Track fusion system time zero-crossing processing method

Abstract

The invention discloses a time zero-crossing processing method for a track fusion system, which is used for carrying out unified format processing on date information in the track fusion system and comprises the following steps of: firstly, adding system date information to received original track time; the current date and time of the track fusion system and the original track date and time are converted into internal time information with millisecond as the unit, and judgment and time restoration are carried out when the time crosses the zero point. According to the track fusion system time zero-crossing processing method provided by the invention, the problem of time zero crossing can be solved under the condition that other systems are not influenced, the repair time and engineering difficulty of the problem are effectively reduced, the processing of the time zero-crossing condition in the air-situation fusion process is realized, and the processing efficiency is improved. According to the method, the main function is to provide a new solution idea and method for the zero crossing problem of the track fusion system, and the reusability is high.

Description

Technical Field

[0001] The invention belongs to the technical field of multi-source data fusion, and relates to a method for processing a time crossing zero point of a track fusion system of a multi-source radar system, and more specifically, to a method for processing a time crossing zero point of a track fusion system. Background Art

[0002] In a multi-source radar system, in order to obtain comprehensive and accurate target track information and improve the system's information acquisition capabilities, it is necessary to comprehensively process the local track information provided by multiple sensors to form a complete, consistent and accurate description of the input track information received by the system, namely track fusion. The track fusion system receives track information sent by each air situation source, namely the original track, which contains the temporal and spatial information of the track. In the wireless communication mode, in order to save the bandwidth occupancy of track information transmission, the time information in the track information is usually compressed, and the relative time method is used. For example, the 00:00:00 (hour: minute: second) time of the day is used as the start time and converted into milliseconds relative to the start time. When the time changes from 23:59:59 to 00:00:00, since the track fusion system time usage logic only considers the increase of hour, minute, second and millisecond information, and does not consider the increase of date information, the hour, minute, second and millisecond fallback after crossing zero o'clock is not handled correctly. After the track fusion system time is changed to 00:00:00, the track fusion system mistakenly judges it as an update abnormality, which leads to track fusion abnormality.

[0003] Since the track information transmission protocol is widely used, the solution of adding date information to the track information transmission protocol will increase the track information transmission bandwidth, which will put pressure on the information transmission of the multi-source radar system. At the same time, the number of systems involved will be large, resulting in a long time to repair the time crossing zero point problem and high engineering difficulty. Therefore, to solve the time crossing zero point problem, it is necessary to modify and improve the track fusion system without affecting other systems. Based on this multi-source radar system track fusion system time crossing zero point processing method, it can provide an effective method for solving the time crossing zero point for the other systems with strong time correlation under the multi-source sensor system, which helps to improve work efficiency and improve the system robustness and robustness. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] The present invention aims at the technical problem of abnormal fusion of time crossing zero point in a track fusion system, and provides a method for processing time crossing zero point in a track fusion system, which effectively solves the problem of track fusion failure caused by crossing zero point and improves the stability of the system.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the present invention provides a method for processing time zero crossing of a track fusion system, which comprises the following steps:

[0008] Step 1: The track fusion system receives the original track and adds the date to the original track time information. The date uses the current date information of the track fusion system.

[0009] Step 2: Convert the time with date to time information in milliseconds. Using January 1, 1970 0:0:0:0:0 milliseconds as the starting time, convert the current system date and the input track time information into the internal time information format and subtract the time difference from the starting time to get the time difference in milliseconds. The data type is long long (8 bytes).

[0010] Step 3: Take the original track with date and fusion system time information as input, and verify the validity of the input year, month, hour, minute, second, and millisecond.

[0011] Step 4: Determine whether the current year is a leap year based on the year. Set the number of days per month based on the month: January, March, May, July, August, October, and December have 31 days, April, June, September, and November have 30 days, and February has 28 days or 29 days (leap year). Check the legality of the input day.

[0012] Step 5: Calculate the total number of milliseconds from 1970 to the input year, calculate the total number of milliseconds from January to the input month, and calculate the total number of milliseconds from the 1st to the input day. Calculate the total number of milliseconds from 0 o'clock to the input hour, minute, second, and millisecond. Add the above total milliseconds to get the total number of milliseconds corresponding to the date + time.

[0013] Step 6: Due to communication delays in the transmission of the original track, or deviations between the original track time reference and the track fusion system, after the original track is added with date information, date anomalies may occur when the time crosses zero. The original track time information is correctly restored.

[0014] Step 7: Let d be the time difference threshold between the time information t0 of the track fusion system in milliseconds and the time information t1 of the original track in milliseconds, as the basis for judging whether it is within the time zero point range. Usually, the value range of d is based on the maximum communication delay and the maximum deviation between the original track time reference and the track fusion system time reference. When |t0-t1|<d, it is not within the zero point range, and t1, that is, the time information of the original track, is output.

[0015] Step 8: When |t0-t1|>d, it is in the zero-crossing range and needs to be processed in two cases. When t0<t1, that is, the time information of the track fusion system is less than the time information of the original track, the date of the original track should be the previous day, and the time information of the original track is t1=t1-24*60*60*100. When t0>t1, that is, the time information of the track fusion system is greater than the time information of the original track, the date of the original track should be the next day, and the time information of the original track is t1=t1+24*60*60*1000. Output t1, which is the time information of the original track.

[0016] (III) Beneficial effects

[0017] 1) The present invention provides a solution to the cross-time zero point problem of the track fusion system without affecting other systems, effectively reducing the repair time and engineering difficulty of the problem;

[0018] 2) Aiming at the communication delay and system time difference problem in the track fusion system, the present invention provides a solution for judging the situation when the track time and the system time cross the zero point during the track crossing zero point process, effectively solving the problem of time crossing the zero point caused by communication delay and system time difference, and improving the system stability;

[0019] 3) The present invention designs a time processing flow under a multi-source radar system. Based on this time processing flow, the software failure problem caused by the time crossing zero point problem and the software time information crossing the boundary problem after January 19, 2038 can be effectively solved, effectively improving the system life;

[0020] 4) The present invention unifies the track time format and increases the time content information, effectively reducing the complexity of time conversion caused by different time formats and improving the system functionality problems caused by the small amount of time content information. The overall process is highly reusable, reducing the problem of repeated development caused by time problems and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flow chart of a time zero-crossing processing method for a track fusion system of the present invention;

[0022] Figure 2 This is a flow chart of the cross-time zero-point date restoration process of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0024] like Figure 1 , Figure 2As shown, a time-crossing zero point processing method for a track fusion system comprises the following steps:

[0025] Step 1: The track fusion system adds date information to the received original track time. Since the original track has no date information, only relative time information, it can be converted into hours, minutes, seconds, and milliseconds. During the processing, the track fusion system adds the date to the original track time information, and the date uses the current date information of the track fusion system.

[0026] Step 2: In order to facilitate track fusion, it is necessary to convert the time information with date into time information in milliseconds. Since the track fusion system software is implemented in C language, there is a time_t mktime (struct tm*timeptr) function in the C language standard library that can convert the date parameter timeptr into a time_t type timestamp. The return value of this function is of type time_t. In a 32-bit system, the time_t type is 4 bytes. It will overflow after January 19, 2038, and the correct timestamp cannot be obtained. At the same time, the timestamp converted by this function is accurate to the second level. The track fusion system requires the original track time information to be accurate to the millisecond level, so this function cannot meet the time conversion requirements of the track fusion system. In order to make track fusion cross-hardware platform or operating system, the start time is 0:0:0:0:0:0 millisecond on January 1, 1970, and the current date + time is converted into the time difference with the start time, in milliseconds, of type long long (8 bytes).

[0027] Step 3: Take the original track with date and the fusion system time information as input, and perform a validity check on the input year, month, hour, minute, second, and millisecond. If the year, month, hour, minute, second, and millisecond are illegal, an error code is returned. Among them, 1970≤year≤3136, 1≤month≤12, 0≤hour≤23, 0≤minute≤59, 0≤second≤59, 0≤millisecond≤999.

[0028] Step 4: Determine whether the current year is a leap year (divisible by 4 and not divisible by 100, or divisible by 400) based on the year. Set the number of days per month based on the month: January, March, May, July, August, October, and December have 31 days, April, June, September, and November have 30 days, and February has 28 days or 29 days (leap year). Check the legality of the input day. If the day is illegal, return an error code.

[0029] Step 5: Calculate the total number of milliseconds from 1970 to the input year. For each year, if it is a leap year (366 days): add 366×24×60×60×1000 milliseconds. If it is a common year (365 days): add 365×24×60×60×1000 milliseconds. Calculate the total number of milliseconds from January to the input month, and calculate the total number of milliseconds from the 1st to the input day. Calculate the total number of milliseconds from 0 o'clock to the input hour, minute, second, and millisecond. Add the above total number of milliseconds to get the total number of milliseconds corresponding to the date + time.

[0030] Step 6: When the original track time reference (detection source time reference) is consistent with the time reference of the track fusion system, due to the communication delay in the transmission of the original track information, the time received by the track fusion system is later than the original track time, or there is a deviation between the original track time reference and the track fusion system. When the track fusion system adds date information after receiving the original track, date anomalies may occur when the time crosses zero, and the original track time information needs to be correctly restored.

[0031] Step 7: After receiving the original track, the track fusion system processes the time information. The original track time information is expressed as h1:m1:s1:ms1. Among them, h1:m1:s1:ms1 are the hours: minutes: seconds: milliseconds of the original track. Get the current date and time of the track fusion system, expressed as Y0-M0-D0 h0:m0:s0:ms0. Among them, Y0-M0-D0 h0:m0:s0:ms0 are the current year-month-day hours: minutes: seconds: milliseconds of the track fusion system. Convert the current date and time of the track fusion system into time information t0 in milliseconds.

[0032] Step 8: Assume that the original track date is the current date of the track fusion system, that is, the date and time of the original track is Y0-M0-D0 h1:m1:s1:ms1. Convert the date and time of the original track into time information t1 in milliseconds.

[0033] Step 9: Let d be the time difference threshold between the track fusion system time information t0 and the original track time information t1, as the basis for judging whether it is within the time span zero point range. Usually, the value range of d is based on the maximum communication delay and the maximum deviation between the original track time reference and the track fusion system time reference. When |t0-t1|<d, it is not within the span zero point range, and t1, i.e., the time information of the original track, is output.

[0034] Step 10: When |t0-t1|>d, it is in the zero-crossing range and needs to be processed in two cases. When t0<t1, that is, the time information of the track fusion system is less than the time information of the original track, the date of the original track should be the previous day, and the time information of the original track is t1=t1-24×60×60×1000. When t0>t1, that is, the time information of the track fusion system is greater than the time information of the original track, the date of the original track should be the next day, and the time information of the original track is t1=t1+24×60×60×1000. Output t1, which is the time information of the original track.

[0035] By converting and parsing the internal time format, the data synchronization problem caused by time crossing zero and communication delay in the fusion process can be solved, which can effectively improve the stability and reliability of the system.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for processing time zero point in a track fusion system, characterized by: The method comprises the following steps: Step 1: The track fusion system receives the original track and adds the date to the original track time information. The date uses the current date information of the track fusion system. Step 2: Convert the time with date into internal time information, taking January 1, 1970 0:0:0:0:0 milliseconds as the starting time, convert the current system date and the input track time information into the internal time information format and subtract the time difference from the starting time to get the time difference, in milliseconds, and the data type is long long (8 bytes); Step 3: Take the original track with date and the fusion system time information as input, and check the legitimacy of the input year, month, hour, minute, second, and millisecond; Step 4: Determine whether the current year is a leap year based on the year, and set the number of days in each month based on the month: January, March, May, July, August, October, and December are 31 days, April, June, September, and November are 30 days, and February is 28 days or 29 days (leap year). Check the legality of the input day; Step 5: Calculate the total number of milliseconds from 1970 to the input year, calculate the total number of milliseconds from January to the input month, calculate the total number of milliseconds from the 1st to the input day; calculate the total number of milliseconds from 0 o'clock to the input hour, minute, second, and millisecond, and add the above total number of milliseconds to get the total number of milliseconds corresponding to the date + time; Step 6: Due to the communication delay in the transmission of the original track, or the deviation between the original track time reference and the track fusion system, after the original track is added with date information, date anomalies may occur when the time crosses zero. The original track time information is correctly restored; Step 7: Let d be the time difference threshold between the time information t0 of the track fusion system in milliseconds and the time information t1 of the original track in milliseconds, as the basis for judging whether it is in the time crossing zero point range; usually the value range of d is based on the maximum communication delay and the maximum value of the deviation between the original track time reference and the track fusion system time reference; when |t0-t1|<d, it is not in the zero crossing range, then output t1, that is, the time information of the original track in milliseconds; Step 8: When |t0-t1|>d, it is in the zero-crossing range and needs to be processed in two cases; when t0<t1, that is, the time information of the track fusion system is less than the time information of the original track, the date of the original track should be the previous day, and the time information of the original track is t1=t1-24*60*60*1000; when t0>t1, that is, the time information of the track fusion system is greater than the time information of the original track, the date of the original track should be the next day, and the time information of the original track is t1=t1+24*60*60*1000; output t1, that is, the time information of the original track.

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