Recently, the introduction of mechatronic drives to lower limb prosthetics is subject to rehabilitation research, as it allows to support users by introducing power to locomotion. Prostheses can be interpreted as semi-autonoumus mobile robotic systems and heir developers are thus confronted with various technical issues ranging from energy efficiency and storage to nonlinear control of adaptive mechanics. Yet, the users point of view, which shows to be crucial for prosthetic function, is not considered in design sufficiently. Hence, new design methodologies integrating human factors and thus considering psychological issues are required. As a technical realization, variable compliant actuation seems to be an appropriate solution to achieve energy efficiency and might decrease efforts to implement user-centered control schemes that do not disturb the amputee.
In this talk, technical and psychological issues of powered lower limb prostheses are discussed. An user-centered design approach utilizing surveys and expert studies will be proposed as well as a variable compliant actuator based on torsion. Position and stiffness control of this actuator are investigated. In order to exploit natural system dynamics in stiffness control, those are analyzed, adjustment laws are derived and applied in combination with frequency analysis.
Philipp Beckerle received his Dipl.-Ing. (equivalent to M.Sc.) from Technische Universität Darmstadt, Germany in 2009. Currently, he works as a full-time research associate at Institute for Mechatronic Systems in Mechanical Engineering at Technische Universität Darmstadt, Germany. His main research topics are user-centered design of mechatronic prostheses and other assistive robotic systems. His further interest is in modeling, simulation and control of dynamic systems, model-based fault diagnosis as well as human-machine interaction and cybernetics.