Mehdigholi H, Azizi Yegejeh M, Seif M S. Modeling the forward accelerated motion of planing craft and its optimal control to minimize the time to reach final speed. Modares Mechanical Engineering 2016; 15 (11) :263-274
URL:
http://mme.modares.ac.ir/article-15-2664-en.html
Abstract: (5711 Views)
It is of crucial importance to adjust the trim angle properly during the forward acceleration of a planing craft in cases such as sport competitions and military missions. In these applications, the goal of trim adjustment is to reach the final cruising speed as soon as possible. Present study tries to answer this question: How the angles of the drive system and/or a control element should be changed during acceleration phase in order that the craft can reach to its final speed in the minimum possible time? This is an optimal control problem with the drive and control element angles as its control variables. To solve such problem, a 3-DOF dynamic model is developed based on the theoretical and empirical methods. Both propeller operation and the engine are taken into account for the propulsion system. Then, the solution algorithm of time-optimal control problem is explained according to an indirect method. Results for a planing mono-hull with two different weight distributions show a similarity in trend between the optimal solution for control variables and the hull instantaneous trim angle. As the second case study, the solution for an aerodynamically alleviated racing catamaran is presented.
Article Type:
Research Article |
Subject:
Marine Structures Received: 2015/05/26 | Accepted: 2015/07/22 | Published: 2016/01/30