DESIGN AND FABRICATION OF AN ADVANCED EXOSKELETON FOR GAIT RESTORATION

This thesis details the design and fabrication of an advanced, hydraulically actuated exoskeleton, with the intention of decreasing weight and increasing performance over a previous proof of concept device. The initial device was invented to provide a method of gait restoration to individuals with paraplegia. It combines two different ideas – functional electrical stimulation of the user’s muscles, and an external, hydraulically actuated exoskeleton. By incorporating the user’s own muscles, this method is theoretically more energy efficient than other alternatives while providing additional health benefits. However, in order to fully realize these advantages, the device must be made smaller and lighter, in order to decrease the overhead energy requirements placed on the user’s own muscular system. To accomplish this, a new exoskeleton was designed, that utilizes all off the advanced manufacturing and fabrication resources of the department. Part count has decreased at the cost of manufacturing complexity, and the use of aluminum and carbon fiber composite material is now prevalent in the device. Neither the hydraulic system nor the controller was modified in any way during this process. The end result of this work is a substantial decrease in overall unit weight (30%), and an estimated decrease in user energy requirements of approximately 15.2%. This was accomplished while maintaining all previous benchmarks in range of motion. It is expected that this will have a positive influence on the operation of the device, particularly in planned future endeavors in stair climbing.