by Lee, Yong Hoon, Vedant and Allison, James T.
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.
Reference:
Yong Hoon Lee, Vedant and James T. Allison, "Computationally-efficient modeling and optimization of strain-actuated solar arrays with tailored viscoelastic damping for spacecraft attitude control", in AAS Guidance and Control Conference, Breckenridge, CO, USA, February 2020.
Bibtex Entry:
@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 = "", % comment = "", 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.", }