Abstract Motion based wave inference allows the estimation of the directional sea spectrum from the measured motions of a vessel. Solving the resulting inverse problem is challenging as it is often ill-posed; moreover, inaccuracies related to the linearity hypothesis behind estimated platform response functions (RAOs) may result in misleading estimations of the sea states. This work discusses how these inaccuracies affect the estimations obtained by means of a Bayesian motion based wave inference method (VMB). For this purpose, an heuristic correction, accounting for the non-linearity related inaccuracies of the estimated RAOs, is included in an expanded Bayesian inference approach. Then, the resulting inference model is verified by means of a comparison between the outputs of this novel approach and those obtained without accounting for nonlinearity related inaccuracies in the RAOs. This assessment has been carried out using the data measured through dedicated model scale experiments of the Equinor’s Asgard-B semisubmersible oil processing platform. The results attested that improvements are obtained if the linearly related RAOs inaccuracies are taken into account in the VMB, especially for the sea conditions that excite the non-linear responses of the semisubmersible platform adopted as motion-based wave sensor.

中文翻译：

---

一种考虑非线性相关的运动 RAO 不准确性的贝叶斯波推理方法

摘要 基于运动的波浪推理允许从测量的船舶运动中估计定向海洋频谱。解决由此产生的逆问题具有挑战性，因为它通常是不适定的；此外，与估计的平台响应函数 (RAO) 背后的线性假设相关的不准确可能会导致对海况的误导性估计。这项工作讨论了这些不准确性如何影响通过基于贝叶斯运动的波浪推理方法 (VMB) 获得的估计。为此，在扩展的贝叶斯推理方法中包含了启发式校正，用于解释估计 RAO 的非线性相关不准确度。然后，通过将这种新颖方法的输出与未考虑 RAO 中非线性相关的不准确度而获得的输出进行比较，可以验证由此产生的推理模型。该评估是使用通过 Equinor 的 Asgard-B 半潜式石油加工平台的专用模型规模实验测量的数据进行的。结果证明，如果在 VMB 中考虑线性相关的 RAO 不准确性，则可以获得改进，特别是对于激发作为基于运动的波浪传感器的半潜式平台非线性响应的海况。