Force Feedback Glove Research Articles

Design and development of a lightweight, low-cost cylindrical electrostatic clutch

Electrostatic clutches have the potential to enhance the functionality of actuators in the field of robotic industries, offering benefits such as heightened precision, rapid response times, and improved energy efficiency. These clutches serve as flexible, lightweight, and cost-effective mechanisms that find applications in a variety of force-dependent tasks, including robotic grippers, clamping systems, holding fixtures, lifting and hoisting equipment, and VR haptic gloves. However, incorporating these clutches into practical designs has proven to be challenging due to the inherent variability in holding forces and its range caused by the changing position of the moving electrodes and the corresponding overlapping areas. To address this issue, we propose a novel conceptual design of an electrostatic clutch that employs cylindrical electrodes. The aim of this study is to maintain a consistent friction force range by ensuring a constant overlapping area. In demonstrating the proof of concept, we delineate the design specifications for a clutch that is customized for a haptic force feedback glove. The clutch is characterized by its compact length, lightweight construction, and cost-effectiveness. Furthermore, this proposed clutch was designed with the specific intention of providing tactile force feedback by holding the fingers of users and addressing challenges related to wearability. An experiment was conducted to determine the minimum force required to perceive resistance on the finger, showcasing the clutch’s suitability for use in VR gloves. The results revealed that the average force exerted was measured at 2.8 N. The proposed clutch demonstrates the ability to hold a maximum force of 3 N at 1000 input voltage, which should maintain the allowable move length with a fixed force range. Additionally, the response time of the proposed clutch is documented to be less than 270 ms.

Challenges of controlling the rotation of virtual objects with variable grip using force-feedback gloves

Some virtual reality (VR) applications require true-to-life object manipulation, such as for training or teleoperation. We investigate an interaction technique that replicates the variable grip strength applied to a held object when using force-feedback gloves in VR. We map the exerted finger pressure to the rotational freedom of the virtual object. With a firm grip, the object’s orientation is fixed to the hand. With a loose grip, the user can allow the object to rotate freely within the hand. A user study (N = 21) showed how challenging it was for participants to control the object’s rotation with our prototype employing the SenseGlove DK1. Despite high action fidelity, the grip variability led to poorer performance and increased task load compared to the default fixed rotation. We suspect low haptic fidelity as an explanation as only kinesthetic forces but no cutaneous cues are rendered. We discuss the system design limitations and how to overcome them in future haptic interfaces for physics-based multi-finger object manipulation.

Training Induced Improvement on Human Perception of the Force Feedback Provided by A Soft Robotic Glove.

Creating haptic interface by glove-based wearable robotic system has become an increasingly interested topic in the area of human robotic interaction. Many force feedback gloves are constructed based on soft actuators. However, the recent development of haptic and force feedback technology mainly focused on the advancement of the actuating components and mechanism, and innovation of the force feedback rendering algorithms. It seems that another important part of this human-robot-interaction loop, i.e. the human factors, were understudied. Here, this study focused on the learning effect in haptic perception. We designed a pneumatic muscle-based force feedback robotic glove which can provide customized force feedback to the dorsal surface of each finger. An experiment was carried out with a specifically training procedure and evaluation on the force feedback perceptions. The results show that practice-induced improvement can be achieved by this training, allowing people have a better perception of the force feedback provided by this glove.

A Lightweight Exoskeleton Force Feedback Glove

The wearable force feedback glove provides a promising solution for enhancing immersion during teleoperation. In this study, a lightweight five-finger exoskeleton force feedback glove (EFFG) was designed, enabling driving force detection and flexible force feedback. This wireless prototype weighs only 278 g. The glove features a bionic structure and optimized linkage length to ensure operator safety while providing extensive coverage of the finger working space. Moreover, a detailed illustration of the kinematic and dynamic analyses, as well as the circuit structure, was presented. With this prototype as the basis, an isomorphic teleoperation system is designed to achieve force feedback during teleoperation. Concurrently, a driving force-based impedance controller was proposed to enable smooth and precise force feedback. Finally, the performance of the EFFG prototype was evaluated in both unconstrained and constrained environments, demonstrating that the proposed glove is lightweight, capable of detecting driving force, and provides flexible force feedback.

Five-Fingered Passive Force Feedback Glove Using a Variable Ratio Lever Mechanism

Force feedback gloves allow users to touch and manipulate virtual objects intuitively. Compared with gloves providing active feedback force, gloves with passive feedback force are promising in terms of safety and low weight, but simulating the variable stiffness of virtual objects is more challenging. Addressing this difficulty, we propose a five-fingered glove with passive force feedback employing a variable ratio lever mechanism. The stiffness of the proposed glove is tuned by changing the structural stiffness of this mechanism rather than by applying torque control at each joint of the finger. The switch between free and constrained space is realized in real time by locking/unlocking the revolute joints of the glove using a servo motor. Furthermore, a predictive control mode is proposed to reduce the response time of the control system, and the actual response time is less than the limit of the delay (45 ms) that humans can perceive between visual and haptic stimuli. Experimental results show that the linear stiffness at the fingertip ranges from 0.89 to 619.89 N/m, and the maximum backdrive force of the proposed glove is less than 0.147 N.

A Three-Fingered Force Feedback Glove Using Fiber-Reinforced Soft Bending Actuators

Force feedback gloves are promising for producing immersive haptic sensations in virtual reality systems or for intuitive control of remote robots in dexterous manipulation tasks. Existing gloves mainly adopt rigid actuators. In this article, we propose a force feedback glove using pneumatically powered fiber-reinforced soft bending actuators. Based on the unilateral deformable feature of the soft actuator, a dorsal-side mounted soft-rigid linkage mechanism is proposed to produce fingertip force feedback. We incorporated and experimentally determined a positive prebending deformation of the actuator to ensure small backdrive forces for simulating free-space sensation. To enable a large workspace of the glove, the soft-rigid linkage is synthesized to ensure full open/closure of the finger without any mechanical interference. Using a modular design concept, a three-fingered glove prototype is developed with a mass of 93.7 g. Experimental results show that the glove can provide distinct force feedback between free and constrained space. For free space, the maximum backdrive force is 0.48 N, while the fingertip force reaches up to 4.09 N for simulating the constrained space. Experiments also indicate that the glove is easy to put on/off . These results illustrate the feasibility of developing light-weighted force feedback gloves using fiber-reinforced soft bending actuators.

Passive Force-Feedback Gloves With Joint-Based Variable Impedance Using Layer Jamming.

Force feedback gloves have a great potential in enhancing the fidelity of virtual reality and teleoperation systems. It is a challenge to develop multifinger and lightweight force feedback gloves. In this paper, we propose a solution using layer jamming sheet (LJS) on each finger joint. In simulating free space, the LJS is soft and easy to deform, which allows the finger joints to move freely with a small resistance force. In simulating constrained space, the LJS becomes stiff, which provides resistance torques to prevent the rotation of finger joints. Possible solutions for mounting the LJS on finger joints are investigated. Mechanical models of the LJS are derived by quantifying the relationship between the bending stiffness and the pressure, material, and geometry of the layer. Experiments are performed to characterize the mechanical behavior of the LJS actuator and to validate the performance of the different design solutions in simulating free space and constrained space. Experimental results indicate the potential of the proposed joint-based LJS-actuated approach in developing lightweight force feedback gloves.

Toward Whole-Hand Kinesthetic Feedback: A Survey of Force Feedback Gloves

Force feedback gloves have found many applications in fields such as teleoperation and virtual reality. In order to enhance the immersive feeling of interaction with remote or virtual environments, glove-like haptic devices are used, which enable users to touch and manipulate virtual objects in a more intuitive and direct way via the dexterous manipulation and sensitive perception capabilities of human hands. In this survey, we aim to identify the gaps between existing force feedback gloves and the desired ones that can provide robust and realistic sensation of the interaction with diverse virtual environments. By examining existing force feedback gloves, the pros and cons of existing design solutions to the major sub-systems including sensing, actuation, control, transmission and structure are discussed. Future research topics are put forward with design challenges being elaborated. Innovative design solutions are needed to enable the utility of wearable haptic gloves in the upcoming virtual reality era.

Design of a Lightweight Force-Feedback Glove with a Large Workspace

Abstract A wearable force-feedback glove is a promising way to enhance the immersive sensation when a user interacts with virtual objects in virtual reality scenarios. Design challenges for such a glove include allowing a large fingertip workspace, providing a desired force sensation when simulating both free- and constrained-space interactions, and ensuring a lightweight structure. In this paper, we present a force-feedback glove using a pneumatically actuated mechanism mounted on the dorsal side of the user’s hand. By means of a triple kinematic paired link with a curved sliding slot, a hybrid cam-linkage mechanism is proposed to transmit the resistance from the pneumatic piston rod to the fingertip. In order to obtain a large normal component of the feedback force on the user’s fingertip, the profile of the sliding slot was synthesized through an analysis of the force equilibrium on the triple kinematic paired link. A prototype five-fingered glove with a mass of 245 g was developed, and a wearable force-measurement system was constructed to permit the quantitative evaluation of the interaction performance in both free and constrained space. The experimental results confirm that the glove can achieve an average resistance of less than 0.1 N in free-space simulation and a maximum fingertip force of 4 N in constrained-space simulation. The experiment further confirms that this glove permits the finger to move freely to simulate typical grasping gestures.

Shared virtual environments for telerehabilitation.

Current VR telerehabilitation systems use offline remote monitoring from the clinic and patient-therapist videoconferencing. Such "store and forward" and video-based systems cannot implement medical services involving patient therapist direct interaction. Real-time telerehabilitation applications (including remote therapy) can be developed using a shared Virtual Environment (VE) architecture. We developed a two-user shared VE for hand telerehabilitation. Each site has a telerehabilitation workstation with a videocamera and a Rutgers Master II (RMII) force feedback glove. Each user can control a virtual hand and interact hapticly with virtual objects. Simulated physical interactions between therapist and patient are implemented using hand force feedback. The therapist's graphic interface contains several virtual panels, which allow control over the rehabilitation process. These controls start a videoconferencing session, collect patient data, or apply therapy. Several experimental telerehabilitation scenarios were successfully tested on a LAN. A Web-based approach to "real-time" patient telemonitoring--the monitoring portal for hand telerehabilitation--was also developed. The therapist interface is implemented as a Java3D applet that monitors patient hand movement. The monitoring portal gives real-time performance on off-the-shelf desktop workstations.

Haptic Glove with MR Brakes for Distributed Finger Force Feedback

Most existing haptic gloves are complicated user interfaces with remotely located actuators. More compact and simpler haptic gloves would greatly increase our ability to interact with virtual worlds in a more natural way. This research explored the design of a compact force feedback glove using a new finger mechanism and magnetorheological (MR) brakes as passive actuators that oppose human finger motion. The mechanism allowed for a reduction of the number of actuators and application of distributed forces at the bottom surface of user's fingers when an object was grasped in a virtual environment. The MR brakes incorporated a serpentine flux path that led to a small brake with high torque output and the elimination of remote actuation. Force analysis of the mechanism, grasping force experiments, and virtual pick-and-place experiments were done. The glove reduced task completion time by 61% and could support up to 17 N fingertip force along with 11.9 N and 18.7 N middle and proximal digit forces.

Haptic Glove With MR Brakes for Virtual Reality

Haptic gloves open up the world of force feedback by allowing the user to pick up and feel virtual objects in a natural way. In most of the existing gloves, a remote box houses a large number of actuators and sensors. Power to the glove is transmitted via cables. If the haptic gloves were smaller, lighter, and easier to use and control, they could become more common as human-machine interfaces. Recent developments show that actuators based on active fluids, such as the magnetorheological (MR) fluids, can be viable alternatives in haptics. But these devices are desk- or floor-mounted and use relatively large MR brakes. In this research, we developed a compact MR brake that is about 25 mm in diameter, weighs 84 g, and can apply up to 899 Nmiddotmm torque. The compact size was achieved by stacking steel and aluminum rings to create a serpentine flux path through the fluid. Six brakes were used to build a force feedback glove called MR glove. The glove weighs 640 g and does not require any remote actuators. Results of usability experiments showed that the MR glove improved task completion times in grasping virtual objects and could convey stiffness information to the user.

Use of Magnetorheological Fluid in a Force Feedback Glove

Magnetorheological fluid (MRF) is a smart material that has the property of changing its viscosity when exposed to a magnetic field. By placing this fluid into a sealed cylinder with an electromagnet piston as a core, a controllable resistance motion dampener can be created. A novel exoskeleton mechanical power transmission system was designed, utilizing rapid prototype parts, to transmit these resistive forces to the user's fingertips. A first iteration force feedback glove was developed and tested on human subjects for overall usability. The eventual goal of the system is to provide an alternative force producing system for exercises and rehabilitation. The entire system is lightweight, low power, and easily portable.

Guest Editorial Special Theme on Virtual Rehabilitation

The seven papers in this special section were originally presented at the International Workshop on Virtual Rehabilitation (IWVR). The selected papers cover some of the following topics: a novel magnetorheologic force feedback glove; how virtual environments can be used to help patients operate a simulated limb to interact with virtual objects; a networked textual virtual environment which can serve as an aid for patients with vision loss; the technical feasibility of teleassessments for rehabilitation; and the use of systems where virtual environments mediate training at a distance.

A Spring Model for Whole-Hand Virtual Grasping

We present a physically-based approach to grasping and manipulation of virtual objects that produces visually realistic results, addresses the problem of visual inter-penetration of hand and object models, and performs force rendering for force-feedback gloves, in a single framework. Our approach couples a simulation-controlled articulated hand model to tracked hand configuration using a system of linear and torsional virtual spring-dampers. We discuss an implementation of our approach that uses a widely available simulation tool for collision detection and response. We pictorially illustrate the resulting behavior of the virtual hand model and of grasped objects, discuss user behavior and difficulties encountered, and show that the simulation rate is sufficient for control of current force-feedback glove designs. We also present a prototype system for natural whole-hand interactions in a desktop-sized workspace.

A Spring Model for Whole-Hand Virtual Grasping

We present a physically-based approach to grasping and manipulation of virtual objects that produces visually realistic results, addresses the problem of visual inter-penetration of hand and object models, and performs force rendering for force-feedback gloves, in a single framework. Our approach couples a simulation-controlled articulated hand model to tracked hand configuration using a system of linear and torsional virtual spring-dampers. We discuss an implementation of our approach that uses a widely available simulation tool for collision detection and response. We pictorially illustrate the resulting behavior of the virtual hand model and of grasped objects, discuss user behavior and difficulties encountered, and show that the simulation rate is sufficient for control of current force-feedback glove designs. We also present a prototype system for natural whole-hand interactions in a desktop-sized workspace.

Evaluation of a Haptic Mixed Reality System for Interactions with a Virtual Control Panel

We present a haptic feedback technique that combines feedback from a portable force-feedback glove with feedback from direct contact with rigid passive objects. This approach is a haptic analogue of visual mixed reality, since it can be used to haptically combine real and virtual elements in a single display. We discuss device limitations that motivated this combined approach and summarize technological challenges encountered. We present three experiments to evaluate the approach for interactions with buttons and sliders on a virtual control panel. In our first experiment, this approach resulted in better task performance and better subjective ratings than the use of only a force-feedback glove. In our second experiment, visual feedback was degraded and the combined approach resulted in better performance than the glove-only approach and in better ratings of slider interactions than both glove-only and passive-only approaches. A third experiment allowed subjective comparison of approaches and provided additional evidence that the combined approach provides the best experience.

A Touching Sensation

This article discusses Haptics technology that is being used to train surgeons and rehabilitate patients. Haptics technology, a recent enhancement to virtual reality technology, gives users the touch and feel of simulated objects they interact with, usually through a device like a specialized mouse or a haptic glove. John Hollerbach, a computing professor and an adjunct professor of mechanical engineering at the University of Utah, says haptic devices and robotic devices share the same drawbacks, particularly involving limits to the miniaturization of motors. Haptic devices that fit the hand, like the one sold by Immersion Corp., or the force-feedback glove developed at Rutgers give the wearer a sense of touch, as if one is squeezing a ball or tracing an object. Hollerbach of the University of Utah said the future looks bright for haptics. The Rutgers ankle simulates walking over several types of terrain for patients undergoing physical therapy. Haptics can simulate assembling a part to ensure that it is designed for easy construction.

Whole-hand kinesthetic feedback and haptic perception in dextrous virtual manipulation

One of the key requirements for a Virtual Reality system is the multimodal, real-time interaction between the human operator and a computer simulated and animated environment. This paper investigates problems related particularly to the haptic interaction between the human operator and a virtual environment. The work presented here focuses on two issues: 1) the synthesis of whole-hand kinesthetic feedback, based on the application of forces (torques) on individual phalanges (joints) of the human hand, and 2) the experimental evaluation of this haptic feedback system, in terms of human haptic perception of virtual physical properties (such as the weight of a virtual manipulated object), using psychophysical methods. The proposed kinesthetic feedback methodology is based on the solution of a generalized force distribution problem for the human hand during virtual manipulation tasks. The solution is computationally efficient and has been experimentally implemented using an exoskeleton force-feedback glove. A series of experiments is reported concerning the perception of weight of manipulated virtual objects and the obtained results demonstrate the feasibility of the concept. Issues related to the use of sensory substitution techniques for the application of haptic feedback on the human hand are also discussed.

Virtual reality-enhanced stroke rehabilitation.

A personal computer (PC)-based desktop virtual reality (VR) system was developed for rehabilitating hand function in stroke patients. The system uses two input devices, a CyberGlove and a Rutgers Master II-ND (RMII) force feedback glove, allowing user interaction with a virtual environment. This consists of four rehabilitation routines, each designed to exercise one specific parameter of hand movement: range, speed, fractionation or strength. The use of performance-based target levels is designed to increase patient motivation and individualize exercise difficulty to a patient's current state. Pilot clinical trials have been performed using the above system combined with noncomputer tasks, such as pegboard insertion or tracing of two-dimensional (2-D) patterns. Three chronic stroke patients used this rehabilitation protocol daily for two weeks. Objective measurements showed that each patient showed improvement on most of the hand parameters over the course of the training. Subjective evaluation by the patients was also positive. This technical report focuses on this newly developed technology for VR rehabilitation.