Optimization-based inverse kinematics of articulated linkages

Articulated linkages appear in many fields, among them, robotics, human modeling, and mechanism design. The inverse kinematics (IK) of articulated linkages forms the basic problem to solve in various scenarios. This chapter presents an optimization-based approach for IK of a specific articulated linkage, the human model. The problem is formulated as a single-objective optimization (SOO) problem with a single performance measure or as a multi-objectiveoptimization (MOO) problem with multiple combined performance measures. A human performance measure is a physics-based metric, such as delta potential energy, joint displacement, joint torque, or discomfort, and serves as an objective function (cost function) in an optimization formulation. The implementation of the presented approach is shown for three models: a 4- degree-of-freedom (DOF) finger model, 21-DOF torso-right hand model, and 31-DOF torso-both hands model. Preliminary validation using a motion capture system demonstrates the accuracy of the proposed method.