Dynamic positioning control method based on UKF and constraint model predictive control

Abstract

The invention provides a dynamic positioning control method based on UKF (Unscented Kalman Filtering) and constraint model predictive control. The method includes the following steps: obtaining the position and course information of a ship through a sensor; receiving the measured information by a UKF filter, filtering noise interference and wave high frequency oscillation components in the information, and carrying out state estimation for unmeasured states; receiving a low frequency state estimated value of the UKF filter by a model predictive controller and taking the low frequency state estimated value as an initial condition for future dynamic prediction, considering system thruster constraint and operating area constraint online, carrying out optimal solving of a target function, generating an optimal control instruction and transmitting the instruction to the controlled ship, thereby controlling the ship to keep the set position and course. The method avoids frequent movements ofa thruster, reduces wearing and energy consumption of the thruster, improves the control effect and stability of model predictive control, and has high engineering utilization values.

Description

technical field [0001] The invention relates to the field of ship dynamic positioning control, in particular to a ship dynamic positioning control method based on UKF filtering and constraint model predictive control. Background technique [0002] Ship dynamic positioning (Dynamic Positioning, DP) is a key technology for deep sea development. The dynamic positioning system has strong adaptability to extremely deep waters and harsh sea conditions, and has strong positioning capabilities, so it is widely used in deep-sea oil drilling platforms, ocean research vessels, semi-submersible vessels, underwater submersibles, marine supply / handling ships, seabed Cable laying, sea salvage and lifesaving, and military ships' fixed point, tracking, line following or tracking control. [0003] The core of the dynamic positioning system is a control system composed of computers, and the key to the control system is the controller. As an intelligent computer control algorithm, model predi...

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Problems solved by technology

[0005] Wang Yuanhui et al. (Wang Yuanhui, Shi Xiaocheng, Bian Xinqian. Ship Dynamic Positioning Constrained Control Based on Model Predictive Control. Ship Engineering, 2007,29(3):22-25) did not consider the state estimation when designing the model predictive controller and filtering, the control effect will be affected when the state is not measurable

Wang Gang et al. (Wang Gang, Li Wenhua, Chen Haiquan, Lin Benjie. Predictive control of ship dynamic positioning model based on state estimator. Journal of Dalian Maritime University, 2015, 41(3): 24-28) considered the estimation of unmeasurable state , but the design of the filter is not considered, the noise in the measurement signal and the existence of high-frequency motion of the ship will cause the thruster to move frequently and cause unnecessary energy consumption and wear

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