Crisis control: Preventing chaos-induced capsizing of a ship.

Responses of many man-made systems, such as ships or oil-drilling platforms, when subject to irregularly time varying environments, can be described by irregularly driven dynamical systems. Consequently, failures of such systems (e.g., capsize of a ship or collapse of a platform), under increasingly severe environmental conditions, come about when the system state escapes from a destroyed chaotic attractor located in some favorable region of the phase space. In this paper we propose a control strategy, based on a previous method of chaos control, which can prevent such failures from taking place. The key feature of our strategy is the incorporation of prediction of the evolution of the environment. This makes possible effective operation of the control even when the temporal behavior of the environment has substantial irregularity. We illustrate the ideas using ship capsizing as an example.