京都大学 / 新制・課程博士 / 博士(工学) / 甲第23884号 / 工博第4971号 / 新制||工||1776(附属図書館) / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 小森 雅晴, 教授 松野 文俊, 教授 藤本 健治 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The design of the landing gear is one of the more fundamental aspects of aircraft design. The design and integration process encompasses numerous engineering disciplines, e.g., structure, weights, runway design, and economics, and has become extremely sophisticated in the last few decades. Although the design process is well-documented, no attempt has been made until now in the development of a design methodology that can be used within an automated environment. As a result, the process remains to be a key responsibility for the configuration designer and is largely experience-based and graphically-oriented. However, as industry and government try to incorporate multidisciplinary design optimization (MDO) methods in the conceptual design phase, the need for a more systematic procedure has become apparent. The development of an MDO-capable design methodology as described in this work is focused on providing conceptual designer with tools to help automate the disciplinary analyses, i.e., geometry, kinematics, flotation, and weight. Documented design procedures and analyses were examined to determine their applicability, and to ensure compliance with current practices and regulations. Using the latest information as obtained from industry during initial industry survey, the analyses were in terms modified and expanded to accommodate the design criteria associated with the advanced large subsonic transports. Algorithms were then developed based on the updated analysis procedures to be incorporated into existing MDO codes. / Master of Science

The current study examined the effects of bite blocks on articulatory kinematics when producing diphthongs /ɑɪ/ and /ɑʊ/ within a phrase. Participants consisted of 20 young adults (10 males, 10 females) with no speech, language or hearing disorders. Participants produced the diphthongs in the carrier phrase Im an owl that hoots. A Northern Digital Instruments Wave electromagnetic articulograph measured the articulatory movements while the speaker produced the stimuli in two conditions (pre bite block insertion and post bite block insertion). Bilateral bite blocks were made using Express dental putty, which is a silicone impression material, in order to create a 10 mm inter-incisal gap. Marker distance, maximum speed, and jaw contribution to tongue movement for three sensors (tongue back, tongue mid, tongue front) were calculated for the diphthongs segmented from the carrier phrase. F1 and F2 transitions and rate were also calculated for each diphthong. Results revealed kinematic differences during diphthong production after the bite block was inserted. Tongue movements independent from the jaw increased after the bite block was inserted, especially during production of the diphthong /ɑʊ/. Bite block by gender interactions during production of the diphthong /ɑɪ/ revealed larger and faster initial movements for males. The results did not reveal any significant acoustic changes other than a longer transition duration. Kinematic adjustments were sufficient to maintain overall similar acoustic output before and after bite block insertion.

The current study examined the lingual kinematic and acoustic effects of bite blocks on vowels in a sentence context. Twenty adult native English speakers (10 male, 10 female) with no speech, language, or hearing deficits participated in the study. The corner vowels found in the sentence, The blue spot is on the black key again (i.e., /u/, /ɑ/, /æ/, /i/), were measured kinematically and acoustically immediately before and after bite block insertion. The participants' speech was audio-recorded and their lingual articulatory movements were measured with a Northern Digital Instruments Wave electromagnetic articulograph. The sensor coils were attached to three different parts on the tongue (back, middle, and front). Acoustic analysis of the vowel formants revealed that the vowel articulation index and vowel space area decreased significantly following bite block insertion. Kinematic analysis of the sensors on the tongue revealed that the kinematic vowel articulation index decreased significantly for the back and middle of the tongue but not for the front. Thus, adjustments to the position of the front of the tongue were sufficient to compensate for the bite block perturbation, while the same measures for the back and middle of the tongue were significantly affected. This was likely due to the relative independence in the movement of the front of the tongue, given its distance from the posterior point of attachment between the tongue and mandible. These findings suggest that the effects of articulatory perturbation can be more fully understood when kinematic and acoustic measures are considered together.

This dissertation presents a comprehensive exploration encompassing the design, development, control and the application of reinforcement learning-based force planning for the autonomous grasping capabilities of the innovative assistive robotic exoskeleton gloves. Exoskeleton devices have emerged as a promising avenue for providing assistance to individuals with hand disabilities, especially those who may not achieve full recovery through surgical interventions. Nevertheless, prevailing exoskeleton glove systems encounter a multitude of challenges spanning design, control, and human-machine interaction. These challenges have given rise to limitations, such as unwieldy bulkiness, an absence of precise force control algorithms, limited portability, and an imbalance between lightweight construction and the essential functionalities required for everyday activities. To address these challenges, this research undertakes a comprehensive exploration of various dimensions within the exoskeleton glove system domain. This includes the intricate design of the finger linkage mechanism, meticulous kinematic analysis, strategic kinematic synthesis, nuanced dynamic modeling, thorough simulation, and adaptive control. The development of two distinct types of series elastic actuators, coupled with the creation of two diverse exoskeleton glove designs based on differing mechanisms, constitutes a pivotal aspect of this study. For the exoskeleton glove integrated with series elastic actuators, a sophisticated dynamic model is meticulously crafted. This endeavor involves the formulation of a mathematical framework to address backlash and the subsequent mitigation of friction forces. The pursuit of accurate force control culminates in the proposition of a data-driven model-free force predictive control policy, compared with a dynamic model-based force control methodology. Notably, the efficacy of the system is validated through meticulous clinical experiments. Meanwhile, the low-profile exoskeleton glove design with a novel mechanism engages in a further reduction of size and weight. This is achieved through the integration of a rigid coupling hybrid mechanism, yielding pronounced advancements in wearability and comfortability. A deep reinforcement learning approach is adopted for the real-time force planning control policies. A simulation environment is built to train the reinforcement learning agent. In summary, this research endeavors to surmount the constraints imposed by existing exoskeleton glove systems. By virtue of advancing mechanism design, innovating control strategies, enriching perception capabilities, and enhancing wearability, the ultimate goal is to augment the functionality and efficacy of these devices within the realm of assistive applications. / Doctor of Philosophy / This dissertation presents a comprehensive exploration encompassing the design, development, control and the application of reinforcement learning-based force planning for the autonomous grasping capabilities of the innovative assistive robotic exoskeleton gloves. Exoskeleton devices hold significant promise as valuable aids for patients with hand disabilities who may not achieve full recuperation through surgical interventions. However, the present iteration of exoskeleton glove systems encounters notable limitations in terms of design, control mechanisms, and human-machine interaction. Specifically, prevailing systems often suffer from bulkiness, lack of portability, and an inadequate equilibrium between lightweight construction and the essential functionalities imperative for daily tasks. To address these challenges, this research undertakes a comprehensive exploration of diverse facets within the exoskeleton glove system domain. This encompasses a detailed focus on mechanical design, control strategies, and human-machine interaction. To address wearability and comfort, two distinct exoskeleton glove variations are devised, each rooted in different mechanisms. An innovative data-driven model-free force predictive control policy is posited to enable accurate force regulation. Rigorous clinical experiments are conducted to meticulously validate the efficacy of the system. Furthermore, a novel mechanism is seamlessly integrated into the design of a new low-profile exoskeleton glove, thereby augmenting wearability and comfort by minimizing size and weight. A deep reinforcement learning based control agent, which is trained within a simulation environment, is devised to facilitate real-time autonomous force planning. In summary, the overarching objective of this research lies in rectifying the limitations inherent in existing exoskeleton glove systems. By spearheading advancements in mechanical design, control methodologies, perception capabilities, and wearability, the ultimate aim is to substantially enhance the functionality and overall efficacy of these devices within the sphere of assistive applications.

Military-related blast-exposure and sports-related closed-head impact-injury are associated with traumatic brain injury (TBI) and chronic traumatic encephalopathy (CTE), a tau protein neurodegenerative disease. Despite growing awareness of links between TBI and CTE, the mechanisms underpinning this association, and relationship to concussive and subconcussive head injury, are poorly understood. This dissertation addresses the hypothesis that blast-exposure and impact-injury induce traumatic acceleration of the head and injurious forces in the brain that led to structural brain damage (TBI) and chronic sequelae, including CTE. This hypothesis was addressed in five specific aims: 1) develop a blast shock tube instrument and impact instrument to deliver relevant blast-exposure and impact-injury to mice, 2) validate a mouse model of single blast-exposure that recapitulates brain pathology in blast-exposed military veterans diagnosed with CTE, 3) validate a mouse model of single-repeat closed-head impact-injury that recapitulates brain pathology in contact sport athletes diagnosed with CTE, 4) match kinematics of blast and impact models using high-speed videography, 5) deploy kinematically-matched mouse models of single blast-exposure and single-repeat closed-head impact-injury to investigate mechanisms that trigger experimental concussion and post-traumatic sequelae. Blast and impact injuries were shown to cause similar CTE-linked brain pathologies, including microvasculopathy, neuroinflammation, astrogliosis, and phosphorylated tauopathy. Despite similarities in chronic consequences, blast-exposure and impact-injury produced different acute neurological responses. Surprisingly, impact-injured mice demonstrated signs of experimental concussion, whereas blast-exposed mice with comparable head kinematics did not. Computational modeling indicated that point loading of forces during impact, as opposed to distributed loading in blast, caused ipsilateral spikes in cortical shear stress which we conclude to be responsible for experimental concussion. The blast-exposure and impact-injury models have been and will continue to be invaluable tools for elucidating the mechanisms of and relationships between concussion, TBI, and CTE. / 2019-07-09T00:00:00Z

The aim of this thesis was to determine the biomechanical adaptations made by active unilateral trans-tibial amputees when they used a prosthesis incorporating a hydraulically-damped, articulating ankle-foot device compared to non-hydraulically attached devices. Kinematic and kinetic data were recorded while participants ambulated over a flat and level surface at their customary walking speeds and at speeds they perceived to be faster and slower using the hydraulic device and their habitual foot. Use of the hydraulic device resulted in increases in self-selected walking speeds with a simultaneous reduction in intact-limb work per meter travelled. Use of the device also attenuated inappropriate fluctuations in the centre-of-pressure trajectory beneath the prosthetic foot and facilitated increased residual-knee loading-response flexion and prosthetic-limb load bearing during stance. These changes occurred despite the hydraulic device absorbing more, and returning less, energy than the participants’ habitual ankle-foot devices. The changes were present across all walking speeds but were greatest at customary walking speeds. The findings suggest that a hydraulic ankle-foot device has mechanical benefits, during overground gait, for active unilateral trans-tibial amputees compared to other attachment methods. The findings also highlight that prosthetic ankle-foot device ‘performance’ can be evaluated using surrogate measures and without modelling an ‘ankle joint’ on the prosthetic limb.

Background and Objectives: The foot comprises of active contractile and passive connective tissue components, which help maintain stability and facilitate movement during gait. The role of age- or pathology-related degeneration and the presence of fat within muscles in foot function and pain remains unclear. The existence of fat has to date not been quantified or compared between individuals according to age, sex, side or subregion. Materials and Methods: 18 cadaveric feet (mean age 79 years) were sectioned sagittally and photographed bilaterally. Fat in the plantar muscular space of the foot (PMSF) was quantified through the previously validated manual fat quantification method, which involved observing photographs of each section and identifying regions using OsiriX. Fat volume and percentage was calculated using a modified Cavalieri’s method. Results: All feet had fat located within the PMSF, averaging 25.8% (range, 16.5–39.4%) of the total PMSF volume. The presence of fat was further confirmed with plastination and confocal microscopy. Conclusions: These findings suggest that fat within the PMSF is a consistent but highly variable finding in elderly cohorts. Fat within the foot muscles may need to be considered a norm when comparing healthy and non-healthy subjects, and for therapeutic interventions to the foot. Further work is required to understand in detail the morphological and mechanical presence of fat in the foot, and compare these findings with pathological cohorts, such as sarcopenia. Additionally, future work should investigate if fat may compensate for the degeneration of the intrinsic muscles of the foot, with implications for both the use of orthotics and pain management.

The belief that intentions are hidden away in the minds of individuals has been circulating for many years. Theories of indirect perception, such as the Theory of Mind, have since been developed to help explain this phenomenon. Conversely, research in the field of human kinematics and event perception have also given rise to theories of direct perception. The purpose of the study was to determine if intentionality can be directly perceived rather than requiring inferential processes. Prior research regarding kinematics of cooperative and competitive movements have pointed toward direct perception, demonstrating participants can accurately judge a movement as cooperative or competitive by simply observing point-light displays of the isolated arm movements. Considering competitive movements are often performed faster than cooperative movements, speed was perturbed for the purpose of this study to determine if participants are relying on cues or if they can indeed perceive a unique kinematic pattern that corresponds to intentionality. Judging the clips correctly despite perturbation would suggest perception is direct. Additionally, we hypothesized judgments accuracy would be higher in the presence of two actors pointing to the use of interpersonal affordances. Twenty-eight participants from the University of Central Florida were asked to judge 40 clips presented in random order including: normal or perturbed competitive actions with one or two actors; normal or perturbed cooperative actions with one or two actors. Percent correct and reaction time data were analyzed on SPSS using a repeated measures ANOVA. Results rejected the hypothesis that social perception is direct and supported indirect perception, indicating participants relied on cues to make judgments, and provided potential support for the interpersonal affordance hypothesis.

Research has shown that in Human-Human Interactions kinematic information reveals that competitive and cooperative intentions are perceivable and suggests the existence of a cooperation bias. The present study invokes the same question in a Human-Robot Interaction by investigating the relationship between the acceleration of a virtual robot within a virtual reality environment and the participants perception of the situation being cooperative or competitive by attempting to identify the social cues used for those perceptions. Five trials, which are mirrored, faster acceleration, slower acceleration, varied acceleration with a loss, and varied acceleration with a win, were experienced by the participant; randomized within two groups of five totaling in ten events. Results suggest that when the virtual robot's acceleration pattern were faster than the participant's acceleration the situation was perceived as more competitive. Additionally, results suggest that while the slower acceleration was perceived as more cooperative, the condition was not significantly different from mirrored acceleration. These results may indicate that there may be some kinematic information found in the faster accelerations that invoke stronger competitive perceptions whereas slower accelerations and mirrored acceleration may blend together during perception; furthermore, the models used in the slower acceleration conditions and the mirrored acceleration provide no single identifiable contributor towards perceived cooperativeness possibly due to a similar cooperative bias. These findings are used as a baseline for understanding movements that can be utilized in the design of better social robotic movements. These movements would improve the interactions between humans and these robots, ultimately improving the robot's ability to help during situations.