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All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

CSI computer system/remote interface unit acceptance test results

The validation tests conducted on the Control/Structures Interaction (CSI) Computer System (CCS)/Remote Interface Unit (RIU) is discussed. The CCS/RIU consists of a commercially available, Langley Research Center (LaRC) programmed, space flight qualified computer and a flight data acquisition and filtering computer, developed at LaRC. The tests were performed in the Space Structures Research Laboratory (SSRL) and included open loop excitation, closed loop control, safing, RIU digital filtering, and RIU stand alone testing with the CSI Evolutionary Model (CEM) Phase-0 testbed. The test results indicated that the CCS/RIU system is comparable to ground based systems in performing real-time control-structure experiments.

Sparks, Dean W., Jr.↗
NASA NTRS1992

Design, analysis, and testing of the Phase 1 CSI Evolutionary Model erectable truss

This report addressed the design, analysis, and testing of the erectable truss structure for the Phase 1 CSI Evolutionary Model (CEM) testbed. The Phase 1 CEM testbed is the second testbed to form part of an ongoing program of focused research at NASA/LaRC in the development of Controls-Structures Integration (CSI) technology. The Phase 1 CEM contains the same overall geometry, weight, and sensor locations as the Phase 0 CEM, but is based in an integrated controller and structure design, whereby both structure and controller design variables are sized simultaneously. The Phase 1 CEM design features seven truss sections composed of struts with tailored mass and stiffness properties. A common erectable joint is used and the strut stiffness is tailored by varying the cross-sectional area. To characterize the structure, static tests were conducted on individual struts and 10-bay truss assemblies. Dynamic tests were conducted on 10-bay truss assemblies as well as the fully-assembled CEM truss. The results indicate that the static and dynamic properties of the structure are predictable, well-characterized, and within the performance requirements established during the Phase 1 CEM integrated controller/structure design analysis.

Gronet, M. J.↗
NASA NTRS1993

The Mini-Mast CSI testbed: Lessons learned

The Mini-Mast testbed was one of the first large scale Controls-Structure-Interaction (CSI) systems used to evaluate state-of-the-art methodology in flexible structure control. Now that all the testing at Langley Research Center has been completed, a look back is warranted to evaluate the program. This paper describes some of the experiences and technology development studies by NASA, university, and industry investigators. Lessons learned are presented from three categories: the testbed development, control methods, and the operation of a guest investigator program. It is shown how structural safety margins provided a realistic environment to simulate on-orbit CSI research, even though they also reduced the research flexibility afforded to investigators. The limited dynamic coupling between the bending and torsion modes of the cantilevered test article resulted in highly successful SISO and MIMO controllers. However, until accurate models were obtained for the torque wheel actuators, sensors, filters, and the structure itself, most controllers were unstable. Controls research from this testbed should be applicable to cantilevered appendages of future large space structures.

Tanner, Sharon E.↗
NASA NTRS1993

CSI Flight Computer System and experimental test results

This paper describes the CSI Computer System (CCS) and the experimental tests performed to validate its functionality. This system is comprised of two major components: the space flight qualified Excitation and Damping Subsystem (EDS) which performs controls calculations; and the Remote Interface Unit (RIU) which is used for data acquisition, transmission, and filtering. The flight-like RIU is the interface between the EDS and the sensors and actuators positioned on the particular structure under control. The EDS and RIU communicate over the MIL-STD-1553B, a space flight qualified bus. To test the CCS under realistic conditions, it was connected to the Phase-0 CSI Evolutionary Model (CEM) at NASA Langley Research Center. The following schematic shows how the CCS is connected to the CEM. Various tests were performed which validated the ability of the system to perform control/structures experiments.

Sparks, Dean W., Jr.↗
NASA NTRS1993

CSI flight experiment projects of the Naval Research Laboratory

The Naval Research Laboratory (NRL) is involved in an active program of CSI flight experiments. The first CSI flight experiment of the Naval Research Laboratory, the Low Power Atmospheric Compensation Experiment (LACE) dynamics experiment, has successfully measured vibrations of an orbiting satellite with a ground-based laser radar. The observations, made on January 7, 8 and 10, 1991, represent the first ever measurements of this type. In the tests, a narrowband heterodyne CO2 laser radar, operating at a wavelength of 10.6 microns, detected vibration induced differential-Doppler signatures of the LACE satellite. Power spectral densities of forced oscillations and modal frequencies and damping rates of free-damped vibrations were obtained and compared with finite element structural models of the LACE system. Another manifested flight experiment is the Advanced Controls Technology Experiment (ACTEX) designed to demonstrate active and passive damping with piezo-electric (PZT) sensors and actuators. This experiment was developed under the management of the Air Force Phillips Laboratory with integration of the experiment at NRL. It is to ride as a secondary, or 'piggyback,' experiment on a future Navy satellite.

Fisher, Shalom↗
NASA NTRS1992

The NASA-LaRC Controls-Structures Interaction (CSI) technology program

One of the main difficulties encountered in the design and implementation of control systems for spacecraft is the interaction between the control system and the flexibility of the vehicle. This difficulty has resulted in problems for a multitude of spacecraft including the earliest U.S. spacecraft, Explorer I; the Orbiting Geophysical Observatory III; Mariner 10; Galileo; and the Hubble Telescope. Recognizing the importance of the issue, NASA has an ongoing Controls-Structures Interaction (CSI) technology program to develop the methodology to design optimally and simultaneously both the control system and the structure. The CSI program is a multicenter program involving research teams from NASA's Langley Research Center (LaRC), Jet Propulsion Laboratory (JPL), and Marshall Space Flight Center (MSFC). JPL's area of interest is in optics-class vehicles and MSFC's in astrophysics vehicles. The aim of this paper is to explain the ongoing activities at LaRC, which are of a theoretical, ground test, and flight test nature, with focus on applications to spacecraft with multiple experiment-pointing mounts, large space radiometers, Space Station Freedom (SSF), and the Space Shuttle Remote Manipulator System (RMS).

Anderson, Willard W.↗
NASA NTRS1991

JPL control-structure interaction technology: Micro-precision CSI

The NASA Control-Structure Interaction (CSI) Program is described in outline and graphic form. Particular emphasis is given to the activities of the Jet Propulsion Lab. The goals of the program are (1) controlled structure performance enhancement, (2) controlled structure unified methods for design/analysis, and (3) ground validation methods for CSI flight systems.

Laskin, Robert A.↗
NASA NTRS1989

Experiment and simulation for CSI: What are the missing links?

Viewgraphs on experiment and simulation for control structure interaction (CSI) are presented. Topics covered include: control structure interaction; typical control/structure interaction system; CSI problem classification; actuator/sensor models; modeling uncertainty; noise models; real-time computations; and discrete versus continuous.

Belvin, W. Keith↗
NASA NTRS1994

Development of the CSI phase-3 evolutionary model testbed

This report documents the development effort for the reconfiguration of the Controls-Structures Integration (CSI) Evolutionary Model (CEM) Phase-2 testbed into the CEM Phase-3 configuration. This step responds to the need to develop and test CSI technologies associated with typical planned earth science and remote sensing platforms. The primary objective of the CEM Phase-3 ground testbed is to simulate the overall on-orbit dynamic behavior of the EOS AM-1 spacecraft. Key elements of the objective include approximating the low-frequency appendage dynamic interaction of EOS AM-1, allowing for the changeout of components, and simulating the free-free on-orbit environment using an advanced suspension system. The fundamentals of appendage dynamic interaction are reviewed. A new version of the multiple scaling method is used to design the testbed to have the full-scale geometry and dynamics of the EOS AM-1 spacecraft, but at one-tenth the weight. The testbed design is discussed, along with the testing of the solar array, high gain antenna, and strut components. Analytical performance comparisons show that the CEM Phase-3 testbed simulates the EOS AM-1 spacecraft with good fidelity for the important parameters of interest.

Gronet, M. J.↗
DOE OSTI2020

CsI calorimeter for the J-PARC KOTO experiment

An electromagnetic calorimeter made of undoped CsI crystals is used in the J-PARC KOTO experiment to search for new physics beyond the standard model with the KL → π 0 νν¯ decay. The calorimeter is designed to operate in vacuum of 0.1 Pa and in a high-rate environment where the counting rate due to KL decays is O(100) kHz. A special method to calibrate the calorimeter during the data taking without using a tracking system for charged particles is reported. The energy, position, and timing resolutions of the calorimeter were evaluated in several beam tests, and the resolutions satisfy the required performance. Finally, the energy resolution with the total energy E is 0.66 ⊕ 1.81/ √ E[GeV]% in the inner region of the calorimeter.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Materials Data on CsI by Materials Project

CsI is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Cs1+ is bonded to six equivalent I1- atoms to form a mixture of edge and corner-sharing CsI6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Cs–I bond lengths are 3.93 Å. I1- is bonded to six equivalent Cs1+ atoms to form a mixture of edge and corner-sharing ICs6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsY by Materials Project

CsY is alpha Samarium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Cs is bonded to six equivalent Cs and six equivalent Y atoms to form CsCs6Y6 cuboctahedra that share corners with eighteen equivalent CsCs6Y6 cuboctahedra, edges with six equivalent CsCs6Y6 cuboctahedra, edges with twelve equivalent YCs6Y6 cuboctahedra, faces with eight equivalent CsCs6Y6 cuboctahedra, and faces with twelve equivalent YCs6Y6 cuboctahedra. All Cs–Cs bond lengths are 3.84 Å. All Cs–Y bond lengths are 4.36 Å. Y is bonded to six equivalent Cs and six equivalent Y atoms to form YCs6Y6 cuboctahedra that share corners with eighteen equivalent YCs6Y6 cuboctahedra, edges with six equivalent YCs6Y6 cuboctahedra, edges with twelve equivalent CsCs6Y6 cuboctahedra, faces with eight equivalent YCs6Y6 cuboctahedra, and faces with twelve equivalent CsCs6Y6 cuboctahedra. All Y–Y bond lengths are 3.84 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsY(PO3)4 by Materials Project

CsY(PO3)4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Cs1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Cs–O bond distances ranging from 3.12–3.39 Å. Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.31–2.45 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There is two shorter (1.50 Å) and two longer (1.63 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cs1+ and two P5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cs1+ and two P5+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, one Y3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Cs1+, one Y3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Cs1+, one Y3+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, one Y3+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one Cs1+, one Y3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one Cs1+, one Y3+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Y3+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to one Cs1+, one Y3+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsY(MoO4)2 by Materials Project

CsY(MoO4)2 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Cs1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Cs–O bond distances ranging from 3.22–3.58 Å. Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.29–2.54 Å. Mo6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.76–1.86 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cs1+ and one Mo6+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cs1+, one Y3+, and one Mo6+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cs1+, one Y3+, and one Mo6+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Mo6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsY(MoO4)2 by Materials Project

CsY(MoO4)2 crystallizes in the orthorhombic Pccm space group. The structure is three-dimensional. Cs1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (3.17 Å) and four longer (3.38 Å) Cs–O bond lengths. Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.31 Å) and four longer (2.50 Å) Y–O bond lengths. Mo6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.75–1.87 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cs1+, one Y3+, and one Mo6+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Mo6+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cs1+ and one Mo6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsY(MoO4)2 by Materials Project

CsY(MoO4)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Cs1+ is bonded to twelve O2- atoms to form CsO12 cuboctahedra that share edges with six equivalent CsO12 cuboctahedra, edges with six equivalent MoO4 tetrahedra, and faces with two equivalent YO6 octahedra. There are six shorter (3.36 Å) and six longer (3.57 Å) Cs–O bond lengths. Y3+ is bonded to six equivalent O2- atoms to form YO6 octahedra that share corners with six equivalent MoO4 tetrahedra and faces with two equivalent CsO12 cuboctahedra. All Y–O bond lengths are 2.26 Å. Mo6+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with three equivalent YO6 octahedra and edges with three equivalent CsO12 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. There is one shorter (1.75 Å) and three longer (1.81 Å) Mo–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cs1+, one Y3+, and one Mo6+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to three equivalent Cs1+ and one Mo6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsI by Materials Project

CsI is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Cs1+ is bonded in a body-centered cubic geometry to eight equivalent I1- atoms. All Cs–I bond lengths are 4.04 Å. I1- is bonded in a body-centered cubic geometry to eight equivalent Cs1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsY(SeO3)2 by Materials Project

CsY(SeO3)2 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. Cs1+ is bonded to twelve equivalent O2- atoms to form CsO12 cuboctahedra that share corners with twelve equivalent CsO12 cuboctahedra and edges with six equivalent YO6 octahedra. There are six shorter (3.30 Å) and six longer (3.52 Å) Cs–O bond lengths. Y3+ is bonded to six equivalent O2- atoms to form YO6 octahedra that share edges with six equivalent CsO12 cuboctahedra. All Y–O bond lengths are 2.28 Å. Se4+ is bonded in a trigonal non-coplanar geometry to three equivalent O2- atoms. All Se–O bond lengths are 1.73 Å. O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Cs1+, one Y3+, and one Se4+ atom.

36 MATERIALS SCIENCE↗