| Analysis of the attitude dynamics of a spacecraft is necessary for its successful operation. Recent research has focussed on the object-oriented analysis and design for generating and solving the complex nonlinear dynamic equations of motion of a multibody space system. In this thesis, an effort has been made to develop objects that can be combined to formulate the complete dynamic equations of a spacecraft containing reaction wheels. In order to generate the mathematical model and dynamical equations of the multibody system, a variation of the Lagrange's method has been used, along with the concept of Natural Orthogonal Complement, in order to eliminate the kinematic constraint force and moments.; The designed objects would be part of a multibody system software package that could simulate the complex dynamics of a spacecraft containing reaction wheels and any arbitrary configuration of connected bodies. The objects have been designed such that the spin rate of the wheels may be specified as a constant nominal rate, or as any function of time, or in the form of a P.I.D. control law, wherein the wheel spin rate is a function of the body quaternion of the motherbody. The accuracy, versatility, and adaptability of the designed objects have been illustrated with numerous examples and compared with results obtained using standard procedure. Maneuvers have also been simulated on the designed model and compared with available spacecraft data in order to substantiate the authenticity of the designed objects. |
