Handheld Haptic Device Research Articles

A Novel Ungrounded Haptic Device for Generation and Orientation of Force and Torque Feedbacks.

To provide deeper immersion for the user in the virtual environments, both force and torque feedbacks are required rather than the mere use of visual and auditory ones. In this paper, we develop a novel propeller-based Ungrounded Handheld Haptic Device (UHHD) that delivers both force and torque feedbacks in one device to help the user experience a realistic sensation of immersion in a three-dimensional (3D) space. The proposed UHHD uses only a pair of propellers and a set of sliders to continuously generate the desired force and torque feedbacks up to 15N and 1N.m in magnitude in less than 370ms, respectively. The produced force and torque feedbacks are oriented in a desired direction using a gimbal mechanism where the propellers are mounted inside in such a way that a simple structure is obtained. These features facilitate the control of the proposed UHHD and enhance its practicality in various applications. To prove the capability of the system, we model it and elaborate on the force and torque analyses. Next, we develop a robust parallel force/position controller to tackle the structured and unstructured uncertainties. Finally, a measurement setup is manufactured to experimentally evaluate the performance of the UHHD and the controller. The implementation of the controller on the developed UHHD prototype shows that a satisfactory control performance is achievable in terms of offering the desired force and torque feedbacks.

Perception of Soft Objects in Virtual Environments Under Conflicting Visual and Haptic Cues.

In virtual/augmented/mixed reality (VR/AR/MR) applications, rendering soft virtual objects using a hand-held haptic device is challenging due to the anatomical restrictions of the hand and the ungrounded nature of the design, which affect the selection of actuators and sensors and hence limit the resolution and range of forces displayed by the device. We developed a cable-driven haptic device for rendering the net forces involved in grasping and squeezing 3D virtual compliant (soft) objects being held between the index finger and thumb only. Using the proposed device, we investigate the perception of soft objects in virtual environments. We show that the range of object stiffness that can be effectively conveyed to a user in virtual environments (VEs) can be significantly expanded by controlling the relationship between the visual and haptic cues. We propose that a single variable, named Apparent Stiffness Difference, can predict the pattern of human stiffness perception under manipulated conflict, which can be used for rendering a range of soft objects in VEs larger than what is achievable by a haptic device alone due to its physical limits.

Synthesis, dynamic modeling, prototyping and control of a handheld rotational inertia generator.

This paper explores the design and experimental validation of a three-degree-of-freedom variable inertia generator. An inertia generator is a handheld haptic device that renders a prescribed inertia. In the mechanism proposed in this paper, three-dimensional torque feedback is achieved by accelerating three pairs of flywheels mounted on orthogonal axes. While the primary objective of this work is to design an inertia generator, this study also includes developing other functionalities for the device that exploit its torque generation capabilities. These include the ability to generate a predefined torque profile and to simulate a viscous environment through damping, which are both utilized to assess the device's performance. The device proved to accurately render the necessary torques for every functionality while presenting some limitations for damping and rendering an inertia smaller than the device's inherent inertia.

Light weight Multi-layered Discal MR Fluid Clutch for Handheld Haptic Device

Light weight Multi-layered Discal MR Fluid Clutch for Handheld Haptic Device

A hand-held device with 3-DOF haptic feedback mechanism for microsurgery.

The hand-held devices have the advantages of being compact and easily integrated into surgical workflow especially for microsurgery. However, one of the technical challenges of hand-held device in microsurgery is the lack of force sensing and feedback. This paper presents a hand-held haptic device that converts imperceptible forces into human-perceptible tactile signals. It combines a force sensing tip based on fiber Bragg grating (FBG) sensors that can detect three-degrees-of-freedom (3-DOF) forces, and a haptic feedback mechanism to indicate the magnitude and direction of the forces. Experimental results demonstrate the ability to measure transverse force at the level of millinewton. User trials have been performed to validate the performance of the haptic feedback. During the phantom experiment, the transverse force was reduced with the feedback mechanism. The proposed device provides important insights into the design of hand-held device incorporating real-time force sensing and haptic feedback for microsurgery.

Haptic display for virtual reality: progress and challenges

Immersion, interaction, and imagination are three features of virtual reality (VR). Existing VR systems possess fairly realistic visual and auditory feedbacks, and however, are poor with haptic feedback, by means of which human can perceive the physical world via abundant haptic properties. Haptic display is an interface aiming to enable bilateral signal communications between human and computer, and thus to greatly enhance the immersion and interaction of VR systems. This paper surveys the paradigm shift of haptic display occurred in the past 30 years, which is classified into three stages, including desktop haptics, surface haptics, and wearable haptics. The driving forces, key technologies and typical applications in each stage are critically reviewed. Toward the future high-fidelity VR interaction, research challenges are highlighted concerning handheld haptic device, multimodal haptic device, and high fidelity haptic rendering. In the end, the importance of understanding human haptic perception for designing effective haptic devices is addressed.

Testing a Shape-Changing Haptic Navigation Device With Vision-Impaired and Sighted Audiences in an Immersive Theater Setting

Flatland was an immersive “in-the-wild” experimental theater and technology project, undertaken with the goal of developing systems that could assist “real-world” pedestrian navigation for both vision-impaired (VI) and sighted individuals, while also exploring inclusive and equivalent cultural experiences for VI and sighted audiences. A novel shape-changing handheld haptic navigation device, the “Animotus,” was developed. The device has the ability to modify its form in the user's grasp to communicate heading and proximity to navigational targets. Flatland provided a unique opportunity to comparatively study the use of novel navigation devices with a large group of individuals (79 sighted, 15 VI) who were primarily attending a theater production rather than an experimental study. In this paper, we present our findings on comparing the navigation performance (measured in terms of efficiency, average pace, and time facing targets) and opinions of VI and sighted users of the Animotus as they negotiated the 112 m2 production environment. Differences in navigation performance were nonsignificant across VI and sighted individuals and a similar range of opinions on device function and engagement spanned both groups. We believe more structured device familiarization, particularly for VI users, could improve performance and incorrect technology expectations (such as obstacle avoidance capability), which influenced overall opinion. This paper is intended to aid the development of future inclusive technologies and cultural experiences.

Development of Handheld Haptics Device for Driving System of Unmanned Underwater Vehicles

This paper presents a research aimed at illustrating hydrodynamic force impact on the orientation of a Remotely Operated Underwater Vehicle (ROV) operating underwater by providing kinaesthetic haptic feedback to its handheld steering device. To get more understanding on how this aim can be achieved, a literature review had been done on the haptic feedback which are available to ROV pilots and how it could be delivered through a handheld device. While some achievement were made in providing different cues to pilots on drag force and its influence on its speed, non-have been made to offer insight on how it had affected ROVs orientation through haptic feedback. This study found that currently available handheld haptic device, while successfully delivering tactile feedback, are not capable of providing kinaesthetic feedback at par with the grounded haptic device. To address this, a series of thrusters has been introduced as a new actuation technique in providing kinaesthetic feedback on a handheld device in all three axes. This would allow total illustration of ROV orientation through haptic feedback. This paper has summarized and discussed our findings in our literature review, followed by some details of the proposed method.

Teleoperation of Concentric Tube Robots for Skull Base Applications: Pituitary Surgery at a Distance?

Introduction: Teleoperation for surgical procedures and related activities is a long sought goal. This has become progressively within reach with advances in robotics as well as the speed of data transfer between operator and robot. Teleoperation would allow for the widespread dissemination of “expert” operations where personnel and equipment resources may be suboptimal, greatly expand access to advanced medical technology and knowledge worldwide, and present a myriad of training and other educational opportunities. Our laboratory has developed concentric tube robots for skull base surgery that has been described previously. These consist of concentric prebent nitinol tubes with various end effectors that can be precisely controlled by the operator using a hand held haptic device. In this work, the robot was used to resect a phantom pituitary tumor at a remote location (surgeon in Nashville, Tennessee, United States, robot in Chapel Hill, North Carolina, United States) using an Internet-based data link.

Design and experimental validation of planar programmable inertia generators

This paper investigates the design and experimental development of planar programmable inertia generators. An inertia generator is a hand-held haptic device that has a programmable inertia. By moving internal masses in reaction to accelerations induced by the user, the effective inertia of the device is modified in order to render a prescribed inertia. In this paper, a one-degree-of-freedom device with one internal moving mass is first proposed. The corresponding dynamic model is developed and the rendering capabilities of the device are investigated. Then, a controller is designed to produce the appropriate motion of the internal mass in reaction to the acceleration induced by the user. A prototype is presented and experimental results are discussed. A mechanical architecture is then proposed for the design of a planar three-degree-of-freedom inertia generator. The corresponding dynamic model is derived, and it is shown that the generalized inertia matrix of the proposed mechanism is always of full rank. The rendering capabilities of the device are also investigated. Finally, simulation results obtained with the three-degree-of-freedom inertia generator are reported and discussed.

Mental rotation of tactile stimuli: using directional haptic cues in mobile devices.

Haptic interfaces have the potential to enrich users' interactions with mobile devices and convey information without burdening the user's visual or auditory attention. Haptic stimuli with directional content, for example, navigational cues, may be difficult to use in handheld applications; the user's hand, where the cues are delivered, may not be aligned with the world, where the cues are to be interpreted. In such a case, the user would be required to mentally transform the stimuli between different reference frames. We examine the mental rotation of directional haptic stimuli in three experiments, investigating: 1) users' intuitive interpretation of rotated stimuli, 2) mental rotation of haptic stimuli about a single axis, and 3) rotation about multiple axes and the effects of specific hand poses and joint rotations. We conclude that directional haptic stimuli are suitable for use in mobile applications, although users do not naturally interpret rotated stimuli in any one universal way. We find evidence of cognitive processes involving the rotation of analog, spatial representations and discuss how our results fit into the larger body of mental rotation research. For small angles (e.g., less than 40 degree), these mental rotations come at little cost, but rotations with larger misalignment angles impact user performance. When considering the design of a handheld haptic device, our results indicate that hand pose must be carefully considered, as certain poses increase the difficulty of stimulus interpretation. Generally, all tested joint rotations impact task difficulty, but finger flexion and wrist rotation interact to greatly increase the cost of stimulus interpretation; such hand poses should be avoided when designing a haptic interface.