The development of ergonomics design criteria for powered human movement systems

Abstract

This research developed from a concept for a powered exoskeletal system for manipulating a person's posture to provide them with physical sensations as though taking part in an activity in which they otherwise would not be able to participate. The aim for this research was to develop a set of criteria relating to this physical manipulation, which could be used, in conjunction with visual and audio stimuli, to govern the design of a commercial personal entertainment simulator for use by members of the public. Investigations revealed that there is currently no existing system comparable to this proposed simulator. Therefore, various fields were researched, including robotics, physiotherapy, virtual reality, haptics and existing simulators; with a view to combining elements of these fields for the development of a manipulation system appropriate to public entertainment use. A survey was conducted on members of the public to investigate their experiences of sports, theme park rides and virtual reality; their personalities; and their opinions of the proposed simulator. This survey indicated that the likely users of such a system would be sensation-seeking, physically active people. The activities which generated the most interest were those which were hazardous, difficult, or required long distance travel. To be consistent with these findings, practical trials were undertaken using the sport of skiing as the context for conducting practical investigations into postural manipulation. Existing and original studies of the movements involved in skiing revealed the complexity of this activity, and the variety of techniques employed by different skiers. These findings, combined with the survey data and earlier investigations, led to the development of a versatile prototype system which could accommodate this variability and impose customised skiing movements on volunteers. Volunteer trials using this prototype demonstrated that members of the public were willing to have their postures controlled by external forces, and although some participants were apprehensive at first, they all reported the experience to be enjoyable. Tests with different applied movements showed that users were comfortable with manipulations at speeds and accelerations up to and exceeding those employed in skiing for real. The principal criteria concluded from these trials were that it is possible to safely and comfortably manipulate human postures through external technology, and that this external control can be used to provide an enjoyable and exhilarating entertainment experience