A man-machine interface model with improved visibility and reach functions

In order to design ergonomically sound products and workplaces, an improved man-machine interface model was developed as a framework for incorporating multi-factored ergonomic evaluation capabilities into the design. Among various ergonomic knowledge, visibility and reach functions were implemented in the model as two main ergonomic evaluation functions. Three types of visual field were extracted and presented as a visibility function. A human model, a representation of the human body, is regarded as a multi-link system and is kinematically modeled using the Denavit-Hartenberg notation of robotics. By solving the resolved motion method for the kinematic human model, human reach postures were obtained with their motion trajectories along the time history. The man-machine interface model, coupled with visibility and reach functions, can either be used as stand-alone for ergonomic design and evaluation, or, interchangeably used as a front-end to existing CAD systems such as AutoCAD and I-DEAS. The model is expected to be used as a valuable tool when designing products and workplaces right from the design stage.