IRIG-B AC code analysis precision improvement method and device

Abstract

The application discloses an IRIG-B alternating code analysis precision improving method and device, the method comprises the following steps: solving the interval standard value between adjacent pulses and the position offset value of the latest pulse based on a first relationship and a second relationship; obtaining the accurate pulse position of the next pulse based on the actual value of the pulse position of the latest pulse, the position offset value of the latest pulse and the interval standard value. The second relationship is that, in the case that the number of pulses in the B code second pulse sequence is large enough, the position offset value distribution of all pulses in the second pulse sequence conforms to normal distribution. The application effectively eliminates the error existing in the IRIG-B alternating code analysis, and improves the analysis precision and stability of the IRIG-B alternating code.

Description

Technical Field

[0001] This invention relates to the field of signal transmission technology, specifically to a method and apparatus for improving the parsing accuracy of IRIG-B AC codes. Background Technology

[0002] IRIG-B code is a commonly used serial transmission method in time systems. Compared to parallel transmission, IRIG-B serial transmission has simpler physical connections, longer transmission distances, and standardized interfaces. IRIG-B code includes two types: B(DC) code and B(AC) code. B(AC) code has a longer transmission distance than B(DC) code, but there is a certain loss in transmission accuracy.

[0003] The conventional B(AC) code decoding method involves low-pass filtering the analog signal, performing AD sampling to convert the analog signal to a digital signal, performing digital filtering and demodulation, and finally directly decoding. This method suffers from low resolution accuracy when the AD sampling frequency is limited, and the resolved second pulse is unstable and subject to offset.

[0004] Existing B(AC) code parsing methods require analog-to-digital (ADC) sampling of the analog data. However, the sampling frequency and accuracy are limited. Furthermore, errors in the external environment and the ADC's own data conversion introduce errors during sampling, leading to inaccurate results. Figure 1 As shown.

[0005] Because ADCs have sampling errors, and B(AC) demodulation converts analog waveforms into digital waveforms through threshold determination, the demodulated B(DC) boundary drifts, such as... Figure 2 As shown. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method and apparatus for improving the parsing accuracy of IRIG-B AC codes, effectively eliminating errors in B(AC) parsing and improving the parsing accuracy and stability of B(AC) codes. The technical solution is as follows: Firstly, a method for improving the parsing accuracy of IRIG-B communication codes is provided, including the following steps: Obtain the decoded B-code second pulse sequence; The standard value of the interval between adjacent pulses and the position offset value of the latest pulse are solved based on the first and second relations. The position offset value represents the offset between the actual position and the theoretical position of the pulse. The first relation is: for any two pulses A and B in the B-code second pulse sequence, the cumulative deviation generated by all pulses in the segment AB of the pulse sequence is the difference between the position offset of pulse A and the position offset of pulse B. The second relation is: when the number of pulses in the B-code second pulse sequence is large enough, the distribution of the position offset values ​​of all pulses in the second pulse sequence conforms to a normal distribution. The pulse position of the latest pulse is corrected based on the pulse position offset value of the latest pulse; The accurate pulse position of the next pulse is obtained by adding the aforementioned interval standard value to the pulse position of the latest pulse.

[0007] Specifically, this application derives a relational expression containing the position offset value of each pulse based on the first relational expression. Further combining this with the second relational expression, it can be seen that, under the condition of a normal distribution, the expected value of the position offset value of all pulses is 0. Therefore, it can be understood that when the number of pulses in the B-code second pulse sequence is sufficiently large, the expected value of the position offset of all pulses between the first and last pulses is 0. Consequently, the position offset values ​​of the first and last pulses are consistent. Furthermore, it can be concluded that when the number of pulses in the B-code second pulse sequence is sufficiently large, the actual total distance between the first and last pulses is consistent with the theoretical total length. That is, if the standard interval between adjacent pulses is denoted as... The total actual distance between the first pulse and the last pulse is . The product of the number of adjacent pulse intervals.

[0008] In one implementation, based on the theory of the first and second relations described above, the calculation of the standard value of the interval is discussed. One simple method is as follows: the standard value of the interval Methods for obtaining [the information] include: The standard value of the interval is obtained based on the second relation. : ,in, This represents the actual distance between the first pulse and the (M+1)th pulse, where M is the number of pulses that satisfy the second relation.

[0009] In one implementation, the interval standard value Methods for obtaining [the information] include: (1) Based on the first relation, the third relation is obtained, which represents the actual distance between any two pulses, i.e. ,in , For the first The position offset of each pulse For the first The position offset of each pulse For the first and the The cumulative deviation generated by all pulses between them ; (2) When the value of M is large enough, a preset analysis is performed on each pulse from the (M+1)th pulse to the (M+N)th pulse. The preset analysis process includes: Get the current pulse Obtain the interval distance from the previous M pulses to the current pulse respectively. , … , The values ​​range from M+1 to M+N; Current pulse The fourth relation is derived by accumulating the intervals between the previous M pulses and the current pulse: ; (3) To By accumulating the results, we obtain the fifth relation: ; (4) Obtain the standard value of the interval based on the fifth relation. .

[0010] Regarding the standard value of the calculation interval In addition to the above method, this application provides another consideration. It can be understood that, as described in the third relation above, the actual distance between any two pulses is composed of the sum of the theoretical distances of all pulses between the two pulses and the cumulative offset of all pulses between the two pulses. That is, the actual distance between any two pulses is based on the position offset of the leftmost pulse, the position offset of the rightmost pulse, and the standard value of the interval between adjacent pulses. Based on the second relation above, it can be determined that when the number of pulses in the B-code second pulse sequence is sufficiently large, the cumulative position offsets of all pulses are 0. Therefore, the third relation above is modified to form the fourth relation above. For the "actual distance length between any two pulses," several suitable combinations of "any two pulses" are selected. In this embodiment, the right pulse in the "any two pulses" is fixed, thus fixing the position offset of the right pulse in the "actual distance length between any two pulses." The left pulse in the "any two pulses" is set sequentially to each pulse in the B-code second pulse sequence that satisfies the second relation. Based on this, the position offset of the left pulse in the "actual distance length between any two pulses" is eliminated using normal distribution characteristics, thus obtaining the fourth relation above. That is, for the first M pulses to the current pulse... Cumulative intervals between Based on the standard value of adjacent pulse interval and current pulse The position offset is determined, and the current pulse is further analyzed. The positions are changed so that N different "current pulses" are accumulated. The positional offset of "" conforms to the normal distribution of the second relationship mentioned above, so as to achieve the following: "Current Pulse" The "position offset" is eliminated. Based on this, the fourth relation above is modified in this application to form the fifth relation above, which is used for the current pulse. The position is shifted one position to the right in sequence, and the fourth relational expression corresponding to each current pulse is obtained in sequence. For all different current pulses... The fourth relation is accumulated to achieve the summation of each fourth relation. "Current Pulse" By eliminating the "position offset," we can obtain the different "actual distance length between any two pulses" as shown in the fifth relation above. ( The values ​​range from M+1 to M+N; Value =1, 2, ..., -1) accumulation Standard value of interval between adjacent pulses It is related to the pulse position offset value, but not to the pulse position offset value.

[0011] Furthermore, based on this fifth relation, the standard value of the interval between adjacent pulses can be determined. ; Furthermore, based on the standard value of adjacent pulse interval Substituting into the fourth relation above, we can obtain a definite position offset value for the current pulse.

[0012] In one implementation, the pulse position offset value of the latest pulse Determined based on the fourth relation. satisfy: .

[0013] Considering the need for accurate position prediction of the next pulse that has not yet occurred in this application, the embodiments of this application utilize the aforementioned fourth relation to obtain the position offset value of the latest pulse, i.e., the Nth pulse. Further, based on the actual position of the latest pulse, the position offset value of the latest pulse, and the standard value of the interval between adjacent pulses... Obtain the accurate pulse position of the next pulse.

[0014] In one implementation, correcting the pulse position of the latest pulse based on the pulse position offset value of the latest pulse includes: The pulse position correction value of the Nth pulse = the actual pulse position value of the Nth pulse - .

[0015] In one implementation, the step of adding the interval standard value to the pulse position of the latest pulse to obtain the accurate pulse position of the next pulse includes: The accurate pulse position of the (N+1)th pulse = the pulse position correction value of the Nth pulse + .

[0016] In this application, when accurately predicting the position of the next pulse, the pulse position of the latest pulse is first corrected, and then based on the standard value of the interval between adjacent pulses... Obtain the accurate pulse position of the next pulse. This accurate pulse position is a prediction of the next second pulse based on the currently resolved second pulse position, providing a second pulse with high time accuracy at the predicted position.

[0017] In one implementation, the case where the number of pulses in the B-code second pulse sequence in the second relation is sufficiently large includes: the position offset of the Mth pulse in the B-code second pulse sequence is the same as the position offset of the 1st pulse. It can be understood that in this embodiment, the case where the number of pulses in the B-code second pulse sequence in the second relation is sufficiently large can be determined based on empirical values. That is, in a fuzzy sense, the number of pulses is large enough to ensure that the position offset values ​​of all pulses in the B-code second pulse sequence conform to a normal distribution. Alternatively, the number of pulses satisfying the second relation can be determined by determining that the position offset values ​​of the M pulses from the 1st to the Mth pulses conform to a normal distribution when the position offset of the Mth pulse is the same as the position offset of the 1st pulse.

[0018] In one implementation, the actual spacing between the two pulses Obtained based on local clock counting; further, the method for improving the accuracy of AC code parsing also includes: Based on the accurate pulse position of the (N+1)th pulse and Perform error feedback and calibration on the local clock.

[0019] Specifically, based on the accurate pulse position of the (N+1)th pulse and the standard value of the interval between adjacent pulses... It can align the second time of the local clock system with the B code, and for clock systems with higher precision requirements, it can also achieve the uniformity of millisecond pulses and microsecond pulses.

[0020] In one implementation, before acquiring the decoded B-code second pulse sequence, the following steps are included: Perform linear interpolation on the digital signal sampled by the ADC; The linearly interpolated digital signal is filtered, demodulated, and decoded to obtain whole-second pulses and time information.

[0021] Secondly, an IRIG-B AC code parsing accuracy enhancement device is provided, comprising: The B-code pulse sequence acquisition unit is used to acquire the decoded B-code second pulse sequence. The first accurate value acquisition unit is used to solve the standard value of the interval between adjacent pulses and the position offset value of the latest pulse based on the first relation and the second relation. The position offset value represents the offset between the actual position and the theoretical position of the pulse. The first relation is: for any two pulses A and B in the B-code second pulse sequence, the cumulative deviation generated by all pulses in the segment AB is the difference between the position offset of pulse A and the position offset of pulse B. The second relation is: when the number of pulses in the B-code second pulse sequence is large enough, the distribution of the position offset values ​​of all pulses in the second pulse sequence conforms to a normal distribution. The second accurate value acquisition unit is used to correct the pulse position of the latest pulse based on the pulse position offset value of the latest pulse; The third accurate value acquisition unit adds the aforementioned interval standard value to the pulse position of the latest pulse to obtain the accurate pulse position of the next pulse.

[0022] The method for improving the parsing accuracy of IRIG-B communication codes according to the present invention has the following beneficial effects: 1. Based on the traditional analytical method, pulse counting statistics are added. Utilizing the characteristic that pulse position offset values ​​conform to a normal distribution, a standard value for the interval between adjacent pulses is established. The position offset value of the latest pulse is analyzed to reduce random errors and improve the analysis accuracy.

[0023] 2. By adopting a predictive approach, the precise position of the next second pulse is predicted based on the current second pulse position and statistical calculation values, and a new second pulse signal is generated, thereby improving the accuracy and stability of the resolved whole-second moments.

[0024] 3. Based on traditional methods, the data sampling rate is indirectly increased through interpolation, thereby reducing the time jitter of the parsing results.

[0025] 4. A feedback mechanism is introduced to use the calculated ideal second pulse interval and precise second pulse position as a reference for the local clock system, ensuring the accuracy and stability of the local clock system. Attached Figure Description

[0026] Figure 1 This is a diagram illustrating the inaccuracy of sampling results when existing B(AC) code parsing methods perform AD sampling on analog data. Figure 2 This is an application diagram illustrating the drift of the demodulated B(DC) boundary in existing technologies.

[0027] Figure 3 This is a schematic diagram of B(AC) signal upsampling in an IRIG-B AC code parsing accuracy improvement method according to an embodiment of this application; Figure 4 This is a schematic diagram illustrating the principle of second pulse interval statistics in an IRIG-B AC code parsing accuracy improvement method according to an embodiment of this application; Figure 5 This is a flowchart illustrating one method for improving the parsing accuracy of IRIG-B communication codes. Figure 6 This is a flowchart illustrating another implementation method for improving the parsing accuracy of the IRIG-B communication code. Detailed Implementation

[0028] The specific implementation methods of this application will be described below. Example

[0029] See Figure 5 This application provides a method for improving the parsing accuracy of IRIG-B communication codes, which includes the following steps: Step 1: Perform linear interpolation on the digital signal sampled by the ADC, such as... Figure 3 As shown; Step 2: Filter, demodulate, and decode the linearly interpolated digital signal to obtain whole-second pulses and time information; Step 3: Obtain the decoded B-code second pulse sequence; Step 4: Count the second pulse interval using the local clock to obtain the current pulse. From the previous M pulses to the current pulse actual distance ,in Indicates the first Each pulse position; Step 5, based on the fourth relation, i.e., the current pulse Cumulative value of the interval between the previous M pulses and the current pulse And the fifth relation, i.e., the current pulse ( The cumulative value of the interval between the previous M pulses (ranging from M+1 to M+N) and the current pulse. Solve for the standard value of the interval between adjacent pulses. The position offset value of the latest pulse (the Nth pulse) ,in, For the first The position offset of each pulse, the position offset value characterizes the offset between the actual position and the theoretical position of the pulse (see...). Figure 4 ); Step 6: Correct the position of the latest pulse (the Nth pulse) and accurately predict the position of the next pulse: Pulse position correction value of the Nth pulse = Actual pulse position value of the Nth pulse - The accurate pulse position of the (N+1)th pulse = the pulse position correction value of the Nth pulse + ; Step 7: Based on the accurate pulse position of the next pulse (the N+1th pulse), perform error feedback and calibration on the local clock. In addition, if the local clock has accuracy requirements, millisecond pulse and microsecond pulse uniformization can also be performed on the local clock.

[0030] Calculate the millisecond pulse interval: A uniform millisecond pulse is given according to the interval.

[0031] Calculate the microsecond pulse interval: It also provides uniform microsecond pulses according to the interval. Example

[0032] See Figure 6 This application provides an IRIG-B AC code parsing accuracy improvement method, which offers another implementation for step 5 in embodiment 1 above, namely, obtaining the standard value of adjacent pulse intervals. The method for determining the position offset value of the latest pulse (the Nth pulse) includes the following steps: (1) Based on the sixth relation Obtain the standard value of the interval ,in, This represents the actual distance between the first pulse and the (M+1)th pulse, where M is the number of pulses that satisfy the second relation. (2) The standard interval values ​​obtained in (1) above Substituting into the fourth relation above Take in the fourth relation Let the latest pulse be the Mth pulse in this embodiment. That is, if we perform accurate pulse position prediction on the (M+1)th pulse, then step (2) can obtain the position offset of the latest pulse (the Mth pulse). .

[0033] The remaining steps in this embodiment are the same as in Embodiment 1 above, and will not be repeated here.

[0034] The present invention provides a method for improving the parsing accuracy of IRIG-B AC codes. Based on the conventional B AC code parsing method, it adds statistical analysis of the time distribution of the parsing results, calculates the offset value between the parsing results and the actual second time, as well as the standard integer second interval, further eliminates parsing errors, and provides accurate integer second pulses, thereby improving the accuracy and stability of B(AC) parsing of integer second time.

[0035] This invention is not limited to the specific embodiments described above. Any modifications made by those skilled in the art based on the above concept without creative effort are within the scope of protection of this invention.

Claims

1. A method for improving the parsing accuracy of IRIG-B AC codes, characterized in that, Includes the following steps: Obtain the decoded B-code second pulse sequence; The standard value of the interval between adjacent pulses and the position offset value of the latest pulse are solved based on the first and second relations. The position offset value represents the offset between the actual position and the theoretical position of the pulse. The first relation is: for any two pulses A and B in the B-code second pulse sequence, the cumulative deviation generated by all pulses in the segment AB of the pulse sequence is the difference between the position offset of pulse A and the position offset of pulse B. The second relation is: when the number of pulses in the B-code second pulse sequence is large enough, the distribution of the position offset values ​​of all pulses in the second pulse sequence conforms to a normal distribution. The pulse position of the latest pulse is corrected based on the pulse position offset value of the latest pulse; The accurate pulse position of the next pulse is obtained by adding the aforementioned interval standard value to the pulse position of the latest pulse.

2. The method for improving the parsing accuracy of IRIG-B AC codes according to claim 1, characterized in that, The interval standard value Methods for obtaining [the information] include: The standard value of the interval is obtained based on the second relation. : ,in, This represents the actual distance between the first pulse and the (M+1)th pulse, where M is the number of pulses that satisfy the second relation.

3. The method for improving the parsing accuracy of IRIG-B communication codes according to claim 2, characterized in that, Interval Standard Value Methods for obtaining [the information] include: (1) Based on the first relation, the third relation is obtained, which represents the actual distance between any two pulses, i.e. ,in , For the first The position offset of each pulse For the first The position offset of each pulse For the first and the The cumulative deviation generated by all pulses between them ; (2) When the value of M is large enough, a preset analysis is performed on each pulse from the (M+1)th pulse to the (M+N)th pulse. The preset analysis process includes: Get the current pulse Obtain the interval distance from the previous M pulses to the current pulse respectively. , … , The values ​​range from M+1 to M+N; Current pulse The fourth relation is derived by accumulating the intervals between the previous M pulses and the current pulse: ; (3) To By accumulating the results, we obtain the fifth relation: ； (4) Obtain the standard value of the interval based on the fifth relation. .

4. The method for improving the parsing accuracy of IRIG-B communication codes according to claim 3, characterized in that, The pulse position offset value of the latest pulse Determined based on the fourth relation. satisfy: 。 5. The method for improving the parsing accuracy of IRIG-B AC codes according to claim 4, characterized in that, The correction of the pulse position of the latest pulse based on the pulse position offset value of the latest pulse includes: The pulse position correction value of the Nth pulse = the actual pulse position value of the Nth pulse - .

6. The method for improving the parsing accuracy of IRIG-B AC codes according to claim 5, characterized in that, The step of adding the interval standard value to the pulse position of the latest pulse to obtain the accurate pulse position of the next pulse includes: The accurate pulse position of the (N+1)th pulse = the pulse position correction value of the Nth pulse + .

7. The method for improving the parsing accuracy of IRIG-B AC codes according to claim 6, characterized in that, The cases in the second relation where the number of pulses in the B-code second pulse sequence is sufficiently large include: In the B-code second pulse sequence, the position offset of the Mth pulse is the same as the position offset of the 1st pulse.

8. The method for improving the parsing accuracy of IRIG-B AC codes according to claim 7, characterized in that, The actual spacing between the two pulses Obtained based on local clock counting; The method for improving the parsing accuracy of the communication code also includes: Based on the accurate pulse position of the (N+1)th pulse and Perform error feedback and calibration on the local clock.

9. The method for improving the parsing accuracy of IRIG-B AC codes according to claim 1, characterized in that, Before obtaining the decoded B-code second pulse sequence, the following steps are included: Perform linear interpolation on the digital signal sampled by the ADC; The linearly interpolated digital signal is filtered, demodulated, and decoded to obtain whole-second pulses and time information.

10. A device for improving the parsing accuracy of IRIG-B AC codes, comprising: The B-code pulse sequence acquisition unit is used to acquire the decoded B-code second pulse sequence. The first accurate value acquisition unit is used to solve the standard value of the interval between adjacent pulses and the position offset value of the latest pulse based on the first relation and the second relation. The position offset value represents the offset between the actual position and the theoretical position of the pulse. The first relation is: for any two pulses A and B in the B-code second pulse sequence, the cumulative deviation generated by all pulses in the segment AB is the difference between the position offset of pulse A and the position offset of pulse B. The second relation is: when the number of pulses in the B-code second pulse sequence is large enough, the distribution of the position offset values ​​of all pulses in the second pulse sequence conforms to a normal distribution. The second accurate value acquisition unit is used to correct the pulse position of the latest pulse based on the pulse position offset value of the latest pulse; The third accurate value acquisition unit adds the aforementioned interval standard value to the pulse position of the latest pulse to obtain the accurate pulse position of the next pulse.

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