Online Adaptive Vibration Control and Fault Diagnosis based on Identification for Offshore Platforms

This paper investigates the vibration suppression and fault diagnosis problem of jacket-type offshore platforms with uncertainties and time delay. Firstly, through a model transformation, the original continuous-time model is transformed into an identifiable differential form. Secondly, according to the model-based theory, the fault diagnosis problem can be regarded as a parameter estimation issue. The Self-adjusting forgetting factor system identification algorithm is adopted to estimate the time-varying system parameter. By computing the residuals of the parameters in the fault-free model and the estimated parameters, we can detect the faults. Thirdly, we propose an adaptive controller to overcome the parameter uncertainty by using system identification algorithm. The controller parameters can converge to a new value as the physical parameters of offshore platforms change. The simulation results demonstrate the feasibility and efficiency of the design presented in this paper for eliminating vibration and fault diagnosis.