Design and control of powered lower limb prostheses
type: CreativeWork
description: In the development of powered lower-limb prostheses, providing sufficient power and torque to support amputees’ locomotion is a major challenge, considering prostheses’ weight and size limits. Furthermore, regulating the power delivery during locomotion is equally important that gives amputees safe and natural movements. This dissertation aims to address these challenges by investigating new approaches in the actuation and control of powered lower-limb prostheses, with the overarching objective to obtain compact, powerful lower-limb prostheses that interact with amputees and the environment in a coordinated manner. The initial efforts were focused on the design and control of transfemoral (TF, also known as above-knee) prostheses powered by pneumatic muscles, an extraordinary actuator with superb power-to-weight ratio. The first prototype incorporates powered knee and ankle joints in a volumetric profile similar to that of human leg. The unique feature is a single-acting-spring-return mechanism, in which a single pneumatic muscle drives the motion in the torque-demanding direction, while a set of mechanical springs drives the motion in the opposite direction. A finite-state impedance controller has been developed for this prosthesis, which was demonstrated to provide a natural gait. Based on previous success, a novel type of pneumatic muscle, namely double-acting sleeve muscle (DASM), was examined to replace traditional pneumatic muscle. Incorporating a second chamber, the DASM is able to provide additional extensional force without using return springs. Therefore, the prosthesis can be significantly simplified into a more compact and lightweight device. Compared with pneumatic muscles, traditional cylinder-type actuators are more technologically mature. Therefore, the subsequent efforts were to develop a pneumatic cylinder-actuated TF prosthesis, which has great potential for real-world applications. All peripheral components were integrated, including a carbon fib…
abstract: In the development of powered lower-limb prostheses, providing sufficient power and torque to support amputees’ locomotion is a major challenge, considering prostheses’ weight and size limits. Furthermore, regulating the power delivery during locomotion is equally important that gives amputees safe and natural movements. This dissertation aims to address these challenges by investigating new approaches in the actuation and control of powered lower-limb prostheses, with the overarching objective to obtain compact, powerful lower-limb prostheses that interact with amputees and the environment in a coordinated manner. The initial efforts were focused on the design and control of transfemoral (TF, also known as above-knee) prostheses powered by pneumatic muscles, an extraordinary actuator with superb power-to-weight ratio. The first prototype incorporates powered knee and ankle joints in a volumetric profile similar to that of human leg. The unique feature is a single-acting-spring-return mechanism, in which a single pneumatic muscle drives the motion in the torque-demanding direction, while a set of mechanical springs drives the motion in the opposite direction. A finite-state impedance controller has been developed for this prosthesis, which was demonstrated to provide a natural gait. Based on previous success, a novel type of pneumatic muscle, namely double-acting sleeve muscle (DASM), was examined to replace traditional pneumatic muscle. Incorporating a second chamber, the DASM is able to provide additional extensional force without using return springs. Therefore, the prosthesis can be significantly simplified into a more compact and lightweight device. Compared with pneumatic muscles, traditional cylinder-type actuators are more technologically mature. Therefore, the subsequent efforts were to develop a pneumatic cylinder-actuated TF prosthesis, which has great potential for real-world applications. All peripheral components were integrated, including a carbon fib…
author: Wu, Molei
language: en_US
language: English
keywords: Mechanical engineering, Robotics
date published: 2016
date modified: 2026-07-27T18:44:07Z
provider: University of Alabama
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Alabama Libraries