Research On Dynamic Detection Technology For Deck Deformation Of Large Ships

In this paper,the dynamic measurement of the deflection of large ships' deck is studied.The purpose is to solve the problem that the original straight deck is deformed due to natural factors such as sea waves,sea breeze,and the influence of ship motion.The inertial measurement method combining the main inertial navigation system(INS)and the sub-inertial navigation system(SINS)is used to dynamically detect the deformation of the deck,find the position beyond the design index,and carry out corresponding maintenance and reinforcement in time.Therefore,the measurement accuracy of the equipment,launch accuracy of weapon systems on the deck,and the safety of the carrier's take-off and landing are guaranteed.According to the principle of inertial navigation,the ship motion reference model and the deck deformation sliding detection model are established.An INS is fixed on the ship to estimate the attitude change of the ship as a benchmark.At the same time,a SINS is placed on the deck so that it can slide smoothly along the detection trajectory to detect the deformation of any trajectory on the deck.Before the mechanical programming calculation,the gyro drift model is established.A dynamic filtering algorithm based on wavelet combined with Kalman filter is proposed to reduce the noise and eliminate the outliers.The auto-regressive moving average model(ARMA)is used to simulate the gyro drift,and then the wavelet filtering combined with Kalman filtering is used to de-noise and de-field.The gyro drift is processed to verify the effectiveness of the algorithm.Then the INS and SINS are separately modeled,and the simulation data are processed by the proposed filtering algorithm,and then the frequency spectrum analysis is performed.The acquired data are used to calculate the curvature and torsion parameters of the trajectory by differential geometry and locate at the same time.Through the simulation analysis,the conclusion is consistent with the expectation.The dynamic inertial measurement method combining INS and SINS can quickly give the motion parameters of the carrier,and can dynamically calculate the curvature andtorsion of the deck.The change of deck's torsion is greater than that of curvature,which is due to the fact that the deck is more likely to be distorted when the ship is sailing in the sea.The simulation results show that the dynamic filtering algorithm of wavelet combined with Kalman filter plays a significant role in improving the detection accuracy of deck deformation.Finally,through the actual detection of different trajectories and multiple groups on the 1:800 "Kuznetsov" aircraft carrier model,the operability,flexibility and rapidity of the dynamic inertial measurement method combining INS and SINS are verified.It shows that this method is feasible in experiment and engineering application.