Single-row fluxgate sensor parallel array for observing flight speed of target and method thereof

Abstract

The invention belongs to the technical field of magnetic field detection, and discloses a single-row fluxgate sensor parallel array for observing the flight speed of a target and a method thereof. A flat and straight sliding groove is formed in the mounting rack of the single-row fluxgate sensor parallel array, a plurality of probes are clamped in the sliding groove and vertically face the three-axis fluxgate sensor, and the distance between the probes is adjusted through the sliding groove; according to the observation method, a threshold value of a magnetic induction total field intensity change curve peak value interval of a ferromagnetic target in a point passing area is set, and a peak value interval when the ferromagnetic target is closest to a three-axis fluxgate probe is captured and judged, so that point passing moments of the ferromagnetic target at observation points of three-axis fluxgate sensors are accurately obtained; space-time observation of the ferromagnetic target is achieved, and then the flight speed of the ferromagnetic target in a single-row fluxgate sensor parallel array route is monitored in the whole process. The single-row fluxgate sensor parallel array for observing the flight speed of the target is flexible in structure and simple in observation method, and has engineering practical value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnetic field detection, and particularly relates to a single-column magnetic flux gate sensor parallel array for observing the flight speed of a target and a method thereof. BACKGROUND

[0002] The spatiotemporal observation of high-speed flying targets is one of the main testing methods for free-flight trajectory target tests and atmospheric environment external target range tests, and can also provide key spatiotemporal references and triggering instructions for other testing equipment. At present, spatiotemporal observation mainly adopts optical and radar detection. However, the aerodynamic optical effect and plasma flow field effect generated by the target during high-speed flight will seriously affect the optical and radar detection process, especially the influence on the target capture, trajectory generation and accurate positioning process is more obvious. When phenomena such as self-luminous, refraction, and wake shock occur, the process of measuring the speed of the target using conventional optical detection means such as light curtain detection control instruments and photoelectric detectors becomes unstable, and problems such as false triggering, reduced speed measurement accuracy, and speed measurement failure are prone to occur. Moreover, the plasma sheath generated around the high-speed target will cause the black barrier effect, and the radar scattering characteristics are severely affected by the plasma, so the radar speed measurement process is also strongly disturbed.

[0003] Magnetic detection technology is a passive detection technology, which captures the target by measuring the magnetic field and the change amount of the magnetic field around the ferromagnetic target. The process of realizing target speed measurement by using magnetic detection technology is not affected by plasma and is not affected by fire smoke shielding. The magnetic force line can penetrate any object without ferromagnetic components, realizing the ability of wall detection. The magnetic detection technology can capture the change amount of the magnetic field near the point where the target flies, so as to determine the accurate time when the target approaches, and achieve the target speed measurement process.

[0004] Magnetic sensors include magnetoresistive sensors, proton magnetometers, optical pumping sensors, CPT magnetometers, superconducting quantum interference devices, and magnetic flux gate sensors. Among them, the magnetic flux gate sensor is developed based on the transformer effect, and the bandwidth of the magnetic flux gate sensor is relatively high, and has the advantages of good stability, wide temperature requirement, strong adaptability to complex environment, wide application range, low manufacturing cost, good precision retention, etc. The magnetic gradient tensor system composed of multiple magnetic flux gate sensors has the advantages of low price, good adaptability, simple structure, and stable measurement. At present, the noise of the three-axis magnetic flux gate sensor on the market can reach ≤6pT / Hz 1 / 2 @1Hz, the range can cover ±70μT ~100μT, the bandwidth can reach 10kHz and above, and it can detect and identify the ferromagnetic target moving rapidly in the geomagnetic environment, and even accurately identify the change amount of the weak magnetic field environment of nT or even pT level. It has strong pertinence to the change of magnetic moment or the movement of ferromagnetic targets in a stable surrounding ferromagnetic environment, and is very suitable for observing the ferromagnetic targets performing rapid flight, movement and slight passing actions.

[0005] At present, it is urgent to develop a single column magnetic flux gate sensor parallel array for observing target flight speed and a method thereof. SUMMARY

[0006] One of the technical problems to be solved by the present application is to provide a single column magnetic flux gate sensor parallel array for observing target flight speed, and another technical problem to be solved by the present application is to provide a target flight speed observation method based on the single column magnetic flux gate sensor parallel array, so as to overcome the defects of the prior art.

[0007] The mounting rack of the single column magnetic flux gate sensor parallel array for observing target flight speed is provided with a flat chute, and a plurality of three-axis magnetic flux gate sensors are clamped on the chute; the probes of the three-axis magnetic flux gate sensors are all vertically directed towards the target, and the labels are sequentially sensor 1, sensor 2, sensor 3, …, sensor n, sensor n+1, … from front to back; the spacing between the three-axis magnetic flux gate sensors is adjusted through the chute; The three-axis magnetic flux gate sensors with the same spacing are provided with different spacings according to test requirements; The target flies along a path parallel to the chute from front to back.

[0008] Further, the number of the three-axis magnetic flux gate sensors and the length of the chute are adjusted according to test requirements, the mounting rack is made of non-magnetic material, and the target is a ferromagnetic target.

[0009] Further, the spacing between the three-axis magnetic flux gate sensors is determined according to the shape size, magnetic moment of the target, and the distance between the target and the chute; if the shape size is smaller, the magnetic moment is larger, and the distance is closer, the corresponding three-axis magnetic flux gate sensor total magnetic field strength waveform peak will be steeper, and the observation density is improved by reducing the spacing between the three-axis magnetic flux gate sensors; on the contrary, if the shape size is larger, the magnetic moment is smaller, and the distance is farther, the corresponding three-axis magnetic flux gate sensor total magnetic field strength waveform peak changes more gently, and the speed observation precision is improved by increasing the spacing between the three-axis magnetic flux gate sensors.

[0010] The target flight speed observation method based on the single column magnetic flux gate sensor parallel array comprises the following steps: S10. Calculate the magnetic induction total field strength value of each three-axis magnetic flux gate sensor; Each three-axis magnetic flux gate sensor measures three-axis magnetic induction strength throughout, and the three-axis magnetic induction strength data are used to calculate the magnetic induction total field strength value at the observation point of the corresponding three-axis magnetic flux gate sensor; S20. Calculate the average speed of any travel segment in the parallel array interval; The target is observed in the whole flight trajectory, the magnetic induction total field intensity variation waveform of each three-axis fluxgate sensor is recorded, the identification threshold is set in advance to judge the target reaching time, the continuous observation target position and time information is obtained; the flight speed between each two three-axis fluxgate sensors is calculated, the observation continuous speed of the target at each three-axis fluxgate sensor is obtained; the observation interval speed of the target in any travel segment in the parallel array interval is obtained by combining any two three-axis fluxgate sensors on the parallel array.

[0011] Further, the specific calculation process of S10 is as follows: Let B be the magnetic induction intensity vector measured at the three-axis fluxgate sensor observation point, and the magnetic induction intensity vector is referred to as the magnetic field vector B ; 、 and be the three-axis orthogonal components of the magnetic field vector B , B be the 2-norm of the magnetic field vector B , B be the magnetic induction total field intensity, and the calculation formula is as follows: ; When the distance between the target and the chute, i.e., the observation distance, is more than 2.5 times the size of the target, the target is defined as a magnetic dipole, and the magnetic field vector B of the three-axis fluxgate sensor observation point is related to the observation distance and the magnetic moment as follows: ; wherein μ is the medium permeability, the μ of air, soil or water is μ 0, μ 0=4π×10 -7 N·A -2 ; m is the magnetic moment, ; r is the position vector, , the position vector r is the spatial coordinate vector of the target magnetic moment action point pointing to the corresponding three-axis fluxgate sensor observation point; 、 , indicates the 2-norm of the corresponding vector, and r represents the observation distance, M represents the magnetic moment intensity, M is a scalar; According to the formula, the observation distance r of the target is related to the magnetic induction total field intensity BNegatively correlated with magnetic moment strength M is positively correlated, and the magnetic field vector B It decays with the cubic power of the observation distance.

[0012] Furthermore, the speed calculation formula is as follows: ; in, i =1,2,3,…,n, d is the distance between adjacent three-axis fluxgate sensors, t i For the i A three-axis fluxgate sensor captures the total magnetic field strength B The peak moment, n For spacing d multiples of v i To observe the continuous velocity, v q is the speed of the observation interval.

[0013] Furthermore, the specific setting process of the recognition threshold of S20 is as follows: Perform preliminary measurements to simulate the target passing through the three-axis fluxgate sensor in the test environment according to the actual passing distance, and record the total magnetic induction field strength B Waveform diagram to analyze the total magnetic induction field strength B The waveform diagram is used to obtain the peak interval and threshold interval, and determine the total magnetic induction field strength. B The peak moment in the threshold interval is reached t ; Set the recognition threshold according to the threshold range; for targets with small magnetic moment and long distance, set a lower threshold to capture slight changes in the magnetic field; for situations with large environmental interference, set a higher threshold to filter out weakly magnetic flying targets.

[0014] The single-row fluxgate sensor parallel array for observing target flight speed and the method thereof of the present invention have the following characteristics: a. Utilizes changes in magnetic induction intensity to obtain the flight time and position of ferromagnetic targets and calculate their speed. This approach is unaffected by interference from flashes, obstructions, and plasma sheaths generated by high-speed processes in conventional photoelectric and radar detection. b. The structure of the single-row fluxgate sensor parallel array is flexible and can adapt to different measurement conditions. The spacing of the parallel array can be arbitrarily adjusted to cope with ferromagnetic targets of different sizes, magnetic moment strengths, and distances. c. By pre-measuring the total magnetic field strength threshold, weakly magnetic flying targets and magnetic interference can be filtered out, and the accuracy of judging when ferromagnetic targets pass by can be improved; d. The flying speed between two continuous three-axis fluxgate sensors in the full stroke segment of the parallel array can be observed simultaneously to obtain the observed continuous speed and realize quasi-continuous speed measurement of the ferromagnetic target during flight; or the data of any two three-axis fluxgate sensor combinations can be observed simultaneously to realize average speed measurement of the ferromagnetic target in any stroke segment in the array interval and obtain the observed interval speed; e. The single-column parallel sensor array structure is suitable for the spatial layout of the pot-shaped target chamber and realizes the speed measurement task of tracking the ferromagnetic target throughout the journey.

[0015] The single-column fluxgate sensor parallel array for observing the flying speed of a target and the method thereof are characterized in that the three-axis fluxgate sensor array is arranged in parallel along the direction of flight of the ferromagnetic target in the test environment and the probes are vertically oriented towards the direction of the flight path; the threshold value of the peak interval of the magnetic induction total field intensity change curve of the ferromagnetic target in the passing point area is set; the peak interval when the ferromagnetic target is closest to the three-axis fluxgate probe is captured and judged; the passing time of the ferromagnetic target at each three-axis fluxgate sensor observation point is accurately obtained; the space-time observation of the ferromagnetic target is realized; and the flying speed of the ferromagnetic target in the route of the single-column fluxgate sensor parallel array is monitored throughout the journey.

[0016] The single-column fluxgate sensor parallel array for observing the flying speed of a target and the method thereof can monitor the flying speed of the ferromagnetic ammunition in the ballistic target test; the single-column fluxgate sensor parallel array is arranged directly below the launch target chamber along the ammunition flight path; the distance between the three-axis fluxgate sensors is adjusted to optimize the detection sensitivity of the ferromagnetic ammunition; the single-column fluxgate sensor parallel array observes the speed of the ferromagnetic ammunition in the flight path in real time through synchronous measurement; and the identification threshold value set in advance is used to filter the magnetic interference of other small ferromagnetic fragments and dust.

[0017] The single-column fluxgate sensor parallel array for observing the flying speed of a target and the method thereof can also monitor the satellite launch speed in the spacecraft launch site; the single-column fluxgate sensor parallel array is installed on both sides of the satellite launch platform; a longer three-axis fluxgate sensor spacing is used to cope with the detection target with a long distance and a large magnetic moment; the satellite is observed statically in advance; the process of the satellite passing through the vertical measurement point is simulated through the parallel movement of the three-axis fluxgate sensor; the magnetic field threshold value of the peak interval of the change in the magnetic induction intensity caused by the satellite is measured; and the obtained identification threshold value is used in the actual launch to realize the continuous tracking speed measurement and magnetic interference filtering of the satellite target.

[0018] In short, the single-column fluxgate sensor parallel array structure for observing the flying speed of a target is flexible, the observation method is simple, and compared with the traditional speed measurement methods such as photoelectric detection and radar detection, the single-column fluxgate sensor parallel array structure is not affected by the plasma sheath around the high-speed target and is not affected by the medium blockage such as fire smoke, and has engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a parallel array of single-row fluxgate sensors for observing target flight speed according to the present invention; Figure 2 This is a schematic diagram of the principle of the method for setting the threshold value of the total magnetic induction intensity field value adopted by the present invention.

[0020] In the figure, 1. Three-axis fluxgate sensor; 2. Slide; 3. Mounting stand; 4. Target.

[0021] In the figure, the three-axis fluxgate sensor is simply referred to as sensor; x 、 y 、 z are the coordinate axes of the object coordinate system. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0023] Example 1: Figure 1 As shown, in this embodiment, a mounting frame 3 for a parallel array of single-row fluxgate sensors for observing target flight speed is provided with a straight slide 2, on which a plurality of three-axis fluxgate sensors 1 are mounted. The probes of each three-axis fluxgate sensor 1 are perpendicularly oriented toward the target 4. From front to back, the sensors are numbered as sensor 1, sensor 2, sensor 3, ..., sensor n, sensor n+1, ...; and the spacing between the three-axis fluxgate sensors 1 is adjusted by the slide 2. The three-axis fluxgate sensors 1 have the same spacing, and different spacings are set according to test requirements; The target 4 flies from front to back along a path parallel to the chute 2 .

[0024] Furthermore, the number of the three-axis fluxgate sensors 1 and the length of the slide 2 are adjusted according to the test requirements, the mounting stand 3 is made of non-magnetic material, and the target 4 is a ferromagnetic target.

[0025] Furthermore, the spacing between the three-axis fluxgate sensors 1 is determined based on the external dimensions, magnetic moment, and distance between the target 4 and the slide 2; if the external dimensions are smaller, the magnetic moment is larger, and the distance is closer, the corresponding peak value of the total magnetic field intensity waveform of the three-axis fluxgate sensor 1 will be steeper, and reducing the spacing between the three-axis fluxgate sensors 1 will improve the observation density; conversely, if the external dimensions are larger, the magnetic moment is smaller, and the distance is longer, the corresponding peak value of the total magnetic field intensity waveform of the three-axis fluxgate sensor 1 will change more slowly, and increasing the spacing between the three-axis fluxgate sensors 1 will improve the speed observation accuracy.

[0026] The target flight speed observation method based on a single-row parallel array of fluxgate sensors of this embodiment includes the following steps: S10. Calculate the magnetic induction total field intensity value of each triaxial fluxgate sensor 1; Each triaxial fluxgate sensor 1 measures the triaxial magnetic induction intensity throughout the whole process, and uses the triaxial magnetic induction intensity data to calculate the magnetic induction total field intensity value at the observation point of the corresponding triaxial fluxgate sensor 1; S20. Calculate the average speed of any travel segment within the parallel array interval; The target 4 is observed throughout the flight trajectory, and the magnetic induction total field intensity change waveform of each triaxial fluxgate sensor 1 is recorded. The pre-set identification threshold is used to determine the time when the target 4 arrives at the point, and the continuous observation target position and time information is obtained. The flight speed between any two triaxial fluxgate sensors 1 is calculated, and the observed continuous speed of the target 4 at each triaxial fluxgate sensor 1 is obtained. The observation interval speed of the target 4 in any travel segment within the parallel array interval is obtained by combining any two triaxial fluxgate sensors 1 on the parallel array.

[0027] Further, the specific calculation process of S10 is as follows: Let B be the magnetic induction intensity vector observed at the observation point of the triaxial fluxgate sensor 1, and the magnetic induction intensity vector is simply referred to as the magnetic field vector B ; , and be the three orthogonal components of the magnetic field vector B , B be the 2-norm of the magnetic field vector B , B be the magnetic induction total field intensity, and the calculation formula is as follows: ; When the distance between the target 4 and the chute 2, i.e. the observation distance, exceeds 2.5 times the size of the target 4, the target 4 is defined as a magnetic dipole, and the magnetic field vector B at the observation point of the triaxial fluxgate sensor 1 is related to the observation distance and the magnetic moment as follows: ; Wherein, μ is the medium permeability, and the μ of air, soil or water is μ 0, μ 0=4π×10 -7 N·A -2 ; m is the magnetic moment, ; r is the position vector, , and the position vector ris the spatial coordinate vector of the magnetic moment action point of target 4 pointing to the corresponding observation point of the three-axis fluxgate sensor 1; 、 , represents the 2-norm of the corresponding vector, then r represents the observation distance, M represents the magnetic moment strength, M is a scalar; From formula 2, we can know that the observation distance of target 4 is r Total magnetic field strength B Negatively correlated with magnetic moment strength M is positively correlated, and the magnetic field vector B It decays with the cubic power of the observation distance.

[0028] Furthermore, the speed calculation formula is as follows: ; in, i =1,2,3,…,n, d is the distance between adjacent three-axis fluxgate sensors 1, t i For the i A three-axis fluxgate sensor 1 captures the total magnetic field strength B The peak moment, n For spacing d multiples of v i To observe the continuous velocity, v q is the speed of the observation interval.

[0029] Furthermore, the specific setting process of the recognition threshold of S20 is as follows: In order to effectively filter out the interference of weak magnetic flying targets and accurately determine the arrival time of target 4, the total magnetic induction field strength can be pre-calculated. B The threshold value is set. r With the magnetic field vector B Negatively correlated with magnetic moment strength M If there is a positive correlation, then when the observation distance at the near point is consistent, the total magnetic induction field intensity value is in the same peak range.

[0030] Perform preliminary measurement, simulate the target 4 passing through the three-axis fluxgate sensor 1 according to the actual passing distance in the test environment, and record the obtained Figure 2 The total magnetic field strength shown B Waveform diagram to analyze the total magnetic induction field strength B The waveform diagram is used to obtain the peak interval and threshold interval, and determine the total magnetic induction field strength. B The peak moment in the threshold interval is reachedt According to the threshold interval, the recognition threshold is set; for the target 4 with small magnetic moment and far distance, a lower threshold is set to capture the weak change of the magnetic field; for the case with larger environmental interference, a higher threshold is set to filter the weak magnetic flight target.

[0031] Although the embodiments of the present application have been disclosed as above, it is not limited to the application listed in the specification and the embodiments, and all the features disclosed in the present application, or all the steps in the disclosed method or process, except for the mutually exclusive features and / or steps, can be combined in any manner, without departing from the principles of the present application, and the present application is not limited to specific details and the figures shown and described herein.

Claims

1. A single-row parallel array of fluxgate sensors for observing target flight speed, characterized in that: The mounting stand (3) of the single-row fluxgate sensor parallel array is provided with a straight slide (2), and a plurality of three-axis fluxgate sensors (1) are mounted on the slide (2); the probes of each three-axis fluxgate sensor (1) are vertically oriented toward the target (4), and the numbers from front to back are sensor 1, sensor 2, sensor 3, ..., sensor n, sensor n+1, ...; the spacing between each three-axis fluxgate sensor (1) is adjusted by the slide (2); The three-axis fluxgate sensors (1) have the same spacing, and different spacings are set according to test requirements; The target (4) flies from front to back along a path parallel to the chute (2).

2. The single-row fluxgate sensor parallel array for observing target flight speed according to claim 1, characterized in that: The number of the three-axis fluxgate sensors (1) and the length of the slide slot (2) are adjusted according to the test requirements, the mounting stand (3) is made of non-magnetic material, and the target (4) is a ferromagnetic target.

3. The single-row fluxgate sensor parallel array for observing target flight speed according to claim 1, characterized in that: The spacing between the three-axis fluxgate sensors (1) is determined according to the outer dimensions, magnetic moment, and distance between the target (4) and the slide (2); if the outer dimensions are smaller, the magnetic moment is larger, and the distance is closer, the peak value of the total magnetic field intensity waveform of the corresponding three-axis fluxgate sensor (1) will be steeper, and reducing the spacing between the three-axis fluxgate sensors (1) will improve the observation density; conversely, if the outer dimensions are larger, the magnetic moment is smaller, and the distance is farther, the peak value of the total magnetic field intensity waveform of the corresponding three-axis fluxgate sensor (1) will change more slowly, and increasing the spacing between the three-axis fluxgate sensors (1) will improve the speed observation accuracy.

4. A method for observing target flight speed based on a single-row parallel array of fluxgate sensors, the method being based on the single-row parallel array of fluxgate sensors for observing target flight speed according to any one of claims 1 to 3, characterized in that: The following steps are involved: S10. Calculate the total magnetic field strength value of each three-axis fluxgate sensor (1); Each three-axis fluxgate sensor (1) measures the three-axis magnetic induction intensity throughout the entire process, and uses the three-axis magnetic induction intensity data to calculate the total magnetic induction field intensity value at the corresponding three-axis fluxgate sensor (1) observation point; S20. Calculate the average speed of any segment within the parallel array interval; The target (4) is observed throughout its flight trajectory, and the waveform of the total magnetic induction field intensity change of each three-axis fluxgate sensor (1) is recorded. The arrival time of the target (4) is judged by using a pre-set recognition threshold, and the continuously observed target position and time information is obtained; the flight speed between two adjacent three-axis fluxgate sensors (1) is calculated to obtain the observed continuous speed of the target (4) at each three-axis fluxgate sensor (1); and the observed interval speed of the target (4) in any travel segment within the parallel array interval is obtained by combining any two three-axis fluxgate sensors (1) on the parallel array.

5. The target flight speed observation method based on a single-row fluxgate sensor parallel array according to claim 4, characterized in that: The specific calculation process of S10 is as follows: set up B is the magnetic induction intensity vector measured at the observation point of the three-axis fluxgate sensor (1), and the magnetic induction intensity vector is referred to as the magnetic field vector B ; 、 and is the magnetic field vector B The three-axis orthogonal components of B is the magnetic field vector B The 2-norm of B is the total magnetic induction field strength, and the calculation formula is as follows: ； When the distance between the target (4) and the chute (2), i.e., the observation distance, exceeds 2.5 times the size of the target (4), the target (4) is defined as a magnetic dipole. At this time, the magnetic field vector of the observation point of the three-axis fluxgate sensor (1) is B The relationship between the observation distance and the magnetic moment is: ； in, μ is the magnetic permeability of the medium, air, soil or water μ Take the vacuum permeability μ 0, μ 0=4π×10 -7 N.A. -2 ; m is the magnetic moment, ; r is the position vector, , position vector r is the spatial coordinate vector of the magnetic moment action point of the target (4) pointing to the corresponding observation point of the three-axis fluxgate sensor (1); 、 , represents the 2-norm of the corresponding vector, then r represents the observation distance, M represents the magnetic moment strength, M is a scalar; From formula (2), we can know that the observation distance of target (4) r Total magnetic field strength B Negatively correlated with magnetic moment strength M is positively correlated, and the magnetic field vector B It decays with the cubic power of the observation distance.

6. The target flight speed observation method based on a single-row fluxgate sensor parallel array according to claim 4, characterized in that: The speed calculation formula is as follows: ； in, i =1,2,3,…,n, d is the spacing between adjacent three-axis fluxgate sensors (1), t i For the i A three-axis fluxgate sensor (1) captures the total magnetic field strength B The peak moment, n For spacing d multiples of v i To observe the continuous velocity, v q is the speed of the observation interval.

7. The target flight speed observation method based on a single-row fluxgate sensor parallel array according to claim 4, characterized in that: The specific setting process of the recognition threshold of S20 is as follows: Perform preliminary measurements, simulate the target (4) passing through the three-axis fluxgate sensor (1) in the test environment according to the actual passing distance, and record the total magnetic induction field strength obtained B Waveform diagram to analyze the total magnetic induction field strength B The waveform diagram is used to obtain the peak interval and threshold interval, and determine the total magnetic induction field strength. B The peak moment in the threshold interval is reached t ; Set the recognition threshold according to the threshold range; for targets with small magnetic moments and long distances (4), set a lower threshold to capture slight changes in the magnetic field; for situations with large environmental interference, set a higher threshold to filter out weakly magnetic flying targets.

Images