W-FYD: a Wearable Fabric-based Display for Haptic Multi-Cue Delivery and Tactile Augmented Reality

Despite the importance of softness, there is no evidence of wearable haptic systems able to deliver controllable softness cues. Here, we present the Wearable Fabric Yielding Display (W-FYD), a fabric-based display for multi-cue delivery that can be worn on user's finger and enables, for the first time, both active and passive softness exploration. It can also induce a sliding effect under the finger-pad. A given stiffness profile can be obtained by modulating the stretching state of the fabric through two motors. Furthermore, a lifting mechanism allows to put the fabric in contact with the user's finger-pad, to enable passive softness rendering. In this paper, we describe the architecture of W-FYD, and a thorough characterization of its stiffness workspace, frequency response and softness rendering capabilities. We also computed device Just Noticeable Difference in both active and passive exploratory conditions, for linear and non-linear stiffness rendering as well as for sliding direction perception. The effect of device weight was also considered. Furthermore, performance of participants and their subjective quantitative evaluation in detecting sliding direction and softness discrimination tasks are reported. Finally, applications of W-FYD in tactile augmented reality for open palpation are discussed, opening interesting perspectives in many fields of human-machine interaction

Modulating the Perceived Softness of Real Objects Through Wearable Feel-Through Haptics

In vision, Augmented Reality (AR) allows the superposition of digital content on real-world visual information, relying on the well-established See-through paradigm. In the haptic domain, a putative Feel-through wearable device should allow to modify the tactile sensation without masking the actual cutaneous perception of the physical objects. To the best of our knowledge, a similar technology is still far to be effectively implemented. In this work, we present an approach that allows, for the first time, to modulate the perceived softness of real objects using a Feel-through wearable that uses a thin fabric as interaction surface. During the interaction with real objects, the device can modulate the growth of the contact area over the fingerpad without affecting the force experienced by the user, thus modulating the perceived softness. To this aim, the lifting mechanism of our system warps the fabric around the fingerpad in a way proportional to the force exerted on the specimen under exploration. At the same time, the stretching state of the fabric is controlled to keep a loose contact with the fingerpad. We demonstrated that different softness perceptions for the same specimens can be elicited, by suitably controlling the lifting mechanism of the system

From humans to robots: The role of cutaneous impairment in human environmental constraint exploitation to inform the design of robotic hands

Human hands are capable of a variety of movements, thanks to their extraordinary biomechanical structure and relying on the richness of human tactile information. Recently, soft robotic hands have opened exciting possibilities and, al the same time, new issues related to planning and control. In this work, we propose to study human strategies in environmental constraint exploitation to grasp objects from a table. We have considered both the case where participants' fingertips were free and with a rigid shell worn on them to understand the role of cutaneous touch. Main kinematic strategies were quantified and classified in an unsupervised manner. The principal strategies appear to be consistent in both experimental conditions, although cluster cardinality differs. Furthermore, as expected, tactile feedback improves both grasp precision and quality performance. Results opens interesting perspective for sensing and control of soft manipulators

A Multi-Modal Sensing Glove for Human Manual-Interaction Studies

We present an integrated sensing glove that combines two of the most visionary wearable sensing technologies to provide both hand posture sensing and tactile pressure sensing in a unique, lightweight, and stretchable device. Namely, hand posture reconstruction employs Knitted Piezoresistive Fabrics that allows us to measure bending. From only five of these sensors (one for each finger) the full hand pose of a 19 degrees of freedom (DOF) hand model is reconstructed leveraging optimal sensor placement and estimation techniques. To this end, we exploit a-priori information of synergistic coordination patterns in grasping tasks. Tactile sensing employs a piezoresistive fabric allowing us to measure normal forces in more than 50 taxels spread over the palmar surface of the glove. We describe both sensing technologies, report on the software integration of both modalities, and describe a preliminary evaluation experiment analyzing hand postures and force patterns during grasping. Results of the reconstruction are promising and encourage us to push further our approach with potential applications in neuroscience, virtual reality, robotics and tele-operation

A Synergy-Based Optimally Designed Sensing Glove for Functional Grasp Recognition

Achieving accurate and reliable kinematic hand pose reconstructions represents a challenging task. The main reason for this is the complexity of hand biomechanics, where several degrees of freedom are distributed along a continuous deformable structure. Wearable sensing can represent a viable solution to tackle this issue, since it enables a more natural kinematic monitoring. However, the intrinsic accuracy (as well as the number of sensing elements) of wearable hand pose reconstruction (HPR) systems can be severely limited by ergonomics and cost considerations. In this paper, we combined the theoretical foundations of the optimal design of HPR devices based on hand synergy information, i.e., the inter-joint covariation patterns, with textile goniometers based on knitted piezoresistive fabrics (KPF) technology, to develop, for the first time, an optimally-designed under-sensed glove for measuring hand kinematics. We used only five sensors optimally placed on the hand and completed hand pose reconstruction (described according to a kinematic model with 19 degrees of freedom) leveraging upon synergistic information. The reconstructions we obtained from five different subjects were used to implement an unsupervised method for the recognition of eight functional grasps, showing a high degree of accuracy and robustness

Postural Hand Synergies during Environmental Constraint Exploitation

Humans are able to intuitively exploit the shape of an object and environmental constraints to achieve stable grasps and perform dexterous manipulations. In doing that, a vast range of kinematic strategies can be observed. However, in this work we formulate the hypothesis that such ability can be described in terms of a synergistic behavior in the generation of hand postures, i.e., using a reduced set of commonly used kinematic patterns. This is in analogy with previous studies showing the presence of such behavior in different tasks, such as grasping. We investigated this hypothesis in experiments performed by six subjects, who were asked to grasp objects from a flat surface. We quantitatively characterized hand posture behavior from a kinematic perspective, i.e., the hand joint angles, in both pre-shaping and during the interaction with the environment. To determine the role of tactile feedback, we repeated the same experiments but with subjects wearing a rigid shell on the fingertips to reduce cutaneous afferent inputs. Results show the persistence of at least two postural synergies in all the considered experimental conditions and phases. Tactile impairment does not alter significantly the first two synergies, and contact with the environment generates a change only for higher order Principal Components. A good match also arises between the first synergy found in our analysis and the first synergy of grasping as quantified by previous work. The present study is motivated by the interest of learning from the human example, extracting lessons that can be applied in robot design and control. Thus, we conclude with a discussion on implications for robotics of our findings

APLICAÇÃO DE UM PRODUTO À BASE DE AMINOÁCIDO EM TRIGO

A utilização de produtos á base de aminoácidos, como complemento da adubação, vem sendo utilizada na agricultura. O objetivo deste uso é elevar os rendimentos na produção e melhor os padrões de qualidade. Pretende-se que fornecendo á planta uma solução contendo aminoácidos livres, os mesmos serão absorvidos diretamente, sendo incorporada ao metabolismo com considerável economia de energia. A utilização de novos produtos na agricultura sem recomendação da pesquisa oficial vem sendo feita há muito tempo e cada vez mais freqüentemente. Os aminoácidos são uma gama desses novos produtos, com grande expectativas juntos aos produtores por um aumento no rendimento da cultura com maiores lucratividades. O objetivo deste trabalho será avaliar a cultua do trigo em relação ao uso e dose de produtos á base de aminoácidos. Avaliaram-se alguns componentes do rendimento, mudanças morfológicas e a produção de massa seca da cultura do trigo em um Latossolo Vermelho Distrófico típico. A análise de variância da regressão apresentou diferenças significativas apenas para o número de grãos por espigueta. Conclui-se que a utilização e o aumento das doses aplicadas do produto á base de aminoácido – AGROPEX – não elevaram o número de plantas por metro quadrado, o número de espigueta por espiga, altura de planta e produção de massa seca

Synergy-driven performance enhancement of vision-based 3D hand pose reconstruction

In this work we propose, for the first time, to improve the performance of a Hand Pose Reconstruction (HPR) technique from RGBD camera data, which is affected by self-occlusions, leveraging upon postural synergy information, i.e., a priori information on how human most commonly use and shape their hands in everyday life tasks. More specifically, in our approach, we ignore joint angle values estimated with low confidence through a vision-based HPR technique and fuse synergistic information with such incomplete measures. Preliminary experiments are reported showing the effectiveness of the proposed integration

ASPECTO DA POLUIÇÃO ATMOSFÉRICANO BRASIL

O uso crescente de combustíveis fósseis e o crescimento da demanda de transporte rodoviário vêm aumentando muito a emissão de poluentes no Brasil e noi mundo. Nesse aspecto o Brasil tem alcançado importantes avanços na questão ambiental, porém ainda insuficientes para conter o ritmo de crescimento dos agentes agressivos. Somente a indústria consome 37% da energia mundial e emite 50% do dióxido de carbono, 90% dos óxidos de enxofre todos os produtos químicos que atualmente ameaçam a destruição da camada de ozônio. Tecnologias tem avançado muito no sentido de gerar máquinas e combustíveis menos poluentes ou que não gerem poluição

APLICAÇÃO DE DEJETOS LÍQUIDOS DE SUÍNOS E A BUSCA DA SUSTENT ABILIDADE

Os dejetos suínos, até a década de 70, não constituíam fator preocupante, pois a concentração de animais era pequena e o solo das propriedades tinha capacidade para absorvê-los, ou eram utilizados como adubo orgânico. Porém, o desenvolvimento da suinocultura trouxe a produção de grandes quantidades de dejetos, que não emprega tratamento adequado, se transformou na maior fonte poluidora do solo e mananciais de água. O impacto ambiental das práticas tradicionais de tratamento e de adição de dejetos de suínos, em solos agrícolas, tem motivado a busca de tecnologias compatíveis com o desenvolvimento sustentável e a qualidade de vida. Atualmente, a aplicação de dejetos de suínos em solos agrícolas tem sido muito utilizada, pois este resíduo é fonte de nutrientes. A aplicação dos dejetos de suínos em solos agrícolas, cultivados com o sistema de plantio direto, contudo, pode ser viabilizada com a aplicação desses resíduos no sulco do solo. Embora esse aspecto tenha sido estudado quanto à eficiência agronômica, a busca pela sustentabilidade das pequenas propriedades rurais, ele ainda não foi considerado em termos do impacto ambiental, como por exemplo, o efeito dessa prática sobre o acúmulo de metais, tanto no solo, como nas plantas adubadas com esses dejetos s evita impactos ambientais indesejáveis