Object-oriented modelling of spacecraft dynamics: tools and case studies

The development process for spacecraft control systems relies heavily on modelling and simulation tools for spacecraft dynamics. For this reason, there is a strong need for adequate design tools in order to cope efficiently with tight budget and time constraints for space missions. In this chapter the main issues related to the modelling and simulation of satellite dynamics for control purposes are first discussed and an object-oriented modelling framework, implemented as a Modelica library, is then presented. The proposed tools enable a unified approach to a range of problems spanning from initial mission design and actuator sizing phases, down to detailed closed-loop simulation of the control system, including realistic models of sensors and actuators. It also promotes the reuse of modelling knowledge among similar missions, thus minimizing the design effort for any new project. The proposed framework and the Modelica library are demonstrated by means of two case studies.