions. We then present an analytical framework that defines the inverse kinematic problem in terms of the proper coordination of the kinematic modules to accomplish the desired robot task. In this general-purpose framework, the inverse kinematics problem is always solvable in the feasible regions of the robot workspace, irrespective of whether the solution is analytically tractable. The modular architecture is based upon a nonlinear equation solver for which the Banach Fixed-Point Theorem provides the theoretical basis. The proposed framework allows for the mathematical definition of the region in the robot workspace where convergence to the correct solution is guaranteed; is insensitive to the initial estimates; and provides for the computation of multiple solutions.