RFID (radio frequency identification) and UKF (unscented Kalman filter) based method for rapidly tracking indoor target

Abstract

The invention relates to an RFID and UKF based method for rapidly tracking an indoor target. A motion model is established according to the actual motion characteristics of the target, and an RFID measurement model is established according to the RFID measurement mechanism; a target motion characteristic is predicated according to the established motion model, and a target state predication value is obtained; a target state modification value is calculated by a UKF according to an original target measurement value and a target measurement predication value, then, the target state predication value is modified, and the target state estimation value is obtained; a target state covariance estimation value is calculated, and the error between the target state estimation value and a target state true value are measured; and meanwhile, a system self-adaption parameter is updated in real time according to the target state predication value, further, the motion model is updated, the process is repeated, and the target state predication value of the next time point is predicated according to the updated motion model, so that the indoor target is rapidly tracked, and the tracking accuracy is improved.

Description

technical field [0001] The invention relates to the technical field of target tracking, in particular to a method for realizing fast indoor target tracking based on RFID and UKF. Background technique [0002] RFID (Radio frequency identification) is the main component of indoor positioning and tracking systems. The RFID system consists of a radio frequency tag and a reader, and the radio frequency tag stores the identification information of the tag. When the target with the tag moves to the vicinity of the reader, the reader can obtain the identification information of the tag, thereby identifying a certain target, and at the same time obtain the distance information between the tag and the reader, and then can carry out the target locate or track. At present, the target positioning patents for RFID systems mainly include an indoor positioning method based on active RFID (201110101432), an intelligent storage system for steel products based on radio frequency identificati...

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Problems solved by technology

[0003] For moving targets, the above method has the following defects: 1. Because RFID can only obtain distance information with the reader, so in order to obtain accurate position data, it must rely on the distance information of a certain target obtained by multiple readers. The geometric relationship between the readers can get the position of the target, which increases the complexity of the system calculation; 2. The above methods all assume that the target is stationary, which does not conform to the actual situation of the moving target. The displacement of the moving target, Velocity and acceleration satisfy the basic constraint relationship of kinematics. Assuming that the target is stationary, the relationship is completely discarded, resulting in a reduction in the constraint relationship, which directly leads to inaccurate estimation of the trajectory of the moving target.

[0004] Obtaining real-time trajectories of targets is very commonly used in many tracking systems, such as pedestrian tracking in indoor venues, intelligent transportation and other fields. Therefore, the above invention is not suitable for RFID indoor target tracking systems that need to obtain real-time trajectories of moving targets

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