A model predictive vertical motion control of a passenger ship

Abstract

In this study, the design problem of a Model Predictive Controller (MPC) for attenuation of vertical motions of a passenger ship which is subject to irregular wave excitations is investigated. The proposed design considers actuator amplitude and rate saturation phenomenon. The motion control system of the ship utilises a pair of active stabilizing fins mounted to the head and tail. First, irregular long crested head waves are implemented by a well-established randomization theory in order to find heave force and pitch moment at F n = 0.40 and F n = 0.50 in the time domain. Then, a two-degree-of-freedom mathematical model, in which pitch and heave motions are coupled with the approximation of convolution integrals is solved to obtain the uncontrolled motions and accelerations of the ship. Finally, considering the physical amplitude and rate limitations of the active fin mechanism, an MPC design is proposed to obtain a practically applicable state-feedback control law for attenuating vertical motion of a passenger ship. The performance of the MPC is also compared with an elipsoid based H ∞ controller. An extensive amount of simulation studies are presented at the end to illustrate the effectiveness of the proposed approach.

Robust disturbance rejection for discrete-time systems having Magnitude and rate bounded inputs

“…Finally, applying a congruence transformation on (21) by using P = P T 0 and the Schur complement formula, (21) can be represented by the LMI (7).…”

“…Details about these incidents can be found in the references [1], [2], [3] and [4]. Other examples of practical problems in which the magnitude and rate bounded actuators create a source of performance degradation and instability can be listed as the control of jet engine compressors [5], general reaction processes having sluggish actuators [6] and stabilisation of ships using active fins [7]. Therefore, designing effective controllers for systems having hard limitations on their actuators and subject to uncertainties and disturbances has been a fundamental problem for the control community for several decades [8], [9].…”

Experimental and numerical investigation on control strategies for heave and pitch motion reduction of a catamaran

“…In their results, the pitch motion was decreased by 41.3% in regular waves and 32.4% in irregular waves. Kucukdemiral et al 29 compared model predictive control (MPC) compared with H ∞ control for the heave and pitch motion control of a ship. Their simulation results verified that the MPC algorithm performed better than the H ∞ control algorithms and noticeably reduced the heave and pitch motions.…”

Study on vertical motion reduction of a trimaran based on collaborative controlled appendages

“…Adaptive fuzzy fault-tolerant control, fuzzy dynamic surface control, and fuzzy backstepping sliding mode control were also applied in the controller design for marine applications. 13 –15 Model predictive vertical control of a passenger ship was studied by Kucukdemiral et al 16 They designed a controller based on model predictive control. The controller has good performance compared to the other control methods ( H small∞ control).…”