Response control of a floating airport in heading waves with output saturation

This paper presents a nonlinear control strategy to stabilize the response of a floating platform in waves. The floating platform consists of multiple floating modules connected in sequence with flexible connectors. A nonlinear dynamic model with a number of controllers is developed for the stability control of the chain-shape floating structure. The backstepping method in conjunction with the Lyapunov stability criteria is proposed to derive the control law for each of the control actuators where the actuator forces are limited with output saturation. The numerical experiments illustrate the feasibility and effectiveness of the control strategy in various conditions of heading waves. The performance of the control method is discussed, especially associated with the saturated output.

Some Aspects of Mega-Floating Airport Design and Production

Mega-Floating Airports (MFA) are unique and complex offshore transport system components that emerged as a consequence of tremendous land price increase in the vicinity of very large coastal cities. An overview of MFAs design and production aspects is presented within this paper including design concept, model tests and full scale measurement, air transport analysis, infrastructure, main particulars and structure, wave breaker, hydroelastic analysis due to wave load and airplane moving mass, mooring analysis, production technology and environmental aspects. MFA dynamic response due to airplane load is emphasized as the most challenging problem. Theoretical outline as well as a realistic illustrative numerical example are presented.

Structural response of a floating runway excited by the taking off of an airplane

When designing a floating airport we need to address the structural response both by ocean waves and dynamic loads such as the landing / take off of an airplane. Since such problems are not conducive to physical modeling and experimental validation due to their size and speeds involved, numerical analysis is an accepted norm. However conventional means to study structural responses using a three dimensional runway with time varying dynamic loads is numerically difficult and time consuming. The analysis is made simpler by assuming the airport to be a simple, infinitely long beam, given by a one dimensional Timoshenko-Mindlin plate equation, in contact with the water surface. In developing this expression, a Fourier transformation in space in wave number domain is utilized rather than using the wave propagation method to reduce the analysis to a substructure. On analyzing, the structural response is seen as local peaks emanating from the point of load application which moves in a curvilinear path with increasing speed of the airplane. The location of these peaks a priori is however not feasible.DOI: http://dx.doi.org/10.3329/jname.v11i2.19167