UBC Theses and Dissertations
Dynamics and control of orbiting deployable multimodule manipulators Cao, Yang
This thesis focuses on the planar dynamics and control of a variable geometry manipulator which may be used in space- as well as ground-based operations. The system is composed of a flexible orbiting platform supporting two modules connected in a chain topology. Each module consists of two links: one free to slew while the other permitted to deploy. The model used and the governing order-N equations of motion, as developed by Caron, are explained. A detailed dynamical response study is undertaken which assesses the influence of initial conditions, system parameters, and manipulator maneuvers on the system response. Results suggest that under critical combinations of system parameters and disturbances the response may not conform to the acceptable limit. This points to a need for active control. Two different control methodologies are used: (i) the nonlinear Feedback Linearization Technique (FLT) applied to rigid degrees of freedom with flexible generalized coordinates indirectly regulated through coupling; (ii) a synthesis of the FLT and Linear Quadratic Regulator (LQR) to achieve active control of both rigid and flexible degrees of freedom. Furthermore, the FLT is used to track several prescribed trajectories with considerable accuracy. Finally, a two unit ground-based prototype manipulator, designed and constructed by Chu, is used to assess effectiveness of the Proportional-Integral- Derivative (PID) and FLT control procedures in performing several trajectory tracking maneuvers. The study lays a sound foundation for further exploration of this class of novel manipulators.
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