The Iowa interactive digital-human virtual environment

Proper assessment of human reach posture is one of the essential functions for workspace design and evaluation in a CAD system with a built-in human model. Most existing models have used heuristic methods, which provide only the range of feasible human reaching postures, which may or may not include naturalistic reach posture. We present a multi-objective-optimization (MOO)-based approach for predicting realistic reach postures of digital humans, one based on our belief that humans assume different reach postures depending on different cost functions, i.e., multi-objective functions. In this work, the number of degrees of freedom (DOF) associated with the model is unlimited, and ranges of motion of joints are considered. The problem is formulated as MOO and single-objective optimization (SOO) algorithms where one or all cost functions (joint displacement, energy, effort, etc.) are considered as objective functions that drive the model to a solution set. A real-time simulation of the digital human's motion is applied in the IOWA digital-human virtual environment.