This MATLAB package contains basic functions to compute the (direct and indirect) linear dynamic model of spacecraft. This new version (V 1.3) allows parametric uncertainties to be taken into account (with full compatibility with the MATLAB Robust Control Toolbox). A user guide, some extra examples and a demo file are also included in the STDv1_3 package.
Download :
User Guide :
Reference :
If you publish work that uses this toolbox please refer to this web page and to the following paper :
- Alazard, D., Cumer, C., and Tantawi, K., “Linear dynamic modeling of spacecraft with various flexible appendages and on-board angular momentums”. In Proceedings of the 7th International ESA Conference on Guidance, Navigation & Control Systems Tralee, Ireland, 1-5 June 2008
Description of main functions :
- main : is the main function,
- translate_dynamic_model : to translate a dynamic from one point to another,
- rotate_dynamic_model : to rotate a dynamic model,
- kinematic_model : to compute the kinematic model between 2 points of a body,
- antisym : to compute the antisymetric matrix associated with a vector.
This package contains also example data files :
- Spacecraft1.m is a data file relative to a spacecraft composed of a main body and two flexible appendage cantilevered on the main body,
- Spacecraft2.m is the same than Spacecraft1.m but the first appendage is connected to the main body through a pivot joint and tilted with a 10 degres angle,
- Spacecraft3.m is another data file describing the same spacecraft as Spacecraft2.m but using recursive call to MAIN function. Spacecraft3.m calls data file APPENDAGE1.m to describe the first flexible appendage.
Example :
>>mod1=main(’Spacecraft2’) ;
>>mod2=main(’Spacecraft3’) ;
>>figure,
>>sigma(mod1.DynamicModel-mod2.DynamicModel)
- Spacecraft5.m is the same than Spacecraft1.m but with 3 additionnal appendages corresponding to angular momentums along to X, Y and Z axes (to represent spinned RWA),
- FOUR_CMGs.m is a data file describing a platform fitting with four identical CMGs (Control Moment Gyros). The CMG is decribed by the data file dataCMG.m,
- SpaceRoboticArm.m is a date file describing a platform fitting a 6 d.o.f. rigid space robotic arm : the 6 links of the arm are described in the files Segment1.m, Segment2.m, ..., Segment6.m.
Example :
>> mod=main(’SpaceRoboticArm’) ;
>> mod.liste_IOs % To list and see the order of inputs and outputs of models
- Spacecraft1u.m is another data file describing the same structure than Spacecraft1.m but the main mechanical parameters are uncertain and defined by the function ureal. Then, the outputs of the toolbox main function are uncertain elements, matrices or models, compatible with the Robust Control Toolbox (LFT).
Example :
>> mod=main(’Spacecraft1u’) ;
>> sigma(mod.DynamicModel)
See also : README.m, demoSTD.m (inside the STD v1.3 package)