Research On Vehicle Positioning Technology Based On RFID

Continuous and accurate vehicle location information is the foundation of the Intelligent Transportation System(ITS).Traditional GPS positioning systems are vulnerable to signal loss in sheltered areas such as tunnels and bridges,causing vehicle positioning failure or lack of accuracy.A positioning system based on LANDMARC positioning algorithm in tunnels is proposed in this paper.The system realizes the continuous and accurate positioning of the vehicle in the tunnel by improving the layout of RFID tags that affect the positioning accuracy of the system and the LANDMARC positioning algorithm,thereby ensuring the effective functioning of ITS in urban traffic.Firstly,the triangular cellular mesh model is used to improve the reference label layout,which optimizes the size of the grid,reduces the number of labels and the interference,achieves the uniformity of the positioning of the label surrounding the label,and avoid the problem of inaccurate positioning of the vehicle due to inconsistent positioning of the positioning label of the positioning tag.Secondly,aiming at the problems of large amount of computation,low efficiency and poor adaptability when the traditional LANDMARC algorithm is applied for searching for adjacent tags,the traditional LANDMARC algorithm proposes the ergodicity of kinematical pre-judgment and the improved neighboring method to filter the tags before calculation,which greatly reduces the algorithm's The computational complexity and the probability of introducing bad tags increase system efficiency and adaptability.Kinematics pre-judgment traversal method and improved k-adjacent method are used to first filter and calculate the label,which greatly reduces the computational complexity of the algorithm and the probability of introducing bad labels,and improves system efficiency and adaptability.Virtual tags are used at the boundary to weaken the degradation of positioning accuracy at the boundaries of traditional algorithms.Finally,a new weight calculation method in the form of an index is applied when calculating the final position of the vehicle,which avoids the problem of algorithm disorder.At the same time,it more accurately reflects the location characteristics of the reference tag and improves the system positioning accuracy and stability.In order to verify the reliability and actual effect of the improved LANDMARC vehicle positioning method,static vehicle positioning and dynamic vehicle positioning tests at straight and curved roads were performed separately.The result shows that the LANDMARC vehicle positioning method proposed in this paper can be effective in achieving continuous,accurate and high-frequency vehicle positioning within the tunnel and can meet the requirements of ITS for vehicle position.