A Ship Personnel Cabin Positioning System Based On RFID And Inertial Positioning

China is a maritime power,and more and more people are engaged in maritime operations,putting forward higher requirements for the management of ship personnel.This article combines the current situation of scarce dynamic management systems for ship personnel,and takes river and sea operations as the background.Based on RFID technology and inertial technology,a cabin personnel positioning system is designed,providing a new solution for the informationization of ship personnel management.The main research content is as follows:(1)To solve the problem that the RSSI value fluctuates and has Outlier in the actual ranging,the loss factor n and path loss A in the log Normal distribution ranging model are not clear in the ship environment,the common methods of RFID positioning anchor node utilization is low,and the impact of distance on the positioning results is not considered,the following solutions are proposed: determine the distribution of RSSI values according to the characteristics of the Gaussian function for data filtering;Using linear regression to establish an equation system between RSSI values and n and A to obtain their optimal values;Use a group weighted centroid localization method to fully utilize anchor nodes and reduce the impact of distance on localization results.In response to the problems of large acceleration detection fluctuations and pseudo gait in traditional PDR algorithm gait detection,few variables in step size estimation model,large jump amplitude of direction estimation magnetic declination,and significant error accumulation,the following solution is proposed: using sliding window average preprocessing data combined with multi threshold constraints for gait detection;Add height,step frequency,and peak/valley acceleration variables to the step size model and calculate their linear parameters;Calculate the relationship between the rotation angle measured by the gyroscope and the angle between IMU and geomagnetic north using the relationship coefficient,and establish a model.(2)Aiming at the problem of large fluctuation of RFID positioning and divergence of inertial positioning error with time,Kalman filter is designed,and Equation of state and observation equation are established for fusion positioning.In order to make the trajectory displayed on the upper computer more accurate,a fusion positioning combined with map matching method is proposed to establish a map model of the monitoring area,and a marker point detection method is used to correct the position and direction of personnel.(3)Complete hardware design based on theoretical and algorithmic research.Determine functions and design principles based on system requirements,and develop an overall plan.Select key components,design the main control,minimum system,peripheral,RF chip,IMU,communication and other circuits,and finally provide a physical diagram of the system after assembly.(4)Conduct actual measurements on the assembled system.Select the venue and arrange the hardware,design experiments to test the system performance,including RFID/inertial fusion positioning and single inertial positioning,combined map matching and non combined map matching comparative experiments.The experimental personnel walked along the prescribed route,used different positioning algorithms for detection,and analyzed the personnel trajectory displayed on the upper computer.The experimental results showed that this system can provide more accurate and stable personnel positioning,which has practical significance.