For powered prosthetic legs to be viable in everyday situations, they require an activity classification system that is not only accurate but also straightforward understand and use. However, incorporating the numerous modes real-world ambulation often requires high-dimensional feature spaces restrictions on leg leading each transition. This paper addresses these challenges by delegating sit/stand transitions variable-incline walking mid-level controller, effectively reducing space four...

Lower-limb exoskeletons have undergone significant developments for aiding in the ambulation of adults with gait impairment. However, advancements pediatric population comparatively been lacking. This paper presents a newly developed joint actuator designed to drive hip and knee joints lower-limb exoskeleton. The performance requirements associated actuators were determined based on target audience children ages 6–11 years old. incorporate hybrid belt-chain transmission driven by frameless...

Robotic knee-ankle prostheses have often fallen short relative to passive microprocessor in time-based clinical outcome tests. User ambulation endurance is an alternative metric that may better highlight the benefits of robotic prostheses. However, previous studies were unable show due inaccurate high-level classification, discretized mid-level control, and insufficiently difficult tasks. In this case study, we present a phase-based prosthesis controller which yields biomimetic joint...

Abstract Hybrid zero dynamics (HZD) control creates dynamically stable gaits by driving a hybrid robot model toward an optimally generated state-dependent reference signal. This paper presents the first application of HZD to underactuated lower-limb exoskeleton for gait guidance. A phase-based is follow nominal walking pattern. Simulation results using proportional-derivative (PD) controller validate that periodic similar possible identified human-exoskeleton model. For hardware application,...

This paper describes the first stages of hardware development and preliminary assessment for a powered lower limb orthosis designed to provide gait assistance rehabilitation children with walking impairments, such as those associated cerebral palsy spina bifida. The design requirements, including range motion, speeds, torques, powers, are investigated presented based on target user age 6–11 years old. A three stage joint actuator is designed, built, tested against requirements. 0.6 kg...

Pediatric gait rehabilitation and guidance strategies using robotic exoskeletons require a controller that encourages user volitional control participation while guiding the wearer towards stable cycle. Virtual constraint-based controllers have created cycles in bipedal systems seen recent use assistive exoskeletons. This paper evaluates virtual for pediatric through comparison with traditional time-dependent position tracking on newly developed exoskeleton system. Walking experiments were...

This paper presents an innovative design methodology for development of lower limb exoskeletons with the fabrication and experimental evaluation prototype hardware. The proposed approach is specifically conceived to be suitable pediatric population uses additive manufacturing a model parameterized in terms subject anthropometrics give person-specific custom fit. applied create computer-aided models using average children 6-11 years old individual measured by researchers. demonstrates that...

Exoskeleton technology has undergone significant developments for the adult population but is still lacking pediatric population. This paper presents design of a hip–knee exoskeleton children 6 to 11 years old with gait abnormalities. The actuators are housed in an adjustable frame where thigh part can adjust length and hip cradle medial-lateral posterior-anterior directions concurrently. Proper control exoskeletons follow nominal healthy patterns time-invariant manner important ease use...

Passive prosthetic legs require undesirable compensations from amputee users to avoid stubbing obstacles and stairsteps. Powered prostheses can reduce those by restoring normative joint biomechanics, but the absence of user proprioception volitional control combined with environmental awareness prosthesis increases risk collisions. This article presents a novel stub avoidance controller that automatically adjusts knee/ankle kinematics based on suprasensory measurements distance small,...

One of the primary benefits emerging powered prosthetic legs is their ability to facilitate step-over-step stair ascent by providing positive mechanical work. Existing control methods typically have distinct steady-state activity modes for walking and ascent, where transitions involve discretely switching between controllers often must be initiated with a particular leg. However, these discrete do not necessarily replicate able-bodied joint biomechanics, which been shown continuously adjust...

The nominal gait of each individual is unique and varies with the walking speed person. This poses a difficult problem for powered rehabilitative orthoses since control strategies often require reference trajectory give little to patient. paper describes simple approach which applies torque resistive joint movement that unnatural healthy individuals in hip knee joints during swing phase gait. controller uses configuration-dependent orthonormal basis represent vectors terms components are...

Abstract This paper presents a novel impedance controller modified with switching strategy for the purpose of improving safety in human–robot interactions. Under normal operating conditions, an is enabled when adequate tracking performance maintained presence bounded disturbances. However, if disturbances are greater than anticipated such that degraded, proposed temporarily switches modes to control better apt limit inputs. With returning prescribed bounds, will be restored and resume...

Although powered prosthetic legs have demonstrated energetic benefits by replicating normative joint biomechanics during steady-state activities like walking and stair climbing, transitions between these are usually handled discretely switching controllers without considering biomimicry or the distinct role of leading leg. This study introduces two approaches for facilitating seamless inter-leg (i.e., initiated either intact leg) ascent/descent using a data-driven, phasebased kinematic...

Research in powered prosthesis control has explored the use of impedance-based algorithms due to their biomimetic capabilities and intuitive structure. Modern impedance controllers feature parameters that smoothly vary over gait phase task according a data-driven model. However, these recent efforts only continuous during stance instead utilize discrete transition logic switch kinematic swing, necessitating two separate models for different parts stride. In contrast, this paper presents...

Although powered prosthetic legs have enabled more biomimetic joint kinematics during steady-state activities like walking and stair climbing, transitions between these are usually handled by discretely switching controllers without considering biomimicry or the distinct role of leading leg. This study introduces two data-driven, phase-based kinematic control approaches for seamless inter-leg (i.e., initiated either intact leg) ascent/descent, assuming high-level knowledge upcoming activity....

Abstract Linear robust control techniques such as μ-synthesis can be used to design controllers for linear systems guarantee specified performance criteria in the presence of modeling uncertainties, disturbances, and sensor noise. However, these are rather uncommon robotics due nonlinear nature plant where direct application would require large model uncertainties therefore may only create a satisfactory controller if using lenient criteria. The inclusion feedback linearization rectify this...

<p>Many powered prosthetic devices use load cells to detect ground interaction forces and gait events. These sensors introduce additional weight cost in the device. Recent proprioceptive actuators enable an algebraic relationship be?tween actuator torques contact forces. This paper presents a force sensing paradigm which esti?mates reaction as solution events without cell. A floating body dynamic model is obtained with constraints at center of pressure representing foot-ground...

Many powered prosthetic devices use load cells to detect ground interaction forces and gait events. These sensors introduce additional weight cost in the device. Recent proprioceptive actuators enable an algebraic relationship between actuator torques contact forces. This paper presents a force sensing paradigm which estimates reaction as solution events without cell. A floating body dynamic model is obtained with constraints at center of pressure representing foot-ground interaction....

<p>Passive prosthetic legs require undesirable compensations from amputee users to avoid stubbing obstacles and stairsteps. Powered prostheses can reduce those by restoring normative joint biomechanics, but the absence of user proprioception volitional control combined with environmental awareness prosthesis increases risk collisions. This paper presents a novel stub avoidance controller that automatically adjusts knee/ankle kinematics based on suprasensory measurements distance small,...

<p>Passive prosthetic legs require undesirable compensations from amputee users to avoid stubbing obstacles and stairsteps. Powered prostheses can reduce those by restoring normative joint biomechanics, but the absence of user proprioception volitional control combined with environmental awareness prosthesis increases risk collisions. This paper presents a novel stub avoidance controller that automatically adjusts knee/ankle kinematics based on suprasensory measurements distance small,...