PID and PI – sliding mode controller design for a fin actuation system

In the thesis study, PID and PI-Sliding Mode Controller are designed and then tested experimentally as two different controller types for the control of a fin actuation system. The coefficients and parameters of the equation of motion of the fin actuation system are obtained from the CAD model of the fin actuation system and the technical datasheet of the electric motor which is used in the fin actuation system. In addition to the coefficients and parameters, the nonlinear aerodynamic load model is included in the system mathematical model as a disturbance input. In the thesis study, the mathematical model of the system is derived, and then the previously determined coefficients and parameters are used in the model. In the controller design part, firstly, the PID controller is designed and the simulations are performed. Secondly, PI-Sliding Mode Controller is designed and the simulations are performed. Different sliding mode controller reaching law approaches such as constant rate reaching law, exponential reaching law, power rate reaching law and classical reaching law are explored and among these reaching law approaches, the power rate reaching law type sliding mode controller is designed and applied. After the simulation studies, the controllers are used for the experimental studies. For the experimental studies, additional tests are performed to improve the performance of the controllers. The controller coefficients used in the simulation studies are tuned for the experimental studies due to the noisy signals encountered in the experimental system. Moreover, low pass filters are used to suppress the noise effects in the experimental system. In the experimental studies, the fin actuation control system is tested under different aerodynamic load conditions and without aerodynamic load conditions to simulate the real working conditions. The experimental test studies reveal the validity of the designed controller for practical implementations.