SATELLITE LAUNCHER ATTITUDE TRACKING AND NORMAL ACCELERATION REGULATION CONTROL LAW

摘要

This work is a comparative study about models and methods to design a control law that tracks a reference attitude and also makes normal acceleration regulation. Three design models and two design methods have been studied, the methods used to design the control law was the linear quadratic method ( LQ ) and the pole placement method. The models used to design the control law was the simplified longitudinal short period model, the complete longitudinal model and an extended model which includes the acceleration equation. From the performed work it has been concluded that the most appropriate model was the complete model and that the most appropriate method was the LQ method. This combination for the design of the control law is able to offer best performance. It also was found that the control law implementation without feedforward can keep the normal acceleration excursions much lower than if implemented with feedforward. Finally it was found that the angle of attack, or normal acceleration feedback is very important to keep the acceleration excursions due to external disturbances.