Proposal of air compressing device using walking vibration energy regeneration for pneumatic driven assistive device

Pneumatically driven wearable assistive devices for walking have been developed recently. These devices can achieve flexible assistance without control; however, they require large and heavy air compressors for activation. In this study, a pneumatically driven source using vibration energy regeneration from walking was developed. The aim was to activate the cylinder using vibrations due to walking and compressed air. A mass element, which is connected to a human body via a spring and a cylinder, vibrates along with the human gait cycle. Next, a prototype was developed and tested. In walking experiments, stored pressure was measured at several gait cycles and masses for comparison. Results indicate that the gait cycle period and masses affect the stored pressure; the highest pressure recorded was 0.08 MPa

Computational Synthesis of Wearable Robot Mechanisms: Application to Hip-Joint Mechanisms

Since wearable linkage mechanisms could control the moment transmission from actuator(s) to wearers, they can help ensure that even low-cost wearable systems provide advanced functionality tailored to users' needs. For example, if a hip mechanism transforms an input torque into a spatially-varying moment, a wearer can get effective assistance both in the sagittal and frontal planes during walking, even with an affordable single-actuator system. However, due to the combinatorial nature of the linkage mechanism design space, the topologies of such nonlinear-moment-generating mechanisms are challenging to determine, even with significant computational resources and numerical data. Furthermore, on-premise production development and interactive design are nearly impossible in conventional synthesis approaches. Here, we propose an innovative autonomous computational approach for synthesizing such wearable robot mechanisms, eliminating the need for exhaustive searches or numerous data sets. Our method transforms the synthesis problem into a gradient-based optimization problem with sophisticated objective and constraint functions while ensuring the desired degree of freedom, range of motion, and force transmission characteristics. To generate arbitrary mechanism topologies and dimensions, we employed a unified ground model. By applying the proposed method for the design of hip joint mechanisms, the topologies and dimensions of non-series-type hip joint mechanisms were obtained. Biomechanical simulations validated its multi-moment assistance capability, and its wearability was verified via prototype fabrication. The proposed design strategy can open a new way to design various wearable robot mechanisms, such as shoulders, knees, and ankles.Comment: 28 pages, 7 figures, Supplementary Material

Innovation in augmenting hip and ankle performance during walking

This thesis considers two topics: hip assistance using a powered exoskeleton, and ankle assistance using a passive ankle-foot orthosis during walking. Part A introduces a lightweight bilateral hip exoskeleton used for improving gait function. Part B introduces an adjustable ankle foot orthosis to assist with ankle correction.Exoskeletons are wearable robotic devices that can assist with a variety of tasks, such as load carrying, walking, or rehabilitation. In Part A, I introduce an ultra-lightweight hip exoskeleton aimed at assisting individuals with Cerebral Palsy and other gait impairments during rehabilitation or gait training exercises. This thesis presents the mechanical design and validation of the exoskeleton. The final mechanical design of the hip exoskeleton was derived through several prototypes, and verified for specific engineering requirements: weight, torque application, range of motion, and user comfort. A summary of the hip exoskeleton control system is briefly discussed. Ankle-foot orthoses (AFOs) are devices commonly utilized for gait correction. AFOs are boot-like structures that encase the foot and lower leg to provide extra support and stability to the user during everyday tasks. Current market AFOs are extremely rigid, making walking difficult for individuals due to reduced ankle movement. Part B of this thesis introduces an adjustable AFO to help individuals increase their ankle motion while also aiding ankle power during stance and swing phases of the gait cycle. The final design of the AFO was derived through a single prototype, and validated for specific engineering requirements: weight, spring stiffness, modification ability, range of motion, and comfort