Underwater robot detection method and system based on array coil

Abstract

The application discloses an underwater robot detection method and system based on arrayed coils, belongs to the technical field of wireless power transmission system detection, and combines multiple detection coils to form an arrayed detection coil group, at least two arrayed detection coil groups are arranged at predetermined positions along a preset motion track of an underwater robot, an impedance change detection circuit is connected to each detection coil, the position of the underwater robot relative to the coils can be determined by using the double arrayed detection coils, different diameters of different models of the underwater robot can be distinguished, whether the underwater robot deviates can be monitored, the speed of the underwater robot at the moment can be determined, the pose of the underwater robot can be better adjusted, the measurement error can be better reduced by uniform arrangement and symmetrical distribution, the underwater robot can safely and stably enter the charging device, and the charging device and the underwater robot are prevented from being damaged.

Description

Technical Field

[0001] This invention belongs to the field of wireless power transmission system detection technology, and more specifically, relates to an underwater robot detection method and system based on arrayed coils. Background Technology

[0002] Underwater robots are playing an increasingly important role in scientific experiments, marine surveys, and commercial applications, and can perform a variety of complex underwater tasks. Therefore, charging UUVs to ensure their sustainable operation is crucial. Using wireless power transfer technology to charge underwater robots overcomes the drawbacks of traditional plug-in charging. However, before charging, the underwater robot needs to enter a "barrel-type" charging system. The system requires monitoring the robot's position and speed upon entry to better control its safe, stable, and accurate arrival at the charging point for fixed charging.

[0003] Currently, the main technologies for position and velocity detection of underwater robots include: acoustic detection, visual detection, satellite positioning, inertial navigation, and Earth-matching positioning. Among these, acoustic detection is not accurate enough at very close ranges and requires calibration of complex acoustic beacon networks; in the deep-sea environment, the light is too dim, causing blurred vision and making visual detection inaccurate; similarly, satellite positioning and Earth-matching positioning cannot achieve short-range, small-scale position and velocity detection of underwater robots in the deep-sea environment; inertial navigation is expensive, bulky, and energy-intensive, and the internal gyroscopes and accelerometers have inherent drift errors, which may lead to inaccurate detection. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an underwater robot detection method and system based on arrayed coils. Detection coils are arranged at predetermined intervals, and each detection coil is composed of multiple sub-coils in an array. The position, speed, and model of the underwater robot are determined by the impedance change caused by the underwater robot passing through the detection coils. For the wireless charging system of the underwater robot, the corresponding charging power can be configured according to the model of the device. At the same time, the position and speed of the underwater robot can be controlled to ensure that it safely and stably reaches the charging end for charging, thereby solving the technical problems in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an underwater robot detection method based on an arrayed coil, the key of which includes the following steps:

[0006] S1: At least two array-type detection coil groups are set at predetermined positions along the preset motion trajectory of the underwater robot. Each array-type detection coil group includes multiple detection coils distributed in a ring array. Each detection coil is connected to an impedance change detection circuit.

[0007] S2: The position and / or velocity of the underwater robot are determined by recording the impedance change of at least a portion of the detection coils in at least two arrayed detection coil groups as the underwater robot approaches, using the impedance transformation detection circuit.

[0008] As a preferred embodiment of the present invention, the method further includes the following steps:

[0009] S3: The impedance transformation detection circuit records the impedance change of at least a portion of the detection coils in at least one of the arrayed detection coil groups as the underwater robot approaches to determine the offset of the underwater robot relative to the preset motion trajectory and / or the size of the underwater robot model.

[0010] As a preferred technical solution of the present invention, in step S1, a first array-type detection coil group and a second array-type detection coil group are set, and the first array-type detection coil group and the second array-type detection coil group are arranged relative to each other at a predetermined distance s.

[0011] As a preferred embodiment of the present invention, both the first array-type detection coil group and the second array-type detection coil group are hollow ring structures. The movement trajectory of the underwater robot is set along the central axis of the first array-type detection coil group and the second array-type detection coil group, and moves within the annular hollow region of the first array-type detection coil group and the second array-type detection coil group.

[0012] As a preferred technical solution of the present invention, the detection coils are all made of Litz wire wound into a rectangle and bent along the annular arc surface, and multiple detection coils in the same array detection coil group are arranged at equal intervals.

[0013] As a preferred technical solution of the present invention, when the underwater robot moves to the position of one of the array-type detection coil groups, the offset of the underwater robot relative to the preset motion trajectory is determined by multiple detection coils in the current array-type detection coil group.

[0014] As a preferred embodiment of the present invention, the impedance change detection circuit includes a high-frequency AC signal loading circuit and a voltage detection circuit. The voltage detection circuit determines the time when the impedance change caused by the underwater robot approaching the detection coil reaches a preset threshold. The position and / or speed of the underwater robot are determined by the travel distance between the at least two array-type detection coil groups and the time it takes for the underwater robot to approach a corresponding array-type detection coil group.

[0015] As a preferred embodiment of the present invention, the voltage detection circuit includes a voltage amplitude detection circuit and a voltage phase detection circuit.

[0016] To facilitate the implementation of an underwater robot detection method based on arrayed coils, this invention also provides an underwater robot detection system based on arrayed coils, comprising at least two arrayed detection coil groups set at predetermined positions along a preset motion trajectory of the underwater robot. Each arrayed detection coil group includes multiple detection coils distributed in a ring array, and each detection coil is connected to an impedance change detection circuit. The impedance change detection circuit records the impedance change of at least a portion of the detection coils in at least two arrayed detection coil groups as the underwater robot approaches to determine the position and / or velocity and / or offset of the underwater robot.

[0017] As a preferred embodiment of the present invention, the array-type detection coil group is disposed on the guide device of the fixed charging base station, and the guide device is provided with a fixing buckle device.

[0018] This invention provides an underwater robot detection method and system based on arrayed coils, which has the following features:

[0019] Beneficial effects:

[0020] 1. Using a dual-array detection coil, the position of the underwater robot relative to the coil can be determined, different models and diameters of underwater robots can be identified, and the robot's deviation can be monitored. Simultaneously, the robot's speed can be determined to better adjust its posture. Furthermore, the uniform and symmetrical distribution of the coils can better reduce measurement errors, ensuring the underwater robot safely and stably enters the charging device, avoiding damage to both the charging device and the underwater robot.

[0021] 2. The detection is based on the principle that the presence of metal around the coil generates an eddy current effect, which changes the coil impedance. It is unaffected by external environments such as light, sound, or underwater, and has the advantage of strong adaptability.

[0022] 3. The coil has a simple structure, small size, strong stability, and low production cost, which is conducive to implementation and promotion. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the underwater robot entering a fixed charging base station according to this embodiment;

[0024] Figure 2 This is a schematic diagram of the structure of the array-type detection coil group provided in this embodiment;

[0025] Figure 3 This is the equivalent circuit diagram of a metal in a magnetic field provided in this embodiment;

[0026] Figure 4 This is a flowchart of the underwater robot position and velocity detection provided in this embodiment;

[0027] Figure 5 This is a three-dimensional structural diagram of the underwater robot with a diameter of 80cm during inspection, provided in this embodiment.

[0028] Figure 6 This is a front view of the structure of an 80cm diameter underwater robot during inspection, as provided in this embodiment.

[0029] Figure 7 This is a three-dimensional structural diagram of the underwater robot with a diameter of 54cm during inspection, provided in this embodiment.

[0030] Figure 8 This is a frontal view of the structure of the 54cm diameter underwater robot during inspection, as provided in this embodiment.

[0031] Figure 9 This is a three-dimensional structural diagram of the underwater robot displacement detection provided in this embodiment;

[0032] Figure 10 This is a frontal view of the structure for detecting underwater robot displacement provided in this embodiment.

[0033] Figure 11 This is a graph showing the change in the real part of the impedance of an 80cm diameter underwater robot as it passes by, as provided in this embodiment.

[0034] Figure 12 The diagram shows the change in the real part of the impedance when an underwater robot with a diameter of 80cm and an underwater robot with a diameter of 54cm passes by, as provided in this embodiment.

[0035] Figure 13 The diagram shows the change in the real part of the impedance of the underwater robot when it passes by with a displacement of 18cm, as provided in this embodiment.

[0036] In the diagram: 11. First array-type detection coil group; 12. Second array-type detection coil group; 2. Underwater robot; 3. Fixed charging system; 31. Guiding device; 32. Fixing buckle device; A. Coil A; B. Coil B. Detailed Implementation

[0037] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0038] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] Please see Figure 1 and Figure 2 The present invention provides a technical solution: an underwater robot detection method and system based on arrayed coils, comprising setting at least two arrayed detection coil groups at predetermined positions along a preset motion trajectory of an underwater robot 2, each arrayed detection coil group comprising multiple detection coils distributed in a ring array, each detection coil being connected to an impedance change detection circuit, the impedance change detection circuit recording the impedance change of at least a portion of the detection coils in the at least two arrayed detection coil groups as the underwater robot 2 approaches to determine the position and / or velocity and / or offset of the underwater robot;

[0041] The array-type detection coil group is set on the guide device 31 of the fixed charging base station 3, and the guide device 31 is provided with a fixing buckle device 32.

[0042] The underwater robot 2 contains a large number of metal objects. When it enters an alternating magnetic field, due to the eddy current effect, it can be equivalent to a circuit with an inductor and a resistor connected in series, thus coupling with the detection coil. When the underwater robot 2 is not present, [the following text is incomplete and likely refers to a separate process:] ...by... Figure 3 The impedance of the detection coil is known to be:

[0043] Z0 = R s +jωL s

[0044] According to Kirchhoff's law, when underwater robot 2 appears near the energized coil, a voltage balance equation can be obtained:

[0045]

[0046] Therefore, when underwater robot 2 is present, the equivalent impedance of the detection coil is:

[0047]

[0048] Similarly, since seawater contains a relatively high amount of salt, with a salinity between 3.2% and 3.8%, an electrical conductivity of 4.45-4.81 S / m, and a relative permittivity of 81, when a high-frequency electromagnetic field is applied to the detection coil, the seawater environment will also generate an eddy current effect based on the same principle.

[0049] Therefore, in seawater, when underwater robot 2 is present, the equivalent impedance of the detection coil is:

[0050]

[0051] In seawater, when the metal part inside the underwater robot 2 is greater than the air part, the real part of the coil's impedance will increase; if the metal part is less than the air part, the real part of the coil's impedance will decrease.

[0052] If other non-metallic objects appear in the seawater, the equivalent impedance of the detection coil becomes extremely small due to the reduction of eddy current effect, and cannot trigger the detection threshold, so it can be ignored.

[0053] Furthermore, the equivalent impedance of the detection coil will be different depending on the position of the underwater robot 2 at the detection coil.

[0054] Based on the above principles, the position and velocity of the underwater robot 2 can be detected by monitoring changes in the impedance of the detection coil. The specific process is as follows: Figure 4 As shown.

[0055] Once underwater robot 2 enters the fixed charging station, its position and speed are detected by an array of detection coils. This information is used to adjust the robot's posture to ensure it reaches the charging device more effectively and is properly secured for charging. This prevents the robot from colliding with the fixed charging system at excessive speed and damaging the charging device.

[0056] Adjusting the pose involves the following steps:

[0057] Step 1: The closer the underwater robot 2 is to the detection coil, the smaller the real part of its detection coil impedance. By comparing the real part of the impedance of the detection coils in the same array detection coil group, the offset of the underwater robot 2 in the array detection coil group can be determined.

[0058] Step 2: Send a signal to the underwater robot 2 to move away from the direction with relatively small impedance of the array detection coil in the plane direction. When the impedance of the two detection coils at symmetrical positions is the same and the impedance is small relative to other coils, move the underwater robot 2 away from the two detection coils at the same distance.

[0059] Step 3: The underwater robot 2 moves along the plane of the array detection coils and stops when the impedance of each detection coil in the array detection coil group is basically the same.

[0060] This embodiment provides a detection method for underwater robots based on arrayed coils, specifically including the following steps:

[0061] S1: Set at least two array-type detection coil groups at predetermined positions along the preset motion trajectory of the underwater robot 2. Each array-type detection coil group includes multiple detection coils distributed in a ring array, and each detection coil is connected to an impedance change detection circuit.

[0062] S2: The position and / or velocity of the underwater robot 2 are determined by recording the impedance change of at least a portion of the detection coils in at least two arrayed detection coil groups as the underwater robot 2 approaches, using an impedance transformation detection circuit.

[0063] This also includes the following steps:

[0064] S3: Determine the offset of the underwater robot 2 relative to the preset motion trajectory and / or the size of the underwater robot 2 by recording the impedance change of at least a portion of the detection coils in at least one array of detection coils as the underwater robot 2 approaches, through the impedance transformation detection circuit.

[0065] Specifically, the closer the underwater robot 2 is to the detection coil, the smaller the real part of its detection coil impedance. By comparing the real part of the detection coil impedance in the same array of detection coils, the offset of the underwater robot 2 in the array of detection coils can be determined.

[0066] At the same position, the larger the diameter of the underwater robot 2, the smaller the real part of its detection coil impedance, and the greater the decreasing trend. The impedance values ​​of underwater robots 2 with different diameters passing through the detection coil are recorded and formed into a database. By comparing the current detection coil impedance with the database, the size of the underwater robot 2 at this time can be determined.

[0067] In step S1, a first array-type detection coil group 11 and a second array-type detection coil group 12 are set up, and the first array-type detection coil group 11 and the second array-type detection coil group 12 are set relative to each other according to a predetermined interval s;

[0068] The first array-type detection coil group 11 and the second array-type detection coil group 12 are both hollow ring structures. The movement trajectory of the underwater robot 2 is set along the central axis of the first array-type detection coil group 11 and the second array-type detection coil group 12, and moves in the annular hollow area of ​​the first array-type detection coil group 11 and the second array-type detection coil group 12.

[0069] The detection coils are all made of Litz wire wound into rectangles and bent along the annular arc surface. Multiple detection coils in the same array of detection coils are arranged at equal intervals.

[0070] When the underwater robot moves to the position of one of the array-type detection coil groups, the offset of the underwater robot relative to the preset motion trajectory is determined by multiple detection coils in the current array-type detection coil group.

[0071] The impedance change detection circuit includes a high-frequency AC signal loading circuit and a voltage detection circuit. In specific implementations, it is usually also equipped with a power supply circuit, an amplifier circuit, a filter circuit and a control circuit. The voltage detection circuit determines the time when the impedance change caused by the underwater robot 2 approaching the detection coil reaches a preset threshold. The position and / or speed of the underwater robot 2 are determined by the travel distance between at least two array-type detection coil groups and the time when the underwater robot 2 approaches the corresponding array-type detection coil group.

[0072] The voltage detection circuit includes a voltage amplitude detection circuit and a voltage phase detection circuit.

[0073] To provide a more intuitive understanding, a simulation experiment will be used for a more vivid illustration:

[0074] like Figure 5 Figure 6 As shown, a simulation is performed using an 80cm diameter underwater robot 2 shell (10mm aluminum alloy shell), a 1m diameter, and a 4MHz frequency detection coil as an example. The simulation process considers the influence of metal and seawater environment on the detection coil. The coil is made of 2mm Litz wire wound along the "barrel-shaped" charging base station shell. Each detection coil is rectangular. Taking eight coils as an example, each detection coil is at a 30° angle relative to the center point, and the spacing between each coil is 15°. They are evenly arranged to form an array of detection coils. Each detection coil is 30mm wide and has 3 turns. The distance between two arrays of detection coils is 20mm.

[0075] Taking a detection coil as an example, when the underwater robot 2 enters the charging device, the underwater robot 2 and the detection coil are considered as a whole. At this time, the original state is disrupted, and the magnetic flux through the detection coil will change. The impedance change of the detection coil is very obvious at this time. The impedance information of the detection coil is extracted and converted into a voltage signal, thereby determining the position of the underwater robot 2. By placing two array-type detection coil groups, the speed of the underwater robot 2 when passing through the two coils can be known. Because the array-type coils are evenly arranged, the deviation of the underwater robot 2 can be detected.

[0076] Taking the detection coil of an 80cm diameter underwater robot at a frequency of 2.4MHz as an example, with impedance change as the observation point, each coil of the arrayed coil is evenly distributed, and the impedance change of the detection coil on one arrayed coil is basically the same. Taking the corresponding coils at the same position on two arrayed coils as examples (the first coil and the second coil respectively), the following table is obtained.

[0077] Table 180cm underwater robot 2 impedance change during transit.

[0078] Position / mm First coil impedance / Ω Second coil impedance / Ω 0 0.047931+7.407384i 0.047934+7.461716i 20 0.047857+7.414258i 0.047905+7.474339i 40 0.047778+7.416092i 0.047851+7.459277i 60 0.047668+7.414056i 0.047793+7.453991i 80 0.047565+7.414350i 0.047702+7.466195i 100 0.047412+7.414893i 0.047609+7.466375i 120 0.047278+7.405602i 0.047615+7.458196i

[0079] When only considering the seawater environment and assuming no underwater robot is present, the coil impedance is 0.430477 + 67.975113i. Since the underwater robot in this example has only a 10mm aluminum shell and its interior is filled with air, the air portion of the underwater robot is much larger than the aluminum portion. Therefore, the change between the real and imaginary parts of the impedance is very significant; the real part of the impedance will be smaller than in seawater and will gradually decrease with distance. (See Table 1 and...) Figure 11 As shown, at position 40, underwater robot 2 passes the first array of detection coils; at position 80, it passes the second array of detection coils. Simulation results show that the impedance change of underwater robot 2 is significant when it passes and does not appear, with a change rate of nearly 88% between the real and imaginary parts. Furthermore, the real part of the coil impedance changes significantly at different positions. As the underwater robot continues to move forward, the real part of the coil impedance gradually decreases, with a change of approximately 0.1 mΩ at different positions. With a 10 mA current applied, the impedance of the detection coils is represented by a voltage signal, and the impedance change is reflected by the voltage change, showing a change of 1 mV. Therefore, the position of underwater robot 2 can be determined based on the voltage amplitude and phase of the two detection coils. Since the distance s between the detection coils remains constant, the velocity V = s / t of underwater robot 2 at this point can be obtained from the time difference t of the voltage change from 40 to 80 mm.

[0080] like Figure 7 Figure 8As shown in the figure, the underwater robot 2 with a diameter of 80cm was replaced with an underwater robot 2 with a diameter of 54cm for comparison simulation. The results are shown in the table below.

[0081] Table 2. Impedance Changes of Underwater Robot 2 with a Diameter of 280cm and a Diameter of 54cm as it Passes By.

[0082] Position / mm Coil impedance at 80cm / Ω 54cm coil impedance / Ω 0 0.047931+7.407384i 0.048139+7.410635i 20 0.047857+7.414258i 0.048158+7.418560i 40 0.047778+7.416092i 0.048113+7.416775i 60 0.047668+7.414056i 0.048070+7.413281i 80 0.047565+7.414350i 0.048133+7.420479i 100 0.047412+7.414893i 0.048082+7.414929i 120 0.047278+7.405602i 0.048072+7.411089i

[0083] As shown in Table 2, when the 54cm underwater robot 2 passes through the detection coil, its position and velocity can also be measured by impedance changes. Furthermore, as shown in Table 2 and... Figure 12 It can be seen that the change in the real part of the impedance of the detection coil is different when the underwater robot 2 passes by at 54cm compared to when it passes by at 80cm. When the underwater robot passes by at 80cm, the real part of the impedance gradually decreases, while when the underwater robot passes by at 54cm, the real part of the impedance remains basically unchanged. Therefore, it can be concluded that this technology can not only detect the position and speed of the underwater robot 2, but also determine the model and size of the underwater robot 2 through detection.

[0084] like Figure 9 Figure 10 As shown, a simulation was conducted by offsetting the 54cm diameter underwater robot 2 by a certain distance. Taking an offset of 18cm from the center position as an example, the underwater robot 2 was offset 18cm towards coil A, which means moving away from coil B. The impedance changes of coil A and coil B were compared, as shown in Table 3.

[0085] From Table 3 and Figure 13 It can be seen that after the position shift, the impedance of coil A and the impedance of coil B differ by at least 1 mΩ when the underwater robot 2 is in the same position. For coil A, the difference is approximately 0.3 mΩ depending on the position. Furthermore, the real part of the impedance of coil A decreases continuously as the underwater robot moves forward, while the real part of the impedance of coil B remains essentially unchanged. Therefore, the position of the underwater robot 2 relative to the coil can be detected based on the impedance change, and the speed of the underwater robot 2 can also be obtained. Moreover, the coil impedance and its change are significantly different when the underwater robot 2 is directly facing the coil compared to when it is shifted. Therefore, it is also possible to detect whether the underwater robot 2 is entering the charging device in a directly facing state, ensuring safe and stable charging.

[0086] Table 3 Impedance variation of underwater robot 2's position offset

[0087] Position / mm Coil A impedance / Ω Coil B impedance / Ω 0 0.047019+7.418168i 0.047935+7.464685i 20 0.046740+7.411291i 0.047991+7.461061i 40 0.046393+7.413069i 0.047914+7.462313i 60 0.046058+7.417979i 0.048012+7.465441i 80 0.045506+7.408590i 0.047980+7.462274i 100 0.044868+7.412163i 0.047940+7.464343i 120 0.044017+7.414280i 0.047970+7.454192i

[0088] This simulation, incorporating the 10mm metal shell of underwater robot 2 and a seawater environment, yields significantly different signals, allowing for the measurement of underwater robot 2's position and velocity. In reality, underwater robot 2 contains numerous metal objects, which would cause even more pronounced impedance changes in the coils, resulting in a further improvement in performance.

[0089] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An array coil-based underwater robot detection method, characterized by, The method comprises the following steps: S1: setting at least two arrayed detection coil groups at predetermined positions along a preset motion trajectory of the underwater robot (2), each of the arrayed detection coil groups comprising a plurality of detection coils arranged in a ring array, each of the detection coils being connected with an impedance change detection circuit; S2: determining the position and / or speed of the underwater robot (2) by recording the impedance change amount of at least some of the detection coils in at least two of the arrayed detection coil groups caused by the proximity of the underwater robot (2) through the impedance change detection circuit.

2. The array coil-based underwater robot detection method of claim 1, wherein, The method further comprises the following step: S3: determining the offset amount of the underwater robot (2) relative to the preset motion trajectory and / or the size of the underwater robot (2) by recording the impedance change amount of at least some of the detection coils in at least one of the arrayed detection coil groups caused by the proximity of the underwater robot (2) through the impedance change detection circuit.

3. The array coil-based underwater robot detection method according to claim 1 or 2, characterized in that: In step S1, a first arrayed detection coil group (11) and a second arrayed detection coil group (12) are set, and the first arrayed detection coil group (11) and the second arrayed detection coil group (12) are oppositely arranged at a predetermined interval s.

4. The array coil-based underwater robot detection method of claim 3, wherein: The first arrayed detection coil group (11) and the second arrayed detection coil group (12) are both hollow ring structures, the motion trajectory of the underwater robot (2) is arranged along the central axes of the first arrayed detection coil group (11) and the second arrayed detection coil group (12), and the underwater robot (2) moves in the ring-shaped hollow regions of the first arrayed detection coil group (11) and the second arrayed detection coil group (12).

5. The array coil based AUV detection method of claim 3, wherein: Each of the detection coils is wound into a rectangle by using a Litz wire and is bent along a ring-shaped arc surface, and the plurality of detection coils in the same arrayed detection coil group are arranged at equal intervals.

6. The array coil based underwater robot detection method of claim 5, wherein: When the underwater robot moves to the position of one of the arrayed detection coil groups, the offset amount of the underwater robot relative to the preset motion trajectory is determined by using the plurality of detection coils in the current arrayed detection coil group.

7. The array coil based underwater robot detection method according to claim 1 or 4 or 5 or 6, characterized in that: The impedance change detection circuit comprises a high-frequency alternating current signal loading circuit and a voltage detection circuit, the occurrence time of the impedance change caused by the proximity of the underwater robot (2) to the detection coil reaching a preset threshold is determined through the voltage detection circuit, and the position and / or speed of the underwater robot (2) are determined by the distance between the at least two arrayed detection coil groups and the time of the proximity of the underwater robot (2) to the corresponding arrayed detection coil group.

8. The array coil based underwater robot detection method of claim 7, wherein: The voltage detection circuit comprises a voltage amplitude detection circuit and a voltage phase detection circuit.

9. An array coil based underwater robot detection system for implementing the array coil based underwater robot detection method of any one of claims 1-8, characterized in that: The method comprises setting at least two arrayed detection coil groups at predetermined positions along a preset motion trajectory of the underwater robot (2), each of the arrayed detection coil groups comprising a plurality of detection coils arranged in a ring array, each of the detection coils being connected with an impedance change detection circuit, and determining the position and / or speed and / or offset amount of the underwater robot by recording the impedance change amount of at least some of the detection coils in at least two of the arrayed detection coil groups caused by the proximity of the underwater robot (2) through the impedance change detection circuit.

10. The array coil based underwater robot detection system of claim 9, wherein: The arrayed detection coil group is arranged on a guide device (31) of the fixed charging system (3), and the guide device (31) is provided with a fixed buckle device (32).

Images