Reliable insurance release control method based on CPLD (Complex Programmable Logic Device)

Abstract

The invention discloses a reliable insurance releasing control method based on a CPLD (Complex Programmable Logic Device), which comprises the following steps: after the CPLD is powered on and reset, defining a multi-bit shift register and assigning an initial value; in the overload identification time window, carrying out sliding window value taking on the overload signal in the overload identification time window by using a shift register; before the shift register is completely replaced, the overload duration is calculated through a sampling value; after the shifting register is completely replaced, the overload duration is calculated through the shifting register; and the overload duration is judged, the overload is considered to be effective after the judgment condition is met, and at the moment, if the first-stage insurance release feedback input port is in an insurance release state, a second-stage insurance release signal is output. The method has the advantages of high recognition speed and high reliability, can be popularized and applied to various scenes in which the CPLD reliably recognizes external signals, and improves the anti-interference capability of products.

Description

Technical Field

[0001] The invention belongs to the technical field of in-line fuze electronic safety and arming device, and in particular relates to a reliable arming control method based on CPLD. Background Art

[0002] With the development of the information age, the core electronic safety and safety release device technology of in-line fuzes has gradually become one of the current research hotspots due to their advantages such as high safety and detectability. According to the requirements of GJB 373B-2019 "Fuze Safety Design Guidelines", the excitation of each independent safety device to release the safety should come from different environments or a combination of different environments. Therefore, electronic safety and safety release devices usually use different environmental excitation signals to control the release of each level of safety. For example, the second-level safety can be released by identifying ballistic overload.

[0003] In the process of ballistic overload identification, the overload within a period of time during the missile launch process is usually selected for identification. The existing identification algorithm mainly calculates the overload within the entire time window or divides the entire time window into segments and then calculates each segment in turn. When the calculation result meets the release condition, the insurance is released. If the former solution is selected, the identification time will be prolonged, while the latter will limit the judgment criteria and reduce reliability. It can be seen that any of the above methods cannot achieve a balance between real-time and reliability.

[0004] At the same time, the electronic components of the fuze need to gradually achieve autonomous control.

[0005] Therefore, it is particularly important to improve the accuracy of overload identification while ensuring real-time performance and to achieve reliable release of the fuze electronic insurance. Summary of the invention

[0006] The invention provides a reliable insurance release control method based on CPLD, which is used for an in-line fuze electronic safety and insurance release device to reliably release the secondary insurance, with fast recognition speed and high accuracy.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A reliable arming safety control method based on CPLD comprises the following steps:

[0009] (1) Power on the CPLD;

[0010] (2) After reset, configure the initial state of the output port, define a multi-bit shift register and assign an initial value;

[0011] (3) Delay to the start of the overload identification time window;

[0012] (4) If it is within the overload identification time window, continue to execute the following steps, otherwise the output port will maintain its original state;

[0013] (5) Sampling the overload signal at a fixed sampling frequency, and shifting and replacing the number in the shift register with the sampled value. This process will retain the latest sampled value and discard the earliest sampled value or initial value;

[0014] (6) Determine whether the shift register has been updated. If so, calculate the overload duration through the shift register; otherwise, calculate the overload duration through the sampling value;

[0015] (7) Determine whether the overload duration meets the overload validity condition. If so, continue to execute; otherwise, return to step (4);

[0016] (8) Determine the release status of the first-level safety release feedback input port. If it is released, continue to execute; otherwise, return to step (4);

[0017] (9) Output the second level safety release signal.

[0018] As a preferred embodiment of the above solution, the multi-bit shift register in step (2) calculates the overload duration by sliding the overload signal within the overload identification window.

[0019] As a preferred embodiment of the above scheme, the overload identification time window in step (3) selects a stable period of time to determine the identification starting point and the identification end point according to the ballistic overload characteristics.

[0020] As a preferred embodiment of the above solution, the overload signal in step (5) is provided to the CPLD by a low overload switch.

[0021] As a preferred embodiment of the above scheme, the overload validity condition in step (7) is determined based on the overload sampling situation and the acceptability of the release requirement.

[0022] Due to the above structure, the beneficial effects of the present invention are:

[0023] 1. Added a method to calculate the overload duration before register assignment is completed, avoiding the problem of abnormal register value initialization when CPLD is powered on.

[0024] 2. When identifying overload, select a time window in which the overload is relatively stable and reliable, and perform sliding value calculations through a small window within the time window. Compared with calculating the entire time window, this method has a shorter waiting time, processes fewer numbers, and is faster. It is also more reliable than using the segmented method. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0026] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, this embodiment provides a reliable insurance release control method based on CPLD, comprising the following steps:

[0029] (1) CPLD power-on: Provide 3.3V DC power to the CPLD;

[0030] (2) After reset, configure the initial state of the output port, define a multi-bit shift register and assign an initial value. The multi-bit shift register is used to perform sliding window sampling on the overload signal within the overload identification window to calculate the overload duration: After the CPLD reset signal is valid, configure the initial state of the output port, define a multi-bit shift register and assign an initial value of 0. The number of bits of the shift register and the sampling frequency of the overload signal determine the window size of the sliding window. To ensure timeliness, the window size of the sliding window should be smaller than the overload identification window. A suitable sampling frequency can save hardware resources while ensuring reliability. The value should be determined by comprehensively considering the above factors. In this embodiment, the value is 30;

[0031] (3) Delay to the start point of the overload identification time window: Start timing, delay to the start point of the overload identification time window, and then execute the following steps. The start point and end point of the overload identification time window are related to the ballistic overload characteristics. According to the release requirements, the start point and end point of the overload identification time window should cover the release conditions. Therefore, the overload identification time window should be based on the ballistic overload characteristics. A stable period of time should be selected to determine the identification start point and identification end point. In this embodiment, the overload identification time window start point is 0.5s, and the end point is 4s;

[0032] (4) If it is within the overload identification time window, that is, before the end of the overload identification time window, the following steps are continued, otherwise the output port will maintain its original state;

[0033] (5) Sampling the overload signal at a fixed sampling frequency, and shifting and replacing the number in the shift register with the sampling value at each sampling point. This process will retain the latest sampling value and discard the earliest sampling value or initial value: The overload signal is provided by the inertial switch. In this embodiment, a low overload switch is used. When the overload value it senses reaches a certain threshold, the low overload switch is closed and a low-level signal is input to the CPLD port. The sampling frequency is the sliding window duration divided by the number of register bits. In this embodiment, the value is 20Hz. ;

[0034] (6) Determine whether the shift register has been updated. If so, calculate the overload duration through the shift register, otherwise calculate the overload duration through the sampling value: Determine which method to use to calculate the overload duration. When the initial value in the shift register is not completely updated, scheme one is used to calculate the overload duration, otherwise scheme two is used for calculation. Scheme one: invert and accumulate the low overload switch signal level obtained from each sampling; scheme two: invert all numbers in the shift register and add them together. This step provides a method for calculating the overload duration before and after the shift register is updated, where the time for the shift register to be completely updated is the sampling frequency multiplied by the number of register bits plus the starting point of the overload identification time window, which is 2s in this embodiment;

[0035] (7) Determine whether the overload duration meets the overload validity condition. If so, continue to execute, otherwise return to step (4): Determine whether the overload duration meets the necessary conditions for release according to the value calculated in step (6). If so, continue to execute the following steps, otherwise the output port maintains the initial state unchanged. The judgment condition is determined based on the distribution of the overload switch level obtained by actual sampling and the acceptability of the release requirement. In this embodiment, it is set to be greater than or equal to 70% of the total number of bits of the shift register;

[0036] (8) Determine the release status of the first-level safety release feedback input port. If it is released, continue to execute the following steps; otherwise, return to step (4), and the output port maintains the initial state unchanged;

[0037] (9) Output the second level safety release signal.

[0038] This embodiment adds a method for calculating the overload duration before register assignment is completed, avoiding the problem of abnormal register value initialization when the CPLD is powered on. In addition, a time window with relatively stable and reliable overload is selected during overload identification, and sliding value calculation is performed through a small window within the time window. Compared with calculating the entire time window, this method has a shorter waiting time, processes fewer numbers, and is faster, and is more reliable than using the segmentation method for calculation.

[0039] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A reliable arming control method based on CPLD, characterized in that: The following steps are involved: (1) Power on the CPLD; (2) After reset, configure the initial state of the output port, define a multi-bit shift register and assign an initial value; (3) Delay to the start of the overload identification time window; (4) If it is within the overload identification time window, continue to execute the following steps, otherwise the output port will maintain its original state; (5) Sampling the overload signal at a fixed sampling frequency, and shifting and replacing the number in the shift register with the sampled value. This process will retain the latest sampled value and discard the earliest sampled value or initial value; (6) Determine whether the shift register has been updated. If so, calculate the overload duration through the shift register; otherwise, calculate the overload duration through the sampling value; (7) Determine whether the overload duration meets the overload validity condition. If so, continue to execute; otherwise, return to step (4); (8) Determine the release status of the first-level safety release feedback input port. If it is released, continue to execute; otherwise, return to step (4); (9) Output the second level safety release signal.

2. A reliable arming control method based on CPLD according to claim 1, characterized in that: The multi-bit shift register in step (2) calculates the overload duration by sliding the window value of the overload signal within the overload identification window.

3. The reliable arming control method based on CPLD according to claim 1, characterized in that: The overload recognition time window in step (3) selects a stable period of time to determine the recognition start point and recognition end point according to the ballistic overload characteristics.

4. The reliable arming control method based on CPLD according to claim 1, characterized in that: The overload signal in step (5) is provided to the CPLD by the low overload switch.

5. The reliable arming control method based on CPLD according to claim 1 is characterized in that: The overload validity condition in step (7) is determined based on the overload sampling situation and the acceptability of the release requirement.

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