抄録
In aircrafts and space structures, there are many structural components that can be considered as flexible beams. Vibrations can be harmful to the performance of such structures. In this study, fractional calculus was applied to the vibration suppression of a flexible beam, and the controller parameters were designed. The tuning of the controller parameters has been performed in some previous studies using a trial-and-error approach. However, this tuning process is time-consuming, and there is a risk of destabilization. As an alternative tuning method, a function that implements an optimization algorithm (e.g., the “fmincon” function in MATLAB) has been used in some studies. However, this complicated algorithm can place a heavy load on the computer. Therefore, in this study, a fractional-order controller was designed as an alternative non-trial-and-error approach that is simpler than previously implemented optimization algorithms. This paper proposes a fractional-order controller design method for the vibration suppression of a flexible structure. First, the process of designing a controller to meet the specifications of the Nyquist diagram is explained. An improvement to the design method that allows the attenuation level of a resonant peak to be treated as a specification is then discussed. Numerical simulations performed in this study demonstrate that the proposed fractional-order controller is more robust against spillover instability than the integer-order controller.
