Satellite terminal multi-pin differential water-falling detection device and method based on M6 interface

Abstract

This invention discloses a multi-pin differential water-fall detection device and method for satellite terminals based on the M6 ​​interface, belonging to the technical field of satellite communication terminal equipment. The device includes an M6 interface body, at least two pairs of detection electrodes with different spacings, a differential impedance detection circuit, and a threshold decision unit. The M6 ​​interface has 12 pins (6 on top and 6 on the bottom), from which near-range and far-range detection pairs are selected as detection electrodes. The differential impedance detection circuit simultaneously measures the equivalent impedance of each pin pair and outputs a differential detection signal based on the impedance difference. The threshold decision unit identifies the liquid type and water-fall scenario through multi-threshold comparison. This invention reuses existing M6 interface pins, incurring zero additional sensor cost. Utilizing multi-pin differential impedance measurement, it can distinguish between various liquid types such as seawater, freshwater, and rainwater, as well as various water-fall scenarios such as rain, splashing, and immersion. It features high detection accuracy, low false alarm rate, and fast response speed.

Description

Technical Field

[0001] This invention belongs to the field of detection, specifically relating to a multi-pin differential water-fall detection device and method for satellite terminals based on the M6 ​​interface. Background Technology

[0002] Satellite communication terminals, including Tiantong satellite handheld terminals, Beidou positioning terminals, and low-orbit satellite mobile terminals, are widely used in marine fisheries operations, inland water operations, outdoor exploration, emergency rescue, and military amphibious operations. In these environments, terminal devices frequently face the risk of liquid immersion, such as rain splashes, water spills, or even complete submersion. Therefore, they need reliable water immersion detection mechanisms to promptly trigger waterproof protection, water immersion alarms, or emergency communication functions.

[0003] In existing technologies, water-fall detection solutions mainly include the following categories: The first type is the single-point continuity detection scheme, such as the Type-C interface moisture detection (LPD) technology used in some consumer electronic devices. This type of scheme typically uses the impedance or capacitive reactance change between a single CC pin and ground to determine the presence of liquid. This type of scheme can only output a binary judgment result of "water present" or "water absent", and cannot distinguish between different water source types such as seawater, freshwater, rainwater, and domestic water. This leads to frequent false alarms in scenarios such as rain, limiting its practicality.

[0004] The second type is the mechanical water-sensitive switch detection solution, such as the water-sensitive switch triggering structure used in the water-fall indicator terminal. This type of solution relies on the physical action of the mechanical switch, which has drawbacks such as slow response speed, easy oxidation and failure of the switch, and large size. In addition, it can only detect whether a water-fall event has occurred and does not have the ability to distinguish between different scenarios.

[0005] The third category is dedicated sensor detection solutions, such as independent conductivity sensors, TDS water quality detection electrodes, or humidity sensors. While these solutions can measure water quality parameters, they require additional dedicated sensor components, occupying valuable PCB space within the terminal, increasing BOM costs, and hindering the structural design of miniaturized handheld satellite terminals.

[0006] Furthermore, existing satellite terminal water impact detection technologies lack a solution that can simultaneously meet the three requirements of "zero additional sensor cost," "multiple water quality type identification," and "distinguishing water impact scenarios." Existing technologies either suffer from high false alarm rates due to their limited detection dimensions or have high hardware costs that hinder mass production and widespread adoption.

[0007] Therefore, how to achieve high-precision water drop detection and multi-dimensional water quality and scene recognition without adding dedicated sensor components, using the existing interface structure of satellite terminals, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] The purpose of this invention is to provide a multi-pin differential water-fall detection device and method for satellite terminals based on the M6 ​​interface, so as to solve the problems mentioned in the background art.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A multi-pin differential water-fall detection device for satellite terminals based on the M6 ​​interface, comprising: The M6 ​​interface body has twelve pins in total, with six pins in the upper row and six pins in the lower row. The upper row pins are denoted as U1 to U6, and the lower row pins are denoted as D1 to D6. At least two pairs of pins with different physical spacing are selected from the twelve pins as detection electrode pairs. The at least two pairs of pins include a near-field detection pair and a far-field detection pair. The pin spacing of the near-field detection pair is smaller than the pin spacing of the far-field detection pair. A differential impedance detection circuit, electrically connected to each of the at least two pairs of pins, is used to simultaneously measure the equivalent impedance value between each pin pair and output a differential detection signal characterizing the liquid based on the impedance difference between different pin pairs; and The threshold decision unit is connected to the output of the differential impedance detection circuit and is used to compare the differential detection signal with a preset threshold and output the corresponding water-falling state and liquid type identification result.

[0010] Furthermore, the near-field detection pair consists of one pin in the upper row and an adjacent pin in the corresponding position in the lower row, with a pin spacing of 0.5 mm to 1 mm; the far-field detection pair consists of a pin at one end of the upper row and a pin at the other end of the lower row, with a pin spacing covering the entire length of the M6 ​​interface.

[0011] Furthermore, the differential impedance detection circuit includes an operational amplifier unit, an excitation signal injection circuit, a signal conditioning and filtering circuit, and a protection resistor network; The positive input terminal of the operational amplifier unit is connected to the first detection pin pair through a first resistor network, the negative input terminal is connected to the second detection pin pair through a second resistor network, and the output terminal outputs a voltage signal proportional to the impedance difference between the two pin pairs. The excitation signal injection circuit is used to apply a DC excitation voltage to each detection pin pair, wherein the excitation voltage does not exceed 3.3 volts; The signal conditioning and filtering circuit includes multiple parallel filter capacitors connected between each signal path and ground to filter out high-frequency interference noise. The protection resistor network is connected in series between each detection pin and the operational amplifier input terminal for current limiting protection and voltage division ratio setting.

[0012] Furthermore, the threshold decision unit includes at least two levels of comparator circuits, each of which is set with a different comparison threshold to divide the differential detection signal into multiple impedance intervals. Different impedance intervals correspond to different liquid types and water-falling scenarios.

[0013] Furthermore, the liquid types include seawater, fresh water, tap water, and rainwater; the water-falling scenarios include dry state, rain state, splashing state, partial immersion state, and complete immersion state.

[0014] Furthermore, the detection electrode pair also includes a mid-range detection pair, the pin spacing of which is between that of the near-range detection pair and the far-range detection pair; the near-range detection pair, the mid-range detection pair, and the far-range detection pair together constitute three sets of differential measurement channels.

[0015] A satellite communication terminal includes the aforementioned M6 interface-based multi-pin differential water-fall detection device for satellite terminals.

[0016] A multi-pin differential water-fall detection method for satellite terminals based on the M6 ​​interface includes the following steps: Step S1, Pin Selection Step: Select at least two pairs of pins with different physical spacing from the twelve pins of the M6 ​​interface of the satellite terminal as detection electrode pairs, including at least one pair of close-range pins and one pair of long-range pins. Step S2, Excitation Application Step: Apply a DC excitation voltage of preset amplitude to each detection electrode pair; Step S3, Differential Impedance Acquisition Step: Simultaneously acquire the equivalent impedance values ​​between each detection electrode pair to obtain near-distance impedance data and far-distance impedance data; Step S4, Differential characteristic calculation step: Calculate the differential impedance characteristics of the liquid based on the absolute value and relative ratio of the near-distance impedance data and the far-distance impedance data; Step S5, Threshold matching step: Match the differential impedance characteristics with multiple preset threshold intervals to determine the liquid type and water-falling scenario in the current interface area; Step S6, Result Output Step: Output the corresponding water-fall status signal and water quality identification result, and trigger the corresponding terminal protection or alarm action.

[0017] Further, in step S4, the calculation of the differential impedance characteristics includes: calculating the ratio k = R_near / R_far of the impedance value of the near pin pair to the impedance value of the far pin pair.

[0018] Further, in step S5, the specific rules for scene determination based on differential impedance characteristics are as follows: When R_near is greater than the first high-resistivity threshold and R_far is greater than the second high-resistivity threshold, it is determined to be a dry and anhydrous state. When R_near is in the medium-high resistance range and R_far is in the open circuit range, it is determined to be in a rainy state. When R_near is in the medium resistance range and R_far is in the high resistance range, it is determined to be a splashing state; When R_near is in the low resistance range and R_far is in the medium resistance range, it is determined to be a freshwater immersion state. When R_near is in the extremely low resistance range and R_far is in the low resistance range, it is determined to be a state of seawater immersion.

[0019] Beneficial effects: This invention reuses the existing M6 interface pins of the satellite terminal as detection electrodes, eliminating the need to add dedicated humidity sensors, conductivity sensors or water-sensitive switches, effectively reducing BOM costs and saving internal PCB space in the terminal, making it especially suitable for miniaturized handheld satellite terminals.

[0020] This invention utilizes differential impedance measurement with pin pairs of different spacings to not only detect whether water has fallen into the water, but also to distinguish between various liquid types such as seawater, fresh water, tap water, and rainwater. Furthermore, it can identify different water-falling scenarios such as rain, splashing, partial immersion, and complete immersion, significantly reducing the false alarm rate and enhancing the practical value of the detection. Attached Figure Description

[0021] Figure 1 This is a diagram of the peripheral hardware circuit of the M6 ​​interface body of the present invention. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0023] Combination Figure 1 As shown, this embodiment provides a satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface, including an M6 interface body, two pairs of detection electrode pairs, and a differential impedance detection circuit.

[0024] As shown in the figure, Figure 1The main chip is the connector body (or interface integrated chip) of the M6 ​​interface, with a total of 30 pins. In addition to 12 signal pins arranged in a double row of 6 on top and 6 on the bottom, it also includes power, ground and other functional pins. The water-fall detection electrode pairs (U1~U6, D1~D6) of this invention are selected from the signal pins of this interface and connected to the differential impedance detection circuit in the subsequent stage.

[0025] The M6 ​​interface body adopts a standard 12-pin M6 interface structure, arranged in a double row of 6 pins on top and 6 pins on the bottom. The pins on the top row are numbered U1, U2, U3, U4, U5, and U6 from left to right, and the pins on the bottom row are numbered D1, D2, D3, D4, D5, and D6 from left to right.

[0026] Two pairs of pins with different physical spacings were selected from the above twelve pins as detection electrode pairs: the first pair is a short-range detection pair, consisting of the first pin U1 in the upper row and the first pin D1 in the lower row. This pair of pins is arranged adjacent to each other in the vertical direction with the smallest physical spacing, about 0.8 mm, and is used for high-sensitivity detection of the presence of trace liquids; the second pair is a long-range detection pair, consisting of the sixth pin U6 in the upper row and the first pin D1 in the lower row. This pair of pins spans the diagonal direction of the interface with the largest physical spacing, about 5 mm, and is used for low-sensitivity reference measurement to calculate liquid resistivity.

[0027] The differential impedance detection circuit includes an operational amplifier unit, an excitation signal injection circuit, a signal conditioning and filtering circuit, and a protection resistor network.

[0028] The operational amplifier unit is a rail-to-rail operational amplifier. Its positive input terminal +IN is connected to the first detection pin P1 (corresponding to pin U1) through the first current-limiting resistor R2053, and its negative input terminal -IN is connected to the second detection pin P2 (corresponding to pin D1) through the second current-limiting resistor R2060. The output terminal OUT of the operational amplifier outputs an analog voltage signal that is proportional to the impedance difference between the two pins.

[0029] The excitation signal injection circuit includes a 3.3V DC power supply VCC_IO_3V3 and a bias resistor network. The VCC_IO_3V2 power supply provides DC bias to the positive input of the operational amplifier via a bias resistor R2056 (10kΩ); the VCC_IO_3V3 power supply provides the detection excitation voltage to the detection pin via a current-limiting resistor R2063 (1kΩ). The detection excitation voltage is set to 3.3V, which is within a safe low voltage range and effectively avoids liquid electrolysis effects and electrode polarization problems.

[0030] The signal conditioning and filtering circuit includes multiple filter capacitors C2054, C2055, C2060, C2061, and C2062, each with a capacitance of 100 nanofarads. These capacitors are connected in parallel between each signal path and ground, forming a multi-stage low-pass filter network used to filter out radio frequency interference and environmental noise. The cutoff frequency is approximately 16 kHz.

[0031] The protection resistor network includes current-limiting resistors such as R2053, R2060, R2063, R2058, and R2105. Each current-limiting resistor has a resistance of 1 kΩ and is connected in series between each detection pin and the operational amplifier port. It is used to prevent excessive current from damaging the operational amplifier chip when the interface is short-circuited, and also participates in setting the voltage division ratio of the detection circuit.

[0032] The operational amplifier's output OUT is further filtered by an RC low-pass network consisting of output resistor R2055 (10 kΩ) and filter capacitor C2054, resulting in the output detection signal OUT-1. This OUT-1 signal can be directly connected to the ADC acquisition port of the satellite terminal's main control MCU for digital processing, or it can be connected to a subsequent comparator circuit for hardware threshold determination.

[0033] The equivalent circuit model and the working principle of this embodiment are as follows: When the M6 ​​interface area is dry and waterless, U1 and D1, as well as U6 and D1, are in an air-insulated state, with equivalent impedances greater than 1 megohm. The two input terminals of the operational amplifier are approximately open-circuited, and the output voltage is maintained at the preset reference bias level.

[0034] When liquid enters the M6 ​​interface area, it forms conductive water bridges between the detection pin pairs, generating an equivalent liquid resistance. For the close-range detection pair U1-D1, due to the small pin spacing and short liquid conduction path, the equivalent liquid resistance Rw1 is relatively small. For the long-range detection pair U6-D1, due to the large pin spacing and long liquid conduction path, the equivalent liquid resistance Rw2 is relatively large. According to the law of resistance, assuming uniform liquid resistivity, the ratio of Rw1 to Rw2 is approximately equal to the ratio of the physical spacing between the two pin pairs. This ratio is only related to the resistivity characteristics of the liquid itself and has a low correlation with factors such as the liquid coverage area and liquid film thickness.

[0035] The operational amplifier detects the difference between the two impedances and converts it into a differential voltage output. By simultaneously acquiring the absolute values ​​of the two impedances and calculating their relative ratio, a "fingerprint" characteristic of the liquid resistivity can be established, thereby deducing the type of liquid.

[0036] The resistivity of different types of liquids varies significantly, and the corresponding impedance ranges are as follows: the resistivity of seawater is about 0.2 ohm-meters, corresponding to extremely low impedance for all pin pairs; the resistivity of lake or river water is about 10 to 100 ohm-meters, corresponding to medium impedance; the resistivity of tap water is about 1 to 50 ohm-meters, corresponding to low to medium impedance; the resistivity of clean rainwater is about 100 to 1000 ohm-meters, corresponding to higher impedance; and the resistivity of pure water or distilled water is greater than 1000 ohm-meters, approaching an open circuit state.

[0037] Based on the above impedance characteristics, and combined with the combination of close-range pin pairs and far-range pin pairs, the following scenarios can be distinguished: Dry and anhydrous: The impedance at close range is greater than 1 megohm, and the impedance at long distance is greater than 1 megohm; both paths exceed the upper limit of the high impedance threshold. Rainy weather: The impedance at close range is in the medium to high impedance range, and the impedance at long distance is close to an open circuit, indicating that only a small number of raindrops bridged the nearby pins. When domestic water is splashed: the impedance at close range is in the medium resistance range, and the impedance at long distance is in the high resistance range, indicating that a small amount of liquid has locally wetted the interface area; When exposed to fresh water: the impedance at close range is in the low resistance range, and the impedance at long distance is in the medium resistance range, indicating that a large area of ​​liquid covers the entire interface. When falling into seawater: the impedance at close range is in the extremely low resistance range, and the impedance at long distance is in the low resistance range, indicating that all pin pairs are bridged by a highly conductive liquid. Example 2:

[0038] This embodiment adds a third set of detection electrode pairs to the first embodiment, forming a three-channel differential measurement architecture.

[0039] In addition to the near-range detection pair CH1 (U1-D1) and the far-range detection pair CH3 (U6-D1) described in Example 1, a mid-range detection pair CH2 is added, which is composed of the third pin U3 in the upper row and the fourth pin D4 in the lower row, with their physical spacing between the near-range pair and the far-range pair.

[0040] The three detection channels correspond to near, medium, and far spacing levels, respectively, and each is independently connected to a differential impedance detection branch. The three detection signals are simultaneously sent to the MCU's multi-channel ADC for synchronous acquisition.

[0041] This embodiment utilizes joint analysis of three sets of impedance data with different spacings to construct a more accurate liquid impedance spectrum characteristic curve, further improving the accuracy and anti-interference capability of water quality identification. For example, when the liquid distribution in the interface area is uneven, cross-validation of the three sets of data can effectively eliminate misjudgments caused by local anomalies. Example 3:

[0042] In this embodiment, a three-stage comparator array is cascaded after the output of the operational amplifier in Embodiment 1 to form a fully hardware detection and decision scheme, which does not require the participation of an MCU in the calculation.

[0043] The detection signal OUT-1 is input to the non-inverting input of the three comparators respectively, and the inverting input of the three comparators is connected to different reference voltage thresholds Vth1, Vth2, and Vth3 respectively, where Vth1 < Vth2 < Vth3.

[0044] The threshold Vth1 of the first comparator is set as the threshold for determining whether there is water or not. When OUT-1 is lower than Vth1, it outputs a high level, indicating that liquid is detected. The threshold Vth2 of the second comparator is set as the freshwater / saltwater boundary threshold. When OUT-1 is lower than Vth2, it outputs a high level, indicating that the liquid has a high conductivity and is determined to be saltwater or seawater. The threshold Vth3 of the third comparator is set as the threshold between small and large amounts. When OUT-1 is lower than Vth3, it outputs a high level, indicating that the liquid coverage area is large and is determined to be deep immersion.

[0045] The outputs of the three comparators together form a three-bit binary status code, which can represent up to eight different water-fall scenario states. This coded signal can be directly connected to the terminal's power management chip or alarm circuit to achieve a fast, purely hardware-based response without software intervention, with a response time controllable to within 1 millisecond. Example 4:

[0046] This embodiment provides a multi-pin differential water-fall detection method for satellite terminals based on the M6 ​​interface, specifically including the following steps: Step S1, Pin Selection: From the twelve pins of the M6 ​​interface on the satellite terminal, select U1-D1 as the near-range detection pair and U6-D1 as the long-range detection pair. In the enhanced configuration, U3-D4 can also be selected as the mid-range detection pair. Each detection pin pair is connected to the detection circuit via an analog switch or direct wiring.

[0047] Step S2, Excitation Application Step: The satellite terminal's main control MCU initiates the detection process with a 500-millisecond cycle, controlling the power management unit to apply a 3.3-volt DC excitation voltage to the detection circuit. During non-detection periods, the excitation power supply is cut off to reduce standby power consumption.

[0048] Step S3, Differential Impedance Acquisition Step: The differential impedance detection circuit simultaneously acquires the equivalent impedance value R_near of the near-distance detection pair and the equivalent impedance value R_far of the far-distance detection pair. After being converted into the corresponding analog voltage by the operational amplifier, the voltage is digitally sampled by the 12-bit ADC built into the MCU. The sampling is performed 8 times and the average value is taken to suppress noise.

[0049] Step S4, Differential Feature Calculation Step: The MCU calculates the differential impedance characteristic parameters based on the sampled R_near and R_far values, including the absolute impedance characteristic and the impedance ratio characteristic k = R_near / R_far.

[0050] Step S5, Threshold Matching Step: The MCU performs a lookup match between the calculated differential impedance characteristics and a preset threshold table. The preset threshold table is stored in the MCU's non-volatile memory and contains multiple impedance ranges and their corresponding liquid types and scene labels.

[0051] Step S6, Result Output Step: Output the corresponding control signal based on the identification result. When it is determined that the seawater is completely submerged, trigger the highest level of water ingress alarm and activate the emergency position indication function; when it is determined that freshwater is submerged, trigger the interface waterproof protection mechanism; when it is determined that it is rained or splashed, only record the status and do not trigger an alarm to avoid false alarms.

[0052] In summary This application discloses a multi-pin differential water-fall detection device for satellite terminals based on the M6 ​​interface, which includes: The M6 ​​interface body has twelve pins in total, with six pins in the upper row and six pins in the lower row. The upper row pins are denoted as U1 to U6, and the lower row pins are denoted as D1 to D6. At least two pairs of pins with different physical spacing are selected from the twelve pins as detection electrode pairs. The at least two pairs of pins include a near-field detection pair and a far-field detection pair. The pin spacing of the near-field detection pair is smaller than the pin spacing of the far-field detection pair. A differential impedance detection circuit, electrically connected to each of the at least two pairs of pins, is used to simultaneously measure the equivalent impedance value between each pin pair and output a differential detection signal characterizing the liquid based on the impedance difference between different pin pairs; and The threshold decision unit is connected to the output of the differential impedance detection circuit and is used to compare the differential detection signal with a preset threshold and output the corresponding water-falling state and liquid type identification result.

[0053] Furthermore, the near-field detection pair consists of one pin in the upper row and an adjacent pin in the corresponding position in the lower row, with a pin spacing of 0.5 mm to 1 mm; the far-field detection pair consists of a pin at one end of the upper row and a pin at the other end of the lower row, with a pin spacing covering the entire length of the M6 ​​interface.

[0054] Furthermore, the differential impedance detection circuit includes an operational amplifier unit, an excitation signal injection circuit, a signal conditioning and filtering circuit, and a protection resistor network; The positive input terminal of the operational amplifier unit is connected to the first detection pin pair through a first resistor network, the negative input terminal is connected to the second detection pin pair through a second resistor network, and the output terminal outputs a voltage signal proportional to the impedance difference between the two pin pairs. The excitation signal injection circuit is used to apply a DC excitation voltage to each detection pin pair, wherein the excitation voltage does not exceed 3.3 volts; The signal conditioning and filtering circuit includes multiple parallel filter capacitors connected between each signal path and ground to filter out high-frequency interference noise. The protection resistor network is connected in series between each detection pin and the operational amplifier input terminal for current limiting protection and voltage division ratio setting.

[0055] Furthermore, the threshold decision unit includes at least two levels of comparator circuits, each of which is set with a different comparison threshold to divide the differential detection signal into multiple impedance intervals. Different impedance intervals correspond to different liquid types and water-falling scenarios.

[0056] Furthermore, the liquid types include seawater, fresh water, tap water, and rainwater; the water-falling scenarios include dry state, rain state, splashing state, partial immersion state, and complete immersion state.

[0057] Furthermore, the detection electrode pair also includes a mid-range detection pair, the pin spacing of which is between that of the near-range detection pair and the far-range detection pair; the near-range detection pair, the mid-range detection pair, and the far-range detection pair together constitute three sets of differential measurement channels.

[0058] In addition, this application discloses a satellite communication terminal, which includes the aforementioned satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface.

[0059] In addition, this application discloses a multi-pin differential water-fall detection method for satellite terminals based on the M6 ​​interface, which includes the following steps: Step S1, Pin Selection Step: Select at least two pairs of pins with different physical spacing from the twelve pins of the M6 ​​interface of the satellite terminal as detection electrode pairs, including at least one pair of close-range pins and one pair of long-range pins. Step S2, Excitation Application Step: Apply a DC excitation voltage of preset amplitude to each detection electrode pair; Step S3, Differential Impedance Acquisition Step: Simultaneously acquire the equivalent impedance values ​​between each detection electrode pair to obtain near-distance impedance data and far-distance impedance data; Step S4, Differential characteristic calculation step: Calculate the differential impedance characteristics of the liquid based on the absolute value and relative ratio of the near-distance impedance data and the far-distance impedance data; Step S5, Threshold matching step: Match the differential impedance characteristics with multiple preset threshold intervals to determine the liquid type and water-falling scenario in the current interface area; Step S6, Result Output Step: Output the corresponding water-fall status signal and water quality identification result, and trigger the corresponding terminal protection or alarm action.

[0060] Further, in step S4, the calculation of the differential impedance characteristics includes: calculating the ratio k = R_near / R_far of the impedance value of the near pin pair to the impedance value of the far pin pair.

[0061] Further, in step S5, the specific rules for scene determination based on differential impedance characteristics are as follows: When R_near is greater than the first high-resistivity threshold and R_far is greater than the second high-resistivity threshold, it is determined to be a dry and anhydrous state. When R_near is in the medium-high resistance range and R_far is in the open circuit range, it is determined to be in a rainy state. When R_near is in the medium resistance range and R_far is in the high resistance range, it is determined to be a splashing state; When R_near is in the low resistance range and R_far is in the medium resistance range, it is determined to be a freshwater immersion state. When R_near is in the extremely low resistance range and R_far is in the low resistance range, it is determined to be a state of seawater immersion.

Claims

1. A multi-pin differential water-fall detection device for satellite terminals based on the M6 ​​interface, characterized in that, include: The M6 ​​interface body has twelve pins in total, with six pins in the upper row and six pins in the lower row. The upper row pins are denoted as U1 to U6, and the lower row pins are denoted as D1 to D6. At least two pairs of pins with different physical spacing are selected from the twelve pins as detection electrode pairs. The at least two pairs of pins include a near-field detection pair and a far-field detection pair. The pin spacing of the near-field detection pair is smaller than the pin spacing of the far-field detection pair. A differential impedance detection circuit is electrically connected to the at least two pairs of pins respectively, and is used to simultaneously measure the equivalent impedance value between each pair of pins, and output a differential detection signal characterizing the liquid characteristics based on the impedance difference of different pairs of pins. as well as The threshold decision unit is connected to the output of the differential impedance detection circuit and is used to compare the differential detection signal with a preset threshold and output the corresponding water-falling state and liquid type identification result.

2. The satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface according to claim 1, characterized in that, The near-field detection pair consists of one pin in the upper row and an adjacent pin in the corresponding position in the lower row, with a pin spacing of 0.5 mm to 1 mm; the far-field detection pair consists of a pin at one end of the upper row and a pin at the other end of the lower row, with a pin spacing covering the entire length of the M6 ​​interface.

3. The satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface according to claim 1, characterized in that, The differential impedance detection circuit includes an operational amplifier unit, an excitation signal injection circuit, a signal conditioning and filtering circuit, and a protection resistor network. The positive input terminal of the operational amplifier unit is connected to the first detection pin pair through a first resistor network, the negative input terminal is connected to the second detection pin pair through a second resistor network, and the output terminal outputs a voltage signal proportional to the impedance difference between the two pin pairs. The excitation signal injection circuit is used to apply a DC excitation voltage to each detection pin pair, wherein the excitation voltage does not exceed 3.3 volts; The signal conditioning and filtering circuit includes multiple parallel filter capacitors connected between each signal path and ground to filter out high-frequency interference noise. The protection resistor network is connected in series between each detection pin and the operational amplifier input terminal for current limiting protection and voltage division ratio setting.

4. The satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface according to claim 3, characterized in that, The threshold decision unit includes at least two levels of comparator circuits. Each level of comparator is set with a different comparison threshold to divide the differential detection signal into multiple impedance intervals. Different impedance intervals correspond to different liquid types and water-falling scenarios.

5. The satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface according to claim 1, characterized in that, The liquid types include seawater, fresh water, tap water, and rainwater; the water-falling scenarios include dry state, rain state, splashing state, partial immersion state, and complete immersion state.

6. The satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface according to claim 1, characterized in that, The detection electrode pair also includes a mid-range detection pair, the pin spacing of which is between that of the near-range detection pair and the far-range detection pair; the near-range detection pair, the mid-range detection pair, and the far-range detection pair together constitute three sets of differential measurement channels.

7. A satellite communication terminal, characterized in that, Includes the satellite terminal multi-pin differential water-fall detection device based on the M6 ​​interface as described in any one of claims 1 to 6.

8. A multi-pin differential water-fall detection method for satellite terminals based on the M6 ​​interface, characterized in that, Includes the following steps: Step S1, Pin Selection Step: Select at least two pairs of pins with different physical spacing from the twelve pins of the M6 ​​interface of the satellite terminal as detection electrode pairs, including at least one pair of close-range pins and one pair of long-range pins. Step S2, Excitation Application Step: Apply a DC excitation voltage of preset amplitude to each detection electrode pair; Step S3, Differential Impedance Acquisition Step: Simultaneously acquire the equivalent impedance values ​​between each detection electrode pair to obtain near-distance impedance data and far-distance impedance data; Step S4, Differential characteristic calculation step: Calculate the differential impedance characteristics of the liquid based on the absolute value and relative ratio of the near-distance impedance data and the far-distance impedance data; Step S5, Threshold matching step: Match the differential impedance characteristics with multiple preset threshold intervals to determine the liquid type and water-falling scenario in the current interface area; Step S6, Result Output Step: Output the corresponding water-fall status signal and water quality identification result, and trigger the corresponding terminal protection or alarm action.

9. The multi-pin differential water-fall detection method for satellite terminals based on the M6 ​​interface according to claim 8, characterized in that, In step S4, the calculation of the differential impedance characteristics includes: calculating the ratio k = R_near / R_far of the impedance value of the near pin pair to the impedance value of the far pin pair.

10. The multi-pin differential water-fall detection method for satellite terminals based on the M6 ​​interface according to claim 8, characterized in that, In step S5, the specific rules for scene determination based on differential impedance characteristics are as follows: When R_near is greater than the first high-resistivity threshold and R_far is greater than the second high-resistivity threshold, it is determined to be a dry and anhydrous state. When R_near is in the medium-high resistance range and R_far is in the open circuit range, it is determined to be in a rainy state. When R_near is in the medium resistance range and R_far is in the high resistance range, it is determined to be a splashing state; When R_near is in the low resistance range and R_far is in the medium resistance range, it is determined to be a freshwater immersion state. When R_near is in the extremely low resistance range and R_far is in the low resistance range, it is determined to be a state of seawater immersion.

Images