Indiana University-Purdue University Indianapolis (IUPUI) / Khakpour, Zahra M.S.M.E., Purdue University, May 2017. Multibody Dynamics Model of A Full Human Body For Simulating Walking, Major Professor: Hazim El-Mounayri. Bipedal robotics is a relatively new research area which is concerned with creating walking robots which have mobility and agility characteristics approaching those of humans. Also, in general, simulation of bipedal walking is important in many other applications such as: design and testing of orthopedic implants; testing human walking rehabilitation strategies and devices; design of equipment and facilities for human/robot use/interaction; design of sports equipment; and improving sports performance & reducing injury. One of the main technical challenges in that bipedal robotics area is developing a walking control strategy which results in a stable and balanced upright walking gait of the robot on level as well as non-level (sloped/rough) terrains. In this thesis the following aspects of the walking control strategy are developed and tested in a high-fidelity multibody dynamics model of a humanoid body model: 1. Kinematic design of a walking gait using cubic Hermite splines to specify the motion of the center of the foot. 2. Inverse kinematics to compute the legs joint angles necessary to generate the walking gait. 3. Inverse dynamics using rotary actuators at the joints with PD (Proportional-Derivative) controllers to control the motion of the leg links. The thee-dimensional multibody dynamics model is built using the DIS (Dynamic Interactions Simulator) code. It consists of 42 rigid bodies representing the legs, hip, spine, ribs, neck, arms, and head. The bodies are connected using 42 revolute joints with a rotational actuator along with a PD controller at each joint. A penalty normal contact force model along with a polygonal contact surface representing the bottom of each foot is used to model contact between the foot and the terrain. Friction is modeled using an asperity-based friction model which approximates Coulomb friction using a variable anchor-point spring in parallel with a velocity dependent friction law. In this thesis, it is assumed in the model that a balance controller already exists to ensure that the walking motion is balanced (i.e. that the robot does not tip over). A multi-body dynamic model of the full human body is developed and the controllers are designed to simulate the walking motion. This includes the design of the geometric model, development of the control system in kinematics approach, and the simulation setup.

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There are a lot of quadruped robots in the world, but few are omnidirectional. Therefore this thesis describes the production and design process of such a robot. Examining earlier quadruped robots determined that a central microcontroller is required to control it, and servo motors are used to power the robots joints. Reaserch also determined the base of the mathematical methods used. Additionally, there are multiple types of sprawling gaits, ranging from statically stable to dynamically stable. In this project astatically stable gait is used. The thesis illustrates the mathematical models used to define the omnidirectional movement, and describes the code used to implement it. The result is a robot that can move omnidirectionally, both normally and upside down. The results show that there is a deviation depending upon the direction, but it is small. The main advantage of omnidirectionallity is the ability to change movement direction without stopping or turning. It also enables directional adjustment without requiring any steps. / Det här projektet gick ut på att skapa en krypande fyrbent robot som kan gå i alla riktningar utan att rotera runt sitt eget centrum. Det finns idag redan ett stort antal olika fyrbenta robotar, men få kan gå i alla riktningar. Därav så beskriver den här rapporten framtagningen och designprocessen för en sådan robot. Undersökning av fyrbenta robotar visade att en mikrokontroller är nödvändigför att kontrollera roboten och servomotorer bör användas för att driva lederna. Förstudeierna gav även basen för de matematiska modellerna som används for rörelserna, samt vetskapen om ett flertal olika typer av gångstilar, allt från statiskt stabil till dynamiskt stabil. I det här projektet beskrivs de matematiska modellerna som används för att definiera rörelsen i alla riktningar och hur dessa appliceras i programmeringen av roboten. Resultatet blev en robot som kan gå i alla riktningar utan att rotera runt sitt centrum, både normalt och uppochner. Detta ger möjligheten att byta rörelse riktning utan att behöva stanna eller vända sig, samt möjliggör även riktnings korrektioner utan att kräva extra steg.

Multi-robot systems (MRSs) have gained significant momentum as of late in the robotics community as they find application in tasks such as unknown environment exploration, distributed surveillance, and search and rescue. Operating robot teams in real world environments introduces a notion of uncertainty into the system, especially when it comes to the ability of the MRS to reliably communicate. This poses a significant challenge as a stable communication topology is the backbone of the team's ability to coordinate. Additionally, as these systems continue to evolve and integrate further into our society, a growing threat of adversarial attackers pose the risk of compromising nominal operation. As such, this dissertation aims to model the effects of uncertainty in communication on the topology of the MRS using a probabilistic interaction model. More specifically we are interested in studying a probabilistic perspective to those topologies that pertain to the security and resilience of an MRS against adversarial attacks. Having a model that is capable of capturing how probabilistic topologies may evolve over time is essential for secure and resilient planning under communication uncertainty. As a result, we develop probabilistic models, both exact and approximate, for the topological properties of system left-invertibility and (r, s)-robustness that respectively characterize the security and resilience of an MRS. In our modeling, we use binary decision diagrams, convolutional neural networks, matroid theory and more to tackle the problems related to probabilistic security and resilience where we find exact solutions, calculate bounds, solve optimization problems, and compute informative paths for exploration. / Doctor of Philosophy / When robots coordinate and interact together to achieve a collaborative task as a team, we obtain what is known as a multi-robot system or MRS for short. MRSs have several advantages over single robots. These include reliability through redundancy, where several robots can perform a given task in case one of the robots unexpectedly fails. The ability to work faster and more efficiently by working in parallel and at different locations. And taking on more complex tasks that can be too demanding for a single robot to complete. Unfortunately, the advantages of MRSs come at a cost, they are generally harder to coordinate, the action of one robot often depends on the action of other robots in the system, and they are more vulnerable to being attacked or exploited by malicious attackers who want to disrupt nominal operation. As one would expect, communication plays a very important roles in coordinating a team of robots. Unfortunately, robots operating in real world environments are subject to disturbances such as noise, obstacles, and interference that hinders the team's ability to effectively exchange information. In addition to being crucial in coordination, effective information exchange plays a major role in detecting and avoiding adversarial robots. Whenever misinformation is being spread in the team, the best way to counter such adversarial behavior is to communicate with as much well-behaving robots as possible to identity and isolate inconsistencies. In this dissertation we try to study how uncertainty in communication affects a system's ability to detect adversarial behavior, and how we can model such a phenomenon to help us account for these uncertainties when designing secure and resilient multi-robot systems.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第25433号 / 情博第871号 / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 神田 崇行, 教授 伊藤 孝行, 教授 緒方 広明 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DGAM

Human-controlled robots are utilized in many situations and such use is becoming widespread. This thesis details research that allows a single human to interact with a team of robots performing tasks that require cooperation. The research provides insight into effective interaction design methods and appropriate interface techniques. The use of team-level autonomy is shown to decrease human workload while simultaneously improving individual robot efficiency and robot-team cooperation. An indoor human-robot interaction testbed was developed at the BYU MAGICC Lab to facilitate experimentation. The testbed consists of eight robots equipped with wireless modems, a field on which the robots move, an overhead camera and image processing software which tracks robot position and heading, a simulator which allows development and testing without hardware utilization and a graphical user interface which enables human control of either simulated or hardware robots. The image processing system was essential for effective robot hardware operation and is described in detail. The system produced accurate robot position and heading information 30 times per second for a maximum of 12 robots, was relatively insensitive to lighting conditions and was easily reconfigurable. The completed testbed was utilized to create a game for testing human-robot interaction schemes. The game required a human controlling three robots to find and tag three robot opponents in a maze. Finding an opponent could be accomplished by individual robots, but tagging an opponent required cooperation between at least two robots. The game was played by 11 subjects in five different autonomy modes ranging from limited robot autonomy to advanced individual autonomy with basic team-level autonomy. Participants were interrupted during the game by a secondary spatial reasoning task which prevented them from interacting with the robots for short periods of time. Robot performance during that interruption provided a measure of both individual and team neglect tolerance. Individual robot neglect tolerance and performance did not directly correspond to those quantities at the team level. The interaction mode with the highest levels of individual and team autonomy was most effective; it minimized game time and human workload and maximized team neglect tolerance.

A collaborative robot is something of growing interest for companies in the manufacturing industries to implement. However, a collaborative robot is quite new in today’s market. An issue that arises is that no implementation process for collaborative robots exists today, as well as no requirement guide for skills, as well as actors, has been defined. The aim of this project was to examine how an implementation process of collaborative robots in manufacturing companies could look like. Focusing on charting the integration process steps of a collaborative robot, and identifying the actors as well as skills needed for successful cobot integration, with the aim achieve the goal of this thesis by answering the research questions. The thesis had the following research questions: Research Question 1 – How is an integration process for implementing a cobot represented in the manufacturing companies? Research Question 2 – What particular skills as well as actors are required when implementing in a cobot in the manufacturing companies? To answer the research questions, the author conducted several interviews with different companies. The interview questions were mainly constructed in order to answer the RQs but also to get an understanding for the different aspects of what a cobot is, what is required as well as how it compares to a traditional industrial robot. The thesis resulted in an implementation process with several steps constructed in order to implement a cobot as well as different aspects of what skills and actors are needed. In order to separate the aspects, the respondents were categorized into different roles which are the developer, integrator and the user. The different roles were all vital, providing an understanding from different perspectives. Keywords: Collaborative robot, cobot, Human-robot interaction, Human-Robot Collaboration, Development strategies, Automation, Industry 4.0.