报告题目: Double-stage active control of micro-vibrations for high accuracy pointing space missions
报告人: Daniel Alazard (ISAE-SUPAERO)
报告时间: 2024年7月18日（周四）14:00
报告地点：18号楼705会议室
主办单位：威廉体育官方app下载 国际合作处
报告内容简介：
The increased need in pointing performance for Earth observation and science Space missions together with the use of lighter and flexible structures directly come with the need of a robust pointing performance budget from the very beginning of the mission design. An extensive understanding of the system physics and its uncertainties is then necessary in order to push control design to the limits of performance and constrains the choice of the set of sensors and actuators.
A multi-body framework, the Two Input Two Output Ports approach, is used to build all the elementary flexible bodies and mechanisms involved in a fine pointing mission. This framework allows the authors to easily include all system dynamics with an analytical dependency on varying and uncertain mechanical parameters in a unique Linear Fractional Transformation (LFT) model. This approach opens the doors to modern robust control techniques that robustly guarantee the expected fine pointing requirements. In particular, a novel control architecture is proposed to reduce the micro-vibrations induced both by reaction wheel imbalances and Solar Array Drive Mechanism driving signal, by letting them work during the imaging phase. Thanks to a set of accelerometers placed at the isolated base of the payload and in correspondence of the mirrors with the largest size in a Space telescope (typically the primary and secondary ones), it is possible to estimate the line-of-sight error at the payload level by hybridizing them with the low-frequency measurements of the camera. While a classical Fast Steering Mirror in front of the camera can compensate for a large amount of micro-vibration, an innovative architecture with a set of six Proof-Mass Actuators installed at the payload isolator level can further improve the pointing performance.
报告人简介:
Daniel Alazard graduated from “Ecole Nationale Supérieure des Arts et Métiers” in 1986 (golden medal) and got his Master of Science in Advanced Automatic Control and Systems at SUPAERO (honors) in 1987. Between 1989 and 2000 he was enrolled as a scientist at ONERA, the French Aerospace Lab. Since 2000 he is a full Professor at ISAE-SUPAERO. His main domains of interest are the dynamics and control of Aerospace vehicles and more particularly the modeling and control of very large space structures. He passed the Accreditation to Supervize Research (HDR) at Université Paul Sabatier, Toulouse, in 2003. He supervised or co-supervized more than 20 PhDs and is author or co-author of more than 120 communications or papers and several books. He is also AIAA Associate Fellow and the co-founder of the startup DYCSYT.
