The deployment/retrieval control of a tethered subsatellite connected through an elastic tether to a main body is studied. The dynamical model of the tether is a continuum, and the effect of tether elasticity is taken into account. Large deflection theory is adopted to formulate the strain of tether. The motion is described by nonlinear, partial differential, and time-varying equations and is treated directly without using any approximation of the modal analysis. The mission-function control algorithm is applied to the deployment/retrieval control of the subsatellite connected through the elastic tether. Results of numerical simulation show that the present control law works quite well for deployment/retrieval control of the subsatellite, and that the elastic vibrations of the tether are suppressed satisfactorily.
Ministry of the Environment of Japan started the national demonstration project of Floating Offshore Wind Turbine (FOWT) in 2010 FY. In this project two SPARs with different scales are used. The first half-sized model, supporting a 100kW wind turbine, was installed in 2012 and is currently in operation. It is characteristic that the floater has a hybrid structure, i.e., the upper part is constructed of steel and the lower part of pre-stressed concrete and that the turbine is downwind type of horizontal axis.
The FOWT is equipped with many sensors for measuring motions of 6 DOF, the strain of the steel / concrete parts and other factors. In this paper the measuring system is presented. In September 2012, the FOWT was attacked by a huge typhoon and it survived, although the measured wave height exceeded the designed value. The measured record of the floater in the storm is also presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.