Haptic System Research Articles

Understanding the Effect of Speed on Human Emotion Perception in Mediated Social Touch Using Voice Coil Actuators

Touch as a modality in social communication has been getting more attention with recent developments in wearable technology and an increase in awareness of how limited physical contact can lead to touch starvation and feelings of depression. Although several mediated touch methods have been developed for conveying emotional support, the transfer of emotion through mediated touch has not been widely studied. This work addresses this need by exploring emotional communication through a novel wearable haptic system. The system records physical touch patterns through an array of force sensors, processes the recordings using novel gesture-based algorithms to create actuator control signals, and generates mediated social touch through an array of voice coil actuators. We conducted a human subject study (N= 20) to understand the perception and emotional components of this mediated social touch for common social touch gestures, including poking, patting, massaging, squeezing, and stroking. Our results show that the speed of the virtual gesture significantly alters the participants' ratings of valence, arousal, realism, and comfort of these gestures with increased speed producing negative emotions and decreased realism. The findings from the study will allow us to better recognize generic patterns from human mediated touch perception and determine how mediated social touch can be used to convey emotion. Our system design, signal processing methods, and results can provide guidance in future mediated social touch design.

Development of an Integrated Haptic Sensor System for Multimodal Human–Computer Interaction Using Ultrasonic Array and Cable Robot

This paper presents the design and development of a novel haptic sensor system. It integrates cable-driven force and ultrasonic tactile feedback, which can produce multimodal haptic stimuli. The sensing element includes a Leapmotion, an ultrasonic transducer array, tension sensors, and rotary encoders, which are used to capture hand posture, project tactile points, measure cable force and length, respectively. Firstly, a 6-DOF cable-driven force feedback apparatus based on parallel mechanism is designed and ultrasonic phased array is combined to form a multimodal haptic feedback system. Secondly, a multimodal haptic fusion method for cable-driven force and ultrasonic tactile is firstly proposed to invoke realistic compound haptic sensations. To enhance the rendering effects of each subsystem, admittance control is developed for a cable robot, and a new perceived magnitude model is established for ultrasound tactile rendering. A psychophysical experiment is conducted to study the perceived characteristics of multimodal haptic stimuli. To verify the proposed system, a series of experiments were carried out, whose results indicated that the system performs well at multi-property haptic rendering and confirm the accuracy and sensitive advantage of our system in virtual reality applications. The results of our study indicate that this device has great application potential in human-computer interaction.

Homing tasks and distance matching tasks reveal different types of perceptual variables associated with perceiving self-motion during over-ground locomotion.

Self-motion perception refers to the ability to perceive how the body is moving through the environment. Perception of self-motion has been shown to depend upon the locomotor action patterns used to move the body through the environment. Two separate lines of enquiry have led to the establishment of two distinct theories regarding this effect. One theory has proposed that distances travelled during locomotion are perceived via higher order perceptual variables detected by the haptic perceptual system. This theory proposes that two higher order haptic perceptual variables exist, and that the implication of one of these variables depends upon the type of gait pattern that is used. A second theory proposes that self-motion is perceived via a higher order perceptual variable termed multimodally specified energy expenditure (MSEE). This theory proposes that the effect of locomotor actions patterns upon self-motion perception is related to changes in the metabolic cost of locomotion per unit of perceptually specified traversed distance. Here, we test the hypothesis that the development of these distinct theories is the result of different choices in methodology. The theory of gait type has been developed based largely on the results of homing tasks, whereas the effect of MSEE has been developed based on the results of distance matching tasks. Here we test the hypothesis that the seemly innocuous change in experimental design from using a homing task to using a distance matching task changes the type of perceptual variables implicated in self-motion perception. To test this hypothesis, we closely replicated a recent study of the effect of gait type in all details bar one-we investigated a distance matching task rather than a homing task. As hypothesized, this change yielded results consistent with the predictions of MSEE, and distinct from gait type. We further show that, unlike the effect of gait type, the effect of MSEE is unaffected by the availability of vision. In sum, our findings support the existence of two distinct types of higher order perceptual variables in self-motion perception. We discuss the roles of these two types of perceptual variables in supporting effective human wayfinding.

Vibrating Tilt Platform Enhancing Immersive Experience in VR

One of the disadvantages of virtual reality systems of the past was the fact that they had visual-only interfaces. However, with the development of haptic technology, peripheral solutions to enhance the VR experience are gaining momentum, and many haptic systems are being developed for deepening VR immersion. This paper deals with the concept of a vibrating tilt platform allowing the change of three angles of inclination to thus reinforce the VR experience. The proposed system is flexible and adaptable to different sports, health, and education applications. In this paper, we present the mechanical and mechatronics aspects of the platform and usability testing results based on an immersive geological experience application. The first tests were studied in terms of the cyber sickness, perceived realism, and anxiety through both subjective (questionnaires) and objective (electroencephalogram) measurements. The results indicate that our platform increased anxiety levels and was perceived as realistic. Adding vibrations and tilting had a considerable impact on the immersion level and brain activity.

Haptic Teleoperation of Impact Hammers in Underground Mining

Impact hammers are used to reduce the size of blasted ore in mining operations. In underground mines, tele-operated impact hammers are used to reduce the size of boulders placed on the orepass’s grizzlies. An impact hammer consists of a hydraulic arm with 4 degrees of freedom, powered with a hydraulic impact hammer as an end-effector. The tele-operation of impact hammers is difficult due to the latency of communications, the poor visibility of the environment, and the used 2D interfaces. This may result in a collision with the hammer and the infrastructure, idle strokes, and non-optimal operation. To address these issues, this paper proposes the haptic tele-operation of impact hammers. The proposed haptic tele-operation system is based on a 3D model of the environment, which is used to estimate repulsion forces that are transferred to the operator via a haptic device, so that the hammer does not collide with the structures of the mine. The system also allows identifying the oversized boulders deposited on the grizzly and notifying the operator every time the orepass is blocked, as well as providing different 3D views of the environment. A proof of concept is presented using a scaled setup, where it is validated that the use of the proposed system allows for providing a better and more efficient tele-operation experience.

Modeling and analysis of driver behaviour under shared control through weighted visual and haptic guidance

Driver–automation shared control through haptic steering is developed to reduce the workload of drivers while keeping them in the control loop. For the optimum design of a haptic steering system, an understanding of driver behaviour based on measurements and modeling is crucial early in the development process. This paper aims to propose a driver model using a weighting process of visual guidance from the road ahead and haptic guidance from a steering system for a lane-following task. The proposed weighting process describes the interaction and reliance of drivers in relation to haptic guidance steering. A driving simulator experiment is conducted to identify the model parameters for driving manually and with haptic guidance. The proposed driver model matched the driver input torque with reasonable fitness among 14 participants after considering individual differences. The validation results reveal that the output trajectory from the model effectively followed the driving course by matching the measured trajectory from the drivers. The model evaluation results reveal the potential of the proposed driver model to be applied to the design and evaluation of haptic guidance systems.

Real-Time Numerical Simulation for Accurate Soft Tissues Modeling during Haptic Interaction

The simulation of fabrics physics and its interaction with the human body has been largely studied in recent years to provide realistic-looking garments and wears specifically in the entertainment business. When the purpose of the simulation is to obtain scientific measures and detailed mechanical properties of the interaction, the underlying physical models should be enhanced to obtain better simulation accuracy increasing the modeling complexity and relaxing the simulation timing constraints to properly solve the set of equations under analysis. However, in the specific field of haptic interaction, the desiderata are to have both physical consistency and high frame rate to display stable and coherent stimuli as feedback to the user requiring a tradeoff between accuracy and real-time interaction. This work introduces a haptic system for the evaluation of the fabric hand of specific garments either existing or yet to be produced in a virtual reality simulation. The modeling is based on the co-rotational Finite Element approach that allows for large displacements but the small deformation of the elements. The proposed system can be beneficial for the fabrics industry both in the design phase or in the presentation phase, where a virtual fabric portfolio can be shown to customers around the world. Results exhibit the feasibility of high-frequency real-time simulation for haptic interaction with virtual garments employing realistic mechanical properties of the fabric materials.

Control of Haptic Systems Based on Input-to-State Stability

Discretization of signals often generates additional energy in the haptic systems, and makes them unstable. The currently popular controls based on the passivity stabilize the systems by limiting the rendered force of the haptic systems so that the generated energy from the system stays below zero. The passivity-based methods are, however, often conservative and sacrifice the performance of haptic rendering. This paper proposes a control method to adjust the change rate of the stiffness of virtual environment connected to the haptic systems to satisfy the input-to-state stability (ISS) for better stability and transparency. The ISS conditions for the systems are derived by modeling the system as a linear time-varying system. The systems become dissipative if they satisfy the ISS conditions. The generated surplus energy of the dissipative system is less than a positive finite value while maintaining stability. Since the passive system is a special case of the dissipative system, the proposed ISS-based control is less conservative than the passivity-based approaches. Performance of the proposed control is experimentally compared with the virtual coupling and the force-bounding method that are widely used passivity-based approaches. The energy generated from the system using the proposed method is positive finite whereas the generated energy using the passivity-based approaches is less than zero. This means that more energy is transferred to the operator. Increased stiffness corresponding to this additionally transferred energy can be rendered. Root-mean-square and maximum errors of the rendered forces are, therefore, reduced by at least 86 % and 50 %, respectively.

Upper-body haptic system for snake robot teleoperation in pipelines

Snake robots have shown a great potential for operations in confined workplaces that are less accessible or dangerous to human workers, such as the in-pipe inspection. However, the snake robot teleoperation remains a nontrivial task due to the unique locomotion mechanism (e.g., helical motion) and the constraints of the workplaces including the low visibility and indistinguishable features. Most snake robot feedback systems are based on the live camera view only. It is hard for the human operator to develop a correct spatial understanding of the remote workplace, leading to problems such as disorientation and motion sickness in snake robot teleoperation. This study designs and evaluates an innovative haptic assistant system for snake robot teleoperation in the in-pipe inspection. An upper-body haptic suit with 40 vibrators on both the front and back sides of the human operator was developed to generate haptic feedback corresponding to the bottom and up sides of the snake robot, transferring the egocentric sensation of the snake robot to the human operator. A human-subject experiment (n = 31) was performed to evaluate the efficacy of the developed system. The results indicate that the proposed haptic assistant system outperformed other feedback systems in terms of both task performance and subjective workload and motion sickness evaluations. It inspires new control and feedback designs for the future snake robot in industrial operations.

PSO-SVM-based novel haptic interface controller design

The key performance issues in the haptic system are stability and transparency. A system's stability, is defined as minimum oscillations and vibration in the output response as well as in the device itself, whereas transparency is defined as minimum error between the applied force or velocity and executed in the virtual environment (VE) of haptic system. Here, when we control the stability of the system, transparency gets hampered and vice-versa. To overcome this problem, a novel optimal haptic interface controller (HIC) has been designed using modern techniques (neural network, support vector machine, and PSO optimised SVM). This optimal HIC employs the input force provided by the user and the feedback force from the haptic device. The error between the applied force and the feedback force should be minimised to maximise transparency. Moreover, there are always some differences between the theoretical model and the physical model. To ensure the designed controller works in the physical device, an effort also has been made to accommodate the uncertainty and delay, which makes the major difference between simulated and physical models. The results obtained using optimal HIC have been compared with the conventional method, which shows improvement in transparency.

Modelling the compression of a soft ellipsoid fingertip.

A purely mechanical-driven haptic feedback system was developed for amputees by [G. Shi et al., IEEE Trans. Haptics, 2020, 13, 204-210]. The fingertip ellipsoid modulates the compression force and transmits it to the feedback actuator when the finger interacts with an object. In this paper, the haptic feedback system has been modelled using finite deformation theory. For the ellipsoid fingertip, the compression behaviour between two rigid, flat surfaces has been studied and can predict the force-indentation trend and deformed shape of the membrane with the contact area. For the feedback actuator, the model for the flat membrane is developed with elastic theory, in which the deformation resulting in contact area increase has been studied. The model has been validated with experimental results, which consists of the fingertip ellipsoid membrane being compressed by a rigid surface and the feedback actuator being pressurised. The results of force-indentation, pressure-indentation and the deformation of the membrane from ellipsoid modelling lay within the experimental data and fit the non-linear trend well. The results from modelling the feedback actuator have the same trend as the experimental data in the force-pressure relationship. The haptic feedback system is consistent as a functional tactile sensor after validation. We present the modelling and validation of the proposed model for the mechanical driven haptic feedback system.

DeviceD: Audience-dancer interaction via social media posts and wearable for haptic feedback.

The performative installation DeviceD utilizes a network of systems toward facilitating interaction between dancer, digital media, and audience. Central to the work is a wearable haptic feedback system able to wirelessly deliver vibrotactile stimuli, with the latter initiated by the audience through posting on Twitter social media platform; the system in use searches for specific mentions, hashtags, and keywords, with positive results causing the system to trigger patterns of haptic biofeedback across the wearable's four actuator motors. The system acts as the intermediator between the audience's online actions and the dancer receiving physical stimuli; the dancer interprets these biofeedback signals according to Laban's Effort movement qualities, with the interpretation informing different states of habitual and conscious choreographic performance. In this article, the authors reflect on their collaborative process while developing DeviceD alongside a multidisciplinary team of technologists, detailing their experience of refining the technology and methodology behind the work while presenting it in three different settings. A literature review is used to situate the work among contemporary research on interaction over internet and haptics in performance practice; haptic feedback devices have been widely used within artistic work for the past 25years, with more recent practice and research outputs suggesting an increased interest for haptics in the field of dance research. The authors detail both technological and performative elements making up the work, and provide a transparent evaluation of the system, as means of providing a foundation for further research on wearable haptic devices.

Toward a Digital Twin for Arthroscopic Knee Surgery: A Systematic Review

The use of digital twins to represent a product or process digitally is trending in many engineering disciplines. This term has also been recently introduced in the medical field. In arthroscopic surgery education, the paradigm shift from apprenticeship to simulation training has driven the need for better simulators, and the current focus is on improving simulators with respect to computational efficiency and system accuracy. However, expanding surgical simulations towards digital twins has not yet been explored. This paper introduces the digital twin concept for arthroscopic surgery, and explores its potential in light of the existing scientific literature. Thus, a systematic review was conducted to summarize and analyze the literature with respect to fast and robust design of an arthroscopic digital twin using patient-specific information, and methods for interactive surgical soft tissue simulation. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol with three reliable scientific search engines: IEEE Xplore, ScienceDirect and PubMed. Eighty papers were included in the review, and the extracted data included modeling methods, tissue types, constitutive behavior, computational efficiency or accuracy, hardware configuration, haptic device description, software tools, and system architectures. Considering the review, a novel macro-level conceptual arthroscopic digital twin system is presented, and the applicability of the review findings for the identified subsystems are discussed. The proposed system integrates patient-specific images, diagnostic data, intraoperative sensor data, and surgical practice as inputs, and conceptually enables surgical skills training, preoperative planning, and a database of virtual surgeries.

Multi-Cue Haptic Guidance Through Wearables for Enhancing Human Ergonomics.

Wearable haptic systems can be easily integrated with the human body and represent an effective solution for a natural and unobtrusive stimulus delivery. These characteristics can open interesting perspectives for different applications, such as haptic guidance for human ergonomics enhancement, e.g. during human-robot collaborative tasks in industrial scenarios, where the usage of the visual communication channel can be problematic. In this work, we propose a wearable multi-cue system that can be worn at the arm level on both the two upper limbs, which conveys both squeezing stimuli (provided by an armband haptic device) and vibration, to provide corrective feedback for posture balancing along the user's frontal and sagittal plane, respectively. We evaluated the effectiveness of our system in delivering directional information to control the user's center of pressure position on a balancing board. We compared the here proposed haptic guidance with visual guidance cues. Results show no statistically significant differences in terms of success rate and time for task completion for the two conditions. Furthermore, participants underwent through a Subjective Quantitative Evaluation and a NASA-TLX test, evaluating the wearable haptic system as intuitive and effective.

Preliminary testing of eye gaze interfaces for controlling a haptic system intended to support play in children with physical impairments: Attentive versus explicit interfaces.

IntroductionChildren with physical impairments may face challenges to play because of their motor impairments, which could lead to negative impacts in their development. The objective of this article was to compare two eye gaze interfaces that identified the desired toy a user wanted to reach with a haptic-enabled telerobotic system in a play activity.MethodsOne of the interfaces was an attentive user interface predicted the toy that children wanted to reach by observing where they incidentally focused their gaze. The other was an explicit eye input interface determined the toy after the child dwelled for 500 ms on a selection point. Five typically developing children, an adult with cerebral palsy (CP) and a child with CP participated in this study. They controlled the robotic system to play a whack-a-mole game.ResultsThe prediction accuracy of the attentive interface was higher than 89% in average, for all participants. All participants did the activity faster with the attentive interface than with the explicit interface.ConclusionsOverall, the attentive interface was faster and easier to use, especially for children. Children needed constant prompting and were not 100% successful at using the explicit interface.

A comparative study of tactile perception in blind and sighted subjects

Background: Blind people are underprivileged from visual experience and visual imaginary that result them to become more dependent on haptic system for the job of tactile perception. Thus, the self-guided tactile investigation in blind individuals enables them to recognize the shapes more rapidly than the sighted counterparts. Aim and Objectives: The aim of the study was to see the increased tactile perception among the blind than the blind folded sighted subjects. Materials and Methods: The study was carried out on 150 blind and 181 blindfolded sighted subjects. In this, each subject was instructed to arrange the aluminum oxide abrasive sand papers of different grit size having grade 60, 80, 100, 120, 140, 200, 240, 360, 400, and 600 from rough to smooth as fast and accurate as possible in seconds to express the functions of haptic sense. Results: The present study showed that the blind subjects had outperformed in terms of speed and accuracy of tactile perception. Conclusions: Lack of vision among blind individuals enables their brain to enhance the sense of vision and the previous tactile exposure and memories along with their regular practice enhance the touch perception in terms of speed and accuracy.

Intraoperative Data-Based Haptic Feedback for Arthroscopic Partial Meniscectomy Punch Simulation

The use of intraoperative tool-tissue interaction data for arthroscopic digital twins has the potential to enhance haptic feedback in surgical simulations. This study demonstrates the implementation of an interpolation-based method, and a Kalman filter-based method using intraoperative interaction data to provide nonlinear haptic feedback in a partial meniscectomy punch simulation. These methods were demonstrated using a novel inexpensive haptic system for simulating an arthroscopic partial meniscectomy punch. Tool-tissue interaction data were collected from a cadaveric meniscus and used for the simulations. The software, computer-aided design models, and collected data are provided open-source on GitHub. The face validity of the methods was evaluated in user studies, including six experienced orthopedic surgeons, and five non-professionals. The findings showed that experienced surgeons could distinguish between a nonlinear interpolation-based force signal, and a linear-elastic ideally-plastic finite element-based reference signal in a partial meniscectomy punch simulation. Surgeons preferred the interpolation method as a haptic rendering strategy in this study. The Kalman filter method was not as effective as interpolation in recreating nonlinear haptic feedback for the tested parameters, but demonstrated coupling of haptic force signals from intraoperative data and an idealized finite element method in a partial meniscectomy punch simulation.

Visual-haptic integration, action and embodiment in virtual reality.

The current generation of virtual reality (VR) technologies has improved substantially from legacy systems, particularly in the resolution and latency of their visual display. The presentation of haptic cues remains challenging, however, because haptic systems do not generalise well over the range of stimuli (both tactile and proprioceptive) normally present when interacting with objects in the world. This study investigated whether veridical tactile and proprioceptive cues lead to more efficient interaction with a virtual environment. Interaction in the world results in spatial and temporal correlation of tactile, proprioceptive and visual cues. When cues in VR are similarly correlated, observers experience a sense of embodiment and agency of their avatars. We investigated whether sensorimotor performance was mediated by embodiment of the avatar hands. Participants performed a Fitts' tapping task in different conditions (VR with no haptics, active haptics, passive haptics, and on a real touchscreen). The active-haptic condition provided abstract tactile cues and the passive haptic condition provided veridical tactile and proprioceptive cues. An additional (hybrid haptics) condition simulated an ideal passive haptic system. Movement efficiency (throughput) and embodiment were higher for the passive than for the active and no-haptics conditions. However, components of embodiment (perceived agency and ownership) did not predict unique variance in throughput. Improved sensorimotor performance and ratings of presence and realism support the use of passive haptics in VR environments where objects are in known and stable locations, regardless of whether performance was mediated by the sense of embodiment.

Electro-Active and Photo-Active Vanadium Oxide Nanowire Thermo-Hygroscopic Actuators for Kirigami Pop-up.

Emerging technologies such as soft robotics, active biomedical devices, wearable electronics, haptic feedback systems, and healthcare systems require high‐fidelity soft actuators showing reliable responses under multi‐stimuli. In this study, the authors report an electro‐active and photo‐active soft actuator based on a vanadium oxide nanowire (VONW) hybrid film with greatly improved actuation performances. The VONWs directly grown on a cellulose fiber network increase the surface area up to 30‐fold and boost the hydrophilicity owing to the presence of oxygen‐rich functional groups in the nanowire surfaces. Taking advantage of the high surface area and hydrophilicity of VONWs, a soft thermo‐hygroscopic VONW actuator capable of being controlled by both light and electric sources shows greatly enhanced actuation deformation by almost 70% and increased actuation speed over 3 times during natural convection cooling. Most importantly, the proposed VONW actuator exhibits a remarkably improved blocking force of up to 200% compared with a bare paper actuator under light stimulation, allowing them to realize a complex kirigami pop‐up and to accomplish repeatable shape transformation from a 2D planar surface to a 3D configuration.

Effectiveness of haptic technology in teaching urinary catheterization skill: A randomized controlled study

Haptic systems represent some of the highest levels of computer-based education technologies and enable students to learn on a higher level. The purpose of this article is to determine the effectiveness of using haptic technology in teaching urinary catheter application skill on levels of success and satisfaction about this skill. Urinary catheterization application skill was taught with the standard curriculum (demonstration on the model) to the control group, while it was taught with haptic-controlled computer-based simulation technology to the experimental group. The Checklist for Teaching Urinary Catheterization Skills mean score of the students was 58.5 ± 20.1 in the control group and 94.9 ± 3.3 in the experimental group. The catheter application skill scores and level of satisfaction about the teaching method were significantly different in favor of the experimental group (p < .001). It is recommended to popularize the use of haptic teaching technologies in nursing education.