Tightly coupled INS/UWB integrated navigation system and method adopting fixed-interval CRTS smoothing

Abstract

The invention discloses a tightly coupled INS / UWB integrated navigation system and method adopting fixed-interval CRTS smoothing. The navigation system comprises an inertial navigation system (INS), a UWB radio tag, UWB wireless reference nodes, a reference system and a data processing system, wherein the inertial navigation system (INS) and the UWB radio tag are arranged on shoes of a pedestrian; the UWB wireless reference nodes and the reference system are arranged at a set position; the inertial navigation system (INS), the UWB radio tag and the reference system are connected with the data processing system respectively; the data processing system comprises a local data fusion filter, a Cubature Kalman Filter (CKF), a pseudo-distance data processing module, an RTS smoothing module and an average filtering module. The tightly coupled INS / UWB integrated navigation system and method has the benefits that the possibility of introducing truncation errors due to omitting of higher terms of Taylor expansion in a conventional tightly coupled integrated navigation model is effectively decreased.

Description

Technical field [0001] The invention relates to the technical field of combined positioning in a complex environment, in particular to an INS / UWB tight integrated navigation system and method that adopts CRTS smoothing in a fixed interval. Background technique [0002] In recent years, Pedestrian Navigation (PN), as an emerging field of navigation technology application, is receiving more and more attention from scholars from all over the world, and has gradually become a research hotspot in this field. However, in indoor environments such as tunnels, large warehouses, and underground parking lots, factors such as weak external radio signals and strong electromagnetic interference will greatly affect the accuracy, real-time and robustness of the target pedestrian navigation information acquisition. How to effectively integrate the limited information obtained in the indoor environment to eliminate the influence of the indoor complex environment and ensure the continuous stability...

AI Technical Summary

Problems solved by technology

For example, UWB devices are required to provide pedestrian navigation information, which requires that the environment where the target pedestrian is located must be able to obtain at least 3 reference node information, which greatly reduces the application range of the integrated navigation model. The sub-technology completes the positioning independently, but also introduces new errors, which is not conducive to the improvement of the accuracy of integrated navigation technology

In order to overcome this problem, scholars proposed to apply the tight combination model to the field of indoor pedestrian navigation. The tight combination model directly applies the original sensor data of the sub-techniques involved in the combined navigation to the final navigation information calculation, reducing the sub-techniques’ self-discipline. Solve the risk of introducing new errors and improve the accuracy of integrated navigation. However, it should be pointed out that the traditional compact integrated navigation models are all based on the first-order Taylor expansion, which inevitably introduces the truncation error of the system. , which seriously affects the accuracy of integrated navigation systems in the field of pedestrian navigation where low-cost sensors are commonly used

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