Novel Design of an Active Transfemoral Prosthesis with Intellectual-Synergetic Control System

摘要

This article presents a new design of an active transfemoral prosthesis with an artificial knee joint controlled by a system based on an intellectually-synergetic concept. One of the main criteria used in the prosthesis design process was to achieve the maximum biological similarity of this device with aim to ensure optimal conditions contributing to the user's natural walking. Artificial knee joint, designed on the basis of a polycentric hinged mechanism with intersecting links, provides such conditions at the design level, and a three-level hierarchical control system, built on the basis of an intellectual-synergetic control concept, - at the control level. To recognize user's intentions, the intelligent subsystem uses algorithms of comparing graphic images of walking phases, by the method of Hu's invariant moments estimating. After that, in the synergetic subsystem movements of elements of the prosthetic device are planned in accordance with synergetic quality criteria. All algorithms used in the control system are easily adjustable, depending on what artificial foot is used in the prosthesis: active, semi-active or passive (mechanical). Mathematical modeling of the prosthesis work indicates that the nature of its functioning corresponds to the quality criteria adopted during designing. The key subsystems' work of the prosthesis prototype, made on the basis of digital model, will be investigated in the near future with a specialized test bench.