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1
Chen, Yuanyan. "Autonomous Unmanned Ground Vehicle (UGV) Follower Design." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1470951910.
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Teresi, Michael Bryan. "Multispectral Image Labeling for Unmanned Ground Vehicle Environments." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/53998.
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Described is the development of a multispectral image labeling system with emphasis on Unmanned Ground Vehicles(UGVs). UGVs operating in unstructured environments face significant problems detecting viable paths when LIDAR is the sole source for perception. Promising advances in computer vision and machine learning has shown that multispectral imagery can be effective at detecting materials in unstructured environments [1][2][3][4][5][6]. This thesis seeks to extend previous work[6][7] by performing pixel level classification with multispectral features and texture. First the images are spatially registered to create a multispectral image cube. Visual, near infrared, shortwave infrared, and visible/near infrared polarimetric data are considered. The aligned images are then used to extract features which are fed to machine learning algorithms. The class list includes common materials present in rural and urban scenes such as vehicles, standing water, various forms of vegetation, and concrete. Experiments are conducted to explore the data requirement for a desired performance and the selection of a hyper-parameter for the textural features. A complete system is demonstrated, progressing from the data collection and labeling to the analysis of the classifier performance.Master of Science
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Wagner, Anthony Julian. "Online Unmanned Ground Vehicle Mission Planning using Active Aerial Vehicle Exploration." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90785.
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This work presents a framework for the exploration and path planning for a collaborative
UAV and UGV system. The system is composed of a UAV with a stereo system for obstacle
detection and a UGV with no sensors for obstacle detection. Two exploration algorithms
were developed to guide the exploration of the UAV. Both identify frontiers for exploration
with the Dijkstra Frontier method using Dijkstra's Algorithm to identify a frontier with
unknown space, and the other uses a bi-directional RRT to identify multiple frontiers for
selection. The final algorithm developed was for to give the UGV partial plans when an entire
plan is not yet found. This improves the overall mission tempo. The algorithm is designed
to keep the UGV a safe distance from the unknown frontier to prevent backtracking. All the
algorithms were tested in Gazebo using the ROS framework. The Dijkstra Frontier method
was also tested on the hardware system. The results show the RRT Explore algorithm to
work well for exploring the environment, performing equally or better than the Dijkstra
Frontier method. The UGV partial plan method showed a decreased traveled distance for
the UGV but increases in UGV mission time with more conservative distances from danger.
Overall, the framework showed a good exploration of the environment and performs the
intended missions.Master of Science
This work presents a framework for the exploration and path planning for a collaborative aerial and ground vehicle robotic system. The system is composed of an aircraft with a camera system for obstacle detection and a ground vehicle with no sensors for obstacle detection. Two exploration algorithms were developed to guide the exploration of the aircraft. Both identify frontiers for exploration with the Dijkstra Frontier method using path planning algorithms to identify a frontier with unknown space (Dijkstra Frontier), and the other uses a sampling based path planning method (RRT Explore) to identify multiple frontiers for selection. The final algorithm developed was for to give the ground vehicle intermediate plans when an entire plan is not yet found. The algorithm is designed to keep the ground vehicle a safe distance from the unknown frontier to prevent backtracking. All the algorithms were tested in a simulation framework using Robot Operating System and one exploration method was tested on the hardware system. The results show the RRT Explore algorithm to work well for exploring the environment, performing equally or better than the Dijkstra Frontier method. The ground vehicle intermediate plan method showed a decreased traveled distance for the ground vehicle but increases in ground vehicle mission time with more conservative distances from danger. Overall, the framework showed a good exploration of the environment and performs the intended missions.
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Kirsch, Patricia Jean. "Autonomous swarms of unmanned vehicles software control system and ground vehicle testing /." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2993.
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Thesis (M.S.) -- University of Maryland, College Park, 2005.Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Källström, Alexander, and Jagesten Albin Andersson. "Autonomous Landing of an Unmanned Aerial Vehicle on an Unmanned Ground Vehicle in a GNSS-denied scenario." Thesis, Linköpings universitet, Reglerteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-167924.
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An autonomous system consisting of an unmanned aerial vehicle (UAV) in cooperation with an unmanned ground vehicle (UGV) is of interest in applications for military reconnaissance, surveillance and target acquisition (RSTA). The basic idea of such a system is to take advantage of the vehicles strengths and counteract their weaknesses. The cooperation aspect suggests that the UAV is capable of autonomously landing on the UGV. A fundamental part of the landing is to localise the UAV with respect to the UGV. Traditional navigation systems utilise global navigation satellite system (GNSS) receivers for localisation. GNSS receivers have many advantages, but they are sensitive to interference and spoofing. Therefore, this thesis investigates the feasibility of autonomous landing in a GNSS-denied scenario. The proposed landing system is divided into a control and an estimation system. The control system uses a proportional navigation (PN) control law to approach the UGV. When sufficiently close, a proportional-integral-derivative (PID) controller is used to match the movements of the UGV and perform a controlled descent and landing. The estimation system comprises an extended Kalman filter that utilises measurements from a camera, an imu and ultra-wide band (UWB) impulse radios. The landing system is composed of various results from previous research. First, the sensors used by the landing system are evaluated experimentally to get an understanding of their characteristics. The results are then used to determine the optimal sensor placements, in the design of the EKF, as well as, to shape the simulation environment and make it realistic. The simulation environment is used to evaluate the proposed landing system. The combined system is able to land the UAV safely on the moving UGV, confirming a fully-functional landing system. Additionally, the estimation system is evaluated experimentally, with results comparable to those obtained in simulation. The overall results are promising for the possibility of using the landing system with the presented hardware platform to perform a successful landing.
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Berglund, Daniel. "Development of an Unmanned Ground Vehicle (UGV) user interface." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-80419.
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Examensarbetet syftar till att konstruera operatörsgränssnittet till en UGV (eng Unmanned Ground Vehicle) för mobil rekognosering i tätbebyggt område. Operatörsgränssnittet består av både mjuk- och hårdvara. Till operatörsgränssnittet har ett grafiskt användargränssnitt utvecklats där tonvikten legat på användbarhet med funktionalitet för positionering med geografisk presentation och sensorpresentation. Förutom en presentationsenhet för sensorinteraktion och manövrering av farkost ingår en sändtagarenhet för kommunikation mellan operatör och farkost. Två uppsättningar av systemet levererades till försvarsmakten för användning vid metodförsöksstudier.The purpose of this thesis is to develop the user interface for a UGV (Unmanned Ground Vehicle) intended for mobile reconnaissance in urban areas. The operator interface consists of both soft- and hardware. As a part, a graphical user interface has been developed with emphasis on usability including functionality for positioning with geographical presentation as well as sensor presentation. In addition to a display unit for sensor interaction and manoeuvring of the vehicle, the user interface includes a transceiver unit that handles the operator and vehicle intercommunication. Two sets of the system were delivered to the Swedish armed forces to be used in trials.
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Al-Mayyahi, Auday Basheer Essa. "Motion control of unmanned ground vehicle using artificial intelligence." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/76665/.
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The aim of this thesis is to solve two problems: the. trajectory tracking and navigation, for controlling the motion of unmanned ground vehicles (UGV). Such vehicles are usually used in industry for assisting automated production process or delivery services to improve and enhance the quality and efficiency. With regard to the trajectory tracking problem, the main task is to design a new method that is capable of minimising trajectory-tracking errors in UGV. To achieve this, a comprehensive mathematical model needs to be established that contains kinematic and dynamic characteristics beside actuators. In addition, different trajectories need to be generated and applied individually as a reference input, i.e. continuous gradient trajectories such as linear, circular and lemniscuses or a non-continuous gradient trajectory such as a square trajectory. The design method is based on a novel fractional order proportional integral derivative (FOPID) control strategy, which is proposed to control the movement of UGV to track given trajectories. Two FOPID controllers are required in this design. The first FOPID is constructed in order to control the orientation of UGV. The second FOPID controller is to control the speed of UGV. The particle swarm optimization (PSO) algorithm is used to obtain the optimal parameters for both controllers. The significance of the proposed method is that an observable improvement has been achieved in terms of minimising trajectory-tracking errors and reducing control efforts, especially in continuous gradient trajectories. The stability of the proposed controllers is investigated based upon Nyquist stability criterion. Moreover, the robustness of the controllers is examined in the presence of disturbances to demonstrate the effectiveness of the controllers under certain harsh conditions. The influence from external disturbances has been represented by square pulses and sinusoidal waves. The drawback of this method, however, a highly trajectory tracking error is observed in non-continuous gradient trajectories due to the sharpness of the rotation at the corners of a square trajectory. To overcome this drawback, a new controller, abbreviated as (NN-FOPID), has been proposed based on a combination of neural networks and the FOPID. The purpose is to minimise the trajectory tracking error of non-continuous trajectories, in particular. The Levenberg-Marquardt (LM) algorithm is used to train the NN-FOPID controller. The neural networks' cognitive capacities have made the system adaptable to respond effectively to the variants in trajectories. The obtained results by using NN-FOPID have shown a significant improvement of reducing errors of trajectory tracking and increasing control efforts over the results by FOPID. The other task is to solve the navigation problem of UGV in static and dynamic environments. This can be conducted by firstly constructing workspace environments that contain multiple dynamic and static obstacles. The dynamic obstructing obstacles can move in different velocities. The static obstacles can be randomly positioned in the workspace and all obstacles are allowed to have different sizes and shapes. Secondly, a UGV can be placed in any initial posture on the condition that it has to reach a given destination within the boundaries of the workspace. Thirdly, a method based on fuzzy inference systems (FIS) is proposed to control the motion of the UGV. The design of FIS is based on fuzzification, inference engine and defuzzification processes. The navigation task is divided into obstacle avoidance and target reaching tasks. Consequently, two individual FIS controllers are required to drive the actuators of the UGV, one is to avoid obstacles and the other is to reach a target. Both FIS controllers are combined through a switching mechanism to select the obstacle avoidance FIS controller if there is an obstacle, otherwise choosing reaching target FIS. The simulation results have confirmed the effectiveness of the proposed design in terms of obtaining optimal paths with shortest elapsed time. Similarly, a new method is proposed based on an adaptive neurofuzzy inference system (ANFIS) to guide the UGV in unstructured environments. This method combines the advantages of adaptive leaning and inference fuzzy system. The simulation results have demonstrated adequate achievements in terms of obtaining shortest and feasible paths whilst avoiding static obstructing obstacles and hence reaching the specified targets speedily. Finally, a UGV is constructed to investigate the overall performance of the proposed FIS controllers practically. The architecture of the UGV consists of three ultrasonic sensors, a magnetic compass and two quadratic decoders that they are interfaced with an Arduino microcontroller to read the sensory information. The Arduino, who acts as a slave microcontroller is serially connected with a master Raspberry Pi microcontroller. Raspberry Pi and Arduino communicate with each other based on a proposed hierarchical algorithm. Three case studies are introduced to demonstrate the effectiveness and the validation of the proposed FIS controllers and the UGV's platform in real-time.
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Yu, Ada (Ada Cheuk Ying). "Design for manufacturing analysis on the Small Unmanned Ground Vehicle." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44849.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, 2008.Includes bibliographical references (p. 65).
iRobot is responsible for delivering the Small Unmanned Ground Vehicle (SUGV) as part of the U.S. Army's Future Combat Systems (FCS) initiative. With increasing external competition and pressures, iRobot must deliver an innovative robot while reducing costs, improving quality, and shortening the product's time to market. Since 100% of iRobot's manufacturing is outsourced, the SUGV manufacturing team must optimize its mechanical design in order to help ensure a smooth handoff between its design team and its contract manufacturer. To achieve this goal, the SUGV manufacturing team utilized a Design for Manufacturability and Assembly (DFMA) analysis to simplify components, reduce assembly steps, and improve processes. This paper describes the benefits of DFMA and the tools and techniques used in conducting this analysis. By studying mechanical assemblies, reviewing design drawings with the engineers, and gathering best practices from other industries, this paper provides recommendations for design changes on the SUGV and organizational strategies that can help improve iRobot's product development process.
by Ada Yu.
S.M.
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Persson, Linnea. "Cooperative Control for Landing a Fixed-Wing Unmanned Aerial Vehicle on a Ground Vehicle." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187667.
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High Altitude Long Endurance (HALE) platforms are a type of Unmanned Aerial Vehicle (UAV). With their relatively easy deployment and independence of a fixed orbit, HALE UAVs have the potential to replace satellites for certain tasks in the future. A challenge with this technology is that the current platforms are too heavy to fly for a long period of time. A suggested method for reducing the weight is to remove the landing gear to instead use alternative methods for take-off and landing. One such alternative method is to land the UAV on top of a cooperating ground vehicle. In this thesis, the cooperative controller and the experimental setup of such a landing have been investigated. The cooperation between the systems was analyzed and evaluated analytically, through simulations and with flight tests. Using a PID controller for the position alignment and a modified flare law for the descent, feasibility of the landing was verified by performing a landing of a Penguin BE fixed-wing UAV on top of a cooperating ground vehicle.Så kallade HALE - High Altitude Long Endurance -farkoster är en växande teknik inom området för autonoma flygplan. Med fördelar som exempelvis en möjlighet att röra sig oberoende av en omloppsbana samt en mer effektiv implementering– och utvecklingsprocess har de visat potential att i framtiden kunna ersätta satelliter inom vissa områden. Ett problem är i dagsläget svårigheten att bygga tillräckligt lätta farkoster för att kunna flyga under en längre tidsperiod. För att minska vikten har det bland annat föreslagits att landningsställ kan tas bort för att istället använda alternativa start- och landningsmetoder. I detta projekt har en metod undersökts där idén är att landa ett autonomt flygplan på en mobil plattform. Samarbetet mellan systemen har analyserats både analytiskt och genom tester. Slutligen verifieras att en kooperativ landning är genomförbar genom att en landning av ett obemannat flygplan på en samarbetande bil utförs.
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Beach, Timothy M. "Mobility modeling and estimation for delay tolerant unmanned ground vehicle networks." Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/34624.
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Approved for public release; distribution is unlimitedAn ad hoc unmanned ground vehicle (UGV) network operates as an intermittently connected mobile delay tolerant network (DTN). The path planning strategy in a DTN requires mobility estimation of the spatial positions of the nodes as a function of time. The purpose of this thesis is to create a foundational mobility estimation algorithm that can be coupled with a cooperative communication routing algorithm to provide a basis for real time path planning in UGV-DTNs. In this thesis, we use a Gauss-Markov state space model for the node dynamics. The measurements are constant power received signal strength indicator (RSSI) signals transmitted from fixed position base stations. An extended Kalman filter (EKF) is derived for estimating of coordinates in a two-dimensional spatial grid environment. Simulation studies are conducted to test and validate the models and estimation algorithms. We simulate a single mobile node traveling along a trajectory that includes abrupt maneuvers. Estimation performance is measured using zero mean whiteness tests on the innovations sequences, root mean squared error (RMSE) of the state estimates, weighted sum squared residuals (WSSRs) on the innovations, and the posterior Cramer-Rao lower bound (PCRLB). Under these performance indices, we demonstrate that the mobility estimator performs effectively.
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Hager, Daniel Michael. "Situational Awareness of a Ground Robot From an Unmanned Aerial Vehicle." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32825.
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In the operation of unmanned vehicles, safety is a primary concern. This thesis focuses on the use of computer vision in the development of a situational awareness system that allows for safe deployment and operation of a ground robot from an unmanned aerial vehicle (UAV). A method for detecting utility cables in 3D range images is presented. This technique finds areas of an image that represent edges in 3D space, and uses the Hough transform to find those edges that take the shape of lines, indicating potential utility cables. A mission plan for stereo image capture is laid out as well for overcoming some weaknesses of the stereo vision system; this helps ensure that all utility cables in a scene are detected. In addition, the system partitions the point cloud into best-fit planes and uses these planes to locate areas of the scene that are traversable by a ground robot. Each planeâ s slope is tested against an acceptable value for negotiation by the robot, and the drop-off between the plane and its neighbors is examined as well. With the results of this analysis, the system locates the largest traversable region of the terrain using concepts from graph theory. The system displays this region to the human operator with the drop-offs between planes clearly indicated. The position of the robot is also simulated in this system, and real-time feedback regarding dangerous moves is issued to the operator.
After a ground robot is deployed to the chosen site, the system must be capable of tracking it in real time as well. To this end, a software routine that uses ARToolkitâ s marker tracking capabilities is developed. This application computes the distance to the robot, as well as the horizontal distance from camera to the robot; this allows the flight controller to issue the proper commands to keep the robot centered underneath the UAV.Master of Science
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Pelentrides, Ioannis. "Experimental Sensitivity Analysis of a Network Controlled Unmanned Ground Vehicle in iSpace." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-10302007-113420/.
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The use of a shared network, as a communication channel, in a Networked Control System (NCS) can provide an economical and easily accessible resource. However, it can also result in performance degradation or even destabilization of the control system. Similar effects may arise from different operating conditions of the system. In this research, the effect of the network is compared with the effects exerted by three other parameters in an Unmanned Ground Vehicle (UGV) path-tracking problem. The system?s performance is quantified by means of three characteristics: the deviation error, the system?s runtime and the error-time product. Design of Experiments (DOE) and regression analysis are utilized to appropriately collect and analyze experimental data. For the ranges of variation studied, it is shown that the system is two times more sensitive to the speed of the vehicle than to network?s delay. The effect of the look-ahead distance is shown to be similar to the network?s delay effect, indicating a potential control strategy to alleviate the network?s effect by appropriately adjusting the look-ahead distance. The above results are drawn with respect to the completion time and the error-time product characteristics of the system. The deviation error is shown to have a more complex relationship with the four parameters studied and their effects can only be calculated locally, based on the operating conditions of the system.
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Young, Stuart Harry. "A Model-Based Framework for Predicting Autonomous Unmanned Ground Vehicle System Performance." Thesis, The George Washington University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10124164.
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The past decade has seen the rapid development and deployment of unmanned systems throughout the world in both civilian and military applications. Significant development has been led by the Department of Defense (DoD), which has sought to develop and field military systems, such as unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs), with elevated levels of autonomy to accomplish their mission with reduced funding and manpower. As their role increases, such systems must be able to adapt and learn, and make nondeterministic decisions. Current unmanned systems exhibit minimal autonomous behaviors. As their autonomy increases and their behaviors become more intelligent (adapting and learning from previous experiences), the state space for their behaviors becomes non deterministic or intractably complex.
Consequently, fielding such systems requires extensive testing and evaluation, as well as verification and validation to determine a system’s performance and the acceptable level of risk to make it releasable – a challenging task. To address this, I apply a novel systems perspective to develop a model-based framework to predict future system performance based on the complexity of the operating environment using newly introduced complexity measures and learned costs. Herein I consider an autonomous military ground robot navigating in complex off-road environments. Using my model and data from Defense Advanced Research Projects Agency (DARPA)-led experiments, I demonstrate the accuracy with which my model can predict system performance and then validate my model against other experimental results.
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Yan, Yutong. "Simulation, Control and Path Planning for Articulated Unmanned Ground Vehicles." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-126394.
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The purpose of this project is to implement obstacle avoidance algorithms to drive the articulated vehicle autonomously in an unknown environment, which is simulated by AgX Dynamics™ simulation software and controlled by Matlab® programming software. Three driving modes are developed for driving the vehicle (Manual, Semi-autonomous and Autonomous) in this project. Path tracking algorithms and obstacle avoidance algorithms are implemented to navigate the vehicle. A GUI was built and used for the manual driving mode in this project. The semi-autonomous mode checked different cases: change lanes, U-turn, following a line, following a path and figure 8 course. The autonomous mode is implemented to drive the articulated vehicle in an unknown environment with moving to a pose path tracking algorithm and VFH+ obstacle avoidance algorithm. Thus, the simulation model and VFH+ obstacle avoidance algorithm seems to be working fine and still can be improved for the autonomous vehicle. The result of this project showed a good performance of the simulation model. Moreover, this simulation software helps to minimize the cost of the articulated vehicle since all tests are in the simulation rather than in the reality.
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Tan, Ruoyu. "Tracking of Ground Mobile Targets by Quadrotor Unmanned Aerial Vehicles." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378194694.
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Bayar, Gokhan. "Trajectory Tracking Control Of Unmanned Ground Vehicles In Mixed Terrain." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615105/index.pdf.
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Mobile robots are commonly used to achieve tasks involving tracking a desired trajectory and following a predefined path in different types of terrains that have different surface characteristics. A mobile robot can perform the same navigation task task over different surfaces if the tracking performance and accuracy are not essential. However, if the tracking performance is the main objective, due to changing the characteristics of wheel-ground interaction, a single set of controller parameters or an equation of motion might be easily failing to guarantee a desired performance and accuracy. The interaction occurring between the wheels and ground can be integrated into the system model so that the performance of the mobile robot can be enhanced on various surfaces. This modeling approach related to wheel-ground interaction can also be incorporated into the motion controller. In this thesis study, modeling studies for a two wheeled differential drive mobile robot and a steerable four-wheeled robot vehicle are carried out. A strategy to achieve better tracking performance for a differential drive mobile robot is developed by introducing a procedure including the effects of external wheel forcesi.e, traction, rolling and lateral. A new methodology to represent the effects of lateral wheel force is proposed. An estimation procedure to estimate the parameters of external wheel forces is also introduced. Moreover, a modeling study that is related to show the effects of surface inclination on tracking performance is performed and the system model of the differential drive mobile robot is updated accordingly. In order to accomplish better trajectory tracking performance and accuracy for a steerable four-wheeled mobile robot, a modeling work that includes a desired trajectory generator and trajectory tracking controller is implemented. The slippage is defined via the slip velocities of steerable front and motorized rear wheels of the mobile robot. These slip velocities are obtained by using the proposed slippage estimation procedure. The estimated slippage information is then comprised into the system model so as to increase the performance and accuracy of the trajectory tracking tasks. All the modeling studies proposed in this study are tested by using simulations and verified on experimental platforms.
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Putney, Joseph Satoru. "Reactive Navigation of an Autonomous Ground Vehicle Using Dynamic Expanding Zones." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/33224.
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Autonomous navigation of mobile robots through unstructured terrain presents
many challenges. The task becomes even more difficult with increasing obstacle density,
at higher speeds, and when a priori knowledge of the terrain is not available. Reactive
navigation schemas are often dismissed as overly simplistic or considered to be inferior
to deliberative approaches for off-road navigation. The Potential Field algorithm has
been a popular reactive approach for low speed, highly maneuverable mobile robots.
However, as vehicle speeds increase, Potential Fields becomes less effective at avoiding
obstacles.
The traditional shortcomings of the Potential Field approach can be largely
overcome by using dynamically expanding perception zones to help track objects of
immediate interest. This newly developed technique is hereafter referred to as the
Dynamic Expanding Zones (DEZ) algorithm. In this approach, the Potential Field
algorithm is used for waypoint navigation and the DEZ algorithm is used for obstacle
avoidance. This combination of methods facilitates high-speed navigation in obstaclerich
environments at a fraction of the computational cost and complexity of deliberative
methods.
The DEZ reactive navigation algorithm is believed to represent a fundamental
contribution to the body of knowledge in the area of high-speed reactive navigation.
This method was implemented on the Virginia Tech DARPA Grand Challenge vehicles.
The results of this implementation are presented as a case study to demonstrate the
efficacy of the newly developed DEZ approach.Master of Science
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Muppidi, Shashidhar. "Development of a low cost controller and navigation system for unmanned ground vehicle." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5916.
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Thesis (M.S.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains x, 141 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 76-78).
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Guzman, Cabrera Kelvyn Jose. "Simulation modeling and analysis package for unmanned ground vehicle systems in urban environment." FIU Digital Commons, 2010. https://digitalcommons.fiu.edu/etd/3975.
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The primary purpose of this research was to develop and demonstrate a tool that will help improve the development, testing and implementation of control algorithms as well as the 3D animation of UGVs to virtually evaluate their performance in an urban environment This project describes a functional UGV prototype in a virtual environment. Configuration and assembly of sensors on a real UGV requires skills in many areas which make it difficult for an engineer specialized in one area. In this work, a new approach for the solution of this problem has been developed utilizing the Virtual Environment Software. A pathfinding algorithm is used to work as a GPS system and provide the vehicle with information for the path to follow. The path is recalculated every time the vehicle detects an obstacle on its way. Sonar sensors are also developed virtually to detect obstacles. Performance of a UGV is demonstrated in a realistic urban environment.
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Roa, Christian Raphael. "Smart Power Module for Distributed Sensor Power Network of an Unmanned Ground Vehicle." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64467.
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Energy efficiency is a driving factor in modern electronic design particularly in power conversion where conversion losses directly set the upper limit of system efficiency. A wide variety of commercially available DC-DC conversion elements have inefficiencies in the 90-97% range. The efficiency range of most common commercial-off-the-shelf (COTS) power supplies is 75-85%, highlighting the fact that COTS power supplies have not kept pace with efficiency improvements of modern conversion elements.
Unmanned ground vehicles (UGVs) is an application where efficiency can be crucial in extending tight power budgets. In autonomous ground vehicles, geographic diversity with regard to sensor location is inherent because sensor orientation and placement are crucial to performance. Sensor power, therefore, is also distributed by nature of the devices being supplied.
This thesis presents the design and evaluation of a smart power module used to implement a distributed power network in an autonomous ground vehicle. The module conversion element demonstrated an average efficiency of 96.7% for loads from 1-4A. Current monitoring and an adjustable output current limit were provided through a second circuit board within the same module enclosure. The module processing element sends periodic updates and receives commands over a CAN bus. The smart power modules successfully supply critical sensing and communication components in an operational autonomous ground vehicle.Master of Science
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Curtis, Andrew B. "Path Planning for Unmanned Air and Ground Vehicles in Urban Environments." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2270.pdf.
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Cersovsky, Donald D. Kleinschmidt Edward. "Mathematical model and analysis of the Tactical Unmanned Ground Vehicle (TUGV) using computer simulation /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA272258.
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Mercer, Anthony Scott. "Autonomous unmanned ground vehicle for non-destructive testing of fiber reinforced polymer bridge decks." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4943.
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Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains x, 100 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 83-86).
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Cersovsky, Donald D., and Edward Kleinschmidt. "Mathematical model and analysis of the Tactical Unmanned Ground Vehicle (TUGV) using computer simulation." Thesis, Monterey, California. Naval Postgraduate School, 1993. http://hdl.handle.net/10945/26052.
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The purpose of this thesis is to mathematically model the Tactical Unmanned Ground Vehicle (TUGV) in the Janus(A) Combat Model. The TUGV has three sensors, an optical, thermal, and acoustic sensor. Algorithms currently exist in Janus(A) for both optical and thermal sensors. An acoustic detection algorithm exists although not available to all Janus(A) system users. This thesis examines the TUGV prototype, explains the Janus(A) TUGV model, discusses existing acoustic detection algorithms, and tests the TUGV model in a scenario driven experiment
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Rådman, Marcus. "Implementation and testing of a path tracker for a full-scale Unmanned Ground Vehicle." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73079.
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This project is the implementation and testing of a path tracker for a car-sized Unmanned Ground Vehicle. The vehicle, a Toyota Land Cruiser, was provided by SSC and hadpreviously been modified for remote operation. The developed path tracker uses a "follow the carrot" algorithm and has been writtenin C using the Robot Operating Software (ROS) framework and has been integrated intothe vehicles existing ROS powered software. During the implementation, the Gazebo rigid body simulator was used to simulate a simplified vehicle. Integration with the real sensors was performed using a small-scalecar, both indoors with the aid of a Vicon motion capture system and outdoors utilizingonly sensors available to the full-size car. The small-scale tests showed promise, howeverwhen full-scale field tests were performed the results showed some problems and reasonsfor these are discussed.
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Hacinecipoglu, Akif. "Development Of Electrical And Control System Of An Unmanned Ground Vehicle For Force Feedback Teleoperation." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614807/index.pdf.
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Teleoperation of an unmanned vehicle is a challenging task for human operators especially when the vehicle is out of line of sight. Improperly designed and applied display interfaces directly affect the operation performance negatively and even can result in catastrophic failures. If these teleoperation missions are human-critical then it becomes more important to improve the operator performance by decreasing workload, managing stress and improving situational awareness. This research aims to develop electrical and control system of an unmanned ground vehicle (UGV) using an All-Terrain Vehicle (ATV) and validate the development with investigation of the effects of force feedback devices on the teleoperation performance. After development, teleoperation tests are performed to verify that force feedback generated from the dynamic obstacle information of the environment improves teleoperation performance. Results confirm this statement and the developed UGV is verified for future research studies. Development of UGV, algorithms and real system tests are included in this thesis.
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Colombo, Gian. "The visual search effectiveness of an unmanned ground vehicle operator within an optical flow condition." Honors in the Major Thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1069.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Sciences
Psychology
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Christie, Gordon A. "Collaborative Unmanned Air and Ground Vehicle Perception for Scene Understanding, Planning and GPS-denied Localization." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/83807.
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Autonomous robot missions in unknown environments are challenging. In many cases, the systems involved are unable to use a priori information about the scene (e.g. road maps). This is especially true in disaster response scenarios, where existing maps are now out of date. Areas without GPS are another concern, especially when the involved systems are tasked with navigating a path planned by a remote base station. Scene understanding via robots' perception data (e.g. images) can greatly assist in overcoming these challenges. This dissertation makes three contributions that help overcome these challenges, where there is a focus on the application of autonomously searching for radiation sources with unmanned aerial vehicles (UAV) and unmanned ground vehicles (UGV) in unknown and unstructured environments. The three main contributions of this dissertation are: (1) An approach to overcome the challenges associated with simultaneously trying to understand 2D and 3D information about the environment. (2) Algorithms and experiments involving scene understanding for real-world autonomous search tasks. The experiments involve a UAV and a UGV searching for potentially hazardous sources of radiation is an unknown environment. (3) An approach to the registration of a UGV in areas without GPS using 2D image data and 3D data, where localization is performed in an overhead map generated from imagery captured in the air.Ph. D.
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Schmitz, Austin. "Row crop navigation by autonomous ground vehicle for crop scouting." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/36237.
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Master of ScienceDepartment of Biological & Agricultural Engineering
Daniel Flippo
Robotic vehicles have the potential to play a key role in the future of agriculture. For this to happen designs that are cost effective, robust, and easy to use will be necessary. Robotic vehicles that can pest scout, monitor crop health, and potentially plant and harvest crops will provide new ways to increase production within agriculture. At this time, the use of robotic vehicles to plant and harvest crops poses many challenges including complexity and power consumption. The incorporation of small robotic vehicles for monitoring and scouting fields has the potential to allow for easier integration of robotic systems into current farming practices as the technology continues to develop. Benefits of using unmanned ground vehicles (UGVs) for crop scouting include higher resolution and real time mapping, measuring, and monitoring of pest location density, crop nutrient levels, and soil moisture levels. The focus of this research is the ability of a UGV to scout pest populations and pest patterns to complement existing scouting technology used on UAVs to capture information about nutrient and water levels. There are many challenges to integrating UGVs in conventionally planted fields of row crops including intra-row and inter-row maneuvering. For intra-row maneuvering; i.e. between two rows of corn, cost effective sensors will be needed to keep the UGV between straight rows, to follow contoured rows, and avoid local objects. Inter-row maneuvering involves navigating from long straight rows to the headlands by moving through the space between two plants in a row. Oftentimes headland rows are perpendicular to the row that the UGV is within and if the crop is corn, the spacing between plants can be as narrow as 5”. A vehicle design that minimizes or eliminates crop damage when inter-row maneuvering occurs will be very beneficial and allow for earlier integration of robotic crop scouting into conventional farming practices. Using three fixed HC-SR04 ultrasonic sensors with LabVIEW programming proved to be a cost effective, simple, solution for intra-row maneuvering of an unmanned ground vehicle through a simulated corn row. Inter-row maneuvering was accomplished by designing a transformable tracked vehicle with the two configurations of the tracks being parallel and linear. The robotic vehicle operates with tracks parallel to each other and skid steering being the method of control for traveling between rows of corn. When the robotic vehicle needs to move through narrow spaces or from one row to the next, two motors rotate the frame of the tracks to a linear configuration where one track follows the other track. In the linear configuration the vehicle has a width of 5 inches which allows it to move between corn plants in high population fields for minimally invasive maneuvers. Fleets of robotic vehicles will be required to perform scouting operations on large fields. Some robotic vehicle operations will require coordination between machines to complete the tasks assigned. Simulation of the path planning for coordination of multiple machines was studied within the context of a non-stationary traveling salesman problem to determine optimal path plans.
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Marques, João. "Os Veículos Terrestres Não Tripulados no Campo de Batalha Moderno." Master's thesis, Academia Militar. Direção de Ensino, 2013. http://hdl.handle.net/10400.26/7983.
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Este Trabalho de Investigação Aplicada tem como finalidade estudar quais as
implicações da introdução dos Unmanned Ground Vehicles (UGV), nas pequenas unidades de manobra de escalão Companhia/Esquadrão do Exército Português. Para se alcançar esta finalidade, delimitou-se o estudo desta investigação nas áreas da Organização, Doutrina, Táticas, Técnicas e Procedimentos e Apoio Logístico. Os principais instrumentos de recolha de dados utilizados foram as entrevistas e estudos de caso. As entrevistas foram realizadas a 13 Oficiais e Sargentos do Quadro Permanente das Armas de Infantaria e Cavalaria. As questões das entrevistas incidiram principalmente sobre quais as principais alterações que ocorreriam com a possível introdução dos UGV no Exército Português, em especial nas unidades de escalão Companhia/Esquadrão.
Através da análise dos dados, concluiu-se que as alterações ocorridas a nível da Organização e Doutrina vão depender essencialmente da tipologia do equipamento que se introduzir nas unidades, consequentemente a articulação das unidades aquando do cumprimento de qualquer missão irá ser diferente da articulação normalmente realizada.
Porém, quer as alterações sejam mais ou menos profundas, consoante o equipamento, deve-se proceder a uma revisão dos Quadros Orgânicos das unidades e dos manuais de referência.
A nível de Táticas, Técnicas e Procedimentos, é onde se localizam as alterações mais significativas com a introdução de UGV nas pequenas unidades, independentemente da sua tipologia. As implicações vão ser muito significativas, com maior incidência nas Normas de Execução Permanente (NEP), pois a atuação dos militares perante este equipamento tem de se adaptar radicalmente.
Na dimensão do Apoio Logístico, as principais alterações não vão ocorrer no escalão estudado, mas sim ao nível Batalhão/Grupo. A única exceção que se verifica no escalão Companhia/Esquadrão é nos Esquadrões de Reconhecimento.Abstract This Applied Research Work aims to study the implications of the introduction of Unmanned Ground Vehicles (UGV), in small maneuver units, echelon Company/Troop of the Portuguese Army. To achieve this purpose, the study of this research was delimited to the areas of Organization, Doctrine, Tactics, Techniques and Pr ocedures and Logistics Support. The main instruments used for data collection were interviews and case studies. The interviews were conducted at 13 Officers and Sergeants of the Permanent Staff from Infantry and Cavalry. The interview questions focused in the main changes that might occur with the possible introduction of the UGV in the Portuguese Army, especially in units echelon Company / Troop. Through data analysis, it was concluded that the changes in the level of organization and doctrine will essent ially depend on the type of equipment that is made to the units, although the articulation of the units for the accomplishment of any mission will be different from the usual articulation. However, whether the changes are more or less profound, depending o n the equipment, a review of Organic Frameworks units, and reference manuals must be conducted. The level of Tactics, Techniques and Procedures, is where the most significant changes with the introduction of UGV in small units will occur, regardless of the ir type. The implications will be very significant, with the highest incidence in the Standard Procedures (NEP) since the actions of the military facing this equipment must adapt radically. In the dimension of Logistical Support, major changes will not occ ur in the studied echelon, but in the step above, which is Battalion / Squadron. The only exception occurs in step Company / Troop is the Reconnaissance Troops.
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Deneault, Dustin. "Tracking ground targets with measurements obtained from a single monocular camera mounted on an Unmanned Aerial Vehicle." Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/528.
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Krawiec, Bryan Michael. "A*-Based Path Planning for an Unmanned Aerial and Ground Vehicle Team in a Radio Repeating Operation." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32545.
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In the event of a disaster, first responders must rapidly gain situational awareness about the environment in order to plan effective response operations. Unmanned ground vehicles are well suited for this task but often require a strong communication link to a remote ground station to effectively relay information. When considering an obstacle-rich environment, non-line-of-sight conditions and naive navigation strategies can cause substantial degradations in radio link quality. Therefore, this thesis incorporates an unmanned aerial vehicle as a radio repeating node and presents a path planning strategy to cooperatively navigate the vehicle team so that radio link health is maintained.
This navigation technique is formulated as an A*-based search and this thesis presents the formulation of this path planner as well as an investigation into strategies that provide computational efficiency to the search process. The path planner uses predictions of radio signal health at different vehicle configurations to effectively navigate the vehicles and simulations have shown that the path planner produces favorable results in comparison to several conceivable naive radio repeating variants. The results also show that the radio repeating path planner has outperformed the naive variants in both simulated environments and in field testing where a Yamaha RMAX unmanned helicopter and a ground vehicle were used as the vehicle team.
Since A* is a general search process, this thesis also presents a roadway detection algorithm using A* and edge detection image processing techniques. This algorithm can supplement unmanned vehicle operations and has shown favorable performance for images with well-defined roadways.Master of Science
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Bhattacharyya, Sampriti. "Design and dynamic modeling of an unmanned underwater vehicle for submerged surface inspection exploiting hydrodynamic ground effect." Thesis, Massachusetts Institute of Technology, 2017. https://hdl.handle.net/1721.1/122882.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017Cataloged from PDF version of thesis.
Includes bibliographical references (pages 224-233).
Anticipated growth of sub-sea technologies for security, infrastructure inspection, and exploration, motivates a deeper understanding of underwater navigation in proximity to a submerged target surface. Common examples range from water tanks in nuclear reactors, submerged oil rig infrastructure, to ship hulls with hidden compartments and threats. We propose EVIE (Ellipsoidal Vehicle for Inspection and Exploration): a water jet propelled, football sized ellipsoidal Unmanned Underwater Vehicle (UUV) with a flattened base to house necessary sensors needed for surface inspections. The UUV is designed - both in terms of its shape and propulsion - for gliding on submerged surfaces for volumetric inspection, in addition to motion in free stream motion for visual inspections. This thesis research explores the ground effect hydrodynamics due to the motion of a body near a surface.
We demonstrate the formation of a thin fluid bed layer between the surfaces which enables smooth motion even on rough surfaces. The proposed robot eliminates the need for wheels or suction. Use of ground effect fluid dynamics is common in aerial and land vehicles but is almost unexplored for underwater applications. We focus exploiting this phenomenon in real world applications, developing a prototype model to maintain precise distances with reduced actuator control. We explore both parasitic (induced by lateral motion) and explicitly induced (adding a impinging bottom jet) hydrodynamic effects. We find the force is not only non linear, it is not monotonic and has multiple equilibria. As the body approaches the surface it first experiences repulsion (enhanced thrust) due to an up-wash effect - similar to vertical take off and landing (VTOL) vehicles which can hover at reduced thrust. This transitions to a suction force at small distances from a Venturi effect.
At still smaller distances there is again a repulsion due to choking flow between the body and the surface. Given the complexity of the force, and considering the hydrodynamic drag is non linear as well, traditional linearization fails to capture the system behavior and is at best constrained to a small region around the equilibrium. Instead, we use a higher dimensional, data driven approach for modeling. The underlying hypothesis is that dynamical systems behave linearly when recast in a suitable higher dimensional space. State variables are augmented by adding auxiliary variables that sufficiently inform the nonlinear dynamics of the system. We demonstrate a novel and a powerful method of individual estimation of each of the state dependent non linearities by integrating a state estimator into the augmented system. The estimator only uses measured, original states to estimate the non linear forces.
The method is extremely robust: even though the approximated state transition model has significant inaccuracies, we prove guaranteed convergence of the unobserved states. This doctoral thesis encompasses three unique contribution: design and development of a prototype micro UUV platform for testing surface inspection methods; invention and application of a unique underwater phenomenon to the UUV; and establishing a novel mathematical approach for robust estimation of complex non linear elements using a linearized, high dimensional data driven model. The research presented opens a whole new door of opportunities and provides a new perspective for the design of next generation subsea vehicles and technology.
by Sampriti Bhattacharyya
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Lwabona, David Kababa. "The further research, development and design of a Robotic Unmanned Ground Vehicle Platform for Urban Search Rescue." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/5516.
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Includes abstract.Includes bibliographical references.
This report details the further research, development and design of a Robotic Unmanned Ground Vehicle (UGV) Platform for use in Urban Search And Rescue (USAR). The platform depicted in the figure 0.1 is dubbed Ratel (the Afrikaans name for honey badger) and it is the 5th generation UGV developed in the Robotics and Agents Research Laboratory (RARL) at the University of Cape Town (UCT).
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Parsons, Kevin Kenneth. "Design and Simulation of Passive Thermal Management System for Lithium-ion Battery Packs on an Unmanned Ground Vehicle." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/912.
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The transient thermal response of a 15-cell, 48 volt, lithium-ion battery pack for an unmanned ground vehicle was simulated with ANSYS Fluent. Heat generation rates and specific heat capacity of a single cell were experimentally measured and used as input to the thermal model. A heat generation load was applied to each battery and natural convection film boundary conditions were applied to the exterior of the enclosure. The buoyancy-driven natural convection inside the enclosure was modeled along with the radiation heat transfer between internal components. The maximum temperature of the batteries reached 65.6 °C after 630 seconds of usage at a simulated peak power draw of 3,600 watts or roughly 85 amps. This exceeds the manufacturer's maximum recommended operating temperature of 60 °C. The pack was redesigned to incorporate a passive thermal management system consisting of a composite expanded graphite matrix infiltrated with a phase-changing paraffin wax. The redesigned battery pack was similarly modeled, showing a decrease in the maximum temperature to 50.3 °C after 630 seconds at the same power draw. The proposed passive thermal management system kept the batteries within their recommended operating temperature range.
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Baity, Sean Marshall. "Development of a Next-generation Experimental Robotic Vehicle (NERV) that Supports Intelligent and Autonomous Systems Research." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/36102.
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Recent advances in technology have enabled the development of truly autonomous ground vehicles capable of performing complex navigation tasks. As a result, the demand for practical unmanned ground vehicle (UGV) systems has increased dramatically in recent years. Central to these developments is maturation of emerging mobile robotic intelligent and autonomous capability. While the progress UGV technology has been substantial, there are many challenges that still face unmanned vehicle system developers. Foremost is the improvement of perception hardware and intelligent software that supports the evolution of UGV capability.
The development of a Next-generation Experimentation Robotic Vehicle (NERV) serves to provide a small UGV baseline platform supporting experimentation focused on progression of the state-of-the-art in unmanned systems. Supporting research and user feedback highlight the needs that provide justification for an advanced small UGV research platform. Primarily, such a vehicle must be based upon open and technology independent system architecture while exhibiting improved mobility over relatively structured terrain.
To this end, a theoretical kinematic model is presented for a novel two-body multi degree-of-freedom, four-wheel drive, small UGV platform. The efficacy of the theoretical kinematic model was validated through computer simulation and experimentation on a full-scale proof-of-concept mobile robotic platform. The kinematic model provides the foundation for autonomous multi-body control. Further, a modular system level design based upon the concepts of the Joint Architecture for Unmanned Systems (JAUS) is offered as an open architecture model providing a scalable system integration solution. Together these elements provide a blueprint for the development of a small UGV capable of supporting the needs of a wide range of leading-edge intelligent system research initiatives.Master of Science
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Terwelp, Christopher Rome. "Remote Control of Hydraulic Equipment for Unexploded Ordnance Remediation." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/32306.
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Automation of hydraulic earth moving and construction equipment is of prime economic and social importance in todayâ s marketplace. A human operator can be replaced or augmented with a robotic system when the job is too dull, dirty or dangerous. There are a myriad of applications in both Government and Industry that could benefit from augmenting or replacing an operator of hydraulic equipment with an intelligent robotic system.
A specific important situation is the removal of unexploded ordnance (UXO). The removal of UXO is a troubling environmental problem that plagues people around the world. This document addresses the danger that UXO pose to military groups in applications such as active range clearance and disposal of unexploded or dud munitions. Disposing of these munitions is a difficult problem, which first begins by determining their location. The process can be aided through the use of teleoperated hydraulic equipment, which allows the operator to be located at a safe distance from these munitions. In the past, converting a large piece of hydraulic construction equipment for teleoperated use has been an expensive task. An important result of this research is demonstrating that through readily available commercial products and existing design methodologies, such robotic tasks can be accomplished at relatively low cost and in a timely, reliable fashion.Master of Science
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Berra, Elias Fernando. "Assessing spring phenology of a temperate woodland : a multiscale comparison of ground, unmanned aerial vehicle and Landsat satellite observations." Thesis, University of Newcastle upon Tyne, 2018. http://hdl.handle.net/10443/4131.
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Vegetation phenology is the study of plant natural life cycle stages. Plant phenological events are related to carbon, energy and water cycles within terrestrial ecosystems, operating from local to global scales. As plant phenology events are highly sensitive to climate fluctuations, the timing of these events has been used as an independent indicator of climate change. The monitoring of forest phenology in a cost-effective manner, at a fine spatial scale and over relatively large areas remains a significant challenge. To address this issue, unmanned aerial vehicles (UAVs) appear to be a potential new platform for forest phenology monitoring. The aim of this research is to assess the potential of UAV data to track the temporal dynamics of spring phenology, from the individual tree to woodland scale, and to cross-compare UAV results against ground and satellite observations, in order to better understand characteristics of UAV data and assess potential for use in validation of satellite-derived phenology. A time series of UAV data were acquired in tandem with an intensive ground campaign during the spring season of 2015, over Hanging Leaves Wood, Northumberland, UK. The radiometric quality of the UAV imagery acquired by two consumer-grade cameras was assessed, in terms of the ability to retrieve reflectance and Normalised Difference Vegetation Index (NDVI), and successfully validated against ground (0.84≤R2≥0.96) and Landsat (0.73≤R2≥0.89) measurements, but only NDVI resulted in stable time series. The start (SOS), middle (MOS) and end (EOS) of spring season dates were estimated at an individual tree-level using UAV time series of NDVI and Green Chromatic Coordinate (GCC), with GCC resulting in a clearer and stronger seasonal signal at a tree crown scale. UAV-derived SOS could be predicted more accurately than MOS and EOS, with an accuracy of less than 1 week for deciduous woodland and within 2 weeks for evergreen. The UAV data were used to map phenological events for individual trees across the whole woodland, demonstrating that contrasting canopy phenological events can occur within the extent of a single Landsat pixel. This accounted for the poor relationships found between UAV- and Landsat-derived phenometrics (R2 < 0.45) in this study. An opportunity is now available to track very fine scale land surface changes over contiguous vegetation communities, information which could improve characterization of vegetation phenology at multiple scales.
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Wang, Shiwei. "Motion Control for Intelligent Ground Vehicles Based on the Selection of Paths Using Fuzzy Inference." Digital WPI, 2014. https://digitalcommons.wpi.edu/etd-theses/725.
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In this paper I describe a motion planning technique for intelligent ground vehicles. The technique is an implementation of a path selection algorithm based on fuzzy inference. The approach extends on the motion planning algorithm known as driving with tentacles. The selection of the tentacle (a drivable path) to follow relies on the calculation of a weighted cost function for each tentacle in the current speed set, and depends on variables such as the distance to the desired position, speed, and the closeness of a tentacle to any obstacles. A Matlab simulation and the practical implementation of the fuzzy inference rule on a Clearpath Husky robot within the Robot Operating System (ROS) framework are provided.
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Tarcin, Serkan. "Fast Feature Extraction From 3d Point Cloud." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615659/index.pdf.
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To teleoperate an unmanned vehicle a rich set of information should be gathered from surroundings.These systems use sensors which sends high amounts of data and processing the data in CPUs can be time consuming. Similarly, the algorithms that use the data may work slow because of the amount of the data. The solution is, preprocessing the data taken from the sensors on the vehicle and transmitting only the necessary parts or the results of the preprocessing. In this thesis a 180 degree laser scanner at the front end of an unmanned ground vehicle (UGV) tilted up and down on a horizontal axis and point clouds constructed from the surroundings. Instead of transmitting this data directly to the path planning or obstacle avoidance algorithms, a preprocessing stage has been run. In this preprocess rst, the points belonging to the ground plane have been detected and a simplied version of ground has been constructed then the obstacles have been detected. At last, a simplied ground plane as ground and simple primitive geometric shapes as obstacles have been sent to the path planning algorithms instead of sending the whole point cloud.
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Lindefelt, Anna, and Anders Nordlund. "A Path Following Method with Obstacle Avoidance for UGVs." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11242.
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The goal of this thesis is to make an unmanned ground vehicle (UGV) follow a given reference trajectory, without colliding with obstacles in its way. This thesis will especially focus on modeling and controlling the UGV, which is based on the power wheelchair Trax from Permobil.
In order to make the UGV follow a given reference trajectory without colliding, it is crucial to know the position of the UGV at all times. Odometry is used to estimate the position of the UGV relative a starting point. For the odometry to work in a satisfying way, parameters such as wheel radii and wheel base have to be calibrated. Two control signals are used to control the motion of the UGV, one to control the speed and one to control the steering angles of the two front wheels. By modeling the motion of the UGV as a function of the control signals, the motion can be predicted. A path following algorithm is developed in order to make the UGV navigate by maps. The maps are given in advance and do not contain any obstacles. A method to handle obstacles that comes in the way is presented.
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Gonzalez, Castro Luis Nicolas. "Coherent design of uninhabited aerial vehicle operations and control stations." Thesis, Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-05182006-172951/.
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Murphy, Taylor Byers. "Apprehending Remote Affordances: Assessing Human Sensor Systems and Their Ability to Understand a Distant Environment." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374144285.
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Kilitci, Serkan, and Muzaffer Buyruk. "An analysis of the best available unmanned ground vehicle in the current market with respect to the requirements of the Turkish Ministry of National Defense." Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/10633.
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MBA Professional ReportToday, Unmanned Ground Vehicles (UGVs) provide significant supporting capabilities in military operations worldwide. When UGVs are used to their full potential, the number of casualties is decreased and the combat effectiveness of warfighters is increased. UGVs are being developed in different sizes to meet different mission capability requirements. The employment of available UGVs and the development of new UGV capabilities have been rising steadily. Countries have started giving more importance to UGVs, and they are now being employed all over the world. The Turkish Ministry of National Defense (MND) can use the advantages of UGVs in a number of ways to assist in its efforts against terrorist activities. The purpose of this MBA project is to conduct an analysis of the best available UGV in the current market with respect to the requirements of the Turkish MND. After providing some background and market research on UGVs, we will explore their capabilities and their capability gaps in regard to the requirements of the Turkish MND. In the end, this project will determine the best available near-term UGV for the Turkish MND by employing the Analysis of Alternatives (AoA) method of the U.S. Defense Acquisition System.
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Sun, Jisang. "Human Interfaces for Cooperative Control of Multiple Vehicle Systems." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1230.pdf.
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Kirchhoff, Allan Richard. "Text Localization for Unmanned Ground Vehicles." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/52569.
Full textAbstract:
Unmanned ground vehicles (UGVs) are increasingly being used for civilian and military
applications. Passive sensing, such as visible cameras, are being used for navigation and object
detection. An additional object of interest in many environments is text. Text information can
supplement the autonomy of unmanned ground vehicles. Text most often appears in the
environment in the form of road signs and storefront signs. Road hazard information, unmapped
route detours and traffic information are available to human drivers through road signs. Premade
road maps lack these traffic details, but with text localization the vehicle could fill the
information gaps. Leading text localization algorithms achieve ~60% accuracy; however,
practical applications are cited to require at least 80% accuracy [49].
The goal of this thesis is to test existing text localization algorithms against challenging scenes,
identify the best candidate and optimize it for scenes a UGV would encounter. Promising text
localization methods were tested against a custom dataset created to best represent scenes a UGV
would encounter. The dataset includes road signs and storefront signs against complex
background. The methods tested were adaptive thresholding, the stroke filter and the stroke
width transform. A temporal tracking proof of concept was also tested. It tracked text through a
series of frames in order to reduce false positives.
Best results were obtained using the stroke width transform with temporal tracking which
achieved an accuracy of 79%. That level of performance approaches requirements for use in
practical applications. Without temporal tracking the stroke width transform yielded an accuracy
of 46%. The runtime was 8.9 seconds per image, which is 44.5 times slower than necessary for
real-time object tracking. Converting the MATLAB code to C++ and running the text
localization on a GPU could provide the necessary speedupMaster of Science
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Ptáček, Ondřej. "Zpracování snímků pořízených pomocí UAV." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-227111.
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This diploma thesis deals with the processing and evaluation of the pictures taken by unmanned aerial vehicles - UAV. The introductory part is devoted to the definition, use, applications and types of UAV especially for photogrammetric purposes. Also the software equipment is described, including a description and examples of several types of possible outcomes. Further the measurements, computational works and process of elaboration in used software programs are described. Achieved outcomes of elaboration are also presented. In conclusion, the overall evaluation and assessment of the results of measurement is done of set of points.
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Rodriguez, Uriel. "Miniaturization of ground station for unmanned air vehicles." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008480.
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Umansky, Mark. "A Prototype Polarimetric Camera for Unmanned Ground Vehicles." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23724.
Full textAbstract:
Unmanned ground vehicles are increasingly employing a combination of active sensors such as LIDAR with passive sensors like cameras to perform at all levels of perception, which includes detection, recognition and classification. Typical cameras measure the intensity of light at a variety of different wavelengths to classify objects in different areas of an image. A polarimetric camera not only measures intensity of light, but can also determine its state of polarization.
The polarization of light is the angle the electric field of the wave of light takes as it travels. A polarimetric camera can identify the state of polarization of the light, which can be used to segment highly polarizing areas in a natural environment, such the surface of water. The polarimetric camera designed and built for this thesis was created with low cost in mind, as commercial polarimetric cameras are very expensive. It uses multiple beam splitters to split incoming light into four machine vision cameras. In front of each machine vision camera is a linear polarizing filter that is set to a specific orientation. Using the data from each camera, the Stokes vector can be calculated on a pixel by pixel basis to determine what areas of the image are more polarized. Test images of various scenes that included running water, standing water, mud, and vehicles showed promise in using polarization data to highlight and identify areas of interest. This data could be used by a UGV to make more informed decisions in an autonomous navigation mode.Master of Science
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Olsson, Martin. "Obstacle detection using stereo vision for unmanned ground vehicles." Thesis, Linköping University, Department of Science and Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-18255.
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