Humanoid Robots

For many years, the human being has been trying, in all ways, to recreate the complex mechanisms that form the human body. Such task is extremely complicated and the results are not totally satisfactory. However, with increasing technological advances based on theoretical and experimental researches, man gets, in a way, to copy or to imitate some systems of the human body. These researches not only intended to create humanoid robots, great part of them constituting autonomous systems, but also, in some way, to offer a higher knowledge of the systems that form the human body, objectifying possible applications in the technology of rehabilitation of human beings, gathering in a whole studies related not only to Robotics, but also to Biomechanics, Biomimmetics, Cybernetics, among other areas. This book presents a series of researches inspired by this ideal, carried through by various researchers worldwide, looking for to analyze and to discuss diverse subjects related to humanoid robots. The presented contributions explore aspects about robotic hands, learning, language, vision and locomotion

Estimating sauropod body mass and gait : by the analysis of recent and fossil tetrapod tracks with photogrammetry and soil mechanics

This dissertation presents an analysis of recent and fossil tracks with quantitative and in-terdisciplinary methods for estimating the body mass and locomotion of a sauropod trackmaker. By employing methods from natural and engineering sciences, this research demonstrates that interdisciplinary research on tetrapod tracks can provide insights beyond conventional paleontological research. The novelty in this dissertation is that it brings as-pects from traditional vertebrate ichnology together with modern methods and considera-tions from biomechanics and soil mechanics to gain additional information about sauropod paleobiology. Track and trackways are structures left behind by an animal. Their formation is dependent on the substrate (i.e., soil or sediment) that contains the tracks, as well as the anatomy and locomotion of the trackmaker. Fossil tracks can provide a great deal of information about the extinct trackmaker, such as type, size, speed, behavior, and even pathologies. Although, it would be intuitive to think that the body mass of the trackmaker can also be determined from tracks, this has not been done before. Particularly, since body mass, which, for example, can reach record-breaking values in the case of the sauropod dinosaurs, is one of the fundamental attributes of any animal. Common mass estimation methods require body fossils for reconstructing density/volume or to make scaling relationships from long bones. However, body fossils are usually not available in most tracksites due to preservation conditions. Thus, estimating the weight of the trackmaker from its tracks, both extant and extinct, is the object of research in this dissertation. For determining the exact geometry and dimensions of both recent and fossil tracks, pre-cise documentation is required. Photogrammetry is a method from geodesy that has proved to be very useful for vertebrate ichnology. It uses digital images to generate three-dimensional (3D) models. The interpretability of these 3D models is improved by the geo-logical method of vertical exaggeration, which stretches the vertical axis of a model to vis-ualize previously unseen structures in the tracks. Applying vertical exaggeration is novel to vertebrate ichnology and reveals important information of the trackmaker from its tracks, such as travel direction and anatomical details of the hands and feet. To test if estimating the weight from fossil tracks is feasible, studying recent trackmakers for calibration is necessary. Elephants are the largest living land animals and often used as living analogs to the extinct sauropod dinosaurs. Elephant footprints are digitized and used as the basis of a numerical simulation (finite element analysis), constrained by the substrate properties. The load required to generate these footprints was reconstructed and the ele-phant’s weight was back calculated. Although, weight estimation for a recent trackmaker is possible with an error of about 15%, careful assessment of the influence of the trackmak-er’s locomotion is also important. For fossil trackmakers, precise evaluation of the locomo-tion, let alone the gait, is difficult to ascertain from tracks. The main gaits, such as walk, trot, pace, and gallop, are determined by studying horses, which make them a prime exam-ple for understanding locomotion from tracks. Together with basic estimations of the trackmaker’s size, it is possible to estimate the gait from tracks. Different gaits also mean varying distribution of the mass among the limbs during locomotion, which is of particular interest for any mass estimation approach on tracks. For instance, the fraction of the weight distributed on the hindlimbs is high when the center of mass of the animal is positioned posteriorly and low when the position of the center of mass is positioned anteriorly. Considering all these influencing factors, mass estimation and reconstruction of movement are possible from recent, as well from fossil tracks. For example, in the case of a 150 million year old sauropod trackway, the mass of the trackmaker was estimated to be about 16 tonnes, which is in good agreement with other mass estimates from body fossils. With these results, this research intends to provide a foundation for future applications of the gait and mass estimation approaches based on tracks, and hopes to inspire others to employ interdisciplinary methods to tetrapod tracks to exploit their, often underestimated, high information content

Climbing and Walking Robots

With the advancement of technology, new exciting approaches enable us to render mobile robotic systems more versatile, robust and cost-efficient. Some researchers combine climbing and walking techniques with a modular approach, a reconfigurable approach, or a swarm approach to realize novel prototypes as flexible mobile robotic platforms featuring all necessary locomotion capabilities. The purpose of this book is to provide an overview of the latest wide-range achievements in climbing and walking robotic technology to researchers, scientists, and engineers throughout the world. Different aspects including control simulation, locomotion realization, methodology, and system integration are presented from the scientific and from the technical point of view. This book consists of two main parts, one dealing with walking robots, the second with climbing robots. The content is also grouped by theoretical research and applicative realization. Every chapter offers a considerable amount of interesting and useful information

Climbing and Walking Robots

Nowadays robotics is one of the most dynamic fields of scientific researches. The shift of robotics researches from manufacturing to services applications is clear. During the last decades interest in studying climbing and walking robots has been increased. This increasing interest has been in many areas that most important ones of them are: mechanics, electronics, medical engineering, cybernetics, controls, and computers. Today’s climbing and walking robots are a combination of manipulative, perceptive, communicative, and cognitive abilities and they are capable of performing many tasks in industrial and non- industrial environments. Surveillance, planetary exploration, emergence rescue operations, reconnaissance, petrochemical applications, construction, entertainment, personal services, intervention in severe environments, transportation, medical and etc are some applications from a very diverse application fields of climbing and walking robots. By great progress in this area of robotics it is anticipated that next generation climbing and walking robots will enhance lives and will change the way the human works, thinks and makes decisions. This book presents the state of the art achievments, recent developments, applications and future challenges of climbing and walking robots. These are presented in 24 chapters by authors throughtot the world The book serves as a reference especially for the researchers who are interested in mobile robots. It also is useful for industrial engineers and graduate students in advanced study

Optimal control of an underactuated bipedal robot

Bipedal robots represent a unique class of control problems that combine many of the most difficult elements of nonlinear control. These robots are typically designed to be mobile and as such have limited energy and actuator authority making efficiency a prime concern. Unlike wheeled robots, legged robots must transition between different equations of motion as legs make and break contact with the ground, aggravating the complexities of hybrid dynamics. Furthermore, small feet and series elastic actuation of joints leads to an underactuated system, causing traditional nonlinear control methods to struggle. This thesis describes and validates a general framework for efficiently controlling systems with the properties most problematic in bipedal robots, i.e., nonlinearity, hybrid dynamics, and underactuation. This process is two-step in that, first, an optimal trajectory is generated using direct collocation trajectory optimization, and second, the feasible trajectory is stabilized using a time varying linear quadratic regulator. We demonstrate this process on a number of toy problems including the triple pendulum on a cart and a reduced order template for a running robot. This approach is then applied to the bipedal robot ATRIAS in simulation in order to achieve efficient, dynamic, and robust locomotion behaviors

Augmented Linear Inverted Pendulum Model for Bipedal Gait Planning

Ph.DDOCTOR OF PHILOSOPH