This paper presents a preliminary control design for the test mass release phase of the LISA space mission. LISA will be a gravitational wave observatory that consists in a triangular constellation of spacecraft, each of which carries two free falling test masses needed for the scientific experiment. Each test mass is a cubic body contained inside an electrostatic suspension and is initially locked by a clamp mechanism. Once the spacecraft enters its final orbit, the clamps are retracted, and the test masses are released. To perform science, each test mass must be positioned at the cage centre with a specific attitude. However, the low actuation authority of the electrostatic suspension along with the critical initial conditions provided by the clamp retraction, make the attitude and translation control of the test mass a difficult task. Model Predictive Control (MPC) is a suitable technique for this application because provides optimal (eventually sub-optimal) inputs by solving a constrained optimization problem online. The nonlinear model of the plant was obtained to set up a simulation environment. Then, it was linearized obtaining the internal predictive model of the MPC. Finally, the MPC controller was designed and tuned in simulation achieving satisfactory results.
The LISA DFACS: Preliminary Model Predictive Control Design for the Test Mass Release Phase / Vidano, Simone; Novara, Carlo; Grzymisch, Jonathan; Pagone, Michele. - ELETTRONICO. - (In corso di stampa). ((Intervento presentato al convegno 71st International Astronautical Congress tenutosi a Virtual conference instead of Dubai (COVID-19 Pandemic) nel 12-14 October 2020.
Titolo: | The LISA DFACS: Preliminary Model Predictive Control Design for the Test Mass Release Phase |
Autori: | |
Data di pubblicazione: | Being printed |
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Abstract: | This paper presents a preliminary control design for the test mass release phase of the LISA spac...e mission. LISA will be a gravitational wave observatory that consists in a triangular constellation of spacecraft, each of which carries two free falling test masses needed for the scientific experiment. Each test mass is a cubic body contained inside an electrostatic suspension and is initially locked by a clamp mechanism. Once the spacecraft enters its final orbit, the clamps are retracted, and the test masses are released. To perform science, each test mass must be positioned at the cage centre with a specific attitude. However, the low actuation authority of the electrostatic suspension along with the critical initial conditions provided by the clamp retraction, make the attitude and translation control of the test mass a difficult task. Model Predictive Control (MPC) is a suitable technique for this application because provides optimal (eventually sub-optimal) inputs by solving a constrained optimization problem online. The nonlinear model of the plant was obtained to set up a simulation environment. Then, it was linearized obtaining the internal predictive model of the MPC. Finally, the MPC controller was designed and tuned in simulation achieving satisfactory results. |
Appare nelle tipologie: | 4.1 Contributo in Atti di convegno |
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http://hdl.handle.net/11583/2839190