Mechanical Redesign and Fabrication of a 12 DOF Orthotic Lower Limb Exoskeleton and 6 Axis Force-Torque Sensor

This thesis details several modifications to the mechanical design of the Orthotic Lower Limb Exoskeleton (OLL-E) that improve upon the functionality and manufacturability of parts and their assemblies. The changes made to these parts maintain or improve the factor of safety against yield and fatigue failure as compared to the original designs. Design changes are verified by FEA simulations and hand calculations. The changes included in this thesis also allowed parts that were previously difficult or impossible to manufacture using traditional methods to be made in house or outsourced to another machine shop. In addition to the mechanical design changes, this thesis also details the design and implementation of a six axis force-torque sensor built into the foot of OLL-E. The purpose of this sensor is to provide feedback to the central control system and allow OLL-E to be self-balancing. This foot sensor design is calibrated and initial results are discussed and shown to be favorable.