Pre-embedded sensor wireless power supply system receiving end and reinforcing mesh positioning device and method

Abstract

The invention belongs to the technical field of wireless electric energy transmission, discloses a pre-embedded sensor wireless power supply system receiving end and reinforcing mesh positioning device and method, and aims to solve the problems that existing reinforcing bar scanning equipment cannot distinguish common reinforcing bar nodes and receiving ends, and electromagnetic positioning is seriously interfered by reinforcing bar eddy current. The device is composed of a direct current power supply, an inverter, a primary side LCC compensation network, an excitation coil, a decoupling transformer and a four-quadrant detection coil. The inverter is connected with the primary side LCC compensation network; the primary side LCC compensation network is connected with the excitation coil and the primary side winding of the decoupling transformer; the four-quadrant detection coil is connected with a secondary winding of the decoupling transformer and comprises four sub-coils, and the sub-coils at the diagonal positions are reversely connected in series to form a detection loop. Exciting an induced eddy current of a reinforcement network in concrete by using an exciting coil, and obtaining primary and secondary detection voltage effective values through a detection loop; and the mobile detection end monitors voltage change, and when the primary detection voltage and the secondary detection voltage simultaneously reach the maximum value, the position is the accurate position of the receiving end.

Description

A receiver and a steel mesh positioning device and method for a pre-embedded sensor wireless power supply system Technical Field

[0001] This invention belongs to the field of wireless power transmission technology, and provides a receiver for a pre-embedded sensor wireless power supply system and a rebar mesh positioning device and method. Background Technology

[0002] With the rapid development of large-scale infrastructure construction, the health monitoring of concrete structures is crucial for ensuring project safety. Embedding sensors inside the concrete structure is an effective means of obtaining structural condition information, and wireless power transmission technology provides an ideal solution to problems such as limited battery life of embedded sensors and difficulties in deploying power cables.

[0003] However, in practical engineering applications, concrete pouring presents significant positioning challenges. Sensors and their energy receivers are typically fixed to a steel reinforcement network, and once the concrete is poured, all equipment is covered and concealed. Although construction drawings can provide a general installation area, factors such as construction deviations make it impossible to determine the precise coordinates of the energy receiver. If the primary transmitter cannot achieve precise alignment with the receiver within the concrete, coupling efficiency will drop sharply, and effective energy transmission may even be impossible.

[0004] Existing coil positioning technologies are mostly applied to air or environments without metal interference, typically neglecting the presence of dense rebar networks. Rebar, as a good conductor, generates strong induced eddy currents under high-frequency magnetic fields, severely interfering with electromagnetic positioning signals. Furthermore, while existing mature detection equipment such as rebar scanners can effectively detect the distribution of internal rebar, they cannot effectively distinguish and identify the receiver of the pre-embedded sensor wireless power supply system.

[0005] Therefore, in the face of the complex electromagnetic environment inside concrete, how to eliminate the interference of eddy currents in the reinforcing bars and achieve accurate positioning of the concealed receiver is a technical problem that needs to be solved urgently in the wireless power supply system for pre-embedded sensors. Summary of the Invention

[0006] The purpose of this invention is to solve the problem that existing technologies cannot accurately locate concealed energy receivers after concrete pouring. Addressing the technical limitations of existing rebar scanning equipment in distinguishing between ordinary rebar nodes and receivers, and the severe interference of eddy current effects in conventional electromagnetic positioning, this invention proposes a receiver and rebar mesh positioning device and method for a pre-embedded sensor wireless power supply system. By utilizing the different eddy current distribution characteristics generated by the rebar mesh and the receiver under an excitation magnetic field, accurate identification and positioning of the receiver can be achieved.

[0007] To achieve the above objectives, the present invention employs the following technical means:

[0008] The present invention provides a receiving end of a wireless power supply system for embedded sensors and a steel bar mesh positioning device, including a transmitting end and a detecting end:

[0009] The transmitting end includes a DC power supply, an inverter, a primary LCC compensation network, and an excitation coil L E and the primary winding L of a decoupling transformer SE ;

[0010] The DC power supply is connected to the input end of the inverter;

[0011] The inverter is connected to the primary LCC compensation network;

[0012] The primary LCC compensation network is connected to the excitation coil L E and the primary winding L of the decoupling transformer SE ; The excitation coil L E is connected in series with the primary winding L of the decoupling transformer SE to form a high-frequency transmitting loop;

[0013] The detecting end includes a four-quadrant detecting coil, the secondary winding L of a decoupling transformer SD and a signal detecting module;

[0014] The four-quadrant detecting coil includes four sub-coils distributed in a "field" shape;

[0015] Two sub-coils located at diagonal positions are connected in reverse series to form a first detecting loop for outputting a main detecting voltage;

[0016] Two sub-coils located at the other diagonal position are connected in reverse series to form a second detecting loop for outputting a secondary detecting voltage;

[0017] The first detecting loop and the second detecting loop are respectively connected to the signal detecting module;

[0018] There is mutual inductance coupling between the primary winding L of the decoupling transformer SE and the secondary winding L<o000009>configured to cancel the direct coupling interference of the excitation coil on the detecting loop.

[0019] In the above device, the primary LCC compensation network includes a compensation inductor L1, a parallel compensation capacitor C1, and a series compensation capacitor C E ;

[0020] One end of the compensation inductor L1 is connected to the output end of the inverter, and the other end is connected to the parallel compensation capacitor C1 and the series compensation capacitor C E ;

[0021] The series compensation capacitor C E It should be noted that there is a possible error in the original text where "o000009" in line might be a typo. It should probably be " SD ". This translation is based on the provided text with this potential error considered.With the excitation coil L E and the primary winding L of the decoupling transformer SE Series connection.

[0022] The above-mentioned device is characterized in that:

[0023] The parameters of the primary-side LCC compensation network are configured to satisfy the following resonance relationship so that the excitation current in the excitation coil remains constant when the load changes:

[0024]

[0025] In the formula, ω is the system's operating angular frequency.

[0026] The above-mentioned device is characterized in that:

[0027] The decoupling transformer is configured to generate a compensation voltage in the detection circuit through mutual inductance coupling. This compensation voltage has the same amplitude but opposite phase as the induced voltage generated by the excitation coil in the detection circuit, thus canceling each other out.

[0028] The mutual inductance parameters of the decoupling transformer satisfy the decoupling condition: M S = M ED2 - M ED3 M ED2 and M ED3 These are the inherent mutual inductances between the excitation coil and the two diagonally opposite sub-coils.

[0029] In the above device, the excitation coil is wound around the magnetic core in a cross-shaped structure.

[0030] In the above device, the four-quadrant detection coil is laid flat and located below the magnetic core, and is integrated with the excitation coil to form an integrated detection probe.

[0031] The present invention also provides a method for positioning a pre-embedded sensor wireless power supply system receiver and a rebar mesh using the aforementioned device, comprising the following steps:

[0032] Generating an excitation field: Injecting a high-frequency alternating current into the excitation coil generates an alternating magnetic field in the area under test, which excites the steel reinforcement network inside the concrete to generate induced eddy currents.

[0033] Signal reading: Using the signal detection module, the main detection voltage and secondary detection voltage are acquired in real time and processed by filtering, calculating the effective value, etc.

[0034] Positioning and discrimination: The detection end is controlled to move within the measured plane, and the effective value change characteristics of the main detection voltage and the secondary detection voltage are monitored in real time. The position of the rebar node or receiving end is identified based on the maximum value state of the voltage distribution.

[0035] In the above method, the location determination step specifically adopts the following location determination logic:

[0036] Initial node location: First, search for the location where the effective value of the main detection voltage reaches a maximum value, and determine this location as the initial rebar node;

[0037] The receiving end determines: taking the initial rebar node as a reference, it controls the detection end to move along the rebar direction and monitors the effective values ​​of the main detection voltage and the secondary detection voltage in real time;

[0038] Judgment logic: If at a certain position, the effective values ​​of the main detection voltage and the secondary detection voltage simultaneously reach a maximum value, then the current position is determined to be the receiving end position;

[0039] If only the effective value of the main detection voltage shows a maximum value while the effective value of the secondary detection voltage does not show a maximum value, then the current position is determined to be an ordinary rebar node.

[0040] If the effective value of the secondary detection voltage is at a maximum while the effective value of the primary detection voltage is not at a maximum, then the current location is determined to be the middle area of ​​ordinary reinforcing bars.

[0041] In the above method, the localization and discrimination step adopts a four-stage search strategy:

[0042] Phase 1: The horizontal movement of the detection end searches for the maximum value of the main detection voltage's effective value, and then uses this as a reference to move vertically to locate the maximum value of the main detection voltage's effective value, which serves as the initial node;

[0043] Second stage: Move along the longitudinal reinforcement and traverse all the maximum points of the effective value of the main detection voltage. If a point is also the maximum point of the effective value of the secondary detection voltage, it is confirmed as the receiving end.

[0044] Third stage: If the second stage is not found, move along the transverse steel bar starting from the ordinary steel bar node, traverse all the maximum value points of the main detection voltage effective value, and if a certain point is also the maximum value point of the secondary detection voltage effective value, then it is confirmed as the receiving end.

[0045] Fourth stage: If no point is found in the previous stages, then the point obtained from the horizontal search is used as the starting point for the vertical search point by point until a point that meets the double maximum value characteristic is found.

[0046] Compared with existing technologies, the present invention has the following advantages:

[0047] 1) This invention solves the problem of direct coupling interference between a strong excitation magnetic field and the detection coil by using a decoupling transformer connected in series in the transmitting and detecting circuits. Specifically, the primary winding L of the decoupling transformer... SE Series connection to the excitation circuit, secondary winding L SDBy connecting the detection circuit in series and utilizing the principle of magnetic field cancellation, the direct coupling interference of the strong excitation magnetic field on the detection coil is eliminated, enabling the detection coil to purely sense and output the weak electromagnetic response signal generated by the steel reinforcement network and the receiving end, thus realizing the extraction of weak features under a strong magnetic field.

[0048] 2) This invention relies entirely on the passive eddy current effect for positioning, and does not require the energy receiver to have any power or feedback circuit. This solves the problem of being unable to locate and maintain the embedded sensor after the battery is depleted, and reduces the complexity and cost of the receiver.

[0049] 3) The detection coil of this invention has a compact structure and can be directly integrated into the transmitter of a wireless power supply system. This structure allows the system to complete positioning and power supply tasks using the same set of devices. After locking the receiver's position through positioning, wireless power supply can be directly provided at the current location without changing equipment or recalibrating, achieving a seamless connection from precise positioning to efficient power supply.

[0050] 4) The positioning logic of this invention is based on the distribution characteristics of differential voltage extrema, rather than relying on absolute voltage amplitude, thus exhibiting strong robustness to the geometric dimensions of the reinforcing steel mesh. With a fixed detection end size, this system is applicable to dense or sparse meshes with varying spacing, as well as irregular mesh structures such as rectangles. This is achieved by analyzing the main detection voltage V... D_main and the detection voltage V D_sec By observing the changing trends, the system can accurately identify the location of rebar nodes or receiving ends, reducing the difficulty of project implementation and equipment costs. Attached Figure Description

[0051] Figure 1 is an overall circuit topology diagram of the receiver of the pre-embedded sensor wireless power supply system and the steel mesh positioning system of the present invention.

[0052] Figure 2 is a schematic diagram of the spatial structure of the cross-shaped excitation coil and the bottom grid-shaped detection coil in this invention. In the figure, L... D1 For detecting coil 1, L D2 For detecting coil 2, L D3 For detecting coil 3, L D4 For detection coil 4, F is a ferrite core, and L... E For the excitation coil;

[0053] Figure 3 is a cloud map showing the distribution of the effective value of the induced voltage above the reinforcing mesh after the detection coil is connected in reverse series.

[0054] Figure 4 is a flowchart of the first-stage search strategy of the receiver and steel mesh positioning method;

[0055] Figure 5 is a flowchart of the second-stage search strategy of the receiver and steel mesh positioning method;

[0056] Figure 6 is the flowchart of the search strategy in the third stage of the receiver and the steel bar mesh positioning method;

[0057] Figure 7 is the flowchart of the search strategy in the fourth stage of the receiver and the steel bar mesh positioning method;

[0058] Figure 8 is the positioning trajectory diagram according to the search strategy;

[0059] Figure 9 shows the change trend of V D_main_rms and V D_sec_rms during the positioning process. Specific Embodiments

[0060] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] The present invention constructs a receiving end of a wireless power supply system for embedded sensors, a steel bar mesh positioning device, and a method. Physically, the device consists of a primary energy transmitting end and a detection end.

[0062] The primary transmitting end includes a DC power supply, a full-bridge inverter composed of switching tubes Q1-Q4, a primary LCC compensation network, an excitation coil L E and the primary winding L of the decoupling transformer SE ;

[0063] The LCC compensation network includes a compensation inductor L1, a parallel compensation capacitor C1, a series compensation capacitor C E and the excitation coil L E , and the excitation coil L E is connected in series with the primary winding L of the decoupling transformer SE to form a high-frequency transmitting loop. As a possible implementation, specifically, one end of the compensation inductor L1 is connected to the inverter, and the other end is connected to one end of the parallel compensation capacitor C1 and one end of the series compensation capacitor C E ; the series compensation capacitor C E , the excitation coil L E , and the primary winding L of the decoupling transformer SE are connected in series in sequence to form a high-frequency transmitting loop; the excitation coil L E is wound around the ferrite core in a cross structure to generate an excitation magnetic field in the measured area;

[0064] The detection end includes a four-quadrant detection coil, the secondary winding (L SD ) of the decoupling transformer, and a signal detection module; the four-quadrant detection coil includes four sub-coils distributed in a "field" shape, namely sub-coil one L D1 , sub-coil two L D2 , sub-coil three LD3 Watsuno coil four L D4 It is integrated with the excitation coil to form an integrated detection probe;

[0065] Four detection coils (L) located below the ferrite core, arranged in a four-quadrant configuration. D1 L D2 L D3 L D4 This is used to capture the secondary induced magnetic field generated by the aforementioned eddy currents. To eliminate the direct coupling interference of the strong primary magnetic field generated by the excitation coil to the detection coil, the system introduces a decoupling transformer structure, which decouples its primary winding L... SE Series connection to the excitation circuit, secondary winding L SD A series connection is made to the detection circuit, and the coupling interference between the excitation coil and the detection coil is eliminated through the mutual inductance cancellation principle. Specifically, decoupling transformers are connected in series in both the excitation coil circuit and the detection coil circuit, and the mutual inductance parameters (M) of the decoupling transformers are precisely designed. S This causes the induced electromotive force generated to interact with the inherent mutual inductance (M) between the excitation coil and the detection coil. ED The generated electromotive forces are equal in magnitude and opposite in direction. Taking detection coils 2 and 3 as an example, when the decoupling condition M is satisfied... S2 =M ED2 and M S3 =M ED3 At this time, the direct coupling voltage caused by the excitation coil in the detection circuit is completely canceled out, so that the output voltage of the detection coil no longer contains the voltage caused by the excitation current I. E The voltage component is generated directly, thus ensuring that the output signal is excited only by the steel reinforcement network and the induced eddy currents at the receiving end.

[0066] As one possible implementation, the detection end is configured as a dual-channel differential output structure, wherein the sub-coil located at the diagonal position is L D2 Wawa coil three L D3 Connected in reverse series with the secondary winding L of the decoupling transformer. SD The coils are connected in series to form the first detection circuit, which is used to output the main detection voltage; the sub-coil L is located diagonally. D1 Watsuno coil four L D4 The circuit is connected in reverse series to form a second detection circuit independent of the decoupling transformer, used to output the secondary detection voltage; the signal detection module is connected to the output terminals of the first and second detection circuits respectively; the primary winding L of the decoupling transformer SE With secondary winding L SDMutual inductance coupling exists between the excitation coil and the detection circuit, and the configuration is designed to cancel the direct coupling interference from the excitation coil to the detection circuit. Based on this, this invention establishes an eddy current field detection model and feature extraction method based on the impedance analysis of the reinforcing steel network. According to Kirchhoff's Voltage Law (KVL), the induced eddy current distribution within the reinforcing steel network depends on the excitation mutual inductance matrix and the reinforcing steel network impedance matrix. When a receiving end exists within the concrete, the introduced reflection impedance will significantly alter the equivalent impedance of the corresponding mesh. This leads to the mesh current matrix in that local region. A specific distortion occurs. To extract this weak feature, this invention employs a diagonal reverse series connection strategy to define the characteristic voltage: the main detection voltage is obtained by reverse-connecting detection coil 2 and detection coil 3 at diagonal positions. The detection voltage is obtained by connecting detection coil 1 and detection coil 4 in reverse series. The main detection voltage V D_main and the detection voltage V D_sec The signal can be acquired by the signal detection module and processed by filtering, calculating the effective value, etc.

[0067] Based on electromagnetic field theory analysis and circuit model derivation, there is a clear mapping relationship between the aforementioned characteristic voltage and the position of the detection end: when the detection end is directly opposite the rebar node or the receiving end, due to the central symmetry of the eddy current field, the effective value of the main detection voltage V D_main_rms It exhibits a maximum value; however, when the detection end is located above the center area of ​​the rebar, the effective value of the secondary detection voltage V... D_sec_rms It exhibits a maximum value. More importantly, the connection of the receiving end alters the intensity and distribution pattern of the local vortex field, causing V at that location to... D_main_rms The amplitude will be significantly different from that of a typical pure steel reinforcement node. This invention utilizes this physical law by searching for V... D_main_rms The global maximum point is used to lock the target position, and combined with V D_sec_rms The distribution characteristics help determine the real-time attitude of the detection end relative to the steel mesh, thus achieving accurate identification and positioning of the concealed receiver without the need for complex communication and additional power supply.

[0068] This invention is mainly used to generate a magnetic field in space by an excitation coil after the concrete is poured, which in turn excites the steel reinforcement network to generate induced eddy currents, thereby accurately locating the receiving end hidden inside the concrete.

[0069] To facilitate a better understanding of the technical concept of this invention by those skilled in the art, the invention will be further described below with reference to the accompanying drawings:

[0070] Example 1

[0071] First, the system circuit topology is determined as shown in Figure 1. The system mainly consists of a primary-side energy emitter and a detection terminal. The primary-side energy emitter includes a DC power supply, an inverter composed of switching transistors Q1-Q4, and a compensation inductor L1, a compensation capacitor C1, and a compensation capacitor C2. E The LCC compensation network and the excitation coil L are composed of E The excitation coils are wound onto the ferrite in a cross-shaped pattern, with the X-direction and Y-direction excitation coils connected in series. The detection end consists of four detection coils (L...) located below the ferrite, arranged in a four-quadrant configuration. D1 L D2 L D3 L D4 It is composed of ) and wound in the same direction.

[0072] To eliminate the direct coupling interference between the excitation coil and the detection coil, a decoupling transformer is introduced, whose primary winding L... SE The secondary coil L is connected in series in the excitation circuit. SD Connected in series in the detection circuit, it is wound with two identical E-type magnetic cores, L SE Number of turns is 5, L SD The number of turns is 9, the air gap is 0.45mm, and the core thickness is 2cm.

[0073] Analyzing the system circuit, when the detection coil compensation loop is in a resonant state, the passive components in the circuit should satisfy the following resonant relationship:

[0074]

[0075] In the formula, ω is the system's operating angular frequency, and L E To excite the coil inductance, L SE To decouple the primary inductance of the transformer, L1 is a compensating inductor, C1, C E For compensation capacitors.

[0076] The system operating frequency f is set to 250kHz, and the specific parameters are configured as follows: L1 = 4.1μH, C1 = 97.3nF, L SE =20.09μH, L E =198.8μH, C E =1.885μF, input voltage U IN =8V.

[0077] To achieve decoupling between the excitation coil and the detection coil, the mutual inductance parameters of the decoupling transformer need to be precisely set. Taking detection coil 2 and detection coil 3 as an example, if they are connected in series in reverse, the mutual inductance M of the decoupling transformer will... S The following relationship should be satisfied:

[0078]

[0079] In the formula, M ED2 and M ED3 The inherent mutual inductance between the excitation coil and detection coils 2 and 3 are respectively, in this embodiment M S The voltage is configured to be 26.7μH. When this formula is satisfied, the output voltage of the detection coil is no longer directly affected by the excitation current, but is determined only by the eddy current.

[0080] Establish an equivalent circuit model including the excitation coil, the reinforcing steel network, and the detection coil. Define... To excite the mutual inductance between the coil and the nth steel mesh hole, For the impedance matrix of the reinforcement network, Let be the current matrix of the reinforcing steel mesh. According to Kirchhoff's Voltage Law (KVL), the current in the reinforcing steel mesh satisfies the following equation:

[0081]

[0082] in Z is the diagonal element of the matrix n_n Let Z be the self-impedance of the nth rebar mesh, including the equivalent resistance and self-inductance of the mesh conductors, and the off-diagonal element Z. n_k (n≠k) represents the mutual impedance between the nth and kth mesh openings. The mutual inductance between the coil and the reinforcing mesh is calculated using Ansys Maxwell simulation, and the current matrix is ​​obtained by substituting the values ​​into the equation. Then, using the following formula:

[0083] .

[0084]

[0085] in This represents the self-inductance of the nth mesh opening. Let represent the equivalent internal resistance of the nth mesh opening.

[0086] These represent the current in the 1st, 2nd, 3rd...nth rebar mesh openings, respectively.

[0087] Using the principle of mutual inductance, the open-circuit induced voltage V of each detection coil can be further obtained. D1 V D2 V D3 and V D4 The calculation formula is as follows:

[0088]

[0089] Indicates the detection coil ( ) and the Mutual inductance coefficient between individual steel mesh openings;

[0090] To extract positional features, the detection coils at diagonal positions are connected in reverse series, and the main detection voltage V is defined. D_main and the detection voltage V D_sec as follows:

[0091]

[0092] Based on the above definition, in terms of circuit connection, the diagonal detection coils are configured in reverse series, which directly outputs the differential voltage signal. Therefore, by connecting the signal detection module to the output terminal of the detection circuit, the main detection voltage V can be directly read. D_main and the detection voltage V D_sec This enables direct hardware-level extraction of feature signals.

[0093] Figure 3 shows the distribution cloud map of the effective value of the induced voltage above the steel reinforcement network after the detection coils are connected in reverse series. The induced voltage V of detection coils 3 and 2 is shown in Figure 3. D_main The trend of the effective value change is shown in the left figure of Figure 3, which detects the induced voltage V of coils 1 and 4. D_sec The trend of the effective value is shown in the right figure of Figure 3. According to the electromagnetic field distribution law, when the detection end is directly opposite the rebar node or the receiving end, V D_main It exhibits a maximum value; when the detection end is located in the middle of the rebar, V D_sec It exhibits a maximum value. This pattern holds true for different steel mesh sizes: for regular meshes such as 15cm×15cm, 20cm×20cm, and 10cm×10cm, as well as an irregular mesh of 20cm×10cm, the induced voltage distribution after reverse series connection is more symmetrical, and the extreme point characteristics are clearer; when a receiving end is present, its position will become V. D_main and V D_sec It is the global maximum point, and its amplitude is significantly higher than that of ordinary rebar nodes.

[0094] Based on the voltage characteristics described above, a positioning operation is performed. As shown in Figure 4, the first stage involves searching for the initial node, marking the starting point as A, and moving the detection end laterally by 20cm, recording V. D_main_rms and V D_sec_rms Trend of change. Marked with V D_main_rms The maximum value is located at point B. At this point, B may be located at the rebar or near the receiving coil. Move longitudinally 20cm from point B and record V.D_main_rms and V D_sec_rms Trend of change, located at V D_main_rms The maximum value is marked as C0. Determine whether C0 is V based on the recorded data. D_sec_rms If the value is not a maximum point, it means C0 is a regular rebar node, and we proceed to the second stage of positioning. If it is a maximum point, we need to move laterally to determine if C0 is also a V-shaped node in that direction. D_main_rms and V D_sec_rms If the maximum value is found, it indicates that C0 is the location of the receiving end; otherwise, it indicates that C0 is a normal node, and the second stage of positioning begins.

[0095] If the receiving end is not located in the first stage, the second stage proceeds with longitudinal movement, as shown in Figure 5, searching for more rebar nodes while simultaneously searching for the receiving end. Starting from C0, the longitudinal movement is performed as far as possible within the movable range, and V is recorded. D_main_rms and V D_sec_rms The trend of change is marked as C, and all the maximum points are recorded. i Based on the recorded data, determine C. i Is it V? D_sec_rms The maximum point, if not, indicates that C i This is a typical rebar node. If it's a maximum value point, further lateral movement is needed to determine C. i Is it simultaneously V in this direction? D_main_rms and V D_sec_rms The maximum point, if it indicates that C i This indicates the location of the receiving end; if not, it indicates C. i For ordinary rebar nodes, proceed to the third stage of positioning. In this stage, all nodes of the longitudinal rebar where the initial node is located are identified, and then proceed to the next stage of positioning.

[0096] If the vertical search fails, the third stage, lateral movement, begins, as shown in Figure 6. The lateral movement starts from the first identified rebar node. Using C as the starting point... i Starting from a point, move laterally within the movable range and record V. D_main_rms and V D_sec_rms Trend of change, mark all V D_main_rms The maximum point is D. i_j Determine D based on the recorded data. i_j Is it V? D_sec_rms The maximum point, if not, indicates that D i_j For ordinary rebar nodes, if it is a maximum value point, it is necessary to move it longitudinally to determine D. i_j Is it simultaneously V in this direction? D_main_rms and V D_sec_rms The maximum point indicates that D i_j This indicates the location of the receiving end; if not, it means D. i_jThis is a regular rebar node. Iterate through all C... i This stage allows all transverse reinforcing bars to be traversed. If the receiving end is still not located, proceed to the next stage.

[0097] The first three stages of the search have retrieved all the rebar nodes, but only all transverse rebars have been traversed, not all longitudinal rebars. The fourth stage is a point-by-point search, as shown in Figure 7, traversing all remaining longitudinal rebars. Let D... 0_j Starting from a point, move laterally within the movable range and record V. D_main_rms and V D_sec_rms Trend of change, mark all V D_main_rms The maximum point is E j_n Determine E based on the recorded data j_n Is it V? D_sec_rms The maximum point, if not, indicates that E j_n For ordinary rebar nodes, if it is a maximum value point, it is necessary to move laterally to determine E. j_n Is it simultaneously V in this direction? D_main_rms and V D_sec_rms The maximum point indicates that E j_n This indicates the location of the receiving end; if not, it indicates E. j_n This is a regular reinforced concrete node. Iterate through D. 0_0 To D 0_jmax Starting from the longitudinal search trajectory, all steel bars within the movable range can be searched point by point.

[0098] During the experimental positioning process, the movement interval of the detection end was set to 20cm, and the signal detection module acquired the main detection voltage V in real time. D_main and the detection voltage V D_sec The acquired signals were then low-pass filtered, and their effective values ​​were calculated as key feature parameters for subsequent localization algorithm maxima search and logical judgment. The experiment used a 4×4 welded steel mesh with a grid spacing of 15cm×15cm, steel bar diameter of 12mm, and the bottom of the detection end was 4cm from the surface of the steel mesh.

[0099] Figure 8 shows the positioning trajectory based on the above search strategy. Starting from point A (10cm, 10cm), it moves laterally 20cm along the negative X-axis. During the movement, V... D_main_rms The trajectory of the change is shown by the solid line marked by the circular marker in Figure 9(a). The extreme point B is obtained through this curve; then, starting from B, the line moves longitudinally for 20cm along the negative Y-axis. D_main_rms The trend of change is shown by the curve marked with a square in Figure 9(a), V D_sec_rms The trend of change is shown by the curve marked with a square in Figure 9(b), where point C is simultaneously V. D_main_rms and VD_sec_rms The maximum point. Then move the detection end laterally, V D_main_rms The trend of change is shown by the curve marked with a triangle in Figure 9(a), V D_sec_rms The trend of change is shown by the curve marked by the triangle in Figure 9(b), where point C is simultaneously V. D_main_rms and V D_sec_rms The maximum value point is C, therefore point C is the location of the receiving end.

[0100] Once the positioning is complete, the detection end is positioned directly above the receiving end, meaning the system can wirelessly power the pre-embedded sensor receiver at the current location.

Claims

1. A receiver for a pre-embedded sensor wireless power supply system and a steel mesh positioning device, characterized in that, It includes a transmitting end and a detecting end: The transmitting end includes a DC power supply, an inverter, a primary LCC compensation network, an excitation coil L E and the primary winding L of a decoupling transformer SE ; The DC power supply is connected to the input end of the inverter; The inverter is connected to the primary LCC compensation network; The primary LCC compensation network is connected to the excitation coil L E and the primary winding L of the decoupling transformer SE ; The excitation coil L E and the primary winding L of the decoupling transformer SE are connected in series to form a high-frequency transmitting loop; The detecting end includes a four-quadrant detecting coil, the secondary winding L of the decoupling transformer SD and a signal detecting module; The four-quadrant detecting coil includes four sub-coils distributed in a "field" shape; Two sub-coils located at diagonal positions are connected in reverse series to form a first detecting loop for outputting a main detecting voltage; Two sub-coils located at the other diagonal position are connected in reverse series to form a second detecting loop for outputting a secondary detecting voltage; The first detecting loop and the second detecting loop are respectively connected to the signal detecting module; There is mutual inductance coupling between the primary winding L SE and the secondary winding L SD of the decoupling transformer, configured to cancel the direct coupling interference of the excitation coil on the detecting loop.

2. The receiver of the pre-embedded sensor wireless power supply system and the steel mesh positioning device according to claim 1, characterized in that: The primary-side LCC compensation network includes a compensation inductor L1, a parallel compensation capacitor C1, and a series compensation capacitor C. E One end of the compensation inductor L1 is connected to the inverter output terminal, and the other end is connected to the parallel compensation capacitor C1 and the series compensation capacitor C. E The series compensation capacitor C E With the excitation coil L E and the primary winding L of the decoupling transformer SE Series connection.

3. The receiver of the pre-embedded sensor wireless power supply system and the steel mesh positioning device according to claim 2, characterized in that: The parameters of the primary-side LCC compensation network are configured to satisfy the following resonance relationship so that the excitation current in the excitation coil remains constant when the load changes: In the formula, ω is the system's operating angular frequency.

4. The receiver of the pre-embedded sensor wireless power supply system and the steel mesh positioning device according to claim 1, characterized in that: The decoupling transformer is configured to generate a compensation voltage in the detection circuit through mutual inductance coupling. This compensation voltage has the same amplitude but opposite phase to the induced voltage generated by the excitation coil in the detection circuit, thus canceling each other out. The mutual inductance parameters of the decoupling transformer satisfy the decoupling condition: M S = M ED2 - M ED3 M ED2 and M ED3 These are the inherent mutual inductances between the excitation coil and the two diagonally opposite sub-coils.

5. The receiver of the pre-embedded sensor wireless power supply system and the steel mesh positioning device according to claim 1, characterized in that: The excitation coil is wound around the magnetic core in a cross-shaped structure.

6. The receiver of the pre-embedded sensor wireless power supply system and the steel mesh positioning device according to claim 1, characterized in that: The four-quadrant detection coil is laid flat and located below the magnetic core, and is integrated with the excitation coil to form an integrated detection probe.

7. A method for locating a receiver and reinforcing mesh in a pre-embedded sensor wireless power supply system using the device described in any one of claims 1-6, characterized in that, Includes the following steps: Generating an excitation field: Injecting a high-frequency alternating current into the excitation coil generates an alternating magnetic field in the measured area, which excites the steel reinforcement network inside the concrete to generate induced eddy currents; Signal reading: Using the signal detection module, the main detection voltage and the secondary detection voltage are collected in real time and processed by filtering, calculating the effective value, etc. Positioning and discrimination: The detection end is controlled to move within the measured plane, and the effective value change characteristics of the main detection voltage and the secondary detection voltage are monitored in real time. The position of the rebar node or receiving end is identified based on the maximum value state of the voltage distribution.

8. The method according to claim 7, characterized in that: The positioning and discrimination step specifically adopts the following position determination logic: Initial node positioning: First, search for the position where the effective value of the main detection voltage is maximized, and determine the position as the initial rebar node; Receiver determination: With the initial rebar node as a reference, control the detection end to move along the rebar direction and monitor the effective values ​​of the main detection voltage and the secondary detection voltage in real time. Judgment logic: If at a certain position, the effective values ​​of the main detection voltage and the secondary detection voltage simultaneously reach a maximum value, then the current position is determined to be the receiving end position; If only the effective value of the main detection voltage shows a maximum value while the effective value of the secondary detection voltage does not show a maximum value, then the current position is determined to be an ordinary rebar node. If the effective value of the secondary detection voltage is at a maximum while the effective value of the primary detection voltage is not at a maximum, then the current location is determined to be the middle area of ​​ordinary reinforcing bars.

9. The method according to claim 7, characterized in that: The positioning and discrimination step adopts a four-stage search strategy: the first stage: the detection end is moved laterally to search for the maximum value of the effective value of the main detection voltage, and then the detection end is moved longitudinally to locate the maximum value of the effective value of the main detection voltage as the initial node. The second stage: Move along the longitudinal reinforcement and traverse all the maximum points of the main detection voltage effective value. If a point is also the maximum point of the secondary detection voltage effective value, it is confirmed as the receiving end. The third stage: If it is not found in the second stage, move along the transverse reinforcement with the ordinary reinforcement node as the starting point and traverse all the maximum points of the main detection voltage effective value. If a point is also the maximum point of the secondary detection voltage effective value, it is confirmed as the receiving end. The fourth stage: If it is not found in the previous stages, start from the point obtained by the transverse search and perform a longitudinal point-by-point search until a point that meets the double maximum value characteristics is found.

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