A track recognition sensor based on flexible self-sensing material, a preparation method and a use method

Abstract

This invention discloses a wheel track recognition sensor based on a flexible self-sensing material, its preparation method, and its application method, belonging to the technical field of wheel track recognition sensors. The wheel track recognition sensor includes a sensitive sensing core material, an insulating polymer inner encapsulation layer, a conductive shielding layer, a polymer outer encapsulation layer, and conductive electrodes. The sensitive sensing core material is formed by extruding conductive filler and a flexible polymer matrix material. The insulating polymer inner encapsulation layer covers the outside of the sensitive sensing core material. The conductive shielding layer is disposed outside the insulating polymer inner encapsulation layer and extends continuously along the length of the sensitive sensing core material. The conductive shielding layer is a metallic conductive shielding layer. The polymer outer encapsulation layer covers the outside of the conductive shielding layer. Conductive electrodes are disposed at both ends of the sensitive sensing core material and electrically connected to it. This invention, using the above-mentioned wheel track recognition sensor, preparation method, and application method, improves the consistency and stability of sensor performance and optimizes material dispersion and conductive network structure.

Description

Technical Field

[0001] This invention relates to the field of wheel track recognition sensor technology, and in particular to a wheel track recognition sensor based on flexible self-sensing material, its preparation method, and its usage method. Background Technology

[0002] Vehicle wheel track recognition technology is a crucial foundation for intelligent road monitoring, vehicle-road cooperation, and pavement structure health management. Its core objective is to acquire information on the lateral position distribution of vehicles within lanes, providing data support for traffic operation status analysis, pavement load spectrum statistics, and the evolution of typical pavement defects such as ruts. With the development of intelligent transportation systems, higher demands are placed on the accuracy, continuity, and long-term stability of vehicle wheel track monitoring. The manufacturing technology and positioning methods of flexible, continuous, distributed sensors have gradually become research hotspots in related fields.

[0003] Current road wheel track sensing technologies primarily rely on discretely deployed point sensor arrays or image-based visual recognition systems. Among these, contact-type sensing elements such as piezoelectric sensors and strain gauges typically require multi-unit splicing or complex calibration arrays to achieve wheel track identification. This not only results in high deployment and maintenance costs but also, due to the physical gaps between sensing units, makes continuous perception of wheel tracks in the lateral direction of the lane difficult, easily creating blind spots and limiting the accurate identification of minute wheel track deviations. While visual recognition methods offer the advantage of being non-contact, their accuracy and stability are easily affected by lighting, pollution, and weather conditions, making it difficult to meet the needs of all-weather, long-term monitoring.

[0004] In the field of long-range flexible sensors, existing fabrication processes mostly employ solution blending or molding, which makes it difficult to effectively control the distribution of conductive fillers in the polymer matrix. This results in insufficient continuity and stability of the conductive network, limiting their application in long-distance transmission and continuous sensing scenarios. Furthermore, existing flexible sensors are mostly in the form of discrete segments or short-range elements, and an integrated long-scale sensing structure suitable for continuous vehicle wheel track positioning has not yet been developed.

[0005] Furthermore, to achieve accurate positioning of vehicle wheel tracks in the lateral direction of the lane, the sensor not only needs to be flexible and durable, but also needs to have stable distributed parameter transmission characteristics in its structure, so that the local electrical response caused by wheel track loading can be reliably propagated along the length of the sensor and effectively identified.

[0006] Therefore, there is an urgent need for a flexible self-sensing material extrusion process that can achieve uniform dispersion of conductive fillers and form a stable distributed parameter transmission structure, as well as a matching method for continuous distributed sensitive sensor manufacturing and vehicle wheel track recognition and positioning, to meet the needs of continuous monitoring and accurate identification of vehicle wheel tracks in smart roads. Summary of the Invention

[0007] The purpose of this invention is to provide a wheel track recognition sensor based on flexible self-sensing materials, its preparation method, and its usage method, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides a wheel track recognition sensor based on a flexible self-sensing material, comprising a continuously extending sensitive sensing core, an insulating polymer inner encapsulation layer, a conductive shielding layer, a polymer outer encapsulation layer, and conductive electrodes. The sensitive sensing core is formed by extruding conductive filler and a flexible polymer matrix material together using an extruder. The insulating polymer inner encapsulation layer covers the outside of the sensitive sensing core. The conductive shielding layer is disposed outside the insulating polymer inner encapsulation layer and extends continuously along the length of the sensitive sensing core. The conductive shielding layer is a metallic conductive shielding layer. The polymer outer encapsulation layer covers the outside of the conductive shielding layer. The conductive electrodes are disposed at both ends of the sensitive sensing core and electrically connected to the sensitive sensing core.

[0009] Preferably, the sensitive sensing core and the conductive shielding layer form a distributed parameter transmission structure under the isolation effect of the inner encapsulation layer of the insulating polymer; the conductive shielding layer is grounded to the external circuit to suppress external electromagnetic interference and serve as a reference conductor for the distributed parameter transmission structure.

[0010] This invention also provides a method for fabricating a wheel track recognition sensor based on a flexible self-sensing material, comprising the following steps: S1. Mix the conductive filler and the flexible polymer matrix material in a certain mass ratio to prepare a premix; S2. Add the premixed material to a twin-screw or multi-screw extruder for melt blending and extrusion; S3. Formed into a continuous strip-shaped sensitive sensing core material through an extruder die; S4. Attach and fix conductive electrodes to both ends of the sensitive sensing core material, and cover the outside of it with insulating polymer to form a continuous insulating polymer inner encapsulation layer. S5. A continuous conductive shielding layer is provided along the length direction on the outside of the inner encapsulation layer of the insulating polymer, so that the conductive shielding layer and the sensitive sensing core material form a coaxial distributed parameter transmission structure under the isolation effect of the inner encapsulation layer of the insulating polymer. S6. Polymer external encapsulation is performed on the outside of the conductive shielding layer to form a complete continuous distributed sensitive sensor.

[0011] Preferably, S3 specifically involves: through multiple extrusion processes such as cooling pelletizing and re-extrusion, the conductive filler forms a continuous, uniform, and oriented conductive network structure in the polymer matrix, thereby obtaining a strip-shaped sensitive sensing core material.

[0012] Preferably, the flexible polymer matrix material is at least one of the following: EAA, TPU and HDPE; the conductive filler is at least one of the following: CB, CNTS, CF, graphene, copper powder, nickel powder, nano silver, steel fiber, aluminum powder, iron tetroxide, titanium dioxide and silicon carbide.

[0013] Preferably, the conductive shielding layer in S2 is formed by wrapping metal wire, metal braided mesh or metal foil material around the outside of the inner encapsulation layer of the insulating polymer in a spiral winding or braiding manner to form a continuous conductive shielding layer along the length direction.

[0014] Preferably, the present invention also provides a method for using a wheel track recognition sensor based on a flexible self-sensing material, comprising the following steps: Wheel track recognition sensors are laid laterally along the lane. The length of the wheel track recognition sensors corresponds one-to-one with the lateral position of the lane or at least covers the wheel track strips on both sides, thus constructing a linear sensing coordinate system for the lateral position of the vehicle's wheel tracks. A pulse excitation signal is applied to one or both ends of the wheel track recognition sensor, causing the pulse excitation signal to propagate along the coaxial distributed parameter transmission structure; When the vehicle tires act on the lane and are loaded onto the wheel track recognition sensor, the sensitive sensing core material at the corresponding position of the wheel track undergoes local mechanical deformation, which causes a change in the characteristic impedance of the coaxial distributed parameter transmission structure at that position and generates a pulse reflection signal at that position. Acquire the reflected signal and determine the time delay of the reflected signal relative to the pulse excitation signal; The position of the vehicle wheel track in the lateral direction of the lane is determined based on the time delay and the propagation speed of the pulse excitation signal in the coaxial distributed parameter transmission structure.

[0015] Preferably, the propagation speed of the pulse excitation signal in the coaxial distributed parameter transmission structure is obtained through pre-calibration.

[0016] The preferred, pre-calibrated calculation method is as follows: Assuming the wheel track recognition sensor has a length of... The time it takes for an electromagnetic wave to travel from one end to the other is Then the propagation speed for: ; in, The speed of light is taken as 3 × 10⁸ m / s; It is the relative electromagnetic coefficient; is the relative permittivity.

[0017] Preferably, the position of the vehicle wheel track in the lateral direction of the lane is determined based on the correspondence between time delay and propagation speed, thus obtaining the distance from the position of the vehicle wheel track in the lateral direction of the lane to the measurement point. for: ; in, This is the round-trip time delay from transmitting the excitation signal to receiving the reflected signal.

[0018] Therefore, the present invention employs the above-described wheel track recognition sensor based on flexible self-sensing material, its preparation method, and its usage method, which have the following beneficial effects: (1) Achieve efficient and uniform mixing and dispersion of conductive fillers in polymer matrix, thereby improving the consistency and reliability of sensing. Compared with the traditional solution blending method, the present invention achieves simultaneous application of "shear field" and "tension field" through melt blending extrusion using a twin screw extruder, which enables the conductive network to be uniformly oriented and avoids the formation of conductive agglomerates, thereby improving the consistency and stability of sensor performance and optimizing material dispersion and conductive network structure.

[0019] (2) Construct a linear continuous sensing mode based on continuous strip sensor to achieve a fundamental improvement in sensing dimension; unlike the limitation of traditional technology that can only perform single-point measurement, a continuous sensor is directly defined as the coordinate axis in physical space; thus realizing a dimensional leap from "point-like discrete sampling" to "linear continuous full-domain sensing".

[0020] (3) The axial consistency of the conductive network is achieved by using a continuous extrusion process, which improves the directionality and transmission efficiency of the sensing performance. This invention breaks through the traditional application of extrusion process as only a macroscopic forming method. Through a continuous extrusion process, the conductive filler is induced to align along the extrusion direction under high shear and high tension conditions, thereby constructing a conductive path with significant axial consistency. This structure is beneficial to reduce signal transmission loss and improve the consistency of electrical response along the length direction, providing a reliable material and structural basis for long-distance distributed sensing.

[0021] (4) Achieve precise lateral positioning of vehicle wheel tracks without the need for multi-point splicing and complex calibration.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a wheel track recognition sensor based on a flexible self-sensing material according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating a method for fabricating a wheel track recognition sensor based on a flexible self-sensing material, according to an embodiment of the present invention. Figure 3This is a schematic diagram illustrating the principle of a method for using a wheel track recognition sensor based on a flexible self-sensing material according to an embodiment of the present invention. Figure 4 This is a waveform diagram of the signal before it encounters impedance after pulse injection, according to an embodiment of the present invention. Figure 5 This is a waveform diagram of the signal encountering impedance after pulse injection, according to an embodiment of the present invention. Figure Labels 1. Conductive electrode; 2. Sensitive sensing core material; 3. Insulating polymer inner encapsulation layer; 4. Metal conductive shielding layer; 5. Polymer outer encapsulation layer; 6. Lane; 7. Continuous distributed sensitive sensor; 8. Vehicle tire; 9. Waveform of signal not encountering impedance after pulse injection; 10. Waveform of signal encountering impedance after pulse injection. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] like Figure 1As shown, this invention provides a wheel track recognition sensor based on a flexible self-sensing material, comprising a continuously extending sensitive sensing core 2, an insulating polymer inner encapsulation layer 3, a conductive shielding layer, a polymer outer encapsulation layer 5, and conductive electrodes 1. The sensitive sensing core 2 is formed by extruding conductive filler and a flexible polymer matrix material. The insulating polymer inner encapsulation layer 3 covers the outside of the sensitive sensing core 2. The conductive shielding layer is disposed outside the insulating polymer inner encapsulation layer 3 and extends continuously along the length of the sensitive sensing core 2. The conductive shielding layer is a metal conductive shielding layer 4. The polymer outer encapsulation layer 5 covers the outside of the conductive shielding layer. The conductive electrodes 1 are disposed at both ends of the sensitive sensing core 2 and electrically connected to it. The sensitive sensing core 2 and the conductive shielding layer form a distributed parameter transmission structure under the isolation effect of the insulating polymer inner encapsulation layer 3. The conductive shielding layer is grounded to the external circuit to suppress external electromagnetic interference and serves as a reference conductor for the distributed parameter transmission structure.

[0027] Reference Figure 2 The present invention also provides a method for fabricating a wheel track recognition sensor based on a flexible self-sensing material, comprising the following steps: S1. Mix the conductive filler with the flexible polymer matrix material at a mass ratio of 1%-20% to prepare a premix; S2. Add the premixed material to a twin-screw or multi-screw extruder and perform melt blending extrusion at an extrusion temperature of 60-400℃, a feeding speed of 1-200r / min, and a main machine speed of 1-200r / min. S3. The strip-shaped sensitive sensing core material 2 is formed through an extruder die, with a diameter controlled between 0.1 and 10 cm. Specifically, through multiple extrusion processes including cooling, pelletizing, and re-extrusion, the conductive filler forms a continuous, uniform, and oriented conductive network structure within the polymer matrix, thereby obtaining the strip-shaped sensitive sensing core material 2. This extrusion process helps improve the uniformity and stability of the conductive network, enhancing the consistency of the sensing signal during long-distance transmission.

[0028] S4. Attach and fix conductive electrodes 1 to both ends of the sensitive sensing core material 2, and cover the outside of it with insulating polymer to form a continuous insulating polymer inner encapsulation layer 3. S5. A continuous conductive shielding layer is provided along the length direction on the outside of the inner encapsulation layer 3 of the insulating polymer, so that the conductive shielding layer and the sensitive sensing core material 2 form a coaxial distributed parameter transmission structure under the isolation effect of the inner encapsulation layer 3 of the insulating polymer. S6. Polymer external encapsulation is performed on the outside of the conductive shielding layer to form a complete continuous distributed sensitive sensor 7.

[0029] The flexible polymer matrix material is one or more polymers such as EAA, TPU, and HDPE; the conductive filler is one or more conductive fillers such as CB, CNTS, CF, graphene, copper powder, nickel powder, nano silver, steel fiber, aluminum powder, iron tetroxide, titanium dioxide, and silicon carbide.

[0030] The conductive shielding layer in S2 is formed by wrapping metal wire, metal braided mesh or metal foil material around the outside of the inner encapsulation layer 3 of the insulating polymer in a spiral winding or braiding manner to form a continuous conductive shielding layer along the length direction.

[0031] Reference Figure 3 The present invention also provides a method for using a wheel track recognition sensor based on a flexible self-sensing material, comprising the following steps: Wheel track recognition sensors are laid laterally along lane 6. The length of the wheel track recognition sensors corresponds one-to-one with the lateral position of lane 6 or at least covers the wheel track strips on both sides, thereby constructing linear sensing coordinates of the lateral position of the vehicle wheel track. A pulse excitation signal is applied to one or both ends of the wheel track recognition sensor, causing the pulse excitation signal to propagate along the coaxial distributed parameter transmission structure; When the vehicle tire 8 acts on the lane 6 and is applied to the wheel track recognition sensor, the sensitive sensing core material 2 at the corresponding position of the wheel track undergoes local mechanical deformation, causing a change in the characteristic impedance of the coaxial distributed parameter transmission structure at that position, thereby generating a pulse reflection signal at that position; (Refer to...) Figures 4-5 , Figure 4 The waveform in the middle is the waveform 9 after the pulse injection when the signal does not encounter impedance; Figure 5 The waveform in the middle is waveform 10 when the signal encounters impedance after pulse injection. When the injected pulse signal is transmitted to the impedance mismatch point, part of the energy is reflected. The reflected wave is superimposed on the incident wave, thus forming a characteristic change in the waveform, that is, a step-shaped waveform is superimposed on the pulse signal when there is no impedance.

[0032] Acquire the reflected signal and determine the time delay of the reflected signal relative to the pulse excitation signal; Based on the time delay and the propagation speed of the pulse excitation signal in the coaxial distributed parameter transmission structure, the position of the vehicle wheel track in the lateral direction of lane 6 is determined, thereby achieving accurate identification of the lateral position of the vehicle wheel track.

[0033] The acquired reflection signals are subjected to wavelet transform denoising or moving average filtering to improve the signal-to-noise ratio, thereby extracting reflection features more accurately.

[0034] When determining the time delay, peak detection, threshold detection, or cross-correlation algorithms are used to accurately locate the start or peak time of the reflected signal pulse.

[0035] The propagation speed of the pulse excitation signal in the coaxial distributed parameter transmission structure is obtained through pre-calibration, specifically: Electromagnetic waves propagate in a conductor at a certain speed, which can be obtained through pre-calibration or by the following calculation method: assuming the length of the flexible sensor is... The time it takes for an electromagnetic wave to travel from one end to the other is Then wave speed for: ; in, The speed of light is taken as 3 × 10⁸ m / s; It is the relative electromagnetic coefficient; is the relative permittivity.

[0036] The position of the vehicle's wheel tracks in the lateral direction of lane 6 is determined based on the correspondence between time delay and propagation speed, specifically: If the round-trip time delay from transmitting the excitation signal to receiving the reflected signal is Then the distance from the position of the vehicle tire 8 acting on the lane 6 and loaded onto the wheel track recognition sensor to the measurement point can be calculated. : ; This invention utilizes continuously distributed flexible strip sensors deployed laterally in lane 6 to create linear sensing coordinate axes that correspond one-to-one with the lateral positions of lane 6. When a vehicle's wheel track acts on the road surface, a localized electrical response change occurs in the strip sensor area corresponding to the wheel track position. By detecting the distribution characteristics of this change within the continuous strip, precise positioning of the vehicle's wheel track in the lateral direction of lane 6 can be achieved without the need for multi-point sensor array splicing or complex calibration.

[0037] Example 1: This embodiment 1 provides a method for fabricating a wheel track recognition sensor based on a flexible self-sensing material, including the following steps: Step 1: Stir and mix the conductive filler (CB12) with the flexible polymer matrix material (EAA) to prepare a premix, wherein the content of CB12 is 10wt%.

[0038] Step 2: Set the temperatures of the three zones of the twin screw extruder to 140℃, 150℃, and 150℃ to preheat the machine.

[0039] Step 3: Add the premix to the micro twin-screw extruder. Considering that the melting point of EAA is about 120℃, in order to make the conductive filler form an orientation network better, the extrusion temperature of the second and third zones is set to 150℃ (about 30℃ higher than the melting point of the matrix), the feeding speed is set to 15r / min, the main machine speed is set to 25r / min, and the extrusion pressure is controlled at 3MPa.

[0040] Step 4: Extrude a continuous strip core material with a diameter of 0.5 cm through the die head. In order to ensure the dispersion of carbon black in the EAA matrix and the construction of the axial network, the extruded core material is granulated and added back into the extruder for two extrusions. Finally, it is cooled and shaped to obtain the sensitive sensing core material.

[0041] Step 5: Cut the required length of the sensing core material, apply conductive silver paste to both ends and attach copper electrodes. Then, insert a heat-shrink tubing with adhesive onto the outside of the core material, heat it to shrink, and form a tight insulating polymer inner encapsulation layer.

[0042] Step 6: Select a copper braided mesh as a conductive shielding layer, and wrap it around the outside of the insulating inner encapsulation layer to tightly cover it, thereby constructing a coaxial transmission structure. Step 7: Use PU (polyurethane) to pot the outside of the metal braided mesh. After curing, a robust polymer outer encapsulation layer is formed, producing a finished continuous distributed sensitive sensor.

[0043] Example 2: This embodiment 2 discloses a method for using a wheel track recognition sensor based on a flexible self-sensing material. The wheel track recognition sensor is manufactured using the method of embodiment 1. The specific steps of the method are as follows: Step 100: Install the wheel track recognition sensor laterally in the highway driving lane, covering a length of 3.75 meters of lane width.

[0044] Step 200: Connect a signal generator to one end of the wheel track recognition sensor and emit a nanosecond-level step pulse signal.

[0045] Step 300: Pre-calibrate the propagation speed of the pulse signal in the sensor. When a vehicle passes over it, the tires press down on the sensor, causing localized deformation of the sensor core material and resulting in a sudden impedance change that generates a reflection. The reflected signal is collected, and the time delay between the reflected signal and the excitation signal is determined using the peak detection method. After noise reduction using a moving average filter, the distance from the vehicle's wheel track to the measurement end can be calculated using the following formula, thus determining the vehicle's lateral position within the lane: ; in, The round-trip time delay from transmitting the excitation signal to receiving the reflected signal. The distance from the position of the vehicle tire acting on the lane and loaded onto the wheel track recognition sensor to the measurement point.

[0046] Therefore, the present invention employs the above-mentioned wheel track recognition sensor based on flexible self-sensing material, its preparation method, and its usage method. By constructing a continuous strip-shaped flexible sensitive sensor and its matching distributed parameter transmission structure, the continuous sensing and accurate positioning of vehicle wheel tracks in the lateral direction of the lane can be achieved.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A wheel track recognition sensor based on flexible self-sensing materials, characterized in that: The device comprises a continuously extending sensitive sensing core, an insulating polymer inner encapsulation layer, a conductive shielding layer, a polymer outer encapsulation layer, and conductive electrodes. The sensitive sensing core is formed by extruding conductive filler and a flexible polymer matrix material. The insulating polymer inner encapsulation layer covers the outside of the sensitive sensing core. The conductive shielding layer is disposed outside the insulating polymer inner encapsulation layer and extends continuously along the length of the sensitive sensing core. The conductive shielding layer is a metallic conductive shielding layer. The polymer outer encapsulation layer covers the outside of the conductive shielding layer. The conductive electrodes are disposed at both ends of the sensitive sensing core and are electrically connected to the sensitive sensing core.

2. The wheel track recognition sensor based on flexible self-sensing material according to claim 1, characterized in that: The sensitive sensing core and the conductive shielding layer form a distributed parameter transmission structure under the isolation effect of the inner encapsulation layer of the insulating polymer; the conductive shielding layer is grounded to the external circuit to suppress external electromagnetic interference and serve as a reference conductor for the distributed parameter transmission structure.

3. A method for fabricating a wheel track recognition sensor based on a flexible self-sensing material, comprising fabricating a wheel track recognition sensor based on a flexible self-sensing material as described in any one of claims 1-2, characterized in that, Includes the following steps: S1. Mix the conductive filler and the flexible polymer matrix material in a certain mass ratio to prepare a premix; S2. Add the premixed material to a twin-screw or multi-screw extruder for melt blending and extrusion; S3. Formed into a continuous strip-shaped sensitive sensing core material through an extruder die; S4. Attach and fix conductive electrodes to both ends of the sensitive sensing core material, and cover the outside of it with insulating polymer to form a continuous insulating polymer inner encapsulation layer. S5. A continuous conductive shielding layer is provided along the length direction on the outside of the inner encapsulation layer of the insulating polymer, so that the conductive shielding layer and the sensitive sensing core material form a coaxial distributed parameter transmission structure under the isolation effect of the inner encapsulation layer of the insulating polymer. S6. Polymer external encapsulation is performed on the outside of the conductive shielding layer to form a complete continuous distributed sensitive sensor.

4. The method for fabricating a wheel track recognition sensor based on a flexible self-sensing material according to claim 3, characterized in that: The conductive shielding layer in S2 is formed by wrapping metal wire, metal braided mesh or metal foil material around the outside of the inner encapsulation layer of the insulating polymer in a spiral winding or braiding manner to form a continuous conductive shielding layer along the length direction.

5. The method for fabricating a wheel track recognition sensor based on a flexible self-sensing material according to claim 3, characterized in that: The flexible polymer matrix material is at least one of the following: EAA, TPU and HDPE; the conductive filler is at least one of the following: CB, CNTS, CF, graphene, copper powder, nickel powder, nano silver, steel fiber, aluminum powder, iron tetroxide, titanium dioxide and silicon carbide.

6. The method for fabricating a wheel track recognition sensor based on a flexible self-sensing material according to claim 3, characterized in that, S3 specifically refers to the process of multiple extrusion processes, such as cooling pelletizing and re-extrusion, to form a continuous, uniform, and oriented conductive network structure in the polymer matrix, thereby obtaining a strip-shaped sensitive sensing core material.

7. A method of using a wheel track recognition sensor based on a flexible self-sensing material, comprising applying a wheel track recognition sensor based on a flexible self-sensing material as described in any one of claims 1-2, characterized in that, Includes the following steps: Wheel track recognition sensors are laid laterally along the lane. The length of the wheel track recognition sensors corresponds one-to-one with the lateral position of the lane or at least covers the wheel track strips on both sides, thus constructing a linear sensing coordinate system for the lateral position of the vehicle's wheel tracks. A pulse excitation signal is applied to one or both ends of the wheel track recognition sensor, causing the pulse excitation signal to propagate along the coaxial distributed parameter transmission structure; When the vehicle tires act on the lane and are loaded onto the wheel track recognition sensor, the sensitive sensing core material at the corresponding position of the wheel track undergoes local mechanical deformation, which causes a change in the characteristic impedance of the coaxial distributed parameter transmission structure at that position and generates a pulse reflection signal at that position. Acquire the reflected signal and determine the time delay of the reflected signal relative to the pulse excitation signal; The position of the vehicle wheel track in the lateral direction of the lane is determined based on the time delay and the propagation speed of the pulse excitation signal in the coaxial distributed parameter transmission structure.

8. The method of using a wheel track recognition sensor based on a flexible self-sensing material according to claim 7, characterized in that: The propagation speed of the pulse excitation signal in the coaxial distributed parameter transmission structure is obtained through pre-calibration.

9. A method for using a wheel track recognition sensor based on a flexible self-sensing material according to claim 8, characterized in that: The pre-calibrated calculation method is as follows: Assuming the wheel track recognition sensor has a length of... The time it takes for an electromagnetic wave to travel from one end to the other is Then the propagation speed for: ； in, The speed of light is taken as 3 × 10⁸ m / s; It is the relative electromagnetic coefficient; is the relative permittivity.

10. A method for using a wheel track recognition sensor based on a flexible self-sensing material according to claim 9, characterized in that: The position of the vehicle's wheel track in the lateral direction of the lane is determined based on the relationship between time delay and propagation speed, thus obtaining the distance from the position of the vehicle's wheel track in the lateral direction of the lane to the measurement point. for: ； in, This is the round-trip time delay from transmitting the excitation signal to receiving the reflected signal.

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