Engineering Commons^™

Data-Driven Porosity Prediction For Directed Energy Deposition, Georgia E. Kaufman

Electrical and Computer Engineering ETDs

Stochastic flaw formation leading to poor print quality is a major obstacle to the utility of directed energy deposition (DED), a laser and metal powder-based additive manufacturing technology for construction and repair of custom metal parts. While melt pool temperature variability is known to be a major factor in flaw formation, control schemes to decrease flaw formation are limited by a lack of physics-based models that fully and accurately describe DED. In this work, a stochastic reachability analysis with a data-driven model based on thermal images of the melt pool was conducted to determine the likelihood of violating melt pool …

Data-Driven Stochastic Optimal Control Using Hilbert Space Embeddings Of Distributions, Adam J. Thorpe

Electrical and Computer Engineering ETDs

Autonomous systems are increasingly being deployed in complex environments subject to real-world uncertainty. For such systems, it may be exceptionally difficult or even impossible to compute a simple mathematical model of the system--for instance due to the presence of human elements, complex mechanics or system dynamics, or learning-enabled components. Data-driven control has recently gained significant attention in this area, where observations taken from the system evolution are used to compute an implicit representation of the system that is amenable to analysis and control. However, data-driven algorithms for control present new challenges, and require new insights to enable their use. The …

Vision-Based Autonomous Tracking Of A Non-Cooperative Mobile Robot By A Low-Cost Quadrotor Vehicle, Cheikhna Ahmed Tidiane Sy

Electrical and Computer Engineering ETDs

The goal of this thesis is the detection and tracking of a ground vehicle, in particular a car-like robot, by a quadrotor. The first challenge to address in any pursuit or tracking scenario is the detection and unique identification of the target. From this first challenge, comes the need to precisely localize the target in a coordinate system that is common to the tracking and tracked vehicles. In most real-life scenarios, the tracked vehicle does not directly communicate information such as its position to the tracking one. From this fact, arises a non-cooperative constraint problem. The autonomous tracking aspect of …

Verification Of Stochastic Reach-Avoid Using Rkhs Embeddings, Adam J. Thorpe

Electrical and Computer Engineering ETDs

A solution to the terminal-hitting and first-hitting stochastic reach-avoid problem for a Markov control process is presented. This solution takes advantage of a nonparametric representation of the stochastic kernel as a conditional distribution embedding within a reproducing kernel Hilbert space (RKHS). Because the disturbance is modeled as a data-driven stochastic process, this representation avoids intractable integrals in the dynamic recursion of the reach-avoid problem since the expectations can be calculated as an inner product within the RKHS. An example using a high-dimensional chain of integrators is presented, as well as for Clohessy-Wiltshire-Hill (CWH) dynamics.

Ros-Enabled Framework For A Miniature Hexapod As A Mobile Robot Research Platform, Joseph Michael Kloeppel

Electrical and Computer Engineering ETDs

The purpose of this thesis is to investigate and develop a framework for connected six-legged robots which can be used as a Robotic Operating System (ROS) based research platform. The research presented aims to purvey the necessary engineering and scientific steps needed to evolve a consumer-grade connected toy into a fully functioning and highly capable robotic system. Such a platform can be used to simulate and implement novel biologically inspired swarm research. Crawling robots have the advantage of being able to scale terrains which wheeled mobile robots may not and possess many interesting characteristics. The miniROaCH, miniature ROS-enabled and Crawling …

Ros Based High Performance Control Architecture For An Aerial Robotic Testbed, Christoph Hintz

Electrical and Computer Engineering ETDs

The purpose of this thesis is to show the development of an aerial testbed based on the Robot Operating System (ROS). Such a testbed provides flexibility to control heterogenous vehicles, since the robots are able to simply communication with each other on the High Level (HL) control side. ROS runs on an embedded computer on-board each quadrotor. This eliminates the need of a Ground Base Station, since the complete HL control runs on-board the Unmanned Aerial Vehicle (UAV).

The architecture of the system is explained throughout the thesis with detailed explanations of the specific hardware and software used for the …