Les robots à pattes promettent de pouvoir marcher sur des terrains irréguliers, voire accidentés. Ils trouvent dès aujourd'hui une application ludo- éducative. Nous présentons la plateforme Metabot, un robot quadrupède open-source, qui a été développée pour l'éducation. Cette dernière s'inscrit dans le contexte technologique actuel, qui permet, grâce à un accès au prototypage rapide et aux composants sur étagère de construire des robots à pattes autrefois présents uniquement dans les laboratoires. Cette plateforme a été utilisée dans l'enseignement secondaire, afin de permettre à des élèves de découvrir la robotique, ainsi que la programmation. Nous décrivons par la suite un environnement mis au point dans le but d'étudier la locomotion des robots à pattes, en étendant le contrôleur expert développé sur Metabot à une plus grande famille de robots. Nous avons réalisé une série d'expériences en simulation sur moteur physique que nous avons analysées dans le but de mieux comprendre les règles qui régissent la locomotion des robots à pattes. Enfin, nous nous intéressons à la locomotion bipède, qui pose le problème de la stabilité. Lors du développement de notre plateforme Sigmaban, un petit robot humanoïde conçu pour participer à la RoboCup, nous avons créé un capteur permettant d'estimer le centre de pression du robot. Nous exploitons ce dernier pour améliorer la stabilité latérale du robot, en créant ainsi une marche en boucle fermée. / A promise of legged robots is being able walking on irregular or uneven floor. It is already used nowadays in education and entertainment applications. We introduce the Metabot platform, an open-source quadruped robot developped for education. This takes place in current technological context which allows, thanks to an access to fast prototyping and off-shelf components, building legged robots that were formerly only present in laboratories. This platform was used for teaching in secondary schools, allowing students to discover robotics, and especially programming. We then describe an environment designed to study legged robots locomotion, extending the expert controller designed for Metabot. We realized some physics simulation experiments and analyzed it to get a better understanding of the legged locomotion underlying rules. At last, we get a closer look at biped locomotion, for which stability problems arise. When developping our Sigmaban platform, a small-sized humanoid robot created to participate in RoboCup soccer, we designed foot pressure sensors that allow us to estimate the robot center of pressure. We exploit these sensors to improve the lateral stability on the robot, creating a closed-loop walk.

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-05-18T11:36:06Z No. of bitstreams: 1 arquivototal.pdf: 10156219 bytes, checksum: b07b75a7a10dfb56dd494879971fa975 (MD5) / Made available in DSpace on 2016-05-18T11:36:06Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 10156219 bytes, checksum: b07b75a7a10dfb56dd494879971fa975 (MD5) Previous issue date: 2009-03-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Among the methods of controlling insect pests, the use of pesticides has been reduced in negative consequences on the beneficial fauna and the environment, so it is therefore necessary to search for alternatives that minimize the adverse effects of pesticides on the environment. As alternatives to control pests, are being studied, several other techniques, which includes the use of origin plant substances because they have low toxicity to humans and animals, and for presenting performance against several species of pests, which assumes increasing importance in programs of integrated pest management (MIP), especially at a time when it discusses very integrated production towards sustainable agriculture. The insects belonging to the order Dermaptera, are still not well known and the information in the literature, characterized as predatory bodies with good ability. Among the biological agents with characteristics suitable for this purpose, the dermápteros have attracted great attention because predators are greedy, that is, with high ability to attack and feeding on different prey, particularly of eggs and immature stages insects of the orders Lepidoptera, Hemiptera, Coleoptera and Diptera. Considering the potential use of preying on programs for biological control, studies related to their biology and their selectivity in plant extracts become indispensable. Thus, the aim of this work was to study the biological aspects of Euborellia annulipes fed on Spodoptera frugiperda and Hyadaphis foeniculi and selectivity of this predator to products of plant origin in laboratory conditions. / Dentre os métodos de controle de insetos-praga, o uso de agrotóxicos vem sendo reduzido, em conseqüências negativas sobre a fauna benéfica e sobre o ambiente, fazendo-se, portanto, necessário a busca de alternativas que minimizem os efeitos adversos dos agrotóxicos sobre o meio ambiente. Como alternativas ao controle de pragas, estão sendo estudadas, várias outras técnicas, nas quais se inclui o uso de substâncias de origem vegetal, por terem baixa toxicidade ao homem e animais, e por apresentarem eficiência contra várias espécies de pragas, que assume importância cada vez maior em programas de manejo integrado de pragas (MIP), principalmente em um momento em que se discute muito a produção integrada rumo a uma agricultura sustentável. Os insetos pertencentes à ordem Dermaptera, ainda não são bem conhecidos e as informações existentes na literatura, os caracterizam como organismos com boa capacidade predatória. Dentre os agentes biológicos com características adequadas a esta finalidade, os Dermápteros têm despertado grande atenção, pois são predadores vorazes, isto é, com alta capacidade de ataque e que se alimentam de diversas presas, particularmente, de ovos e fases imaturas de insetos das ordens Lepidoptera, Hemiptera, Coleoptera e Diptera. Considerando-se o potencial de uso desse predador em programas de controle biológico, os estudos relacionados a sua biologia e a sua seletividade a extratos vegetais tornam-se imprescindíveis. Diante disso, o objetivo desse trabalho foi de estudar os aspectos biológicos de Euborellia annulipes alimentada com Spodoptera frugiperda e Hyadaphis foeniculi, e a seletividade desse predador a produtos de origem vegetal em condições de laboratório.

Running, jumping and walking are physical activities that are performed by humans in a simple and efficient way. However, these types of movements are difficult to perform by humanoid robots. Humans perform these activities without difficulty thanks to their ability to absorb the ground impact force. The absorption of the impact force is based on the human ability to vary muscles stiffness. The principal objective of this dissertation is to study vertical jumps in order to reduce the impact force in the landing phase of the jump motion of humanoid robots. Additionally, the impact force reduction is applied to an arm-oriented movement with the objective of preserving the integrity of falling humanoid robot. This dissertation focuses on researching vertical jump motions by designing, implementing and testing variable stiffness control strategies based on Computed-Torque Control while tracking desired trajectories calculated using the Zero Moment Point (ZMP) and the Center of Mass (CoM) conditions. Variable stiffness method is used to reduce the impact force during the landing phase. The variable stiffness approach was previously presented by Pratt et al. in [1], where they proposed that full stiffness is not always required. In this dissertation, the variable stiffness capability is implemented without the integration of any springs or dampers. All the actuators in the robot are DC Motors and the lower stiffness is achieved by the design and implementation of PID gain values in the PID controller for each motor. The current research proposes two different approaches to generate variable stiffness. The first approach is based on an optimal control theory where the linear quadratic regulator is used to calculate the gain values of the PID controller. The second approach is based on Fuzzy logic theory and it calculates the proportional gain (KP) of the PID controller. Both approaches are based on the idea of computing the PID gains to allow for the displacement of the DC motor positions with respect to the target positions during the landing phase. While a DC motor moves from the target position, the robot CoM changes towards a lower position reducing the impact force. The Fuzzy approach uses an estimation of the impact velocity and a specified desired soft landing level at the moment of impact in order to calculate the P gain of the PID controller. The optimal approach uses the mathematical model of the motor and the factor, which affects the Q matrix of the Linear Quadratic Regulator (LQR), in order to calculate the new PID values. A One-legged robot is used to perform the jump motion verification in this research. In addition, repeatability experiments were also successfully performed with both the optimal control and the Fuzzy logic methods. The results are evaluated and compared according to the impact force reduction and the robot balance during the landing phase. The impact force calculation is based on the displacement of the CoM during the landing phase. The impact force reduction is accomplished by both methods; however, the robot balance shows a considerable improvement with the optimal control approach in comparison to the Fuzzy logic method. In addition, the Optimal Variable Stiffness method was successfully implemented and tested in Falling Robots. The robot integrity is accomplished by applying the Optimal Variable Stiffness control method to reduce the impact force on the arm joints, shoulders and elbows.

Indiana University-Purdue University Indianapolis (IUPUI) / Khakpour, Zahra M.S.M.E., Purdue University, May 2017. Multibody Dynamics Model of A Full Human Body For Simulating Walking, Major Professor: Hazim El-Mounayri. Bipedal robotics is a relatively new research area which is concerned with creating walking robots which have mobility and agility characteristics approaching those of humans. Also, in general, simulation of bipedal walking is important in many other applications such as: design and testing of orthopedic implants; testing human walking rehabilitation strategies and devices; design of equipment and facilities for human/robot use/interaction; design of sports equipment; and improving sports performance & reducing injury. One of the main technical challenges in that bipedal robotics area is developing a walking control strategy which results in a stable and balanced upright walking gait of the robot on level as well as non-level (sloped/rough) terrains. In this thesis the following aspects of the walking control strategy are developed and tested in a high-fidelity multibody dynamics model of a humanoid body model: 1. Kinematic design of a walking gait using cubic Hermite splines to specify the motion of the center of the foot. 2. Inverse kinematics to compute the legs joint angles necessary to generate the walking gait. 3. Inverse dynamics using rotary actuators at the joints with PD (Proportional-Derivative) controllers to control the motion of the leg links. The thee-dimensional multibody dynamics model is built using the DIS (Dynamic Interactions Simulator) code. It consists of 42 rigid bodies representing the legs, hip, spine, ribs, neck, arms, and head. The bodies are connected using 42 revolute joints with a rotational actuator along with a PD controller at each joint. A penalty normal contact force model along with a polygonal contact surface representing the bottom of each foot is used to model contact between the foot and the terrain. Friction is modeled using an asperity-based friction model which approximates Coulomb friction using a variable anchor-point spring in parallel with a velocity dependent friction law. In this thesis, it is assumed in the model that a balance controller already exists to ensure that the walking motion is balanced (i.e. that the robot does not tip over). A multi-body dynamic model of the full human body is developed and the controllers are designed to simulate the walking motion. This includes the design of the geometric model, development of the control system in kinematics approach, and the simulation setup.

No description available.

付記する学位プログラム名: グローバル生存学大学院連携プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22771号 / 工博第4770号 / 新制||工||1746(附属図書館) / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 松野 文俊, 教授 椹木 哲夫, 教授 泉田 啓 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This thesis contains the design, manufacturing, and testing of a functional eight-legged robotic transporter based on the concept design laid out in U.S. Patent 7,246,671. The device is intended to achieve three different sequences of motion: regular driving, obstacle climbing, and stair climbing. The prototype was carried through concept design, analysis, selection of materials and components, manufacturing, software development, and final assembly and testing. The device can be assembled under multiple configurations, which harbor certain advantages and disadvantages. The results of the testing encourage the continuation of a second iteration of this concept.

The objectives of this study were to implement force sensors on the feet of a bipedal robot and analyze their response at different conditions. The data will be used to design a control strategy for the robot. The powered joints of the robot are driven by linear motors. A force sensor circuit was made and calibrated with different kinds of weight. A trajectory generator and inverse kinematics calculator for the robot were made to control the robot walking movement in an open-loop manner. The force data were taken at a certain period of time when the robot was in a standing position. Experiments with external disturbances were also performed on the robot. The ZMP position and mass of the robot were calculated by using the data of force sensors. The force sensor circuit was reliable in taking and handling the data from the sensor although the noise from the motors of the robot was present. / <p>Validerat; 20111115 (anonymous)</p>

Autonomous robots are employed in several important tasks, for example, from health care to military and defense applications involving operations in hazardous and inaccessible environments. Legged autonomous robots can be advantageous due to high adaptability and stability over any terrain, superior obstacle avoidance capability, and advantages through redundancy by utilizing multiple legs. Compared to rigid-legged robots, flexible-legged robots are highly compliant, suitable for non-destructive inspection applications, and possess enhanced gait control with improved energy efficiency. An approach to designing flexible-legged robots is to mimic desirable features evolved via natural selection in biological organisms. Conceptualizing new biologically inspired flexible-legged robots can expand the usability and improve the efficiency of robots in different applications. In this project, the inspiration for locomotion design is the mobility principle utilized by small-scale organisms in the form of beating protrusions referred to as cilia or flagella. Notably, the collective beating dynamics of ciliary arrays reveal essential characteristics such as synchronization, phase locking, and metachronal coordination suitable for terrestrial and aquatic robot locomotion. This thesis presents the formulation, simulation, and analysis of a planar bio-inspired flexible-legged robot for terrestrial locomotion. Each leg of the robot is modeled as a bundle of flexible filaments using constrained Euler elastica that is suitable to describe some of the characteristics of cilia or flagella. The legs/protrusions are mechanically coupled through the base, representing the robot's payload, via linear springs or elastic lumped elements, to produce certain desired collective beating patterns upon individual moment actuations. The locomotion mechanism is illustrated in simulation, wherein the results pave the ground for future work with refined modeling to account for hardware implementation constraints.

The aim of this dissertation is to systematically construct a hierarchical framework that allows for robust multi-agent collaborative legged locomotion. More specifically, this work provides a detailed derivation of a torque controller that is theoretically justifiable in the context of Hybrid Zero Dynamics at the lowest level of control to produce highly robust locomotion, even when subject to uncertainty. The torque controller is based on virtual constraints and partial feedback linearization and is cast into the form of a strictly convex quadratic program. This partial feedback linearization is then relaxed through the use of a defect variable, where said defect variable is allowed only to change in a manner that is consistent with rapidly exponentially stable output dynamics through the use of a Control Lyapunov Function. The torque controller is validated in both simulation and on hardware to demonstrate the efficacy of the approach. In particular, the robot is subject to payload and push disturbances and is still able to remain stable. Furthermore, the continuity of the torque controller, in addition to robustness analysis of the periodic orbit, is also provided. At the next level of control, we consider emulating the Single Rigid Body model through the use of Behavioral Systems Theory, resulting in a data-driven model that adequately describes a quadruped at the reduced-order level. Still, due to the complexity and a considerable number of variables in the problem, the model further undergoes a $2$-norm approximation, resulting in a model that is computationally efficient enough to be used in a real-time manner for trajectory planning. In order to test the method rigorously, we consider a series of experiments to examine how the planner works when using different gait parameters than that which was used during data collection. Furthermore, the planner is compared to the traditional Single Rigid Body model to test its efficacy for reference tracking. This data-driven model is then extended to the multi-agent case, where each agent is rigidly holonomically constrained to one another. In this case, the model is used in a distributed manner using a one-step communication delay such that the coupling between agents can be adequately considered while spreading the computational demand. The trajectory planner is evaluated through various hardware experiments with three agents, and simulations are also used to display the scalability of the approach by considering five robots. Finally, this dissertation examines how traditional reduced-order models can be used in tandem with data-based models to reap the benefits of both methods. More specifically, an interconnected Single Rigid Body model is considered, where the interaction forces are described via a data-driven model. Simulations are provided to display the efficacy of this approach at the reduced order level and show that the interaction forces can be reduced by considering them in the trajectory planner. As in the previous cases, this is followed by experimental evaluation subject to external forces and different terrains. / Doctor of Philosophy / The goal of this dissertation is to create a layered control scheme for teams of quadrupeds that results in stable and robust locomotion, including a high-level trajectory planner and a low-level controller. More specifically, this work outlines an optimal torque-based whole-body controller that operates at the joint level to track desired trajectories. These trajectories are obtained by a high-level trajectory planner, which utilizes a data-driven predictive controller to create an optimal trajectory without explicitly requiring knowledge of a model. The hierarchical control scheme is then extended to consider collaborative locomotion. Namely, this work considers teams of quadrupeds that are rigidly connected to one another such that there is no relative motion between them. There are potentially large interaction forces that are applied between the robots that cannot be measured, which can result in instability. Furthermore, the models used to describe the interconnected system are prohibitively complex when being used for trajectory planning. For this reason, the data-driven model considered for a single robot is extended to create a centralized model that encapsulates not only the motion of a single robot but also its connection constraints. The resulting model is very large, making it difficult to use in a real-time manner. Therefore, this work outlines how to distribute the model such that each robot can locally plan for its own motion while also considering the coupling between them. Finally, this work provides one additional extension that combines a traditional physics-based model with a data-driven model to capitalize on the strengths of each. In particular, a physics-based model is considered as a baseline, while a data-driven model is used to describe the interaction forces between robots. In using this final extension, both improved solve times and smoother locomotion are achieved. Each of the aforementioned methods is tested thoroughly through both simulations and experiments.