A power-assisted chair with motion-sensing control

A power-assisting device should provide appropriate support for various physical conditions of persons who need supports. Therefore, as a new control technique of a power-assisted chair, a new motion-sensing concept was introduced into a control system for the chair, which is driven by a pneumatic cylinder. A basis of the concept is real-time modification to a desired path. The path is transformed with respect to a time axis according to difference between a standard force pattern and an actual force pattern on a floor. This method makes a sort of new compliance. The control system was implemented for the power-assisted chair. As a result of experiment, real-time adjustment of assist force as the spring characteristics was realized. In addition, this method itself is suitable for pneumatics about safeness.