Integration, Sensing, and Control of a Modular Soft-Rigid Pneumatic Lower Limb Exoskeleton

Wang, Jiangbei; Fei, Yanqiong; Chen, Weidong

doi:10.1089/soro.2019.0023

Cited by 36 publications

(18 citation statements)

References 30 publications

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“…This material can be a rigid or semi-rigid tube, in this case, the bending sensor will be referred as a “Tubular Active Bending Sensor”, or it can be made of a rubber film, such as a “Rubber Active Bending Sensor”. In artificial pneumatic muscles [ 108 ], the elasticity of a rubber film can be produced using air pressure. For non-rigid materials, there are several techniques used to deform them: torsion, compression, shear and stretching [ 62 ].…”

Section: Analytical Reviewmentioning

confidence: 99%

Sensors and Actuation Technologies in Exoskeletons: A Review

Tiboni

Borboni

Vérité

et al. 2022

Sensors

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Exoskeletons are robots that closely interact with humans and that are increasingly used for different purposes, such as rehabilitation, assistance in the activities of daily living (ADLs), performance augmentation or as haptic devices. In the last few decades, the research activity on these robots has grown exponentially, and sensors and actuation technologies are two fundamental research themes for their development. In this review, an in-depth study of the works related to exoskeletons and specifically to these two main aspects is carried out. A preliminary phase investigates the temporal distribution of scientific publications to capture the interest in studying and developing novel ideas, methods or solutions for exoskeleton design, actuation and sensors. The distribution of the works is also analyzed with respect to the device purpose, body part to which the device is dedicated, operation mode and design methods. Subsequently, actuation and sensing solutions for the exoskeletons described by the studies in literature are analyzed in detail, highlighting the main trends in their development and spread. The results are presented with a schematic approach, and cross analyses among taxonomies are also proposed to emphasize emerging peculiarities.

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Section: Analytical Reviewmentioning

confidence: 99%

Sensors and Actuation Technologies in Exoskeletons: A Review

Tiboni

Borboni

Vérité

et al. 2022

Sensors

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show abstract

“…Recently, various lower limb exoskeletons (LLEs) have been proposed for aiding people with lower limb motor dysfunction, soldiers, and workers [1][2][3][4]. The LLEs are mainly divided into three categories according to the used materials: rigid LLEs made up of hard linkages, soft-driven LLEs which have soft actuators and rigid frame and joints, and soft LLEs without rigid frames and joints but consist of garments, cables or straps [5]. A high and precise force can be obtained by using a rigid LLE, but its large stiffness limits the natural motion of a wearer [6,7] and the misalignment of the biological joint may cause secondary injury to a patient [8].…”

Section: Introductionmentioning

confidence: 99%

Biomechanical and Physiological Evaluation of a Multi-Joint Exoskeleton with Active-Passive Assistance for Walking

et al. 2021

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How to improve the walking efficiency while ensuring the wearability is an important issue of lower limb exoskeletons. Active devices can provide greater forces, while the passive devices have advantage in weight. We presented a multi-joint exoskeleton with active hip extension assistance and passive ankle plantarflexion assistance in this work. An admittance controller based on a feedforward model was proposed to track the desired active force of the hip extension. An underfoot clutch mechanism was adapted to realize the passive ankle plantarflexion assistance. To assess the efficacy of the multi-joint exoskeleton in assisting walking, we conducted comprehensive experiments to evaluate the force tracking performance, lower limb muscle activities and metabolic cost. The results demonstrated that: (i) The average tracking error of the peak hip extension assistance force from three subjects was less than 3%. (ii) The reductions of normalized root-mean-square EMG in the lateral soleus, medial soleus and gluteus maximus of eight subjects achieved 15.33%, 11.11%, and 3.74%, respectively. (iii) The average metabolic cost of six subjects was reduced by 10.41% under exoskeleton on (EO) condition comparing to the condition of walking with no exoskeleton (NE). This work proved that the concept of the multi-joint exoskeleton with active-passive assistance can improve the walking efficiency.

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“…In addition, changing the power source or removing the power of the exoskeleton may also be a method to reduce the weight of the system. Wang et al [ 18 ] designed a modular soft-rigid pneumatic lower limb exoskeleton that assists the hip, knee, and ankle joints pneumatically, which proves that one actuator is capable of driving all six joints of the lower limbs. Pneumatic muscles mimic the strength of human muscles by contracting length, but often in the same amount as the number of joints that need to be assisted [ 19 , 20 , 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

A Time Division Multiplexing Inspired Lightweight Soft Exoskeleton for Hip and Ankle Joint Assistance

Chen

Shi

et al. 2021

Micromachines

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Exoskeleton robots are frequently applied to augment or assist the user’s natural motion. Generally, each assisted joint corresponds to at least one specific motor to ensure the independence of movement between joints. This means that as there are more joints to be assisted, more motors are required, resulting in increasing robot weight, decreasing motor utilization, and weakening exoskeleton robot assistance efficiency. To solve this problem, the design and control of a lightweight soft exoskeleton that assists hip-plantar flexion of both legs in different phases during a gait cycle with only one motor is presented in this paper. Inspired by time-division multiplexing and the symmetry of walking motion, an actuation scheme that uses different time-periods of the same motor to transfer different forces to different joints is formulated. An automatic winding device is designed to dynamically change the loading path of the assistive force at different phases of the gait cycle. The system is designed to assist hip flexion and plantar flexion of both legs with only one motor, since there is no overlap between the hip flexion movement and the toe-offs movement of the separate legs during walking. The weight of the whole system is only 2.24 kg. PD iterative control is accomplished by an algorithm that utilizes IMUs attached on the thigh recognizing the maximum hip extension angle to characterize toe-offs indirectly, and two load cells to monitor the cable tension. In the study of six subjects, muscle fatigue of the rectus femoris, vastus lateralis, gastrocnemius and soleus decreased by an average of 14.69%, 6.66%, 17.71%, and 8.15%, respectively, compared to scenarios without an exoskeleton.

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Integration, Sensing, and Control of a Modular Soft-Rigid Pneumatic Lower Limb Exoskeleton

Cited by 36 publications

References 30 publications

Sensors and Actuation Technologies in Exoskeletons: A Review

Sensors and Actuation Technologies in Exoskeletons: A Review

Biomechanical and Physiological Evaluation of a Multi-Joint Exoskeleton with Active-Passive Assistance for Walking

A Time Division Multiplexing Inspired Lightweight Soft Exoskeleton for Hip and Ankle Joint Assistance

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