Shape Localization and Recognition using a Magnetorheological-fluid Haptic Display

Smart materials such as magnetorheological fluids (MRF) offer an interesting technology for use in haptic displays as changes in the magnetic field are rapid, reversible, and controllable. These interfaces have been evaluated in a number of medical and surgical simulators where they can provide cues regarding the viscoelastic properties of tissues. The objective of the present set of experiments was first to determine whether a shape embedded in the MRF could be precisely localized and second whether 10 shapes rendered in a MRF haptic display could be accurately identified. It was also of interest to determine how the information transfer associated with this type of haptic display compares to that achieved using other haptic channels of communication. The overall performance of participants at identifying the shapes rendered in the MRF was good with a mean score of 73 percent correct and an Information Transfer (IT) of 2.2 bits. Participants could also localize a rigid object in the display accurately. These findings indicate that this technology has potential for use in training manual palpation skills and in exploring haptic shape perception in dynamic environments

Active-Proprioceptive-Vibrotactile and Passive-Vibrotactile Haptics for Navigation

Navigation is a complex activity and an enabling skill that humans take for granted. It is vital for humans as it fosters spatial awareness, enables exploration, facilitates efficient travel, ensures safety, supports daily activities, promotes cognitive development, and provides a sense of independence. Humans have created tools for diverse activities, including navigation. Usually, these tools for navigation are vision-based, but for situations where visual channels are obstructed, unavailable, or are to be complemented for immersion or multi-tasking, touch-based tools exist. These touch-based tools or devices are called haptic displays. Many different types of haptic displays are employed by a range of fields from telesurgery to education and navigation. In the context of navigation, certain classes of haptic displays are more popular than others, for example, passive multi-element vibrotactile haptic displays, such as haptic belts. However, certain other classes of haptic displays, such as active proprioceptive vibrotactile and passive single-element vibrotactile, may be better suited for certain practical situations and may prove to be more effective and intuitive for navigational tasks than a popular option, such as a haptic belt. However, these other classes have not been evaluated and cross-compared in the context of navigation. This research project aims to contribute towards the understanding and, consequently, the improvement of designs and user experience of navigational haptic displays by thoroughly evaluating and cross-comparing the effectiveness and intuitiveness of three classes of haptic display (passive single-element vibrotactile; passive multi-element vibrotactile; and various active proprioceptive vibrotactile) for navigation. Evaluation and cross-comparisons take into account quantitative measures, for example, accuracy, response time, number of repeats taken, experienced mental workload, and perceived usability, as well as qualitative feedback collected through informal interviews during the testing of the prototypes. Results show that the passive single-element vibrotactile and active proprioceptive vibrotactile classes can be used as effective and intuitive navigational displays. Furthermore, results shed light on the multifaceted nature of haptic displays and their impact on user performance, preferences, and experiences. Quantitative findings related to performance combined with qualitative findings emphasise that one size does not fit all, and a tailored approach is necessary to address the varying needs and preferences of users

Augmenting User Interfaces with Haptic Feedback

Computer assistive technologies have developed considerably over the past decades. Advances in computer software and hardware have provided motion-impaired operators with much greater access to computer interfaces. For people with motion impairments, the main di�culty in the communication process is the input of data into the system. For example, the use of a mouse or a keyboard demands a high level of dexterity and accuracy. Traditional input devices are designed for able-bodied users and often do not meet the needs of someone with disabilities. As the key feature of most graphical user interfaces (GUIs) is to point-and-click with a cursor this can make a computer inaccessible for many people. Human-computer interaction (HCI) is an important area of research that aims to improve communication between humans and machines. Previous studies have identi�ed haptics as a useful method for improving computer access. However, traditional haptic techniques su�er from a number of shortcomings that have hindered their inclusion with real world software. The focus of this thesis is to develop haptic rendering algorithms that will permit motion-impaired operators to use haptic assistance with existing graphical user interfaces. The main goal is to improve interaction by reducing error rates and improving targeting times. A number of novel haptic assistive techniques are presented that utilise the three degrees-of-freedom (3DOF) capabilities of modern haptic devices to produce assistance that is designed speci�- cally for motion-impaired computer users. To evaluate the e�ectiveness of the new techniques a series of point-and-click experiments were undertaken in parallel with cursor analysis to compare the levels of performance. The task required the operator to produce a prede�ned sentence on the densely populated Windows on-screen keyboard (OSK). The results of the study prove that higher performance levels can be i ii achieved using techniques that are less constricting than traditional assistance

Emulation of haptic feedback for manual interfaces

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1996.Includes bibliographical references (p. 329-339).by Karon E. MacLean.Ph.D

Multi-Finger Haptic Devices Integrating Miniature Short-Stroke Actuators

The omnipresence of electronic devices in our everyday life goes together with a trend that makes us always more immersed during their utilization. By immersion, we mean that during the development of a new product, it is more and more required to stimulate several senses of the user so as to make the product more attractive. The sense of touch does not escape the rule and is more and more considered. Definitely democratized by its integration in smart phones with touchscreens, the haptic feedback allows enhancing the human-machine interactions in many ways. For instance by improving the comfort of use of a button through the modification of its force feedback. It can also offer an interactive experience during the manipulation of digital information and even improve the communication, particularly through the internet and for blind people, with the introduction of non-verbal signals. For these reasons, the present thesis focuses on the conception of multi-finger haptic devices, a new kind of peripherals integrating multiple actuators and capable of providing a fully programmable force feedback to the user's fingers. A global methodology is presented, outlining the different constituents necessary for their conception: actuator, sensor, control, communication and software user interface. Then, generic tools corresponding to the two first elements are presented. An accurate modeling of miniature electromagnetic short-stroke actuators is made possible thanks to the combination of 3D finite element modeling (FEM) and design of experiments (DOE). The non-usual behavior of magnetic flux lines in miniature actuators with relatively large airgaps imposes to avoid simplified analytical models and to use the reliable results of finite elements. The long computation times required by 3D FEM are balanced by the use of selective DOE making the modeling methodology easily adaptable, rapid and accurate. The parametrical model of the force provided by the modeling methodology is then integrated in a full parametrical setup allowing for the optimization of the actuator force using a conventional algorithm. The advantage of the parametrical optimization is that complementary non-linear constraints such as weight and temperature can be added, making the model multi-physic. Then, several original position measurement techniques using existing sensors are developed including a low-cost custom single-photointerrupter sensor allowing for direction discrimination for fast-prototyping and a hybrid sensing method using tiny Hall sensors and taking advantage of the leaks of the main actuator magnet. Two innovative self-sensing methods are then presented, allowing for the measurement of the mover position of linear short-stroke actuators. The first solution estimates the position of the coil by measuring the acceleration through the back emf. However in this case, a constant acceleration is required, which strongly restrains the application scope. The second solution allows for a real-time measurement of the position thanks to a passive oscillating RLC circuit influenced by the variation of the coil impedance. All the solutions presented are low-cost, compact and require few computation resources. Finally, in order to illustrate the methodology proposed along the thesis, several prototypes are fabricated, giving an overview of the possibilities offered by multi-finger haptic devices. A haptic numeric pad is notably used in an experiment made in collaboration with the University Service of Child and Adolescent Psychiatry in Lausanne with the aim of improving the impaired emotional processing of psychotic adolescents. Moreover, the successful identification of several touch sensations on the same haptic pad lays the first stones of a new tactile language

Displaying shape haptically using MRF-based device

Smart materials such as magnetorheological fluids (MRF) offer an interesting medium to present viscoelastic cues in haptic displays as changes in the magnetic field are rapid, reversible and controllable. These interfaces have been evaluated in a number of medical and surgical simulators where they can provide cues regarding the viscoelastic properties of tissues. The present experiment determined whether eight different shapes could be identified reliably with a MRF haptic display and compared the information transfer (IT) associated with this type of display with that achieved by other forms of haptic communication. The overall performance of participants at identifying the shapes was good with a mean score of 70% correct and an IT of 2.13 bits. This type of display shows promise as a training tool for simulating tissue properties

Human factors issues in telerobotic decommissioning of legacy nuclear facilities

This thesis investigates the problems of enabling human workers to control remote robots, to achieve decommissioning of contaminated nuclear facilities, which are hazardous for human workers to enter. The mainstream robotics literature predominantly reports novel mechanisms and novel control algorithms. In contrast, this thesis proposes experimental methodologies for objectively evaluating the performance of both a robot and its remote human operator, when challenged with carrying out industrially relevant remote manipulation tasks. Initial experiments use a variety of metrics to evaluate the performance of human test-subjects. Results show that: conventional telemanipulation is extremely slow and difficult; metrics for usability of such technology can be conflicting and hard to interpret; aptitude for telemanipulation varies significantly between individuals; however such aptitude may be rendered predictable by using simple spatial awareness tests. Additional experiments suggest that autonomous robotics methods (e.g. vision-guided grasping) can significantly assist the operator. A novel approach to telemanipulation is proposed, in which an ``orbital camera`` enables the human operator to select arbitrary views of the scene, with the robot's motions transformed into the orbital view coordinate frame. This approach is useful for overcoming the severe depth perception problems of conventional fixed camera views. Finally, a novel computer vision algorithm is proposed for target tracking. Such an algorithm could be used to enable an unmanned aerial vehicle (UAV) to fixate on part of the workspace, e.g. a manipulated object, to provide the proposed orbital camera view

Proceedings of the 2nd European conference on disability, virtual reality and associated technologies (ECDVRAT 1998)

The proceedings of the conferenc