Satellite Attitude Control Based On Fuzzy Logic Control

With the development of the Aerospace Technology, the requirements for Satellite Attitude Control are getting more and more complex. In order to study new methods used in Satellite Attitude Control, this thesis presents three controllers: an I/O Linearized PID Controller, a Mamdani type Fuzzy Controller and an I/O Linearized Adaptive Fuzzy Controller, and compares their performances in simulation taking the Attitude Maneuver Control as example. Models of the three-axis stabilized Attitude Control Systems of a rigid satellite and a flexible satellite with a pair of solar arrays are set up. At first, a traditional and widely used controller, I/O Linearized PID controller, is presented. As a mature technology, the PID control is used in most of the onboard satellites. The design of the controller is regular and strongly dependent on the satellite's math model. It has very good performances under small disturbance and small variance of the moment of inertia. But its performance gets bad when the variance of the moment of inertia is bigger. Utilizing language information and experiences, the thesis develops a typical Mamdani type Fuzzy Controller. Comparing with the I/O Linearized PID controller, the Fuzzy Controller has the stronger robustness quality, it performs well even when the variance of the moment of inertia is very big. Incorporate the I/O Linearized theory into the Adaptive Fuzzy Control, the author finally develops an I/O Linearized Adaptive Fuzzy Controller. Simulation results show its high quality that is equivalent to the Mamdani type Fuzzy Controller. It exceeds the Mamdani type Fuzzy Controller in two aspects: First, using adaptive rules, the I/O Linearized Adaptive Fuzzy Controller can get good capability with only very limited language information. Second, the control law is based on a Lyapunov Function, so the stability of the system is guaranteed. From all that discussed, we can conclude that the design of the I/O Linearized Adaptive Fuzzy Controller is very agile and not strongly dependent on the satellite's math model, and the control system has a strong robustness quality. In the field of Satellite Attitude Control, which requires a very high reliability, the application of the I/O Linearized Adaptive Fuzzy Control is expected to be valuable.