Parameter testing device and method based on resistive film

Abstract

The invention provides a parameter testing device and method based on a resistive film, and belongs to the technical field of mechanical experiments and digital measurement, and the device comprises two layers of resistive film sensors which are arranged according to a preset distance; each layer of resistive film sensor comprises a film resistance net and a resistance net signal processing circuit; the thin-film resistance net adopts parallel resistance wire arrays prepared on the front surface and the back surface of a thin-film medium respectively to form a crisscross net-shaped structure; and the analysis module is used for determining the speed and the direction of the projectile according to the on-off state identified by the resistance net signal processing circuit, the shot damage image of each thin-film resistance net and the launching starting point of the projectile when the projectile impacts and penetrates through the thin-film resistance nets. Through a physical logic mode, impact time information is obtained within a microsecond error, information of an impact position is obtained within a hundred-micrometer error, and the accuracy of bullet impact speed and direction parameter testing is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical experiments and digital measurement, and in particular to a parameter testing device and method based on a resistance film. Background Art

[0002] Light gas gun hypervelocity impact tests are an important means of evaluating the performance of test sample materials against hypervelocity impacts. The velocity and direction of the projectile are crucial parameters for analyzing the effects of hypervelocity impact on materials, and therefore require accurate measurement of these parameters. The projectiles used in light gas gun hypervelocity impact tests are typically millimeter-sized, made of both metal and non-metal materials, and typically launched at speeds of several thousand meters per second. These projectiles may deviate from the launch axis to a certain extent, making conventional testing methods difficult to fully adapt to these experimental conditions.

[0003] Currently, the methods commonly used to measure the velocity of light gas cannon projectiles include: magnetic induction velocity measurement. When a projectile passes through a coil, an induced current generates a change in the magnetic field. Two coils are set at a certain distance, and the time it takes for the projectile to pass through the coils is measured to determine the projectile's flight speed. This detection method has a simple structure, but it is mainly suitable for testing projectiles made of conductive materials such as metal; otherwise, no induction signal will be detected. High-speed camera velocity measurement uses a camera to capture high-speed images of the projectile's flight trajectory. The projectile's flight speed is calculated based on the projectile's position in each frame and the camera's frame rate. This method provides excellent visualization, but for high-precision measurement of small, high-speed projectiles, it places particularly high demands on the camera's field of view, frame rate, and resolution. The equipment is very expensive, making its application costly. Laser beam velocity measurement uses a laser beam method. When a projectile passes through a beam, it blocks the light passing through that path. A photodetector senses the change in light intensity, and the projectile's velocity is calculated based on the time difference between the two beams. This method offers high accuracy, but requires high collimation of the projectile launch. If the projectile deviates significantly from the axis, velocity measurement may fail.

[0004] Therefore, the present invention proposes a parameter testing device and method based on a resistor film. Summary of the Invention

[0005] The present invention provides a parameter testing device and method based on a resistor film, which are used to solve the above-mentioned technical problems.

[0006] The present invention provides a parameter testing device based on a resistor film, comprising:

[0007] Two-layer resistive thin film sensor, wherein the two-layer resistive thin film sensor is placed at a preset distance;

[0008] Each layer of the resistive thin film sensor includes: a thin film resistor network and a resistor network signal processing circuit;

[0009] The thin film resistor network is formed by preparing parallel resistance wire arrays on the front and back sides of the thin film medium to form a cross-shaped mesh structure;

[0010] The resistor network signal processing circuit is used to identify the on / off status of the resistor wires in the thin film resistor network;

[0011] The analysis module is used to determine the projectile speed and projectile direction when the projectile hits and passes through the thin film resistor network based on the on-off state identified by the resistor network signal processing circuit, the damaged image of each thin film resistor network taken, and the projectile launch starting point.

[0012] Preferably, the resistance wires of the thin film resistor network are respectively connected to the multi-way selection switch chip as input signals, and one end of the resistance wire is connected to the ground signal. When the resistance wire is turned on and the multi-way selection switch is selected, the output signal is low level. When the resistance wire is turned off and the multi-way selection switch is selected, the output signal is connected to the power supply voltage through the pull-up resistor, and the output signal is high level.

[0013] The output signal of the multi-way selection switch chip is connected to the pin of the FPGA processor, and the processor realizes parallel acquisition of the output signal and identifies the level state.

[0014] Preferably, the analysis module includes:

[0015] The signal statistics unit is used to identify the first signal set X1={n1 t1 ...n1 tm}, where n1 t1 、n1 tm They represent the number of broken resistor wires in the first layer of thin film resistor network at time t1 and time tm respectively;

[0016] According to the resistor network signal processing circuit, the second signal set X2={n2 t1 ...n2 tu}, where n2 t1 、n2 tm They represent the number of broken resistor wires in the second layer of thin film resistor network at the t1th and tuth moments respectively;

[0017] Stability analysis unit, for analyzing the first signal set X1 = {n1 t1 ...n1 tm} captures the first moment sc1 when the number of resistor wire breaks begins to stabilize and changes, and the second moment sc2 when the number of resistor wire breaks changes and ends to stabilize;

[0018] From the second signal set X2 = {n2 t1 ...n2 tu} captures the third moment sc3 when the number of resistor wire breaks begins to stabilize and then changes, and the fourth moment sc4 when the number of resistor wire breaks begins to stabilize and then changes;

[0019] A probability analysis unit is used to draw a curve of the number of disconnected resistor wires in the signal set and divide the curve according to the curve attributes to determine the probability of intermittent connection;

[0020] a time period adjustment unit, configured to determine an adjustment amount corresponding to a time point at which the intermittent connection probability changes to a time point at which stability ends, and adjust the second time point sc2 and the fourth time point sc4 to obtain a corresponding fifth time point sc5 and a corresponding sixth time point sc6;

[0021] According to the first time period T1 of the first moment sc1 and the third moment sc3, the second time period T2 of the fifth moment sc5 and the sixth moment sc6 is adjusted to obtain a reference time period T3;

[0022] The intra-net motion determination unit is used to obtain the motion speed and motion direction of the projectile between the two thin film resistor nets based on the reference time period T3 and the first position point penetrating the first layer of thin film resistor net and the second position point penetrating the second layer of thin film resistor net.

[0023] Preferably, the analysis module further includes:

[0024] an energy determination unit, configured to obtain a captured damaged image of the first layer of thin film resistor network, and perform burr analysis on the damaged image to determine the impact energy of the projectile on the first layer of thin film resistor network;

[0025] An initial determination unit, configured to represent the projectile launch starting point, the first position point at which the projectile penetrates the first layer of thin-film resistor network, and the second position point at which the projectile penetrates the second layer of thin-film resistor network in a preset coordinate system, and determine the projectile's initial velocity, initial direction, and direction linkage line;

[0026] A factor acquisition unit is used to represent the impact damage of the damaged image in a preset coordinate system, and to perform 1° cutting along the direction of movement according to the intersection of the direction linkage lines, and to obtain the energy attenuation factor at each 1° angle in combination with the impact energy;

[0027] Inferring a reference velocity at which the projectile hits the first thin film resistor layer based on the energy attenuation factor;

[0028] A verification unit is configured to verify the initial speed according to the reference speed.

[0029] Preferably, the probability analysis unit includes:

[0030] The curve fitting subunit is used to perform curve fitting on the preprocessed signal using a polynomial fitting method to obtain a continuous fitting curve;

[0031] The residual calculation subunit is used to calculate the residual between the actual signal value and the fitting curve as a measure of signal fluctuation;

[0032] The curve division sub-unit is used to divide the entire curve into multiple segments with different characteristics according to the change rate and trend of the curve, wherein the segments with different characteristics include: stable segment, rising segment and fluctuating segment;

[0033] A threshold determination subunit is used to calculate the standard deviation of the residual within the curve segment and set a dynamic threshold based on a multiple of the standard deviation;

[0034] The probability determination subunit is used to count the proportion of data points whose residual exceeds the corresponding dynamic threshold, and combine the characteristics of the corresponding segment to obtain the intermittent connection probability of the corresponding segment.

[0035] Preferably, the threshold determination subunit is used to:

[0036]

[0037] Among them, YZ is the corresponding dynamic threshold; σ1 is the standard deviation of the residual in the corresponding curve segment; K1 and K2 are adjustable parameters; median(|r i -median(r)|) represents the median of the absolute deviations of the residuals with respect to the median.

[0038] Preferably, the probability determination subunit is used to:

[0039]

[0040] Where P represents the probability of intermittent connection; w1, w2, and w3 represent the factors affecting the probability of segment characteristics; NB represents the number of fluctuation points in the fluctuation segment; M1 represents the total number of points in the fluctuation segment; Tb represents the total duration of the fluctuation point in the fluctuation segment; T M1 Indicates the total duration of the fluctuation segment.

[0041] The present invention provides a parameter testing method based on a resistor film, comprising:

[0042] Step 1: Identify the on / off status of the resistor wires on the thin film resistor network based on the resistor network signal processing circuit;

[0043] Step 2: When the projectile hits and passes through the thin film resistor network, the projectile speed and projectile direction are determined based on the on-off state identified by the resistor network signal processing circuit, the damaged image of each thin film resistor network taken, and the starting point of the projectile launch. The thin film resistor network and the resistor network signal processing circuit constitute a resistor thin film sensor, and the resistor thin film sensor has two layers, which are placed at a preset distance. The thin film resistor network uses parallel resistance wire arrays prepared on the front and back sides of the thin film medium to form a cross-shaped mesh structure.

[0044] Preferably, determining the projectile velocity and projectile direction includes:

[0045] According to the resistor network signal processing circuit, the first signal set X1={n1 t1 ...n1 tm}, where n1 t1 、n1 tm They represent the number of broken resistor wires in the first layer of thin film resistor network at time t1 and time tm respectively;

[0046] According to the resistor network signal processing circuit, the second signal set X2={n2 t1 ...n2 tu}, where n2 t1 、n2 tm They represent the number of broken resistor wires in the second layer of thin film resistor network at the t1th and tuth moments respectively;

[0047] From the first signal set X1={n1 t1 ...n1 tm} captures the first moment sc1 when the number of resistor wire breaks begins to stabilize and changes, and the second moment sc2 when the number of resistor wire breaks changes and ends to stabilize;

[0048] From the second signal set X2 = {n2 t1 ...n2 tu} captures the third moment sc3 when the number of resistor wire breaks begins to stabilize and then changes, and the fourth moment sc4 when the number of resistor wire breaks begins to stabilize and then changes;

[0049] Draw a curve of the number of resistor wire breaks in the signal set, and divide the curve according to the curve attributes to determine the probability of intermittent connection;

[0050] Determine the adjustment amount corresponding to the moment when the intermittent connection probability changes to the moment when stability ends, and adjust the second moment sc2 and the fourth moment sc4 to obtain the corresponding fifth moment sc5 and the sixth moment sc6;

[0051] According to the first time period T1 of the first moment sc1 and the third moment sc3, the second time period T2 of the fifth moment sc5 and the sixth moment sc6 is adjusted to obtain a reference time period T3;

[0052] According to the reference time period T3 and the first position point penetrating the first layer of thin film resistor network and the second position point penetrating the second layer of thin film resistor network, the moving speed and moving direction of the projectile between the two layers of thin film resistor network are obtained.

[0053] Preferably, determining the projectile speed and projectile direction further includes:

[0054] Acquire a damaged image of the first layer of thin film resistor network, and perform burr analysis on the damaged image to determine the impact energy of the projectile on the first layer of thin film resistor network;

[0055] The projectile launch starting point, the first position point of penetrating the first layer of thin film resistor network, and the second position point of penetrating the second layer of thin film resistor network are reflected in a preset coordinate system to determine the projectile's initial speed, initial direction, and direction linkage line;

[0056] The impact damage of the damaged image is reflected in a preset coordinate system, and 1° cuts are made along the direction of movement according to the intersection points of the directional linkage lines, and the energy attenuation factor at each 1° angle is obtained in combination with the impact energy;

[0057] Inferring a reference velocity at which the projectile hits the first thin film resistor layer based on the energy attenuation factor;

[0058] The initial speed is verified according to the reference speed.

[0059] Compared with the prior art, the present invention has the following advantages:

[0060] The speed and direction information of the projectile are tested by arranging two layers of resistive thin film sensors at a certain distance. Through physical logic, the impact time information is obtained within a microsecond error, and the impact position information is obtained within a hundred microns error, ensuring the accuracy of the projectile impact speed and direction parameter tests.

[0061] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0062] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0064] Figure 1 1 is a structural diagram of a parameter testing device based on a resistor film according to an embodiment of the present invention;

[0065] Figure 2 This is a flow chart of a parameter testing method based on a resistor film according to an embodiment of the present invention;

[0066] Figure 3 A structural diagram of a test device according to an embodiment of the present invention;

[0067] Figure 4 Schematic diagram of the thin film resistor network structure in an embodiment of the present invention;

[0068] Figure 5 A structural design diagram of a resistor network signal processing circuit according to an embodiment of the present invention;

[0069] Figure 6 This is a diagram of a method for testing projectile velocity and direction parameters based on a resistive film sensor in an embodiment of the present invention. DETAILED DESCRIPTION

[0070] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0071] The present invention provides a parameter testing device based on a resistance film, such as Figure 1 Shown, including:

[0072] Two-layer resistive thin film sensor, wherein the two-layer resistive thin film sensor is placed at a preset distance;

[0073] Each layer of the resistive thin film sensor includes: a thin film resistor network and a resistor network signal processing circuit;

[0074] The thin film resistor network is formed by preparing parallel resistance wire arrays on the front and back sides of the thin film medium to form a cross-shaped mesh structure;

[0075] The resistor network signal processing circuit is used to identify the on / off status of the resistor wires in the thin film resistor network;

[0076] The analysis module is used to determine the projectile speed and projectile direction when the projectile hits and passes through the thin film resistor network based on the on-off state identified by the resistor network signal processing circuit, the damaged image of each thin film resistor network taken, and the projectile launch starting point.

[0077] Preferably, the resistance wires of the thin film resistor network are respectively connected to the multi-way selection switch chip as input signals, and one end of the resistance wire is connected to the ground signal. When the resistance wire is turned on and the multi-way selection switch is selected, the output signal is low level. When the resistance wire is turned off and the multi-way selection switch is selected, the output signal is connected to the power supply voltage through the pull-up resistor, and the output signal is high level.

[0078] The output signal of the multiplexer chip is connected to the pin of the FPGA processor, and the processor realizes the parallel acquisition of the output signal and identifies the level state, such as Figure 5 shown.

[0079] The test device structure is as follows Figure 3 As shown, where: 1—thin film resistor network 1, 2—thin film resistor network 2, 3—resistance network signal processing circuit.

[0080] In the present invention, the thin film resistor network is prepared by respectively preparing parallel resistance wire arrays on the front and back sides of the thin film medium to form a cross-shaped network structure. Figure 4 This is a schematic diagram of the thin-film resistor network structure. It consists of three components: 1—the front-side resistor wire array, 2—the thin-film dielectric, and 3—the back-side resistor wire array. The thin-film dielectric can be made of a polyimide film or similar insulating film as its substrate, typically with a thickness of no more than 25 microns. The front-side resistor wire array is formed by laminating and etching the front side of the thin-film dielectric, while the back-side resistor wire array is formed by the same laminating and etching process on the back side. The front and back resistor wires are oriented orthogonally to each other, forming a cross-mesh structure. The resistor wires can be made of conductive materials such as copper and aluminum that are easily etched. To address the characteristics of millimeter-scale projectiles, the resistor wires can be designed with a width of 100 microns, a spacing of 100 microns, and a thickness of no more than 10 microns. To accommodate the requirements for projectile deviation from the axis, the thin-film resistor network is designed to have a certain effective detection area. For example, if the detection area is 20 cm × 20 cm, 1000 resistor wires can be designed per side.

[0081] In this embodiment, the method for testing the projectile speed and direction parameters based on the resistance film sensor is as follows: Figure 6 At the front and rear ends of the projectile launch path, a resistive film sensor 1 and a resistive film sensor 2 are placed at a certain interval H, respectively.

[0082] The projectile velocity test method is to calculate the distance between the two impact points based on the position coordinates of the two impact points on the resistive film sensor 1 and the resistive film sensor 2. The movement time of the projectile between the two impact points can be calculated based on the impact time on the resistive film sensor 1 and the resistive film sensor 2. The ratio of distance to time can be used to calculate the projectile velocity.

[0083] When a projectile impacts and passes through resistive film sensor 1, causing the resistor wires on the sensor to break, the resistor network signal processing circuit can detect the time T1 when the thin film resistor network breaks within a 1 microsecond period. It can also obtain the number and location of the broken resistor wires. By calculating the center coordinates of the broken resistor wire arrays on both sides of the orthogonal surface of the resistive film sensor, the impact location (X1, Y1, Z1) of the resistive film sensor 1 can be determined. For example, if there are N resistor wires on both sides of the resistive film sensor, the starting location of the front resistor wire array is the n1th wire, and the number of consecutive broken wires is a. The starting location of the back resistor wire array is the m1th wire, and the number of consecutive broken wires is b. The impact point is calculated as shown in the following formula.

[0084] X1=(n1+((a-1) / 2)-N / 2)×p

[0085] Y1=(m1+((b-1) / 2)-N / 2)×p

[0086] Where: N is the number of resistance wires on each side; p is the center distance between two resistance wires.

[0087] The projectile continues to impact and penetrate resistive film sensor 2, breaking the resistor wires on the sensor. The resistor network signal processing circuit measures the time T2 at which the thin film resistor network breaks, and the collision location (X2, Y2, Z2). For example, if the sensor has N resistor wires on both sides, the front resistor array starts breaking at the n2th wire, with c consecutive wires broken. The back resistor array starts breaking at the m2th wire, with d consecutive wires broken. The collision location is calculated as shown in the following formula.

[0088] X2=(n2+((c-1) / 2)-N / 2)×p

[0089] Y2=(m2+((d-1) / 2)-N / 2)×p

[0090] The distance S between the two impact points can be calculated from the position coordinates of the two impact points on the resistive film sensor 1 and the resistive film sensor 2, as shown in the following formula.

[0091]

[0092] Wherein: (X1, Y1, Z1)—the coordinates of the impact point of the resistive film sensor 1, Z1=0; (X2, Y2, Z2)—the coordinates of the impact point of the resistive film sensor 2, Z2=H.

[0093] Then the projectile velocity V can be expressed as follows.

[0094]

[0095] The projectile direction is determined by the coordinates of the impact point (X1, Y1, Z1) on the first resistive film and the impact point (X2, Y2, Z2) on the second resistive film. The projectile impact angle can be expressed as:

[0096]

[0097] Among them: α is the angle between the projectile's flight direction and the X-axis; β is the angle between the projectile's flight direction and the Y-axis; θ is the angle between the projectile's flight direction and the Z-axis.

[0098] In this embodiment, a thin film resistor network and a high-speed on-off identification method of the resistor network signal are used to identify the information characterizing the passage of the projectile, such as the time when the resistor wire is broken and the position of the broken wire. An array of parallel resistor wires is prepared on the front and back sides of the thin film medium to form a cross-shaped mesh structure. The information of the passage of the projectile is characterized by the information of the resistor wire broken wire. A circuit design that can quickly identify the on-off state of the resistor wire on the thin film resistor network is used to obtain the information of the resistor wire broken wire and the position of the broken wire. Two resistor film sensors are used to respectively obtain the resistor wire broken wire time and the position of the broken wire of the thin film resistor network, and calculate and obtain the speed and direction information of the projectile.

[0099] In this embodiment, the damage image is a visual record of the surface damage of the thin-film resistor mesh after the projectile impacts and penetrates it. The image contains key information such as the penetration location and damage form, which can be used to accurately calculate the projectile trajectory and velocity. A high-speed camera with a frame rate of ≥100,000 fps is used to record the deformation and damage process of the resistor mesh at the moment of projectile impact.

[0100] The beneficial effects of the above technical solution are: by arranging two layers of resistive thin film sensors at a certain interval, the speed and direction information of the projectile can be tested, and through physical logic, the impact time information can be obtained within a microsecond error, and the impact position information can be obtained within a hundred microns error, thereby ensuring the accuracy of the projectile impact speed and direction parameter tests.

[0101] The present invention provides a parameter testing device based on a resistor film, wherein the analysis module comprises:

[0102] The signal statistics unit is used to identify the first signal set X1={n1 t1 ...n1 tm}, where n1 t1 、n1 tm They represent the number of broken resistor wires in the first layer of thin film resistor network at time t1 and time tm respectively;

[0103] According to the resistor network signal processing circuit, the second signal set X2={n2 t1 ...n2 tu}, where n2 t1 、n2 tm They represent the number of broken resistor wires in the second layer of thin film resistor network at the t1th and tuth moments respectively;

[0104] Stability analysis unit, for analyzing the first signal set X1 = {n1 t1 ...n1 tm} captures the first moment sc1 when the number of resistor wire breaks begins to stabilize and changes, and the second moment sc2 when the number of resistor wire breaks changes and ends to stabilize;

[0105] From the second signal set X2 = {n2 t1 ...n2 tu} captures the third moment sc3 when the number of resistor wire breaks begins to stabilize and then changes, and the fourth moment sc4 when the number of resistor wire breaks begins to stabilize and then changes;

[0106] A probability analysis unit is used to draw a curve of the number of disconnected resistor wires in the signal set and divide the curve according to the curve attributes to determine the probability of intermittent connection;

[0107] a time period adjustment unit, configured to determine an adjustment amount corresponding to a time point at which the intermittent connection probability changes to a time point at which stability ends, and adjust the second time point sc2 and the fourth time point sc4 to obtain a corresponding fifth time point sc5 and a corresponding sixth time point sc6;

[0108] According to the first time period T1 of the first moment sc1 and the third moment sc3, the second time period T2 of the fifth moment sc5 and the sixth moment sc6 is adjusted to obtain a reference time period T3;

[0109] The intra-net motion determination unit is used to obtain the motion speed and motion direction of the projectile between the two thin film resistor nets based on the reference time period T3 and the first position point penetrating the first layer of thin film resistor net and the second position point penetrating the second layer of thin film resistor net.

[0110] In this embodiment, the first signal set is a data set of the number of resistor wire breaks that changes with time from the time the projectile is ready to launch to the time it penetrates the first layer of the resistor network. Time t1 is the system startup time, t1=0ns, and time tm is the time when the last wire of the first layer of the resistor network breaks, tm=0.021ns. In this process, after the projectile penetrates the resistor network, some resistor wires are between the disconnected and non-disconnected stages. At this time, there will be repeated signal jumps, so there will be a fluctuation segment.

[0111] For example, the first signal set is: {t1: 5 roots...tm: 32 roots}, and the required curve is obtained by plotting the number of signals in the signal set in chronological order.

[0112] In this embodiment, sc1 is the moment when the number of broken wires in the first layer of the resistor network begins to change (i.e., the moment when the projectile begins to contact the resistor network).

[0113] sc2: The moment when the number of broken wires in the first layer of the resistor network stops changing and stabilizes (i.e., the moment when the projectile completely passes through the resistor network).

[0114] sc3, sc4: The start and end change moments corresponding to the second layer of resistance network.

[0115] The first layer of resistor network:

[0116] sc1=10ns (the time when the number of disconnections increases from 0 to 5)

[0117] sc2 = 80ns (when the number of broken wires stabilizes at 32)

[0118] The second layer of resistor network:

[0119] sc3=100ns (the time when the number of disconnections increases from 0 to 8)

[0120] sc4=179ns (when the number of broken wires stabilizes at 45)

[0121] The curve is divided into a stable section (the number of broken lines remains unchanged), a changing section (the number of broken lines increases rapidly) and a fluctuating section (the intermittent connection area).

[0122] Adjustment amount: time correction value calculated based on the probability of intermittent connection, Δt = P × k (k is the adjustment coefficient, set to 0.001s).

[0123] sc5, sc6: adjusted final time points, used to replace the original sc2 and sc4.

[0124] T1: The theoretical time difference between the projectile reaching the two layers of resistance network, T1 = sc3 - sc1.

[0125] T2: The actual time difference calculated based on the adjusted time point, T2 = sc6 - sc5.

[0126] T3: Corrected reference time period, T3 = T2 × (T1 / T2_ideal), used to eliminate system errors, T2_ideal is the ideal value of T2.

[0127] Velocity calculation: v = d / T3 (d is the actual track length between two points on the two-layer resistor network).

[0128] Direction calculation: Calculate the direction vector based on the coordinate difference of the damaged center point of the two layers of resistance network.

[0129] The beneficial effects of the above technical solution are: completely capturing the changes in the number of electrical signals during the projectile penetration process, providing basic data for subsequent analysis, accurately determining the time interval for the projectile to pass through each layer of the resistance network, providing key time parameters for subsequent speed calculations, quantitatively evaluating signal quality, identifying intermittent connection problems that may affect measurement accuracy, providing a scientific basis for time point adjustment, avoiding measurement errors caused by signal fluctuations, compensating for time measurement deviations caused by intermittent connections, improving the accuracy of time parameters, and effectively eliminating errors caused by intermittent connections and system delays through multi-parameter collaborative correction.

[0130] The present invention provides a parameter testing device based on a resistor film, wherein the analysis module further includes:

[0131] an energy determination unit, configured to obtain a captured damaged image of the first layer of thin film resistor network, and perform burr analysis on the damaged image to determine the impact energy of the projectile on the first layer of thin film resistor network;

[0132] An initial determination unit, configured to represent the projectile launch starting point, the first position point at which the projectile penetrates the first layer of thin-film resistor network, and the second position point at which the projectile penetrates the second layer of thin-film resistor network in a preset coordinate system, and determine the projectile's initial velocity, initial direction, and direction linkage line;

[0133] A factor acquisition unit is used to represent the impact damage of the damaged image in a preset coordinate system, and to perform 1° cutting along the direction of movement according to the intersection of the direction linkage lines, and to obtain the energy attenuation factor at each 1° angle in combination with the impact energy;

[0134] Inferring a reference velocity at which the projectile hits the first thin film resistor layer based on the energy attenuation factor;

[0135] A verification unit is configured to verify the initial speed according to the reference speed.

[0136] In this embodiment, an edge detection algorithm is used to identify damaged images, measure the size of the damaged area, determine the caliber or energy of the projectile (the damaged diameter is positively correlated with the kinetic energy of the projectile), analyze the extension direction of the broken resistance wire, and assist in determining the projectile's incident angle (especially in non-vertical incidence scenarios).

[0137] In this embodiment, burr analysis analyzes irregular details along the damaged edges of a damaged image. During image processing, edge detection algorithms (such as the Canny operator) are used to extract the outline of the damaged area. The degree of burrs is quantified by calculating features such as the tortuosity and sharpness of the outline edge. For example, the rougher the damaged edge and the more sharp protrusions it has, the higher the burr value.

[0138] Impact Energy: The kinetic energy of a projectile when it strikes the first layer of thin-film resistor mesh. This value is calculated from burr analysis results by establishing an empirical model or physical model (such as the damage area-energy relationship based on material mechanics) that correlates burr severity with impact energy.

[0139] Preset Coordinate System: A manually defined three-dimensional coordinate system used to uniformly describe the position of each point on a projectile's trajectory. For example, a coordinate system is established with the center of the projectile launcher as the origin, the horizontal rightward direction as the positive X-axis, the vertical upward direction as the positive Y-axis, and the projectile launch direction as the positive Z-axis.

[0140] First and second positions: In the preset coordinate system, the specific coordinates of the points where the projectile penetrates the first and second thin-film resistor mesh layers. For example, if the coordinates of the first position are (10, 5, 200), it means that the projectile is 10 mm from the origin in the X-axis direction, 5 mm in the Y-axis direction, and 200 mm in the Z-axis direction; the coordinates of the second position are (10, 5, 201).

[0141] Initial Direction: The direction of motion of the projectile at the moment of launch. This direction vector is determined by the coordinate difference between the first position point and the launch starting point, and then normalized. For example, if the launch starting point is (0,0,0) and the first position point is (10,5,200), the direction vector is (10,5,200). After normalization, the initial direction vector is obtained.

[0142] Direction linkage line: In the preset coordinate system, the straight line connecting the projectile launch starting point and the second position point represents the extension line of the approximate movement direction of the projectile between the two layers of resistance network.

[0143] Impact damage is reflected in a preset coordinate system: the actual location information of the damaged area of ​​the resistor network in the damage image is converted to the preset coordinate system to determine its specific position and shape in three-dimensional space. For example, through image calibration and coordinate conversion, the center of the damaged area is located at (10.2, 5.1, 200.1).

[0144] 1° cutting: Starting from the intersection of the direction linkage line and the impact damage area, the projectile movement path is divided into multiple sector-shaped areas in space at an angle of 1° along the projectile movement direction.

[0145] Energy attenuation factor: The energy attenuation coefficient calculated from the ratio of the impact energy in each 1° sector to the initial impact energy. Assuming the initial impact energy is 50 joules and the energy in a 1° sector is 48 joules, the energy attenuation factor for that sector is 0.96.

[0146] Reference velocity: Based on the energy decay factor and the kinetic energy of the projectile The velocity of the projectile when it hits the first thin-film resistor network can be calculated in reverse order. If the mass of the projectile is known to be 0.1 kg and the energy corresponding to a certain energy attenuation factor is 45 joules, the reference velocity can be calculated using the formula to be approximately 30 m / s.

[0147] Verification: Compare and analyze the reference speed with the initial speed calculated in step 2. If the difference between the two is within the allowable error range (e.g., ±5%), the initial speed calculation is considered reliable. If it is outside the error range, re-examine the calculation process or data collection process to see if there is a problem.

[0148] The beneficial effect of the above technical solution is: through burr analysis and energy attenuation calculation of the damaged image, the projectile velocity is inferred from multiple dimensions. By using the preset coordinate system and direction linkage line, combined with the penetration point information of the multi-layer resistance network, the initial direction of the projectile can be determined more accurately, and the direction measurement accuracy is improved from ±5° to ±1°. This solution establishes a correlation between the projectile impact energy, speed, and direction. It can not only measure speed and direction, but also evaluate the energy characteristics of the projectile. It can be applied to fields such as projectile performance testing and material impact resistance evaluation, expanding the function and application scope of the measurement system. Through multi-parameter verification (verification of the initial speed by the reference speed), abnormal data and errors in the measurement process can be discovered in a timely manner, misjudgment can be reduced, and the stability and reliability of the entire measurement system can be improved.

[0149] The present invention provides a parameter testing device based on a resistor film, wherein the probability analysis unit comprises:

[0150] The curve fitting subunit is used to perform curve fitting on the preprocessed signal using a polynomial fitting method to obtain a continuous fitting curve;

[0151] The residual calculation subunit is used to calculate the residual between the actual signal value and the fitting curve as a measure of signal fluctuation;

[0152] The curve division sub-unit is used to divide the entire curve into multiple segments with different characteristics according to the change rate and trend of the curve, wherein the segments with different characteristics include: stable segment, rising segment and fluctuating segment;

[0153] A threshold determination subunit is used to calculate the standard deviation of the residual within the curve segment and set a dynamic threshold based on a multiple of the standard deviation;

[0154] The probability determination subunit is used to count the proportion of data points whose residual exceeds the corresponding dynamic threshold, and combine the characteristics of the corresponding segment to obtain the intermittent connection probability of the corresponding segment.

[0155] Preferably, the threshold determination subunit is used to:

[0156]

[0157] Among them, YZ is the corresponding dynamic threshold; σ1 is the standard deviation of the residual in the corresponding curve segment; K1 and K2 are adjustable parameters; median(|r i -median(r)|) represents the median of the absolute deviations of the residuals with respect to the median.

[0158] Preferably, the probability determination subunit is used to:

[0159]

[0160] Where P represents the probability of intermittent connection; w1, w2, and w3 represent the factors affecting the probability of segment characteristics; NB represents the number of fluctuation points in the fluctuation segment; M1 represents the total number of points in the fluctuation segment; Tb represents the total duration of the fluctuation point in the fluctuation segment; T M1 Indicates the total duration of the fluctuation segment.

[0161] In this embodiment, when analyzing the resistor network signal, various interference factors (such as electromagnetic interference and mechanical vibration) may cause signal fluctuations. Using a fixed threshold alone cannot accurately distinguish between normal signal fluctuations and abnormalities such as intermittent connections. The dynamic threshold can adaptively adjust based on the signal characteristics of different curve segments, more accurately identifying signal anomalies.

[0162] Different characteristic curve segments (stable, rising, and fluctuating segments) exhibit varying degrees of signal fluctuation and patterns, requiring specific thresholds for judgment. For example, in a fluctuating segment, the signal fluctuates significantly, and a fixed threshold can lead to numerous misjudgments. Dynamic thresholds can effectively address this issue.

[0163] The formula takes into account the standard deviation σ1 of the residual, which reflects the degree of discreteness of the signal fluctuation within the curve segment. The larger the standard deviation, the more intense the signal fluctuation, and the corresponding threshold should also be higher, which is consistent with the actual signal characteristics.

[0164] K1 and K2 are adjustable parameters that can be adjusted and optimized according to specific signal characteristics and application scenarios to make the threshold calculation more in line with actual needs.

[0165] median(|r i -median(r)|) represents the median of the absolute deviations of the residuals relative to the median. It measures the signal's deviation from another perspective and complements the standard deviation to determine a reasonable threshold. By combining these two factors, a dynamic threshold that more comprehensively and accurately reflects signal fluctuations can be obtained.

[0166] The probability of intermittent connection and signal performance vary between curve segments with different characteristics (stable, rising, and fluctuating segments), so the intermittent connection probability cannot be calculated using a unified method. For example, the intermittent connection probability calculation method for a relatively stable signal segment should be different from that for a fluctuating segment with more severe fluctuations.

[0167] Calculating the probability by considering the characteristics of the curve segment can more accurately evaluate the signal quality and intermittent connection conditions, providing a reliable basis for subsequent signal processing and accurate calculation of parameters such as projectile speed and direction.

[0168] For the stable segment and rising segment, the data point ratio is multiplied by (1-w1) and (1-w2). w1 and w2 are the factors affecting the probability of segment characteristics. They can be adjusted according to actual conditions, reflecting the impact of different segment characteristics on the probability of intermittent connection.

[0169] The fluctuation segment formula incorporates parameters such as the number of fluctuation points (NB), the total number of fluctuation points (M1), the total duration of fluctuation points (Tb), and the total duration of the fluctuation segment. These parameters comprehensively reflect characteristics such as the intensity and duration of fluctuations within the fluctuation segment. The probability calculated using these parameters more accurately reflects the intermittent connection between fluctuation segments. The calculation method within the square root sign also rationally links these parameters, making the probability calculation more scientific.

[0170] In this embodiment, w1=0.1, w2=0.15, and w3=0.2.

[0171] The beneficial effects of the above technical solution are: by calculating the intermittent connection probability through dynamic thresholds and curve segment characteristics, it can more accurately identify anomalies in the signal and reduce misjudgments caused by signal fluctuations and interference. Accurate signal analysis provides a more reliable data foundation for calculating parameters such as projectile speed and direction. Because the intermittent connection probability is accurately calculated, parameters such as the timing can be more accurately adjusted (for example, adjusting the time it takes for a projectile to pass through a resistor network based on the intermittent connection probability), thereby reducing projectile measurement errors.

[0172] The present invention provides a parameter testing method based on a resistor film, such as Figure 2 Shown, including:

[0173] Step 1: Identify the on / off status of the resistor wires on the thin film resistor network based on the resistor network signal processing circuit;

[0174] Step 2: When the projectile hits and passes through the thin film resistor network, the projectile speed and projectile direction are determined based on the on-off state identified by the resistor network signal processing circuit, the damaged image of each thin film resistor network taken, and the starting point of the projectile launch. The thin film resistor network and the resistor network signal processing circuit constitute a resistor thin film sensor, and the resistor thin film sensor has two layers, which are placed at a preset distance. The thin film resistor network uses parallel resistance wire arrays prepared on the front and back sides of the thin film medium to form a cross-shaped mesh structure.

[0175] Preferably, determining the projectile velocity and projectile direction includes:

[0176] According to the resistor network signal processing circuit, the first signal set X1={n1 t1 ...n1 tm}, where n1 t1 、n1 tm They represent the number of broken resistor wires in the first layer of thin film resistor network at time t1 and time tm respectively;

[0177] According to the resistor network signal processing circuit, the second signal set X2={n2 t1 ...n2 tu}, where n2 t1 、n2 tm They represent the number of broken resistor wires in the second layer of thin film resistor network at the t1th and tuth moments respectively;

[0178] From the first signal set X1={n1 t1 ...n1 tm} captures the first moment sc1 when the number of resistor wire breaks begins to stabilize and changes, and the second moment sc2 when the number of resistor wire breaks changes and ends to stabilize;

[0179] From the second signal set X2 = {n2 t1 ...n2 tu} captures the third moment sc3 when the number of resistor wire breaks begins to stabilize and then changes, and the fourth moment sc4 when the number of resistor wire breaks begins to stabilize and then changes;

[0180] Draw a curve of the number of resistor wire breaks in the signal set, and divide the curve according to the curve attributes to determine the probability of intermittent connection;

[0181] Determine the adjustment amount corresponding to the moment when the intermittent connection probability changes to the moment when stability ends, and adjust the second moment sc2 and the fourth moment sc4 to obtain the corresponding fifth moment sc5 and the sixth moment sc6;

[0182] According to the first time period T1 of the first moment sc1 and the third moment sc3, the second time period T2 of the fifth moment sc5 and the sixth moment sc6 is adjusted to obtain a reference time period T3;

[0183] According to the reference time period T3 and the first position point penetrating the first layer of thin film resistor network and the second position point penetrating the second layer of thin film resistor network, the moving speed and moving direction of the projectile between the two layers of thin film resistor network are obtained.

[0184] Preferably, determining the projectile speed and projectile direction further includes:

[0185] Acquire a damaged image of the first layer of thin film resistor network, and perform burr analysis on the damaged image to determine the impact energy of the projectile on the first layer of thin film resistor network;

[0186] The projectile launch starting point, the first position point of penetrating the first layer of thin film resistor network, and the second position point of penetrating the second layer of thin film resistor network are reflected in a preset coordinate system to determine the projectile's initial speed, initial direction, and direction linkage line;

[0187] The impact damage of the damaged image is reflected in a preset coordinate system, and 1° cuts are made along the direction of movement according to the intersection points of the directional linkage lines, and the energy attenuation factor at each 1° angle is obtained in combination with the impact energy;

[0188] Inferring a reference velocity at which the projectile hits the first thin film resistor layer based on the energy attenuation factor;

[0189] The initial speed is verified according to the reference speed.

[0190] The beneficial effects of the above technical solution are: by arranging two layers of resistive thin film sensors at a certain interval, the speed and direction information of the projectile can be tested, and through physical logic, the impact time information can be obtained within a microsecond error, and the impact position information can be obtained within a hundred microns error, thereby ensuring the accuracy of the projectile impact speed and direction parameter tests.

[0191] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A parameter testing device based on a resistance film, characterized in that: include: Two-layer resistive thin film sensor, wherein the two-layer resistive thin film sensor is placed at a preset distance; Each layer of the resistive thin film sensor includes: a thin film resistor network and a resistor network signal processing circuit; The thin film resistor network is formed by preparing parallel resistance wire arrays on the front and back sides of the thin film medium to form a cross-shaped mesh structure; The resistor network signal processing circuit is used to identify the on / off status of the resistor wires in the thin film resistor network; The analysis module is used to determine the projectile speed and projectile direction when the projectile hits and passes through the thin film resistor network based on the on-off state identified by the resistor network signal processing circuit, the damaged image of each thin film resistor network taken, and the projectile launch starting point.

2. The parameter testing device based on the resistance film according to claim 1, characterized in that: The resistance wires of the thin film resistor network are respectively connected to the multi-way selection switch chip as input signals, and one end of the resistance wire is connected to the ground signal. When the resistance wire is turned on and the multi-way selection switch is selected, the output signal is low level. When the resistance wire is turned off and the multi-way selection switch is selected, the output signal is connected to the power supply voltage through the pull-up resistor, and the output signal is high level. The output signal of the multi-way selection switch chip is connected to the pin of the FPGA processor, and the processor realizes parallel acquisition of the output signal and identifies the level state.

3. The parameter testing device based on the resistance film according to claim 1, characterized in that: The analysis module includes: The signal statistics unit is used to identify the first signal set X1={n1 t1 ...n1 tm }, where n1 t1 、n1 tm They represent the number of broken resistor wires in the first layer of thin film resistor network at time t1 and time tm respectively; According to the resistor network signal processing circuit, the second signal set X2={n2 t1 ...n2 tu }, where n2 t1 、n2 tm They represent the number of broken resistor wires in the second layer of thin film resistor network at the t1th and tuth moments respectively; Stability analysis unit, for analyzing the first signal set X1 = {n1 t1 ...n1 tm } captures the first moment sc1 when the number of resistor wire breaks begins to stabilize and changes, and the second moment sc2 when the number of resistor wire breaks changes and ends to stabilize; From the second signal set X2 = {n2 t1 ...n2 tu } captures the third moment sc3 when the number of resistor wire breaks begins to stabilize and then changes, and the fourth moment sc4 when the number of resistor wire breaks begins to stabilize and then changes; A probability analysis unit is used to draw a curve of the number of disconnected resistor wires in the signal set and divide the curve according to the curve attributes to determine the probability of intermittent connection; a time period adjustment unit, configured to determine an adjustment amount corresponding to a time point at which the intermittent connection probability changes to a time point at which stability ends, and adjust the second time point sc2 and the fourth time point sc4 to obtain a corresponding fifth time point sc5 and a corresponding sixth time point sc6; According to the first time period T1 of the first moment sc1 and the third moment sc3, the second time period T2 of the fifth moment sc5 and the sixth moment sc6 is adjusted to obtain a reference time period T3; The intra-net motion determination unit is used to obtain the motion speed and motion direction of the projectile between the two thin film resistor nets based on the reference time period T3 and the first position point penetrating the first layer of thin film resistor net and the second position point penetrating the second layer of thin film resistor net.

4. The parameter testing device based on the resistance film according to claim 3, characterized in that: The analysis module further includes: an energy determination unit, configured to obtain a captured damaged image of the first layer of thin film resistor network, and perform burr analysis on the damaged image to determine the impact energy of the projectile on the first layer of thin film resistor network; An initial determination unit, configured to represent the projectile launch starting point, the first position point at which the projectile penetrates the first layer of thin-film resistor network, and the second position point at which the projectile penetrates the second layer of thin-film resistor network in a preset coordinate system, and determine the projectile's initial velocity, initial direction, and direction linkage line; A factor acquisition unit is used to represent the impact damage of the damaged image in a preset coordinate system, and to perform 1° cutting along the direction of movement according to the intersection of the direction linkage lines, and to obtain the energy attenuation factor at each 1° angle in combination with the impact energy; Inferring a reference velocity at which the projectile hits the first thin film resistor layer based on the energy attenuation factor; A verification unit is configured to verify the initial speed according to the reference speed.

5. The parameter testing device based on the resistance film according to claim 4, characterized in that: The probability analysis unit includes: The curve fitting subunit is used to perform curve fitting on the preprocessed signal using a polynomial fitting method to obtain a continuous fitting curve; The residual calculation subunit is used to calculate the residual between the actual signal value and the fitting curve as a measure of signal fluctuation; The curve division sub-unit is used to divide the entire curve into multiple segments with different characteristics according to the change rate and trend of the curve, wherein the segments with different characteristics include: stable segment, rising segment and fluctuating segment; A threshold determination subunit is used to calculate the standard deviation of the residual within the curve segment and set a dynamic threshold based on a multiple of the standard deviation; The probability determination subunit is used to count the proportion of data points whose residual exceeds the corresponding dynamic threshold, and combine the characteristics of the corresponding segment to obtain the intermittent connection probability of the corresponding segment.

6. The parameter testing device based on the resistance film according to claim 5, characterized in that: The threshold determination subunit is configured to: Among them, YZ is the corresponding dynamic threshold; σ1 is the standard deviation of the residual in the corresponding curve segment; K1 and K2 are adjustable parameters; median(|r i -median(r)|) represents the median of the absolute deviations of the residuals with respect to the median.

7. The parameter testing device based on the resistance film according to claim 5, characterized in that: The probability determination subunit is used to: Where P represents the probability of intermittent connection; w1, w2, and w3 represent the factors affecting the probability of segment characteristics; NB represents the number of fluctuation points in the fluctuation segment; M1 represents the total number of points in the fluctuation segment; Tb represents the total duration of the fluctuation point in the fluctuation segment; T M1 Indicates the total duration of the fluctuation segment.

8. A parameter testing method based on a resistance film, characterized in that: include: Step 1: Identify the on / off status of the resistor wires on the thin film resistor network based on the resistor network signal processing circuit; Step 2: When the projectile hits and passes through the thin film resistor network, the projectile speed and projectile direction are determined based on the on-off state identified by the resistor network signal processing circuit, the damaged image of each thin film resistor network taken, and the starting point of the projectile launch. The thin film resistor network and the resistor network signal processing circuit constitute a resistor thin film sensor, and the resistor thin film sensor has two layers, which are placed at a preset distance. The thin film resistor network uses parallel resistance wire arrays prepared on the front and back sides of the thin film medium to form a cross-shaped mesh structure.

9. The parameter testing method based on the resistance film according to claim 8, characterized in that: Determine the projectile velocity and projectile direction, including: According to the resistor network signal processing circuit, the first signal set X1={n1 t1 ...n1 tm }, where n1 t1 、n1 tm They represent the number of broken resistor wires in the first layer of thin film resistor network at time t1 and time tm respectively; According to the resistor network signal processing circuit, the second signal set X2={n2 t1 ...n2 tu }, where n2 t1 、n2 tm They represent the number of broken resistor wires in the second layer of thin film resistor network at the t1th and tuth moments respectively; From the first signal set X1={n1 t1 ...n1 tm } captures the first moment sc1 when the number of resistor wire breaks begins to stabilize and changes, and the second moment sc2 when the number of resistor wire breaks changes and ends to stabilize; From the second signal set X2 = {n2 t1 ...n2 tu } captures the third moment sc3 when the number of resistor wire breaks begins to stabilize and then changes, and the fourth moment sc4 when the number of resistor wire breaks begins to stabilize and then changes; The number of disconnected resistor wires in the signal set is plotted and divided according to the curve attributes to determine the probability of intermittent connection. Determine the adjustment amount corresponding to the moment when the intermittent connection probability changes to the moment when stability ends, and adjust the second moment sc2 and the fourth moment sc4 to obtain the corresponding fifth moment sc5 and the sixth moment sc6; According to the first time period T1 of the first moment sc1 and the third moment sc3, the second time period T2 of the fifth moment sc5 and the sixth moment sc6 is adjusted to obtain a reference time period T3; According to the reference time period T3 and the first position point penetrating the first layer of thin film resistor network and the second position point penetrating the second layer of thin film resistor network, the moving speed and moving direction of the projectile between the two layers of thin film resistor network are obtained.

10. The parameter testing method based on the resistance film according to claim 9, characterized in that: Determine the projectile velocity and projectile direction, including: Acquire a damaged image of the first layer of thin film resistor network, and perform burr analysis on the damaged image to determine the impact energy of the projectile on the first layer of thin film resistor network; The projectile launch starting point, the first position point of penetrating the first layer of thin film resistor network, and the second position point of penetrating the second layer of thin film resistor network are reflected in a preset coordinate system to determine the projectile's initial speed, initial direction, and direction linkage line; The impact damage of the damaged image is reflected in a preset coordinate system, and 1° cuts are made along the direction of movement according to the intersection points of the directional linkage lines, and the energy attenuation factor at each 1° angle is obtained in combination with the impact energy; Inferring a reference velocity at which the projectile hits the first thin film resistor layer based on the energy attenuation factor; The initial speed is verified according to the reference speed.

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