Optimization method for the layout of IMUs in deformation detection system of warship based on genetic algorithm
The deformation of warship will influence the accuracy of angular position about the equipment in the deck. IMUs(Inertial Measurement Unit, laser gyros and accelerometers) are installed on various points of the warship to estimate the deformations. Genetic algorithm is utilized for the optimization of the layout of the IMUs, the fitness function of the genetic algorithm is built by the ship's Modal Assurance Criterion (MAC) matrix. Results show that the Genetic algorithm based method presented in this paper can give an optimal layout of the IMUs for detecting the deformation of the warship.
DECK DEFORMATION MONITORING BASED ON MULTI-IMU FUSION
The precision of the shipborne weapon system was affected greatly by the deck deformation of large size ship.Based on multi-IMU(inertial measuring unit) data fusion,a method was proposed for deck deformation monitoring.The model of deformation measurement was developed using the measured data of a ship.The least square estimation was applied to the analysis of deck deformation.Simulation results show that by processing the output signals of the IMU,it is feasible to monitor the deck deformation real time.The disposition of IMU has a great impact on the accuracy of deformation estimation.The arrangement of IMU on the deck is according to the layout and precision of the shipborne weapon system.
Numerical tools applied to power reactor noise analysis
In order to be able to calculate the space- and frequency-dependent neutron noise in real inhomogeneous systems in two-group theory, a code was developed for the calculation of the Green's function (dynamic transfer function) of such systems. This paper reports on the development as well as the test and application of the numerical tools employed. The code that was developed yields the space-dependence of the fluctuations of the neutron flux induced by fluctuating properties of the medium in the two-group diffusion approximation and in a two-dimensional representation of heterogeneous systems, for both critical systems and non-critical systems with an external source. Some applications of these tools to power reactor noise analysis are then described, including the unfolding of the parameters of the noise source from the induced neutron noise, measured at a few discrete locations throughout the core. Other concrete applications concern the study of the space-dependence of the Decay Ratio in Boiling Water Reactors, the noise-based estimation of the Moderator Temperature Coefficient of reactivity in Pressurized Water Reactors, the modeling of the beam- and shell-mode core-barrel vibrations in Pressurized Water Reactors, and the investigation of the validity of the point-kinetic approximation in subcritical systems driven by an external source. In most of these applications, calculations performed using the code are compared with at-power plant measurements. Power reactor noise analysis applications of the above type, i.e. core monitoring without disturbing plant operation, is of particular interest in the framework of the extensive program of power uprates worldwide.