The study of haptics, or the sense of touch in virtual reality environments, is constantly looking for improvements in modeling with a high fidelity. Highly detailed models are desirable, but they often lead to slow processing times, which can mean a loss of fidelity in the force feedback sensations. Model compression techniques are critical to balancing model detail and processing time. One of the proposed compression techniques is to create multiple models of the same object but with different levels of detail (LOD) for each model. The technique hypothesizes that the human arm loses sensitivity to forces with the increase of its movement speed. This the compression technique determines which model to use based on the user's movement speed. This dissertation examines studies how the movement speed of the user affects the user's ability to sense changes in details of haptic models. Experiments are conducted using different haptic surfaces. Their levels of detail are changed while the subject interacts with them to mimic the effects of a multiresolution compression implementation. The tests focus on the subjects' ability to differentiate changes of the surfaces at each speed. The first experiment uses curved surfaces with multiple resolutions. This test observes the sensitivity of the user when the details on the surface are small. The results show that the subjects are more sensitive to changes of small details at a lower speed than higher speed. The second experiment measures sensitivity to larger features by using trapezoidal surfaces with different angles. The trapezoidal surfaces can be seen as a low-resolution haptic model with only two vertices, and changing the angles of the trapezoids is seen as changing the radii of curvature. With the same speed settings from the first experiment applied to the subjects, the sensitivity for changes in curvature is predicted to decrease with the increase of speed. However, the results of this experiment proved otherwise. The conclusions suggest that multiresolution designs are not a straightforward reduction of LOD, even though the movement speed does affect haptic sensitivity. The model's geometry should be taken into account when designing the parameters for haptic model compression. The results from the experiments provide insights to future haptic multiresolution compression designs.

On-the-go users' interaction with mobile devices often requires high visual attention that can overtax limited human resources. For example, while attending information displayed on a mobile device, on-the-go users who are driving a car or walking in the street can easily fail to see a dangerous situation. This dissertation explores the benefits of wearable tactile displays (WTDs) to support eyes-free interaction for on-the-go users. The design and implementation of the WTDs are motivated by two principles in mobile user interaction that have been proven both commercially and academically: wristwatch interfaces that reduce the time for device acquisition and tactile interfaces that eliminate the need for visual attention. In this dissertation, I present three phases of design iteration on WTDs to provide the design rationale and challenges. The result of the iterative design is evaluated through in-depth formal investigations with novice users in two experiments: user perception of the tactile stimuli and information throughput in association with multiple tactile parameters, and perception of the tactile stimuli and information throughput when the user is visually distracted. The first experiment explores general human capabilities in perceiving tactile stimuli on the wrist. It reveals that subjects could discriminate 24 tactile patterns with 98% accuracy after 40 minutes of training. Of the four parameters (intensity, starting point, rhythm, direction) that were configured to design the 24 patterns, intensity was the most difficult parameter to distinguish, and temporal variation was the easiest. The second experiment explores users' abilities to perceive incoming alerts from two mobile devices (WTD and mobile phone) with and without visual distraction. The second experiment reveals that when the user was distracted visually, reaction time to perceive the incoming alerts became slower with the mobile phone alert but not with the WTD.

The study of haptics, or the sense of touch in virtual reality environments, is constantly looking for improvements in modeling with a high fidelity. Highly detailed models are desirable, but they often lead to slow processing times, which can mean a loss of fidelity in the force feedback sensations. Model compression techniques are critical to balancing model detail and processing time. One of the proposed compression techniques is to create multiple models of the same object but with different levels of detail (LOD) for each model. The technique hypothesizes that the human arm loses sensitivity to forces with the increase of its movement speed. This the compression technique determines which model to use based on the user's movement speed. This dissertation examines studies how the movement speed of the user affects the user's ability to sense changes in details of haptic models. Experiments are conducted using different haptic surfaces. Their levels of detail are changed while the subject interacts with them to mimic the effects of a multiresolution compression implementation. The tests focus on the subjects' ability to differentiate changes of the surfaces at each speed. The first experiment uses curved surfaces with multiple resolutions. This test observes the sensitivity of the user when the details on the surface are small. The results show that the subjects are more sensitive to changes of small details at a lower speed than higher speed. The second experiment measures sensitivity to larger features by using trapezoidal surfaces with different angles. The trapezoidal surfaces can be seen as a low-resolution haptic model with only two vertices, and changing the angles of the trapezoids is seen as changing the radii of curvature. With the same speed settings from the first experiment applied to the subjects, the sensitivity for changes in curvature is predicted to decrease with the increase of speed. However, the results of this experiment proved otherwise. The conclusions suggest that multiresolution designs are not a straightforward reduction of LOD, even though the movement speed does affect haptic sensitivity. The model's geometry should be taken into account when designing the parameters for haptic model compression. The results from the experiments provide insights to future haptic multiresolution compression designs.

In cooperative networked haptic systems, some distributed distant users may decide to leave or join the cooperation while other users continue to manipulate the shared virtual object (SVO). Cooperative haptic systems that support interaction among a variable number of users, called scalable haptic cooperation systems herein, are the focus of this research. In this thesis, we develop distributed control strategies that provide stable and realistic force feedback to a varying number of users manipulating a SVO when connected across a computer network with imperfections (such as limited packet update rate, delay, jitter, and packet-loss). We fi rst propose the average position (AP) scheme to upper bound the effective stiff ness of the SVO coordination and thus, to enhance the stability of the distributed multi-user haptic cooperation. For constant and small communication delays and over power-domain communications, the effectiveness of the proposed AP paradigm is compared with the traditional proportional-derivative (PD) scheme via multi-rate stability and performance analyses supported with experimental verif cations. Next, in a passivity-based approach, the scalability is pursued by implementing the AP scheme over wave-domain communication channels along with passive simulation of the dynamics. By constructing a passive distributed SVO in closed-loop with passive human users and haptic devices, we guarantee the stability of the distributed haptic cooperation system. However, energy leak at joining/leaving instances may compromise the passivity of the SVO. We examine the preservation of passivity of the proposed SVO scheme for such situations. A switching algorithm is then introduced in order to improve the performance of the cooperative haptic system. Experiments in which three users take turn in leaving or joining the cooperation over a network with varying delay and packet-loss will support the theoretical results. / Graduate / 0771 / 0548 / 0537 / 0544 / rrakhsha@uvic.ca

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Published Article / This paper outlines a haptic "construction" system as means of navigating an interactive design approach to sculpture. A user system applicable to haptic generated form is sought after by way of exploring 'construction' as 3-D modality comprised of an interrelated synthesized system. The paper schematically outlines technological and sensory user 'construction' modalities as elements towards an expanded 'synthesis', 'construction' and 'production' systemic structure as a way forward for haptic sculpting. 'Construction' modalities applied to the case study explore human and machine haptics where the PHANTOM® haptic device and FreeForm® Modeling™ CAD software developed by SensAble Technologies® are used to generate, manipulate and render the touch and feel of a virtual designed sculpture.

This thesis aims at real-time measurements of human trust, satisfaction, and frustration in human-robot teaming. Recent studies suggest that humans are inclined to have a negative attitude towards using autonomous systems. These ndings elevate the necessity of conducting research to better understand the key factors that a ect the levels of trust, satisfaction and frustration in Human-Robot Interaction (HRI). We utilized a new sequential and collaborative approach for HRI data collection that employed trust, satisfaction and frustration as primarily evaluative metrics. We also used haptic feedback through a soft actuator armband to help our human subjects control a robotic hand for grabbing or not grabbing an object during our interaction scenarios. Three experimental studies were conducted during our research of which the rst was related to the evaluation of aforementioned metrics through a collabora- tive approach between the Baxter robot and human subjects. The second experiment embodied the evaluation of a newly fabricated 3D- nger for the I-Limb robotic hand through a nuclear-waste glove. The third experiment was based on the two previous studies that focused on real-time measurements of trust, satisfaction and frustration in human-robot teaming with the addition of pressure feedback to the system through soft actuators. In the last case, human subjects had more controls over our robotic systems compared to earlier experiments leading to a more collaborative interaction and teaming. The results of these experiments illustrated that human subjects can rebuild their trust and also increase their satisfaction levels while lowering their frus- tration levels after failures or any faulty behavior. Furthermore, our analyses showed that our methods are highly e ective for collecting honest and genuine data from hu- man subjects and lays the foundation for more-involved future research in the domain of human-robot teaming. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Digital Clay is a tactile array of linear fluidic actuators which provide distributed sensing and position control through the use of an embedded position sensor. The actuator implementation is achieved by two-way hydraulically-driven pistons which are integrated with computer controlled valves. Each actuator is connected to an underlying base plate which is in fluidic communication with high and low pressure reservoirs. The research focuses on the aspects of the fluidics necessary to operate the actuators and control actuation of Digital Clay. The main objectives of this work are the characterization of the fluid flow through the system and the design and implementation of an embedded inductance-based position sensor. Each actuator in Digital Clay is individually addressable and is controlled through the use of a closed-loop proportional integral controller with position feedback from the embedded inductance-based sensor. Also presented in this work is the characterization of an individual fluidic actuator and the realization of a 5x5 tactile array of actuators.

Hand rehabilitation after injury or illness may allow a patient to regain full or at least partial use of a limb. However, rehabilitation often requires the patient to perform multiple repetitions of motions. While absolutely essential to regaining usage, such exercises are not always mentally engaging or enjoyable for the patient. The loss or degradation of the use of the hands can cause considerable loss of independence. In this dissertation, we present Mobile Music Touch (MMT), a wireless glove paired with a computing device, such as a laptop, smart phone, or MP3 player. The MMT system plays a song, while also "tapping" the fingers using vibration motors to indicate the correct finger to use to play the song on a piano keyboard. Learning a new skill or activity without active focus, an idea called Passive Haptic Learning(PHL) may allow an individual to learn one skill through their sense of touch while performing another, unrelated activity. Most rehabilitation activities are active in nature, requiring the focused participation of the injured person. Passive rehabilitation is the idea that some technologies and activities may bring about beneficial changes without the active engagement of the injured person. In order to study the concepts of PHL and PHR, we propose the Mobile Music Touch (MMT) system. We show that using passive rehabilitation in conjunction with the active rehabilitation of piano playing will bring about a greater degree of improvement in the hands than that achieved using only active rehabilitation. This dissertation research makes three unique contributions. First, we demonstrate that Passive Haptic Learning (PHL) using just the sense of touch is feasible and provides a form of learning and reinforcement of learned skills and tasks. Second, we identify the attributes and design features of a glove suited for long term wear by persons who use a manual wheelchair for mobility. Third, we show that Passive Haptic Rehabilitation (PHR) is possible using vibrotactile stimulation of the hands in persons classified as tetraplegic due to incomplete spinal cord injury.

Missing from much of civic/public spaces today is the potential choreography between body, imagination, and the built environment. This is often a result of a diminished sensation between ourselves and the coupling of constructed and natural spaces. It is precisely this miscommunication which led to an exploration of the haptic sense and a material investigation of the choreography between our bodies, our buildings, and our landscape. In order to create a memorable space or in the case of this exercise, create place from path, a conservation of the spirit of the players/pieces is necessary. The experience of being in a place occurs in time, is much more than visual, and is as complex as our bodies and as immense as our imaginations. The movement of our bodies traversing a built environment gives value to the spaces we inhabit. Through the investigation of a little league baseball park along the Potomac River in Alexandria, Virgina, a series of haptic patterns with distinct pauses and progressions in which the body and mind responds to the situation presented is created. / Master of Architecture