Development of a robotic torque application gripper for automated furniture assembly

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 39).This thesis describes the redesign of a robotic claw end-effector originally built for the MIT class 6.142. The claw was designed in order to assist an autonomous furniture assembly robotic project by spinning . The project used KUKA youbots in order to assemble IKEA Lak tables. The first generation of the claw was designed and built very quickly out of laser-cut materials and is described briefly. This final version was designed to be a high-quality machine, with an emphasis placed on the weight and form, and performance. After a brief introduction, my design philosophy that guided the process is briefly described. Next the specific details of the design are described. The design and FEA analysis of the frame in order to optimize weight and strength are discussed, as well as the design of the fluid damping device. The power train design and analysis is then briefly described with an emphasis on efficiency and evaluating the usefulness of the approach that I took. The next area of concern is a characterization of the kinematics of the grasping elastic encirclement members that grasp the object, followed by a discussion of the lessons learned.by John Romanishin.S.B

IkeaBot: An autonomous multi-robot coordinated furniture assembly system

We present an automated assembly system that directs the actions of a team of heterogeneous robots in the completion of an assembly task. From an initial user-supplied geometric specification, the system applies reasoning about the geometry of individual parts in order to deduce how they fit together. The task is then automatically transformed to a symbolic description of the assembly-a sort of blueprint. A symbolic planner generates an assembly sequence that can be executed by a team of collaborating robots. Each robot fulfills one of two roles: parts delivery or parts assembly. The latter are equipped with specialized tools to aid in the assembly process. Additionally, the robots engage in coordinated co-manipulation of large, heavy assemblies. We provide details of an example furniture kit assembled by the system.Boeing Compan

Three dimensional modular self-reconfigurable robots

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.Cataloged from PDF version of thesis.Includes bibliographical references (pages 79-85).This thesis details the development of the 3D M-Blocks modular robot system. Modular self-reconfigurable robots (MSRR) are robotic systems which contain many modules that can form and break connections with other modules, and move on a lattice of other modules in order to form different configurations. The 3D M-Blocks is a new system which attempts to investigate the feasibility of using inertial actuation from reaction wheels in order to pivot modules on a 3D lattice. Many existing systems described in related literature are able to exhibit reconfiguration, but usually these systems are only able to do so under limited circumstances, e.g. they only work in 2 dimensions or in the absence of gravity. The 3D M-blocks is one of the only systems which is able to move modules according to a general lattice movement model in full three dimensional space under the effects of gravity. The 3D M-Blocks rotate relative to one another through the use of temporary magnetic hinges, and form bonds with each other through the use of permanent magnets. Rules describing the movement framework under which the modules move, called the Pivoting Cube Model (PCM), are discussed in depth. Each 50 mm 3D M-Block module contains all of the components necessary to operate autonomously and communicate over WiFi. Each module contains a cubic frame which supports the rotation and magnetic bonding with neighbors, and which holds the core robot assembly, including an inertial actuator and electronics. The inertial actuator is a reaction wheel with a fast acting band brake which is used to generate pulses of torque sufficient to induce lattice pivoting motions. Experiments characterizing the performance of the inertial actuator and the magnetic hinges are described. Additionally, experiments validating individual lattice movements demonstrate the feasibility of this approach to general 3D reconfiguration. Experiments describing modules modules individually and as groups are also presented.by John William Romanishin.S.M

Detection of Two Binary Trans-Neptunian Objects, 1997 CQ29 and 2000 CF105, with the Hubble Space Telescope

Images of the trans-Neptunian objects 1997 CQ29 and 2000 CF105 obtained with the Hubble Space Telescope’s WFPC2 camera show them to be binary. The two components of 1997 CQ29 were separated in our images by 0.20±0.03 arsec in November 2001 and by 0.33±0.01 arcsec in June/July 2002. The corresponding minimum physical distances are 6100 km and 10,200 km. The companion to 2000 CF105 was 0.78±0.03 arcsec from the primary, at least 23,400 km. Six other objects in the trans-Neptunian region, including Pluto and its moon Charon, are known to be binaries; 1997 CQ29 and 2000 CF105 are the seventh and eighth known pair. Binarity appears to be a not-uncommon characteristic in this region of the solar system, with detectable companions present in 4±2 % of the objects we have examined. Subject headings: Kuiper Belt, Oort cloud – 3 – 1

Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. VIII. An intensive HST, IUE, and ground-based study of NGC 5548

We present the data and initial results from a combined HST/IUE/ground-based spectroscopic monitoring campaign on the Seyfert I galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-1989. IUE spectra were obtained once every 2 days for a period of 74 days beginning on 1993 March 14. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both eco imaging and aperture photometry), are reported for the period 1992 October-1993 September, although many of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution we describe the acquisition and reduction of ali of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies. During the HST portion of the monitoring campaign, the 1350 Å continuum flux is found to have varied by nearly a factor of 2. In other wave bands, the continuum shows nearly identical behavior, except that the amplitude of variability is larger at shorter wavelengths, and the continuum light curves appear to show more short­ timescale variability at shorter wavelengths. The broad emission lines also vary in flux, with amplitudes that are slightly smaller than the UV continuum variations and with a small time delay relative to the UV continuum. On the basis of simple time-series analysis of the UV and optical continuum and emission-line light curves, we find (1) that the ultraviolet and optical continuum variations are virtually simultaneous, with any lag between the 1350 Å continuum and the 5100 Å continuum amounting to less than about 1 day; (2) that the variations in the highest ionization lines observed, He II λ1640 and N v λ1240, lag behind the continuum variations by somewhat less than 2 days; and (3) that the velocity field of the C IV-emitting region is not dominated by radial motion. The results on the C IV velocity field are pretiminary and quite uncertain, but there are some weak indications that the emission-line wings (|Δv|≥ 3000 km s-ˡ) respond to continuum variations slightly more rapidly than does the core. The optical observations show that the variations in the broad Hβ line flux follow the continuum variations with time lag of around 2 weeks, about twice the lag for Lyα and C IV, as in our previous monitoring campaign on this same galaxy. However, the lags measured for Lyα, C IV, and Hβ are each slightly smaller than previous determmations. We confirm two trends reported eartier, namely, (1) that the UV /optical continuum becomes "harder" as it gets brighter and (2) that the highest ionization emission lines have the shortest lags, thus indicating radial ionization stratification of a broad-line region that spans over an order of magnitude range in radius

Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. VIII. An intensive HST, IUE, and ground-based study of NGC 5548

We present the data and initial results from a combined HST/IUE/ground-based spectroscopic monitoring campaign on the Seyfert I galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-1989. IUE spectra were obtained once every 2 days for a period of 74 days beginning on 1993 March 14. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both eco imaging and aperture photometry), are reported for the period 1992 October-1993 September, although many of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution we describe the acquisition and reduction of ali of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies. During the HST portion of the monitoring campaign, the 1350 Å continuum flux is found to have varied by nearly a factor of 2. In other wave bands, the continuum shows nearly identical behavior, except that the amplitude of variability is larger at shorter wavelengths, and the continuum light curves appear to show more short­ timescale variability at shorter wavelengths. The broad emission lines also vary in flux, with amplitudes that are slightly smaller than the UV continuum variations and with a small time delay relative to the UV continuum. On the basis of simple time-series analysis of the UV and optical continuum and emission-line light curves, we find (1) that the ultraviolet and optical continuum variations are virtually simultaneous, with any lag between the 1350 Å continuum and the 5100 Å continuum amounting to less than about 1 day; (2) that the variations in the highest ionization lines observed, He II λ1640 and N v λ1240, lag behind the continuum variations by somewhat less than 2 days; and (3) that the velocity field of the C IV-emitting region is not dominated by radial motion. The results on the C IV velocity field are pretiminary and quite uncertain, but there are some weak indications that the emission-line wings (|Δv|≥ 3000 km s-ˡ) respond to continuum variations slightly more rapidly than does the core. The optical observations show that the variations in the broad Hβ line flux follow the continuum variations with time lag of around 2 weeks, about twice the lag for Lyα and C IV, as in our previous monitoring campaign on this same galaxy. However, the lags measured for Lyα, C IV, and Hβ are each slightly smaller than previous determmations. We confirm two trends reported eartier, namely, (1) that the UV /optical continuum becomes "harder" as it gets brighter and (2) that the highest ionization emission lines have the shortest lags, thus indicating radial ionization stratification of a broad-line region that spans over an order of magnitude range in radius