Research On Vernier-based High-precision Positioning Technology Based On Differential Frequency Forwarding Beacons

China is the world’s largest manufacturer of hazardous chemicals and ranks first in the world in the production of some basic hazardous chemicals.In order to promote the digital transformation of safety management in hazardous chemical production,an inspection staff positioning system is indispensable.Existing indoor positioning systems often require wired connections and frequent and regular maintenance.However,due to the specific nature of the hazardous chemical production environment,open-wall wiring adds new safety hazards and it is difficult for hazardous chemical producers to stop work to carry out frequent maintenance on the positioning system.Therefore,this thesis proposes a low mains frequency,low power consumption and high accuracy indoor positioning technology with low power consumption,no wiring and low maintenance frequency,which can be well applied in hazardous chemical production environment.Further,the positioning system architecture was designed based on the positioning techniques proposed in this thesis and a proof-of-principle prototype was developed to verify the effectiveness of the positioning techniques proposed in this thesis.The main work includes:1、The indoor positioning technology and indoor positioning methods commonly used at present were analysed and compared,the advantages and disadvantages of several commonly used time interval measurement techniques were compared,and the vernier timing method and direct spread spectrum technology were analysed and simulated in detail respectively;for the special characteristics of the hazardous chemical production environment,the indoor positioning technology combining vernier timing method and direct spread spectrum technology was proposed,and the performance of this positioning technology was studied and analysed through simulation.The performance of this positioning technology was studied and analyzed through simulation.2、On the basis of the indoor positioning technology combining vernier timing method and direct spread spectrum technology,a vernier-type high-precision indoor positioning system architecture based on forwarding beacons is proposed with this positioning technology as the core,the forwarding scheme and frequency conversion scheme of this system are analysed and demonstrated in detail,the design of the scheme is carried out for the interrogator and forwarding beacons respectively,and the influence of the main frequency and spread spectrum code length on the signal-to-noise ratio is analysed theoretically,and the design of the spread spectrum parameters is carried out on the basis of the theoretical analysis.3、In order to verify the feasibility of the indoor positioning system architecture proposed in this thesis,a complete technical solution for the proof-of-principle prototype of cursor-based high-precision positioning technology based on differential frequency forwarding beacons is proposed,which includes the module design and hardware implementation of the interrogator and forwarding beacons,etc.A prototype system is developed and the effectiveness of the ranging and positioning functions of the indoor positioning technology proposed in this thesis is verified through experiments.