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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Perception and Planning of Connected and Automated Vehicles

Mangette, Clayton John 09 June 2020 (has links)
Connected and Automated Vehicles (CAVs) represent a growing area of study in robotics and automotive research. Their potential benefits of increased traffic flow, reduced on-road accident, and improved fuel economy make them an attractive option. While some autonomous features such as Adaptive Cruise Control and Lane Keep Assist are already integrated into consumer vehicles, they are limited in scope and require innovation to realize fully autonomous vehicles. This work addresses the design problems of perception and planning in CAVs. A decentralized sensor fusion system is designed using Multi-target tracking to identify targets within a vehicle's field of view, enumerate each target with the lane it occupies, and highlight the most important object (MIO) for Adaptive cruise control. Its performance is tested using the Optimal Sub-pattern Assignment (OSPA) metric and correct assignment rate of the MIO. The system has an average accuracy assigning the MIO of 98%. The rest of this work considers the coordination of multiple CAVs from a multi-agent motion planning perspective. A centralized planning algorithm is applied to a space similar to a traffic intersection and is demonstrated empirically to be twice as fast as existing multi-agent planners., making it suitable for real-time planning environments. / Master of Science / Connected and Automated Vehicles are an emerging area of research that involve integrating computational components to enable autonomous driving. This work considers two of the major challenges in this area of research. The first half of this thesis considers how to design a perception system in the vehicle that can correctly track other vehicles and assess their relative importance in the environment. A sensor fusion system is designed which incorporates information from different sensor types to form a list of relevant target objects. The rest of this work considers the high-level problem of coordination between autonomous vehicles. A planning algorithm which plans the paths of multiple autonomous vehicles that is guaranteed to prevent collisions and is empirically faster than existing planning methods is demonstrated.
2

Identifying Critical Regions for Robot Planning Using Convolutional Neural Networks

January 2019 (has links)
abstract: In this thesis, a new approach to learning-based planning is presented where critical regions of an environment with low probability measure are learned from a given set of motion plans. Critical regions are learned using convolutional neural networks (CNN) to improve sampling processes for motion planning (MP). In addition to an identification network, a new sampling-based motion planner, Learn and Link, is introduced. This planner leverages critical regions to overcome the limitations of uniform sampling while still maintaining guarantees of correctness inherent to sampling-based algorithms. Learn and Link is evaluated against planners from the Open Motion Planning Library (OMPL) on an extensive suite of challenging navigation planning problems. This work shows that critical areas of an environment are learnable, and can be used by Learn and Link to solve MP problems with far less planning time than existing sampling-based planners. / Dissertation/Thesis / Masters Thesis Computer Science 2019
3

Towards Manipulator Task-Oriented Programming: Automating Behavior-Tree Configuration

Yue Cao (18985100) 08 July 2024 (has links)
<p dir="ltr">Task-oriented programming is a way of programming manipulators in terms of high-level tasks instead of explicit motions. It has been a long-standing vision in robotics since its early days. Despite its potential, several challenges have hindered its full realization. This thesis identifies three major challenges, particularly in task specification and the planning-to-execution transition: 1) The absence of natural language integration in system input. 2) The dilemma of continuously developing non-uniform and domain-specific primitive-task libraries. 3) The requirement for much human intervention.</p><p dir="ltr">To overcome these difficulties, this thesis introduces a novel approach that integrates natural language inputs, eliminates the need on fixed primitive-task libraries, and minimizes human intervention. It adopts the behavior tree, a modular and user-friendly form, as the task representation and advances its usage in task specification and planning-to-execution transition. The thesis is structured into two parts – Task Specification and Planning-to-Execution Transition.</p><p dir="ltr">Task specification explores the use of large language models to generate a behavior tree from an end-user's input. A Phase-Step prompt is designed to enable the automatic behavior-tree generation from end-user's abstract task descriptions in natural languages. With the powerful generalizability of large language models, it breaks the dilemma that stays with fixed primitive-task libraries in task generation. A full-process case study demonstrated the proposed approach. An ablation study was conducted to evaluate the effectiveness of the Phase-Step prompts. Task specification also proposes behavior-tree embeddings to facilitate the retrieval-augmented generation of behavior trees. The integration of behavior-tree embeddings not only eliminates the need for manual prompt configuration but also provides a way to incorporate external domain knowledge into the generation process. Three types of evaluations were performed to assess the performance of the behavior-tree embedding method.</p><p dir="ltr">Planning-to-execution transition explores how to transit primitive tasks from task specification into manipulator executions. Two types of primitive tasks are considered separately: point-to-point movement tasks and object-interaction tasks. For point-to-point movement tasks, a behavior-tree reward is proposed to enable reinforcement learning over low-level movement while following high-level running order of the behavior tree. End-users only need to specify rewards on the primitive tasks over the behavior tree, and the rest of the process will be handled automatically. A 2D space movement simulation was provided to justify the approach. For object-interaction tasks, the planning-to-execution transition uses a large-language-model-based generation approach. This approach takes natural-language-described primitive tasks as input and directly produces task-frame-formalism set-points. Combined with hybrid position/force control systems, a transition process from primitive tasks directly into joint-level execution can be realized. Evaluations over a set of 30 primitive tasks were conducted.</p><p dir="ltr">Overall, this thesis proposes an approach that advances the behavior-tree towards automated task specification and planning-to-execution transitions. It opens up new possibilities for building better task-oriented manipulator programming systems.</p>
4

A Comparision Study for Robot Planning Automation Between CATIA V5 &amp; 3D Experience

Rimmalapudi, Veera Venkata Manikanta Virupaksha Raja Chowdary, Acharya, Vinayak Ramachandra January 2021 (has links)
As the world is evolving very fast with the developments of new technologies and softwares in design and manufacturing, business organizations and manufacturing industries will always be adapting to the new technologies and softwares for increasing the cost and time efficiency in the development of products. So, this thesis focuses on a comparative study between two Dassault Systems softwares in which, one is mostly used CAD software by industries for a long time, and one is the latest developments in the CAD softwares with satisfying business requirements. For this comparison study, the two methods called design automation and robot simulation are used in the development of modular fixtures platforms used in automobile manufacturing industries. In the first method, the design and assembly of modular fixtures platform are done which holds the automotive car sheet pillars together. With a single mouse click, the complete design and assembly of the modular fixtures can be done using automation. In the second method, the spot-welding manufacturing operation is done to join the car sheet pillars together to produce the B-pillar of the Body in white (BIW) for the automobile, with the help of a welding gun connected to ABB robot arm, using automation in robot simulation. This work takes place in CATIA V5 and 3D Experience, and the final results obtained in both the software are compared and discussed in the results part of this report. Automation in CAD has been one of the advanced developments that happened in the 21st century through which most of the engineering knowledge and intent can be captured and reutilized. CATIA V5 &amp; 3D Experience Automation is done using two programming languages called VB (Visual Basics) and VB.net.

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