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Abstract. The studies on the so-called smart materials have grown in the last years due to the diverse possibilities that these materials can provide. These types of materials have the ability to respond to an external excitation, altering its physical form, and being able to be considered as actuators. Among these materials are the Shape Memory Alloys (SMA), several metal alloys that are able to memorize a shape and recover it after a deformation through an increase of its thermal energy. In this paper, an actuator consisting of an SMA wire is used to attenuate the vibration and Sommerfeld effect of a non-ideal type oscillator. The temperature control of the actuator was carried out through the application of an electric current in the wire. Results are presented for different currents, with the objective of investigating the temperature variation for vibration control applications. The results showed that it is possible to apply SMA actuators to the attenuation of the Sommerfeld Effect as well as in the reduction of the total vibration of the system.

This paper presents the design of the LQR (Linear Quadratic Regulator) and SDRE (State-Dependent Riccati Equation) controllers for the flight control of the F-8 Crusader aircraft considering the nonlinear model of longitudinal movement of the aircraft.  Numerical results and analysis demonstrate that the designed controllers can lead to significant improvements in the aircraft's performance, ensuring stability in a large range of attack angle situations. When applied in flight conditions with an angle of attack above the stall situation and influenced by the gust model, it was demonstrated that the LQR and SDRE controllers were able to smooth the flight response maintaining conditions in balance for an angle of attack up to 56% above stall angle.  However, for even more difficult situations, with angles of attack up to 76% above the stall angle, only the SDRE controller proved to be efficient and reliable in recovering the aircraft to its stable flight configuration.

This study aims to present a PI-Fuzzy and PID-Fuzzy design to control the position while maintaining the balance of an inverted pendulumsystem. This type of system is well known for its challenge in carrying out the control and its similarities and applications in other systems, such as transport vehicles and robots. Thus, being a famous and important system to be used as a control benchmark. Nonlinear dynamic equations for the inverted pendulum where obtained through the Lagrange formulation. An adaptive PI-Fuzzy and PID-Fuzzy controller was designed and implemented on the nonlinear model. The final results demonstrate a great increase in performance, both on displacement and dynamics balance, when compared to the classic PI and PID controllers, especially when in the presence of parametric changes in the system