A Measurement Method Of High-accuracy Information Of Ship's Heave Based On Inertia Measurement

The ship sailing at sea will produce heave movement due to sea breeze,waves and other environmental factors.Real-time and accurate heave motion information can improve the safety and stability when the ship is supplying at sea,the aircraft landing on the ship and the shipborne weapons is launching.Therefore,to accurately measure the heave motion information of the ship is the very important significance.In the process of heave measure information,due to the divergence problem of the inertial vertical channel.Therefore,this paper presents a scheme to add digital IIR high-pass filter.However the IIR digital high-pass filter will bring the system ahead of the phase problem.In this paper,the design of adaptive frequency estimation and delay correction scheme is proposed,in order to achieve real-time measurement of heave information.In this paper,a high accuracy method for measuring the information of ship's heave is designed based on the principle of inertia measurement.The method utilizes the ship attitude output information by the strapdown inertial navigation system and the comparative force information outputted by the vertical accelerometer,adds the IIR digital high-pass filter based on the vertical channel solution of INS to filter out Schuler oscillation and other low-frequency interference information,then design adaptive frequency estimation and delay correction algorithm to solve the problem that IIR digital high-pass filter will bring the ahead phase.To achieve high-precision measurement of heave information.The paper describes the heave motion of a ship.The heave motion of a ship is defined as the motion of the high-frequency line along the axis of the geodetic coordinate system under the action of waves or other special circumstances.The heave motion information includes heave displacement.and vertical velocity.And the paper analyzes the key factors affecting the measurement of heave information are analyzed,including Schuler oscillation,the instability of vertical channel and the phase difference caused by digital high-pass filter.Analyze the causes of adding digital filter and design adaptive frequency estimation and delay correction algorithm separately,complete the digital filter selection and structural design and the overall design of adaptive frequency estimation and delay algorithm.According to the different design of high-pass filter position,we add a third-order filter and three first-order filters to measure the overall scheme of the heave information,and compare and choose the better overall scheme.By analyzing the effect of the design parameters(including filter order,passband cutoff frequency,passband maximum attenuation and stopband minimum attenuation)of the IIR high-pass filter on Filter Performance to Select the optimal design parameters and design the most suitable IIR high-pass filter for heave information measurement And the paper establishs the appropriate simulation signal model,through the computer simulation of the design of the filter filter effect validation.The principle and stability of the Fourier linear combinatorial algorithm are analyzed,and a weighted linear Fourier combinatorial algorithm is designed to estimate the frequency of the filtered signal after lifting.Then an adaptive delay correction algorithm is designed,calculate the amount of lead taken by the IIR high-pass filter based on the estimated frequency of heave motion,bnd by delaying the output and then save the data to be corrected to get real-time heave information.Finally,using the data that are generated by the trajectory generator under various heave motion conditions to do the computer simulation,verify the feasibility of the measurement method of high precision heave information designed in this paper.The simulation results show that the method of high accuracy measurement of heave information based on inertial measurement can achieve high accuracy measurement of heave information...