Towards Digital Computer Simulation of the Dynamics of Flexible Spacecraft

摘要

A method based on a sequence of modified modal transformations for numerical simulation of the dynamics of flexible spacecraft equipped with actuators and sensors was developed. The spacecraft assembly is treated as a sampled data system, characterized by locally constant inputs and by outputs at discrete times. The result consists of a system of exact difference equations, which describes the transition of the spacecraft assembly state from one point in time to the next. In this manner, the usual numerical integration of the differential equations of the spacecraft assembly is replaced by exact, numerical, discrete propagation with difference equations. The associated time interval is determined mainly by measurement times, control update times, and measurement and system noise simulation requirements.