Simulated Robotic Autonomous Agents with Motion Evolution

This research implemented autonomous control of robotic agents. The movement controls are simulated within a virtual environment. The control system algorithms were subjected to evolution. Genetic algorithms were implemented to enable the robotic agents to adapt in response to objects within the virtual environment. Additionally, each robot’s physical characteristics were subjected to evolution through a survival of the fittest system based on crossover with random mutations. Survival of the fittest was simulated by a shortage of food causing competition. When the food quantity was increased the evolution rate decreased. With increased food, there was reduced competition and average fitness stopped increasing over time. Removing the food bottleneck stopped the survival of the fittest mechanism

SMA-Based Muscle-Like Actuation in Biologically Inspired Robots: A State of the Art Review

New actuation technology in functional or "smart" materials has opened new horizons in robotics actuation systems. Materials such as piezo-electric fiber composites, electro-active polymers and shape memory alloys (SMA) are being investigated as promising alternatives to standard servomotor technology [52]. This paper focuses on the use of SMAs for building muscle-like actuators. SMAs are extremely cheap, easily available commercially and have the advantage of working at low voltages. The use of SMA provides a very interesting alternative to the mechanisms used by conventional actuators. SMAs allow to drastically reduce the size, weight and complexity of robotic systems. In fact, their large force-weight ratio, large life cycles, negligible volume, sensing capability and noise-free operation make possible the use of this technology for building a new class of actuation devices. Nonetheless, high power consumption and low bandwidth limit this technology for certain kind of applications. This presents a challenge that must be addressed from both materials and control perspectives in order to overcome these drawbacks. Here, the latter is tackled. It has been demonstrated that suitable control strategies and proper mechanical arrangements can dramatically improve on SMA performance, mostly in terms of actuation speed and limit cycles

Analysis and control of a dragonfly-inspired robot

Dragonflies demonstrate unique and superior flight performances than most of the other insect species and birds. They are equipped with two pairs of independently controlled wings granting an unmatchable flying performance and robustness. In this paper it is studied the dynamics of a dragonfly-inspired robot. The system performance is analyzed in terms of time response and robustness. The development of computational simulation based on the dynamics of the robotic dragonfly allows the test of different control algorithms. We study different movement, the dynamics and the level of dexterity in wing motion of the dragonfly. The results are positive for the construction of flying platforms that effectively mimic the kinematics and dynamics of dragonflies and potentially exhibit superior flight performance than existing flying platforms.N/

Physiological Aeroecology: Anatomical and Physiological Adaptations for Flight

Flight has evolved independently in birds, bats, and insects and was present in the Mesozoic pterosaurians that have disappeared. Of the roughly one million living animal species, more than three-quarters are flying insects. Flying is an extremely successful way of locomotion. At first glance, this seems surprising because leaving the ground and moving in the air is energetically expensive. We will therefore start with the question: why do some animals spend a substantial proportion of their life in the air? To generate lift, a few key features are required, and yet, animals show incredible diversity in their flight mechanics. We will review constraints imposed by body size including anatomical adaptations of the skeleton, muscles, and organs necessary to stay airborne with a special focus on the wings. Ecology of the aerial organism, such as diet or migration, has diversified flight styles and the physiological adaptations required to optimize performance. For example, animals are exposed to low temperatures and low oxygen pressure at high altitude, whereas overheating can pose a problem at low altitudes. Moreover, aerial prey can be particularly apparent to aerial predators resulting in selection on flight speed and maneuverability of predators and prey. Flight is energetically costly, much more costly than walking, with the majority of the cost dictated by body mass. Hence, adding weight load to fuel flight also adds to the cost of flight. We review energy supply for flight, and special adaptations for long-term flights. Aeroecology has resulted in extraordinary visual and aural sensory systems of predators, which in coordination with the locomotor system are under strong selection to detect and intercept prey in flight

The hermeneutics of scribal rewriting in Targum Jonathan Ezek 1

This paper examines a number of expansions and rewordings in Tg. J. Ezek 1 that alter or elaborate upon the description of the celestial creatures. The object is threefold: to identify textual cues within the Targum’s Vorlage that sparked expansions or rewordings, to explain the exegetical choices reflected in those expansions and rewordings, and to deduce something about the hermeneutical assumptions under which those choices were made. Along the way, I explain several features of the Targum in new ways, but the principal objects of my inquiry are the scribes responsible for Targum Jonathan and the various ways that they interacted with their Hebrew Vorlage. I propose that the expansions and rewordings never reflect exuberance or whimsy on the part of the targumic scribes. Rather, they represent a disciplined effort to produce an accurate reading of their Hebrew text, undertaken according to certain hermeneutical assumptions, assumptions that are co-extensive with their assumptions about the nature of their source texts as scripture.Publisher PDFPeer reviewe

Rite of Identity

Rite of Identity, a graduate thesis film, is a 2D animated visual poem of deaf children’s experiences. The film follows the protagonist’s journey in navigating a visual realm and a black-and-white realm, which represent the deaf world and the hearing world. Childhood experiences of struggling to assimilate into mainstream society are conveyed through the protagonist in the black-and-white realm. The purpose of the film is to encourage the viewers to think about what it is like for a child to be underestimated and to struggle with a soundscape that is not perceived naturally in the realm. Deaf children have a right to be in an environment where they can gain meaningful information and thrive. The film is loaded with deaf-related symbols and themes, and its story structure is distinctly shaped by American Sign Language (ASL) poetry and written poetry. ASL storytelling is intrinsic to Deaf culture, and one of its most prominent and intense forms is ASL Poetry, which is embodied in the animation form. Ultimately, Rite of Identity portrays a metamorphosis happening while navigating the two realms and discovering ourselves, which is our rite of passage. My paper will expand on the sound experiments that contributed to the technical process and will explain how my intersectional experiences, cultural storytelling, and poetry contributed to the evolution of Rite of Identity

Evolving soft locomotion in aquatic and terrestrial environments: effects of material properties and environmental transitions

Designing soft robots poses considerable challenges: automated design approaches may be particularly appealing in this field, as they promise to optimize complex multi-material machines with very little or no human intervention. Evolutionary soft robotics is concerned with the application of optimization algorithms inspired by natural evolution in order to let soft robots (both morphologies and controllers) spontaneously evolve within physically-realistic simulated environments, figuring out how to satisfy a set of objectives defined by human designers. In this paper a powerful evolutionary system is put in place in order to perform a broad investigation on the free-form evolution of walking and swimming soft robots in different environments. Three sets of experiments are reported, tackling different aspects of the evolution of soft locomotion. The first two sets explore the effects of different material properties on the evolution of terrestrial and aquatic soft locomotion: particularly, we show how different materials lead to the evolution of different morphologies, behaviors, and energy-performance tradeoffs. It is found that within our simplified physics world stiffer robots evolve more sophisticated and effective gaits and morphologies on land, while softer ones tend to perform better in water. The third set of experiments starts investigating the effect and potential benefits of major environmental transitions (land - water) during evolution. Results provide interesting morphological exaptation phenomena, and point out a potential asymmetry between land-water and water-land transitions: while the first type of transition appears to be detrimental, the second one seems to have some beneficial effects.Comment: 37 pages, 22 figures, currently under review (journal

컴퓨터를 활용한 여러 사람의 동작 연출

학위논문 (박사)-- 서울대학교 대학원 공과대학 전기·컴퓨터공학부, 2017. 8. 이제희.Choreographing motion is the process of converting written stories or messages into the real movement of actors. In performances or movie, directors spend a consid-erable time and effort because it is the primary factor that audiences concentrate. If multiple actors exist in the scene, choreography becomes more challenging. The fundamental difficulty is that the coordination between actors should precisely be ad-justed. Spatio-temporal coordination is the first requirement that must be satisfied, and causality/mood are also another important coordinations. Directors use several assistant tools such as storyboards or roughly crafted 3D animations, which can visu-alize the flow of movements, to organize ideas or to explain them to actors. However, it is difficult to use the tools because artistry and considerable training effort are required. It also doesnt have ability to give any suggestions or feedbacks. Finally, the amount of manual labor increases exponentially as the number of actor increases. In this thesis, we propose computational approaches on choreographing multiple actor motion. The ultimate goal is to enable novice users easily to generate motions of multiple actors without substantial effort. We first show an approach to generate motions for shadow theatre, where actors should carefully collaborate to achieve the same goal. The results are comparable to ones that are made by professional ac-tors. In the next, we present an interactive animation system for pre-visualization, where users exploits an intuitive graphical interface for scene description. Given a de-scription, the system can generate motions for the characters in the scene that match the description. Finally, we propose two controller designs (combining regression with trajectory optimization, evolutionary deep reinforcement learning) for physically sim-ulated actors, which guarantee physical validity of the resultant motions.Chapter 1 Introduction 1 Chapter 2 Background 8 2.1 Motion Generation Technique 9 2.1.1 Motion Editing and Synthesis for Single-Character 9 2.1.2 Motion Editing and Synthesis for Multi-Character 9 2.1.3 Motion Planning 10 2.1.4 Motion Control by Reinforcement Learning 11 2.1.5 Pose/Motion Estimation from Incomplete Information 11 2.1.6 Diversity on Resultant Motions 12 2.2 Authoring System 12 2.2.1 System using High-level Input 12 2.2.2 User-interactive System 13 2.3 Shadow Theatre 14 2.3.1 Shadow Generation 14 2.3.2 Shadow for Artistic Purpose 14 2.3.3 Viewing Shadow Theatre as Collages/Mosaics of People 15 2.4 Physics-based Controller Design 15 2.4.1 Controllers for Various Characters 15 2.4.2 Trajectory Optimization 15 2.4.3 Sampling-based Optimization 16 2.4.4 Model-Based Controller Design 16 2.4.5 Direct Policy Learning 17 2.4.6 Deep Reinforcement Learning for Control 17 Chapter 3 Motion Generation for Shadow Theatre 19 3.1 Overview 19 3.2 Shadow Theatre Problem 21 3.2.1 Problem Definition 21 3.2.2 Approaches of Professional Actors 22 3.3 Discovery of Principal Poses 24 3.3.1 Optimization Formulation 24 3.3.2 Optimization Algorithm 27 3.4 Animating Principal Poses 29 3.4.1 Initial Configuration 29 3.4.2 Optimization for Motion Generation 30 3.5 Experimental Results 32 3.5.1 Implementation Details 33 3.5.2 Animation 34 3.5.3 3D Fabrication 34 3.6 Discussion 37 Chapter 4 Interactive Animation System for Pre-visualization 40 4.1 Overview 40 4.2 Graphical Scene Description 42 4.3 Candidate Scene Generation 45 4.3.1 Connecting Paths 47 4.3.2 Motion Cascade 47 4.3.3 Motion Selection For Each Cycle 49 4.3.4 Cycle Ordering 51 4.3.5 Generalized Paths and Cycles 52 4.3.6 Motion Editing 54 4.4 Scene Ranking 54 4.4.1 Ranking Criteria 54 4.4.2 Scene Ranking Measures 57 4.5 Scene Refinement 58 4.6 Experimental Results 62 4.7 Discussion 65 Chapter 5 Physics-based Design and Control 69 5.1 Overview 69 5.2 Combining Regression with Trajectory Optimization 70 5.2.1 Simulation and Motor Skills 71 5.2.2 Control Adaptation 75 5.2.3 Control Parameterization 79 5.2.4 Efficient Construction 81 5.2.5 Experimental Results 84 5.2.6 Discussion 89 5.3 Example-Guided Control by Deep Reinforcement Learning 91 5.3.1 System Overview 92 5.3.2 Initial Policy Construction 95 5.3.3 Evolutionary Deep Q-Learning 100 5.3.4 Experimental Results 107 5.3.5 Discussion 114 Chapter 6 Conclusion 119 6.1 Contribution 119 6.2 Future Work 120 요약 135Docto