Arrayed active electric field sensor for identifying resources and method of detection thereof

Abstract

The application discloses an array active electric field sensor for identifying resources and a detection method thereof, and relates to the technical field of underwater detection. The array active electric field sensor for identifying resources comprises an acrylic plate, a sensor is arranged on the acrylic plate, the sensors are array distributed on the acrylic plate, the array distributed sensors form the array active electric field sensor, the sensor comprises an emitter and a receiver, mounting grooves for mounting the emitter and the receiver are arranged on the acrylic plate, the emitter is provided with eight rows, each row has eleven, the receiver is provided with four rows, each row is provided with six, and each electrode has the same length, width, shape and material. The application can provide a new detection scheme in a harsh environment by using the active electric field technology, can provide abundant data and more accurate positioning information by simultaneously working of multiple sensors in the array, and can judge material information of underwater resources according to the disturbance potential size obtained by each sensor.

Description

Technical Field

[0001] This invention relates to the field of underwater detection technology, and in particular to an array-type active electric field sensor for resource identification and its detection method. Background Technology

[0002] The underwater active electric field detection and localization technology of weakly electric fish has aroused widespread research interest in the field of bionics. Since the 1950s, biological researchers have conducted a series of studies on the active electric field detection phenomenon of weakly electric fish. As early as 1958, Machin and Lissmann et al. established a mathematical model of the active electric field detection and localization system of weakly electric fish through research on manta rays and conducted experimental verification. In the following decades, researchers continued to conduct in-depth research based on this, exploring the active electric field localization ability and electric field information perception ability of weakly electric fish.

[0003] A search revealed that patent application number CN201010242501.2 discloses an underwater active electric field imaging device, whose active electric field sensor has one pair of emitters and multiple pairs of receivers. This provides an imaging device for underwater vehicles capable of reflecting the geometric features of target objects in turbid water.

[0004] The above-mentioned patent has the following problems when used: 1. The emitters are too few and too far apart, and the difference between the potentials received by the receivers is very small, so it is impossible to obtain the potential difference information well.

[0005] 2. It only uses the active electric field for imaging to roughly describe the shape of the object, without analyzing the material of the object.

[0006] A search revealed that patent application number CN201910555953.7 discloses a method and device for detecting the shape of underwater objects based on the frequency domain. The method uses an underwater active electric field to detect the object multiple times from different positions in the same direction, processes the collected electric field information to obtain the turning frequencies at different positions in the same direction of the object, and then processes and determines the shape of the object in a single direction.

[0007] However, the aforementioned patent only uses frequency domain information to determine the shape of an object, but does not determine the material of the object. Summary of the Invention

[0008] The purpose of this invention is to provide an array-type active electric field sensor for identifying resources and a detection method thereof, thereby solving the technical problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: an array-type active electric field sensor for identifying resources includes an acrylic plate, on which sensors are disposed, and an array of sensors is distributed on the acrylic plate. The array of sensors constitutes an array-type active electric field sensor, and each sensor includes an emitter and a receiver. The acrylic plate is provided with mounting slots for mounting the emitter and receiver.

[0010] Preferably, the emitters are arranged in eight rows with eleven electrodes in each row, and the receivers are arranged in four rows with six electrodes in each row.

[0011] Preferably, each electrode has the same length, width, shape, and material, and the emitter and receiver are made of materials with good stability, good conductivity, and corrosion resistance.

[0012] Preferably, the exposed lengths of the emitter and receiver mounted on the acrylic plate are consistent.

[0013] Preferably, two adjacent emitters in the same row are connected to complementary square waves (i.e., 180° out of phase) but with identical amplitudes and other parameters.

[0014] A method for detecting resources using an array-type active electric field sensor includes the following steps: S1. Frequency test: During the test, a single sensor is fixed using a corexy structure, and a stepper motor is controlled to make the whole thing perform a 15cm*16cm scanning motion. That is, first the x 15cm is scanned, then the y moves forward 1cm, then the x moves back 15cm, and then the y moves forward 1cm again. This is repeated 8 times. The sensor returns to the receiving end to receive the potential and return the position information at the same time. Finally, the frequency is changed to continuously draw the graph. S2. Finally, the data graph can be obtained. According to the magnitude of the maximum disturbance potential (i.e., the maximum value of the difference between the potential difference when there is no object under the sensor and the potential difference when there is an object under the sensor), it can be seen that the effect gradually improves from 10Hz to 50Hz, and the effect does not change significantly from 50-1000Hz. Finally, the frequency of 50-1000Hz is selected. S3. The receiving electrode selects to use the built-in ADC of the microcontroller for data acquisition. Since there are enough of them, a smaller PCB board can be used for acquisition, which meets the space requirements when the robot is actually installed. S4. The robot goes into the water. After going into the water, it needs to first confirm that there is nothing under and around it. Then it performs differential processing between each adjacent receiving electrode and returns the position information to obtain a reference potential difference matrix X. S5. The robot moves and continuously generates a new potential difference matrix Xn; S6. Next, the newly generated potential difference matrix Xn is subtracted from the reference potential difference matrix X to obtain a new matrix Yn. Based on the magnitude of each value in Yn, it is determined whether there is a target object around. If it is confirmed that there is a target object around, it is determined what the target object is, its size, and its relative position to the robot.

[0015] Compared with related technologies, the array-type active electric field sensor and its detection method for identifying resources provided by this invention have the following advantages: 1. Highly Efficient Underwater Resource Detection: Traditional sonar sensors can only detect the shape of underwater resources, not their materials. Cameras are also unable to detect resources in murky water, low light, or no light conditions. In contrast, this invention utilizes active electric field technology to provide a new detection solution in harsh environments. By having multiple sensors in an array work simultaneously, abundant data and more accurate positioning information can be provided, and the material information of underwater resources can be determined based on the magnitude of the perturbation potential obtained from each sensor.

[0016] 2. Comprehensive Resource Identification Capability: This invention utilizes an active electric field sensor to identify the material and shape of underwater resources. By generating an excitation electric field and receiving feedback signals, the sensor can determine the type and size of underwater resources based on the degree of disturbance to the electric field by different materials. This comprehensive resource identification capability gives this invention significant application potential in underwater resource exploration and development.

[0017] 3. Economic and Practical: Compared with other underwater resource exploration technologies, the active electric field technology of this invention is extremely inexpensive. The active electric field sensor requires low-cost materials and can be manufactured using existing electronic components. This makes this invention economically practical in the field of resource exploration and development. Attached Figure Description

[0018] Figure 1 This is a sensor diagram of the present invention; Figure 2 This is a layout diagram of the present invention; Figure 3 This is a fish electric field analysis diagram of the present invention; Figure 4 This is a diagram of the corexy structure of the present invention; Figure 5 This is a schematic diagram of the 10Hz structure of the present invention; Figure 6 This is a schematic diagram of the 20Hz structure of the present invention; Figure 7 This is a schematic diagram of the 50Hz structure of the present invention; Figure 8 This is a schematic diagram of the 100Hz structure of the present invention; Figure 9This is a schematic diagram of the 200Hz structure of the present invention; Figure 10 This is a schematic diagram of the 500Hz structure of the present invention; Figure 11 This is a schematic diagram of the 1000Hz structure of the present invention; Figure 12 This is a flowchart illustrating the overall workflow of the present invention; Figure 13 This is a diagram illustrating the simultaneous identification of graphite and acrylic materials according to the present invention. Figure 14 This is a flowchart illustrating the process of detecting metallic objects according to the present invention.

[0019] In the diagram: 1. Acrylic plate; 2. Sensor; 201. Emitter; 202. Receiver. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Example 1: Please refer to Figures 1-2 The present invention provides a technical solution: an array-type active electric field sensor for identifying resources, including an acrylic plate 1, on which a sensor 2 is disposed, and the sensor 2 is arrayed on the acrylic plate 1. The array-distributed sensor 2 forms an array-type active electric field sensor. The sensor 2 includes an emitter 201 and a receiver 202. The acrylic plate 1 is provided with a mounting groove for mounting the emitter 201 and the receiver 202.

[0022] The transmitter 201 has eight rows with eleven electrodes in each row, and the receiver 202 has four rows with six electrodes in each row.

[0023] Each electrode has the same length, width, shape, and material. The emitter 201 and receiver 202 are made of materials with good stability, good conductivity, and corrosion resistance.

[0024] The electrodes are made of materials such as graphite and titanium, which are stable in water, have good electrical conductivity, and are corrosion resistant. The length and diameter can be determined according to the fixture.

[0025] The exposed lengths of the emitter 201 and receiver 202 installed on the acrylic plate 1 are consistent.

[0026] Among them, two adjacent emitters 201 in the same row are complementary (i.e., 180° out of phase) but have the same amplitude and other properties as square waves.

[0027] In this implementation scheme, the complementary PWM signal output by the microcontroller was selected as the transmission source for the final test. The test results showed that its load capacity was sufficient for use, and its output was relatively stable, with minimal impact on the measurement.

[0028] An array-type active electric field sensor was designed by utilizing the material recognition principle of a single sensor and the imaging principle of an array sensor.

[0029] Unlike the description in patent CN201010242501.2, we use multiple pairs of active electric field emitters instead of a single pair (although a weak electric fish is equivalent to a pair of emitters at the head and tail, the sensor manufacturing cost is increased if the distance is too far due to limitations in acquisition accuracy). The reason is that when the distance between the two emitters is too far, the differential signal between the intermediate receiver will decrease, which will lead to an increase in the signal-to-noise ratio and a decrease in measurement accuracy. Therefore, we use multiple pairs of active electric field emitters to solve the problem of slow single-sensor imaging speed in the single-pole differential model.

[0030] Example 2: Please refer to Figures 5-12 As shown, based on Embodiment 1, the present invention provides a technical solution: a method for detecting resources using an array-type active electric field sensor, comprising the following steps: S1. Frequency test: During the test, a single sensor is fixed using a corexy structure, and a stepper motor is controlled to make the whole thing perform a 15cm*16cm scanning motion. That is, first the x 15cm is scanned, then the y moves forward 1cm, then the x moves back 15cm, and then the y moves forward 1cm again. This is repeated 8 times. The sensor returns to the receiving end to receive the potential and return the position information at the same time. Finally, the frequency is changed to continuously draw the graph. S2. Finally, the data graph can be obtained. According to the magnitude of the maximum disturbance potential (i.e., the maximum value of the difference between the potential difference when there is no object under the sensor and the potential difference when there is an object under the sensor), it can be seen that the effect gradually improves from 10Hz to 50Hz, and the effect does not change significantly from 50-1000Hz. Finally, the frequency of 50-1000Hz is selected. S3. The receiving electrode selects to use the built-in ADC of the microcontroller for data acquisition. Since there are enough of them, a smaller PCB board can be used for acquisition, which meets the space requirements when the robot is actually installed. S4. The robot goes into the water. After going into the water, it needs to first confirm that there is nothing under and around it. Then it performs differential processing between each adjacent receiving electrode and returns the position information to obtain a reference potential difference matrix X. S5. The robot moves and continuously generates a new potential difference matrix Xn; S6. Next, the newly generated potential difference matrix Xn is subtracted from the reference potential difference matrix X to obtain a new matrix Yn. Based on the magnitude of each value in Yn, it is determined whether there is a target object around. If it is confirmed that there is a target object around, it is determined what the target object is, its size, and its relative position to the robot.

[0031] In this implementation plan, such as Figure 3 The image shows the electric field generated by a weak electric fish and the situation when there are objects around it. When an object with a resistivity higher than that of seawater appears in the detection electric field area, the current flows along the path of lower resistance, thus showing a tendency for the electric field lines to bypass the object being measured.

[0032] This redistribution of the electric field affects the electric field on the fish's body surface, which is then sensed by the fish's cells. This is similar to the object being measured being projected into the probe electric field, allowing weakly electric fish to obtain information about the object's location, geometry, and even resistivity by detecting changes in the electric field.

[0033] When an object with a resistivity lower than that of seawater appears in the detection electric field region, according to the law that current flows towards the path of lower resistance, the electric field lines will tend to enter the object being measured, as if the electric field lines are "absorbed" by the object being measured, which is the opposite of the situation with high resistivity objects.

[0034] In deep-sea environments, the method by which weak electric fish with declining visual abilities navigate, hunt, and evade predators by emitting their own sensory electric fields has gradually been recognized, thus providing new ideas and references for the navigation and positioning methods of underwater robots and vehicles.

[0035] According to existing research, the greater the difference in electrical conductivity between the identified object and its surrounding environment, the better the identification effect. Underwater organisms and other materials all have differences in electrical conductivity. Based on the theory of active electric field identification, the research on an active underwater rapid identification method based on electric field positioning technology is theoretically feasible.

[0036] When working, a square wave of a certain frequency needs to be emitted, or a sine wave can also be used, but a DC power supply cannot be used, because a DC power supply will electrolyze water underwater, and the generated hydrogen gas will adhere to the emitter and receiver electrodes, affecting the measurement.

[0037] Since we are doing something similar to biomimicry, and the frequency of the excitation source that the weak electric fish can emit is basically below 1kHz, the subsequent frequency selection is basically considered to be below 1kHz.

[0038] For frequency testing, a single sensor was selected, where each electrode was identical in length, width, shape, and material. It was considered a rectangle, with the electrode along one long axis serving as the emitter and the other as the receiver.

[0039] Use during testing, such as Figure 4 The corexy structure shown fixes a single sensor. The final result is as follows: Figures 5-11 The data graph shows that the performance gradually improves from 10Hz to 50Hz, but the performance changes little between 50Hz and 1000Hz. Therefore, a frequency range of 50-1000Hz can be chosen.

[0040] As for the issue of emission amplitude, tests have shown that it has no significant impact on the measurement results. Therefore, we can choose an excitation source with the smallest possible amplitude to avoid harming underwater organisms during detection and to save energy.

[0041] The receiver selects to use the built-in ADC of the microcontroller for data acquisition. Since there are enough of them, a small PCB board can be used for acquisition, which meets the space requirements of the actual robot installation.

[0042] When the receiving pole receives data, it does not return it directly. Instead, it performs differential analysis between adjacent receiving poles and then returns the differential data, along with the location information.

[0043] The reason for differential scanning is that with more emitters, the resulting electric field is more complex, which means that the data collected by each receiver cannot uniformly reflect the surrounding situation. This means that subsequent data processing requires individual processing for each sensor before it can be used. At the same time, the data processing methods may differ when the sensor detection height or the object being detected is different, which will cause great difficulties in data processing. However, if differential scanning is performed between adjacent sensors, the returned data can accurately and uniformly reflect the position, size, type, and other information of the measured object.

[0044] Example 3: Please refer to Figure 14 As shown, based on Embodiment 1 and Embodiment 2, the present invention provides a technical solution: an array-type active electric field sensor detection method for identifying resources. When detecting metal, the workflow needs to be modified, including the following steps: S1. First, you need to set the frequency to 10Hz at the beginning.

[0045] S2. Then, when a significant change occurs and the measured object exhibits low conductivity, the frequency is incremented by one each time a new potential difference matrix is ​​sampled.

[0046] S3. If the change value does not fluctuate significantly at 100 Hz, it is determined to be a non-metallic low-conductivity object. If fluctuation occurs, continue to increase the frequency until the object exhibits the same properties as the surrounding water. Record the frequency at this point and determine what metal it is.

[0047] In this implementation plan, such as Figure 13 The image shows the host computer used after the robot is submerged. This is primarily for the observer's convenience, allowing them to clearly see the properties, size, and relative position of the object being tested relative to the robot. During the test, a 5cm long, 4mm diameter graphite rod with high conductivity and a 5cm long, 3cm wide, 6mm thick acrylic sheet with low conductivity were used. In the image, the convex part is the graphite rod, and the concave part is the acrylic sheet.

[0048] Most objects can be identified using the above method. However, for metals and metal alloys, there is a detection dead zone. When the active electric field is at a low frequency, detecting metals will yield the same data as low-conductivity objects. But as the frequency gradually increases to above a certain level, the metal will once again exhibit the characteristics of high-conductivity objects.

[0049] Each metal has a different transition frequency, mostly between 50-100 Hz, which provides a theoretical basis for identifying various metals. Therefore, if the specific detection task is to detect metals, the workflow needs to be modified accordingly.

Claims

1. An array-type active electric field sensor for identifying resources, comprising an acrylic plate (1), characterized in that: Sensors (2) are provided on the acrylic plate (1). The array of sensors (2) is distributed on the acrylic plate (1). The array of sensors (2) forms an array-type active electric field sensor. The sensor (2) includes an emitter (201) and a receiver (202). The acrylic plate (1) is provided with mounting slots for the emitter (201) and receiver (202) to be installed. The emitter (201) is arranged in eight rows with eleven electrodes in each row, and the receiver (202) is arranged in four rows with six electrodes in each row; Two adjacent emitters (201) in the same row are connected to square waves with a phase difference of 180° and the same amplitude; The detection method for identifying underwater resources using the array-type active electric field sensor includes the following steps: S1. Frequency test: The final frequency range of 50-1000Hz was selected; S2. The receiving electrode selects to use the built-in ADC of the microcontroller for data acquisition. Since there are enough of them, a smaller PCB board can be used for acquisition, which meets the space requirements when the robot is actually installed. S3. The robot goes into the water. After going into the water, it needs to first confirm that there is nothing under and around it. Then it performs differential processing between each adjacent receiving electrode and returns the position information to obtain a reference potential difference matrix X. S4. The robot moves and continuously generates a new potential difference matrix Xn; S5. Next, the newly generated potential difference matrix Xn is subtracted from the reference potential difference matrix X to obtain a new matrix Yn. Based on the magnitude of each value in Yn, it is determined whether there is a target object around, or if it is confirmed that there is a target object around, it is determined what the target object is, its size, and its relative position information with the robot.

2. The array-type active electric field sensor for identifying resources according to claim 1, characterized in that: Each electrode has the same length, width, shape, and material. The emitter (201) and receiver (202) are made of materials with good stability, good conductivity, and corrosion resistance.

3. The array-type active electric field sensor for identifying resources according to claim 1, characterized in that: The exposed lengths of the emitter (201) and receiver (202) mounted on the acrylic plate (1) are consistent.

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