Generalized modelling of a space station and determination of the transfer function

An elementary structural model of a modular space station, such as the Russian Space Station Mir or the International Space Station (ISS), was formulated using Euler-Bernoulli beam theory. Based on structural dynamic techniques and modal analysis, a generalized method for deriving a theoretical transfer function between astronaut force inputs and station acceleration outputs is postulated. The validity of this transfer function can then be examined using the experimental force and acceleration data collected from Mir from the period of 1996 to 1998. In order to quantify astronaut-induced disturbances to the microgravity environment onboard a space station during long duration spaceflight, the Enhanced Dynamic Load Sensors (EDLS) Spaceflight experiment measured the forces and moments exerted by astronauts on the Russian Space Station Mir. Approximately 95% of all processed astronaut motions possessed a maximum force less that 275 N, a root mean square force less than 60 N and a power spectral density less than 22 Hz. Thus, astronaut motions are not the most stringent of design constraints upon a space station. Coupled with accelerometer data from the Space Acceleration Measurement System (SAMS), forces from crew motions can be temporally correlated with the overall acceleration of the Mir Space Station. An operator similar to the Fourier transform is developed in order to convert the force and acceleration data from the time domain into the frequency domain. A least-squares approach is used in order to obtain the optimal transfer function between the force and acceleration experimental data. The maximum residue of this transfer function was found at the pole at 0.375 Hz with a magnitude of approximately 7.5x10 -6, which is in accord with transient time domain analysis performed previously. Unfortunately, due to a lack of collocation between the EDLS force plate sensors and the SAMS accelerometer heads, a meaningful comparison between the theoretical transfer function and the experimental transfer function could not be conducted. Thesis Supervisor: Dava J. Newman, Ph.D. Title: Associate Professor of Aeronautics and Astronautics

[1]  Glenn K. Klute.  Pilot Investigation: Nominal Crew Induced Forces in Zero-G , 1992 .

[2]  Sasan Armand,et al.  Modal Test/Analysis Correlation of Space Station Structures Using Nonlinear Sensitivity , 1992 .

[3]  William A. Sethares,et al.  Sensor placement for on-orbit modal identification via a genetic algorithm , 1993 .

[4]  Richard A. Brown,et al.  Introduction to random signals and applied kalman filtering (3rd ed , 2012 .

[5]  Harvey J. Willenberg,et al.  Characterization of the microgravity environment on the Salyut and Mir space stations , 1994, Defense, Security, and Sensing.

[6]  R. Macneal.  A hybrid method of component mode synthesis , 1971 .

[7]  Douglas A. Rohn,et al.  The impact of an IVA robot on the Space Station microgravity environment , 1989 .

[8]  B. A. Conway.  Mathematical crew motion disturbance models for spacecraft control system design. M.S. Thesis - George Washington Univ. , 1974 .

[9]  Peter M. Bainum,et al.  Motion of Spinning Spacecraft with Hinged Appendages , 1977 .

[10]  S. N. Patnaik,et al.  Singularities in optimal structural design , 1992 .

[11]  Steven A. Scheer,et al.  Crew activity and motion effects on the space station , 1987 .

[12]  P. Kulla.  Dynamics of Spinning Bodies Containing Elastic Rods , 1972 .

[13]  S. Del Basso.  The International Space Station microgravity experiment , 1996 .

[14]  Charles R. Baugher,et al.  Development of and flight results from the Space Acceleration Measurement System (SAMS) , 1992 .

[15]  Michael Tinker,et al.  Modal vibration test facilities and methods for space station modules , 1995 .

[16]  Juang J-N.,et al.  A Benchmark Problem for Development of Autonomous Structural Modal Indentification , 1996 .

[17]  Richard DeLombard,et al.  Microgravity environment countermeasures - Panel discussion , 1997 .

[18]  Richard DeLombard.  SAMS Acceleration Measurements on Mir (NASA Increment 4) , 1998 .

[19]  Vinod J. Modi,et al.  An approach to dynamics of flexible orbiting systems with application to the proposed space station , 1992 .

[20]  Thomas J. Sutliff.  An acceleration measurement capability on International Space Station supporting microgravity science payloads , 1997 .

[21]  B. A. Conway.  Investigation of crew motion disturbances on Skylab-Experiment T-013. [for future manned spacecraft design] , 1974 .

[22]  L. Meirovitch.  A Stationarity Principle for the Eigenvalue Problem for Rotating Structures , 1976 .

[23]  Jiann-Shiun Lew,et al.  Transfer Function Parameter Changes Due to Structural Damage , 1997 .

[24]  R. Roberson,et al.  A dynamical formalism for an arbitrary number of interconnected rigid bodies, with reference to the problem of satellite attitude control. , 1966 .

[25]  Banavar Sridhar.  Identification of space station dynamics , 1985, 1985 24th IEEE Conference on Decision and Control.

[26]  Kenneth Hrovat,et al.  An overview of the microgravity environment and its effects on science , 1996 .

[27]  J.Y.L. Ho,et al.  Direct Path Method for Flexible Multibody Spacecraft Dynamics (Originally schedulled for publication in the AIAA Journal) , 1977 .

[28]  Milton E. Moskowitz,et al.  Comparison tools for assessing the microgravity environment of space missions, carriers, and conditions , 1998, Defense, Security, and Sensing.

[29]  P. Likins,et al.  Mathematical modeling of spinning elastic bodies for modal analysis. , 1973 .

[30]  Richard DeLombard,et al.  Further analysis of the microgravity environment on Mir Space Station during Mir-16 , 1996 .

[31]  W. H. Roberts,et al.  Band Lanczos vibration analysis of aerospace structures , 1991 .

[32]  Richard DeLombard.  Compendium of Information for Interpreting the Microgravity Environment of the Orbiter Spacecraft , 1996 .

[33]  Richard Delombard,et al.  Microgravity environment of STS-57 and summary comparison with selected previous missions , 1994 .

[34]  Judith Robey.  Planning for microgravity science research on the International Space Station , 1997 .

[35]  M. C. Kullas.  Handbook on astronaut crew motion disturbances for control system design. [in skylab] , 1979 .

[36]  William W. Durgin,et al.  A Comparison of Low-Gravity Measurements On-Board Columbia During STS-40 , 1993 .

[37]  Oddvar O. Bendiksen,et al.  Structures, Structural Dynamics and Materials Conference , 1998 .

[38]  Bruce A. Conway,et al.  A summary of the Skylab crew/vehicle disturbances experiment T-013 , 1976 .

[39]  Michael L. Tinker,et al.  Mass-additive modal test method for verification of constrained structural models , 1993 .

[40]  William W. Hooker,et al.  The Dynamical Attitude Equations for n-Body Satellite , 1965 .

[41]  Gerald V. Brown,et al.  Low frequency vibration isolation technology for microgravity space experiments , 1989 .

[42]  Richard Delombard,et al.  Space acceleration measurement system description and operations on the First Spacelab Life Sciences Mission , 1991 .

[43]  Eric Feron,et al.  Time-Frequency Analysis for Transfer Function Estimation and Application to Flutter Clearance , 1998 .

[44]  Amir R. Amir.  Design and development of advanced load sensors for the International Space Station , 1998 .

[45]  Edward F. Crawley,et al.  Development of Structural Uncertainty Models , 1997 .

[46]  S. E. Morgan.  Avoiding On-Orbit Control/Structure Interaction Problems with Space Station Freedom , 1992 .

[47]  W. T. Thomson,et al.  Instability of spinning space stations due to crew motion , 1965 .

[48]  Corrado Poli,et al.  Effect of man's motion on the attitude of a satellite. , 1967 .

[49]  Goodarz Ahmadi,et al.  Evaluation of Passive and Active Vibration Control Mechanisms in a Microgravity Environment , 1993 .

[50]  Milton E. Moskowitz,et al.  SAMS Acceleration Measurements on MIR , 1997 .

[51]  D J Newman,et al.  Astronaut-induced disturbances in microgravity. , 1997, Journal of spacecraft and rockets.

[52]  S. Rubin.  Improved Component-Mode Representation for Structural Dynamic Analysis , 1975 .

[53]  Roy R. Craig,et al.  Structural Dynamics: An Introduction to Computer Methods , 1981 .

[54]  Paul P. Lin,et al.  Influence of mass moment of inertia on the normal modes of a preloaded solar array mast , 1993 .

[55]  Robert Rhome,et al.  Achievements in microgravity - Ten years of microgravity research , 1994 .