| At present,RFID,Zig Bee and other positioning technologies are used in the underground positioning system,which is timely and accurately known the distribution information of personnel and mobile equipment in the underground area,transmit it to the ground computer system,and help managers to dispatch and manage.However,there are some problems in these positioning technologies,such as the low accuracy of positioning,which belongs to the passive positioning technology architecture,and excessively relies on the underground power and communication system.Once the underground power supply is interrupted or the signal is unstable,the positioning system cannot work normally,and cannot meet the positioning requirements of emergency positioning and rescue in case of emergency.GPRM(Geomagnetic and Radio Positioning Method)is proposed for underground positioning with high precision and active positioning in the paper.The basic theory of GPRM,underground geomagnetic field spatial change,underground geomagnetic field adaptability evaluation and geomagnetic matching algorithm are studied.Firstly,GRPM positioning is based on geomagnetic matching,adding RFID tag positioning,and constructing a new positioning method.GRPM model includes tag identification and geomagnetic matching.According to the principle of active positioning,it is analyzed the hardware and software requirements of GRPM positioning system,designs the overall architecture of GRPM positioning prototype system,the main functions of the platform,and the sharing mechanism with the existing positioning methods in the paper.Secondly,the law of underground geomagnetic field change is studied.According to the structure of the underground tunnel,the ground road,building corridor,experimental mine tunnel,underground rescue tunnel and gold mine tunnel are selected as the test site,and the geomagnetic survey datum line and monitoring point are set up.ENVI-PRO proton magnetometer and FVM-400 fluxgate magnetometer are used,and carried out the geomagnetic map measurement,daily variation monitoring of geomagnetic,geomagnetic noise disturbance monitoring and other tests.After denoising and statistical analysis of the test data,the laws of spatial variation and time-domain disturbance of underground geomagnetic field are found.The underground geomagnetic field changes with the change of space.The measured geomagnetic value is not a constant.It will be disturbed with the time and the operation of the surrounding equipment,and the generated noise will be from tens to thousands of n T.Thirdly,the coefficient of variation and the ratio of rough variance are added to establish the matching characteristics of the underground geomagnetic map based on the matching characteristics of the geomagnetic map.It is found that the total magnetic field of roadway is only consistent with one or two adaptability evaluation results of XYZ magnetic component through the test of adaptability evaluation.Aiming at the problem of the uncertainty of the threshold of fitness evaluation,a multi factor combined fitness evaluation method based on multiple linear regression is optimized,which the overall accuracy of this method in the fitness evaluation test of samples is 90%,and the evaluation accuracy is high.At last,the MPMD(multi parameter matching model of least magnetic distance)algorithm of two-dimensional matching model is established by using the mathematical measurement method of Euclidean distance and vector inner product.The performance of MPMD algorithm is tested from the aspects of matching accuracy,matching speed and robustness.The test results show that the MPMD matching probability is still over 90% in the case of high noise magnetic disturbance of 200 nt,400nt and 600 nt,and the matching robustness is strong,which can meet the requirements of underground positioning.The GRPM positioning method is an active technical framework,which has independent positioning and good stability,and can be used as a supplement to the emergency positioning of the existing underground positioning system.The law of variation and disturbance of underground geomagnetic field and the two-dimensional MPMD matching model in the paper provide a theoretical basis for the application of underground GRPM positioning,which is of great significance to the development of underground intelligent rescue.Figure 73;Table 55;Reference 153... |
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