Semi-Active Control of Structural Systems With an Output Emulation Method Based on a Quadratic Error Function

Abstract

A semi-active control method based on a controlled output of a targeted active control law is proposed in the study. As a conventional method, a semi-active control law based on the targeted active control input, e.g., a clipped optimal control and its related methods, is widely used for the vibration control of structural systems. In the present study, on the other hand, the controlled output of the targeted active control law is used as the reference of the semi-active control. The semi-active control strategy is referred to as “output emulation approach” and the authors showed a method based on the output emulation approach based on the predicted controlled output by assuming the targeted active control as the LQ optimal control law in the previous study. In this paper, a new output emulation semi-active control method with a quadratic error function between the controlled output signal of the semi-active control system and that of the targeted active control system. The semi-active control law minimizing the quadratic error function is obtained as a bang-bang type switching of the variable damping coefficient of the semi-active control device. The targeted active control law is defined as a state-space control with a constraint on the closed-loop pole placement. Design parameters to determine the region of the pole placement of the targeted active control system are adjusted so that the semi-active control based on the proposed output emulation approach is optimized. The effectiveness of the proposed approach is shown with a simulation example.