Estimation and compensation for hull deformation is an indispensable step for the ship to establish a unified space attitude. The existing hull deformation measurement methods are dependent on the pre-established deformation model, and an inaccurate deformation model will reduce the deformation estimation accuracy. To solve this problem, a hull deformation estimation method without deformation model is proposed in this article, which utilizes the neural network to fit the hull deformation. To train the neural network online, connection weights of the neural network are regarded as system state variables which can be estimated by the Unscented Kalman Filter. Simultaneously, considering the time delay problem of inertial data, a time delay compensation method based on the quaternion attitude matrix is proposed. The simulation results show that the proposed method can obtain high estimation accuracy without any deformation model even when the inertial data are asynchronous.

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Studies show that finite control set model predictive control (FCS MPC) is robust for single‐phase inverters in sinusoidal current tracking. That is, even if there are parameter uncertainties in inverter system, MPC can achieve accepted control performance. However, it is still necessary to reconstruct the unknown parameters. On the one hand, an accurate model is helpful to get better performance. On the other hand, accurate parameters can be used to determine the boundary of current reference. Relying on the strong robustness, under unknown offset free MPC (UOF MPC) frame, this study characterises the deviation of the parameters as an unknown sinusoidal signal, and designs two observers to reconstruct it. One is a linear observer for instantaneous value observation. The other is a time‐varying observer for the amplitude and phase identification. Its convergence is guaranteed by the Lyapunov function and the Laselle invariant set principle. All the proposed methods are validated by a rapid control prototype based on Labview FPGA platform. Moreover, experiments show that even if the reference exceeds the real maximum tracking current boundary, the proposed observers work well with accurate parameters identified and the reference can be adjusted online to avoid distorted current tracking.

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