A method and system for impact location of a composite material flat plate structure

Abstract

The present invention provides a method for impact location of a composite material flat plate structure, which includes obtaining in real time signals transmitted by six piezoelectric sensors in two sensor arrays arranged on the composite material flat plate structure; wherein, three piezoelectric sensors in one sensor array form an isosceles right triangle, and three piezoelectric sensors in the other sensor array are arranged symmetrically with respect to the central axis of the plate plane; determining the moment when the signals transmitted by the six piezoelectric sensors simultaneously meet the predetermined conditions to record the time when each piezoelectric sensor receives the shock wave signal; based on the time when each piezoelectric sensor receives the shock wave signal and in combination with the geometric position relationship between the two sensor arrays, calculating two incoming wave directions of the impact point to further obtain the impact point position. Implementing the present invention can effectively solve the problems of the traditional location technology, such as the need for a large number of sensors for impact location of a composite material flat plate structure, dependence on wave speed information that is difficult to obtain, and poor practicability.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material structure health monitoring, and particularly to a method and system for impact location of a composite material flat plate structure. Background Art

[0002] Composite materials have many advantages over traditional materials, such as high specific strength, high specific modulus, high temperature resistance, corrosion resistance, fatigue resistance, good damping and shock absorption properties, good damage safety, and designable properties. As a result, composite material structures are increasingly widely used in various engineering structures. Due to the inhomogeneity and anisotropy of composite materials, their damage forms are very different from those of isotropic metal materials. For example, when a composite material structure is subjected to an external impact, there is almost no visible damage on the surface of the structure, but serious damage may have occurred inside (such as interlayer delamination, fiber fracture, etc.). Therefore, monitoring whether the structure is impacted is one of the important contents of composite material structure health monitoring. Further, locating the monitored impact can provide great convenience for targeted damage detection of composite material structures.

[0003] Detecting the impact position of a structure through sound source localization technology is a common method for structure impact location. However, this traditional sound source localization technology often requires a large number of sensors, resulting in a complex positioning system and low reliability. For example, the sound source localization technology based on beamforming estimates the direction of the incoming wave through the constructive interference of different sensor signals. Therefore, a large number of sensors are often required to ensure the positioning accuracy. In addition, the beamforming technology must know the wave velocities in all directions of the measured structure to estimate the direction of the incoming wave. However, due to the influence of various complex factors such as fiber direction and matrix material, it is often difficult to obtain accurate wave velocity information for anisotropic composite material structures.

[0004] Therefore, there is an urgent need for a brand-new method for impact location of a composite material flat plate structure to solve the problems of the traditional positioning technology, such as a large number of sensors required for impact location of a composite material flat plate structure, dependence on difficult-to-obtain wave velocity information, and poor practicability. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide a method and system for impact location of a composite material flat plate structure, which can effectively solve the problems of the traditional positioning technology, such as a large number of sensors required for impact location of a composite material flat plate structure, dependence on difficult-to-obtain wave velocity information, and poor practicability.

[0006] To solve the above technical problem, the embodiments of the present invention provide a method for impact location of a composite material flat plate structure, and the method includes the following steps:

[0007] Obtain in real time the signals transmitted by six piezoelectric sensors in two sensor arrays provided on the composite material flat structure; among them, three piezoelectric sensors in one sensor array are installed in a right-angled isosceles triangle at one corner of the composite material flat structure, and three piezoelectric sensors in the other sensor array are symmetrically arranged in a corresponding right-angled isosceles triangle at the other corner of the composite material flat structure with the central axis of the plate plane as the axis of symmetry;

[0008] According to the signals transmitted by the six piezoelectric sensors obtained in real time, determine the moment when the signals transmitted by the six piezoelectric sensors simultaneously meet the predetermined conditions, and starting from the determined moment, record the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal backward;

[0009] Based on the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal, and combined with the geometric position relationship of each piezoelectric sensor in the two sensor arrays between the corresponding right-angled isosceles triangles, calculate the incoming wave directions of the impact point relative to the two sensor arrays respectively, so as to further obtain the impact point position.

[0010] Among them, the predetermined condition is that the absolute value of the signal transmitted by any piezoelectric sensor is equal to the preset threshold.

[0011] Among them, the time when each piezoelectric sensor receives the shock wave signal is the moment when the first wave peak arrives in the corresponding waveform.

[0012] Among them, the specific steps of calculating the incoming wave directions of the impact point relative to the two sensor arrays respectively based on the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal, and combined with the geometric position relationship of each piezoelectric sensor in the two sensor arrays between the corresponding right-angled isosceles triangles, and further obtaining the position of the impact point include:

[0013] Obtain the geometric position relationship of each piezoelectric sensor in the two sensor arrays between the corresponding right-angled isosceles triangles; among them, the two sensor arrays include sensor array A1 and sensor array A2; the geometric position relationship of sensor array A1 is that piezoelectric sensor S1 is located at the right-angled point of the right-angled isosceles triangle, and it forms the horizontal right-angled side of the right-angled isosceles triangle with piezoelectric sensor S2, and it forms the vertical right-angled side of the right-angled isosceles triangle with piezoelectric sensor S3; the geometric position relationship of sensor array A2 is that piezoelectric sensor S4 is located at the right-angled point of the right-angled isosceles triangle, and it forms the horizontal right-angled side of the right-angled isosceles triangle with piezoelectric sensor S5, and it forms the vertical right-angled side of the right-angled isosceles triangle with piezoelectric sensor S6;

[0014] In the sensor array A1, the time when the piezoelectric sensor S2 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S1 receives the shock wave signal to obtain a first time difference, and the time when the piezoelectric sensor S3 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S1 receives the shock wave signal to obtain a second time difference. And through the formula the incoming wave direction θ1 of the impact point relative to the sensor array A1 is obtained; where, Δt 12 is the first time difference; Δt 13 is the second time difference;

[0015] In the sensor array A2, the time when the piezoelectric sensor S5 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S4 receives the shock wave signal to obtain a third time difference, and the time when the piezoelectric sensor S6 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S4 receives the shock wave signal to obtain a fourth time difference. And through the formula the incoming wave direction θ2 of the impact point relative to the sensor array A2 is obtained; where, Δt 45 is the third time difference; Δt 46 is the fourth time difference;

[0016] Based on the right-angle point of the piezoelectric sensor S1 in the sensor array A1 as the starting point and the incoming wave direction θ1 of the impact point relative to the sensor array A1 as the horizontal azimuth angle, a ray is drawn. And based on the right-angle point of the piezoelectric sensor S4 in the sensor array A2 as the starting point and the incoming wave direction θ2 of the impact point relative to the sensor array A2 as the horizontal azimuth angle, another ray is drawn. And further, the intersection point of the two rays is determined as the impact point position.

[0017] Among them, the six piezoelectric sensors in the two sensor arrays have the same structure, and are all made of circular lead zirconate titanate piezoelectric ceramic sheets and are pasted on the composite material flat plate structure through quick-drying strong glue; where, the diameters of the six piezoelectric sensors are all 2-5 times the thickness of the composite material flat plate structure.

[0018] Among them, the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are respectively parallel to the adjacent two sides of the composite material flat plate structure, and the lengths of the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are 2-3 times the diameter of the piezoelectric sensor.

[0019] The embodiment of the present invention also provides a composite material flat plate structure impact positioning system, including:

[0020] A signal acquisition unit, configured to acquire in real time signals transmitted by six piezoelectric sensors in two sensor arrays arranged on a composite material flat plate structure; wherein, three piezoelectric sensors in one sensor array are installed at a corner of the composite material flat plate structure in an isosceles right triangle, and three piezoelectric sensors in the other sensor array are symmetrically arranged at another corner of the composite material flat plate structure in a corresponding isosceles right triangle with the central axis of the plate plane as the axis of symmetry;

[0021] An impact moment identification unit, configured to determine, according to the signals transmitted by the six piezoelectric sensors acquired in real time, the moment when the signals transmitted by the six piezoelectric sensors simultaneously meet a predetermined condition, and starting from the determined moment, record backward the time when each piezoelectric sensor in the two sensor arrays receives a shock wave signal;

[0022] An impact point positioning unit, configured to calculate the incident wave directions of the impact point relative to the two sensor arrays respectively based on the time when each piezoelectric sensor in the two sensor arrays receives a shock wave signal and in combination with the geometric position relationship between each piezoelectric sensor in the two sensor arrays in the corresponding isosceles right triangles, so as to further obtain the impact point position.

[0023] Wherein, the impact point positioning unit includes:

[0024] A position relationship determination module, configured to acquire the geometric position relationship between each piezoelectric sensor in the two sensor arrays in the corresponding isosceles right triangles; wherein, the two sensor arrays include a sensor array A1 and a sensor array A2; the geometric position relationship of the sensor array A1 is that the piezoelectric sensor S1 is located at the right angle point of the isosceles right triangle, and it forms the horizontal right angle side of the isosceles right triangle with the piezoelectric sensor S2, and it forms the vertical right angle side of the isosceles right triangle with the piezoelectric sensor S3; the geometric position relationship of the sensor array A2 is that the piezoelectric sensor S4 is located at the right angle point of the isosceles right triangle, and it forms the horizontal right angle side of the isosceles right triangle with the piezoelectric sensor S5, and it forms the vertical right angle side of the isosceles right triangle with the piezoelectric sensor S6;

[0025] A first incident wave direction calculation module, configured to, in the sensor array A1, subtract the time when the piezoelectric sensor S2 receives a shock wave signal from the time when the piezoelectric sensor S1 receives a shock wave signal to obtain a first time difference, and subtract the time when the piezoelectric sensor S3 receives a shock wave signal from the time when the piezoelectric sensor S1 receives a shock wave signal to obtain a second time difference, and through the formula obtain the incident wave direction θ1 of the impact point relative to the sensor array A1; wherein, Δt 12 is the first time difference; Δt 13 is the second time difference;

[0026] The incoming wave direction second calculation module is configured to subtract the time when the piezoelectric sensor S5 receives the shock wave signal from the time when the piezoelectric sensor S4 receives the shock wave signal in the sensor array A2 to obtain a third time difference, and subtract the time when the piezoelectric sensor S6 receives the shock wave signal from the time when the piezoelectric sensor S4 receives the shock wave signal to obtain a fourth time difference, and obtain the incoming wave direction θ2 of the impact point relative to the sensor array A2 through the formula ; where, Δt 45 is the third time difference; Δt 46 is the fourth time difference;

[0027] The impact point position positioning module is configured to draw a ray starting from the right-angle point of the piezoelectric sensor S1 in the sensor array A1 and with the incoming wave direction θ1 of the impact point relative to the sensor array A1 as the horizontal azimuth angle, and draw another ray starting from the right-angle point of the piezoelectric sensor S4 in the sensor array A2 and with the incoming wave direction θ2 of the impact point relative to the sensor array A2 as the horizontal azimuth angle, and further find the intersection point of the two rays and determine it as the impact point position.

[0028] Among them, the six piezoelectric sensors in the two sensor arrays have the same structure, are all made of circular lead zirconate titanate piezoelectric ceramic sheets, and are pasted on the composite material flat plate structure through fast-drying strong glue; among them, the diameters of the six piezoelectric sensors are all 2-5 times the thickness of the composite material flat plate structure.

[0029] Among them, the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are respectively parallel to the adjacent sides of the composite material flat plate structure, and the lengths of the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are 2-3 times the diameter of the piezoelectric sensor.

[0030] Implementing the embodiments of the present invention has the following beneficial effects:

[0031] In the present invention, two triangular piezoelectric sensor arrays are installed at two corners at one end of a composite material flat plate structure. By continuously monitoring whether the signals of each piezoelectric sensor meet a predetermined condition (such as whether the absolute value of the signal reaches a preset threshold), it is determined whether the composite material flat plate structure is impacted by an external object. Using the time difference of the shock wave signals received by each piezoelectric sensor in the sensor array and combining the geometric position relationship between the sensor arrays, the angle of the impact point relative to the two sensor arrays is calculated, and then the impact position is determined. This can not only reduce the number of sensors, lower the complexity and cost of the monitoring system, but also qualitatively monitor the composite material flat plate structure and quickly locate the impact position when an external object impacts, narrowing the key detection range of composite material damage, greatly improving the efficiency of subsequent damage detection work. At the same time, the impact point can be accurately located without prior knowledge such as the material parameters of the composite material structure to be measured and the wave velocities in different directions, which has high practicability. Therefore, it can effectively solve the problems of the traditional positioning technology, such as the need for a large number of sensors for impact positioning of the composite material flat plate structure, dependence on the wave velocity information that is difficult to obtain, and low practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present invention.

[0033] Figure 1 It is a flowchart of a method for impact positioning of a composite material flat plate structure provided by an embodiment of the present invention;

[0034] Figure 2 It is a schematic diagram of a calculation device connected to six piezoelectric sensors in two sensor arrays provided on a composite material flat plate structure through a data acquisition instrument in a method for impact positioning of a composite material flat plate structure provided by an embodiment of the present invention;

[0035] Figure 3 It is a comparison diagram of the times when six piezoelectric sensors S1 to S6 receive shock wave signals in an application scenario of a method for impact positioning of a composite material flat plate structure provided by an embodiment of the present invention;

[0036] Figure 4 It is a schematic diagram of impact point positioning in an application scenario of a method for impact positioning of a composite material flat plate structure provided by an embodiment of the present invention;

[0037] Figure 5 It is a schematic diagram of the structure of a system for impact positioning of a composite material flat plate structure provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] As Figure 1 shown, in an embodiment of the present invention, a method for impact location of a composite material flat plate structure is proposed, which is implemented on a computing device (such as Figure 2 shown) that is connected to six piezoelectric sensors in two sensor arrays provided on the composite material flat plate structure through a data acquisition instrument. The method includes the following steps:

[0040] Step S1: Real-time obtain the signals transmitted by six piezoelectric sensors in two sensor arrays provided on the composite material flat plate structure; wherein, three piezoelectric sensors in one sensor array are installed in a right-angled isosceles triangle at one corner of the composite material flat plate structure, and three piezoelectric sensors in the other sensor array are symmetrically arranged in a corresponding right-angled isosceles triangle at the other corner of the composite material flat plate structure with the central axis of the plate plane as the axis of symmetry;

[0041] Step S2: According to the signals transmitted by the six piezoelectric sensors obtained in real time, determine the moment when the signals transmitted by the six piezoelectric sensors simultaneously meet the predetermined conditions, and starting from the determined moment, record the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal backward;

[0042] Step S3: Based on the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal, and in combination with the geometric position relationship of each piezoelectric sensor in the two sensor arrays between the corresponding right-angled isosceles triangles, calculate the incoming wave directions of the impact point relative to the two sensor arrays respectively, so as to further obtain the impact point position.

[0043] Specifically, before step S1, on the composite material flat plate structure, there are sensor array A1 and sensor array A2; wherein, the six piezoelectric sensors S1 to S6 in sensor array A1 and sensor array A2 have the same structure, and are all made of circular lead zirconate titanate piezoelectric ceramic sheets, and are pasted on the composite material flat plate structure through quick-drying strong glue. The diameters of these six piezoelectric sensors S1 to S6 are 2 to 5 times the thickness of the composite material flat plate structure, and further, these six piezoelectric sensors S1 to S6 are sequentially connected to six input channels of a data acquisition instrument and then connected to a computing device. At this time, three piezoelectric sensors S1 to S3 in sensor array A1 are installed in a right-angled isosceles triangle at one corner of the composite material flat plate structure (such as Figure 2(at the lower left corner), three piezoelectric sensors S4 to S6 in the sensor array A2 are symmetrically arranged in an isosceles right triangle at the other corner of the composite material flat structure with the central axis of the plate plane as the axis of symmetry (such as Figure 2 (at the upper left corner). The two right-angled sides of these two isosceles right triangles are respectively parallel to the adjacent sides of the composite material flat structure, and the lengths of the two right-angled sides of these two isosceles right triangles are 2 to 3 times the diameter of the piezoelectric sensors S1 to S6.

[0044] In one example, the piezoelectric sensor S1 is located at the right-angled point of the isosceles right triangle in the sensor array A1. It forms the horizontal right-angled side of the isosceles right triangle in the sensor array A1 with the piezoelectric sensor S2, and it forms the vertical right-angled side of the isosceles right triangle in the sensor array A1 with the piezoelectric sensor S3; the piezoelectric sensor S4 is located at the right-angled point of the isosceles right triangle in the sensor array A2, and it forms the horizontal right-angled side of the isosceles right triangle in the sensor array A2 with the piezoelectric sensor S5, and it forms the vertical right-angled side of the isosceles right triangle in the sensor array A2 with the piezoelectric sensor S6.

[0045] In step S1, the data acquisition instrument continuously acquires the voltage analog signals output by these six piezoelectric sensors S1 to S6, converts the analog signals into digital signals at a sampling frequency of 1 MHz, filters the initial signals with a band-pass filter, and sends the filtered signals to the computing device so that the computing device can obtain the signals transmitted by these six piezoelectric sensors S1 to S6 in real time.

[0046] In step S2, continuously monitor whether the output signals of these six piezoelectric sensors S1 to S6 after filtering meet the preset conditions; among them, the preset condition is that the absolute value of the signal transmitted by any piezoelectric sensor is equal to the preset threshold.

[0047] If the absolute values of the signals are all less than the preset threshold, it means that the composite material flat structure has not been impacted, and continue to monitor; if the absolute values of the signals all reach the preset threshold, it means that the composite material flat structure has been impacted, start impact positioning, and determine the moment when all reach the preset threshold.

[0048] Starting from the moment value when it is determined that all reach the preset threshold, start searching backward for the time when these six piezoelectric sensors S1 to S6 receive the shock wave signal. For example, record the initial extreme points and their moments t1, t2, t3, t4, t5, t6, that is, the moments when the first wave peaks in the signal waveform arrive, as Figure 3 shown. Figure 3Among them, the upper figure shows the voltage signals included in the sensor array A1, and the lower figure shows the voltage signals included in the sensor array A2. The amplitude of the front segment of the signal is almost zero, and obvious fluctuations appear in the rear segment and the absolute value exceeds the preset threshold, indicating that the shock wave conduction to the piezoelectric sensor causes an increase in the output voltage of the piezoelectric sensor (piezoelectric effect).

[0049] In step S3, first, obtain the geometric position relationship of each piezoelectric sensor in the two sensor arrays between the corresponding isosceles right triangles; among them, the two sensor arrays include the sensor array A1 and the sensor array A2; the geometric position relationship of the sensor array A1 is that the piezoelectric sensor S1 is located at the right-angled point of the isosceles right triangle, and it forms the horizontal right-angled side of the isosceles right triangle with the piezoelectric sensor S2, and it forms the vertical right-angled side of the isosceles right triangle with the piezoelectric sensor S3; the geometric position relationship of the sensor array A2 is that the piezoelectric sensor S4 is located at the right-angled point of the isosceles right triangle, and it forms the horizontal right-angled side of the isosceles right triangle with the piezoelectric sensor S5, and it forms the vertical right-angled side of the isosceles right triangle with the piezoelectric sensor S6;

[0050] Secondly, in the sensor array A1, subtract the time when the piezoelectric sensor S2 receives the shock wave signal from the time when the piezoelectric sensor S1 receives the shock wave signal to obtain the first time difference Δt 12 and subtract the time when the piezoelectric sensor S3 receives the shock wave signal from the time when the piezoelectric sensor S1 receives the shock wave signal to obtain the second time difference Δt 13 and obtain the incoming wave direction θ1 of the impact point relative to the sensor array A1 through the formula ;

[0051] Then, in the sensor array A2, subtract the time when the piezoelectric sensor S5 receives the shock wave signal from the time when the piezoelectric sensor S4 receives the shock wave signal to obtain the third time difference Δt 45 and subtract the time when the piezoelectric sensor S6 receives the shock wave signal from the time when the piezoelectric sensor S4 receives the shock wave signal to obtain the fourth time difference Δt 46 and obtain the incoming wave direction θ2 of the impact point relative to the sensor array A2 through the formula ;

[0052] Finally, based on the right-angled point of the piezoelectric sensor S1 in the sensor array A1 as the starting point and the incoming wave direction θ1 of the impact point relative to the sensor array A1 as the horizontal azimuth angle, draw a ray, and based on the right-angled point of the piezoelectric sensor S4 in the sensor array A2 as the starting point and the incoming wave direction θ2 of the impact point relative to the sensor array A2 as the horizontal azimuth angle, draw another ray, and further find the intersection point of the two rays and determine it as the impact point position, as Figure 4 shown. Figure 4In it, two rays are drawn from the sensor arrays A1 and A2 at the included angles θ1 and θ2, and the intersection point of the two straight lines is the estimated position of the impact point.

[0053] In one example, the experimental parameters are as follows: the composite material flat plate structure size is 900x900x2.5 mm, the diameter of the piezoelectric sensor is 10 mm, the thickness of the piezoelectric sensor is 1 mm, and the length of the right-angled side of the isosceles right-angled triangle piezoelectric sensor array is 30 mm. From the formulas and it can be calculated that the incident wave direction angle of the shock wave received by the sensor array A1 is 53.4°, and the incident wave direction angle of the shock wave received by the sensor array A2 is 55.3°; the position of the intersection point obtained by drawing two rays with the right-angled vertices of the two sensor arrays A1 and A2 as endpoints only differs by 9 mm from the actual impact position, indicating that the impact positioning method of the present invention has good accuracy and is worthy of popularization and application.

[0054] As Figure 5 shown, in the embodiment of the present invention, a composite material flat plate structure impact positioning system is provided, including:

[0055] A signal acquisition unit 110, configured to acquire in real time the signals transmitted by the six piezoelectric sensors in the two sensor arrays provided on the composite material flat plate structure; wherein, three piezoelectric sensors in one sensor array are installed in an isosceles right-angled triangle at one corner of the composite material flat plate structure, and three piezoelectric sensors in the other sensor array are symmetrically arranged in an isosceles right-angled triangle at the other corner of the composite material flat plate structure with the central axis of the plate plane as the axis of symmetry.

[0056] An impact time identification unit 120, configured to determine, according to the signals transmitted by the six piezoelectric sensors acquired in real time, the moment when the signals transmitted by the six piezoelectric sensors simultaneously meet the predetermined conditions, and starting from the determined moment, record backward the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal.

[0057] An impact point positioning unit 130, configured to calculate the incident wave directions of the impact point relative to the two sensor arrays based on the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal, and in combination with the geometric position relationship of each piezoelectric sensor in the corresponding isosceles right-angled triangles in the two sensor arrays, so as to further obtain the impact point position.

[0058] Wherein, the impact point positioning unit 130 includes:

[0059] A position relationship determination module, configured to obtain the geometric position relationships of the piezoelectric sensors in the two sensor arrays among the corresponding isosceles right triangles; wherein, the two sensor arrays include a sensor array A1 and a sensor array A2; the geometric position relationship of the sensor array A1 is that the piezoelectric sensor S1 is located at the right-angle point of the isosceles right triangle, and it forms the horizontal right-angle side of the isosceles right triangle with the piezoelectric sensor S2, and it forms the vertical right-angle side of the isosceles right triangle with the piezoelectric sensor S3; the geometric position relationship of the sensor array A2 is that the piezoelectric sensor S4 is located at the right-angle point of the isosceles right triangle, and it forms the horizontal right-angle side of the isosceles right triangle with the piezoelectric sensor S5, and it forms the vertical right-angle side of the isosceles right triangle with the piezoelectric sensor S6;

[0060] A first incoming wave direction calculation module, configured to, in the sensor array A1, subtract the time when the piezoelectric sensor S2 receives the shock wave signal from the time when the piezoelectric sensor S1 receives the shock wave signal to obtain a first time difference, and subtract the time when the piezoelectric sensor S3 receives the shock wave signal from the time when the piezoelectric sensor S1 receives the shock wave signal to obtain a second time difference, and obtain the incoming wave direction θ1 of the impact point relative to the sensor array A1 through the formula where Δt 12 is the first time difference; Δt 13 is the second time difference;

[0061] A second incoming wave direction calculation module, configured to, in the sensor array A2, subtract the time when the piezoelectric sensor S5 receives the shock wave signal from the time when the piezoelectric sensor S4 receives the shock wave signal to obtain a third time difference, and subtract the time when the piezoelectric sensor S6 receives the shock wave signal from the time when the piezoelectric sensor S4 receives the shock wave signal to obtain a fourth time difference, and obtain the incoming wave direction θ2 of the impact point relative to the sensor array A2 through the formula where Δt 45 is the third time difference; Δt 46 is the fourth time difference;

[0062] An impact point position positioning module, configured to draw a ray starting from the right-angle point of the piezoelectric sensor S1 in the sensor array A1 and with the incoming wave direction θ1 of the impact point relative to the sensor array A1 as the horizontal azimuth angle, and draw another ray starting from the right-angle point of the piezoelectric sensor S4 in the sensor array A2 and with the incoming wave direction θ2 of the impact point relative to the sensor array A2 as the horizontal azimuth angle, and further find the intersection point of the two rays and determine it as the impact point position.

[0063] Among them, the structures of the six piezoelectric sensors in the two sensor arrays are the same. They are all made of circular lead zirconate titanate piezoelectric ceramic sheets and are pasted on the composite material flat plate structure with quick-drying strong glue. Among them, the diameters of the six piezoelectric sensors are 2-5 times the thickness of the composite material flat plate structure.

[0064] Among them, the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are respectively parallel to the adjacent two sides of the composite material flat plate structure, and the lengths of the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are 2-3 times the diameter of the piezoelectric sensor.

[0065] Implementing the embodiments of the present invention has the following beneficial effects:

[0066] In the present invention, two triangular piezoelectric sensor arrays are installed at two corners at one end of the composite material flat plate structure. By continuously monitoring whether the signals of each piezoelectric sensor meet the predetermined conditions (such as whether the absolute value of the signal reaches the preset threshold), it is determined whether the composite material flat plate structure is impacted by an external object. And by using the time difference of the shock wave signals received by each piezoelectric sensor in the sensor array and combining the geometric position relationship between the sensor arrays, the included angle of the impact point relative to the two sensor arrays is calculated, and then the impact position is determined. This can not only reduce the number of sensors, lower the complexity and cost of the monitoring system, but also qualitatively monitor the composite material flat plate structure and quickly locate the impact position when an external object impacts, narrow the key detection range of composite material damage, greatly improve the efficiency of subsequent damage detection work, and at the same time accurately locate the impact point without prior knowledge such as the material parameters of the measured composite material structure and the wave velocities in different directions, which has high practicability. Therefore, it can effectively solve the problems of the traditional positioning technology that requires a large number of sensors for impact positioning of the composite material flat plate structure, relies on wave velocity information that is difficult to obtain, and has poor practicability.

[0067] It should be noted that in the above system embodiments, the included units are only divided according to functional logic, but are not limited to the above division as long as the corresponding functions can be achieved. In addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0068] Those of ordinary skill in the art can understand that all or part of the steps in implementing the above method embodiments can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, optical disc, etc.

[0069] The above-disclosed is only a preferred embodiment of the present invention. Of course, it cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A method for impact location of a composite material flat plate structure, characterized in that, The method includes the following steps: Obtain in real time the signals transmitted by six piezoelectric sensors in two sensor arrays arranged on the composite material flat plate structure; wherein, three piezoelectric sensors in one sensor array are installed at a corner of the composite material flat plate structure in an isosceles right triangle, and three piezoelectric sensors in the other sensor array are symmetrically arranged in an isosceles right triangle at the other corner of the composite material flat plate structure with the central axis of the plate plane as the axis of symmetry; According to the signals transmitted by the six piezoelectric sensors obtained in real time, determine the moment when the signals transmitted by the six piezoelectric sensors simultaneously meet the predetermined conditions, and starting from the determined moment, record backward the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal; Based on the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal, and combined with the geometric position relationship between each piezoelectric sensor in the two sensor arrays in the corresponding isosceles right triangles, calculate the incoming wave directions of the impact point relative to the two sensor arrays respectively, so as to further obtain the impact point position; The specific steps of calculating the incoming wave directions of the impact point relative to the two sensor arrays respectively based on the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal and combined with the geometric position relationship between each piezoelectric sensor in the two sensor arrays in the corresponding isosceles right triangles, and further obtaining the position of the impact point include: Obtain the geometric position relationship between each piezoelectric sensor in the two sensor arrays among the corresponding isosceles right triangles; among them, the two sensor arrays include sensor array A 1 and sensor array A 2 ; The geometric position relationship of the sensor array A 1 is that the piezoelectric sensor S 1 is located at the right-angle point of the isosceles right triangle, and it forms the horizontal right-angle side of the isosceles right triangle with the piezoelectric sensor S 2 , and it forms the vertical right-angle side of the isosceles right triangle with the piezoelectric sensor S 3 ; The geometric position relationship of the sensor array A 2 is that the piezoelectric sensor S 4 is located at the right-angle point of the isosceles right triangle, and it forms the horizontal right-angle side of the isosceles right triangle with the piezoelectric sensor S 5 , and it forms the vertical right-angle side of the isosceles right triangle with the piezoelectric sensor S 6 ; In the sensor array A 1 the time when the piezoelectric sensor S 2 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S 1 receives the shock wave signal to obtain a first time difference, and the time when the piezoelectric sensor S 3 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S 1 receives the shock wave signal to obtain a second time difference, and through the formula the arrival direction of the impact point relative to the sensor array A 1 is obtained ; where is the first time difference; is the second time difference; In the sensor array A 2 the time when the piezoelectric sensor S 5 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S 4 receives the shock wave signal to obtain a third time difference, and the time when the piezoelectric sensor S 6 receives the shock wave signal is subtracted from the time when the piezoelectric sensor S 4 receives the shock wave signal to obtain a fourth time difference, and through the formula the arrival direction of the impact point relative to the sensor array A 2 is obtained ; where is the third time difference; is the fourth time difference; Based on the sensor array A 1 the piezoelectric sensor in S 1 Taking the right-angle point of the piezoelectric sensor as the starting point and the impact point relative to the sensor array A 1 the incoming wave direction as the horizontal azimuth angle, draw a ray, and based on the sensor array A 2 the piezoelectric sensor in S 4 Taking the right-angle point of the piezoelectric sensor as the starting point and the impact point relative to the sensor array A 2 the incoming wave direction as the horizontal azimuth angle, draw another ray, and further find the intersection point of the two rays to determine the impact point position.

2. The method for impact location of the composite material flat plate structure according to claim 1, characterized in that The predetermined condition is that the absolute value of the signal transmitted by any piezoelectric sensor is equal to the preset threshold.

3. The method for impact location of the composite material flat plate structure according to claim 1, characterized in that, The time when each piezoelectric sensor receives the shock wave signal is the moment when the first wave peak arrives in the corresponding waveform.

4. The method for impact location of the composite material flat plate structure according to claim 1, wherein, The six piezoelectric sensors in the two sensor arrays have the same structure, are all made of circular lead zirconate titanate piezoelectric ceramic sheets, and are pasted on the composite material flat plate structure with fast-drying strong glue; wherein, the diameters of the six piezoelectric sensors are 2-5 times the thickness of the composite material flat plate structure.

5. The method for impact location of the composite material flat plate structure according to claim 4, characterized in that, The two right-angled sides of the isosceles right triangle formed by the two sensor arrays are respectively parallel to the adjacent sides of the composite material flat plate structure, and the lengths of the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are 2-3 times the diameter of the piezoelectric sensor.

6. An impact location system for a composite material flat plate structure, characterized in that, Include: A signal acquisition unit, configured to obtain in real time the signals transmitted by six piezoelectric sensors in two sensor arrays arranged on the composite material flat plate structure; wherein, three piezoelectric sensors in one sensor array are installed at a corner of the composite material flat plate structure in an isosceles right triangle, and three piezoelectric sensors in the other sensor array are symmetrically arranged in an isosceles right triangle at the other corner of the composite material flat plate structure with the central axis of the plate plane as the axis of symmetry; An impact moment identification unit, configured to determine the moment when the signals transmitted by the six piezoelectric sensors simultaneously meet the predetermined conditions according to the signals transmitted by the six piezoelectric sensors obtained in real time, and starting from the determined moment, record backward the time when each piezoelectric sensor in the two sensor arrays receives the shock wave signal; An impact point positioning unit, which is used to calculate the incident directions of the impact point relative to the two sensor arrays respectively based on the time when the piezoelectric sensors in the two sensor arrays receive the shock wave signals, and in combination with the geometric position relationship of the piezoelectric sensors in the two sensor arrays among the corresponding isosceles right triangles, so as to further obtain the impact point position; The impact point positioning unit includes: A position relationship determination module, configured to obtain the geometric position relationships of the piezoelectric sensors in the two sensor arrays among the corresponding isosceles right triangles; wherein, the two sensor arrays include sensor array A 1 and sensor array A 2 ; the geometric position relationship of the sensor array A 1 is that the piezoelectric sensor S 1 is located at the right-angle point of the isosceles right triangle, and it forms the horizontal right-angle side of the isosceles right triangle with the piezoelectric sensor S 2 , and it forms the vertical right-angle side of the isosceles right triangle with the piezoelectric sensor S 3 ; the geometric position relationship of the sensor array A 2 is that the piezoelectric sensor S 4 is located at the right-angle point of the isosceles right triangle, and it forms the horizontal right-angle side of the isosceles right triangle with the piezoelectric sensor S 5 , and it forms the vertical right-angle side of the isosceles right triangle with the piezoelectric sensor S 6 ; The first arrival direction calculation module is used to, in the sensor array A 1 , subtract the time when the piezoelectric sensor S 2 receives the shock wave signal from the time when the piezoelectric sensor S 1 receives the shock wave signal to obtain a first time difference, and subtract the time when the piezoelectric sensor S 3 receives the shock wave signal from the time when the piezoelectric sensor S 1 receives the shock wave signal to obtain a second time difference, and obtain the arrival direction of the impact point relative to the sensor array through the formula A 1 ; where ; among them, is the first time difference; is the second time difference; The second incident wave direction calculation module is configured to, in the sensor array A 2 , subtract the time when a piezoelectric sensor receives a shock wave signal from the time when another piezoelectric sensor receives a shock wave signal to obtain a third time difference, and subtract the time when a piezoelectric sensor receives a shock wave signal from the time when another piezoelectric sensor receives a shock wave signal to obtain a fourth time difference, and obtain the incident wave direction of the impact point relative to the sensor array S 5 through the formula S 4 ; where S 6 is the third time difference; S 4 is the fourth time difference; , and obtain the incident wave direction of the impact point relative to the sensor array A 2 ; ; is the third time difference; is the fourth time difference; The impact point location positioning module is used to locate the impact point based on the sensor array. A 1 Piezoelectric Sensors in S 1 The right angle point is the starting point and the impact point relative to the sensor array A 1 The direction of the wave is the horizontal azimuth, a ray is drawn, and based on the sensor array A 2 Piezoelectric Sensors in S 4 The right angle point is the starting point and the impact point relative to the sensor array A 2 The direction of the wave is the horizontal azimuth, another ray is drawn, and the intersection of the two rays is further found to determine the impact point position.

7. The composite flat plate structure impact positioning system according to claim 6, characterized in that, The six piezoelectric sensors in the two sensor arrays have the same structure, and are all made of circular lead zirconate titanate piezoelectric ceramic sheets and are pasted on the composite material flat plate structure through fast-drying strong glue; wherein, the diameters of the six piezoelectric sensors are 2-5 times the thickness of the composite material flat plate structure.

8. The composite flat structure impact location system according to claim 7, wherein The two right-angled sides of the isosceles right triangle formed by the two sensor arrays are respectively parallel to the adjacent two sides of the composite material flat plate structure, and the lengths of the two right-angled sides of the isosceles right triangle formed by the two sensor arrays are 2-3 times the diameter of the piezoelectric sensor.

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