Dynamics and control of flexible spacecraft : a case study

The First Milestone Configuration (FMC) of the proposed Space Station Freedom is considered for investigating the dynamics and control aspects of a space based orbiting flexible structure. The system dynamics is governed by an extremely lengthy (even in the matrix form), highly nonlinear, nonautonomous and coupled set of equations amenable only to a numerical solution. Two distinctly different discretization procedures, using the system modes and the component modes, are applied to the design as well as the Lagrange orientations of the FMC. The system is found to be inherently unstable suggesting the need for control. To this end two control techniques are employed: the classical Linear Quadratic Regulator (LQR) is applied to the linearized set of governing equations of motion; and the Feedback Linearisation Technique (FLT) for the complete nonlinear set. The amount of information obtained through a planned parametric study of the system dynamics and control is indeed enormous. The results clearly show that under critical combinations of parameters the system can become unstable. However, both the LQR and FLT procedures, together with the on board Control Momentum Gyros (CMG's), can restore the system to the equilibrium state. To gain better insight into the physics of the system behaviour, the uncontrolled as well as the controlled responses of the FMC are animated on an IRIS graphics workstation. The thesis ends with a few recommendations for future study.

Name thesis:degree_name

Master of Applied Science - MASc

Level thesis:degree_level

master's

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor dc:publisher

University of British Columbia

Year dc:date

1992

Author dc:creator

• Muneer, Khan Mohd

Statement dc:rights

• For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

Language dc:language

eng

Handle dc:identifier

http://hdl.handle.net/2429/1123

OAI identifier oai:identifier

oai:circle.library.ubc.ca:2429/1123