By Topic

EuroHaptics conference, 2009 and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. World Haptics 2009. Third Joint

Date 18-20 March 2009

Filter Results

Displaying Results 1 - 25 of 133
  • Message from the Conference Editorial Board

    Publication Year: 2009 , Page(s): i
    Save to Project icon | Request Permissions | PDF file iconPDF (38 KB)  
    Freely Available from IEEE
  • Message from the chairs

    Publication Year: 2009 , Page(s): ii
    Save to Project icon | Request Permissions | PDF file iconPDF (143 KB)  
    Freely Available from IEEE
  • Committee

    Publication Year: 2009 , Page(s): iii - vi
    Save to Project icon | Request Permissions | PDF file iconPDF (49 KB)  
    Freely Available from IEEE
  • Message from the Chair of EuroHaptics

    Publication Year: 2009 , Page(s): vii
    Save to Project icon | Request Permissions | PDF file iconPDF (105 KB)  
    Freely Available from IEEE
  • Message from the General Chair

    Publication Year: 2009 , Page(s): viii
    Save to Project icon | Request Permissions | PDF file iconPDF (41 KB)  
    Freely Available from IEEE
  • Technical Committee

    Publication Year: 2009 , Page(s): ix
    Save to Project icon | Request Permissions | PDF file iconPDF (110 KB)  
    Freely Available from IEEE
  • Table of contents

    Publication Year: 2009 , Page(s): x - xxi
    Save to Project icon | Request Permissions | PDF file iconPDF (147 KB)  
    Freely Available from IEEE
  • Control of an actuated car door providing outstanding haptic interaction

    Publication Year: 2009 , Page(s): 314 - 319
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (317 KB) |  | HTML iconHTML  

    Actuated car doors are a promising way to increase the convenience of access to cars. In this paper, an advanced door concept which can easily be integrated into conventional car doors is presented. Using a linear, non-backdrivable actuator and various sensors, both automatic and manual door operations can be realized. The principal part is the realization of a high-quality haptic interaction of the car door for the manual operation. We implemented and tested four different impedance control schemes, of which impedance control with actuator force feedback performed best. This control scheme was subsequently used to haptically render different supportive dynamics and effects. An experimental evaluation with 16 participants revealed a predominant approval of the haptic sensation of the actuated car door. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The role of item fixation in haptic search

    Publication Year: 2009 , Page(s): 417 - 421
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (731 KB) |  | HTML iconHTML  

    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 no attention yet. In this study we focus on the importance of freedom to manipulate the objects in the hand for three-dimensional shape perception. Furthermore, we investigate differences in detection speed for different positions in the grasping hand. Subjects were asked to search for a cube among spheres or for a sphere among cubes. Response times were measured for different locations of target shape in the hand. Also, the way in which the items were fixed was varied from allowing small displacements and rotation of the shapes to rigidly fixed. There were only differences in search times between the different positions in the hand, when the centre item was difficult to access because of the surrounding items. Finally, we show that search was faster when the items were rigidly fixed than when displacement and rotation was possible. This shows that more exploratory freedom does not necessarily make search for a three-dimensional shape faster. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Remote dynamic proxies for wave-based peer-to-peer haptic interaction

    Publication Year: 2009 , Page(s): 553 - 558
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (751 KB) |  | HTML iconHTML  

    This paper introduces a distributed haptic control architecture that can render direct interaction between users in addition to cooperative manipulation of virtual objects. The proposed architecture integrates remote dynamic proxies and peer-to-peer wave-based communications. Remote dynamic proxies are avatars of users at peer sites with motion governed by second order dynamics laws. They render physically-based motion of the distant users in the presence of update discontinuities caused by packet transmission limitations. They also enable users to touch their far away peers directly. The remote dynamic proxies are integrated with peer-to-peer wave-based communications by using wave variable controllers to connect the distributed copies of the shared virtual object, and to connect the users to their remote dynamic proxies. The proposed distributed control architecture is compared via experiments to peer-to-peer haptic cooperation with wave variable time delay compensation. The results illustrate that remote dynamic proxies with wave-based communications: (1) improve position coherency between the distributed copies of the shared virtual object; (2) render mass more faithfully in the presence of network delay; and (3) permit users to interact with each other directly in addition to enabling them to cooperatively manipulate the shared virtual object. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Haptic stiffness identification by veterinarians and novices: A comparison

    Publication Year: 2009 , Page(s): 646 - 651
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (567 KB) |  | HTML iconHTML  

    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 surfaces with 5 levels of stiffness within a ldquoclinically relevantrdquo range of 0.2 - 0.5 N/mm. The results from 12 veterinarians and 14 veterinary students show that the veterinarians performed significantly better than the students (p Lt 0.001). The mean information transfer was 0.97 bits (almost 2 perfectly-identifiable stiffness levels) for the veterinarians and 0.58 bits (1 correctly-identified stiffness level) for the students. However, neither group was able to reliably identify more than 2 levels of stiffness, indicating that the success of veterinarians in clinical practice probably relies on additional properties such as size, shape and texture. Our findings suggest that stiffness perception in the context of veterinary medicine is a learned clinical skill. Quantifying expert ability will help inform teaching methods and set targets for students. Similar psychophysical methods can also be used to monitor student performance throughout the learning process. Future work will examine the contributions of other object properties as well as motor strategies to palpation performance. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Maneuverability of master control devices considering the musculo-skeletal model of an operator

    Publication Year: 2009 , Page(s): 57 - 62
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1172 KB) |  | HTML iconHTML  

    In this paper, maneuverability measure of master control devices considering the musculo-skeletal model of operators is proposed. The original maneuverability measure of master arms considering the operator dynamics is extended by introducing a muscle tension space instead of the joint torque space of an operator so that the maneuverability is evaluated under a constant muscle stress condition which is related to muscle fatigue. Unidirectionality of muscle tension forces as well as the gravity effects acting on the master device and the operator arm are explicitly considered to get a correct evaluation. As a numerical example, the effect of a movable armrest installed on a master arm is evaluated based on the proposed measure. It is shown that the armrest is effective to reduce muscle fatigue by not only lowering the gravity loads for the operator but also reducing the gripping force necessary to maneuver the device. Experiments are also conducted to verify the result of this numerical example. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Development of tremor-suppression filter for meal-assist robot

    Publication Year: 2009 , Page(s): 238 - 243
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1127 KB) |  | HTML iconHTML  

    A robot that supports independent living by assisting with eating and other activities involving the use of the hand using the operator's own hand would be helpful for people suffering from tremors of the hand or any other body part. In this study, the proposed adaptive filter estimates tremor frequency with a time-varying property and individual differences online, and insulates the voluntary motion signal from the sensor signal containing tremor components. As a result, the developed human-machine interface makes it possible for the person with a tremor to manipulate the supporting robot without causing operability to deteriorate and without hazards due to improper operation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Position and force augmentation in a telepresence system and their effects on perceived realism

    Publication Year: 2009 , Page(s): 226 - 231
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    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 of a psychophysical experiment, which was designed to evaluate the effects of the assistance functions on perceived realism. As a result, the position assistance can increase stability and safety without negatively affecting transparency, and the force assistance can even increase the feeling of presence under certain conditions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Communication of direction through lateral skin stretch at the fingertip

    Publication Year: 2009 , Page(s): 172 - 177
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1534 KB) |  | HTML iconHTML  

    A variety of tasks could benefit from the availability of direction cues that do not rely on vision or sound. Skin stretch has been found to be a reliable means of communicating direction and has potential to be rendered by a compact device. We have conducted experiments exploring the use of lateral skin stretch at the fingertip to communicate direction. A small rubber cylinder was pressed against a subject's fingertip and moved at constant speed to stretch the skin of the fingerpad. The skin was stretched with a range of displacements (0.05 mm-1 mm) and speeds (0.5 mm/s-4 mm/s). Subjects were asked to respond with the direction of the skin stretch, choosing from 4 directions, each separated by 90 degrees. It was found that subjects could perceive skin stretch direction with as little as 0.05 mm of stretch. Direction detection accuracy was found to be dependent upon both the speed and total displacement of the skin stretch. Higher speeds and larger displacements resulted in greater accuracy. High accuracy rates, greater than 95%, were observed with as little as 0.2 mm of skin stretch and at speeds as slow as 2 mm/s. Accuracy was also found to vary with the direction of the stimulus. This preliminary information will be used to inform the design of a miniature tactile display suitable for use in hand-held electronics. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance improvement with haptic assistance: A quantitative assessment

    Publication Year: 2009 , Page(s): 511 - 516
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (451 KB) |  | HTML iconHTML  

    We measure the performance improvement that force feedback can provide in a virtual environment, through three experiments with, and without the assistance of haptic guidance. Performance measurements were undertaken with haptic, visual and auditory feedback alternatives. The first task investigated the use of haptic guidance mimicking reality, in the form of a simulated touchable surface of an object. The second investigated haptic guidance which waxed and waned as the user violated program rules by varying amounts. The third experiment investigated whether this latter artificial guidance would inhibit the user's free will by taking control out of their hands. The results showed that a significant improvement in both accuracy and speed was achieved by the introduction of haptics in all experiments. It also found that the haptic guidance did not take control away from the user and that they had significantly more control than with conventional warning methods. These experiments were not aimed at learning, or retention of skill, but on using haptics as an aid to improve performance during a task. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Inverse piano technique for studying finger interaction during pressing tasks

    Publication Year: 2009 , Page(s): 395 - 396
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (267 KB) |  | HTML iconHTML  

    When a person moves or presses with an individual finger other fingers also produce a force (Kilbreath and Gandevia 1994; Li et al. 2004; Zatsiorsky et al. 2000). Several factors are known to contribute to this response: (1) peripheral mechanical coupling, (2) multi-digit motor units, and (3) diverging central commands. This phenomenon, known as enslaving, has traditionally been studied in isometric pressing tasks. The purpose of this project was to build a device, an Inverse Piano (IP), to study finger interaction in non-isometric pressing tasks. The IP allows for fingers to be unexpectedly raised or lowered during pressing tasks. Fingers are perturbed by linear motors located directly under uni-dimensional force sensors, which serve as the "piano keys". Motors are triggered using National Instruments Lab VIEW. This allows key position and finger force data to be recorded simultaneously. The IP makes possible the studying of several factors on the finger force outcome and coordination. In particular, the following factors can be explored: (a) Finger combination. There are 15 combinations of the key manipulation: four 1-finger tasks (I, M, R, L, where the letters designate the index, middle, ring, and little finger respectively); six 2-finger tasks (IM, IR, IL, MR, ML, RL); four 3-finger tasks (IMR, IML, IRL, MRL) and one 4-finger task (IMRL). (b) Predictability of the key raising. The options are innumerable but can be roughly classified into three groups: (1) both the sequence and time intervals are unknown to the subjects; (2) the sequence is known but the time intervals are unknown; and (3) both the sequence and time intervals are known in advance, (c) Amplitude of key movement. The IP is capable of displacing fingers up to 2 cm, in increments less than 1 mm. (d) The speed of key movement. The IP can vary key movement rates of between 2 mm/s to 4,687 mm/s. (e) Resistance of the keys to the external force. The resistance can mimic different mechanical properties,- - e.g. elastic resistance which is proportional to the key displacement, damping resistance proportional to the speed, dry friction, etc. The magnitude of the resistance, e.g. 'stiffness', can also be varied, (f) Feedback with various options: (1) visual feedback on the computer screen, the subject can also see his/her hand; (2) no visual feedback on the screen, however the subject can see his/her hand; and (3) no feedback on the screen, the subject cannot see his/her hand. Thus far experimentation using IP has only investigated effects of varying magnitude of displacement. The IP also has the potential to be utilized as a rehabilitation device for patients suffering a loss of dexterity and finger strength. It is possible for a variety of programs to be created that would train both finger independence and strength. One such program is illustrated in figure 1 where a target force is given on a computer screen and the patient would be instructed to match the force output of their instructed finger(s) to the target. The IP would also make it possible to give very precise quantitative feedback, on various measures of performance, to the clinician as opposed to qualitative feedback that is the staple of most current methods of rehabilitation. The purpose of the demonstration is to show the capabilities of the IP as both a research and rehabilitation device. Several custom programs will be written that allow for easy manipulation of variables (i.e. key height, speed of raising, combination of keys raised, target force feedback, etc) so that attendees, with both research and clinician backgrounds, can test the IP. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Compact MR-brake with serpentine flux path for haptics applications

    Publication Year: 2009 , Page(s): 91 - 96
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (646 KB) |  | HTML iconHTML  

    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 reduce off-state friction. Experimental results showed that, when compared to a commercial MR brake, our 33% smaller prototype MR-brake could generate 2.7 times more torque (10.9 Nm). A 1-DOF haptic interface employing the brake enabled crisp virtual wall collision simulations. Significant reduction in the off-state torque was obtained by applying a reverse current pulse to collapse a residual magnetic field in the brake. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An energy bounding approach for directional transparency in multiple degree-of-freedom haptic interaction

    Publication Year: 2009 , Page(s): 320 - 325
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1391 KB) |  | HTML iconHTML  

    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 orthogonal coordinate. For guaranteeing stability in each orthogonal coordinate, the EBA is applied. For multiple-dof haptic interaction, however, the EBA in each coordinate may cause a problem that the direction of the rendered force vector is distorted. This problem can easily be solved by projecting the direction of the rendered force vector on its original direction. The validity of the proposed algorithm is shown by some experiments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Discrimination of thermal diffusivity

    Publication Year: 2009 , Page(s): 635 - 639
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (530 KB) |  | HTML iconHTML  

    Materials such as wood or metal which are at equal temperatures are perceived to be of different ldquocoldnessrdquo due to differences in thermal properties, such as the thermal diffusivity. The thermal diffusivity of a material is a parameter that controls the rate with which heat is extracted from the hand when it touches an object of that material. This rate of heat extraction is an important cue for distinguishing materials and recognising objects by means of touch. We have measured the ability of human observers to discriminate between different rates of heat extraction. This was done using a device that displayed different transient temperature profiles to the finger. In different conditions, subjects were repeatedly asked to select the faster-cooling of two stimuli. The discrimination threshold was around 43% of the extraction rate. A rate that was twice as slow also yielded twice the absolute discrimination threshold. When we halved the temperature difference between beginning and end of the stimulus, the threshold did not change as much. This shows that subjects can use the rate of heat extraction as a cue and that they can discriminate between materials if their thermal diffusivities are at least 43% apart. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Method for presenting virtual objects to multiple fingers on two-hands using multiple single-point haptic devices

    Publication Year: 2009 , Page(s): 244 - 249
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (752 KB) |  | HTML iconHTML  

    In this paper, we discuss a method for presenting virtual objects to multiple fingers on both hands using multiple single-point haptic devices operating over a network. We evaluated the effect of the number of fingers used on ability to recognize shapes using this system. The experimental results suggest that the number of contact points do not sufficiently improve the ability to recognize shapes, and the method used for recognizing object shape is rather different between using one finger and using multiple fingers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Perceptual coding of haptic data in time-delayed teleoperation

    Publication Year: 2009 , Page(s): 208 - 213
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (375 KB) |  | HTML iconHTML  

    In telepresence and teleaction systems the haptic communication channel plays a central role. As it closes a global control loop any introduced communication delay possibly destabilizes the system and impairs the performance. The scattering theory is known to solve these stability issues by transmitting wave variables instead of haptic signals, i.e. force and velocity, over the communication channel. For stability and performance additionally high packet rates are required stressing the underlying network resources. Perceptual coding techniques of haptic signals, such as the Weber-inspired deadband approach, are known to successfully reduce the packet rate on the haptic channel. However, as wave variables do not directly represent haptic information but a linear transformation of both signals, perceptual coding is not directly applicable anymore. In this paper, we present a novel control scheme as well as a modification of the deadband approach to take advantage of the stabilization ability of the wave variables while allowing perceptual coding on the communication channel. Simulation results and comparison with the wave variables architecture indicate improved data compression for same degree of transparency for purely stiff as well as free environments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Five-fingered haptic interface robot: HIRO III

    Publication Year: 2009 , Page(s): 458 - 463
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1929 KB) |  | HTML iconHTML  

    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 and can provide multipoint contact between the user and a virtual environment. However, the following problems peculiar to a multi-DOF robot have resulted: a backlash, a large amount of friction, many motors, and many sensors. In order to solve these problems, a new mechanism and a wire-saving control system have been designed and developed. Furthermore, experiments in both free space and constraint space have been carried out. In comparison with the previous HIRO, the force errors in free space and in constraint space have been reduced to 30% and 57%, respectively. These results show a high-precision force representation and the great potential of HIRO III. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Haptic rendering of complex deformations through handle-space force linearization

    Publication Year: 2009 , Page(s): 422 - 427
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (644 KB) |  | HTML iconHTML  

    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 haptically manipulated may have many degrees of freedom, but haptic interaction is often implemented in practice through low-dimensional force-feedback devices. We exploit the low-dimensional domain of the interaction for devising a novel linear approximation of interaction forces that can be efficiently evaluated at force-update rates. Moreover, our linearized force model is time-implicit, which implies that it accounts for contact constraints and the internal dynamics of deforming objects. In this paper we show examples of haptic interaction in complex situations such as large deformations, collision between deformable objects (with friction), or even self-collision. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Computationally efficient techniques for data-driven haptic rendering

    Publication Year: 2009 , Page(s): 39 - 44
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (993 KB) |  | HTML iconHTML  

    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 high accuracy with respect to the just noticeable difference for forces. To this end, we performed a user study to estimate this perception threshold. The threshold is used to assess the final error in the rendered forces as well as for the parameter reduction process. Comparison with measured data from real object interactions confirms the accuracy of our method and highlights the reduced computational effort. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.