104 research outputs found

    Discretely Assembled Compliant Mechanisms

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    Bipedal Isotropic Lattice Locomoting Explorer: Robotic Platform for Locomotion and Manipulation of Discrete Lattice Structures and Lightweight Space Structures

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    A robotic platform for traversing and manipulating a modular 3D lattice structure is described. The robot is designed specifically for its tasks within a structured environment, and is simplified in terms of its numbers of degrees of freedom (DOF). This allows for simpler controls and a reduction of mass and cost. Designing the robot relative to the environment in which it operates results in a specific type of robot called a "relative robot". Depending on the task and environment, there can be a number of relative robots. This invention describes a bipedal robot which can locomote across a periodic lattice structure made of building block parts. The robot is able to handle, manipulate, and transport these blocks when there is more than one robot. Based on a general inchworm design, the robot has added functionality while retaining minimal complexity, and can perform numerous maneuvers for increased speed, reach, and placement

    Digital Material Assembly by Passive Means and Modular Isotropic Lattice Extruder System

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    A set of machines and related systems build structures by the additive assembly of discrete parts. These digital material assemblies constrain the constituent parts to a discrete set of possible positions and orientations. In doing so, the structures exhibit many of the properties inherent in digital communication such as error correction, fault tolerance and allow the assembly of precise structures with comparatively imprecise tools. Assembly of discrete cellular lattices by a Modular Isotropic Lattice Extruder System (MILES) is implemented by pulling strings of lattice elements through a forming die that enforces geometry constraints that lock the elements into a rigid structure that can then be pushed against and extruded out of the die as an assembled, loadbearing structure

    Discrete Assemblers Utilizing Conventional Motion Systems

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    An alternative to additive manufacturing is disclosed, introducing an end-to-end workflow in which discrete building blocks are reversibly joined to produce assemblies called digital materials. Described is the design of the bulk-material building blocks and the devices that are assembled from them. Detailed is the design and implementation of an automated assembler, which takes advantage of the digital material structure to avoid positioning errors within a large tolerance. To generate assembly sequences, a novel CAD/CAM workflow is described for designing, simulating, and assembling digital materials. The structures assembled using this process have been evaluated, showing that the joints perform well under varying conditions and that the assembled structures are functionally precise

    Convex modeling with priors

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2006.Includes bibliographical references (leaves 159-169).As the study of complex interconnected networks becomes widespread across disciplines, modeling the large-scale behavior of these systems becomes both increasingly important and increasingly difficult. In particular, it is of tantamount importance to utilize available prior information about the system's structure when building data-driven models of complex behavior. This thesis provides a framework for building models that incorporate domain specific knowledge and glean information from unlabeled data points. I present a methodology to augment standard methods in statistical regression with priors. These priors might include how the output series should behave or the specifics of the functional form relating inputs to outputs. My approach is optimization driven: by formulating a concise set of goals and constraints, approximate models may be systematically derived. The resulting approximations are convex and thus have only global minima and can be solved efficiently. The functional relationships amongst data are given as sums of nonlinear kernels that are expressive enough to approximate any mapping. Depending on the specifics of the prior, different estimation algorithms can be derived, and relationships between various types of data can be discovered using surprisingly few examples.(cont.) The utility of this approach is demonstrated through three exemplary embodiments. When the output is constrained to be discrete, a powerful set of algorithms for semi-supervised classification and segmentation result. When the output is constrained to follow Markovian dynamics, techniques for nonlinear dimensionality reduction and system identification are derived. Finally, when the output is constrained to be zero on a given set and non-zero everywhere else, a new algorithm for learning latent constraints in high-dimensional data is recovered. I apply the algorithms derived from this framework to a varied set of domains. The dissertation provides a new interpretation of the so-called Spectral Clustering algorithms for data segmentation and suggests how they may be improved. I demonstrate the tasks of tracking RFID tags from signal strength measurements, recovering the pose of rigid objects, deformable bodies, and articulated bodies from video sequences. Lastly, I discuss empirical methods to detect conserved quantities and learn constraints defining data sets.by Benjamin Recht.Ph.D

    The Milli-Motein: A self-folding chain of programmable matter with a one centimeter module pitch

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    The Milli-Motein (Millimeter-Scale Motorized Protein) is ca chain of programmable matter with a 1 cm pitch. It can fold itself into digitized approximations of arbitrary three-dimensional shapes. The small size of the Milli-Motein segments is enabled by the use of our new electropermanent wobble stepper motors, described in this paper, and by a highly integrated electronic and mechanical design. The chain is an interlocked series of connected motor rotors and stators, wrapped with a continuous flex circuit to provide communications, control, and power transmission capabilities. The Milli-Motein uses off-the-shelf electronic components and fasteners, and custom parts fabricated by conventional and electric discharge machining, assembled with screws, glue, and solder using tweezers under a microscope. We perform shape reconfiguration experiments using a four-segment Milli-Motein. It can switch from a straight line to a prescribed shape in 5 seconds, consuming 2.6 W power during reconfiguration. It can hold its shape indefinitely without power. During reconfiguration, a segment can lift the weight of one but not two segments as a horizontal cantilever.United States. Defense Advanced Research Projects Agency. Programmable Matter ProgramUnited States. Defense Advanced Research Projects Agency. Maximum Mobility and Manipulation (M3) ProgramUnited States. Army Research Office (Grant W911NF-08-1-0254)United States. Army Research Office (Grant W911NF-11-1-0096)Massachusetts Institute of Technology. Center for Bits and Atom

    Reconfigurable Asynchronous Logic Automata (RALA)

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    Computer science has served to insulate programs and programmers from knowledge of the underlying mechanisms used to manipulate information, however this fiction is increasingly hard to maintain as computing devices decrease in size and systems increase in complexity. Manifestations of these limits appearing in computers include scaling issues in interconnect, dissipation, and coding. Reconfigurable Asynchronous Logic Automata (RALA) is an alternative formulation of computation that seeks to align logical and physical descriptions by exposing rather than hiding this underlying reality. Instead of physical units being represented in computer programs only as abstract symbols, RALA is based on a lattice of cells that asynchronously pass state tokens corresponding to physical resources. We introduce the design of RALA, review its relationships to its many progenitors, and discuss its benefits, implementation, programming, and extensions.National Science Foundation (U.S.) Center for Bits and AtomsUnited States. Army Research Office (Grant number W911NF-08-1-0254)United States. Army Research Office (Grant number W911NF-09-1-0542
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