Thesis (M.S. in mechanical engineering)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 11, 2010). "Department of School of Engineering and Computer Science, Vancouver." Includes bibliographical references (p. 58-59).

Thesis (M.S. in mechanical engineering)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 4, 2010). "School of Engineering and Computer Science." Includes bibliographical references (p. 77-81).

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

This thesis falls into the field of tactile displays that are meant to produce realistic tactile sensations, which replicate tactile sensations arising naturally when humans interact with the real world. / To begin with we need to know the biomechanics of the glabrous skin in human subjects. To this end, small patches of fingerpad skin are tested in vivo for their biomechanical properties under tangential loading. The skin is quasi-statically stretched and sheared to obtain its effective Young's modulus. Moreover, isotonic and isometric testing conditions are implemented to identify the viscoelasticity model of the skin. The results show a great deal of variability across subjects and it is observed that the glabrous skin exhibits nonlinear stiffening in tangential traction. The skin is consistently more elastic across the ridges, compared to along the ridges, regardless of the location of the sample on the fingerpad. The skin behaves visco-elastically but relaxes about twice as fast as it creeps. Finally, it is found that under large deformation, there is consistently 80% of hysteretic loss for a wide range of loading conditions. / Based on the results obtained by controlled testing, a high performance distributed display is designed. The display has a compact, yet modular structure. Its 6x10 piezo bimorph actuator array has a spatial resolution of 1.8x1.2 millimeters and a wide temporal bandwidth. The actuator mounting method is improved from conventional cantilever to dual-pinned lever, giving the actuator the capability of optimally coupling with glabrous skin. By using previously measured biomechanical data of the skin, we tune the parameters of the actuators to be optimal in terms of real deflection when they couple with the skin. The blocked force of the individual actuators can be adjusted from 0.15 N to 0.22 N to accommodate different applications. It is self-contained in a 150 cm3 volume and may be interfaced to most computers, provided that two analog outputs and six digital IO lines are available. Both public demonstration and psychophysical experiments have validated its effectiveness in rendering virtual tactile features. / The availability of a display raises the question of what signals should be used to drive it in order to render specific sensations. Some progress is made in this direction by analyzing the contact mechanics of fundamental cases, such as isolated indentation and traveling undulation. With the intention of explaining a tactile illusion engendered by straining the fingertip skin tangentially in a progressive wave pattern, resulting in the perception of a moving undulating surface, we carry out a contact mechanics analysis to derive the strain tensor field induced by a sinusoidal surface sliding on a finger, as well as the field created by a tactile transducer array deforming the fingerpad skin by lateral traction. We find that the first field can be well approximated by the second. Our results imply that, first, tactile displays using lateral skin deformation can generate tactile sensations similar to those using normal skin deformation. Second, there is a synthesis approach to achieve this result given constraints on the design of tactile stimulators. Third, the mechanoreceptors embedded in the skin must respond to the deviatoric part of the strain tensor field and not to its volumetric part. Finally, many tactile stimuli might represent for the brain an inverse problem to be solved. / Using the results of these investigations, we have demonstrated the feasibility of producing high-fidelity virtual tactile sensations.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 59-61).

No description available.

Note:

The simulation of surgical procedures, in the case of hard tissues such as bone or teeth milling, using a haptic milling surgery simulator requires a haptic device which can provide high stiffness and transparency. To mimic a real milling process of hard tissue, such as for example creating a narrow channel or cavity, the simulator needs to provide force/torque feedback in 5–6 degrees of freedom (DOF). As described in this thesis, research has been performed to develop and optimize a haptic device that can provide high stiffness and force/torque capabilities to facilitate haptic interaction with stiff tissues.  The main contributions of this thesis are: (i) The use of a model-based design methodology for the design of haptic devices.  The proposed methodology is applied to a case study, i.e. the design and optimization of a haptic device based on parallel kinematics. Device requirements were elicited through dialogues with a prospective user from a neurosurgery clinic. In the conceptual design phase, different parallel concepts have been investigated and analyzed based on functional qualities such number of degrees of freedom, workspace size and force/torque capabilities. This analysis led to the selection of a specific 6 DOF kinematic structure for which dimension synthesis was performed including multi-objective optimization followed by control synthesis. Finally, a device prototype was realized and its performance verified. (ii) Optimization of the device for best kinematic and dynamic performance. For optimization, performance indices such as workspace-to-footprint ratio, kinematic isotropy and inertial indices were used. To cope with the problem of non-uniform units in the components of the Jacobian matrix, various normalization techniques were investigated. A new multi-objective optimization function is introduced to define the optimization problem, which is then resolved using multi-objective genetic algorithms. A sensitivity analysis of the performance indices against each design parameter is performed, as a basis for selecting a final set of design parameter values. (iii) A control strategy is investigated to achieve high transparency and stability of the device. The control strategy is based on careful analysis of the dynamics of the haptic device, computed torque feed-forward control and force control based on current feedback. (iv) Finally, experiments both separately in the lab and by using the device in a haptic milling surgery simulator were performed. Results from a face validity study performed in collaboration with orthopedists verify that the new haptic device enables high-performance force and torque feedback for stiff interactions. / QC 20120302

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.

Haptic simulation of medical procedures is an active area of research in engineering and medicine. Analogous to flight simulators for pilots, surgery simulators can allow medical students and doctors to practice procedures in a risk free and well monitored virtual environment. The quality of interaction that a surgery simulator can generate is dependent upon many components. In this thesis, careful attention is paid to the haptic display of viscous effects. / Viscous terms, defined here as terms that are dependent upon velocity, are typically computed 'using a discrete time backwards difference estimation of the velocity. It is well known that differentation has the tendency to amplify high frequency noise, and as a result, the backwards difference estimation generates considerable errors when applied to the quantized position readings from a digital encoder. Prior to this work, the only feasible method to improve velocity estimation was to use a variety of observation or filtering techniques, all of which inevitably add phase delay. In this thesis, the backwards difference operation was analyzed in detail. It was found that feedback viscosity simulation is very non-robust to noise, and oscillations exist in the presence of quantization noise regardless of the physical parameters of the plant. / A typical haptic interface for surgery simulation consists of a mechanical linkage driven by electric motors. These linkages are controlled with a computer using a discrete-time force update law that generates a prescribed force given the user's position in the medical virtual environment. It is clear from the literature that a haptic interface must have some level of physical dissipation to enable a passive rendering due to the inherent instability associated with time delayed systems. However, dissipation in typical haptic interfaces is a byproduct of their design, and is neither controllable nor easily identifiable. A prototype haptic interface is presented in this thesis that uses eddy current brakes to add high bandwidth programmable dissipation to an existing motor linkage. The new hardware has been optimized experimentally to maximize damping and minimize inertia given conventional machining and available material constraints. / A new paradigm in the control of haptic interfaces is time-domain passivity control. Passive systems are desirable in haptics because a passive system is globally stable, passivity theory applies to linear and nonlinear systems alike, and a user cannot extract energy from a passive system. Passivity controllers monitor the energy flow in the device and add virtual damping to remove any energy that violates the passivity constraint. Unfortunately, the amount of virtual damping available to a given device is limited by the physical dissipation that it exhibits. If the device is directly driven and light, such as the pantograph, the available virtual damping is insufficient to maintain the passivity constraint. The eddy current brakes allow programmable physical damping to be used in place of virtual damping which has been shown with experiments to improve the stable impedance range of a haptic interface. / It is clear from the literature that most tissues in a human body exhibit viscoelastic behavior. Simulation of viscoelastic objects requires that the velocity of interaction be known. Because typical haptic interfaces use digital encoders to sample position, the estimated velocity signal is noisy, delayed or both. Eddy current brakes are viscous actuators by nature, as they generate a resistive force proportional to the velocity. To take advantage of this fact, viscoelastic decomposition algorithms were developed that can output viscous components to the eddy current brakes and elastic components to the motors. This technique reduces or eliminates the use of a velocity estimation signal in the feedback loop which improves passivity, reduces motor saturation effects, and allows for a wider stable range of mechanical impedances than conventional haptic interfaces can achieve.