GetStarted file for the SDTLIB demos.
1. Installation
The required MATLAB configuration for the SDTLIB_v1_1 demos:
- MATLAB R2020b or later,
- control_toolbox
- robust_toolbox
- simulink
- simulink_control_design
Once the folder SDTLIB_V1_1_demo_R2020b folder is unzipped on your computer at: yourDirectory>SDTLIB_V1_1_demo_R2020b, you can launch MATLAB and give the path to this folder by navigating to the yourDirectory folder using the Current Folder Toolbar and :
- select SDTLIB_V1_1_demo_R2020b in the Current Folder Brower and then right-click on Add to path > Selected Folders and Subfolders,
- or type the following command in the Command Window
addpath(genpath('SDTLIB_V1_1_demo_R2020b'))
2. DEMO
The subfolder DEMO contains 2 live scripts and the associated SIMULINK files to run 2 demos
- Demo1: (file SDTlibDEMO1.mlx). This demo shows how to use the SDTlib to build the model of a flexible spacecraft.
- Demo2: (file SDTlibDEMO2.mlx). This demo shows how to perform robust control design and analysis based on the model built with the SDTlib and the Robust Control Toolbox.
The subfolder SDTfct contains a light version of the SDTLIB_V1_1 functions and documentations.
3. Important notices
- You can copy and paste the SDTlib blocks used in the various SIMULINK demo files to build your own models.
- Running the SDTlibDEMO2.mlx live script may lead to different results depending on the MATLAB version. It is recommended to save it under another name before running it. In all cases, the PDF extractions of the live scripts (after a run under MATLAB R2020b) are saved in the files: SDTlibDEMO1_compressed.pdf and SDTlibDEMO2_compressed.pdf.
4. To go further
This demo files aim at demonstrating the capacity of the SDTlib to model, analyze, and control space systems. The full version of SDTlib offers many more features to model flexible multi-body systems, including: NASTRAN/PATRAN interfaces, flexible beams and plates, revolute joints, mechanims, on-board angular momentums... The user is invited to download the SDTlib User's Manual here for an in-depth overview of SDTlib. A list of some of our most recent application studies, all based on the SDTlib, is provided here with the associated publications: - Fine line-of-sight control with disturbance rejection: A spacecraft is modeled to take into account flexible solar arrays, and two other sources of microvibrations, namely reaction wheels imbalances and solar array drive mechanism. A control architecture is proposed, based on fast-steering mirrors and a set of proff-mass actuators, to control the line-of-sight of an optical scientific instrument. A robust controller is tuned to guarantee stringent line-of-sight pointing requirements despite the harmonic disturbances coupled with the flexible dynamics. [Sanfedino, F., Thiébaud, G., Alazard, D., Guercio, N., & Deslaef, N. (2022). Advances in Fine Line-Of-Sight Control for Large Space Flexible Structures. arXiv preprint arXiv:2209.13374.]
- Structure/control co-design with a truss structure: A complex truss structure is modeled. Then, a robust control/structure co-design approach is proposed to minimize the mass of the spacecraft while robustly ensuring pointing requirements of an antenna, in one single optimization problem. [Finozzi, A., Sanfedino, F., & Alazard, D. (2022). Parametric sub-structuring models of large space truss structures for structure/control co-design. Mechanical Systems and Signal Processing, 180, 109427.]
- On-orbite servicing: The different phased of an on-orbit servicing mission are modeled in one single SDT model, including the large inertia and flexibility changes occuring during the rendez-vous due to the different coupled or decoupled chaser/target configurations. A controller is tuned to take into account all interactions between the subsystems as well as uncertain and time-carying parameters and coupled flexible dynamics. [Rodrigues, R., Preda, V., Sanfedino, F., & Alazard, D. (2022). Modeling, robust control synthesis and worst-case analysis for an on-orbit servicing mission with large flexible spacecraft. Aerospace Science and Technology, 107865.]
- Modeling of microvibration sources: A generic model of the harmonic disturbances generated by a solar array driving mechanism is developed, and validated using on-board telemetry data of a European spacecraft. A worst-case robust analysis is carried out to analyze the impact of the microvibrations on the pointing error, and a Linear Parameter Varying observer, scheduled by the solar array rotor angle, is proposed to estimate the disturbance torque induced by the gearbox imperfections. [Sanfedino, F., Alazard, D., Preda, V., & Oddenino, D. (2022). Integrated modeling of microvibrations induced by Solar Array Drive Mechanism for worst-case end-to-end analysis and robust disturbance estimation. Mechanical Systems and Signal Processing, 163, 108168.]
- Hybrid sensing and control: The robust control framework is used to tune an optimal estimation of the line-of-sight based on the multi-sensors fusion of a CCD camera with a fast angular rate sensor to extend the bandwith of the active disturbance rejection control. The results are validated on an experimental bench developed at ESA. [Sanfedino, F., Preda, V., Pommier-Budinger, V., Alazard, D., Boquet, F., & Bennani, S. (2020). Robust active mirror control based on hybrid sensing for spacecraft line-of-sight stabilization. IEEE Transactions on Control Systems Technology, 29(1), 220-235.]
In addition, some publications related to ongoing developments:
- [Kassarian E., Sanfedino F., Alazard; D., Chevrier C.A., Montel J. (2022). Linear Fractional Transformation Modeling of Multibody Dynamics Around Parameter-Dependent Equilibrium. IEEE Transactions on Control Systems Technology.]
- [Kassarian E., Sanfedino F., Alazard; D., Montel J., Chevrier C.A. (2022). Robust integrated control/structure co-design for stratospheric balloons. 10th IFAC Symposium on Robust Control Design ROCOND 2022, Kyoto, Japan]