High-precision GNSS simulator time synchronization method

Abstract

The GNSS simulator is usually used in flight control system semi-physical simulation and can simulate navigation signals radiated by sky satellite constellations at the position of an airplane and assists the simulation system in completing flight control semi-physical simulation containing a satellite positioning receiver. The GNSS simulator and the simulation computer have different clock precisions so that the accumulated time difference of the GNSS simulator and the simulation computer in the long-time simulation process is continuously increased, and finally, the problem that the receivercannot be positioned due to time difference overrun within several hours occurs. The invention provides a high-precision GNSS simulator time synchronization method which has low cost and good effect,simulation computer hardware is not changed, instead, a set of external embedded timing equipment is adopted, the timing period in the equipment is continuously adjusted according to a pulse per second signal outputted by the GNSS simulator and the accumulated time can keep accurate tracking of the pulse per second, and the trigger signal is transmitted to the simulation computer according to thecorrected cycle beat, thereby thoroughly eliminating the accumulated time error between the simulation computer and the GNSS simulator.

Description

Technical field: [0001] The invention belongs to the field of flight control system simulation, and in particular relates to a high-precision GNSS simulator time synchronization method. Background technique: [0002] GPS / GLONASS / BD three-in-one (also known as GNSS) satellite signal simulator can simulate and generate military code and civil code of B3 frequency point of BD-2 system, and C / A code of frequency point L1 and L2 of GPS system constellation, GLONASS The satellite navigation signal of the system's full constellation L1 frequency point C / A code is used to replace the expensive and time-consuming on-site test, and it is not limited by the test in the actual application environment, simulating the navigation of the satellite constellation radiation in the sky where the aircraft is located Signals, assisting the real-time simulation computer system to complete the hardware-in-the-loop simulation of the aircraft control system containing the satellite positioning receiv...

AI Technical Summary

Problems solved by technology

In fact, the accuracy of the crystal oscillator is much lower than that of the rubidium atomic clock, which causes the cumulative time difference of this asynchronous system to continue to increase during the long-term operation, resulting in more and more deviations between the flight simulation trajectory and the internal recursive trajectory of the GNSS simulator. In the end, the receiver cannot be located due to the time difference exceeding the critical value within a few hours, and the test can only be terminated

[0006] After consulting with many parties, I learned that an aerospace institute that has a cooperative relationship with our company is also troubled by this problem. The imported Spirent GNSS simulator equipment used by it will also enter a fault state that cannot be located after a long period of simulation. Unable to achieve long-term closed-loop simulation test of GNSS simulator in the loop

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