eng Science and Education Publishing International Journal of Physics 2333-4576 2017-01-09 4 6 181 186 10.12691/ijp-4-6-5 IJP2016465 article Hassan Ghassemi gasemi@aut.ac.ir 1 Hamid Malekizade 1 Arash Ashrafi 1 Department of Maritime Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran The aim of this study is to diminish the roll motion of the fishing vessel using fin-roll stabilizer. In this regard, lift coefficient of the fin and the hydrodynamic coefficients of the roll equation are calculated by empirical formulas. In effect, constrained LQR (Linear Quadratic Regulator) controller is designed and used to control the roll motion in the presence of operational constraints of fin's actuator. In order to boost the validity of our results, the performance of this controller is compared with a conventional PID (Proportional-Integral-Derivative) controller. Finally, simulation results indicate the significant amount of reduction in roll amplitude. http://pubs.sciepub.com/ijp/4/6/5/ijp-4-6-5.pdf PID controller fishing vessel fin roll stabilizer