Pseudo-satellite indoor positioning method based on UKF algorithm

Abstract

The invention discloses a pseudo-satellite indoor positioning method based on a UKF algorithm. The method comprises the steps that (1) a pseudo-satellite double-difference pseudo-range observation model is constructed; and (2) the UKF algorithm is used to carry out indoor positioning on a pseudo-satellite. According to the invention, the pseudo-satellite double-difference pseudo-range observationmodel is constructed to eliminate the influence of receiver clock difference, satellite clock error, thermosphere delay and troposphere delay in pseudo-satellite pseudo-range measurement values; for the problem of a large linearization error generated by an independent networking pseudo-satellite system which uses an EKF algorithm, the linearization error of the observation model is analyzed; theinfluencing factor of the linearization error is the error of the distance between the pseudo-satellite and a receiver and the position of the receiver; when the coordinate error of the receiver is larger and the distance between the satellite and the receiver is smaller, the linearization error is larger; in pseudo-satellite indoor positioning, the UKF algorithm is used for positioning to avoid the linearization error; and when the coordinate error of the receiver is relatively large, faster convergence speed and higher indoor positioning accuracy than the EKF algorithm can be acquired.

Description

technical field [0001] The invention relates to the technical field of pseudolite system positioning, in particular to a pseudolite indoor positioning method based on a UKF algorithm. Background technique [0002] The reliability and accuracy of satellite navigation systems depend on the geometric distribution of the number of visible satellites. But once you are indoors, the number of visible satellites will decrease, which will greatly affect the positioning accuracy. For the problem of low positioning accuracy caused by insufficient visible satellites, pseudolites can be used for positioning. Pseudo-satellites are also called ground-based satellites or ground-based satellites. Their functions and principles are similar to those of navigation satellites, and they have the characteristics of low cost and flexible configuration. Different from navigation satellites, pseudolites are deployed on the ground and can be set flexibly, so it can solve the problems of small number...

AI Technical Summary

Problems solved by technology

However, because the distance from the pseudolite to the user receiver is much closer than the distance from the navigation satellite to the user receiver, the linearization error of the pseudolite pseudorange observation equation caused by the EKF algorithm will be relatively large

And when the distance between the satellite and the user receiver is small, the error of the user receiver coordinates has a greater impact on the linearization error

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