System identification is a quintessential measure for real-time analysis on kinematic characteristics for deep-sea mining vehicle, and thus to enhance the control performance and testing efficiency. In this study, the...System identification is a quintessential measure for real-time analysis on kinematic characteristics for deep-sea mining vehicle, and thus to enhance the control performance and testing efficiency. In this study, the system identification algorithm, recursive least square method with instrumental variables(IV-RLS), is tailored to model ‘Pioneer I’, a deep-sea mining vehicle which recently completed a 1305-meter-deep sea trial in the Xisha area of the South China Sea in August, 2021. The algorithm operates on the sensor data collected from the trial to obtain the vehicle’s kinematic model and accordingly design the parameter self-tuning controller. The performances demonstrate the accuracy of the model, and prove its generalization capability. With this model, the optimal controller has been designed, the control parameters have been self-tuned, and the response time and robustness of the system have been optimized,which validates the high efficiency on digital modelling for precision control of deep-sea mining vehicles.展开更多
The multi-body system has been a popular form for offshore operations in terms of high efficiency.The wind effects are crucial which directly affect the relative positions of floating bodies and operating security.In ...The multi-body system has been a popular form for offshore operations in terms of high efficiency.The wind effects are crucial which directly affect the relative positions of floating bodies and operating security.In this study,the aerodynamic characteristics for two coupled semi-submersibles were analyzed in a wind tunnel to fill the gaps in literature related to the wind sheltering on offshore platforms.The influences of separation distance were also investigated.According to the results,substantial shielding effects were observed and wind forces on the shielded vessel decreased dramatically:a reduction in the transverse force could be up to 74%.Moreover,the longitudinal wind load was amplified by the platform abreast in a side-by-side configuration.As expected,the interference level became more pronounced with a decreasing separation distance.For cases in which wind interaction decayed rapidly with distance,logarithmic functions were preferable for describing the relationship between them.Whereas linear fitting was reasonable for the transverse wind force when there was still evident sheltering at a quite large distance.The length of shielding area was another important factor that there was approximately a linear relationship between it and the shielding level for two platforms in close proximity at various wind attack angles.Based on the two parameters,a preliminary wind loads estimation method considering shielding effects was proposed.This approach can aid the industry to have a qualitative assessment of wind sheltering especially at early stages.展开更多
基金financially supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(Grant No.2021JJLH0078)the Science and Technology Commission of Shanghai Municipality (Grant No.19DZ1207300)the Major Projects of Strategic Emerging Industries in Shanghai。
文摘System identification is a quintessential measure for real-time analysis on kinematic characteristics for deep-sea mining vehicle, and thus to enhance the control performance and testing efficiency. In this study, the system identification algorithm, recursive least square method with instrumental variables(IV-RLS), is tailored to model ‘Pioneer I’, a deep-sea mining vehicle which recently completed a 1305-meter-deep sea trial in the Xisha area of the South China Sea in August, 2021. The algorithm operates on the sensor data collected from the trial to obtain the vehicle’s kinematic model and accordingly design the parameter self-tuning controller. The performances demonstrate the accuracy of the model, and prove its generalization capability. With this model, the optimal controller has been designed, the control parameters have been self-tuned, and the response time and robustness of the system have been optimized,which validates the high efficiency on digital modelling for precision control of deep-sea mining vehicles.
基金the Ministry of Industry and Information Technology of China(Grant No.[2016]546)and Shanghai Innovation Action Plan of Science and Technology(Grant No.19DZ1207300).
文摘The multi-body system has been a popular form for offshore operations in terms of high efficiency.The wind effects are crucial which directly affect the relative positions of floating bodies and operating security.In this study,the aerodynamic characteristics for two coupled semi-submersibles were analyzed in a wind tunnel to fill the gaps in literature related to the wind sheltering on offshore platforms.The influences of separation distance were also investigated.According to the results,substantial shielding effects were observed and wind forces on the shielded vessel decreased dramatically:a reduction in the transverse force could be up to 74%.Moreover,the longitudinal wind load was amplified by the platform abreast in a side-by-side configuration.As expected,the interference level became more pronounced with a decreasing separation distance.For cases in which wind interaction decayed rapidly with distance,logarithmic functions were preferable for describing the relationship between them.Whereas linear fitting was reasonable for the transverse wind force when there was still evident sheltering at a quite large distance.The length of shielding area was another important factor that there was approximately a linear relationship between it and the shielding level for two platforms in close proximity at various wind attack angles.Based on the two parameters,a preliminary wind loads estimation method considering shielding effects was proposed.This approach can aid the industry to have a qualitative assessment of wind sheltering especially at early stages.
