4. ATTITUDE ESTIMATION AND CONTROL

In order to successfully control the motion of a dynamic system, one must be able to measure its motion, and form a set of equations that model and formulate control inputs to the dynamic system. Since the estimator and the system equations are only models of reality and do not truly measure or represent the motion of the system, the control laws selected to control the system must be robust enough to converge and track to within the desired level of accuracy regardless of these errors.
This chapter describes the physical models chosen to describe the rotational dynamics of Ranger NBV, the methods of state estimation employed to measure its motion, and the control laws selected to guide it.