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The main result of this paper is a new model based on homotopy switching between intrinsically distinct controllers that encompass most behaviors encountered in dyadic haptic collaborative tasks. The basic idea is to switch continuously between two distinct extreme behaviors (leader and follower) for each individual, which creates an implicit bilateral coupling within the dyad. The physical collaborative...
We consider the following problem in haptics: information update from the virtual world is slow w.r.t. the local servo-loop rate of the haptic device, and the information transmission/update between the haptic device and the virtual world is of variable rate and/or asynchronous. For this, we propose a novel control framework, that, by relying on our recently proposed passive set-position modulation...
The force-update-rate requirements of transparent rendering of virtual environments are in conflict with the computational cost required for computing complex interactions between deforming objects. In this paper we introduce a novel method for satisfying high force update rates with deformable objects, yet retaining the visual quality of complex deformations and interactions. The objects that are...
This paper presents an energy bounding approach (EBA) to enhance directional transparency while guaranteeing stability for multiple degree-of-freedom (DOF) haptic interaction. It was observed that the passivity condition for multiple ports may lead to some oscillations in some coordinate directions even though total energy is positive. The passivity condition, therefore, needs to be applied to each...
Several causes of instabilities in the interaction of users with actively controlled haptic devices, notably sampling effects, sensor quantization, and hardware nonlinearities, have been identified and analyzed in prior work. However, certain instabilities may occur that cannot be attributed to these hardware limitations. The problem becomes acute when rendering passive virtual environments which...
This paper presents the design, fabrication, control and testing of the third generation prototype of a novel, one degree of freedom (DOF) variable resistance hand device (VRHD) that was designed for isotonic, isokinetic, and variable resistance grasp and release exercises. Its principle functionality is derived from an electro-rheological fluid based controllable damper that allows continuously variable...
The present work focuses on perceptual control of haptic manipulation during high frequency interaction with mobile objects. In particular in this work we focused on the analysis of the control and perceptual issues in the throwing and catching in juggling. A training multimodal system that exploits the concepts of co-located visuo-haptic feedback and encountered interfaces was implemented. Using...
This paper investigates the benefits of haptics-based interaction for performing assembly-related tasks in a virtual environment. The research examines the context in which haptic feedback affects user performance and identifies assembly operations that are influenced. Forty participants completed three experiments relevant to virtual assembly: weight discrimination, part positioning, and manual assembly...
Recent findings have shown that humans can adapt their internal control model to account for the changing dynamics of systems they manipulate. In this paper, we explore the effects of magnitude and phase cues on human motor adaptation. In our experiments, participants excite virtual second-order systems at resonance via a two-degree of freedom haptic interface, with visual and visual plus haptic feedback...
Enclosing objects in the hand is a common and efficient way of haptic exploration. Recently, the importance of grasping for more realistic haptic perception of virtual objects has been recognised in haptic interface design. While several studies on haptic perception have addressed haptic exploration of a single object, perception of several objects grasped together in the hand has received almost...
In order to enable intuitive physical interaction with autonomous robots as well as in collaborative multi-user virtual reality and tele-operation systems a deep understanding of human-human haptic interaction is required. In this paper the effect of haptic interaction in single and dyadic conditions is investigated. Furthermore, an energy-based framework suitable for the analysis of the underlying...
The following topics are dealt with: tactile displays; haptic modelling and rendering; collaboration, dynamics and control; haptic device design; perception; haptically-enhanced applications; telemanipulation and telepresence; human performance; and tactile modeling.
Data-driven haptic rendering requires processing of raw recorded signals, which leads to high computational effort for large datasets. To achieve real-time performance, one possibility is to reduce the parameter space of the employed interpolation technique, which generally decreases the accuracy in the rendering. In this paper, we propose a method for guiding this parameter reduction to maintain...
This paper presents the design and characteristics of a five-fingered haptic interface robot: HIRO III. The aim of the paper is to provide a high-precision force representation at the five human fingertips. HIRO III consists of a 15-degree-of-freedom (DOF) haptic hand, a 6 DOF interface arm and a control system. The haptic interface, which consists of a robot arm and hand, can be used in a large workspace...
Figure copying is a complex visuo-motor skill that uses aspects of vision and memory to guide precisely directed action. Previous studies have shown that explicit visual training improves the copying abilities of young children. This study considers training in a haptic virtual environment as a method to improve copying abilities in people who show weak performance in such tasks, namely normally developing...
For realizing a tactile display for a handheld device, active touch movement should be represented on a small interface. We propose the addition of a tactile feedback mechanism for a pointing-stick-type (PS) input device. In this study, we describe a method for enabling virtual active touch with a cursor on the screen operated by the PS-type tactile interface without actual touch movement. First,...
This research explores a new approach to shape the magnetic flux path in a MR brake. Magnetically conductive and non-conductive elements were stacked to weave the magnetic flux through the rotor and the outer shell of the brake. This approach enabled design of a more compact and powerful MR brake. In addition, a ferro-fluidic sealing technique was developed to prevent the fluid from leaking and to...
Haptic assistance functions for a telepresence system are presented and assessed. These assistance functions are based on the augmentation of exchanged position and force data, and they are intended to increase the transparency of the telepresence system while maintaining stability. We present the concept and implementation of different assistance functions. Furthermore, we show the setup and results...
Palpation is important in both veterinary and medical health professions. It is however difficult to learn, teach and assess. More must be understood about the skills involved in palpation. The present study compares the ability of practicing veterinarians and veterinary students to identify stiffness values. An absolute identification paradigm was used where a force-feedback device rendered virtual...
Collaborative virtual environments (CVE) allow users from different geographical locations to execute a shared task by acting upon the same entities in the virtual world. Most of these environments rely on visual and auditory senses. The advances in haptic technology have opened a path for the sense of touch to be integrated into CVE. The main issue in a haptic CVE is maintaining state consistency...
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