A general timing method

Abstract

The invention relates to a general time service and time correction method, which belongs to the technical field of GPS / BD timekeeping. The method of the present invention first collects and processes the time information and second pulse information output by the GPS / BD module, and screens out the initial time; then performs time update according to the initial time and subsequent time information and second pulse information; in the GPS / BD module When the satellite is lost, the auxiliary clock can be used to keep local time on the basis of the previous time, and the time can be corrected after the GPS / BD module recaptures the ephemeris signal. This method is suitable for GPS / BD modules with an update frequency of 5Hz or above from different manufacturers. The time output accuracy reaches the microsecond level. Correcting and preventing time jumps ensures the accuracy and stability of punctual information.

Description

technical field [0001] The invention belongs to the technical field of GPS / BD time keeping, and in particular relates to a general time service and time correction method. Background technique [0002] At present, with the continuous iterative development of the airborne avionics system, the cross-linking relationship between various systems and equipment is becoming more and more complex. In order to grasp the status of each equipment during the flight, it is necessary to perform detailed post-event data analysis, which has great impact on the data. The time accuracy of the acquisition and recording equipment puts forward higher requirements. The timing and positioning signals sent by GPS / BD satellites are an optimal source of time information that can be shared by countless users. The GPS satellite signal wireless receiving module, that is, the GPS / BD module, is used to receive GPS / BD satellite timing information including second pulse signals, and can be used as a timing...

AI Technical Summary

Problems solved by technology

[0003] At present, there are mainly three methods of keeping time: 1. Use the GPS module positioning time as the initial value, and then use the local time keeping. This method may cause the initial positioning time to be inaccurate and cause the time to always deviate, or due to timekeeping errors time drift

2. Always use the time output by the GPS module as the local reference, but when the aircraft maneuvers in the air or crosses a valley, there will be a situation where there is no GPS time information due to star loss

3. When the GPS positioning information is valid, use the GPS module to output the information to keep the time, and when it is invalid, use the local time to keep the time, and then switch back to the GPS module to keep the time when it becomes valid again, but it cannot cope with the differences caused by GPS / BD modules of different manufacturers in harsh environments. Failure mode, such as time jump, inaccurate second pulse and other failures

[0004] To sum up, in the existing GPS / BD module timing method, after the GPS / BD signal is collected and processed, the time resolution output to the host module is millisecond level or lower, and the accuracy is low; directly using the analyzed GPS / BD module When the module loses satellites, it cannot guarantee to provide accurate time; it is also unable to deal with different failure modes of GPS / BD modules from different manufacturers in harsh environments, such as time jumps, inaccurate second pulses, etc.

Images