{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/97505"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/97505","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Assessment of moving-mass actuators for hypersonic vehicles with deployable decelerators","abstract":"This study assesses internal moving-mass actuator configuration options for trajectory control in the hypersonic regime of planetary entry. Trajectory control is achieved by shifting the location of the center of gravity relative to the center of pressure to modify aerodynamic trim conditions. The vehicle is modeled as a cylinder with a deployable forebody and a moving-mass actuator that can translate along a linear track. Placing the track in the rear of the vehicle can reduce the required actuator mass fraction for a specific trim lift-to-drag ratio by up to 5%. Increasing the length of the track similarly reduces required mass fraction. Vehicle packaging density and size do not significantly influence the required actuator mass; geometric properties such as length-to-diameter ratio and the diameter of the deployable impact the required actuator mass. Using these design guidelines, and actuator mass fraction of approximately 13% is required to achieve a maximum lift-to-drag ration similar to the Mars Science Laboratory. A range of expected hypersonic flight conditions are analyzed to determine their impact on the achievable lift-to-drag ratio. For a moving-mass actuator mass fraction of 1%, the available lift-to-drag ratio varies between 0.02 and 0.06; for a 5% mass fraction the available lift-to-drag ratio varies between 0.1 to 0.13. A study of the system response is presented across vehicle geometries, and mass motions. A preliminary closed-loop PD control is presented which reduces the 2% settling time from 9 seconds to 5 seconds and removes all oscillations. An optimal control formulation is then solved, to minimize time, which reduces the settling time from 5 seconds to 0.6 seconds. The optimal control solutions move the mass primarily in the z direction, and adding a vertical constraint to the problem only marginally increases the settling time.","abstract_html":"This study assesses internal moving-mass actuator configuration options for trajectory control in the hypersonic regime of planetary entry. Trajectory control is achieved by shifting the location of the center of gravity relative to the center of pressure to modify aerodynamic trim conditions. The vehicle is modeled as a cylinder with a deployable forebody and a moving-mass actuator that can translate along a linear track. Placing the track in the rear of the vehicle can reduce the required actuator mass fraction for a specific trim lift-to-drag ratio by up to 5%. Increasing the length of the track similarly reduces required mass fraction. Vehicle packaging density and size do not significantly influence the required actuator mass; geometric properties such as length-to-diameter ratio and the diameter of the deployable impact the required actuator mass. Using these design guidelines, and actuator mass fraction of approximately 13% is required to achieve a maximum lift-to-drag ration similar to the Mars Science Laboratory. A range of expected hypersonic flight conditions are analyzed to determine their impact on the achievable lift-to-drag ratio. For a moving-mass actuator mass fraction of 1%, the available lift-to-drag ratio varies between 0.02 and 0.06; for a 5% mass fraction the available lift-to-drag ratio varies between 0.1 to 0.13. A study of the system response is presented across vehicle geometries, and mass motions. A preliminary closed-loop PD control is presented which reduces the 2% settling time from 9 seconds to 5 seconds and removes all oscillations. An optimal control formulation is then solved, to minimize time, which reduces the settling time from 5 seconds to 0.6 seconds. The optimal control solutions move the mass primarily in the z direction, and adding a vertical constraint to the problem only marginally increases the settling time.","abstract_has_math":false,"creators":["Lohan, Kevin George"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Putnam, Zachary R."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-08-10T19:16:19Z","date_published":"2017-08-10T19:16:19Z","updated_at":"2026-07-22T22:24:34Z","subjects":["Moving-mass","Control"],"languages":["en"],"rights":["Copyright 2017 Kevin Lohan"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/97505","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Putnam, Zachary R."]},{"key":"dc:creator","label":"Author","values":["Lohan, Kevin George"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-08-10T19:16:19Z","2017-04-28","2017-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Moving-mass","Control"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Kevin Lohan"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/97505"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This study assesses internal moving-mass actuator configuration options for trajectory control in the hypersonic regime of planetary entry. Trajectory control is achieved by shifting the location of the center of gravity relative to the center of pressure to modify aerodynamic trim conditions. The vehicle is modeled as a cylinder with a deployable forebody and a moving-mass actuator that can translate along a linear track. Placing the track in the rear of the vehicle can reduce the required actuator mass fraction for a specific trim lift-to-drag ratio by up to 5%. Increasing the length of the track similarly reduces required mass fraction. Vehicle packaging density and size do not significantly influence the required actuator mass; geometric properties such as length-to-diameter ratio and the diameter of the deployable impact the required actuator mass. Using these design guidelines, and actuator mass fraction of approximately 13% is required to achieve a maximum lift-to-drag ration similar to the Mars Science Laboratory. A range of expected hypersonic flight conditions are analyzed to determine their impact on the achievable lift-to-drag ratio. For a moving-mass actuator mass fraction of 1%, the available lift-to-drag ratio varies between 0.02 and 0.06; for a 5% mass fraction the available lift-to-drag ratio varies between 0.1 to 0.13. A study of the system response is presented across vehicle geometries, and mass motions. A preliminary closed-loop PD control is presented which reduces the 2% settling time from 9 seconds to 5 seconds and removes all oscillations. An optimal control formulation is then solved, to minimize time, which reduces the settling time from 5 seconds to 0.6 seconds. The optimal control solutions move the mass primarily in the z direction, and adding a vertical constraint to the problem only marginally increases the settling time.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Kevin Lohan, accepted the attached license on 2017-04-27 at 11:09.","The student, Kevin Lohan, submitted this Thesis for approval on 2017-04-27 at 11:29.","This Thesis was approved for publication on 2017-04-28 at 10:39.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11110 on 2017-08-10 at 13:46:54","Made available in DSpace on 2017-08-10T19:16:19Z (GMT). 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The vehicle is modeled as a cylinder with a deployable forebody and a moving-mass actuator that can translate along a linear track. Placing the track in the rear of the vehicle can reduce the required actuator mass fraction for a specific trim lift-to-drag ratio by up to 5%. Increasing the length of the track similarly reduces required mass fraction. Vehicle packaging density and size do not significantly influence the required actuator mass; geometric properties such as length-to-diameter ratio and the diameter of the deployable impact the required actuator mass. Using these design guidelines, and actuator mass fraction of approximately 13% is required to achieve a maximum lift-to-drag ration similar to the Mars Science Laboratory. A range of expected hypersonic flight conditions are analyzed to determine their impact on the achievable lift-to-drag ratio. For a moving-mass actuator mass fraction of 1%, the available lift-to-drag ratio varies between 0.02 and 0.06; for a 5% mass fraction the available lift-to-drag ratio varies between 0.1 to 0.13. A study of the system response is presented across vehicle geometries, and mass motions. A preliminary closed-loop PD control is presented which reduces the 2% settling time from 9 seconds to 5 seconds and removes all oscillations. An optimal control formulation is then solved, to minimize time, which reduces the settling time from 5 seconds to 0.6 seconds. The optimal control solutions move the mass primarily in the z direction, and adding a vertical constraint to the problem only marginally increases the settling time.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Kevin Lohan, accepted the attached license on 2017-04-27 at 11:09.","The student, Kevin Lohan, submitted this Thesis for approval on 2017-04-27 at 11:29.","This Thesis was approved for publication on 2017-04-28 at 10:39.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11110 on 2017-08-10 at 13:46:54","Made available in DSpace on 2017-08-10T19:16:19Z (GMT). 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