ABSTRACT
The aim of locomotion interfaces is to provide realistic walking and running in virtual environments. The design of locomotion interfaces is difficult because of the varied terrain that is to be rendered, and because of the athleticism and diversity of human motions. The familiar cardio devices in a fitness center can be viewed as locomotion interfaces, such as treadmills, stair steppers, and elliptical trainers. These cardio devices can be hooked up to virtual environment displays to provide basic locomotion interfaces. When attempting to implement different locomotion tasks, such as slope walking, navigating uneven terrain, turning, and speed changes, the limitations of ordinary cardio devices become apparent. A number of locomotion interface designs can be understood as the redesign of treadmills and stair steppers to provide added flexibility. The result can be a large, expensive, or complicated device that may also give safety concerns. To date, none of the proposed designs can render the full diversity of human locomotory actions. One is then left to consider tradeoffs as to what aspects of locomotion are the most important, what can be implemented the most conveniently, and what designs are the most cost effective and likely to proliferate. The answer to these concerns is not apparent yet, and researchers continue to investigate alternative designs.
