For stroke survivors and many other people with upper-extremity impairment, daily life can be difficult without properly functioning arms. Some modern physical therapy exercises focus on rehabilitating people with these troubles by correcting patients' perceptions of their own body to eventually regain complete control and strength over their arms again. Augmentative wearable robots, such as the upper-extremity exoskeletons and exosuits, may be able to assist in this endeavor. A common drawback in many of these exoskeletons, however, is their inability to conform to the natural flexibility of the human body without a rigid base. We have built one such exosuit to address this challenge: Compliant Robotic Upper-extremity eXosuit (CRUX). This robot is a compliant, lightweight, multi-DoF, portable exosuit that affords its wearer the ability to augment themselves in many unconventional settings (i.e. outside of a clinic). These attributes are largely achieved by using a modified tensegrity design situated according to measured lines of minimal-extension, where a network of tension members provide a foundation to apply augmentative forces via precisely placed power-lines. In this paper, we detail the design process of CRUX, the report on CRUX's prototypical composition, and describe the mimetic control algorithm used. We also discuss the results of three studies that illustrate the efficacy of CRUX's mimetic controller, CRUX's flexibility and compliance, and the metabolic cost reduction when users exercise with assistance from CRUX as opposed to without. We conclude this paper with a summary of our findings, potential use cases for this technology, and the direction of future related work.

Wearable robots can potentially offer their users enhanced stability and strength. These augmentations are ideally designed to actuate harmoniously with the user's movements and provide extra force as needed. The creation of such robots, however, is particularly challenging due to the underlying complexity of the human body. In this paper, we present a compliant, robotic exosuit for upper extremities called CRUX. This exosuit, inspired by tensegrity models of the human arm, features a lightweight (1.3 kg), flexible multi-joint design for portable augmentation. We also illustrate how CRUX maintains the full range of motion of the upper-extremities for its users while providing multi-DoF strength amplification to the major muscles of the arm, as evident by tracking the heart rate of an individual exercising said arm. Exosuits such as CRUX may be useful in physical therapy and in extreme environments where users are expected to exert their bodies to the fullest extent.

Most traditional robotic mechanisms feature inelastic joints that are unable to robustly handle large deformations and off-axis moments. As a result, the applied loads are transferred rigidly throughout the entire structure. The disadvantage of this approach is that the exerted leverage is magnified at each subsequent joint possibly damaging the mechanism. In this paper, we present two lightweight, elastic, bio-inspired tensegrity robotic arms adapted from prior static models which mitigate this danger while improving their mechanism's functionality. Our solutions feature modular tensegrity structures that function similarly to the human elbow and the human shoulder when connected. Like their biological counterparts, the proposed robotic joints are flexible and comply with unanticipated forces. Both proposed structures have multiple passive degrees of freedom and four active degrees of freedom (two from the shoulder and two from the elbow). The structural advantages demonstrated by the joints in these manipulators illustrate a solution to the fundamental issue of elegantly handling off-axis compliance. Additionally, this initial experiment illustrates that moving tensegrity arms must be designed with large reachable and dexterous workspaces in mind, a change from prior tensegrity arms which were only static. These initial experiments should be viewed as an exploration into the design space of active tensegrity structures, particularly those inspired by biological joints and limbs.

Abstract-In this paper, we present a light-weight, multiaxis compliant tenegrity joint that is biologically inspired by the human elbow. This tensegrity elbow actuates by shortening and lengthening cable in a method inspired by muscular actuation in a person. Unlike many series elastic actuators, this joint is structurally compliant not just along each axis of rotation, but along other axes as well. Compliant robotic joints are indispensable in unpredictable environments, including ones where the robot must interface with a person. The joint also addresses the need for functional redundancy and flexibility, traits which are required for many applications that investigate the use of biologically accurate robotic models.

The flexibility and structural compliance of the biological shoulder joint allows humans to perform a wide range of motions with their arms. The current paper is a preliminary study in which we propose a structurally compliant robotic manipulator joint inspired by the human shoulder joint, which elastically deforms when actuated. The tensile actuation is similar to the contraction and extension of biological muscles. We present four separate models for the shoulder: a simple saddle, a complex saddle, a suspended tubercle, and interlocked tetrahedrons. The analysis explores the dynamics in each design to compare the inherent advantages and disadvantages, which gives insight into the design and development of better interfaces for biologically inspired human-oriented robotics.

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Dans un contexte de rareté et de pénurie de main-d’œuvre, les médias sociaux représentent d’importants canaux de communication dans la diffusion de la marque employeur. En plus de rejoindre de nombreux publics et d’interagir avec eux, les médias sociaux permettent d’intéresser et de mettre à l’avant-plan les employés, ce qui permet, au final, d’humaniser l’entreprise. Néanmoins, une organisation doit s’assurer de prévoir des ressources financières suffisantes ainsi que de consacrer le temps et les efforts nécessaires dans la gestion de sa présence en ligne. Tout en encadrant et en formant les employés pour qu’ils deviennent de bons ambassadeurs de la marque, l’entreprise doit également veiller à prévenir les débordements en mettant en place une gestion de crise.