نوع مقاله : مقاله پژوهشی
نویسندگان
دانشکده مهندسی هوافضا، دانشگاه صنعتی شریف
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
One of the critical problems in controlling mechanical systems is the structural interactions. Obviously, all the bodies have elastic behavior, and rigidity is assumed to reduce the modeling complexity, which is not applicable to many situations. For example, gravity gradient booms and solar panels used in satellites have considerably large deflections relative to their basements. These such systems are recognized as Coupled Rigid-Flexible structures. In these cases, it is possible to consider the more flexible part of the structure as elastic and the other as rigid. With the development of fractional order calculus and more accurate modeling of physical phenomena, the problem of controlling these systems by considering the uncertainties in the system will become necessary and inevitable. In this paper, the fractional order transfer function model of a satellite with coupled rigid-flexible structures is used as the reference work of the research. The sliding mode control method, which is one of the robust control methods, has been used to control this dynamic system. It is not possible to design a sliding mode controller directly for a transfer function. For this reason, a fractional order pseudo-state space model is first obtained from the fractional order transfer function model. Then, a controller is designed for it. On the other hand, considering the dynamics of the system is used in the design process of the sliding mode controller and proving its stability. Since the state space model is fractional, it is clear that the integer order sliding surface cannot be used. Therefore, the fractional sliding surface has been used for this purpose. The results show that in the presence of considerable uncertainties in each of the four parameters of the dynamical system, and considering the effects of sensor noise and the saturation element for the control signal, this controller can overcome it and follow the reference signal.
کلیدواژهها [English]