SEMI-ACTIVE VIBRATION CONTROL FOR OFFSHORE PLATFORMS BASED ON LQG METHOD

The objective of this paper is to mitigate the wave-induced vibration of offshore platform with magneto-rheological (MR) damper. The model of the platform coupled with MR damper is established where the external wave force is approximated with a white noise via a designed filter. Based on Linear Quadratic Gaussian (LQG) method, the optimal control force is determined when taking the measurement noise into account. Semi-active control algorithm is applied to generate the MR damping force by comparing with the optimal control force. Numerical example demonstrates that the semi-active control strategy based on LQG method can reduce the responses of the platform effectively.