Abstract
A model predictive control approach is proposed for path following of underactuated surface ships with input saturation, parameters uncertainties, and environmental disturbances. An Euler iterative algorithm is used to reduce the calculation amount of model predictive control. The matter of input saturation is addressed naturally and flexibly by taking advantage of model predictive control. The mathematical model group (MMG) model as the internal model improves the control accuracy. A radial basis function neural network is also applied to compensate the total unknowns including parameters uncertainties and environmental disturbances. The numerical simulation results show that the designed controller can force an underactuated ship to follow the desired path accurately in the case of input saturation and time-varying environmental disturbances including wind, current, and wave.
Highlights
Path following of surface ships has been a long-standing control problem that has attracted attention from the control community for many years.[1]
In the study of Shen and Dai,[5] the iterative sliding mode was designed by a hyperbolic tangent function, and both neural network (NN) and reinforced learning were used to inhibit the chattering of the control input
The mathematical model group (MMG) model is used to improve the prediction accuracy as the internal model
Summary
Path following of surface ships has been a long-standing control problem that has attracted attention from the control community for many years.[1]. Few have taken into account the input saturation, whereas the poor control performances or even actuator damages would happen in real implementation if these constraints were neglected in the controller design.[20] Some research studies have pointed out the solutions of the saturation such as introducing an iterative sliding mode theory[5,10,22] or an auxiliary system.[23,24,25] Comparing to the schemes above, the MPC methodology proposed in this article is more natural and flexible[20,26] as just the value of the constrained rudder angle is considered directly in case of solving a quadratic programming (QP)[27] problem. Considering the wind, ocean current and wave disturbances, as well as servo response characteristics, a ship’s MMG model could be expressed as
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
