Time synchronization and real-time data acquisition method for multi-sensor combined navigation system

Abstract

The invention relates to a time synchronization and real-time data acquisition method for a multi-sensor combined navigation system, comprising the steps that time synchronization is realized on the basis of a linux local clock, and real-time modification of a standard linux system is carried out, so that the operating system running on the computing carrier meets the hard real-time requirement; data acquisition and time synchronization are realized, so that the time marks of the data acquired by all the sensors are kept consistent with the standard GPS, then entering a buffer area and fusingthe combined navigation data to prepare the combined navigation data can be carried out; the data acquisition is synchronous with the time, and the implementation mode is as follows: the PPS signal output by the GPS receiver serves as a reference, the local clock of the calculation carrier is corrected, and then the time scale is marked by utilizing the local clock of the calculation carrier as other sensors. Under the condition that additional hardware is not needed, time synchronization precision within 10 ms can be achieved, the requirements of multi-sensor data fusion can be met, and programming is simple, application range is wide, and transplant is convenient.

Description

technical field [0001] The invention belongs to the field of multi-sensor integrated navigation, in particular to a time synchronization and data collection method for real-time multi-sensor integrated navigation. Background technique [0002] In complex ground environments such as urban canyons, GNSS signals cannot provide high-precision and reliable positioning and navigation services due to their susceptibility to occlusion and multi-path effects. preferred option. The inconsistency of data time scales due to the difference in the sampling time of each sensor data will introduce errors to the data fusion of integrated navigation and even lead to fusion errors. Therefore, solving the time synchronization problem of multi-sensor data, especially under real-time conditions, is to The key to optimal fusion of multiple sensors. [0003] At present, the time synchronization of real-time multi-sensor data is divided into two schemes. One is to use an external FPGA chip as a un...

AI Technical Summary

Problems solved by technology

In order to make the time synchronization accuracy meet the requirements by using software synchronization, it is often necessary to make the operating system meet the hard real-time requirements. Existing research mostly uses Linux based on RTAI, Xenomai and other separate real-time kernels for time synchronization, but this method is often only for A specific chip type, and its programming is based on a separate real-time kernel, it is difficult to implement in practical applications, and the versatility is not good

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