Planning And Control Of Swarm Motion As Continua

In this thesis, new algorithms for formation control of multi agent systems (MAS) based on continuum mechanics principles will be investigated. For this purpose agents of the MAS are treated as particles in a continuum, evolving in an n-D space, whose desired configuration is required to satisfy an admissible deformation function. Considered is a specific class of mappings that is called homogenous where the Jacobian of the mapping is only a function of time and is not spatially varying. The primary objectives of this thesis are to develop the necessary theory and its validation via simulation on a mobile-agent based swarm test bed that includes two primary tasks: 1) homogenous transformation of MAS and 2) deployment of a random distribution of agents on to a desired configuration. Developed will be a framework based on homogenous transformations for the evolution of a MAS in an n-D space (n=1, 2, and 3), under two scenarios: 1) no inter-agent communication (predefined motion plan); and 2) local inter-agent communication. Additionally, homogenous transformations based on communication protocols will be used to deploy an arbitrary distribution of a MAS on to a desired curve. Homogenous transformation with no communication: A homogenous transformation of a MAS, evolving in an space, under zero inter agent communication is first considered. Here the homogenous mapping, is characterized by an n x n Jacobian matrix ( ) and an n x 1 rigid body displacement vector ( ), that are based on positions of n+1 agents of the MAS, called leader agents. The designed Jacobian ( ) and rigid body displacement vector ( ) are passed onto rest of the agents of the MAS, called followers, who will then use that information to update their positions under a pre- iv defined motion plan. Consequently, the motion of MAS will evolve as a homogenous transformation of the initial configuration without explicit communication among agents. Homogenous Transformation under Local Communication: We develop a framework for homogenous transformation of MAS, evolving in , under a local inter agent communication topology. Here we assume that some agents are the leaders, that are transformed homogenously in an n-D space. In addition, every follower agent of the MAS communicates with some local agents to update its position, in order to grasp the homogenous mapping that is prescribed by the leader agents. We show that some distance ratios that are assigned based on initial formation, if preserved, lead to asymptotic convergence of the initial formation to a final formation under a homogenous mapping. Deployment of a Random Distribution on a Desired Manifold: Deployment of agents of a MAS, moving in a plane, on to a desired curve, is a task that is considered as an application of the proposed approach. In particular, a 2-D MAS evolution problem is considered as two 1-D MAS evolution problems, where x or y coordinates of the position of all agents are modeled as points confined to move on a straight line. Then, for every coordinate of MAS evolution, bulk motion is controlled by two agents considered leaders that move independently, with rest of the follower agents motions evolving through each follower agent communicating with two adjacent agents

Nonsingular formation control of cooperative mobile robots via feedback linearization

This paper addresses the control of a leader-follower formation where the leader robot has its own target and the follower robots are constrained by the specified formation tasks. The dynamics of the leader robot with nonholonomic constraint is explicitly integrated into the formation system to yield a centralized coordinating controller. As a result there is no need to assume the motion of the leader separatively when we develop cooperative formation controllers for coordinating the robots. The feedback linearization is used to deal with the nonlinear formation control of a team of autonomous mobile robots with nonholonomic constraints. Although the nonlinear formation system under consideration can be exactly linearized by taking advantage of dynamic feedback linearization, there exists structural singularity which may pose serious problems in practice. To solve this singular problem a new formation model for controlling the leader-follower formation in a cooperative manner is developed. This new formation model can be extended to studying other control and learning issues in multi-robot systems for both cooperation and noncooperation. The internal dynamics is derived and proven to be globally stable under the stable linear controller obtained via the partially linearized dynamics. To demonstrate the performance of the developed formation controller, simulation results are provided

多対象物のトラッキングとそのハエ行動解析への応用

Tohoku University橋本浩一課

A cooperative advanced driver assistance and safety system for connected and automated vehicles

Konfliktsituationen mit mehreren Beteiligten sind für Fahrzeugführer und konventionelle Fahrerassistenz- und Sicherheitssysteme durch ihre hohe Komplexität schwer beherrschbar. So geschehen viele Unfälle auf den Straßen dieser Welt, die durch gemeinschaftlich abgestimmte Fahrmanöver verhindert oder in ihren Unfallfolgen gemindert werden könnten. Die vorliegende Arbeit adressiert dieses Potenzial und beschäftigt sich mit der Entwicklung und prototypischen Umsetzung eines fahrzeugübergreifenden kooperativen Fahrerassistenz- und Sicherheitssystems, welches mehrere Fahrzeuge über eine funkbasierte Kommunikation miteinander verbindet, sowie unfallfreie Lösungen berechnet und durchführt. In diesem Zusammenhang werden drei Forschungsfragen aufgestellt, die eine Definition von kooperativem Verhalten, eine Methode zur Koordination der anfallenden Aufgaben (Aufgabenkoordination) und eine Methode zur gemeinsamen Fahrmanöverplanung (Fahrmanöverkoordination) adressieren. Der Stand der Wissenschaft und Technik bezüglich der Forschungsfragen wird mithilfe einer systematischen Literaturstudie ermittelt, die für den Leser in einem Überblick dargestellt und hinsichtlich einer möglichen Beantwortung der Forschungsfragen ausgewertet wird. Es zeigt sich, dass die drei Forschungsfragen mit ihren Anforderungen bislang unbeantwortet sind. Zur Definition von kooperativem Verhalten werden Eigenschaften von diesem aufgezeigt, die in notwendige und hinreichende Bedingungen überführt werden. Mit der zusätzlichen Berücksichtigung von Reziprozität ergibt sich eine Definition von kooperativem Verhalten, welche durch die Steigerung des Gesamtnutzens die Unterscheidung zwischen unkooperativem Verhalten auf der einen Seite und rational-kooperativem, altruistisch-kooperativem bzw. egoistisch-kooperativem Verhalten auf der anderen Seite ermöglicht. Ein Vergleich mit den aus dem Stand der Technik bekannten Definitionen zeigt den Neuigkeitswert der entwickelten Definition. In ausgewählten Situationen wird die Definition in Simulationen angewandt.Critical situations involving multiple vehicles are rarely controlled by the associated drivers. This is one reason for the remaining number of accidents which could possibly be prevented or at least mitigated with jointly planned and conducted driving maneuvers. This potential is addressed in the dissertation at hand by developing a prototypical cooperative driver assistance and safety system coordinating multiple vehicles cooperatively using vehicle-to-vehicle-communication. In this context, three research questions reflect challenges on the road towards such a system. The research questions deal with defining a cooperative behavior, creating a method allowing to allocate coordinative tasks (task coordination), and generating a method enabling to plan joint cooperative maneuvers (maneuver coordination). Regarding the proposed research questions, a systematic literature review reveals the state-of-the-art which is first presented in an overview and afterwards used to derive open issues. The result is that the three research questions remain relevant and unanswered. In order to define cooperative behavior, properties are identified and categorized in sufficient and necessary conditions. An additional consideration of reciprocity enables the derivation of a definition of cooperative behavior which aims to increase the total utility. Cooperative behavior may further be separated into rational-cooperative, altruistic-cooperative, and egoistic-cooperative behavior. A comparison with known definitions of the state-of-the-art demonstrates the innovation of the novel definition, which is applied in chosen situations