Single-point multi-azimuth magnetostrictive magnetic field change dynamic prediction device and method of use

Abstract

The application relates to the technical field of magnetic field monitoring, in particular to a single-point multi-azimuth magnetostrictive magnetic field change dynamic prediction device and a use method thereof, which comprises a probe, a probe rod connected with the probe, a magnetostrictive part arranged in the probe rod, a force receiving part arranged in the probe, one end of the magnetostrictive part penetrating into the probe and connected with the force receiving part, and a piezoelectric part arranged in the probe, wherein the piezoelectric part is provided with two groups along the thickness direction of the force receiving part, and the two groups of piezoelectric parts are arranged on the two sides of the force receiving part along the thickness direction of the force receiving part. The application utilizes the principle that the magnetostrictive part will be elongated or shortened when affected by a magnetic field to monitor the magnetic field intensity and direction, and the monitoring precision is relatively high; in addition, the magnetostrictive part is less affected by temperature, is suitable for measurement in relatively harsh environments such as high temperature, and has relatively strong anti-interference capability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic field monitoring, in particular to a single-point multi-direction magnetostrictive magnetic field change dynamic prediction device and use method. BACKGROUND

[0002] With the rapid development of national economy and society, the construction process of engineering projects is gradually becoming automated. Now the country advocates the "smart construction site" detection scheme, aiming to replace the complex and inefficient manual detection through automated equipment monitoring. In order to improve the monitoring efficiency of engineering projects and protect the personal safety of on-site construction personnel. However, most of the current engineering site monitoring equipment uses serial port signal communication. For example, the relatively mature RS485 communication interface uses differential mode to transmit signals, which can reduce electromagnetic interference to a certain extent, but still cannot guarantee sufficient reliability. At this time, it is necessary to judge the electromagnetic interference situation of the equipment installation site, and select a place with relatively low interference for equipment installation through field strength detection equipment to improve the reliability of monitoring.

[0003] Most of the current magnetic field sensors use Hall devices to monitor the magnetic field, but the resolution is not very high. If you want to measure a relatively accurate magnetic field, such as using giant magnetoresistance and other new materials, the cost will be greatly increased. When it is necessary to measure the magnetic field in a relatively harsh environment, such as in a high-temperature environment. The existing magnetic sensor will generate temperature offset due to temperature change. This is a fatal influence on those sites that need accurate measurement. In addition, the existing magnetic field detection equipment itself has weak anti-interference ability to external magnetic fields, and single-line output of signals leads to large noise, so that the measured data cannot present good linearity, affecting the judgment of workers, and bringing great safety hazards.

[0004] In summary, the current magnetic sensor still has non-negligible drawbacks, so there is an urgent need for a new type of monitoring equipment to realize magnetic field monitoring. SUMMARY

[0005] The technical problem to be solved by the present application is: in order to solve the technical problems of low monitoring accuracy, weak anti-interference ability, and great influence of temperature in the prior art, the present application provides a single-point multi-direction magnetostrictive magnetic field change dynamic prediction device and use method, which uses magnetostrictive distance to monitor the magnetic field strength. Not only is it accurate, but it is also strong in anti-interference ability and less affected by temperature. While monitoring the magnetic field strength, it is also convenient to predict the trend of the magnetic field change.

[0006] The single-point multi-azimuth magnetostrictive magnetic field change dynamic prediction device of the present application comprises a probe, a probe rod connected with the probe, a magnetostrictive element arranged in the probe rod, a force receiving element arranged in the probe, one end of the magnetostrictive element penetrating into the probe and connected with the force receiving element, and a piezoelectric element arranged in the probe. The single-point multi-azimuth magnetostrictive magnetic field change dynamic prediction device of the present application is arranged in a magnetic field, and the principle that the magnetostrictive element is deformed under the influence of the magnetic field is used to monitor the strength and direction of the magnetic field. When the magnetic field is non-uniform, the magnetostrictive element is deformed towards the direction with higher magnetic field strength, the force receiving element is deflected, and the piezoelectric element is pressed by the force receiving element. The piezoelectric element pressed in different ways sends different signals according to the force, thereby detecting the strength of the magnetic field. In addition, the magnetostrictive element is less affected by temperature, and is suitable for measuring in relatively harsh environments such as high temperature, and has strong anti-interference ability.

[0007] Further, specifically, the force receiving element is disc-shaped, each group of piezoelectric elements is provided with a plurality of piezoelectric elements along the circumference of the force receiving element, and each group of piezoelectric elements is reversely connected in series.

[0008] Further, the single-point multi-azimuth magnetostrictive magnetic field change dynamic prediction device further comprises an electronic bin connected with the end of the probe rod away from the probe.

[0009] Further, a support block is arranged in the probe, the support block is provided with a containing groove, the piezoelectric element and part of the force receiving element are located in the containing groove, and the piezoelectric element is connected with the side wall of the containing groove.

[0010] Further, a support rod is arranged in the probe rod and surrounds the magnetostrictive element.

[0011] Further, a vertical position detection device is further arranged, the vertical position detection device comprises a circuit board and a detection coil, the circuit board is connected with one end of the magnetostrictive element away from the force receiving element to provide a current pulse into the magnetostrictive element, the circuit board is further provided with an amplification circuit and a time chip, the amplification circuit is connected with the detection coil, the detection coil surrounds the magnetostrictive element, and the time chip is electrically connected with the amplification circuit.

[0012] The second aspect of the present application discloses a use method comprising the following steps:

[0013] Magnetic field intensity detection: the probe is vertically placed in the magnetic field to be measured, so that the magnetostrictive part is deformed under the influence of the uneven magnetic field, and then drives the stressed part to swing, so that the stressed part swings to the pressure part, and the pressure part is forced, and then the pressure part outputs a voltage signal.

[0014] Further, interference source finding: the probe is vertically placed in the magnetic field to be measured, the direction of the interference source is judged by observing the pressure part of the output voltage signal, the direction where the voltage value is higher is found, then the probe is moved towards the direction, after moving a distance, the output voltage signal of the pressure part is continuously observed until the voltage signal output by the pressure part tends to zero, and the position is the position of the interference source.

[0015] Further, the position determination step: the circuit board sends a current pulse to the magnetostrictive part, at this time the time chip starts timing, then the current pulse promotes the deformation of the magnetostrictive part to diffuse mechanical waves, the detection coil converts the detected mechanical waves into an electrical signal and transmits it to the time chip, when the time chip receives the signal of the detection coil, it stops timing, the distance between the deformation of the magnetostrictive part and the circuit board is calculated by the transmission time of the mechanical wave, and then the vertical position of the interference source is determined.

[0016] Further, in the interference source finding step, it also includes: after finding the direction where the voltage value is higher, rotating the probe circumferentially to further determine the direction of the interference source.

[0017] The beneficial effects of the present application are,

[0018] 1. The magnetostrictive part is used to measure the magnetic field intensity, the measurement accuracy is high, the measurement accuracy of the traditional magnetic field detection sensor is not high, and it cannot meet the requirement of high-precision measurement on site, while the resolution of the piezoelectric part is relatively high, and the theoretical measurement accuracy of the magnetostrictive effect can reach infinity, so that the theoretical measurement accuracy of the present application can reach a very considerable degree.

[0019] 2. The magnetostrictive part is less affected by temperature and is suitable for measurement in relatively harsh environments such as high temperature, the magnetostrictive phenomenon itself is less affected by temperature, and the relative error of measurement between minus 20 DEG C and plus 80 DEG C is still within the range that can meet the on-site use, compared with the temperature drift of the Hall sensor affected by temperature, this scheme can undoubtedly play a role in a wider measurement situation;

[0020] 3. The measurement range can be more extensive, compared with the electrical magnetic field detection sensor, this scheme can not only achieve point measurement, but also can achieve spatial measurement, and more measurement methods can make more choices in the face of different measurement situations.

[0021] 4. Only the parts such as the probe rod, magnetostrictive part, force receiving part and piezoelectric part are needed to realize the magnetic field monitoring, the structure is simple, the measurement cost is low, the structure is simple, and the manufacturing cost of each part is low, but the high measurement accuracy can still be realized;

[0022] 5. The device has high reliability, according to the tracking measurement, the magnetostrictive measurement device can achieve an average failure-free safe working time of 23 years, and even in high temperature, high pressure and strong vibration working conditions, excellent data output can still be realized;

[0023] 6. Compared with the traditional magnetic field detector measuring x-y plane, the vertical position detection device can realize the magnetic field positioning function in the z-axis direction, determine the height of the interference source, and realize the all-around multi-functional accurate measurement;

[0024] 7. Through the differential output mode of the piezoelectric part, the dynamic change trend measurement of the measured magnetic field can be realized, the real-time prediction of dynamic change can be realized in the field detection, and according to the stress condition of different piezoelectric parts, the measurement of the direction of the interference magnetic field can be realized, and a large amount of time for analyzing the numerical value change in the later stage is saved. BRIEF DESCRIPTION OF DRAWINGS

[0025] The application will be further described below in combination with the drawings and examples.

[0026] Figure 1 It is the structure diagram of the whole single-point multi-directional magnetostrictive magnetic field change dynamic prediction device.

[0027] Figure 2 It is the sectional structure diagram of the magnetostrictive part, force receiving part and piezoelectric part.

[0028] Figure 3 It is the curve diagram of the relationship between the magnetostrictive coefficient and the field strength.

[0029] Figure 4 It is the curve diagram of the relationship between the voltage and the displacement of the piezoelectric part.

[0030] Figure 5 It is the schematic diagram of the principle of the vertical position detection device.

[0031] In the figure: 1, electronic bin; 2, probe rod; 21, support rod; 22, magnetostrictive part; 3, probe; 31, support block; 311, containing groove; 32, force receiving part; 33, piezoelectric part; 34, amplification circuit; 35, detection coil; 36, measured magnetic field; 37, current pulse. DETAILED DESCRIPTION

[0032] The application will be described in further detail below with reference to the drawings. These drawings are simplified schematic diagrams which only show the basic structure of the application in a schematic manner and therefore only show the components relevant to the application.

[0033] The application discloses a single-point multi-azimuth magnetostrictive magnetic field change dynamic prediction device.

[0034] With reference to Figure 1 and Figure 2 The single-point multi-azimuth magnetostrictive magnetic field change dynamic prediction device comprises an electronic bin 1, a probe rod 2 fixedly connected to the electronic bin 1, and a probe head 3 fixedly connected to the probe rod 2. A circuit board is installed in the electronic bin 1, and a support block 31 is fixedly connected to the probe head 3. Two support blocks 31 are oppositely arranged along the length direction of the probe head 3. An accommodating groove 311 is formed at the opposite end of each support block 31, and a same force receiving piece 32 is arranged between the two accommodating grooves 311. A group of piezoelectric pieces 33 is arranged at each end of the force receiving piece 32 along the thickness direction of the force receiving piece 32. The piezoelectric pieces 33 are fixed to the side wall of the accommodating groove 311, and the gap between the piezoelectric pieces 33 and the force receiving piece 32 is 0.05-0.8 mm. The force receiving piece 32 is disc-shaped, each group of piezoelectric pieces 33 is uniformly arrayed along the circumferential direction of the force receiving piece 32, and the number of piezoelectric pieces 33 in each group is even, which can be two, four or six. Each two piezoelectric pieces 33 in each group are oppositely connected in series to output a differential signal, thereby reducing noise and achieving the purpose of magnetic field azimuth detection. A magnetostrictive piece 22 is fixedly connected to the force receiving piece 32, and the end of the magnetostrictive piece 22 away from the force receiving piece 32 is located in the probe rod 2. A support rod 21 is also fixedly connected to the probe rod 2 and is sleeved on the magnetostrictive piece 22 to provide support for the magnetostrictive piece 22. The gap between the support rod 21 and the magnetostrictive piece 22 is 0.5-1.5 mm.

[0035] When the magnetic field is uniform, the magnetostrictive piece 22 will only theoretically experience axial stretching and circumferential rotation. Since the piezoelectric pieces 33 on the same side of the force receiving piece 32 are oppositely connected in series, when the piezoelectric pieces 33 on the same side of the force receiving piece 32 are simultaneously stressed, the output voltage is zero. However, if the magnetic field intensity at a certain point is stronger than that in other regions, the corresponding position of the magnetostrictive piece 22 will be pulled to the stronger region, driving the force receiving piece 32 to swing away from it. At this time, the stress on the piezoelectric pieces 33 becomes different. For example, when the force receiving piece 32 swings towards one of the piezoelectric pieces 33, the stress on the piezoelectric piece 33 will be larger, while the stress on the piezoelectric piece 33 oppositely connected in series will be smaller. At this time, the output voltage of the voltage output end is determined by the piezoelectric piece 33 with larger stress.

[0036] When measuring, the probe 3 is placed in the magnetic field to be measured, and the staggered longitudinal magnetic field will be superimposed on the magnetostrictive element 22. According to the magnetostrictive principle, when the magnetostrictive material is affected by the alternating magnetic field, it will produce elongation or shortening changes in the magnetization direction. At the same time, due to the fact that the magnetic field in reality is necessarily uneven and unbalanced, and even easy to change. Therefore, when the unbalanced magnetic field is loaded on the magnetostrictive element 22, the magnetostrictive element 22 will also produce uneven expansion and contraction changes, which are transmitted to the force receiving element 32 through the magnetostrictive element 22, so that the force receiving element 32 not only moves up and down, but also swings left and right, front and back. These changes of the force receiving element 32 will act on the differential output piezoelectric element 33, so that the positive and negative directions of the electric signal output by the piezoelectric element 33 have consistency. In this way, the distribution of the magnetic field strength in each direction of the current point can be detected.

[0037] The deformation size of the magnetostrictive element 22 is generally expressed by the magnetostriction coefficient. The magnetostriction coefficient refers to the ratio of the elongation of the magnetostrictive material to the original length, commonly represented by a. The formula of the magnetostriction coefficient is as follows:

[0038] a = Δl / l

[0039] Where Δl is the elongation of the magnetostrictive material, and l is the original length of the magnetostrictive material.

[0040] Generally, the stronger the magnetic field, the longer the magnetostrictive element 22; the weaker the magnetic field, the shorter the magnetostrictive element 22. The relationship can be referred to Figure 3 .

[0041] The force generated by the deformation of the magnetostrictive material is known from Hooke's law:

[0042] F = K1·Δl

[0043] Where k is the stiffness coefficient of the magnetostrictive material.

[0044] Within a certain range, the voltage output and displacement change of the piezoelectric ceramic have a certain linear relationship. Given the force F on the piezoelectric ceramic, and again applying Hooke's law, the stiffness coefficient K 压电 of the piezoelectric ceramic can be obtained,

[0045] ΔL = F / K 压电

[0046] And the relationship between the deformation displacement of the piezoelectric material and the voltage value V is:

[0047] ΔL = d·V

[0048] Where d is the piezoelectric constant

[0049] The relationship between the piezoelectric material deformation displacement and the voltage value V is shown in the following curve fitting formula: Figure 4 Figure 4 The current voltage can be calculated by curve fitting, and the conversion from the field strength to the voltage is realized. Since the change of the magnetic field is generally periodic, the trend of the change of the magnetic field can be predicted through the continuous voltage change output by the piezoelectric element 33. The output of the magnetic field strength is realized by the MCU, and the calculation formula is stored in the MCU. The MCU calculates the data output by the piezoelectric element 33 and completes the output. The MCU uses an stm32f030k6t6 chip produced by Shenzhen Ding Sen Electronics Co., Ltd. In this embodiment, four piezoelectric elements 33 are provided, and the piezoelectric elements 33 are labeled as R1, R2, R3, and R4. The general output signal can be as shown in Table 1:

[0050] Voltage / V Magnetic field strength / T Output piezoelectric 3.3 0.5 R1

[0051] Table 1

[0052] In addition, the device can also be placed in the magnetic field to be measured, and the direction of the strong interference magnetic field can be judged by the voltage, and then the interference source can be found. When detecting the magnetic field strength, the direction can be judged according to the piezoelectric element 33 corresponding to the feedback signal. The magnetostrictive material drives the stressed element 32 to deflect towards the direction with higher magnetic field strength, so the direction of the piezoelectric element 33 that is pressed is the direction of the magnetic field. After the approximate direction of the magnetic field is determined, the probe 3 is moved a distance in that direction, which can be 1 meter or 3 meters. Then the measurement is continued. If the voltage value output by the piezoelectric element 33 in that direction decreases, it means that the direction is correct, and the movement continues until the voltage value output by the piezoelectric element 33 in a certain position is close to zero. Then the position is the interference source. In the process of finding the direction, the probe 3 can be rotated to further narrow the range of the direction of the interference source.

[0053] The magnetostrictive element 22 is designed in the form of a straight rod. When it is placed in the magnetic field to be measured, the magnetic field to be measured may have multiple points with strong magnetic field. According to the magnetostrictive principle, the magnetostrictive element 22 at the strong point will have a large torsional and telescopic deformation. The deformation will generate force transmission, and then mechanical waves will be generated. If there are multiple points with strong magnetic field, multiple points on the magnetostrictive element 22 will deform, and then multiple mechanical waves will be generated. The vertical position detection device is provided in the electronic bin. The mechanical waves transmitted through the magnetostrictive phenomenon are used to judge the position of the magnetic field. That is, by detecting the transmission time of the mechanical waves, the distances between the strong magnetic field points and the electronic bin 1 can be known, and the magnetic field distribution positioning in the Z-axis can be measured. Then, through the output judgment of the piezoelectric element 33 in the horizontal plane and the transmission time detection of the mechanical waves in the vertical plane, the approximate judgment of the magnetic field distribution can be achieved.

[0054] Referring to​Figure 5 The electronic bin 1 and the probe rod 2 are provided with a vertical position detection device, which includes a circuit board and a detection coil 35. The circuit board is fixedly connected in the electronic bin 1, and is fixedly connected with the magnetostrictive element 22 away from the force receiving element 32, and is electrically connected at the same time. The detection coil 35 is fixed on the inner wall of the support rod 21, and surrounds the magnetostrictive element 22. The circuit board is also provided with an amplification circuit 34 and a time chip. The amplification circuit 34 is electrically connected with the detection coil 35, and is also electrically connected with the time chip. In operation, the circuit board sends out a current pulse 37 to the magnetostrictive element 22, so as to make the deformation part of the magnetostrictive element 22 diffuse mechanical waves. The mechanical waves are detected by the detection coil 35, and an electric signal is transmitted to the time chip. The time chip starts timing when the current pulse 37 is sent out, and stops timing when the time chip receives the electric signal fed back by the detection coil 35. The distance between the deformation part of the magnetostrictive element 22 and the circuit board is calculated through the transmission time of the mechanical waves, and then the position of the interference source in the height direction is determined. The time chip can adopt the TDC-GP22 chip patch of the ACAM company.

[0055] From the current research, the speed of the mechanical waves transmitted on the magnetostrictive element 22 is constant and is about 2800m / s. Therefore, only the transmission time of the mechanical waves needs to be known to know the distance of the deformation point on the waveguide wire. At present, the transmission time of the mechanical waves is generally measured by using an RLC oscillation time chip or a timing chip. In the embodiment, the timing chip, i.e. the time chip, is used.

[0056] The magnetostrictive element 22 can adopt the terbium dysprosium iron rare earth super magnetostrictive alloy rod produced by Tongxian Metal Material (Shanghai) Co., Ltd., the piezoelectric element 33 is made of pzt4 piezoelectric ceramic, and the support block 31 is made of insulating material, such as glass.

[0057] In a second aspect, the application discloses a use method, which includes the following steps:

[0058] Interference source searching: the probe 3 is vertically placed in the measured magnetic field 36, the direction of the interference source is judged by observing the pressure of the output voltage signal, the direction where the voltage value is higher is found, then the probe 3 is moved towards the direction, and the output voltage signal of the pressure is observed after moving a distance, until the voltage signal output by the pressure tends to zero, and the position is the position of the interference source.

[0059] The vertical position determining step: the circuit board sends a current pulse 37 to the magnetostrictive element 22, at this time the time chip starts timing, then the current pulse 37 causes the deformation of the magnetostrictive element 22 to diffuse out mechanical waves, the detection coil 35 detects the mechanical waves and sends an electrical signal to the time chip, when the time chip receives the signal transmitted by the detection coil 35, it stops timing, the distance between the deformation of the magnetostrictive element 22 and the circuit board is calculated by the transmission time of the mechanical waves, and then the vertical position of the interference source is determined.

[0060] The above is the ideal embodiment according to the application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the application. The technical scope of the application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A single-point, multi-directional magnetostrictive magnetic field dynamic prediction device, characterized in that: include Probe (3); Probe (2), which is connected to probe (3); A magnetostrictive element (22) is disposed inside the probe (2); Force-receiving component (32), the force-receiving component (32) is located inside the probe (3), and one end of the magnetostrictive component (22) passes through the probe (3) and is connected to the force-receiving component (32); A piezoelectric element (33) is disposed inside the probe (3); two sets of piezoelectric elements (33) are provided along the thickness direction of the force-bearing element (32), and the two sets of piezoelectric elements (33) are disposed on both sides of the force-bearing element (32) along the thickness direction of the force-bearing element (32); The force-bearing component is disc-shaped, and multiple piezoelectric components are provided in each group along the circumference of the force-bearing component. The two piezoelectric components in each group are connected in series in opposite directions. It also includes a vertical position detection device, which includes a circuit board and a detection coil (35). The circuit board is connected to the end of the magnetostrictive member (22) away from the force-bearing member (32) to provide a current pulse (37) to the magnetostrictive member (22). The circuit board is also provided with an amplifier circuit (34) and a timing chip. The amplifier circuit (34) is connected to the detection coil (35). The detection coil (35) surrounds the magnetostrictive member (22). The timing chip is electrically connected to the amplifier circuit (34).

2. The single-point multi-directional magnetostrictive magnetic field change dynamic prediction device as described in claim 1, characterized in that: Also includes An electronic compartment (1) is connected to the end of the probe rod (2) away from the probe (3).

3. The single-point multi-directional magnetostrictive magnetic field change dynamic prediction device as described in claim 1, characterized in that: The probe (3) is provided with a support block (31), and the support block (31) is provided with a receiving groove (311). The piezoelectric element (33) and part of the force-bearing element (32) are located in the receiving groove (311), and the piezoelectric element (33) is connected to the side wall of the receiving groove (311).

4. The single-point multi-directional magnetostrictive magnetic field change dynamic prediction device as described in claim 1, characterized in that: The probe (2) is provided with a support rod (21), which is sleeved on the outside of the magnetostrictive component (22).

5. A method of using the single-point multi-directional magnetostrictive magnetic field change dynamic prediction device based on claim 4, characterized in that: Includes the following steps: Magnetic field strength detection: The probe (3) is placed vertically in the magnetic field to be measured (36), so that the magnetostrictive component (22) is deformed by the uneven magnetic field, which in turn drives the force-bearing component (32) to swing, causing the force-bearing component (32) to swing towards the pressure component, causing the pressure component to be subjected to force, and thus causing the pressure component to output a voltage signal.

6. The method of using the single-point multi-directional magnetostrictive magnetic field change dynamic prediction device as described in claim 5, characterized in that: It also includes the following steps: Finding the source of interference: Place the probe (3) vertically in the magnetic field to be measured (36), and determine the direction of the source of interference by observing the pressure of the output voltage signal. Find the direction of the point with higher voltage value, and then move the probe (3) in that direction. After moving a distance, continue to observe the pressure of the output voltage signal until the voltage signal output by the pressure is close to zero. This position is the location of the source of interference.

7. The method of using the single-point multi-directional magnetostrictive magnetic field change dynamic prediction device as described in claim 6, characterized in that: It also includes the following steps: Vertical position determination steps: The circuit board sends a current pulse (37) to the magnetostrictive component (22). At this time, the time chip starts timing. Subsequently, the current pulse (37) causes mechanical waves to spread from the deformation point of the magnetostrictive component (22). The detection coil (35) converts the detected mechanical waves into electrical signals and transmits them to the time chip. When the time chip receives the signal from the detection coil (35), it stops timing. The distance between the deformation point of the magnetostrictive component (22) and the circuit board is calculated by the transmission time of the mechanical waves, thereby determining the vertical position of the interference source.

8. The method of using the single-point multi-directional magnetostrictive magnetic field change dynamic prediction device as described in claim 6, characterized in that: The interference source locating step also includes: after finding the direction of the point with higher voltage value, rotating the probe (3) circumferentially along the probe (3) to further determine the direction of the interference source.

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