Identifying Haptic Exploratory Procedures by Analyzing Hand Dynamics and Contact Force

Haptic exploratory procedures (EPs) are prototypical hand movements that are linked to the acquisition of specific object properties. In studies of haptic perception, hand movements are often classified into these EPs. Here, we aim to investigate several EPs in a quantitative manner to understand how hand dynamics and contact forces differ between them. These dissimilarities are then used to construct an EP identification model capable of discriminating between EPs based on the index finger position and contact force. The extent to which the instructed EPs were distinct, repeatable, and similar across subjects was confirmed by showing that more than 95 percent of the analyzed trials were classified correctly. Finally, the method is employed to investigate haptic exploratory behavior during similarity judgments based on several object properties. It seems that discrimination based on material properties (hardness, roughness, and temperature) yields more consistent classification results compared to discrimination based on the acquisition of shape information. © 2013 IEEE

Haptography: Capturing and Recreating the Rich Feel of Real Surfaces

Haptic interfaces, which allow a user to touch virtual and remote environments through a hand-held tool, have opened up exciting new possibilities for applications such as computer-aided design and robot-assisted surgery. Unfortunately, the haptic renderings produced by these systems seldom feel like authentic re-creations of the richly varied surfaces one encounters in the real world. We have thus envisioned the new approach of haptography, or haptic photography, in which an individual quickly records a physical interaction with a real surface and then recreates that experience for a user at a different time and/or place. This paper presents an overview of the goals and methods of haptography, emphasizing the importance of accurately capturing and recreating the high frequency accelerations that occur during tool-mediated interactions. In the capturing domain, we introduce a new texture modeling and synthesis method based on linear prediction applied to acceleration signals recorded from real tool interactions. For recreating, we show a new haptography handle prototype that enables the user of a Phantom Omni to feel fine surface features and textures

Active haptic perception in robots: a review

In the past few years a new scenario for robot-based applications has emerged. Service and mobile robots have opened new market niches. Also, new frameworks for shop-floor robot applications have been developed. In all these contexts, robots are requested to perform tasks within open-ended conditions, possibly dynamically varying. These new requirements ask also for a change of paradigm in the design of robots: on-line and safe feedback motion control becomes the core of modern robot systems. Future robots will learn autonomously, interact safely and possess qualities like self-maintenance. Attaining these features would have been relatively easy if a complete model of the environment was available, and if the robot actuators could execute motion commands perfectly relative to this model. Unfortunately, a complete world model is not available and robots have to plan and execute the tasks in the presence of environmental uncertainties which makes sensing an important component of new generation robots. For this reason, today\u2019s new generation robots are equipped with more and more sensing components, and consequently they are ready to actively deal with the high complexity of the real world. Complex sensorimotor tasks such as exploration require coordination between the motor system and the sensory feedback. For robot control purposes, sensory feedback should be adequately organized in terms of relevant features and the associated data representation. In this paper, we propose an overall functional picture linking sensing to action in closed-loop sensorimotor control of robots for touch (hands, fingers). Basic qualities of haptic perception in humans inspire the models and categories comprising the proposed classification. The objective is to provide a reasoned, principled perspective on the connections between different taxonomies used in the Robotics and human haptic literature. The specific case of active exploration is chosen to ground interesting use cases. Two reasons motivate this choice. First, in the literature on haptics, exploration has been treated only to a limited extent compared to grasping and manipulation. Second, exploration involves specific robot behaviors that exploit distributed and heterogeneous sensory data

FEELING FOR FAILURE: HAPTIC FORCE PERCEPTION OF SOFT TISSUE CONSTRAINTS IN A SIMULATED MINIMALLY INVASIVE SURGERY TASK

In minimally invasive surgery (MIS), the ability to accurately interpret haptic information and apply appropriate force magnitudes onto soft tissue is critical for minimizing bodily trauma. Force perception in MIS is a dynamic process in which the surgeon\u27s administration of force onto tissue results in useful perceptual information which guides further haptic interaction and it is hypothesized that the compliant nature of soft tissue during force application provides biomechanical information denoting tissue failure. Specifically, the perceptual relationship between applied force and material deformation rate specifies the distance remaining until structural capacity will fail, or indicates Distance-to-Break (DTB). Two experiments explored the higher-order relationship of DTB in MIS using novice and surgeon observers. Findings revealed that observers could reliably perceive DTB in simulated biological tissues, and that surgeons performed better than novices. Further, through calibration feedback training, sensitivity to DTB can be improved. Implications for optimizing training in MIS are discussed

Visuo-Haptic Exploration for Multimodal Memory

When faced with a novel object, we explore it to understand its shape. This way we combine information coming from different senses, as touch, proprioception and vision, together with the motor information embedded in our motor execution plan. The exploration process provides a structure and constrains this rich flow of inputs, supporting the formation of a unified percept and the memorization of the object features. However, how the exploration strategies are planned is still an open question. In particular, is the exploration strategy used to memorize an object different from the exploration strategy adopted in a recall task? To address this question we used iCube, a sensorized cube which measures its orientation in space and the location of the contacts on its faces. Participants were required to explore the cube faces where little pins were positioned in varying number. Participants had to explore the cube twice and individuate potential differences between the two presentations, which could be performed either haptically alone, or with also vision available. The haptic and visuo-haptic (VH) exploratory strategies changed significantly when finalized to memorize the structure of the object with respect to when the same object was explored to recall and compare it with its memorized instance. These findings indicate that exploratory strategies are adapted not only to the property of the object to be analyzed but also to the prospective use of the resulting representation, be it memorization or recall. The results are discussed in light of the possibility of a systematic modeling of natural VH exploration strategies

Investigating the Impact of Visuohaptic Simulations for the Conceptual Understanding of Electric Field for Distributed Charges

The present study assessed the benefits of a multisensory intervention on the conceptual understanding of electric field for distributed charges in engineering and technology undergraduate students. A novel visuohaptic intervention was proposed, which focused on exploring the forces around the different electric field configurations for distributed charges namely point, infinitely long line and uniformly charged ring. The before and after effects of the visuohaptic intervention are compared, wherein the intervention includes instructional scaffolding. Three single-group studies were conducted to investigate the effect among three different populations: (a) Undergraduate engineering students, (b) Undergraduate technology students and (c) Undergraduate engineering technology students from a different demographic setting. The findings from the three studies suggests that the haptic modality intervention provides beneficial effects by allowing students to improve their conceptual understanding of electric field for distributed charges, although students from groups (b) and (c) showed a statistically significant increase in the conceptual understanding. The findings also indicate a positive learning perception among all the three groups

Informational variables for basketball dribble control

Analyzing the influence of perceptual variables on basketball dribbling motor control can provide precise information on how this kind of control operates. To assess these variables contribution to the motor control process two groups were tested (i.e. amateurs and professionals), with distinct levels of experience under the perceptual occlusion paradigm, in a static dribble task (i.e., no overall displacement of the individual). Auditory and peripheral vision were chosen as the perceptual variables to be occluded for this study because both, often, are constrained in a competitive setup. The main goal of the thesis was identifying how joints adapted their behavior to each of these two occlusions, when presented alone or together, allowing us to establish an adaptive profile for each group. To do so, tools of non linear (i.e. such as correlation dimension, approximate entropy and Lyapunov exponent), synergistic (i.e. uncontrolled manifold) and dissimilarity analysis (i.e. Procrustes) were used in order to design behavior adaptation profiles for the upper limb main joints when exposed to occlusion phenomena. Overall auditory occlusion had no significant influence in the chosen variables. Even when used jointly with peripheral vision occlusion no cumulative effects in adaptive behavior was observed. However, peripheral vision occlusion lead to some adaptive behaviors throughout both groups that made us conclude the following: 1) wrist position stability is a performance indicator and represents a superior adaptive mechanism; 2) lateral elbow variability and horizontal shoulder variability (i.e. anterior-posterior and lateral) are performance factors allowing the system to be more flexible, thus improving its ability to adapt to constraints; 3) shoulder and elbow angles form a synergy between them in order to stabilize wrist vertical position; 4) the aforementioned synergy is not constant throughout the whole cycle; 5) peripheral vision occlusion disturbs amateurs dribbling performance almost four times more than it does to professionalsA análise das variáveis preceptivas para o controlo motor do drible pode fornecer indicadores objetivos sobre o funcionamento deste controlo. Para avaliar a contribuição de cada uma das variáveis testámos dois grupos com níveis de experiências distintos (i.e., amadores e profissionais) sob o paradigma da oclusão numa tarefa de drible estático (i.e., sem deslocamento do individuo). As variáveis percetivas escolhidas foram a visão periférica e a audição devido aos constrangimentos que os atletas encontram frequentemente em ambiente competitivo. O objetivo foi identificarmos as adaptações que a oclusão provoca, separadamente ou em conjunto, num conjunto de variáveis de natureza articular, podendo posteriormente estabelecer um perfil adaptativo para cada um dos grupos de experiência. Usámos ferramentas de análise não-linear (i.e., dimensão correlacionada, entropia aproximada e expoente de Lyapunov), análise de sinergias (i.e., uncontrolled manifold) e análise de dissemelhança (i.e. Procrustes) para traçar um perfil de comportamento das principais articulações do membro superior quando exposta a fenómenos de oclusão. A oclusão da audição não teve influências significativas nas variáveis analisadas, mesmo quando usada juntamente com a oclusão da visão periférica efeitos adaptativos cumulativos não foram observados. No entanto, através dos comportamentos adaptativos provocados pela oclusão da visão periférica várias conclusões emergiram da nossa análise: 1) a estabilidade da posição do punho é um indicador de performance que representa um melhor comportamento adaptativo; 2) a variabilidade da posição lateral do cotovelo e da posição horizontal do ombro (i.e. ântero-posterior e lateral) é um fator de performance e carateriza uma melhor flexibilidade de adaptação aos constrangimentos; 3) o ângulo do ombro e do cotovelo têm um comportamento sinérgico entre si para estabilizar a posição vertical do punho na execução do drible; 4) a sinergia entre o ângulo do ombro e o cotovelo não é constante durante todo o ciclo de execução; 5) a oclusão da visão periférica perturba a performance no drible nos amadores quase quatro vezes mais que o verificado nos profissionai

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility