Coordinated locomotion between robots separated by a surface

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 69-70).This SM thesis presents the design, modeling, and experimental verification of a novel, programmable connection mechanism for robots separated by a-surface. The connector uses electropermanent magnets (EPMs) [5] to establish a continuum of clamping force between the robots, enabling the motion of one robot to slave the other during a variety of maneuvers. The author designs a novel, solid-state EPM arrangement capable of generating up to an estimated 890N of clamping force under environmental load conditions. A relationship between geometric and environmental variables and connection assembly performance is first modeled and subsequently experimentally characterized. By implementing these connectors in a custom manufactured pair of assembly robots, the author demonstrates the connection assembly and magnetizing hardware can be compactly fit within a tetherless robot application. This mechanism provides a repeatable, easily-automated alternative to robotic systems that depend on mechanic means to regulate clamping force [6].by Andrew D. Marchese.S.M

Electropermanent Magnet Study

Bakalářská práce pojednává o problematice elektropermanentního magnetu (EPM). Obsahuje teoretickou, výpočetní i experimentální část. Kapitoly teoretické části vysvětlují princip EPM, popisují jeho výhody a nevýhody, a věnují se možným použitím EPM v praxi. Odvození matematicko-fyzikálních vztahů pro návrh EPM, návrh konkrétního zařízení s funkcí EPM a simulace ověřující teoretické principy jeho provozních stavů jsou obsaženy ve výpočetní části. Pro simulaci bylo zvoleno prostředí ANSYS Maxwell. V experimentální části jsou pak uvedeny a diskutovány výsledky měření, které dokládají správnost návrhu, spolu s porovnáním mezi teoretickým výpočtem, simulací a praktickým experimentem.This thesis focuses on the principle of operation, description and experimental verification of the electropermanent magnet (EPM), which is a solid-state device whose external magnetic flux can be stably switched on and off by a discrete electrical pulse. The thesis is divided into the theoretical, computational and experimental parts. The theoretical part describes the EPM principle of operation and lists its advantages, disadvantages and application potentials. Next, a mathematical-physical model of the EPM device is derived in the computational part. The computational part also contains the specifications for the design of a real EPM device and simulations, carried out in the realistic simulator ANSYS Maxwell, that verify the EPM functionality and support the derived theoretical relations. Finally, the experimental part reports on the experimental evaluation with a real EPM device, made according to the presented specifications, together with the description and comparison to the theoretical and simulated results

非線形弾性要素による内部力補償に基づく無段階変位–力変換機構の創生 ― 微小操作力で強大な磁気力・把持力・制動力・張力を制御可能とするロボット要素 ―

Tohoku University博士（情報科学）thesi

Electropermanent magnetic connectors and actuators : devices and their application in programmable matter

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 199-206).Programmable matter is a digital material having computation, sensing, and actuation capabilities as continuous properties active over its whole extent. To make programmable matter economical to fabricate, we want to use electromagnetic direct drive, rather than clockwork, to actuate the particles. Previous attempts to fabricate small scale (below one centimeter) robotic systems with electromagnetic direct-drive have typically run into problems with insufficient force or torque, excessive power consumption and heat generation (for magnetic-drive systems), or high-voltage requirements, humidity sensitivity, and air breakdown. (for electrostatic-drive systems) The electropermanent magnet is a solid-state device whose external magnetic flux can be stably switched on and off by a discrete electrical pulse. Electropermanent magnets can provide low-power connection and actuation for programmable matter and other small-scale robotic systems. The first chapter covers the electropermanent magnet, its physics, scaling, fabrication, and our experimental device performance data. The second introduces the idea of electropermanent actuators, covers their fundamental limits and scaling, and shows prototype devices and performance measurements. The third chapter describes the smart pebbles system, which consists of 12-mm cubes that can form shapes by stochastic self-assembly and self-disassembly. The fourth chapter describes the millibot, a continuous chain of programmable matter which forms shapes by folding.by Ara Nerses Knaian.Ph.D

Design of novel adaptive magnetic adhesion mechanism for climbing robots in ferric structures

The work presented in this thesis proposes a novel adaptive magnetic adhesion mechanism that can be implemented in most locomotion mechanisms employed in climbing robots for ferric structures. This novel mechanism has the capability to switch OFF and ON its magnetic adhesion with minimal power consumption, and remain at either state after the excitation is removed. Furthermore, the proposed adhesion mechanism has the ability to adapt the strength of the adhesive force to a desired magnitude. These capabilities make the proposed adhesion mechanism a potential solution in the field of wall climbing robots. The novel contributions of the proposed mechanism include the switching of the adhesive force, selectivity of the adhesive force magnitude; determination of the parameters that have an impact in the final adhesive force. Finally, a final prototype is constructed with customised components and it is subject to a set of simulations and experiments to validate its performance

Shape formation by self-disassembly in programmable matter systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 225-236).Programmable matter systems are composed of small, intelligent modules able to form a variety of macroscale objects with specific material properties in response to external commands or stimuli. While many programmable matter systems have been proposed in fiction, (Barbapapa, Changelings from Star Trek, the Terminator, and Transformers), and academia, a lack of suitable hardware and accompanying algorithms prevents their full realization. With this thesis research, we aim to create a system of miniature modules that can form arbitrary structures on demand. We develop autonomous 12mm cubic modules capable of bonding to, and communicating with, four of their immediate neighbors. These modules are among the smallest autonomous modular robots capable of sensing, communication, computation, and actuation. The modules employ unique electropermanent magnet connectors. The four connectors in each module enable the modules to communicate and share power with their nearest neighbors. These solid-state connectors are strong enough for a single inter-module connection to support the weight of 80 other modules. The connectors only consume power when switching on or off; they have no static power consumption. We implement a number of low-level communication and control algorithms which manage information transfer between neighboring modules. These algorithms ensure that messages are delivered reliably despite challenging conditions. They monitor the state of all communication links and are able to reroute messages around broken communication links to ensure that they reach their intended destinations. In order to accomplish our long-standing goal of programmatic shape formation, we also develop a suite of provably-correct distributed algorithms that allow complex shape formation. The distributed duplication algorithm that we present allows the system to duplicate any passive object that is submerged in a collection of programmable matter modules. The algorithm runs on the processors inside the modules and requires no external intervention. It requires 0(1) storage and O(n) inter-module messages per module, where n is the number of modules in the system. The algorithm can both magnify and produce multiple copies of the submerged object. A programmable matter system is a large network of autonomous processors, so these algorithms have applicability in a variety of routing, sensor network, and distributed computing applications. While our hardware system provides a 50-module test-bed for the algorithms, we show, by using a unique simulator, that the algorithms are capable of operating in much larger environments. Finally, we perform hundreds of experiments using both the simulator and hardware to show how the algorithms and hardware operate in practice.by Kyle William Gilpin.Ph.D

Sensing and actuation for the design of upper limb prosthetics

The objective of this thesis has been to improve upper limb prosthetics. With this aim in mind, and based on reported user needs, we targeted two main aspects of contemporary active prosthetics: sensing and actuation. The restoration of proprioceptive capabilities through the artificial limb is vital for their intuitive and precise control. In order to capture the prosthetics position, we designed extremely soft microfluidic sensors using conductive liquids such as eutectic Gallium Indium (eGaIn) or Room Temperature Ionic Liquid (RTIL) embedded in soft elastomers. These sensors were used first to sense unidirectional strain, then normal force through Electrical Impedance Tomography (EIT) in a soft microfluidic skin, and were finally embedded in a soft artificial skin that was used to measure the human hand motion. Conventional electromagnetic actuators are poorly suited for prosthetic actuation. Grasping tasks typically require large torque at low speeds whereas conventional actuators are designed to be efficient at high rotational speeds. In consequence, we designed the "Programmable Permanent Magnet" (PPM) actuator. This unique actuator, based on the magnetization of permanent magnets by current pulses, is able to maintain a large torque at no speed and for no energetic cost. This actuator is especially suited for tasks such as grasping or walking and represents a new type of electromagnetic actuator that will enable efficient low speed high torque efficient actuation for robotic and prosthetic applications

Process Development for the Fabrication of Spheroidal Microdevice Packages Utilizing MEMS Technologies

Sub-mm3 spherical microrobots are being researched as a path towards reconfigurable wireless networks and programmable matter. The microrobot design requires a spheroidal microdevice package compatible with solar energy collection, wireless sensing, and electrostatic actuation mechanisms to be developed. Throughout this research, a variety of MEMS fabrication techniques were evaluated with regards to their applicability to the packaging process. SF6-based plasma was determined to be a preferable alternative to wet HNA etching when producing repeatable bulk isotropic etches in silicon. The effect of silicon crystal orientation on etch variance and anisotropy was also investigated. HNA polishing was demonstrated as an effective method of reducing undercutting, surface roughness, and anisotropy. MatLab image processing routines were developed and incorporated into etch analysis, providing an efficient method of data collection. A method of performing sophisticated wafer alignment and photolithography processes by leveraging existing cleanroom devices was proposed. This research established a path forward for an advanced packaging scheme designed to move microelectronics packages away from the planar circuit board configurations of the past and into the autonomous architectures of the future. The proposed design is applicable to a wide variety of microelectronics applications while meeting the requirements of the sub-mm3 spherical microrobot system

Aerial Robotics for Inspection and Maintenance

Aerial robots with perception, navigation, and manipulation capabilities are extending the range of applications of drones, allowing the integration of different sensor devices and robotic manipulators to perform inspection and maintenance operations on infrastructures such as power lines, bridges, viaducts, or walls, involving typically physical interactions on flight. New research and technological challenges arise from applications demanding the benefits of aerial robots, particularly in outdoor environments. This book collects eleven papers from different research groups from Spain, Croatia, Italy, Japan, the USA, the Netherlands, and Denmark, focused on the design, development, and experimental validation of methods and technologies for inspection and maintenance using aerial robots