Research On Underwater Model Target Location And Attitude Measurement System

With the development of modern technology and the constant prosperity of the world economy,the enhancement of marine science and technology has become an indispensable direction for the military development of all countries.Underwater positioning technology has been widely used in undersea exploration,resource development,military and other fields,real-time position and trajectory can be obtained through the underwater positioning technology for underwater vehicle,attitude measurement so the research of water and water under the positioning of the target has important research significance and practical value.This paper designed the model of water target positioning and attitude measurement system.The system is able to locate the target model at each measurement time,calculate model of target launch position element and to all the surface projection.From the attitude angle,the attitude calculation error of this system is calculated by comparing the measured values of the azimuth attitude instrument.The main work of this paper will be carried out in the signal filtering method,time delay measurement method,underwater positioning method and nonlinear equation solving method.Firstly,the multi-channel signal filtering method is studied in this paper.By comparing the amplitude-frequency and phase-frequency response of the notch filter with series structure and parallel structure,the two filters have the same effect,but the parallel notch filter is faster.Then we studied the method of calculating delay,envelope detection method and quadratic correlation estimation method based on improved linear frequency modulation Z-transform.The envelope detection method has more time-delayed and precise compensation in the calculation,so this method has more advantages.High latency solution accuracy.After solving the time delay of signal transmission,this paper introduced the methods of synchronous positioning and non-synchronous positioning,including spherical intersection and hyperboloid intersection positioning.The positioning solution equations are listed according to their positioning principles.Finally,this paper studied three algorithms for solving nonlinear equations: arithmetic average method of solution,Newton iterative method based on linearized equations,and particle swarm optimization algorithm based on simulated annealing.By comparing the solution of the three algorithms under different SNR,the accuracy shows that the accuracy of the three algorithms is almost the same when the signal-to-noise ratio is high.When the signal-to-noise ratio is relatively low,the simulated annealing-based particle swarm algorithm achieves a higher accuracy of the solution.Finally,Matlab simulation and anechoic pool experiments were performed.The calculated attitude angles in the simulation are almost similar to the real ones.The error angles calculated by the pool experiment are smaller than the azimuth attitude instruments and the root mean square error values are all less than 1°,achieve a higher attitude resolution accuracy.