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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

Coverage path planning for UAVs in search missions

Navarro, Alonso, Haracic, Avdo January 2024 (has links)
A time-effective coverage path can be decisive in catastrophic and war scenarios for saving countless lives where UAVs are used to scan an area looking for an objective. Given an area shaped as a polygon, a quadratic decomposition method is used to discretize the area into nodes. A model of the optimization problem constraint is created and solved using mixed-integer linear programming, taking into consideration simple dynamics and coverage path planning definitions. Simulations in different scenarios are presented, showing that the presence of no-fly zones can negatively affect the coverage time. The relationship between coverage time and the number of UAVs employed is nonlinear and converges to a constant value. The result has a direct impact on the evaluation of benefits and the cost of adding UAVs to a search mission.
2

Multi-UAV Coverage Path Planning for Reconstruction of 3D Structures

Shyam Sundar Kannan (6630713) 16 October 2019 (has links)
<div>Path planning is the generation of paths for the robots to navigate based on some constraints. Coverage path planning is where the robots needs to cover an entire work space for various applications like sensing, inspection and so on. Though there are numerous works on 2D coverage and also coverage using a single robot, the works on 3D coverage and multi-agents are very limited. This thesis makes several contributions to multi-agent path planning for 3D structures.</div><div><br></div><div>Motivated by the inspection of 3D structures, especially airplanes, we present a 3D coverage path planning algorithm for a multi-UAV system. We propose a unified method, where the viewpoints selection and path generation are done simultaneously for multiple UAVs. The approach is scalable in terms of number of UAVs and is also robust to models with variations in geometry. The proposed method also distributes the task uniformly amongst the multiple UAVs involved and hence making the best use of the robotics team. The uniform task distribution is an integral part of the path planner. Various performance measures of the paths generated in terms of coverage, path length and time also has been presented. </div>
3

Path Planning for Variable Scrutiny Multi-Robot Coverage

Bradner, Kevin M. 29 May 2020 (has links)
No description available.
4

Coverage Motion Planning for Search and Rescue Missions : A Costmap Based Approach for fixed wing UAVs using Simulated Annealing &amp;Cubic Splines

Rönnkvist, Fredrik January 2023 (has links)
The present study proposes a novel approach to Coverage Path Planning for unmanned aerial vehicle (UAV) inspired by the Orienteering Problem. The main goal is to develop an algorithm suitable for Search and Rescue Missions, which can produce a search pattern with dynamical constrains, that is not limited to the traditional back-and-forth motion or spiral patterns. This method leads to a more flexible and diverse coverage of the Area of Interest. In order to generate dynamically correct trajectories, we utilize cubic splines as motion primitives to solve the Orienteering Problem. To accomplish this, we implement and test three different types of cubic splines, namely Catmull-Rom, Freya, and B-splines. To determine the coverage of the search area, the sensor's projection (footprint) is evaluated along the spline trajectory onto a costmap. This method accounts for the footprint's orientation and size, which depend on the UAV's attitude to some extent. This version of the Orienteering Problem using splines for dynamical control and calculating coverage, we call the Mapping Motion Orienteering Problem (MMOP). \\The heuristic method Simulated Annealing is used to address the combinatorial challenges of the MMOP, and two cost functions are tested for optimization. The study shows that the choice of spline has a significant impact on the algorithm's efficacy, and B-splines are the most effective in generating dynamic and adaptable trajectories. However, the study also shows that the Simulated Annealing algorithm with identical settings produced varied resulting paths. Finally, further research is needed to solve the challenges faced with the computational time, which heavily depends on factors such as the sampling rate for the footprint along the path and the resolution of the costmap and footprint itself.
5

Coverage Path Planning in Large-scale Multi-floor Urban Environments : with Applications to Autonomous Road Sweeping / Körvägsplanering i storskaliga och flervåniga stadsmiljöer medtillämpningar mot autonom robotsopning

Engelsons, Daniel January 2021 (has links)
Autonomous lawn mowers and floor cleaning robots are today easily accessible and areutilizing well-studied Coverage Path Planning algorithms. They operate in single-floorenvironments that are small with simple geometry compared to general urban environments such as city parking garages, highway bridges or city crossings. A next step for autonomous cleaning is road sweeping of these complex urban environments. In this work,a new Coverage Path Planning approach, Sampled BA* &amp; Inward Spiral , handling this taskwas compared with existing well-performing algorithms BA* and Inward Spiral. The proposed approach combines the strengths of existing algorithms and demonstrates state-of-the-art performance on three large-scale 3D environments. It generated paths with lessrotation, while keeping the length of the path on the same level. For a given starting point,the new approach had consistently lower cost (length + rotation) for all environments. Forrandom starting points, randomness in the new approach caused less robustness, givingsignificantly higher cost. To improve the performance of the algorithms and remove biasfrom manual tuning, the parameters were automatically tuned using Bayesian Optimization. This makes the evaluation more robust and the results stronger.
6

Path Planning for a UAV in an Agricultural Environment to Tour and Cover Multiple Neighborhoods

Sinha, Koel 20 October 2017 (has links)
This work focuses on path planning for an autonomous UAV to tour and cover multiple regions in the shortest time. The three challenges to be solved are - finding the right optimal order to tour the neighborhoods, determining entry and exit points to neighborhoods, and covering each neighborhood. Two approaches have been explored and compared to achieve this goal - a TSP - Greedy and TSP - Dijkstra's. Both of them use a TSP solution to determine the optimal order of touring. They also use the same back and forth motion to cover each region. However, while the first approach uses a brute force to determine the the next closest node of entry or exit, the second approach utilizes the Dijkstra's algorithm to compute all possible paths to every node in the graph, and therefore choose the shortest pairs of entry and exit for each region, that would generate the shorter path, overall. The main contribution of this work is to implement an existing algorithm to combine the touring and covering problem, and propose a new algorithm to perform the same. Empirical results comparing performances of both approaches are included. Hardware experiments are performed on a spraying hexacopter, using the TSP - Greedy approach. Unique system characteristics are studied to make conclusions about stability of the platform. Future directions are identified to improve both software and hardware performance. / Master of Science / In a world with a rapidly growing population and resources depleting faster, increasing efficiency and productivity has become paramount. Until now, automation has helped cope with the world’s increasing demand for food. However, studies have shown that automation in itself will be insufficient in improving crop output in the coming years. Fortunately, another technology that is taking big leaps in terms of technological advances - Information Technology, when combined with automation, presents itself as a viable option. This takes agriculture towards a site-specific approach for all crop monitoring, growth and protection activities and is know as Precision Agriculture. Spraying fluids on crops using a UAV is on of the prominent problems being researched in this field. This work presents two approaches - TSP - Greedy and TSP - Dijkstra’s to tour or visit and spray multiple regions that have been previously identified in the shortest time. While the TSP - Greedy algorithm is an implementation of an existing approach, the TSP - Dijkstra’s algorithm is a new approach proposed in this work. The solution to TSP or Traveling Salesman Problem generates the optimal order to visit the regions. The ’Greedy’ or ’Dijsktra’s’ approaches define entry and exit points for each region, that gives the shortest path overall. Images of areas with weed afflicted regions marked on them are used as the input for this algorithm. The TSP-Greedy approach is used in performing hardware experiments. Data collected from these experiments are used to analyze performance of an Unmanned Aerial Vehicle (UAV) platform. Water has been used as the spraying fluid for testing the sprayer assembly. GPS or Global Positioning System is used for navigation of the UAV. Future directions are identified to improve both software and hardware performance.
7

Plánování trasy pro autonomní robotickou sekačku / Coverage Path Planning for Autonomous Robotic Lawn Mower

Moninec, Michal January 2021 (has links)
This diploma thesis is covering the coverage path planning problem for autonomous robotic lawn mower in an area, which is fully defined before and is not changing. It contains a review of the currently used methods and an implementation of a software with a graphic user interface, which is capable of generating optimalized path.
8

Safety-aware autonomous robot navigation, mapping and control by optimization techniques

Lei, Tingjun 08 December 2023 (has links) (PDF)
The realm of autonomous robotics has seen impressive advancements in recent years, with robots taking on essential roles in various sectors, including disaster response, environmental monitoring, agriculture, and healthcare. As these highly intelligent machines continue to integrate into our daily lives, the pressing imperative is to elevate and refine their performance, enabling them to adeptly manage complex tasks with remarkable efficiency, adaptability, and keen decision-making abilities, all while prioritizing safety-aware navigation, mapping, and control systems. Ensuring the safety-awareness of these robotic systems is of paramount importance in their development and deployment. In this research, bio-inspired neural networks, nature-inspired intelligence, deep learning, heuristic algorithm and optimization techniques are developed for safety-aware autonomous robots navigation, mapping and control. A bio-inspired neural network (BNN) local navigator coupled with dynamic moving windows (DMW) is developed in this research to enhance obstacle avoidance and refines safe trajectories. A hybrid model is proposed to optimize trajectory of the global path of a mobile robot that maintains a safe distance from obstacles using a graph-based search algorithm associated with an improved seagull optimization algorithm (iSOA). A Bat-Pigeon algorithm (BPA) is proposed to undertake adjustable speed navigation of autonomous vehicles in light of object detection for safety-aware vehicle path planning, which can automatically adjust the speed in different road conditions. In order to perform effective collision avoidance in multi-robot task allocation, a spatial dislocation scheme is developed by introduction of an additional dimension for UAVs at different altitudes, whereas UAVs avoid collision at the same altitude using a proposed velocity profile paradigm. A multi-layer robot navigation system is developed to explore row-based environment. A directed coverage path planning (DCPP) fused with an informative planning protocol (IPP) method is proposed to efficiently and safely search the entire workspace. A human-autonomy teaming strategy is proposed to facilitate cooperation between autonomous robots and human expertise for safe navigation to desired areas. Simulation, comparison studies and on-going experimental results of optimization algorithms applied for autonomous robot systems demonstrate their effectiveness, efficiency and robustness of the proposed methodologies.

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