Search NASA⌕ Search

SEARCH · Search NASA

Results for “control interactions”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Control Structures Interaction (CSI) Technology

Control Structures Interaction (CSI) technology for control of space structures is being developed cooperatively by JPL, LaRC and MSFC for NASA OAST/RM. The mid-'90s goal of JPL's CSI program is to demonstrate with analysis, ground and flight tests, the super quiet structures needed for large diffraction-limited instruments such as optical stellar interferometers and large advanced successors to the Hubble Space Telescope. Microprecision CSI technology is intended as a new "building block" for use by the designers of large optical systems. The thrust of the microprecision CSI technology effort is to achieve nanometer-levels of space structure stability/accuracy with designs which employ otherwise conventional spacecraft technologies. JPL design experiences have indicated the following CSI technology development areas are especially applicable to large optical system projects: (1) Active structural members; (2) Control/structures design methods; (3) Microdynamic effects characterization; and (4) Ground and flight test validation of CSI methods.

Layman, W. E.↗
NASA NTRS1971

Structural interaction with control systems

A monograph which assesses the state of the art of space vehicle design and development is presented. The monograph presents criteria and recommended practices for determining the structural data and a mathematical structural model of the vehicle needed for accurate prediction of structure and control-system interaction; for design to minimize undesirable interactions between the structure and the control system; and for determining techniques to achieve the maximum desirable interactions and associated structural design benefits. All space vehicles are treated, including launch vehicles, spacecraft, and entry vehicles. Important structural characteristics which affect the structural model used for structural and control-system interaction analysis are given.

Noll, R. B.↗
NASA NTRS1987

Analyzing Feedback Control Systems

Interactive controls analysis (INCA) program developed to provide user-friendly environment for design and analysis of linear control systems, primarily feedback control. Designed for use with both small- and large-order systems. Using interactive-graphics capability, INCA user quickly plots root locus, frequency response, or time response of either continuous-time system or sampled-data system. Configuration and parameters easily changed, allowing user to design compensation networks and perform sensitivity analyses in very convenient manner. Written in Pascal and FORTRAN.

Bauer, Frank H.↗
NASA NTRS1990

Computer implementation of analysis and optimization procedures for control-structure interaction problems

Implementation aspects of control-structure interaction analysis and optimization by the staggered use of single-discipline analysis modules are discussed. The single-discipline modules include structural analysis, controller synthesis and optimization. The software modularity is maintained by employing a partitioned control-structure interaction analysis procedure, thus avoiding the need for embedding the single-discipline modules into a monolithic program. A software testbed has been constructed as a stand-alone analysis and optimization program and tested for its versatility and software modularity by applying it to the dynamic analysis and preliminary design of a prototype Earth Pointing Satellite. Experience with the in-core testbed program so far demonstrates that the testbed is efficient, preserves software modularity, and enables the analyst to choose a different set of algorithms, control strategies and design parameters via user software interfaces. Thus, the present software architecture is recommended for adoption by control-structure interaction analysts as a preliminary analysis and design tool.

Belvin, W. Keith↗
NASA NTRS1990

Controls structures interaction, an interdisciplinary challenge for large spacecraft

Controls structures interaction (CSI), a phenomenon which occurs when control forces interact with the flexible motion of a structure, can, if improperly treated in design and development, cause reduced performance or control instabilities. Properly applied, it can improve flexible spacecraft performance. In this paper, the NASA CSI technology program for future spacecraft applications is described. The program objectives and organization are outlined, and the nature of individual program tasks is described. The interdisciplinary aspects of CSI are also addressed.

Hanks, Brantley R.↗
NASA NTRS1982

Power, thermal, and attitude control design interactions of the CCE/AMPTE spacecraft

The power, thermal and attitude control interactions of the CCE spacecraft and the design compromises resulting from these interactions are described. These compromises result from the conflict between the plane change maneuver requirements and the final on station requirements. The resolution of these conflicts to arrive at an acceptable final design, is given and the resulting power, thermal and attitude control systems are described in some detail.

Wingate, C. A., Jr.↗
NASA NTRS1989

Control-structure interaction in precision pointing servo loops

The control-structure interaction problem is addressed via stability analysis of a generic linear servo loop model. With the plant described by the rigid body mode and a single elastic mode, structural flexibility is categorized into one of three types: (1) appendage, (2) in-the-loop minimum phase, and (3) in-the-loop nonminimum phase. Closing the loop with proportional-derivative (PD) control action and introducing sensor roll-off dynamics in the feedback path, stability conditions are obtained. Trade studies are conducted with modal frequency, modal participation, modal damping, loop bandwidth, and sensor bandwidth treated as free parameters. Results indicate that appendage modes are most likely to produce instability if they are near the sensor rolloff, whereas in-the-loop modes are most dangerous near the loop bandwidth. The main goal of this paper is to provide a fundamental understanding of the control-structure interaction problem so that it may benefit the design of complex spacecraft and pointing system servo loops. In this framework, the JPL Pathfinder gimbal pointer is considered as an example.

Spanos, John T.↗
NASA NTRS1980

Control-structure interaction in a free beam

A simple energy approach to study the problem of control structure interactions in large space structures is presented. For the illustrative case of a free-free beam, the vibrational energy imparted during operation of constant, step, and pulsed thrusters is found in a nondimensional closed form. Then based on a parametric study, suggestions are made on the choice of parameters to minimize the control structure interactions. The study of this simple system provides physical insight and understanding for more complex systems.

Shrivastava, S. K.↗
NASA NTRS1990

The NASA controls-structures interaction technology program

The interaction between a flexible spacecraft structure and its control system is commonly referred to as controls-structures interaction (CSI). The CSI technology program is developing the capability and confidence to integrate the structure and control system, so as to avoid interactions that cause problems and to exploit interactions to increase spacecraft capability. A NASA program has been initiated to advance CSI technology to a point where it can be used in spacecraft design for future missions. The CSI technology program is a multicenter program utilizing the resources of the NASA Langley Research Center (LaRC), the NASA Marshall Space Flight Center (MSFC), and the NASA Jet Propulsion Laboratory (JPL). The purpose is to describe the current activities, results to date, and future activities of the NASA CSI technology program.

Newsom, Jerry R.↗
NASA NTRS1990

The NASA controls-structures interaction technology program

The interaction between a flexible spacecraft structure and its control system is commonly referred to as controls-structures interaction (CSI). The CSI technology program is developing the capability and confidence to integrate the structure and control system, so as to avoid interactions that cause problems and to exploit interactions to increase spacecraft capability. A NASA program has been initiated to advance CSI technology to a point where it can be used in spacecraft design for future missions. The CSI technology program is a multicenter program utilizing the resources of the NASA Langley Research Center, the NASA Marshall Space Flight Center, and the NASA Jet Propulsion Laboratory. The purpose of this paper is to describe the current activities, results to date, and future activities of the NASA CSI technology program.

Newsom, Jerry R.↗
NASA NTRS1990

Control-Structure-Interaction (CSI) technologies and trends to future NASA missions

Control-structure-interaction (CSI) issues which are relevant for future NASA missions are reviewed. This goal was achieved by: (1) reviewing large space structures (LSS) technologies to provide a background and survey of the current state of the art (SOA); (2) analytically studying a focus mission to identify opportunities where CSI technology may be applied to enhance or enable future NASA spacecraft; and (3) expanding a portion of the focus mission, the large antenna, to provide in-depth trade studies, scaling laws, and methodologies which may be applied to other NASA missions. Several sections are presented. Section 1 defines CSI issues and presents an overview of the relevant modeling and control issues for LLS. Section 2 presents the results of the three phases of the CSI study. Section 2.1 gives the results of a CSI study conducted with the Geostationary Platform (Geoplat) as the focus mission. Section 2.2 contains an overview of the CSI control design methodology available in the technical community. Included is a survey of the CSI ground-based experiments which were conducted to verify theoretical performance predictions. Section 2.3 presents and demonstrates a new CSI scaling law methodology for assessing potential CSI with large antenna systems.

Source record↗
NASA NTRS1983

Control structure interactions in large space structures Analysis using energy approach

A simple energy approach to study the problem of control structure interactions in large space structures is presented. For the illustrative cases of free-free beam and free rectangular plate, the vibrational energy imparted during operation of constant and pulsed thrusters is found in a nondimensional form. Then based on a parametric study, suggestions are made on the choice of the thruster location and parameters to minimize the control structure interactions.

Shrivastava, S. K.↗
NASA NTRS1973

Simulation of flexible appendage interactions with Mariner Venus/Mercury attitude control and science platform pointing

A new computer subroutine, which solves the attitude equations of motion for any vehicle idealized as a topological tree of hinge-connected rigid bodies, is used to simulate and analyze science instrument pointing control interaction with a flexible Mariner Venus/Mercury (MVM) spacecraft. The subroutine's user options include linearized or partially linearized hinge-connected models whose computational advantages are demonstrated for the MVM problem. Results of the pointing control/flexible vehicle interaction simulations, including imaging experiment pointing accuracy predictions and implications for MVM science sequence planning, are described in detail.

Fleischer, G. E.↗
NASA NTRS1989

Laboratory studies of wave-current interaction - Kinematics of the strong interaction

Controlled laboratory experiments have been conducted to study the kinematics of wave-current interactions. The results confirm the conservation of waves under the steady state condition. The data also show that the kinematic effect of the current on waves can be treated as a simple Doppler shift. After the Doppler correction, the kinematics of the waves (either breaking or nonbreaking) follow the linear theory very well.

Lai, Ronald J.↗
NASA NTRS1991

Controls-Structures Interaction (CSI) technology program summary. Earth orbiting platforms program area of the space platforms technology program

Control-Structures Interaction (CSI) technology embraces the understanding of the interaction between the spacecraft structure and the control system, and the creation and validation of concepts, techniques, and tools, for enabling the interdisciplinary design of an integrated structure and control system, rather than the integration of a structural design and a control system design. The goal of this program is to develop validated CSI technology for integrated design/analysis and qualification of large flexible space systems and precision space structures. A description of the CSI technology program is presented.

Newsom, Jerry R.↗