Dynamic control for LNG carrier with output constraints

Abstract

This paper addresses constrained robust control for dynamic positioning of the Liquefied Natural Gas (LNG) Carrier in side-by-side offloading operations subject to input time delay. During the LNG offloading operation, the relative motions of the multibody system are connected by the LNG offloading arm. To ensure the operation safety, robust control with asymmetric Barrier Lyapunov Function is proposed considering predefined output constraints under the unknown dynamics and external disturbances. In offshore engineering, due to the mechanical effects, the thrusters of the LNG carrier in the presence of time-delay should be investigated to guide the design practice. The predictor-based method is employed to deal with the time delay induced by the control inputs. It is proven that the proposed scheme can guarantee semi-global uniform ultimate boundedness. The performance and feasibility of the proposed control are further verified by simulation studies.

Synchronized tracking control for dynamic positioning vessel

“…In the years of the 1970s of the 20th century, more controllers on optimal theory were proposed and extended later. Later in the 1990s, nonlinear control scheme possibilities for DP began receiving increasing attention; and these include methodologies such as backstepping design, 6 neural network schemes, 7 switching control 8 or sliding mode control (SMC), 9,10 etc. Dynamic control for LNG carriers with output constraints provides a backstepping approach to regulate and optimize the behavior of these specialized vessels during LNG transportation, allowing for safe and efficient operations while considering limitations on key output variables 6 .…”

“…Later in the 1990s, nonlinear control scheme possibilities for DP began receiving increasing attention; and these include methodologies such as backstepping design, 6 neural network schemes, 7 switching control 8 or sliding mode control (SMC), 9,10 etc. Dynamic control for LNG carriers with output constraints provides a backstepping approach to regulate and optimize the behavior of these specialized vessels during LNG transportation, allowing for safe and efficient operations while considering limitations on key output variables 6 . The switching control perspective on the offshore construction scenario of heavy‐lift vessels emphasizes the need for adaptive and robust control strategies that can seamlessly transition between different modes and effectively address the challenges encountered during the no‐load, mooring, and free‐hanging phases 8 .…”

“…Dynamic control for LNG carriers with output constraints provides a backstepping approach to regulate and optimize the behavior of these specialized vessels during LNG transportation, allowing for safe and efficient operations while considering limitations on key output variables. 6 The switching control perspective on the offshore construction scenario of heavy-lift vessels emphasizes the need for adaptive and robust control strategies that can seamlessly transition between different modes and effectively address the challenges encountered during the no-load, mooring, and free-hanging phases. 8 Additionally, sliding mode control, as another more advanced and also reliable technique for addressing the DP challenge, has been observed to attain encouraging results in marine control applications.…”

Collision and obstacle avoidance for agents based on velocity programming in unknown environments under kinematical constraints

“…So, the arousing problem is how to complete collision avoidance with partial data in clustered areas. Besides, constrained agents [11][12][13] own the problem of mutual restrictions between the velocity and angular speed, which increases the difficulties in motion control while conducting collision avoidance. In terms of collision avoidance, collaborations among agents are expected in many papers since it is better to realize navigation with predesigned formation.…”