Jamming problems and the effects of compliance in dual peg-hole disassembly

Disassembly is a crucial step in remanufacturingand is currently mainly performed by humans.Automating disassembly can reduce labour costs andmake remanufacturing more economically attractive.This paper focuses on identifying and characterizing acommon disassembly task, dual peg-hole disassembly,with the aim of building a robotic disassembly systemfor this task. We enumerate the possible contact statesand their geometric conditions during the extractionof two studs in a dual peg-hole. This paper focuses onjamming in the extraction and conducts geometricaland quasi-static analyses to determine the boundaryconditions of jamming. Based on the analyses, thispaper also investigates the role of active compliance asa solution to avoid jamming. We also simulate criticalvariables and examine key parameters such as thedegree of compliance, the location of the compliancecentre and initial position errors. Finally, we conductexperimental studies on dual peg-hole extraction withdifferent compliance centres obtained using active compliance

Automated Assembly Using Feature Localization

Automated assembly of mechanical devices is studies by researching methods of operating assembly equipment in a variable manner; that is, systems which may be configured to perform many different assembly operations are studied. The general parts assembly operation involves the removal of alignment errors within some tolerance and without damaging the parts. Two methods for eliminating alignment errors are discussed: a priori suppression and measurement and removal. Both methods are studied with the more novel measurement and removal technique being studied in greater detail. During the study of this technique, a fast and accurate six degree-of-freedom position sensor based on a light-stripe vision technique was developed. Specifications for the sensor were derived from an assembly-system error analysis. Studies on extracting accurate information from the sensor by optimally reducing redundant information, filtering quantization noise, and careful calibration procedures were performed. Prototype assembly systems for both error elimination techniques were implemented and used to assemble several products. The assembly system based on the a priori suppression technique uses a number of mechanical assembly tools and software systems which extend the capabilities of industrial robots. The need for the tools was determined through an assembly task analysis of several consumer and automotive products. The assembly system based on the measurement and removal technique used the six degree-of-freedom position sensor to measure part misalignments. Robot commands for aligning the parts were automatically calculated based on the sensor data and executed

Encoded hydrogel microparticles for high-throughput molecular diagnostics and personalized medicine

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 141-161).The ability to accurately detect and quantify biological molecules in complex mixtures is crucial in basic research as well as in clinical settings. Advancements in genetic analysis, molecular diagnostics, and patient-tailored medicine require robust detection technologies that can obtain high-density information from a range of physiological samples in a rapid and cost-effective manner. Compared to conventional microarrays and methods based on polymerase chain reaction (PCR), suspension (particle-based) arrays offer several advantages in the multiplexed detection of biomolecules, including higher rates of sample processing, reduced consumption of sample and reagent, and rapid probe-set modification for customizable assays. This thesis expands the utility of a novel hydrogel-based microparticle array through (1) the creation of a microfluidic, flow-through fluorescence scanner for high-throughput particle analysis, (2) the development of a suite of techniques for the highly sensitive and specific detection of microRNA (miRNA) biomarkers, and (3) the investigation of new methods for directly measuring biomolecules at the single-cell level. Graphically-encoded hydrogel microparticles synthesized from non-fouling, bioinert poly(ethylene glycol) (PEG) and functionalized with biomolecule probes offer great promise in the development of high-performance, multiplexed bioassays. To extend this platform to applications in high-throughput analysis, particle design was optimized to ensure mechanical stability in high-velocity flow systems, and a single-color microfluidic scanner was constructed for the rapid fluorescence interrogation of each particle's spatially-segregated "code" and "probe" regions. The detection advantages of three-dimensional, probe-laden hydrogel scaffolds and the operational efficiencies of suspension array technology were then leveraged for the rapid multiplexed expression profiling of miRNA. The graphical encoding method and ligationbased labeling scheme implemented here allowed for scalable multiplexing with a simple workflow and an unprecedented combination of sensitivity, flexibility, and throughput. Through the rolling circle amplification of a labeling oligonucleotide, it was possible to further enhance the system's sensitivity and resolve single-molecule miRNA binding events on particle surfaces, enabling the first direct detection of low-abundance miRNA in human serum without the need for RNA extraction or target amplification. Finally, by arraying cells and gel particles in polydimethylsiloxane (PDMS) microwells, it was possible to dramatically improve the particles' target capture efficiency and thereby move closer to a regime in which miRNAs and other biological molecules may be directly detected without target amplification from single cells.by Stephen Clifford Chapin.Ph.D

Proceedings of the NASA Conference on Space Telerobotics, volume 4

Papers presented at the NASA Conference on Space Telerobotics are compiled. The theme of the conference was man-machine collaboration in space. The conference provided a forum for researchers and engineers to exchange ideas on the research and development required for the application of telerobotic technology to the space systems planned for the 1990's and beyond. Volume 4 contains papers related to the following subject areas: manipulator control; telemanipulation; flight experiments (systems and simulators); sensor-based planning; robot kinematics, dynamics, and control; robot task planning and assembly; and research activities at the NASA Langley Research Center

Annals of Scientific Society for Assembly, Handling and Industrial Robotics 2021

This Open Access proceedings presents a good overview of the current research landscape of assembly, handling and industrial robotics. The objective of MHI Colloquium is the successful networking at both academic and management level. Thereby, the colloquium focuses an academic exchange at a high level in order to distribute the obtained research results, to determine synergy effects and trends, to connect the actors in person and in conclusion, to strengthen the research field as well as the MHI community. In addition, there is the possibility to become acquatined with the organizing institute. Primary audience is formed by members of the scientific society for assembly, handling and industrial robotics (WGMHI)