@presentation{Lee2020AASGNC,
    author = "Lee, Yong Hoon and Vedant and Allison, James T.",
    title = "Computationally-efficient modeling and optimization of strain-actuated solar arrays with tailored viscoelastic damping for spacecraft attitude control",
    booktitle = "AAS Guidance and Control Conference",
    address = "Breckenridge, CO, USA",
    year = "2020",
    month = feb,
%    number = "",
%    pages = "",
    pdf = "http://hdl.handle.net/2142/106101",
%    doi = "",
%    gsid = "",
%    note = "",
    abstract = "The recently-introduced strain-actuated solar array (SASA) spacecraft attitude control system (ACS) is expected to enable new levels of pointing precision for next-generation space observatories. Previous work has shown that tailored passive viscoelastic damping can help mitigate control system complexity by using passive damping to manage high-frequency vibration modes, while the active control system focuses on lower-frequency dynamics. Viscoelastic materials (VEMs) exhibit hysteretic behavior, requiring the use of computationally-expensive models based on integro-differential equations. A class of ap-proximations is presented here where convolution integrals are replaced with transfer func-tions to reduce computational expense significantly, supporting the application of control co-design optimization, while maintaining requisite accuracy. This approach eliminates time history integration needed for derivative function calculation, which opens up the possibil-ity of using general optimal control toolkits as well as advanced computationally-efficient methods for approximating system dynamics derivative functions.",
}