Browsing by Author "O'Malley, Marcia"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Affective Haptic Vest for Facilitating Interpersonal Communication
    (2021-12-21) Baldwin, Jacar; O'Malley, Marcia
    Touch plays an important role in deepening human connection. The emerging field of Affective Haptics seeks to analyze and design systems capable of processing human emotions through touch. There is an increasing focus on using the sense of touch to assist in communicating information: in entertainment, treatment procedures in social and developmental therapy, and social interaction. This thesis reports on the design of an Affective Haptic Vest, the design of vibrotactile cues displayed onto the back of the wearer of the vest, and an exploratory experiment to evaluate the ability of the vest and cues to facilitate communication of emotion. In particular, the goal of this experiment was to investigate if the vibrotactile cues displayed through the vest were capable of communicating four foundational human emotions: happiness, sadness, anger, and fear. The results were supportive of the hypothesis that the vest and cues were capable of conveying affect, and encourage us to explore the design of vibrotactile cues on the back as an affect area, and highlight areas to further consider when designing affective wearable devices.
  • Thumbnail Image
    Item
    Collective Transport of an Unknown Object by Multi Robots with Limited Sensing
    (2015-04-29) Habibi, Golnaz; McLurkin, James; Kavraki, Lydia; O'Malley, Marcia; Schwager, Mac
    This thesis presents a fully distributed approach to retrieve a large object from an unknown environment. The object is assumed to be located in an environment without GPS or Internet infrastructure. The object is too heavy to transport by one robot. The collective transport problem is broken into five major steps: 1) Exploring the unknown environment and finding the object. 2) Grasping the object. 3) Characterizing the object. 4) Planning a path to the desired location. 5) Transporting the object to the desired location. This thesis presents efficient distributed algorithms for robots with limited sensing to accomplish steps three to five. Object characterization includes centroid estimation and object dimension estimation. Two algorithms are developed for centroid estimation. In the first algorithm, each robot uses a communication tree to compute the sum of its children's positions. The second algorithm is based on pipelined consensus, which is an extension of pairwise gossip-based consensus. Two algorithms are presented to estimate object's dimensions. The first one is a distributed principal component analysis algorithm, and the second one is the distributed version of rotating calipers algorithm. A distributed path planning algorithm is presented. Robots have already been scattered across the terrain and collectively sample the obstacles in the environment. Robots use this sampling along with the estimated dimensions of the object, from above, to construct a configuration space of robots and the object. A variant of the distributed Bellman-Ford algorithm is then used to construct a shortest-path tree. A path navigation algorithm is presented to map each path segments to a distributed motion controller that can command the robots to transport the object. Four distributed motion controllers are designed including: rotation around a pivot robot, rotation in-place around an estimated centroid of the object, translation, and a combined motion of rotation and translation. Finally, a distributed recovery algorithm is presented to recover the robots efficiently and safely after collective transport. This recovery method uses k-redundant maximum-leaf spanning trees that guarantee connectivity during the recovery. All algorithms are verified through simulation as well as hardware experiments. The results are promising, and the algorithms successfully transport convex or concave objects in simulation and hardware experiments. After robots transport the object, robots are successfully recovered at home location by using the recovery algorithm. All algorithms discussed in this thesis are fully distributed, efficient, and robust to object shape and network population changes.
  • Thumbnail Image
    Item
    Exploration of Emotional Evocation Through Wearable Haptic Interfaces
    (2022-09-20) Sullivan, Daziyah; O'Malley, Marcia
    Nearly one in five adults in the United States suffer from mental illness. Emotion regulation techniques are commonly used to assist individuals with mood and anxiety disorders, two of the common types of mental illness. Wearable devices that deliver discreet haptic cues may be useful tools to assist with managing mental illness by allowing an individual to receive biofeedback regarding their mental state. This thesis reports on the design of affective haptic cues, based on music components, that are intended to elicit predictable emotional responses when displayed to the user in a wearable haptic bracelet. The music components of mode, loudness, and tempo were mapped to vibrotactile equivalents using the software tool Syntacts. Two experiments were conducted to evaluate user perception of and the affective response that the cues generated in users. Experiment 1 quantified the distinguishability of these music-based haptic cues. We investigated whether cues based on major and minor chords were distinguishable from one another. The results did not support the hypothesis that major and minor chord based haptic cues would be reliably identifiable. In Experiment 2, we investigated whether the duration and amplitude of a haptic cue affected the emotional response of the participant. The results were supportive of the hypothesis that the duration and amplitude affect the arousal rating of a cue, but there was no effect on valence ratings. The experimental results identify both the challenges and opportunities in using affective haptic cues displayed to users in a wearable device as a tool for emotion regulation.
  • Thumbnail Image
    Item
    Magnetic Flux Leakage Sensing: Modeling & Experiments
    (2015-07-20) Trevino Garcia, David A; Ghorbel, Fathi Hassan; Dick, Andrew J; Clark, John W; O'Malley, Marcia; Dutta, Sushant
    Nondestructive evaluation (NDE) is the inspection of samples for physical defects without altering the sample in question in any aspect. Magnetic Flux Leakage (MFL) has become one of the most widely used NDE techniques in robotic inspection of energy pipelines to prevent catastrophic failures. The MFL technique uses a magnetic field to magnetize ferromagnetic materials and correlates anomalies in the uniform field level to defects in the structure. Defect detection using the MFL technique is a mature area of work. However, defect characterization is an open research problem that can be decomposed into the Forward and Inverse Problems. The first problem deals with the characterization of the MFL signal for known defect shapes and dimensions, while the second one deals with the characterization of the defect shape from a known MFL signal. Several aspects of the MFL technique are not well understood yet, like the interplay of the MFL field for 3-dimensional defects. Another aspect that is not clear yet is the spatial properties of the MFL field components produced by complex 3-dimensional defect shapes. This dissertation addresses three issues identified with the MFL Forward Problem. An analytical 3-dimensional MFL model based on the Magnetic Dipole Model (MDM) and derived from Maxwell’s equations is presented. Under specific conditions, the magnetic field generated by a surface-breaking defect can be mathematically described as if it is caused by magnetic charges on the surface of the defect; such phenomenon can be described through Maxwell’s equations. The improved MDM characterizes the magnetic charges on the surface of the defect by using two parameters instead of one. Consequently, the MFL Forward Problem of complex defect shapes can be solved through the application of the improved model. Likewise, this thesis also studies the nature of the MFL signals in order to have a deep understanding of the Forward Problem. Therefore, a study of the correlation between the MFL signals (axial, radial, and tangential) through the improved MDM is addressed. The analysis exhibits the existence of a correlation between the three components of the MFL signal under some conditions. These results open more avenues in the field to better understand the physics of the MFL phenomenon. Hence, a methodology for the approximation of the behaviors of two MFL signal components from one extracted component is addressed. Additionally, another important approach to the MFL Forward Problem is conducted through experimentation. This dissertation explores a revolutionary 2-D type of sensing technology for application to MFL inspection known as Magneto Optical (MO) film. The feasibility of using the MO sensing in the MFL technique is presented through the development of an analytical model. Experimental and simulation validations are presented for the three approaches related to the MFL Forward Problem. Finally, this dissertation discusses the impact that these different contributions make toward solving the Inverse Problem.
  • Thumbnail Image
    ItemEmbargo
    Materials and Electromechanical Engineering of a Haptic System
    (2022-04-22) Ojha, Ved; Ajayan, Pulickel; O'Malley, Marcia
    Haptic technologies are set to play a key role in the design of next generation human-computer interfaces. While haptic feedback is being leveraged in areas such as consumer electronics, there is much to be done to create haptic systems that add value to our daily life. With the coming AR/VR revolution, wearables that add a sense of touch will enable truly immersive experiences. Haptic feedback is already augmenting professional training simulators used by astronauts, surgeons, soldiers to optimize learning routines. In other applications, haptic interfaces have already been shown to enable the deaf to "hear" again and the blind to navigate through environments with greater accuracy. Haptic feedback, therefore, is poised to redefine communications technology as a whole. I have explored actuation technologies, actuators with advanced polymers for generating crisp haptic feedback, data processing techniques and software design for triggering complex haptic patterns using sound signals, and low cost electronic design methodologies for driving arrays of electromagnetic actuators. I have demonstrated the above by designing a portable haptic vest using 112 eccentric rotating mass actuators, a haptic sleeve with 8 linear resonant actuators, and demonstrated a PVDF-TrFE polymer based piezoelectric actuator as a flexible and biocompatible alternative to traditional actuation technologies. A drawback that plagues most haptic systems is high power consumption, especially when operating at peak loads. When constructing energy efficient portable haptic systems, one must use an energy storage device capable of delivering high power while maintaining a stable energy density. Current lithium-ion batteries used in consumer electronics are energy dense but have low rate capability. I have explored a system known as a hybrid supercapacitor using a novel \ch{rGO/Nb2O5} nanocomposite anode, capable of delivering high energy at high current rates. As an intermediate energy storage device between batteries and supercapacitors it is ideal for analyzing the limitations of current energy storage systems and designing future energy solutions.
  • Thumbnail Image
    Item
    Modeling Password Entry on Mobile Devices: Please Check Your Password and Try Again
    (2015-04-21) Gallagher, Melissa Ann; Byrne, Michael D; Kortum, Philip; O'Malley, Marcia; Lane, David M
    Despite being recognized as a fundamentally flawed system, password authentication is a widely deployed security feature on desktop and mobile systems. Inputting complex passwords on mobile devices can be an onerous task. The composition of the passwords creates a unique challenge for people to input as not all characters are displayed on the keyboard at the same time, forcing the user to switch between multiple screens. While previous studies of text input on mobile devices have focused on typing words and phrases, little work has been done examining the effects screen switching has on text input. Three experiments were conducted in which subjects typed strings similar to secure passwords. Subjects were considerably slower typing password-like strings than typing standard text. Uncertainty about the location of symbols was a key factor in this slowdown. One of the largest contributors to the number of errors made was the size of the keyboard keys. This source of error suggests technologies that may aid error prevention. The results from these studies informed an ACT-R model of the task. The timing data generated from the model fits the experimental results well. The strategy that the model employs depends on the type of character it is trying to input providing further evidence that finding and inputting symbols decreases speed. Validated models of password input on mobile devices can aid designers in usability testing new password policies. The results have implications for both usability and security of password input on mobile devices.
  • Thumbnail Image
    Item
    The Generalizability of Cognitive Modeling Parameters
    (2015-07-06) Howie, Nicole; Byrne, Michael; O'Malley, Marcia; Kortum, Philip
    Increased awareness of the importance of usability has stemmed from the realization that customer satisfaction and revenue generation are affected by usability. One method that can be used to evaluate usability is cognitive modeling, which can make quantitative predictions about human performance across different tasks and devices. However, it is unclear if cognitive models can accurately predict older adult performance. Trewin et al. (2012) proposed that parameters used in models for older adults may have to be specific to a task and/or device. The purpose of this research was to determine if task and/or device type must be accounted for in parameters used to model older adult performance in a cognitive architecture. Jastrzembski and Charness (2007) estimated architectural parameters for older adults and were able to successfully predict performance of tasks performed with a mobile phone. The current study investigated if these parameters generalize to different tasks and devices. In the experiment, older (70 years and above) and younger (18 - 39 years old) adults performed two tasks with two different devices. Overall, the results from the behavioral data showed that older adults performed more slowly than younger adults, however older adult’s performance varied across task. Performance differences between older and younger adults due to device were caused by strategy differences. Cognitive models of each task with one device were created using modeling parameters that represented older and younger adults. Then the behavioral data were compared to the models. The models were mainly slower than older and younger adults across each task. The results helped provide evidence that task and/or device type are important and should be incorporated into modeling parameters. However, strategy must be accounted for as well in order to accurately model older adult performance.