Ice layer thickness detection method based on resistance-capacitance integrated induction technology

Abstract

The invention discloses an ice layer thickness detection method based on a resistance-capacitance integrated induction technology, and the method comprises the steps: employing a coplanar multi-electrode capacitive sensor: forming a coplanar multi-electrode array through m parallel strip-shaped electrodes which are uniformly distributed on the same plane of a substrate in the vertical direction; and each contact pair is formed by taking one end of a strip-shaped electrode as a contact I and taking an independent loop point which is arranged on the substrate at the same horizontal height as the contact I as a contact II. A resistance-capacitance integrated multi-parameter fusion detection mechanism is creatively adopted, the accuracy and reliability of ice layer thickness and under-ice water level measurement results are greatly improved, data are automatically collected through a sensor and a circuit, the traditional operation mode that punching measurement depends on manual work on the ice surface is thoroughly changed, and the accuracy and reliability of the ice layer thickness and under-ice water level measurement results are greatly improved. Therefore, the working efficiency is greatly improved, the monitoring personnel are prevented from working in a severe and dangerous ice surface environment, and the personal safety is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of hydrological monitoring technology, specifically to a method for detecting ice layer thickness based on resistive-capacitive inductive sensing technology. Background Technology

[0002] The formation and melting of ice is a natural phenomenon, especially in high-latitude regions where lakes and rivers freeze due to changes in winter climate conditions. River freezing is also a natural phenomenon, occurring according to the river's course and the direction of water flow. The formation and melting of river ice and the movement of ice floes are important factors affecting the safety of rivers and their basins. Therefore, effective monitoring and forecasting of ice conditions are essential for effective ice floe protection and are a crucial issue that must be considered in river management. As temperatures rise, river ice melts, forming ice floes. If prevention and control measures are not implemented properly or promptly, they can jeopardize river safety and, in severe cases, cause natural disasters. In recent years, river ice floe disasters have mainly manifested in the following ways: (1) Ice Dams and Floods. Ice-water mixtures are common in rivers. When ice and water mix and flow, ice blocks often accumulate in the riverbed, forming ice dams that block normal water flow and increase water resistance. Ice dam accumulation will cause the river level to rise. If the water overflows the dam, it will cause ice jams and floods.

[0003] (2) Ice flower blockage. When suspended ice blocks appear, due to the low surface temperature, the ice blocks will stick together and gradually thicken and increase in number, which may completely block the flow of water. For example, the water inlet of the power station will block the trash rack and prevent the water from flowing through. The water level upstream will also overflow, forming ice jam flood disaster.

[0004] (3) Threatens the safety of river structures. When ice blocks on the river surface freeze, they will generate a large amount of power. The rapid movement of the ice blocks will have an impact on the structures on the river surface, affecting the safety of the structures. At the same time, the banks and structures covered by ice will undergo physical changes such as expansion and contraction with temperature changes, causing the structure of hydraulic structures to loosen and affecting the stability of the structures.

[0005] The Yellow River is one of my country's major rivers and the largest river in northern my country, with a drainage area of ​​750,000 square kilometers. Due to its vast basin, the middle and upper reaches experience low winter temperatures, often leading to freezing. As spring arrives and temperatures rise, ice jams are more likely to occur. Particularly in the Ningxia Hui Autonomous Region, Inner Mongolia Autonomous Region, and Shandong section, the Yellow River's natural flow is from south to north. In these areas, winter temperatures gradually decrease with increasing latitude. During freezing, the ice flows from downstream to upstream, and during thawing, it flows from upstream to downstream, easily causing ice jams that block the river channel. This blockage causes the river level to rise, resulting in significant ice floods.

[0006] In summary, ice jam disasters pose significant challenges to river management and flood control during the ice-jam season. Therefore, preventing ice jam disasters and conducting real-time monitoring of river ice and water conditions are crucial to promptly eliminating potential safety hazards. Analyzing collected ice and water condition data and combining it with historical changes in ice and water conditions are essential to predicting potential ice jam disasters and effectively preventing their occurrence.

[0007] Automatic monitoring of ice thickness and its changes is fundamental to the effective prevention of river ice jam disasters. Analyzing these data changes allows for the study of ice formation and melting processes in rivers, playing a crucial role in early warning and prevention of ice blockages and ice jam floods. Currently, hydrological monitoring of ice thickness and subglacial water levels relies heavily on manual measurement, typically involving drilling holes in the ice surface. Data collection and reporting are also done manually, resulting in low accuracy and efficiency. Real-time data reporting is also difficult, and the monitoring work carries inherent risks due to the harsh environment. Therefore, this invention provides an ice thickness detection method based on resistive-capacitive inductive sensing technology to achieve an automatic monitoring system for river ice thickness and water levels, meeting the accuracy requirements for ice jam control sampling data and the need for high reliability monitoring under complex climatic conditions. Summary of the Invention

[0008] The technical problem this invention aims to solve is to overcome existing defects and provide an ice thickness detection method based on resistive-capacitive induction technology. It creatively employs a multi-parameter fusion detection mechanism of "resistive-capacitive induction," significantly improving the accuracy and reliability of ice thickness and sub-ice water level measurements. Data is automatically collected through sensors and circuits, and the traditional method of relying on manual drilling on the ice surface for measurement is completely changed. This greatly improves work efficiency, avoids the need for monitoring personnel to work in harsh and dangerous ice environments, ensures personal safety, and effectively solves the problems in the background technology.

[0009] To achieve the above objectives, the present invention provides the following technical solution: an ice layer thickness detection method based on RC inductive sensing technology, comprising a coplanar multi-electrode capacitive sensor: m parallel strip electrodes uniformly distributed in the vertical direction on the same plane of the substrate to form a coplanar multi-electrode array; m resistor contact pairs: Each contact pair consists of one end of a strip electrode as contact one, and an independent loop point set at the same horizontal height on the substrate as contact two; m temperature sensors: each corresponding to one of m resistor contact pairs and arranged on the substrate at the same horizontal height; The detection method includes the following steps: Capacitance detection steps: m parallel strip electrodes are used as a coplanar multi-electrode capacitance sensor. The controller controls a multi-channel analog switch to sequentially apply sinusoidal AC excitation signals to the selected excitation electrodes and simultaneously measure the response voltage signals of each electrode. After rectification, filtering and A / D conversion, the response voltage signals are processed by the processor according to a predetermined voltage-dielectric relationship model to determine the proximity of air, ice or water medium to each electrode and obtain the first medium interface information. Resistance and temperature detection steps: The controller sequentially selects resistance contact pairs at different heights through a multi-channel analog switch, that is, a detection signal is applied between contact one and contact two and the resistance value between them is measured; at the same time, temperature data from temperature sensors at the same height as each selected contact pair is collected; based on the resistance value and temperature data, and according to the predetermined resistance-temperature-medium relationship model, the contact condition between air, ice or water medium and each contact pair is determined, and the second medium interface information is obtained; Data fusion and thickness calculation steps: Integrate the information of the first medium interface and the information of the second medium interface, perform data fusion and cross-validation, and calculate the ice layer thickness and the water level under the ice.

[0010] As a preferred embodiment of the present invention, in the capacitance detection step, the sinusoidal AC excitation signal is a sine wave with a peak value of 5V and a frequency of 60KHz.

[0011] As a preferred embodiment of the present invention, the strip electrode is a copper foil electrode.

[0012] As a preferred embodiment of the present invention, in the capacitance detection step, the controller controls the multi-channel analog switch to select the excitation electrodes in a top-down or bottom-up sequence.

[0013] As a preferred embodiment of the present invention, in the resistance and temperature detection step, the controller selects the resistance contact pairs in a bottom-up sequence.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The ice thickness detection method based on the RC inductive induction technology of this invention creatively adopts a multi-parameter fusion detection mechanism of "RC inductive induction". It responds quickly and non-contactly to changes in the medium through capacitance detection, accurately distinguishes water, ice and air through resistance detection, and uses temperature data as a key criterion. It effectively solves the problem that the traditional resistance method is difficult to identify the mixed state of ice and water. The three technologies verify and complement each other, which significantly reduces the misjudgment rate of the medium state, thereby greatly improving the accuracy and reliability of the ice thickness and water level measurement results.

[0015] 2. The ice thickness detection method based on RC inductive sensing technology exemplified in this invention features a "RC inductive sensor" that highly integrates the capacitive sensing electrode, the resistive contact pair, and the temperature sensor in a physical structure. The multiple electrodes on the same surface are used for capacitance detection, and their endpoints also form resistive contact pairs with independent loop points, realizing the reuse and optimization of hardware resources. This integrated design not only simplifies the sensor structure and reduces cost and installation complexity, but also ensures a high degree of consistency in the spatial position of the three signals: capacitance, resistance, and temperature, laying a physical foundation for accurate data fusion and calculation.

[0016] 3. The ice thickness detection method based on resistive-capacitive inductive technology exemplified by the present invention mainly relies on electrical and temperature signals in the detection process. It is less affected by complex climatic conditions such as visibility and wind and snow. Through reasonable circuit design and signal processing, it can operate stably in harsh environments such as low temperature and high humidity in river sites, meeting the strict requirements of high reliability of monitoring equipment for ice control work.

[0017] 4. The ice thickness detection method based on resistive-capacitive inductive technology exemplified by this invention automatically collects data through sensors and circuits, completely changing the traditional operation mode that relies on manual drilling on the ice surface for measurement. This greatly improves work efficiency, avoids monitoring personnel working in harsh and dangerous ice surface environments, and ensures personal safety. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of an ice thickness sensor and its system according to an embodiment of the present invention; Figure 3 This is a block diagram illustrating the principle of DDS in an embodiment of the present invention. Figure 4 This is a circuit diagram of a low-pass filter according to an embodiment of the present invention; Figure 5 This is a minimum system circuit diagram according to an embodiment of the present invention; Figure 6 This is a graph showing the ice layer change curves from two measurements in an embodiment of the present invention; Figure 7 This is a voltage change curve obtained by continuously collecting data from the bottom to the top electrode in an embodiment of the present invention; Figure 8 The voltage curve obtained by the resistance-temperature sensing acquisition system in this embodiment of the invention is shown in the figure. Figure 9 This is a temperature curve collected on-site in an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 The present invention provides a technical solution: an ice layer thickness detection method based on RC inductive technology, including a coplanar multi-electrode capacitive sensor: m parallel strip electrodes uniformly distributed in the vertical direction on the same plane of the substrate to form a coplanar multi-electrode array; m resistor contact pairs: Each contact pair consists of one end of a strip electrode as contact one, and an independent loop point set at the same horizontal height on the substrate as contact two; m temperature sensors: each corresponding to one of m resistor contact pairs and arranged on the substrate at the same horizontal height; The detection method includes the following steps: Capacitance detection steps: m parallel strip electrodes are used as a coplanar multi-electrode capacitance sensor. The controller controls a multi-channel analog switch to sequentially apply sinusoidal AC excitation signals to the selected excitation electrodes and simultaneously measure the response voltage signals of each electrode. After rectification, filtering and A / D conversion, the response voltage signals are processed by the processor according to a predetermined voltage-dielectric relationship model to determine the proximity of air, ice or water medium to each electrode and obtain the first medium interface information. Resistance and temperature detection steps: The controller sequentially selects resistance contact pairs at different heights through a multi-channel analog switch, that is, a detection signal is applied between contact one and contact two and the resistance value between them is measured; at the same time, temperature data from temperature sensors at the same height as each selected contact pair is collected; based on the resistance value and temperature data, and according to the predetermined resistance-temperature-medium relationship model, the contact condition between air, ice or water medium and each contact pair is determined, and the second medium interface information is obtained; Data fusion and thickness calculation steps: Integrate the information of the first medium interface and the information of the second medium interface, perform data fusion and cross-validation, and calculate the ice layer thickness and the water level under the ice.

[0021] Furthermore, in the capacitance detection step, the sinusoidal AC excitation signal is a sine wave with a peak value of 5V and a frequency of 60KHz.

[0022] Furthermore, the strip electrode is a copper foil electrode.

[0023] Furthermore, in the capacitance detection step, the controller controls the multiplex analog switch to select the excitation electrodes in either a top-down or bottom-up sequence.

[0024] Furthermore, in the resistance and temperature detection steps, the controller selects the resistance contact pairs in a bottom-up sequence.

[0025] The RC-inductive ice thickness detection method involves sequentially detecting air, ice, and water as three layers. It relies on the differences in dielectric constants and resistive properties among these three media. When the electrode contacts are in contact with each of the three media (air, ice, and water), the voltage values ​​collected at each layer will show significant differences. The measurement range of the RC sensor depends on its designed length, and its sensitivity is related to its structural design.

[0026] The most important static parameters of this sensor are the measurement range of capacitance and resistance for each electrode contact pair. This is reflected at the acquisition points as the voltage-capacitance relationship curve and the voltage-resistance change curve for each electrode contact. For a single electrode contact, the capacitance measurement range is related to the frequency of the sinusoidal excitation signal and the voltage divider resistor R, while the resistance measurement range is related to the temperature of the ice-water medium.

[0027] This invention creatively adopts a multi-parameter fusion detection mechanism of "resistance and capacitance in one", which greatly improves the accuracy and reliability of ice thickness and water level measurement results. It automatically collects data through sensors and circuits, and completely changes the traditional operation mode that relies on manual drilling on the ice surface for measurement. This greatly improves work efficiency, avoids monitoring personnel working in harsh and dangerous ice surface environments, and ensures personal safety.

[0028] The following is an example: like Figure 2-9 As shown: The specific modules of the solution involved in this embodiment are as follows: like Figure 2 As shown, the ice thickness detection system consists of two parts: a sensor acquisition unit and a measurement and control data processing unit. The sensor acquisition unit includes: copper foil electrodes, excitation signals, multiplex analog switches, rectifier detectors, and filter circuits; the measurement and control data processing unit includes: a low-power microcontroller processor, an analog-to-digital converter, a data storage device, and a signal transmission modem.

[0029] In the capacitive sensor unit circuit, a sinusoidal signal is sent to the input terminal of a multiplexer. After being selected by the multiplexer, it connects to the electrodes of the capacitive sensor. Seven out of the eight output terminals of each multiplexer are connected to the electrodes, and the remaining one connects to the shielded drive electrode. During fabrication, 140 copper foil strip electrodes are mounted on the substrate and connected by 20 multiplexer circuits. Specifically, the multiplexers are used to connect the sinusoidal excitation signal to multiple electrodes on the capacitor plate, taking into account the influence of the electric field on the capacitor electrodes. Devices with low on-resistance and low capacitive reactance should be used. Since this capacitive sensor consists of a set of parallel copper foils, its working mechanism requires that when one of the copper foil electrodes is connected to a sinusoidal excitation signal, the other electrodes must be connected to "ground". The MAX4761 is an 8-channel single-pole double-throw switch with a low capacitance of 2.0Ω on-resistance. The sensor has 140 electrodes, and each multi-channel analog switch can connect 7 electrodes. Therefore, 20 MAX4761s are needed. This device is selected as the multi-channel analog switch for this design to meet the requirements and is suitable for this design.

[0030] Capacitance detection principle: The microcontroller is the core of the control circuit, controlling multiple analog switches. From top to bottom, it sequentially selects and connects the measurement circuit, so that the sinusoidal signal is applied to the connecting electrode, while the other electrodes are grounded. The sinusoidal AC signal forms a capacitance between the copper foil electrode and other electrodes, and a capacitance between the copper foil electrode and the dielectric. The signal flows back to the "ground" electrode of the sinusoidal power supply. It is converted into a DC signal by the rectifier and detector circuit, and then the interference signal is filtered out by the filter circuit. The obtained DC voltage signal is sent to the signal acquisition module. The microcontroller controls the built-in 12-bit A / D analog-to-digital converter module to acquire data and convert it into digital quantity for storage. The above operation is repeated from top to bottom to obtain a set of voltage data, which is then sent to the PC through the GSM network.

[0031] In this system, the sinusoidal signal frequency is fixed and the average signal value is large, thereby obtaining a high signal-to-noise ratio and preventing signal noise interference. The noise can be further suppressed and the signal-to-noise ratio improved by using a bandpass amplifier.

[0032] like Figure 3 As shown, the sinusoidal excitation signal required in the sensor is obtained using DDS direct digital frequency synthesis technology. The signal frequency is 60kHz and the amplitude is 5V. It has the characteristics of short frequency switching time, wide operating frequency range, high frequency resolution, continuous phase change and easy modulation of the output signal.

[0033] like Figure 4As shown, there are three common types of frequency response characteristics for filters: Butterworth, Chebyshev, and elliptic. This embodiment uses the AD9850 chip to implement a sinusoidal signal. The sinusoidal output signal spectrum contains the fundamental pulse wave harmonic spectrum. Compared to a regular sinusoidal signal, its frequency is higher. To reduce high-frequency harmonic interference, a second-order Butterworth low-pass filter is suitable for obtaining a pure sine wave. This filter is characterized by high dynamic response speed and low phase lag, which meets the signal transmission requirements.

[0034] like Figure 5 As shown, considering the conditions for measuring the ice thickness of the Yellow River, the ultra-low power microcontroller MSP430 series from Texas Instruments was selected, which is most suitable for use in portable measuring equipment. The microcontroller control system consists of functional modules such as the microcontroller minimum system, power supply module, keyboard input, display output, data storage, decoding circuit, and wireless remote transmission. J1-J4 are used for interface connection with external devices.

[0035] This embodiment features a total of 6 keys, employing a non-encoded independent keyboard for input. Keyboard input is implemented via interrupts. The 6 keys are defined as follows: 4 directional keys ("Up", "Down", "Left", and "Right"), a "Function" key, and an "OK" key. The system display uses an LCM12232-9 LCD module. Data transmission is achieved by connecting the microcontroller's data bus to the module's data line. Control signals are connected to the microcontroller's address lines. The microcontroller's read / write control port controls the module's read / write operations.

[0036] The system in this embodiment needs to save the collected data and send the processed data to the monitoring center via GSM. Due to the large data storage requirement, this design selects an 8Gb SD card as the storage. Since the data transmission speed requirement is not high, the SPI transmission mode is used.

[0037] To ensure that the electrodes of the capacitive sensor conduct sequentially from top to bottom, an analog switch is required for control. The selection of the analog switch is achieved by a decoding circuit, which uses a 74HC573 latch chip in the circuit design. The selection of the capacitive sensor's sensing electrode is related to the output of the decoding circuit. After the chip select signal activates the latch, the decoded value is written into the latch and latched when the next drive clock pulse arrives. The multiplexed analog switch executes the latch's output signal to determine the selected electrode.

[0038] Because the serial port level of the MSP430 microcontroller is TTL level, which is incompatible with the electrical characteristics of RS232, the input / output levels of the serial port need to be converted. Therefore, the communication between the system and the GPRS DTU is implemented using the asynchronous communication interface circuit MAX3232. The microcontroller sends and receives data through these four ports, and the MAX3232 converts the RS232 electrical characteristic level signals.

[0039] The clock circuit is used to periodically wake up the CPU to perform data acquisition tasks and simultaneously saves the clock signal data along with the acquired ice thickness data to form a complete data report. This design uses the SD2200L series chip, which has a built-in crystal oscillator, can transmit data via I2C bus, and is a high-precision real-time clock chip. When not acquiring data, the CPU is in sleep mode, and the timer wakes the CPU to perform data acquisition when the set clock expires, thereby reducing system power consumption.

[0040] Based on the hardware described above, the actual application of this embodiment in measurement is as follows: A resistive-capacitive inductive ice thickness sensor was used to measure the ice thickness on the Yellow River surface twice. Figure 6 Based on the measured data curves, the ice thickness measured by the RC inductive ice thickness sensor is very close to the ice thickness measured manually on-site, with the two curves basically overlapping.

[0041] from Figure 6 As can be seen from the graph, there is a certain error between the data measured by the RC inductive ice thickness system and the actual measured data of the river ice thickness, with a maximum error of about 2 cm. Of course, this error may be due to systematic errors, and the data measured manually on-site is related to factors such as the placement of the measuring ruler and the angle of visual estimation, thus also resulting in errors in the manual measurement and reading of data.

[0042] During on-site measurements, the thickness of the ice layer at fixed points was continuously measured throughout the entire freezing process. Based on the sensor's electrode node arrangement, the voltage values ​​of the 5th, 19th, 29th, and 50th electrode contacts were measured vertically upwards, sequentially from bottom to top (water, ice, air). The measurement results show the following... Figure 7The voltage curves shown clearly indicate that the fifth electrode contact is below the water surface. When the voltage at this contact changes significantly, it means the water state around it has changed from liquid to solid ice, and the voltage value jumps from 1.7V to approximately 2.9V. The voltage curves for each electrode contact show that before the medium (water) around the fifth electrode contact changes state (before becoming ice), the voltage fluctuation range at this contact is relatively small. After the water around the 19th and 29th electrode contacts freezes into ice, the electrode voltages show similar fluctuations to those around the 50th electrode contact, with smaller fluctuations. The trend of the voltage fluctuation is similar to that of the 50th electrode contact. The curve shows that the electrode voltage in the air and ice layer is related to the temperature around the contact and fluctuates due to temperature changes. The fluctuation trends are basically the same, indicating that the effect of temperature on the voltage values ​​of the contacts in the air and ice layer is basically the same. Although the voltage change trends of the 19th and 29th electrode contacts are basically the same, the voltage value of the 19th electrode contact is slightly higher than that of the 29th electrode contact. After analysis, the basic judgment is that the water content in different areas of the ice layer is different. The water content in the upper part of the ice layer is less than that in the lower part of the ice layer, or the temperature of the ice closer to the bottom is higher than that in the upper part of the ice layer.

[0043] To understand the resistivity characteristics of different water qualities, as well as the resistivity and capacitance characteristics of ice-water mixtures, and to obtain the temperature change trend within the ice layer, it is necessary to derive the change pattern from the temperature change curve. This requires storing the capacitance, resistance, and temperature values ​​collected by the resistance-capacitance sensor on-site. The large amount of data collected and stored on-site is then reflected in the form of change curves. For example, the voltage value data curve collected by the resistance-temperature sensor is shown below. Figure 8 As shown; through the Figure 8 Analysis reveals clear interfaces within the ice layer, from bottom to top: water, ice, and air. Each interface between two media exhibits a sudden voltage change. Within the same medium, the measured voltage values ​​show relatively stable contact voltages, remaining at a horizontal level. The voltage at the electrode contact point in contact with the water fluctuates between 3V and 3.5V. When the voltage drops below 3V, a noticeable voltage change occurs, indicating the entry into the ice layer. The boundary between the ice layer and air is also relatively clear, with the voltage at the electrode contact point around 0.5V. These voltage values ​​at these interfaces show that the ice layer voltage varies between 0.5V and 3V, primarily influenced by the varying water content. Analysis of the curves in the graph indicates that the ice layer thickness is approximately 0.4 meters.

[0044] In the RC sensor, a temperature sensor is placed at 5cm intervals. This temperature sensor corresponds to the electrode contact that collects the ice layer thickness. The collected temperature data is processed and plotted as a curve, as shown below. Figure 9 As shown, it can be seen that the temperatures collected by the temperature sensor electrodes 16 to 25, which are in contact with the ice layer on the river surface, change with the ambient temperature, and the trend is basically the same as that of the air temperature. The temperatures collected by the electrodes 1 to 14 are the water temperature under the ice layer, which is basically around 0℃. The temperatures collected by the electrodes in the air are also basically the same. However, the temperature inside the ice layer varies between the different temperature sensor electrodes, and it is a nearly linear curve. Since the air temperature is lower than the water temperature, the temperature of the contact points closer to the air is lower, and the temperature of the contact points closer to the water surface is higher.

[0045] In summary, the ice thickness in the river channel is approximately 0.4 meters, which differs from the ice thickness measured using resistivity differences by 0.02 meters. The temperature sensor electrode contact spacing is 5 centimeters. By utilizing the differences in resistivity and temperature characteristics of the three media—the river ice layer, the water beneath the ice, and the air—to measure the ice thickness, and combining this with data from a capacitive sensor, the data from the three sensors complement and verify each other, effectively correcting the measured ice thickness results. This makes the measured data more reliable and the system values ​​more stable.

[0046] All parts not disclosed in this invention are prior art, and their specific structures, materials, and working principles will not be described in detail. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for detecting ice layer thickness based on resistive-capacitive inductive sensing technology, characterized in that: The capacitive sensor comprises m parallel strip electrodes arranged in a vertical direction on a same plane of a substrate to form a planar multi-electrode array. m resistance contact pairs, each of which comprises one end of a strip electrode as a contact one and an independent loop point on the substrate at the same horizontal level as the contact one as a contact two. m temperature sensors arranged on the substrate at the same horizontal level corresponding to the m resistance contact pairs. The detection method comprises the following steps: The capacitive detection step: the m parallel strip electrodes are used as the planar multi-electrode capacitive sensor, a controller controls a multiplexing analog switch to sequentially load a sinusoidal alternating excitation signal to a selected excitation electrode and synchronously measure a response voltage signal of each electrode; after the response voltage signal is rectified, filtered and A / D converted, a processor determines the proximity of air, ice or water medium to each electrode according to a predetermined voltage-medium relationship model to obtain first medium interface information. The resistance and temperature detection step: the controller selects a resistance contact pair at different heights through the multiplexing analog switch, i.e. applies a detection signal between the contact one and the contact two and measures the resistance value therebetween; at the same time, temperature data of the temperature sensor at the same height as each selected contact pair are collected; based on the resistance value and the temperature data and according to a predetermined resistance-temperature-medium relationship model, the contact of air, ice or water medium to each contact pair is determined to obtain second medium interface information. The data fusion and thickness calculation step: the first medium interface information and the second medium interface information are comprehensively fused and cross-verified to calculate the ice layer thickness and the water level under the ice.

2. The ice layer thickness detection method based on the RC homochiral induction technology according to claim 1, characterized in that: In the capacitive detection step, the sinusoidal alternating excitation signal is a sinusoidal wave with a peak value of 5V and a frequency of 60KHz.

3. The ice layer thickness detection method based on the RC homochiral induction technology according to claim 1, characterized in that: The strip electrode is a copper foil electrode.

4. The ice layer thickness detection method based on the RC homochiral induction technology according to claim 1, characterized in that: In the capacitive detection step, the controller controls the multiplexing analog switch to sequentially select the excitation electrode from top to bottom or from bottom to top.

5. The ice layer thickness detection method based on the resistance-capacitance homodyne induction technology according to claim 1, characterized in that: In the resistance and temperature detection step, the controller sequentially selects the resistance contact pair from bottom to top.

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