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1
Iagnemma, Karl Dubowsky S. "Mobile robots in rough terrain : estimation, motion planning, and control with application to planetary rovers /." Berlin ; New York : Springer, 2004. http://www.loc.gov/catdir/toc/fy0606/2004106986.html.
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Caurin, Glauco Augusto de Paula. "Control of walking robots on natural terrain /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10898.
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FAHMI, AHMED MOHAMED SHAMEL BAHAAELDEEN. "On Terrain-Aware Locomotion for Legged Robots." Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1045132.
Full textAbstract:
Legged robots are advancing towards being fully autonomous as can be seen
by the recent developments in academia and industry. To accomplish breakthroughs in dynamic whole-body locomotion, and to be robust while traversing
unexplored complex environments, legged robots have to be terrain aware.
Terrain-Aware Locomotion (TAL) implies that the robot can perceive the
terrain with its sensors, and can take decisions based on this information. The
decisions can either be in planning, control, or in state estimation, and the
terrain may vary in geometry or in its physical properties. TAL can be categorized into Proprioceptive Terrain-Aware Locomotion (PTAL), which relies
on the internal robot measurements to negotiate the terrain, and Exteroceptive
Terrain-Aware Locomotion (ETAL) that relies on the robot’s vision to perceive
the terrain. This thesis presents TAL strategies both from a proprioceptive and
an exteroceptive perspective. The strategies are implemented at the level of
locomotion planning, control, and state estimation, and are using optimization
and learning techniques.
The first part of this thesis focuses on PTAL strategies that help the robot
adapt to the terrain geometry and properties. At the Whole-Body Control
(WBC) level, achieving dynamic TAL requires reasoning about the robot dynamics, actuation and kinematic limits as well as the terrain interaction. For
that, we introduce a Passive Whole-Body Control (pWBC) framework that allows the robot to stabilize and walk over challenging terrain while taking into
account the terrain geometry (inclination) and friction properties. The pWBC
relies on rigid contact assumptions which makes it suitable only for stiff terrain. As a consequence, we introduce Soft Terrain Adaptation aNd Compliance
Estimation (STANCE) which is a soft terrain adaptation algorithm that generalizes beyond rigid terrain. STANCE consists of a Compliant Contact Consistent
Whole-Body Control (c3WBC) that adapts the locomotion strategies based on
the terrain impedance, and an online Terrain Compliance Estimator (TCE) that
senses and learns the terrain impedance properties to provide it to the c
3WBC.
Additionally, we demonstrate the effects of terrains with different impedances
on state estimation for legged robots.
The second part of the thesis focuses on ETAL strategies that makes the
robot aware of the terrain geometry using visual (exteroceptive) information.
To do so, we present Vision-Based Terrain-Aware Locomotion (ViTAL) which is
a locomotion planning strategy. ViTAL consists of a Vision-Based Pose Adaptation (VPA) algorithm to plan the robot’s body pose, and a Vision-Based
Foothold Adaptation (VFA) algorithm to select the robot’s footholds. The VFA
is an extension to the state of the art in foothold selection planning strategies. Most importantly, the VPA algorithm introduces a different paradigm for
vision-based pose adaptation. ViTAL relies on a set of robot skills that characterizes the capabilities of the robot and its legs. These skills are then learned
via self-supervised learning using Convolutional Neural Networks (CNNs). The
skills include (but are not limited to) the robot’s ability to assess the terrain’s
geometry, avoid leg collisions, and to avoid reaching kinematic limits. As a
result, we contribute with an online vision-based locomotion planning strategy
that selects the footholds based on the robot capabilities, and the robot pose
that maximizes the chances of the robot succeeding in reaching these footholds.
Our strategies are extensively validated on the quadruped robots HyQ and
HyQReal in simulation and experiment. We show that with the help of these
strategies, we can push dynamic legged robots one step closer towards being
fully autonomous and terrain aware.
4
Häselich, Marcel [Verfasser]. "Markov random field terrain classification for autonomous robots in unstructured terrain / Marcel Häselich." Koblenz : Universitätsbibliothek Koblenz, 2015. http://d-nb.info/1064986544/34.
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5
Guedes, Magno Edgar da Silva. "Vision based obstacle detection for all-terrain robots." Master's thesis, FCT - UNL, 2009. http://hdl.handle.net/10362/3650.
Full textAbstract:
Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em
Engenharia Electrotécnica e de ComputadoresThis dissertation presents a solution to the problem of obstacle detection in all-terrain environments,with particular interest for mobile robots equipped with a stereo vision sensor. Despite the advantages of vision, over other kind of sensors, such as low cost, light weight and reduced energetic footprint, its usage still presents a series of challenges. These include the difficulty in dealing with the considerable amount of generated data, and the robustness required to manage high levels of noise. Such problems can be diminished by making hard assumptions, like considering that the terrain in front of the robot is planar. Although computation can be considerably saved, such simplifications are not necessarily acceptable in more complex environments, where the terrain may be considerably uneven. This dissertation proposes to extend a well known obstacle detector that relaxes the aforementioned planar terrain assumption, thus rendering it more adequate for unstructured environments. The proposed extensions involve: (1) the introduction of a visual saliency mechanism to focus the detection in regions most likely to contain obstacles; (2) voting filters to diminish sensibility to noise; and (3) the fusion of the detector with a complementary method to create a hybrid solution, and thus, more robust. Experimental results obtained with demanding all-terrain images show that, with the proposed extensions, an increment in terms of robustness and computational efficiency over the original algorithm is observed
6
Alves, Nelson Miguel Rosa. "Vision based trail detection for all-terrain robots." Master's thesis, Faculdade de Ciências e Tecnologia, 2010. http://hdl.handle.net/10362/5015.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresEsta dissertação propõe um modelo para detecção de trilhos baseado na observação de que estes são estruturas salientes no campo visual do robô. Devido à complexidade dos ambientes naturais, uma aplicação directa dos modelos tradicionais de saliência visual não é suficientemente robusta para prever a localização dos trilhos. Tal como noutras tarefas de detecção, a robustez pode ser aumentada através da modulação da computação da saliência com conhecimento implícito acerca das características visuais (e.g. cor) que permitem uma melhor representação do objecto a encontrar. Esta dissertação propõe o uso da estrutura global do objecto, sendo esta uma característica mais estável e previsível para o caso de trilhos naturais. Esta nova componente de conhecimento implícito é especificada em termos de regras de percepção activa, que controlam o comportamento de agentes simples que se comportam em conjunto para computar o mapa de saliência da imagem de entrada. Para o propósito de acumulação de informação histórica acerca da localização do trilho é utilizado um campo neuronal dinâmico com compensação de movimento. Resultados experimentais num conjunto de dados vasto revelam a habilidade do modelo de produzir uma taxa de sucesso de 91% a 20Hz. O modelo demonstra ser robusto em situações onde outros detectores falhariam, tal como quando o trilho não emerge da parte de baixo da imagem, ou quando se encontra consideravelmente interrompido.
7
Elanjimattathil, Vijayan Aravind. "Dynamic Locomotion of Quadrupedal Robots over Rough Terrain." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-240409.
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Previous works have enabled locomotion of quadrupedal robots usingthe ZMP-based motion optimization framework on flat terrain withvarious gait patterns. Locomotion over rough terrain brings in newchallenges such as planning safe footholds for the robot, ensuring kinematicstability during locomotion and avoiding foot slippage over roughterrain etc. In this work, terrain perception is integrated into the ZMPbasedmotion optimization framework to enable robots to perform dynamiclocomotion over rough terrain.In a first step, we extend the foothold optimization framework touse processed terrain information to avoid planning unsafe footholdpositions while traversing over rugged terrain. Further, to avoid kinematicviolations during locomotion over rugged terrain, we presentadditional constraints to the ZMP-based motion optimization frameworkto solve for kinematically feasible motion plans in real-time. Weadd nonlinear kinematic constraints to existing nonlinear ZMP motionoptimization framework and solve a Sequential Quadratic Programming(SQP) problem to obtain feasible motion plans. Lastly, to avoidfoot contact slippage, we drop the approximated terrain normal anduse measured terrain normal at foot contact position to compute thefriction polygon constraints.The proposed algorithms are tested in simulation and on hardwarewith dynamic gaits to validate the effectiveness of this approach toenable quadrupedal robots to traverse rugged terrain safely. The computationaltime and performance of the proposed algorithms were analyzedunder various scenarios and presented as part of this thesis.Tidigare forskning har gjort det möjligt att fyrfotade robotar kan rö- ra sig med hjälp av det ZMP-baserade rörelseoptimeringsramverket på platt terräng med olika gångartsmönster. Nya utmaningar före- kommer med förflyttning över grov terräng såsom planering av säk- ra fotfäste för roboten, säkerställning av kinematiskt stabilitet under rörelse, undvikande av fotglidning på grov terräng, och så vidare. I det här verket är terränguppfattning integrerad i det ZMP-baserade rörelseoptimeringsverket så att robotar kan utföra dynamisk rörelse över grov terräng. I första steget utökar vi fotfästeoptimeringsram- verket för att använda bearbetad information om terrängen med syf- tet att undvika planeringen av osäkra fotfästeplaceringar under för- flyttning över grov terräng. För att undvika kinematiska överträdel- ser under förflyttning över grov terräng introducerar vi ytterligare begränsningar till det ZMP-baserade rörelseoptimeringsramverket för att lösa ut kinematiskt rimliga rörelseplaner i realtid. Vi introducerar icke-linjära kinematiska begränsningar till det existerande icke-linjära ZMP-baserade rörelseoptimeringsramverket och löser ett sekventiellt kvadratiskt programmeringsproblem (SQP problem) för att få rimli- ga rörelseplaner. Med syftet att undvika fotkontaktglidning släpper vi den approximerade terrängnormalen och använder den mätta ter- rängnormalen vid fotkontaktläge för att beräkna friktionspolygonbe- gränsningarna. De föreslagna algoritmerna testas i simulering samt på hårdvara med dynamiska gångarter för att bekräfta denna metods ef- fektivitet att tillåta fyrfotade robotar att flytta sig över grov terräng på ett säkert sätt. Algoritmernas beräkningsperiod och prestanda analy- serades i olika fall och redovisades som en del av detta examensarbete.
8
Vijaykumar, R. "Motion planning for legged locomotion systems on uneven terrain /." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487335992904418.
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Weiss, Christian. "Self-Localization and terrain classification for mobile outdoor robots /." München : Verl. Dr. Hut, 2009. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=017311174&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Ward, Christopher Charles. "Terrain sensing and estimation for dynamic outdoor mobile robots." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42419.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (p. 120-125).
In many applications, mobile robots are required to travel on outdoor terrain at high speed. Compared to traditional low-speed, laboratory-based robots, outdoor scenarios pose increased perception and mobility challenges which must be considered to achieve high performance. Additionally, high-speed driving produces dynamic robot-terrain interactions which are normally negligible in low speed driving. This thesis presents algorithms for estimating wheel slip and detecting robot immobilization on outdoor terrain, and for estimating traversed terrain profile and classifying terrain type. Both sets of algorithms utilize common onboard sensors. Two methods are presented for robot immobilization detection. The first method utilizes a dynamic vehicle model to estimate robot velocity and explicitly estimate longitudinal wheel slip. The vehicle model utilizes a novel simplified tire traction/braking force model in addition to estimating external resistive disturbance forces acting on the robot. The dynamic model is combined with sensor measurements in an extended Kalman filter framework. A preliminary algorithm for adapting the tire model parameters is presented. The second, model-free method takes a signal recognition-based approach to analyze inertial measurements to detect robot immobilization. Both approaches are experimentally validated on a robotic platform traveling on a variety of outdoor terrains. Two detector fusion techniques are proposed and experimentally validated which combine multiple detectors to increase detection speed and accuracy. An algorithm is presented to classify outdoor terrain for high-speed mobile robots using a suspension mounted accelerometer. The algorithm utilizes a dynamic vehicle model to estimate the terrain profile and classifies the terrain based on spatial frequency components of the estimated profile. The classification algorithm is validated using experimental results collected with a commercial automobile driving in real-world conditions.
by Christopher Charles Ward.
S.M.
11
Kang, Shinwoo 1976. "Terrain parameter estimation and traversability assessment for mobile robots." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/42830.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.Includes bibliographical references (leaves 65-68).
The estimation of terrain characteristics is an important missions of Martian exploration rovers. Since only limited resources and human supervision are available, efficient and autonomous method of estimation are required. In this thesis, an on-line estimation method of two important terrain parameters, cohesion and internal friction angle, is developed. The method uses onboard rover sensors and is computationally efficient. Terrain parameter estimation is of scientific interest, and can also be useful in predicting rover mobility on rough-terrain. A method to estimate traversability of a rover on deformable terrain using on-board sensors is presented. Simulation and experimental results show that the proposed methods can accurately and efficiently estimate traversability of deformable terrain.
by Shinwoo Kang.
S.M.
12
Emmanuel, Thierry. "Planification robuste et navigation de robots mobiles tout terrain." Montpellier 2, 1995. http://www.theses.fr/1995MON20136.
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Ce memoire de these traite de la planification robuste et adaptative des deplacements de plusieurs robots mobiles sur terrain inegal et evolutif. L'objectif est de fournir au systeme de navigation un ensemble d'itineraires et de consignes de commande (vitesse et cap), autorisant la modification rapide du plan en cas de variations imprevues et importantes des parametres du vehicule ou du terrain. Tout d'abord, les voies de deplacement possible sont issues d'une combinaison de plusieurs types discretises de modelisations du terrain (mnt, courbes de niveau, triangulation), a laquelle on associe un graphe des changements d'etats. Les consignes de vitesse et de cap sont calculees en tenant compte de caracteristiques du relief, des vehicules (contraintes dynamiques, de glissement, de patinage des roues, de renversement et de l'interaction roue/sol), et du critere de performance que l'on considere pour les deplacements. Ensuite nous mettons en uvre des algorithmes de recherche dans le graphe value (par les caracteristiques du vehicule et du relief) afin de determiner des chemins de couts voisins et proches de l'optimal. Les chemins ainsi determines forment un sous-graphe de deplacement pour les robots. Une etude systematique de la vulnerabilite du reseau permet de valider la robustesse de l'execution de la mission. De plus, d'autres etudes sur le sous-graphe de chemins (itineraires) permettent de regrouper ces chemins en familles selon des criteres secondaires ; ceci facilite la reactivite du systeme de commande et donc le bon deroulement du plan de la mission. Des strategies d'execution et de reaction sont mises en uvre pour resoudre les conflits possibles entre les robots. Des resultats sur site reel et de simulation, utilisant comme critere la minimisation de la consommation d'energie d'un vehicule electrique, demontrent les qualites des algorithmes developpes
13
ANDRADE, BARROSO GUILLERMO ENRIQUE. "Modelisation et adaptation du mouvement de robots tout-terrain." Paris 6, 2000. http://www.theses.fr/2000PA066013.
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L'objectif du travail de recherche presente dans ce memoire est la modelisation de la locomotion des vehicules en vue de definir de nouvelles architectures mecaniques et des commandes adaptees a la conduite tout-terrain. Nous nous interessons aux vehicules se deplacant sur un terrain naturel et dans le cadre de l'exploration planetaire. Cependant, les resultats qui sont etablis sont transposables a d'autres types de vehicules tout-terrain. Cette recherche utilise un robot mobile poly-articule de type marsokhod et un terrain naturel. Ce robot possede six roues rigides motorisees sur trois essieux articules et des articulations actives lui permettant d'effectuer des mouvements de reptation appeles mouvements peristaltiques. Nous presentons un simulateur utilisant un modele numerique permettant de reproduire des phenomenes d'ecoulement et d'avalanche qui modifient la forme du terrain. Nous analysons le frottement et les deformations volumiques qui resultent du deplacement des surfaces actives du robot et du sol. Nous introduisons une nouvelle presentation du modele dynamique du robot qui permet le traitement optimise des structures complexes comprenant un grand nombre de chaines cinematiques fermees. L'integration de cette methode au simulateur de terrain permet de disposer d'un outil numerique puissant d'evaluation de maquettes virtuelles de robots tout-terrain. Nous etablissons une methode simple de mesure in situ des parametres de cette interaction robot-sol qui pourront etre utilises dans une commande bas niveau optimisant la traction du vehicule. Nous accorderons une importance particuliere au controle bas niveau permettant une meilleure maitrise de la traction du robot ainsi qu'a l'identification des conditions de passage entre les differents modes de locomotion de ce robot. Les differents points de ce travail ont ete valides par des experimentations. Pour conclure nous faisons le tour des nouvelles perspectives ouvertes par nos travaux.
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Pannu, Rabindra. "Path Traversal Around Obstacles by a Robot using Terrain Marks for Guidance." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1312571550.
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Thüer, Thomas. "Mobility evaluation of wheeled all-terrain robots : metrics and application /." Zürich : ETH, 2009. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18160.
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Kirmizigul, Ugur. "Design Of A Mobile Robot To Move On Rough Terrain." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606814/index.pdf.
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In this thesis work, a mobile robot is designed to be used in search and rescue
operations to help the human rescue workers. The difficult physical conditions in the
ruins obstruct the movement. Therefore, it is aimed to design a search and rescue robot
which can move easily on rough terrain and climb over the obstacles. The designed
robot is made up of three modules. A connecting unit is designed that is situated
between each module. This connecting unit which is composed of two universal
and one revolute joint gives 5 DOF relative motions to the modules. On the other
hand, the wheel&rsquos continuous contact with the ground is important while moving on rough terrain. In order to increase the adaptation of the robot to the rough terrain the rear axle is connected to the body with a revolute joint. Besides, skid steering system is used in the design of the robot to attain a compact and light solution which requires few parts. In the study, kinematic equations and dynamic equations of the robot are obtained to be used by the control program. The dynamic equations are obtained by using the Newton &ndash
Euler formulation. The forces, which are transmitted by the connecting unit to the modules, and the reaction forces formed between the wheels and the ground are derived by using these equations. &ldquo
Follow-the-Leader approach&rdquo
is used as a control strategy to make the modules move in formation and to reduce the tracking problem. In this approach, the first module is the leader and the second and third modules follow it. A Matlab program is written to control the robot by using the constructed mathematical model of the robot. The reaction forces between the wheels and the ground are calculated through using the Matlab program written. Moreover to make the simulations of the robot for some cases, a model is constructed in ADAMS program.
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Chung, Tae-Sang. "Force and compliance control for rough-terrain locomotion by multi-legged robot vehicles /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487262825077357.
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Stelzer, Annett [Verfasser], and Wolfram [Akademischer Betreuer] Burgard. "Approaches to efficient visual homing of mobile robots in rough terrain." Freiburg : Universität, 2016. http://d-nb.info/1124004769/34.
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Tennakoon, Kulatunga Mudiyanselage Eranda Bandara. "Probe-before-step gait framework for multi-legged robot locomotion over terrains with risk of collapse." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/209311/1/Kulatunga%20Mudiyanselage%20Eranda%20Bandara_Tennakoon_Thesis.pdf.
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In many risky tasks such as search and rescue, it is often safer and cost-effective to send robots in place of humans. Multi-legged robots are good at traversing rough terrain, but handling terrain deformations is still a challenge. This thesis proposes a framework allowing multi-legged robots to safely probe the terrain using their legs and test it for subsidence before walking. Two new robot motion control algorithms were introduced that enabled the subsequent development and implementation of two new crawling gaits for hexapod robots. Thanks to this method, the robot can walk safely on dangerous, locally collapsible terrain.
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Kul, Mustafa Cihangir. "Design, Development And Manufacturing Of An All Terrain Modular Robot Platform." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611858/index.pdf.
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The aim of this thesis is to create a flexible multi-purpose modular all terrain robot
platform, which has the potential to be used in commercial applications as well as in
education and research. In developing this robot platform, it is aimed to use readily
available commercial products as much as possible in order to keep the cost of the
product low, increase maintainability, and benefit from the improvements made to
these components in time. The modularity is attained by designing a two wheeled
base module which is autonomous on its own. This base module is composed of
two wheels where, the motors located inside these wheels. It is shown that the
proposed base module facilitates the configuration of various robots to suit the
needs of diverse applications. Detailed design and manufacturing of one of various
possible configurations is presented. Performance tests are conducted on this robot
configuration and effectiveness of the proposed modular approach is justified.
21
Huskić, Goran [Verfasser]. "Control of Outdoor Robots at Higher Speeds on Challenging Terrain / Goran Huskić." München : Verlag Dr. Hut, 2018. http://d-nb.info/1172582076/34.
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Michaluk, Nathaniel. "Design methods for cost-effective teams of mobile robots in uncertain terrain." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92068.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 59-62).
Conducting planetary exploration missions with mobile robots is expensive, with costs ranging from hundreds of millions to billions of dollars. Developing reliable robots to work remotely on rough, uncertain terrain is imperative for these missions. One potential tactic for improving the cost-effectiveness of these missions is to distribute the mass allowance for the mission over a team of smaller robots, rather than using a single robot. However, there is limited work on determining the size and design for a team of robots to provide the best overall performance when operating on hazardous terrain. This thesis develops a framework for designing mass-restricted, homogenous teams of mobile robots that will operate in a region with uncertain terrain conditions. The framework is built around three models: a four-wheeled robot model, a probabilistic model of terrain hazards, and a robot-terrain interaction model. The models are formulated into an optimization problem that can be used to determine the best design for a team of robots based on the team's combined equivalent straight-line velocity (CESLV), a novel measure of mission performance. CESLV is an effective measure of mission performance for both predetermined (static) mission plans and dynamic mission plans, where observations made by the robots can change the future mission tasks. A graphical user interface (GUI) is also presented which allows a designer to explore the design tradespace for the team of robots while considering important factors that are not captured by the models. In a case study of a Mars exploration mission, a team of robots provides superior performance to a single robot. A sensitivity analysis shows that the optimal size of the robot team is robust to inaccuracy in the terrain conditions. Additionally, the tradespace UI captures a trend in robot team design that would have otherwise gone unnoticed.
by Nathaniel Steven Michaluk.
S.M.
23
Golda, Dariusz 1979. "Modeling and analysis of high-speed mobile robots operating on rough terrain." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89384.
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Rocheleau, Simon-Guy. "Petit robot marcheur : plateforme tout-terrain (PROMPT)." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/26968/26968.pdf.
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Khan, Yasir Niaz [Verfasser], and Andreas [Akademischer Betreuer] Zell. "Visual Terrain Classification for Outdoor Mobile Robots / Yasir Niaz Khan ; Betreuer: Andreas Zell." Tübingen : Universitätsbibliothek Tübingen, 2013. http://d-nb.info/1162844027/34.
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Rzepniewski, Adam K. (Adam Kamil) 1976. "Motion planning for high-speed and kinematically reconfigurable mobile robots in rough terrain." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/89330.
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Manaoui, Francis Olivier. "Étude et simulation d'algorithmes de navigation pour robots mobiles autonomes sur terrain inégal." Montpellier 2, 1988. http://www.theses.fr/1988MON20242.
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Le travail de recherche a pour objectif de definir et simuler le fonctionnement d'un navigateur pour robots mobiles autonomes sur sol irregulier. Une analyse bibliographique met en evidence les grands principes de la navigation. Les problemes specifiques des robots evoluant en exterieur sont formalises. On propose alors une modelisation du terrain basee sur la polygonation des courbes de niveaux. Dans l'espace de recherche associe on definit un algorithme de recherche des deplacements elementaires. On propose ensuite une methode de determination du temps de parcours minimal, en fonction des caracteristiques du vehicule, de la geometrie et de la nature du terrain. Enfin on expose les resultats des simulations et une evaluation de la complexite des algorithmes
28
Manaoui, Francis Olivier. "Etude et simulation d'algorithmes de navigation pour robots mobiles autonomes sur terrain inégal." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37615664p.
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Schalit, Emmanuel. "Navigation autonome d'un robot mobile en terrain accidenté." Toulouse 3, 1994. http://www.theses.fr/1994TOU30191.
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Ce memoire presente une approche originale dans le domaine de la navigation autonome en terrain accidente. Il a pour but d'aborder certaines des difficultes rencontrees par cette branche de la robotique. Nos travaux reposent sur des algorithmes simple et rapides, qui operent sur des cartes robocentriques construites a partir de perceptions des capteurs embarques. Les niveaux inferieurs de notre architecture ne modelisent que tres grossierement l'environnement, mais reposent sur une frequence elevee du cycle de perception-planification pour obtenir de reelles capacites de navigation. Ces niveaux ont ete concus pour etre robustes vis-a-vis des erreurs de perception et de la nature discontinue de la perception de l'environnement. Ils prennent egalement en compte le fait que le robot ne decouvre son environnement qu'au fur et a mesure de ses deplacements. Nos concepts ont ete implementes dans le cadre d'une simulation detaillee du deplacement du robot, de ses capteurs et de son environnement. Apres une presentation de l'etat de l'art dans le domaine, nous introduisons les principes fondateurs de notre approche. Puis, nous presentons une analyse theorique de la navigation en terrain accidente, suivie d'un expose des principes algorithmiques de notre systeme de navigation. Enfin, les resultats obtenus a l'aide de l'environnement de simulation arcane que nous avons developpe sont presentes dans le dernier chapitre
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Martin, Steven C. "Proprioceptive sensing of traversability for long-term navigation of robots." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/117074/1/Steven_Martin_Thesis.pdf.
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Mobile robots performing repetitive tasks are often required to expend the bulk of the robot's available energy on mobility. This thesis examines how mobile robot navigation can be optimised when performing repeated long-term tasks in environments with unknown spatial-varying driving characteristics. This work develops techniques that allow mobile robots to sense terrain, estimate traversability using proprioceptive sensors and build maps that enable planning of minimum energy tours.
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Valenzuela, Andrés Klee. "Mixed-integer convex optimization for planning aggressive motions of legged robots over rough terrain." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103432.
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Thesis: Sc. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 79-84).
Planning dynamic motions for a legged robot entails addressing both the continuous question of how its joints should move and the combinatorial question of which hand or foot should touch which surface and in what order. Fortunately, these two questions are linked by the centroidal dynamics of the robot, which we can express either in terms of its joint angle trajectories or in terms of its foot placements and applied forces. Based on this insight, I formulate a pair of mathematical programs for planning highly dynamic motions for legged robots. The first is a mixed-integer convex program, specifically, a mixed-integer quadratic program (MIQP), that yields a sequence of footholds/handholds as well as center of mass (COM) and angular momentum trajectories. The second is a trajectory optimization, formulated as a nonlinear program (NLP), that returns trajectories for the COM, angular momentum, and joint angles subject to the footholds/handholds chosen by the MIQP step. While any number of trajectory optimization schemes could be used here, we present one which is particularly useful in this case, as it enforces the system's dynamics directly in terms of its COM motion and angular momentum. As a result, the solution to the MIQP provides constraints (where each end-effector is required to make contact with the environment) for the NLP and also gives seeds for the decision variables corresponding to the robot's centroidal motion. Thus, the three primary contributions of this thesis are: an MIQP-based approach to gait selection over irregular terrain, a trajectory optimization formulation for floating-base systems subject to external forces and kinematic constraints, and a planning methodology that integrates both of those to generate highly dynamic motions in challenging environments. I apply these techniques to models of a quadruped and a humanoid (Boston Dynamics' LittleDog and Atlas respectively) to generate motion plans for running, jumping, and other dynamic behaviors.
by Andrés Klee Valenzuela.
Sc. D.
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Huskic, Goran [Verfasser], and Andreas [Akademischer Betreuer] Zell. "Control of Outdoor Robots at Higher Speeds on Challenging Terrain / Goran Huskic ; Betreuer: Andreas Zell." Tübingen : Universitätsbibliothek Tübingen, 2018. http://d-nb.info/117271634X/34.
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Brunner, Michael Verfasser], Christopher [Akademischer Betreuer] [Schlick, and Frank [Akademischer Betreuer] Flemisch. "Rough Terrain Motion Planning for Actively Reconfigurable Mobile Robots / Michael Brunner ; Christopher Schlick, Frank Flemisch." Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1156536324/34.
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Brunner, Michael [Verfasser], Christopher [Akademischer Betreuer] Schlick, and Frank [Akademischer Betreuer] Flemisch. "Rough Terrain Motion Planning for Actively Reconfigurable Mobile Robots / Michael Brunner ; Christopher Schlick, Frank Flemisch." Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1156536324/34.
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Fagegaltier, Laurent. "Planification multichemin pour les déplacements d'un véhicule tout-terrain." Montpellier 2, 1994. http://www.theses.fr/1994MON20027.
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Ce memoire de these traite la planification robuste et adaptative des deplacements d'un robot mobile sur terrain inegal. L'objectif est de fournir au systeme de navigation un ensemble de chemins et de lois de vitesse, pour permettre la modification rapide eventuelle du plan en cas de variations imprevues et importantes des parametres du vehicule et du terrain. Tout d'abord, le reseau des routes possibles est issu d'une representation discrete du terrain, et on lui associe un graphe des changements d'etats. Ensuite, la vitesse de progression est calculee a partir des caracteristiques du vehicule de type electrique (courbe couple/vitesse, puissance maximale, masse) et de celles du relief (pente, coefficient de frottement vehicule/sol). Les algorithmes presentes dans la these sont alors capables de trouver dans le graphe ainsi value plusieurs chemins de couts voisins. Ces algorithmes constituent des extensions de la recherche informee epsilon-admissible, classique en intelligence artificielle mais mal adaptee a une recherche multichemins. La rapidite du calcul et le nombre de chemins sont des objectifs concurrents que chacun des algorithmes tente de realiser differemment. La ressemblance entre les differents chemins et leur degre de ramification permettent enfin de les organiser en familles de solutions geographiquement voisines. Ceci facilite la reactivite du systeme de controle-commande, c'est-a-dire sa capacite a modifier le plan prevu initialement, en cas de degradation importante de l'environnement. Des resultats de simulation, utilisant comme critere le temps minimum, demontrent les qualites des algorithmes developpes
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Sistiaga, Marc. "Navigation référencée images de terrain pour engins sous-marins." Montpellier 2, 2000. http://www.theses.fr/2000MON20103.
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La navigation referencee images de terrain est un procede de positionnement qui permet la localisation du vehicule dans une carte globale representant la zone de travail. Pour cela, l'engin est equipe de capteurs a partir desquels il peut creer une image de son environnement local. Cette image locale est comparee a une image globale de terrain prealablement mise en memoire. Si une correspondance est trouvee, le vehicule peut calculer sa position et son orientation dans la zone cartographiee. Cette these presente une methode complete de navigation referencee images de terrain pour engins sous-marins. La technique proposee utilise soit des images de profondeur acquises par sondeur acoustique, soit des images video acquises par camera sous-marine. Tout d'abord, un lissage et une segmentation sont necessaires pour extraire de ces images des points caracteristiques. Des attributs differentiels, invariants a la translation et a la rotation, sont calcules en ces points pour realiser l'appariement des images. Un algorithme iteratif estime la position et l'orientation de l'image locale ainsi que le changement d'echelle entre les deux images, puis actualise l'ensemble des points apparies. L'estimation en ligne des variances des attributs permet l'utilisation d'outils probabilistes comme la distance de mahalanobis (seuillage) et la methode des moindres carres ponderes (estimation de la transformation).
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Pech, Thomas Joel. "A Deep-Learning Approach to Evaluating the Navigability of Off-Road Terrain from 3-D Imaging." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1496377449249936.
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Kwak, Se-Hung. "A computer simulation study of a free gait motion coordination algorithm for rough-terrain locomotion by a hexapod walking machine /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487267024996975.
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Livianu, Mathew Joseph. "Human-in-the-loop neural network control of a planetary rover on harsh terrain." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26576.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Dr. Ayanna Howard; Committee Member: Dr. Patricio Vela; Committee Member: Dr. Yoria Wardi. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Tidd, Brendan. "Learning visuo-motor behaviours for robot locomotion over difficult terrain." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/235891/1/Brendan%2BTidd%2BThesis%281%29.pdf.
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This thesis investigated efficient methods for learning locomotion behaviours for robots, and the challenges of combining several complex controllers. Experiments were performed with a dynamic biped in simulation required to walk across gaps, over steps and stairs, and jump over hurdles and blocks, and also in a real-world scenario with a large tracked platform negotiating small doorways. The developed solutions utilised perception to perform complex maneuvers while minimising retraining for new behaviours. Ideas from this thesis lead toward scalable behaviour libraries to enable robots to make their way into an increasing number of roles in our society.
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Brooks, Douglas Antwonne. "Control of reconfigurability and navigation of a wheel-legged robot based on active vision." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26545.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Howard, Ayanna; Committee Member: Egerstedt, Magnus; Committee Member: Vela, Patricio. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Sebastian, Bijo. "Traversability Estimation Techniques for Improved Navigation of Tracked Mobile Robots." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/94629.
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The focus of this dissertation is to improve autonomous navigation in unstructured terrain conditions, with specific application to unmanned casualty extraction in disaster scenarios. Robotic systems are being widely employed for search and rescue applications, especially in disaster scenarios. But a majority of these are focused solely on the search aspect of the problem. This dissertation proposes a conceptual design of a Semi-Autonomous Victim Extraction Robot (SAVER) capable of safe and effective unmanned casualty extraction, thereby reducing the risk to the lives of first responders. In addition, the proposed design addresses the limitations of existing state-of-the-art rescue robots specifically in the aspect of head and neck stabilization as well as fast and safe evacuation.
One of the primary capabilities needed for effective casualty extraction is reliable navigation in unstructured terrain conditions. Autonomous navigation in unstructured terrain, particularly for systems with tracked locomotion mode involves unique challenges in path planning and trajectory tracking. The dynamics of robot-terrain interaction, along with additional factors such as slip experienced by the vehicle, slope of the terrain, and actuator limitations of the robotic system, need to be taken into consideration. To realize these capabilities, this dissertation proposes a hybrid navigation architecture that employs a physics engine to perform fast and accurate state expansion inside a graph-based planner.
Tracked skid-steer systems experience significant slip, especially while turning. This greatly affects the trajectory tracking accuracy of the robot. In order to enable efficient trajectory tracking in varying terrain conditions, this dissertation proposes the use of an active disturbance rejection controller. The proposed controller is capable of estimating and counter acting the effects of slip in real-time to improve trajectory tracking. As an extension of the above application, this dissertation also proposes the use of support vector machine architecture to perform terrain identification, solely based on the estimated slip parameters.
Combining all of the above techniques, an overall architecture is proposed to assist and inform tele-operation of tracked robotic systems in unstructured terrain conditions. All of the above proposed techniques have been validated through simulations and experiments in indoor and simple outdoor terrain conditions.Doctor of Philosophy
This dissertation explores ways to improve autonomous navigation in unstructured terrain conditions, with specific applications to unmanned casualty extraction in disaster scenarios. Search and rescue applications often put the lives of first responders at risk. Using robotic systems for human rescue in disaster scenarios can keep first responders out of danger. To enable safe robotic casualty extraction, this dissertation proposes a novel rescue robot design concept named SAVER. The proposed design concept consists of several subsystems including a declining stretcher bed, head and neck support system, and robotic arms that conceptually enable safe casualty manipulation and extraction based on high-level commands issued by a remote operator. In order to enable autonomous navigation of the proposed conceptual system in challenging outdoor terrain conditions, this dissertation proposes improvements in planning, trajectory tracking control and terrain estimation. The proposed techniques are able to take into account the dynamic effects of robot-terrain interaction including slip experienced by the vehicle, slope of the terrain and actuator limitations. The proposed techniques have been validated through simulations and experiments in indoor and simple outdoor terrain conditions. The applicability of the above techniques in improving tele-operation of rescue robotic systems in unstructured terrain is also discussed at the end of this dissertation.
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Baleia, José Rodrigo Ferreira. "Haptic robot-environment interaction for self-supervised learning in ground mobility." Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/12475.
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Dissertação para obtenção do Grau de Mestre em
Engenharia Eletrotécnica e de ComputadoresThis dissertation presents a system for haptic interaction and self-supervised learning mechanisms to ascertain navigation affordances from depth cues. A simple pan-tilt telescopic arm and a structured light sensor, both fitted to the robot’s body frame, provide the required haptic and depth sensory feedback. The system aims at incrementally develop the ability to assess the cost of navigating in natural environments. For this purpose the robot learns a mapping between the appearance of objects, given sensory data provided by the sensor, and their bendability, perceived by the pan-tilt telescopic arm. The object descriptor, representing the object in memory and used for comparisons with other objects, is rich for a robust comparison and simple enough to allow for fast computations. The output of the memory learning mechanism allied with the haptic interaction point evaluation prioritize interaction points to increase the confidence on the interaction and correctly identifying obstacles, reducing the risk of the robot getting stuck or damaged. If the system concludes that the object is traversable, the environment change detection system allows the robot to overcome it. A set of field trials show the ability of the robot to progressively learn which elements of environment are traversable.
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Moignard, Christophe. "Planification et génération de mouvements en terrain inégal pour véhicule autonome à moteur thermique." Montpellier 2, 1992. http://www.theses.fr/1992MON20125.
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Ce memoire de these decrit une methode de planification de mouvements a temps minimal pour un vehicule autonome tout-terrain a moteur thermique, considere comme ponctuel sur une surface comportant des irregularites de relief, de resistance a l'avancement et de risque. Le relief du terrain est modelise par triangulation dynamique a partir des courbes de niveau et de points et lignes caracteristiques: cols, ponts, routes, cretes, etc. Des coefficients de mobilite, traduisant la nature du sol, et des coefficients de risque, traduisant les menaces, sont attribues aux elements de la triangulation. La trajectoire optimale ou sous-optimale au sens du temps de parcours minimum entre deux points de passage est donnee par un algorithme de recherche de type a*. La vitesse maximale possible est calculee a partir d'un modele du vehicule prenant en compte la caracteristique puissance/regime, les rapports et les rendements de la transmission. Le modele du terrain fournit les forces resistantes dues a la pente et a la nature du sol; la resistance aerodynamique, le devers et la force centrifuge dans les virages sont pris en compte. Le passage dans une zone a risque penalise le temps de parcours calcule. Un systeme complet et interactif a ete implante en common lisp sur une situation graphique. Les resultats des simulations demontrent l'aptitude du systeme a fournir a un navigateur embarque la suite des consignes de cap et de vitesse
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Fillatreau, Philippe. "Localisation et modélisation tridimensionnelles pour un robot mobile autonome tout terrain." Phd thesis, Université Paul Sabatier - Toulouse III, 1994. http://tel.archives-ouvertes.fr/tel-00261834.
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CETTE THESE TRAITE DU PROBLEME DE LA LOCALISATION DANS UN ENVIRONNEMENT TRIDIMENSIONNEL (3D) D'UN ROBOT MOBILE AUTONOME, AINSI QUE DE CELUI DE LA MODELISATION DE TERRAIN. DEUX DOMAINES TYPIQUES D'APPLICATION DE CE TRAVAIL SONT LA ROBOTIQUE MOBILE D'INTERVENTION (SECURITE CIVILE,) ET L'EXPLORATION PLANETAIRE. LA CONTRIBUTION DE LA THESE SE SITUE SURTOUT AU NIVEAU DE LA LOCALISATION D'UN ROBOT DANS UN ENVIRONNEMENT SEMI-STRUCTURE OU NON STRUCTURE. UN ETAT DE L'ART CONCERNANT D'UNE PART LES PRINCIPAUX CAPTEURS UTILISABLES, ET D'AUTRE PART LA MODELISATION, EST PRESENTE. L'ACCENT EST MIS SUR LES CAPTEURS INERTIELS ET SUR LA MODELISATION DE FORMES NON STRUCTUREES ; LE CHOIX DES CAPTEURS UTILISES, AINSI QUE CELUI DES PRIMITIVES GEOMETRIQUES RETENUES, SONT JUSTIFIES. DANS UN PREMIER TEMPS, UNE APPROCHE POUR LA LOCALISATION DU ROBOT A L'AIDE D'AMERS DE TYPE STRUCTURE, MAIS EVENTUELLEMENT NATURELS, EST PRESENTEE. LE PROBLEME DE LA FUSION INCREMENTALE D'UN MODELE DE LOCALISATION BASE SUR DES PRIMITIVES HETEROGENES, A PARTIR DE LA DETECTION DE LIGNES VERTICALES (ARBRES, COLONNES) OU DE MURS, EST TRAITE. PLUSIEURS APPROCHES POUR LE RECALAGE DE LA POSITION DU ROBOT ET LA FUSION DES DONNEES HETEROGENES SONT COMPAREES. UNE STRATEGIE DE CHOIX DES DIFFERENTS AMERS EST ENFIN PROPOSEE. DANS UN DEUXIEME TEMPS, LE PROBLEME DE LA MODELISATION DE TERRAIN ACCIDENTE ET DU RECALAGE SUR DES CARACTERISTIQUES NON STRUCTUREES DE L'ENVIRONNEMENT EST ABORDE. UNE METHODE DE MODELISATION DU TERRAIN PAR HIERARCHIE DE B-SPLINES EST PROPOSEE, ET LA CONSTRUCTION INCREMENTALE DU MODELE DE TERRAIN EST TRAITEE. LE MODELE ANALYTIQUE OBTENU PERMET D'EXTRAIRE DIVERS INVARIANTS 3D, COMME DES MAXIMA D'ALTITUDE OU DES POINTS DE FORTE COURBURE ; L'ASPECT MULTI-RESOLUTION PERMET DE FOCALISER PROGRESSIVEMENT LA RECHERCHE DE TELLES CARACTERISTIQUES. FINALEMENT, UNE METHODE DE LOCALISATION FAISANT COOPERER L'EXTRACTION DE CARACTERISTIQUES AVEC DES TECHNIQUES DE TYPE CORRELATION EST PROPOSEE. LES DIFFERENTES METHODES DEVELOPPEES ONT FAIT L'OBJET D'UNE VALIDATION SUR PLUSIEURS ROBOTS MOBILES EXPERIMENTAUX
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Seegmiller, Neal A. "Dynamic Model Formulation and Calibration for Wheeled Mobile Robots." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/460.
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Advances in hardware design have made wheeled mobile robots (WMRs) exceptionally mobile. To fully exploit this mobility, WMR planning, control, and estimation systems require motion models that are fast and accurate. Much of the published theory on WMR modeling is limited to 2D or kinematics, but 3D dynamic (or force-driven) models are required when traversing challenging terrain, executing aggressive maneuvers, and manipulating heavy payloads. This thesis advances the state of the art in both the formulation and calibration of WMR models We present novel WMR model formulations that are high-fidelity, general, modular, and fast. We provide a general method to derive 3D velocity kinematics for any WMR joint configuration. Using this method, we obtain constraints on wheel ground contact point velocities for our differential algebraic equation (DAE)-based models. Our “stabilized DAE” kinematics formulation enables constrained, drift free motion prediction on rough terrain. We also enhance the kinematics to predict nonzero wheel slip in a principled way based on gravitational, inertial, and dissipative forces. Unlike ordinary differential equation (ODE)-based dynamic models which can be very stiff, our constrained dynamics formulation permits large integration steps without compromising stability. Some alternatives like Open Dynamics Engine also use constraints, but can only approximate Coulomb friction at contacts. In contrast, we can enforce realistic, nonlinear models of wheel-terrain interaction (e.g. empirical models for pneumatic tires, terramechanics-based models) using a novel force-balance optimization technique. Simulation tests show our kinematic and dynamic models to be more functional, stable, and efficient than common alternatives. Simulations run 1K-10K faster than real time on an ordinary PC, even while predicting articulated motion on rough terrain and enforcing realistic wheel-terrain interaction models. In addition, we present a novel Integrated Prediction Error Minimization (IPEM) method to calibrate model parameters that is general, convenient, online, and evaluative. Ordinarily system dynamics are calibrated by minimizing the error of instantaneous output predictions. IPEM instead forms predictions by integrating the system dynamics over an interval; benefits include reduced sensing requirements, better observability, and accuracy over a longer horizon. In addition to calibrating out systematic errors, we simultaneously calibrate a model of stochastic error propagation to quantify the uncertainty of motion predictions. Experimental results on multiple platforms and terrain types show that parameter estimates converge quickly during online calibration, and uncertainty is well characterized. Under normal conditions, our enhanced kinematic model can predict nonzero wheel slip as accurately as a full dynamic model for a fraction of the computation cost. Finally, odometry is greatly improved when using IPEM vs. manual calibration, and when using 3D vs. 2D kinematics. To facilitate their use, we have released open source MATLAB and C++ libraries implementing the model formulation and calibration methods in this thesis.
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Morlans, Richard. "Génération des trajectoires d'un robot d'exploration planétaire utilisant un modèle numérique de terrain issu d'images prises par satellite." Montpellier 2, 1992. http://www.theses.fr/1992MON20119.
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Ce memoire de these decrit un systeme de generation de trajectoires pour robot mobile d'exploration de la planete mars a partir de modeles numeriques du terrain (m. N. T. ) issus d'images supposees prises par un orbiteur. Le m. N. T. Est d'abord filtre pour supprimer le bruit specifique au modele. Des points (cols) et lignes (talwegs) privilegies pour le deplacement du robot sont extraits automatiquement du m. N. T. Les cols sont detectes par une analyse de chaque point du m. N. T. Et de son voisinage. Les talwegs sont ensuite construits a partir de ces cols par application de regles heuristiques de comportement. Le resultat est un reseau connexe de segments de talwegs, stocke dans une base de donnees de type relationnelle. Une topologie du terrain en est deduite a partir des informations disponibles. Un graphe de recherche est ensuite construit a partir de ce reseau, en ponderant les arcs par une fonction de cout representative de l'effort et du risque necessaires a la traversee d'un segment du reseau par le vehicule. Un parcours de ce graphe par un algorithme heuristique nous fournit une premiere trajectoire. Une partition du terrain en regions de cout de navigation homogene est ensuite effectuee. Celle-ci nous permet de rechercher des raccourcis a l'interieur de regions, ameliorant ainsi des portions du chemin localement sous-optimales
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Deremetz, Mathieu. "Contribution à la modélisation et à la commande de robots mobiles autonomes et adaptables en milieux naturels." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC079/document.
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Les problématiques de recherche abordées dans cette thèse concernent la conceptualisation, la modélisation et la commande générique des robots mobiles lors de leur évolution en milieux extérieurs et en présence de glissement pour des applications de suivi de précision. Ainsi, ce mémoire synthétise dans un premier temps les développements et résultats obtenus lors du suivi de trajectoire (localisation absolue), puis synthétise ensuite ceux obtenus lors de suivi de structure et de cible (localisation relative). Une dernière partie introduit un concept de plateforme robotique reconfigurable et sa commande associée pour adapter l’assiette et les dimensions du châssis en fonction de la topographie du terrain.Pour chaque application de suivi, ce mémoire présente un panel de lois de commande originales pour des robots différentiels, à un train et à deux trains directeurs. Chaque modalité de commande est présentée en quatre étapes : modélisation, estimation, commande et expérimentations. La première contribution majeure de la thèse concerne l’estimation du glissement. Cette dernière est adaptative et basée modèle. Elle intègre la modélisation cinématique étendue seule ou couplée à la modélisation dynamique du robot mobile pour assurer une estimation intègre quels que soient la vitesse, les phénomènes dynamiques rencontrés et la nature du sol. La seconde contribution majeure concerne le développement d’une stratégie de commande générique pour les robots mobiles. Cette stratégie est basée sur le principe de la commande en cascade (ou par backstepping) et est déclinée dans ce mémoire à travers un panel de lois de commande. Cette méthodologie de commande, lorsqu’elle est associée à l’observation du glissement précédent, permet d’obtenir des performances de suivi accrues quel que soit le contexte rencontré. L’ensemble des algorithmes ont été validés en simulation et/ou expérimentalement à l’aide de différentes plateformes robotiques en contextes réelsThis work is focused on the conceptualization, the modeling and the genericcontrol of mobile robots when moving in off-road contexts and facing slipperyterrains, especially for very accurate tracking and following applications. Thisthesis summarizes the proposed methods and the obtained results to addressthis research issue, first for path following applications (absolute localization)and then for edge and target tracking applications (relative localization). A finalsection of this thesis introduces an adaptive robotic concept and its associatedcontroller allowing the adaptation of the pose (position and orientation) of thechassis with respect to the environment topography.For each application, this thesis introduces a panel of innovative control algorithmsfor controlling skid-steering, two-wheel steering and four-wheel steeringmobile robots. Each algorithm of the panel is described, in this thesis, infour steps : modeling, estimation, control and experiments.The first main contribution of this thesis deals with the slippage estimation.The latter is adaptive and model-based. It also includes the extended kinematicmodeling only or together with the dynamic modeling of the mobile robot toensure a robust estimation of the slippage whatever the speed of the robot, encountereddynamic phenomena or even ground characteristics.The second main contribution deals with the design of a generic control approachfor mobile robots when path following and target tracking. The proposedstrategy is mostly based on a backstepping method and is illustrated inthis thesis via a panel of control laws. When combining this proposed controlapproach with the slippage estimation described above, significant improvedtracking and following performances are obtained (in term of stability, repeatability,accuracy and robustness) whatever the encountered context.All algorithms have been tested and validated through simulations and/orfull-scale experiments, indoor and off-road, with different mobile robots
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Tremblay, Jean-François, and Jean-François Tremblay. "Forest inventory with a lidar-equipped robot for difficult environments." Master's thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/37634.
Full textAbstract:
La foresterie est une industrie majeure dans plusieurs parties du monde. Elle dépend de l’inventaire forestier, qui consiste en la mesure des attributs des arbres. Dans ce mémoire, nous proposons l’utilisation de la cartographie 3D, basée sur l’algorithme itervative closest point, pour automatiquement mesurer des diamètres d’arbres à partir d’observations d’un robot mobile. Bien que des études précédentes démontraient le potentiel d’une telle technologie, elles présentaient des lacunes en terme de rigueur d’analyse et ne fonctionnaient pas dans des environnements forestiers difficiles. Nous avons validé plusieurs méthodes pour l’estimation de diamètre, dont deux nouvelles, avec un jeu de données nouveau et varié comportant quatre sites forestiers, 11 trajectoires de robot totalisant 1458 observations d’arbre et 1.4 hectares de forêt. De plus, nous faisons des recommendations sur le déploiement de robots mobiles dans un contexte forestier. Nous concluons que notre méthode de cartographie est utilisable dans le contexte de l’inventaire forestier automatisé, avec notre meilleure méthode donnant une erreur quadratique de 3:45 cm pour notre jeu de données en entier et 2:04 cm dans des conditions idéales, c’est-à-dire une forêt mature et espacée.La foresterie est une industrie majeure dans plusieurs parties du monde. Elle dépend de l’inventaire forestier, qui consiste en la mesure des attributs des arbres. Dans ce mémoire, nous proposons l’utilisation de la cartographie 3D, basée sur l’algorithme itervative closest point, pour automatiquement mesurer des diamètres d’arbres à partir d’observations d’un robot mobile. Bien que des études précédentes démontraient le potentiel d’une telle technologie, elles présentaient des lacunes en terme de rigueur d’analyse et ne fonctionnaient pas dans des environnements forestiers difficiles. Nous avons validé plusieurs méthodes pour l’estimation de diamètre, dont deux nouvelles, avec un jeu de données nouveau et varié comportant quatre sites forestiers, 11 trajectoires de robot totalisant 1458 observations d’arbre et 1.4 hectares de forêt. De plus, nous faisons des recommendations sur le déploiement de robots mobiles dans un contexte forestier. Nous concluons que notre méthode de cartographie est utilisable dans le contexte de l’inventaire forestier automatisé, avec notre meilleure méthode donnant une erreur quadratique de 3:45 cm pour notre jeu de données en entier et 2:04 cm dans des conditions idéales, c’est-à-dire une forêt mature et espacée.
Forestry is a major industry in many parts of the world. It relies on forest inventory, which consists of measuring tree attributes. In this thesis, we propose the use of 3D mapping, based on the iterative closest point algorithm, to automatically measure tree diameters in forests from mobile robot observations. While previous studies showed the potential for such technology, they lacked a rigorous analysis of diameter estimation methods in challenging forest environments. Here, we validated multiple diameter estimation methods, including two novel ones, in a new varied dataset of four different forest sites, 11 trajectories, totalling 1458 tree observations and 1.4 hectares. We provide recommendations for the deployment of mobile robots in a forestry context. We conclude that our mapping method is usable in the context of automated forest inventory, with our best method yielding a root mean square error of 3:45 cm for our whole dataset, and 2:04 cm in ideal conditions consisting of mature forest with well spaced trees.
Forestry is a major industry in many parts of the world. It relies on forest inventory, which consists of measuring tree attributes. In this thesis, we propose the use of 3D mapping, based on the iterative closest point algorithm, to automatically measure tree diameters in forests from mobile robot observations. While previous studies showed the potential for such technology, they lacked a rigorous analysis of diameter estimation methods in challenging forest environments. Here, we validated multiple diameter estimation methods, including two novel ones, in a new varied dataset of four different forest sites, 11 trajectories, totalling 1458 tree observations and 1.4 hectares. We provide recommendations for the deployment of mobile robots in a forestry context. We conclude that our mapping method is usable in the context of automated forest inventory, with our best method yielding a root mean square error of 3:45 cm for our whole dataset, and 2:04 cm in ideal conditions consisting of mature forest with well spaced trees.
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Denis, Dieumet. "Contribution à la modélisation et à la commande de robots mobiles reconfigurables en milieu tout-terrain : application à la stabilité dynamique d'engins agricoles." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22565/document.
Full textAbstract:
La thématique étudiée dans ce mémoire est axée sur la préservation de la stabilité dynamique de véhicules évoluant en environnement naturel. En effet, la mobilité en milieu tout-terrain est une activité particulièrement pénible et dangereuse en raison de la nature difficile de l'environnement de conduite et de la reconfigurabilité des machines. Le caractère changeant et incertain des interactions rencontrées entre des véhicules à dynamique complexe et variable et leur environnement entraîne régulièrement des risques accrus de renversement et/ou de perte de contrôle (dévalement, dérapage déclenché par une perte soudaine d'adhérence) pour le conducteur. Une forte accidentalité mortelle est, en effet, recensée dans ce secteur, en particulier, dans le milieu agricole ou le renversement de véhicule est classé comme étant la première cause de mortalité au travail. A l'heure actuelle, les approches existantes sur la stabilité d'engins agricoles sont qualifiées à juste titre de passives car elles ne permettent pas d'éviter que les accidents ne se produisent. Par ailleurs, la transposition directe des solutions de sécurité active du secteur de l'automobile (ABS, ESP) s'est révélée inadaptée aux véhicules tout-terrain a cause des hypothèses simplificatrices (routes plates et homogènes, conditions d'adhérence constantes, etc.) dont souffre la conception de ces dispositifs. Ainsi, le développement de systèmes actifs de sécurité prenant en compte les spécificités de la conduite en milieu tout-terrain se révèle être la meilleure voie d'amélioration à suivre. Eu égard à ces circonstances, ce projet se propose d'adresser cette problématique en étudiant des métriques de stabilité pertinentes permettant d'estimer et d'anticiper en temps réel les risques afin de permettre des actions correctives pour la préservation de l'intégrité des machines tout-terrain. Afin de faciliter l'industrialisation du dispositif actif de sécurité conçu, l'une des contraintes sociétales et commerciales de ce projet a été l'utilisation de capteurs compatibles avec le coût des machines visées. L'objectif ambitieux de cette étude a été atteint par différentes voies. En premier lieu, une approche de modélisation multi-échelle a permis de caractériser l'évolution dynamique de véhicules en milieu tout-terrain. Cette approche à dynamique partielle a offert l'avantage de développer des modèles suffisamment précis pour être représentatifs du comportement réel de l'engin mais tout en présentant une structure relativement simple permettant la synthèse d'asservissements performants. Puis, une étude comparative des avantages et des inconvénients des trois grandes familles de métriques répertoriées dans la littérature a permis de mettre en exergue l'intérêt des métriques analytiques à modèle dynamique par rapport aux catégories de critères de stabilité dits statiques et empiriques. Enfin, l'analyse approfondie des métriques dynamiques a facilité le choix de trois indicateurs (Lateral and Longitudinal Load Transfer (LLT), Force Angle Stability Measurement (FASM) et Dynamic Energy Stability Measurement (DESM)) qui sont représentatifs d'un risque imminent de renversement du véhicule. La suite du mémoire s'appuie sur la théorie d'observation pour l'estimation en ligne des variables non directement mesurables en milieu tout-terrain telles que les rigidités de glissement et dérive du pneumatique. Jumelée aux différents modèles dynamiques du véhicule, la synthèse d'observateurs a permis donc d'estimer en temps réel les efforts d'interaction pneumatiques-sol nécessaires à l'évaluation des indicateurs d'instabilité. Le couplage de ces modèles multi-échelles à la théorie d'observation a ainsi constitué un positionnement original à même de briser la complexité de la caractérisation de la stabilité de véhicules à dynamiques complexes et incertaines. (...)This work is focused on the thematic of the maintenance of the dynamic stability of off-road vehicles. Indeed, driving vehicles in off-road environment remains a dangerous and harsh activity because of the variable and bad grip conditions associated to a large diversity of terrains. Driving difficulties may be also encountered when considering huge machines with possible reconfiguration of their mechanical properties (changes in mass and centre of gravity height for instance). As a consequence, for the sole agriculture sector, several fatal injuries are reported per year in particular due to rollover situations. Passive protections (ROllover Protective Structure - ROPS) are installed on tractors to reduce accident consequences. However, protection capabilities of these structures are very limited and the latter cannot be embedded on bigger machines due to mechanical design limitations. Furthermore, driving assistance systems (such as ESP or ABS) have been deeply studied for on-road vehicles and successfully improve safety. These systems usually assume that the vehicle Center of Gravity (CG) height is low and that the vehicles are operating on smooth and level terrain. Since these assumptions are not satisfied when considering off-road vehicles with a high CG, such devices cannot be applied directly. Consequently, this work proposes to address this research problem by studying relevant stability metrics able to evaluate in real time the rollover risk in order to develop active safety devices dedicated to off-road vehicles. In order to keep a feasible industrialization of the conceived active safety device, the use of compatible sensors with the cost of the machines was one of the major commercial and societal requirements of the project. The ambitious goal of this study was achieved by different routes. First, a multi-scale modeling approach allowed to characterize the dynamic evolution of off-road vehicles. This partial dynamic approach has offered the advantage of developing sufficiently accurate models to be representative of the actual behavior of the machine but having a relatively simple structure for high-performance control systems. Then, a comparative study of the advantages and drawbacks of the three main families of metrics found in the literature has helped to highlight the interest of dynamic stability metrics at the expense to categories of so-called static and empirical stability criteria. Finally, a thorough analysis of dynamic metrics has facilitated the choice of three indicators (Longitudinal and Lateral Load Transfer (LLT), Force Angle Stability Measurement (FASM) and Dynamic Energy Stability Measurement (DESM)) that are representative of an imminent rollover risk. The following of the document is based on the observation theory for estimating online of variables which are not directly measurable in off-road environment such as slip and cornering stiffnesses. Coupled to the dynamic models of the vehicle, the theory of observers has helped therefore to estimate in real time the tire-soil interaction forces which are necessaries for evaluating indicators of instability. The coupling of these multiscale models to the observation theory has formed an original positioning capable to break the complexity of the characterization of the stability of vehicles having complex and uncertain dynamics. (...)