Lower limb exoskeleton robot and its cooperative control: A review, trends, and challenges for future research

Frontiers in Neurorobotics, Journal Year: 2023, Volume and Issue: 16

Published: Jan. 11, 2023

Effective control of an exoskeleton robot (ER) using a human-robot interface is crucial for assessing the robot's movements and force they produce to generate efficient signals. Interestingly, certain surveys were done show off cutting-edge robots. The review papers that previously published have not thoroughly examined strategy, which component automating systems. As result, this focuses on examining most recent developments problems associated with systems, particularly during last few years (2017-2022). In addition, trends challenges cooperative control, multi-information fusion, are discussed.

Language: Английский

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Gait Prediction and Variable Admittance Control for Lower Limb Exoskeleton With Measurement Delay and Extended-State-Observer

IEEE Transactions on Neural Networks and Learning Systems, Journal Year: 2022, Volume and Issue: 34(11), P. 8693 - 8706

Published: March 19, 2022

The measurement delay of the feedback control system is a universal problem in industrial engineering, which will degrade output performance, especially causing undesirable chatter responses. In this study, deep-Gaussian-process (DGP)-based method for operator's gait prediction proposed to estimate real-time motion intention and compensate inertial unit (IMU). On basis these uncertainties quantified by DGP method, variable admittance controller designed reduce human-exoskeleton interaction torque. reference trajectory generated controller, smoothed two-order Bessel interpolation. Meanwhile, parameters are self-regulated based on defined uncertainty index prediction. extend-state observer (ESO) with backstepping iteration adopted unmeasured state, model uncertainties, unmodeled dynamics lower limb exoskeleton. effectiveness scheme verified both comparative simulations experimental results cooperative motion.

Language: Английский

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Haptic Transparency and Interaction Force Control for a Lower Limb Exoskeleton

IEEE Transactions on Robotics, Journal Year: 2024, Volume and Issue: 40, P. 1842 - 1859

Published: Jan. 1, 2024

Controlling the interaction forces between a human and an exoskeleton is crucial for providing transparency or adjusting assistance resistance levels. However, it open problem to control of lower-limb exoskeletons designed unrestricted overground walking. For these types exoskeletons, challenging implement force/torque sensors at every contact user direct force measurement. Moreover, important compensate exoskeleton's whole-body gravitational dynamical forces, especially heavy exoskeletons. Previous works either simplified dynamic model by treating legs as independent double pendulums, they did not close loop with feedback. The proposed whole-exoskeleton closed-loop compensation (WECC) method calculates torques during complete gait cycle using dynamics joint torque measurements on hip-knee exoskeleton. Furthermore, uses constrained optimization scheme track desired in closed while considering physical safety constraints. We evaluated haptic tracking WECC three subjects. also compared performance controller based passive version results consistently low absolute error whole both zero nonzero torques. In contrast, yields poor stance phase

Language: Английский

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$\rm PI^{{\text{2}}}$-Based Adaptive Impedance Control for Gait Adaption of Lower Limb Exoskeleton

IEEE/ASME Transactions on Mechatronics, Journal Year: 2024, Volume and Issue: 29(6), P. 4251 - 4261

Published: March 18, 2024

Lower limb exoskeletons are becoming increasingly popular for aiding individuals with disabilities or limited locomotion abilities. Existing lower mainly focus on walking gait to perform medical rehabilitation training; however, the behavior patterns of patients diverse, and a single cannot satisfy demands daily life. In order promote assisting performance subject various types gaits, this article proposes policy improvement path integrals ( $\rm {PI^{2}}$ )-based adaptive impedance control strategy. Our proposed method employs hierarchical structure. First, zero moment point concept is employed generate desired angle trajectories hip joint knee under three gaits: walking, squatting, climbing. On basis, optimization incorporated track generated trajectory, wherein parameters optimized using deviation between actual trajectory exoskeleton. The human–robot interaction forces guaranteed remain within small threshold even gaits. Comparative simulations exoskeleton wearing experiments conducted validate effectiveness superiority method.

Language: Английский

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Review on Control Strategies for Lower Limb Rehabilitation Exoskeletons

IEEE Access, Journal Year: 2021, Volume and Issue: 9, P. 123040 - 123060

Published: Jan. 1, 2021

Research on lower limb exoskeleton (LLE) for rehabilitation have developed rapidly to meet the need of population with neurologic injuries. LLEs include therapeutic that aim restore walking ability patients, and assistive offer support activities in daily life. A substantial part them can serve both purposes. However, these devices are yet reach final goal performing human-machine joint movement agilely smartly. Control strategy plays an important role achieving their designed goal. At present, control strategies face three major challenges: how detect human intention, do motion given intentions, optimize parameters suit different individuals. As a contribution, this paper offers overview state-of-the-art by classifying into eight categories, each which is presented technical summary tabulated information representative papers. Moreover, current approaches addressing challenges discussed macroscopic perspective. Finally, it has been explored requirements future should maximizing performance LLEs.

Language: Английский

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Hierarchical Classification of Subject-Cooperative Control Strategies for Lower Limb Exoskeletons in Gait Rehabilitation: A Systematic Review

Machines, Journal Year: 2023, Volume and Issue: 11(7), P. 764 - 764

Published: July 22, 2023

Over the last decade, lower limb exoskeletons have seen significant development, with a particular focus on improving interaction between subject and exoskeleton. This has been achieved by implementing advanced control strategies that enable safe efficient use of In this work, for are divided into upper-level (supervisory high-level control) lower-level (the servo layer). Before discussing these strategies, brief introduction to their schemes is provided. The hierarchy then systematically reviewed along an overview techniques used. A Preferred Reporting Items Systematic Reviews Meta-Analysis (PRISMA) statement used highlight systematic process identifying relevant articles inclusion exclusion criteria. details supervisory control, presented citing state-of-the-art studies, particularly from past five years. targeted joint, training mode, development stage different highlighted in tabulated form articulate overall level. Finally, potential opportunities limitations subject-cooperative discussed. Overall, work aims provide in-depth understanding exoskeletons, focusing cooperation. knowledge can be improve safety efficacy ultimately benefiting individuals mobility impairments.

Language: Английский

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Flexible assistance strategy of lower limb rehabilitation exoskeleton based on admittance model

Science China Technological Sciences, Journal Year: 2024, Volume and Issue: 67(3), P. 823 - 834

Published: Jan. 20, 2024

Language: Английский

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Adaptive Gait Training for a Lower Limb Rehabilitation Robot Using Human-Robot Interaction Force

Cyborg and Bionic Systems, Journal Year: 2024, Volume and Issue: 5

Published: Jan. 1, 2024

The existing fixed gait lower limb rehabilitation robots perform a predetermined walking trajectory for patients, ignoring their residual muscle strength. To enhance patient participation and safety in training, this paper aims to develop robot with adaptive training capability relying on human-robot interaction force measurement. Firstly, novel system several active passive driven joints is developed, 2 face-to-face mounted cantilever beam sensors are employed measure the forces. Secondly, dynamic model of constructed estimate forces human leg completely state. Thereafter, based theoretical moment from dynamics actual joint collected by sensors, an adjustment method proposed achieve goal adapting wearer's movement intention. Finally, interactive experiments carried out validate effectiveness developed system. gaits offers great potential future high-quality e.g., improving safety.

Language: Английский

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Periodic event-triggered sliding mode control for lower limb exoskeleton based on human–robot cooperation

ISA Transactions, Journal Year: 2021, Volume and Issue: 123, P. 87 - 97

Published: May 31, 2021

Language: Английский

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ViT-based Terrain Recognition System for wearable soft exosuit

Biomimetic Intelligence and Robotics, Journal Year: 2023, Volume and Issue: 3(1), P. 100087 - 100087

Published: Jan. 17, 2023

Terrain classification and force assistance strategies in complex environments have always piqued the interest of many researchers. For wearable soft exosuits, inaccurate terrain recognition can easily introduce undesired assist forces that injure wearer. Because these problems, we introduced a depth camera into exosuit system, perform based on Vision Transformer (ViT), optimized control algorithm, which is known as ViT-Based Recognition System (TTRS). First, used algorithm to achieve considerable effect recognition. We also prior knowledge strategy exosuit, providing different terrains. Subsequently, performed human experiments with seven able-bodied people (six males one female). The promising results demonstrate our accuracy reach 99.2% under six terrains it smoothly switch force–assist curve better adapt improve walking effect. aforementioned algorithms may positively influence study powered prostheses, orthotics.

Language: Английский

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