Aerial Locomotion in Cluttered Environments

Many environments where robots are expected to operate are cluttered with objects, walls, debris, and different horizontal and vertical structures. In this chapter, we present four design features that allow small robots to rapidly and safely move in 3 dimensions through cluttered environments: a perceptual system capable of detecting obstacles in the robot’s surroundings, including the ground, with minimal computation, mass, and energy requirements; a flexible and protective framework capable of withstanding collisions and even using collisions to learn about the properties of the surroundings when light is not available; a mechanism for temporarily perching to vertical structures in order to monitor the environment or communicate with other robots before taking off again; and a self-deployment mechanism for getting in the air and perform repetitive jumps or glided flight. We conclude the chapter by suggesting future avenues for integration of multiple features within the same robotic platform

The EPFL jumpglider: A hybrid jumping and gliding robot with rigid or folding wings

Recent work suggests that wings can be used to prolong the jumps of miniature jumping robots. However, no functional miniature jumping robot has been presented so far that can successfully apply this hybrid locomotion principle. In this publication, we present the development and characterization of the ’EPFL jumpglider’, a miniature robot that can prolong its jumps using steered hybrid jumping and gliding locomotion over varied terrain. For example, it can safely descend from elevated positions such as stairs and buildings and propagate on ground with small jumps. The publication presents a systematic evaluation of three biologically inspired wing folding mechanisms and a rigid wing design. Based on this evaluation, two wing designs are implemented and compared

Energy-based approach to develop soft robots

Soft robotic systems offer advantages against rigid robot systems in applications that involve physical robot-human interactions, unstructured or extreme environments, and manipulating delicate objects. Soft robots can offer inherently safe operation and adapt to unknown geometry of the environment or object. The current soft robot development approach is an empirical approach starting from a type of soft actuation technology, whereas the development of rigid robots can start from a top-level task in a System Engineering framework. The rigid robot developer can select from well-defined components to construct the task-orientated system. Soft robots are relatively novel systems compared with rigid robots and do not have well-defined components due to a wide range of soft actuation technologies. The initial choice of soft actuation technology places constraints on the system to perform the task. Soft robotic systems are not widely used despite the advantages compared to rigid robots. In this thesis, I study an abstraction approach to enable a System Engineering framework to develop soft robotic systems. My research focus is on an energy-based approach that encompasses the multi-domain nature of soft robotic systems. The impact on the final system from the energy transfer characteristics of the initial choice of the soft actuator has not been fully explored in the literature. I study how energy, and rate of energy transfer (power), can describe different components of each type of soft actuation and how the total energy can model the top-level system. This thesis includes (i) a literature review of soft robots; (ii) an abstraction approach based on bond-graph theory applied to soft actuation technologies; (iii) a port-Hamiltonian theory to describe the top-level soft robotic system, and (iv) an experimental application of the approach on a type of soft actuation technology. In summary, I explore how energy and rate of energy transfer can provide the abstraction approach and in time provide the well-defined components necessary for task-orientated design approaches in a System Engineering framework. In particular, I applied the approach to soft pneumatic systems for additional insights relevant to the development of future task-orientated soft robotic systems.EPSRC Doctoral Training Centre in Robotics and Autonomous Systems funding

Experiments in quasi-static manipulation of an elastic rod

The purpose of this dissertation is to experimentally validate a new approach to robotic manipulation of deformable objects. As a case study, it will focus on the manipulation of objects that can be modeled as Kirchhoff elastic rods, for example a metal wire that is held at each end by robotic grippers. Any curve traced by this wire when in static equilibrium can be described as the solution to an optimal control problem with boundary conditions that vary with the position and orientation of each gripper. Recent work has shown that the set of all local solutions to this problem over all possible boundary conditions is a smooth manifold of finite dimension that can be parameterized by a single chart, the coordinates for which have a direct interpretation as forces and torques. These coordinates-in principle-allow the problem of manipulation planning to be formulated as finding a path of the wire through its set of equilibrium configurations, something that was previously thought impossible and that has significant advantages. However, this approach has never before been applied to hardware experiments. We begin by considering a metal wire that is confined to a planar workspace. We derive global coordinates for this wire and characterize the extent to which they accurately describe its shape during robotic manipulation. In particular, we show that differences between predicted and observed manipulation (which can be quite large) derive primarily from small errors in the position and orientation of each robotic gripper. We reduce these differences in two ways. First, we give an algorithm for manipulation planning that locally minimizes sensitivity to errors in gripper placement. Second, we give a feedback control policy (based on force sensor data as well as on position and orientation estimates) that locally minimizes the sum-squared error between planned and observed paths in our global coordinate chart for the wire. We conclude by showing-again, with hardware experiments-that these results extend directly to enable robotic manipulation of a metal wire in a three-dimensional workspace

Bioinspired Jumping Locomotion for Miniature Robotics

In nature, many small animals use jumping locomotion to move in rough terrain. Compared to other modes of ground locomotion, jumping allows an animal to overcome obstacles that are relatively large compared to its size. In this thesis we outline the main design challenges that need to be addressed when building miniature jumping robots. We then present three novel robotic jumpers that solve those challenges and outperform existing similar jumping robots by one order of magnitude with regard to jumping height per size and weight. The robots presented in this thesis, called EPFL jumper v1, EPFL jumper v2 and EPFL jumper v3 have a weight between 7g and 14.3g and are able to jump up to 27 times their own size, with onboard energy and control. This high jumping performance is achieved by using the same mechanical design principles as found in jumping insects such as locusts or fleas. Further, we present a theoretical model which allows an evaluation whether the addition of wings could potentially allow a jumping robot to prolong its jumps. The results from the model and the experiments with a winged jumping robot indicate that for miniature robots, adding wings is not worthwhile when moving on ground. However, when jumping from an elevated starting position, adding wings can lead to longer distances traveled compared to jumping without wings. Moreover, it can reduce the kinetic energy on impact which needs to be absorbed by the robot structure. Based on this conclusion, we developed the EPFL jumpglider, the first miniature jumping and gliding robot that has been presented so far. It has a mass of 16.5g and is able to jump from elevated positions, perform steered gliding flight, land safely and locomote on ground with repetitive jumps1. ______________________________ 1See the collection of the accompanying videos at http://lis.epfl.ch/microglider/moviesAll.zi

The Music Sound

A guide for music: compositions, events, forms, genres, groups, history, industry, instruments, language, live music, musicians, songs, musicology, techniques, terminology , theory, music video. Music is a human activity which involves structured and audible sounds, which is used for artistic or aesthetic, entertainment, or ceremonial purposes. The traditional or classical European aspects of music often listed are those elements given primacy in European-influenced classical music: melody, harmony, rhythm, tone color/timbre, and form. A more comprehensive list is given by stating the aspects of sound: pitch, timbre, loudness, and duration. Common terms used to discuss particular pieces include melody, which is a succession of notes heard as some sort of unit; chord, which is a simultaneity of notes heard as some sort of unit; chord progression, which is a succession of chords (simultaneity succession); harmony, which is the relationship between two or more pitches; counterpoint, which is the simultaneity and organization of different melodies; and rhythm, which is the organization of the durational aspects of music