Penetration fuze accurate layer metering method for identifying strong aliasing overload signal

Abstract

The invention discloses a penetration fuse accurate layer metering method for identifying a strong aliasing overload signal, and belongs to the technical field of penetration fuses. Cross-correlation calculation is carried out based on an overload signal and a half-sine function to obtain a layer envelope signal, the peak value of the layer envelope signal is used as a projectile body collision target characteristic value, an energy attenuation coefficient is calculated in real time in the penetration process, the overload signal oscillation degree in the target penetrating process is quantified, and the layer envelope signal peak value of the previous layer is multiplied by the energy attenuation coefficient, so that the vibration degree of the projectile body collision target is calculated. Therefore, the layer target identification capability of the penetration fuze in the high-speed penetration environment of the warhead with the large length-diameter ratio is improved, and the layer counting accuracy of the fuze is improved. According to the method, the problem of inaccurate layer metering caused by serious aliasing of overload signals and stress wave signals and incapability of identifying target environment change when the penetration fuze follows complex working conditions of variable wall thickness, variable spacing and the like of high-speed penetration of a large-length-diameter-ratio warhead is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of penetration fuzes, and in particular relates to an accurate layer counting method for a penetration fuze for identifying strong aliasing overload signals. Background Art

[0002] The penetration fuze is the key to the efficient destruction of multi-layer hard targets by penetrating ammunition. Its core is the adaptive detonation control technology under high overload conditions. The penetrating warhead is a weapon that uses high-strength alloy combined with ultra-high speed kinetic energy to penetrate enemy buildings and then destroy them. The penetration fuze is the intelligent brain of the penetrating warhead. The accurate explosion point control of the fuze at the predetermined position is crucial to the effect of the warhead in destroying enemy targets. At present, the penetration speed of a large aspect ratio penetrating warhead can reach 1000m / s or even higher, up to 1200m / s. It can penetrate a floor with a standard floor spacing of 3.3m within 3ms and continuously penetrate multi-layer targets in a short time. The penetration process is short, the energy release time is limited, and the superposition of overload signals and stress waves is more serious, which brings great difficulty to the fuze identification layer signal. At the same time, adding anti-penetration measures such as variable spacing and variable thickness in buildings makes it difficult for the penetration fuze to identify layer signals and cannot identify changes in the target environment under complex conditions such as variable wall thickness and variable spacing. Adaptive adjustment of the detonation strategy, resulting in inaccurate layer counting, adaptive adjustment of the detonation strategy according to changes in the target environment to achieve precise explosion point control is becoming increasingly prominent. Summary of the invention

[0003] Aiming at the problem that when a penetration fuze follows a large aspect ratio warhead to penetrate a multi-story building at high speed, the overload signal and the stress wave signal are seriously overlapped, which makes it difficult for the fuze to identify the layer signal, and it is unable to identify the target environment changes and adaptively adjust the detonation strategy under complex working conditions such as variable wall thickness and variable spacing, resulting in inaccurate layer counting, the present invention proposes a method for obtaining a layer envelope signal based on the cross-correlation calculation of the overload signal and a half-sine function, taking the layer envelope signal peak value as the projectile hitting the target characteristic value, calculating the energy attenuation coefficient in real time during the penetration process, quantifying the degree of overload signal oscillation during the target penetration process, and multiplying the layer envelope signal peak value of the previous layer by the energy attenuation coefficient as the basis for identifying the adjacent layers, thereby improving the layer target recognition capability of the penetration fuze in the high-speed penetration environment of the large aspect ratio warhead, and improving the layer counting accuracy of the fuze.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0005] The present invention proposes a method for accurately counting the layers of a penetration fuze for identifying a strong aliased overload signal, comprising the following steps:

[0006] Step 1: Set the detonation layer counter value to N;

[0007] Step 2: Calculate the average value of the overload signal and collect the overload signal a at a sampling rate of 10us(i) , accumulate and sum the overload signals with a window length of M and calculate the average value as adbase_val;

[0008] Step 3: Overload signal preprocessing

[0009] Overload signal a (i) The difference between the average value adbase_val and the absolute value is taken, and the dynamic sliding window filtering is performed with a window length of M to obtain as (i) , and then square it to get as 2 (i) ;

[0010] Step 4: First layer triggering and extracting overload signal layer envelope peak value;

[0011] Step 4.1: Identify the first layer trigger

[0012] The overload signal after preprocessing in step 3 is as (i) If the trigger threshold gate1 is greater than or equal to m times in a row, the first layer trigger is valid, and the peak time T0 of the current layer envelope signal is the starting time, and the process goes to step 4.2, otherwise it goes to step 3; the trigger threshold gate1 is usually between one third and one half of the peak value of the overload signal.

[0013] Step 4.2: extracting the layer envelope peak of the first layer overload signal;

[0014] After the first layer trigger is recognized to be effective in step 4.1, within the time window of T0 to T0+2ms, the overload signal as pre-processed in step 3 is processed with a window length of M. 2 (i) The layer envelope value c is obtained by cross-correlation operation with the half-sine function (i) , real-time selection of c (i) The maximum value in is taken as the layer envelope peak value max_front, the layer envelope value maxend_val at the end of the time window is recorded, the energy attenuation coefficient is calculated, and then step 7 is executed;

[0015] The energy attenuation coefficient G is calculated using formula (1);

[0016]

[0017] Where a is a constant. When a takes a smaller value, it can smooth out the drastic change in energy. Therefore, proper selection of a can adapt to the penetration of different target thicknesses.

[0018] Step 5: Current layer decision control

[0019] Step 5.1 Extract the layer envelope peak value of the current layer overload signal

[0020] In the time window of T0~T0+2ms, with the sliding window length as M, the overload signal as preprocessed in step 3 is 2 ( i ) and the half-sine function to obtain the layer envelope value c (i) , real-time selection of c (i) The maximum value in is the layer envelope peak value maxcourent_vax and its corresponding time is T 1， Record the envelope value maxcourentend_val at the end of the time window;

[0021] Step 5.2 Current layer trigger identification

[0022] If the current layer envelope peak value maxcourent_vax ≥ (max_front * energy attenuation coefficient G), the current layer triggers recognition, updates max_front = maxcourent_vax, maxend_val = maxcourentend_val, T0 = T1, calculates the energy attenuation coefficient G, and executes step 6, otherwise repeats step 5;

[0023] Step 6: Delay between layers

[0024] Delay 2ms from the peak time T0 of the current layer envelope signal, and enter step 7 after the 2ms delay time is up;

[0025] Step 7: Output layer-counting detonation signal

[0026] If the detonation layer counter value (N-1) = 0, the detonation layer is reached, and a detonation layer counter signal is output, and the process ends;

[0027] If the detonation layer counter value (N-1)≠0, the current layer is a non-detonation layer, and the process returns to step 5.

[0028] Compared with the prior art, the invention provides a method for accurately counting the layers of a penetration fuze by identifying strong aliasing overload signals, which has the following beneficial effects:

[0029] (1) The present invention pre-processes the overload signal by taking the absolute value of the overload signal and then performing a sliding window filter and a square operation, thereby amplifying the difference in amplitude between the overload signal and the stress wave signal;

[0030] (2) The method proposed in the present invention performs a cross-correlation operation on the pre-processed overload signal and the half-sine function, extracts the layer envelope signal of the overload signal, takes the layer envelope signal peak value as the characteristic value of the projectile hitting the target, calculates the energy attenuation coefficient in real time during the penetration process, quantifies the degree of overload signal oscillation during the penetration process, and multiplies the layer envelope signal peak value of the previous layer by the energy attenuation coefficient as the basis for identifying adjacent layers, thereby improving the layer target recognition capability of the penetration fuze in the high-speed penetration environment of the large aspect ratio warhead and improving the layer counting accuracy of the fuze. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the overload signal output by the acceleration sensor at the fuse part in the embodiment of the present invention;

[0032] Figure 2 This is the result of 12-story detonation based on the overload signal in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In one embodiment of the present invention, a projectile with a length of 2.2 m penetrates 12 layers of C40 target plates (layer spacing of 3 meters) at an initial speed of 1000 m / s, and the fuze is required to detonate within 3 meters after hitting the 12 targets. The overload signal output by the acceleration sensor at the fuze part is as follows: Figure 1 The present invention is based on a specific implementation method of a penetration fuze accurate layer counting method for identifying strong aliasing overload signals, as shown in FIG. Figure 2 As shown, the specific steps include:

[0034] Step 1: Set the detonation layer counter value to N=12;

[0035] Step 2: Calculate the average value of the overload signal and collect the overload signal a at a sampling rate of 10us (i) , accumulate and sum the overload signals with a window length M of 100 and then calculate the average value as adbase_val;

[0036] Step 3: Overload signal preprocessing;

[0037] Overload signal a (i) After taking the absolute value of the difference from the average value adbase_val, dynamic sliding window filtering is performed with a window length of M of 100 to obtain as (i) , and then square it to get as 2 (i) ;

[0038] Step 4: First layer triggering and extracting overload signal layer envelope peak

[0039] Step 4.1: Identify the first layer trigger

[0040] The overload signal after preprocessing in step 3 is as (i)If the value is ≥ 6000g for m times (m=5) in a row, the first layer trigger is valid, and the peak time T0 of the current layer envelope signal is the starting time, and the process goes to step 4.2, otherwise it goes to step 3;

[0041] Step 4.2: Extract the layer envelope peak of the first layer overload signal

[0042] After the first layer trigger is recognized to be effective in step 4.1, within the time window of T0 to T0+2ms, the overload signal as pre-processed in step 3 is processed with a sliding window length of M=100. 2 (i) The layer envelope value c is obtained by cross-correlation operation with the half-sine function (i) , real-time selection of c (i) The maximum value in is the layer envelope peak value max_front, record the layer envelope value maxend_val at the end of the time window, calculate the energy attenuation coefficient, and then execute step 7;

[0043] The energy attenuation coefficient G is calculated using formula (1);

[0044]

[0045] Where a is a constant (0.5 to 0.9). When a takes a smaller value, the drastic change of energy can be smoothed. Figure 1 For overload signal data, select a=0.6.

[0046] Step 5: Current layer decision control

[0047] Step 5.1 Extract the layer envelope peak value of the current layer overload signal

[0048] In the time window of T0~T0+2ms, with the sliding window length of M=100, the overload signal as preprocessed in step 3 is 2 (i) Perform cross-correlation operation with the half-sine function to obtain the layer envelope value c (i) , real-time selection of c (i) The maximum value in is the layer envelope peak value maxcourent_vax and its corresponding time is T1, and the envelope value maxcourentend_val at the end of the time window is recorded;

[0049] Step 5.2 Current layer trigger identification

[0050] If it is determined that the envelope peak value of the current layer maxcourent_vax ≥ (max_front * energy attenuation coefficient G), the current layer triggers recognition, updates max_front = maxcourent_vax, maxend_val = maxcourentend_val, T0 = T1, calculates the energy attenuation coefficient G, and executes step 6, otherwise repeats step 5;

[0051] Step 6: Delay between layers

[0052] Delay 2ms from the peak time T0 of the current layer envelope signal, and enter step 7 after the 2ms delay time is reached;

[0053] Step 7: Output layer-counting detonation signal

[0054] If the detonation layer counting counter value (N-1) = 0, the detonation layer is reached, a counting detonation signal is output, and the process ends.

[0055] If the detonation layer counter value (N-1)≠0, the current layer is a non-detonation layer, and the process returns to step 5.

Claims

1. A method for accurately counting layers of a penetration fuze by identifying strong aliasing overload signals, characterized in that: The following steps are involved: Step 1: Set the detonation layer counter value to N; Step 2: Calculate the average value of the overload signal, collect the overload signal, accumulate and sum the overload signals with a window length of M, and then calculate the average value as adbase_val; Step 3: Overload signal preprocessing; Overload signal a (i) The difference between the average value adbase_val and the absolute value is taken, and the dynamic sliding window filtering is performed with a window length of M to obtain as (i) , and then square it to get as 2 (i) ; Step 4: First layer triggering and extracting overload signal layer envelope peak value; Step 4.1: Identify the first layer trigger The overload signal after preprocessing in step 3 is as (i) If gate1 is greater than or equal to m times in a row, the first layer trigger is valid, and the peak time T0 of the current layer envelope signal is the starting time, and the process goes to step 4.2, otherwise it goes to step 3; Step 4.2: extracting the layer envelope peak of the first layer overload signal; After the first layer trigger is recognized to be effective in step 4.1, within the time window of T0 to T0+2ms, the overload signal as pre-processed in step 3 is processed with a window length of M. 2 (i) The layer envelope value c is obtained by cross-correlation operation with the half-sine function (i) , real-time selection of c (i) The maximum value in is taken as the layer envelope peak value max_front, the layer envelope value maxend_val at the end of the time window is recorded, the energy attenuation coefficient is calculated, and then step 7 is executed; Step 5: Current layer decision control; Step 5.1 Extract the layer envelope peak value of the current layer overload signal In the time window of T0~T0+2ms, with the sliding window length as M, the overload signal as preprocessed in step 3 is 2 ( i ) and the half-sine function to obtain the layer envelope value c (i) , real-time selection of c (i) The maximum value in is the layer envelope peak value maxcourent_vax and its corresponding time is T 1， Record the envelope value maxcourentend_val at the end of the time window; Step 5.2 Current layer trigger identification If the current layer envelope peak value maxcourent_vax ≥ (max_front * energy attenuation coefficient G), the current layer triggers recognition, updates max_front = maxcourent_vax, maxend_val = maxcourentend_val, T0 = T1, calculates the energy attenuation coefficient G, and executes step 6, otherwise repeats step 5; Step 6: Delay between layers Delay 2ms from the peak time T0 of the current layer envelope signal, and enter step 7 after the 2ms delay time is up; Step 7: Output layer-counting detonation signal If the detonation layer counter value (N-1) = 0, the detonation layer is reached, and a detonation layer counter signal is output, and the process ends; If the detonation layer counter value (N-1)≠0, the current layer is a non-detonation layer, and the process returns to step 5.

2. The method for accurately counting layers of a penetration fuze by identifying strong aliasing overload signals as claimed in claim 1, characterized in that: In step 2, the overload signal is collected at a sampling rate of 10us.

3. The method for accurately counting layers of a penetration fuze by identifying strong aliasing overload signals as claimed in claim 1, characterized in that: In step 4, the trigger threshold gate1 is usually between one half and one third of the peak value of the overload signal.

4. The method for accurately counting layers of a penetration fuze by identifying strong aliasing overload signals as claimed in claim 1, characterized in that: The energy attenuation coefficient G is calculated using formula (1); Where a is a constant.

5. The method for accurately counting layers of a penetration fuze by identifying strong aliasing overload signals as claimed in claim 4, characterized in that: a＝0.5～0.9。

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