Detection And Mapping Of Radioactive Distribution Based On Mobile Robots

In recent years,with the rapid development of the nuclear industry,loss or loss of control of radioactive sources also occurs frequently.At present,people often use walking search to locate lost or out of control radioactive sources,this method is inefficient,and the health of the person is vulnerable to radiation damage.It is different to locate a radioactive source by detecting the relevant radioactive distribution in the area where the lost or uncontrolled radioactive source is likely to be located by a robot.This way not only improves work efficiency but also protects people from radiation damage.Therefore,according to the 13 th Five-Year Plan of National Nuclear Energy Development Project "Key Technologies Research of Nuclear Emergency Disposal Robot",this paper focuses on the task of radioactive distribution detection in radiation areas.A method of radioactivity distribution detection and radiation environment map construction of radiation field based on mobile robots is proposed.The research work of this paper will be carried out in the following sections:(1)In order to solve the problem of autonomous measurement based on robots in the process of radioactivity distribution detection,this paper creates the environmental map required for autonomous measurement by robot simultaneous localization and mapping(SLAM).In order to realize the autonomous navigation of mobile robots,this paper combines A* algorithm and DWA algorithm for hybrid path planning,mobile robot autonomous navigation is realized.Mobile robots use environmental maps and autonomous navigation to achieve autonomous measurements.(2)In order to solve the problem of locating radioactive sources through radioactivity distribution detection.In this paper,the mobile robot performs autonomous measurement and acquisition data along the specified path in the radiation area,and obtains the coordinate values and dose values of a small number of observation points in the area.For the small amount of data collected,a radiation source estimation algorithm based on Markov Chain Monte Carlo(MCMC)is proposed.Radioactive source information is obtained through an estimation algorithm in the area map.(3)In order to construct the radiation field in the 2D plane map,this paper describes the characteristics of the radiation field through the mathematical model,and proposes the construction algorithm of radiation field based on the contour line.The mobile robot finds points with equal radiation dose values in the region through observation and forms corresponding contour lines.Radioactive distribution of radiation field is described by radiation dose contour.(4)To verify the feasibility of the algorithm described in this paper,this paper builds a small mobile robot experimental platform,which realizes simultaneous localization and mapping and the autonomous measurement of the mobile robot.According to the sampling data,this paper uses MCMC algorithm to estimate the source information.Simultaneously,the construction of the radiation field is realized by simulation,and the experiment verifies the effectiveness of the contour method.