Fiber bragg grating dynamic truck scale device and system thereof

Abstract

The invention discloses a fiber bragg grating dynamic truck scale device and a system thereof, and belongs to the technical field of traffic transportation. The fiber bragg grating dynamic truck scale device comprises a fiber bragg grating weighing sensor, a weighing controller and a fiber bragg grating module modem. A plurality of fiber bragg grating weighing sensors form a fiber bragg grating weighing sensor group; covering a measurement range through a plurality of fiber bragg grating weighing sensor groups according to the width of the road surface; the fiber bragg grating weighing sensor converts the weight into a grating wavelength; a deformation digital signal is generated through calculation of the fiber bragg grating modem, and the weighing controller processes the data and then calculates the weight. The system is suitable for weighing and metering of dynamic vehicles for high-speed pre-detection, bridge overload control, axle load detection, over-limit and overload off-site law enforcement and the like; the device is high in reliability, free of maintenance and suitable for high-speed and low-speed weighing; the sensor can be installed within 3 hours, the sensor is not deformed after being rolled for 30 million times at least, the precision is not affected, and the sensor can work stably in extreme weather environments.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of transportation technology, in particular to a fiber grating dynamic truck scale device and system thereof. BACKGROUND

[0002] The phenomenon of overloading transportation on the highway is very common and serious. Overloading is very harmful to the road surface, and brings great safety hazards to the pedestrians and vehicles on the road. The harm mainly includes the following aspects. 1) Accelerating the damage of the highway pavement and increasing the cost of highway maintenance. The design and construction of the highway have a certain axle load standard. Overloading accelerates the damage of the pavement and shortens the service life. 2) Frequent traffic accidents. The safety factors such as stability, maneuverability and braking of the vehicle will be greatly reduced after overloading, which will lead to a sharp increase in the rate of traffic accidents, seriously threatening the safety of life and property. 3) Serious environmental pollution. Due to overloading, the engine is overloaded, and the exhaust smoke and noise are several times of the normal situation, which is obviously harmful to the natural and social environment. 4) Accelerating the damage of the vehicle. Overloading seriously damages the vehicle parts, shortens the period of secondary maintenance of the vehicle, speeds up the scrapping of the vehicle, and causes waste of resources.

[0003] The important equipment for road sensing is the dynamic weighing product. At present, the sensors commonly used for dynamic weighing mainly include inductive coil type sensor, piezoelectric type sensor and bending disc type sensor. These three types of sensors have some shortcomings in terms of principle, working performance and reliability, and the main problems are as follows. 1) The existing equipment and technology cannot simultaneously weigh the vehicle at high and low speeds. For example, the bending plate type, shaft group type and narrow strip type dynamic weighbridge based on the pressure resistance sensor has an error in measurement that is not acceptable when the speed of the measured vehicle is higher than 40 km / h, and the piezoelectric quartz type dynamic weighbridge also has the same error when the speed is lower than 40 km / h. 2) Low precision. For example, the measurement precision of the WIM system based on the bending disc type sensor is only 10%, and that based on the piezoelectric type sensor is only 15%. 3) Difficult to lay and high cost. The above-mentioned sensors have strict design and device requirements in the actual application of the WIM system, and the length of the hardened road surface is usually 25-30 meters, which has high laying cost and long period of loss. 4) Poor anti-interference ability and easy to be affected by the environment. The inductive coil type and piezoelectric type sensors are easily affected by the earth's magnetic field and have low anti-electromagnetic interference ability. In addition, temperature and different laying methods will also affect the WIM system. 5) Cannot work in harsh environment and has short service life.

[0004] Given the shortcomings of the aforementioned sensors, and in order to adapt to the rapidly developing transportation industry and ensure road traffic safety, scientists both domestically and internationally have recently begun research and development of fiber Bragg grating (FBG) sensors. Compared to traditional sensors, FBG sensors offer advantages such as resistance to electromagnetic interference, corrosion resistance, electrical insulation, intrinsic safety, high sensitivity, small size, light weight, variable shape, and ease of multiplexing into networks. Summary of the Invention

[0005] The purpose of this invention is to provide a fiber optic grating dynamic truck scale device and system thereof.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The fiber Bragg grating dynamic truck scale device includes: fiber Bragg grating load cells, a weighing controller, and a fiber Bragg grating module modem; it consists of several fiber Bragg grating load cells forming a fiber Bragg grating load cell group; the measurement range is covered by multiple fiber Bragg grating load cell groups according to the road width; the fiber Bragg grating load cells convert the weight into grating wavelength; the fiber Bragg grating modem calculates the deformation digital signal, and the weighing controller processes the data to calculate the weight.

[0008] In some embodiments, the fiber Bragg grating load cell includes: a weighing plate and a fiber Bragg grating sensor encapsulated within the weighing plate;

[0009] The weighing plate is made of carbon fiber; it is a composite material made of carbon fiber and resin.

[0010] In some embodiments, the weighing plate is mounted on a mounting base; the mounting base is fixed in a road groove and filled with epoxy resin potting compound; the top surface of the weighing plate is flush with the road surface.

[0011] In some embodiments, the mounting base comprises: a base plate, side plates extending along the length of the base plate and located on both sides, and end sealing plates sealing both ends of the side plates; the two side plates are arranged in parallel and have slots on opposite sides; the weighing plate has matching notches on both sides corresponding to the slots; the weighing plate is inserted into and assembled on the mounting base from one end; the side plates and the two sides of the base plate retain edges to form a buried shape.

[0012] In some embodiments, the road surface groove is further provided with a support structure and a tensioning structure; the tops of each support structure are on the same plane to support the mounting base; each tensioning structure is connected to the mounting base to pull down and fix the mounting base.

[0013] The fiber Bragg grating dynamic truck scale system includes: a signal acquisition and transmission module, a data processing module, a display and control module, and an external platform module. The signal acquisition and transmission module acquires and transmits data from the fiber Bragg grating weighing sensor; the data processing module performs calculations on the data; the display and control module provides operation control and a display interface; and the external platform module outputs data in the required format.

[0014] Compared with the prior art, the present invention provides a fiber optic grating dynamic truck scale device and system, which has the following beneficial effects.

[0015] 1. This invention is applicable to the weighing and measurement of dynamic vehicles, such as those used for high-speed pre-inspection, bridge overload control, axle load detection, and off-site enforcement of overload and oversize vehicles.

[0016] 2. This invention is highly reliable, maintenance-free, and adaptable to high and low speed weighing; it can be installed in 3 hours, and it can withstand at least 30 million rolling cycles without deformation and with stable accuracy, and it can work stably in extreme weather environments.

[0017] Other advantages, objectives and features of the invention will be set forth in part in the description which follows; and in part will be apparent to those skilled in the art upon examination of the following description; or may be learned from practice of the invention. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of the present invention.

[0019] Figure 2 This is a schematic diagram of the construction state of the present invention.

[0020] Figure 3 This is a top view schematic diagram of the construction state of the present invention.

[0021] Figure 4 This is a schematic diagram showing the installation status of the base.

[0022] Figure 5 for Figure 4 A magnified structural diagram of point A in the middle.

[0023] Figure 6 This is a schematic diagram of the mounting base.

[0024] Figure 7 This is a top view of the mounting base.

[0025] Figure 8 This is a schematic diagram of the lower structure of the mounting base.

[0026] Figure 9 This is a schematic diagram of the end structure of the mounting base.

[0027] Figure 10This is a schematic diagram of a partial explosion.

[0028] Figure 11 This is a schematic diagram of the explosion state of the part where the base is installed.

[0029] Figure 12 This is a schematic diagram of the swing tensioner.

[0030] Figure 13 This is a schematic diagram of a fiber Bragg grating weighing sensor.

[0031] Figure 14 Photograph of a fiber Bragg grating load cell.

[0032] Figure 15 A photo of the weighing plate.

[0033] Figure 16 This is a schematic diagram showing the installation status of the weighing plate and mounting base.

[0034] Figure 17 This is a perspective view of a fiber Bragg grating.

[0035] Figure 18 A photo of the test site.

[0036] Figure 19 Photograph of a fiber Bragg grating module modem (prototype).

[0037] Figure 20 This is a photo of the inside of the computer case.

[0038] Figure 21 This is a photo of the exterior of the computer case.

[0039] Figure 22 Photo 1 shows the construction support structure.

[0040] Figure 23 Photo 2 shows the construction support structure.

[0041] Figure 24 This is a photograph showing the completed installation of the present invention.

[0042] Figure 25 A schematic diagram showing the positioning of the supporting and tensioning structures.

[0043] Figure 26 This is a schematic diagram of the cross-sectional structure.

[0044] Figure 27 This is a schematic diagram of the installation area.

[0045] Figure 28 This is a photo of the work interface.

[0046] Figure 29 This is a configuration interface diagram.

[0047] Figure 30 This is the data query interface.

[0048] In the diagram: 1. Weighing plate; 2. Mounting base; 21. Base plate; 22. Side clamping plate; 23. End sealing plate; 221. Reinforcing block; 3. Support structure; 31. Positioning ring; 32. Threaded hole; 33. Fine adjustment bolt; 34. Injection hole; 4. Tensioning structure; 41. Lifting eye bolt; 42. Threaded seat; 5. Swinging tensioning component; 51. Strip plate; 52. Shaft; 53. Pin; 6. Arc-shaped opening groove; 7. Cable passage hole; 8. Glue injection hole; 81. Plug; 9. Active leveling screw. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0050] Reference Figures 1-30 The fiber Bragg grating dynamic truck scale device includes: fiber Bragg grating load cells, a weighing controller, and a fiber Bragg grating module modem. It consists of several fiber Bragg grating load cells forming a fiber Bragg grating load cell group; the measurement range is covered by the fiber Bragg grating load cells according to the road width.

[0051] like Figure 1 As shown, during operation, the vehicle's axles sequentially pass over a group of fiber optic load cells (FOCCs) installed across the road surface. The FOCCs convert the weight of the axles into FOCC wavelengths, which are then transmitted via optical fiber to the weighing controller. The FOCC modem decodes the data to generate a digital deformation signal. The weighing controller processes the data, segments adjacent axles or axle groups, and calculates their weights. After the last segment of the vehicle passes the weighing platform and its weight is calculated, the weights of all segments are added together to obtain the total vehicle weight. This device is suitable for weighing and measuring dynamic vehicles used in highway pre-inspection, bridge overload control, axle load detection, and off-site enforcement of overload and oversize regulations.

[0052] like Figures 2-11 As shown in Figures 13-15; the fiber Bragg grating load cell includes: a weighing plate 1 and a fiber Bragg grating sensor encapsulated within the weighing plate 1.

[0053] This technical approach uses direct measurement of the deformation of the weighing plate 1, so the weighing body material needs to have a rolling and bending resistance of no less than 10 million cycles per year, good resilience, a very small coefficient of thermal expansion, and a controllable modulus of elasticity. Conventional materials are difficult to meet these requirements.

[0054] After research, demonstration, and testing, it was found that the weighing plate 1 is made of carbon fiber plate; it is made of carbon fiber and resin matrix material composite, which significantly improves the load-bearing capacity and stability of the weighing body.

[0055] Traditional shaft-type weighing instruments require digging a pit nearly one meter deep, and the concrete curing process takes more than half a month; such as Figure 2 , 3 As shown in Figure 23, this device only requires opening a groove in the road surface (e.g., 40 cm wide and 8 cm deep) and filling it with epoxy resin slurry. It can be installed in 3 hours and traffic can be restored in 6 hours.

[0056] The core advantage of this application is accurate weighing across the entire vehicle speed range. Traditional weighing equipment requires high vehicle speeds, otherwise the accuracy will drop significantly. This device achieves accurate weighing across the entire vehicle speed range from 0.5 km / h to 100 km / h. The fiber optic grating acts like a precise nerve ending, capturing the subtle deformations of the vehicle during driving. Combined with the carbon fiber composite weighing plate, it will not deform even after a minimum of 30 million crushing cycles.

[0057] The maintenance-free feature allows maintenance personnel to say goodbye to "emergency repairs in rainy weather." Traditional equipment's electronic sensors are susceptible to water accumulation and electromagnetic interference, requiring multiple maintenance checks each year. In contrast, the fully enclosed, sealed fiber optic meter operates stably in extreme weather environments, with 30 million rolls over 3 years requiring no maintenance. Tests on the Yahe Expressway showed that even during heavy rain and snowstorms, the metering accuracy remained stable.

[0058] like Figure 13 As shown, fiber Bragg grating sensors have advantages such as being passive, having strong anti-interference capabilities, and high deformation accuracy, but reliable packaging of the fiber Bragg grating is required; packaging has always been a challenge for its widespread application. Currently, in stress-strain applications, metal strain gauges are generally used for packaging, but this metal strain gauge packaging method is not suitable for dynamic weighing applications with high sampling rates and high resilience.

[0059] like Figures 13-16 As shown, in this technical approach, the fiber Bragg grating sensor is encapsulated within a carbon fiber composite weighing plate 1 to improve the sensor's sensitivity and durability.

[0060] Fiber Bragg grating (FBG) sensors change the wavelength of reflected light according to changes in ambient temperature and strain. By exposing a small segment of photosensitive fiber to a periodically distributed light wave using holographic interferometry or phase masking, the fiber's refractive index changes according to the intensity of the incident light. This periodic change in refractive index is called a fiber Bragg grating. When a broad-spectrum beam of light is propagated to a fiber Bragg grating, each segment of fiber, after its refractive index is altered, reflects only a specific wavelength of light, called the Bragg wavelength. This characteristic allows the fiber Bragg grating to reflect only a specific wavelength of light, while other wavelengths are propagated. The Bragg condition formula is λ. B =2neffΛ; where, λ BΛ is the Bragg wavelength, neff is the effective refractive index of the fiber core, and Λ is the spacing length between gratings, called the grating period. Because the Bragg wavelength is a function of the spacing length between gratings, fiber Bragg gratings can be manufactured with different Bragg wavelengths, thus enabling the use of different fiber Bragg gratings to reflect light waves of specific wavelengths.

[0061] See Figure 16 Perspective view of a fiber Bragg grating.

[0062] Strain effect: Changing the grating period Λ and the effective refractive index neff leads to an increase in the Bragg wavelength λ. B Wavelength drift; the formula relating wavelength drift to strain is: Δλ=λB(1-pe)ε; Δλ is the wavelength drift, pe is the optical elastic coefficient of the fiber, and ε is the strain; the linear relationship is the key basis for measuring strain and achieving weight measurement.

[0063] Changes in strain and temperature simultaneously affect the effective refractive index *neff* and the grating period *Λ* of a fiber Bragg grating, resulting in a change in the wavelength of the emitted light. The variation of the reflected wavelength of a fiber Bragg grating with strain and temperature can be approximated as follows: Δλ represents the change in reflected wavelength, and λ0 is the initial reflected wavelength. (1-p) e )×ε represents the effect of strain variation on the reflected wavelength; p e α is the strain optics sensitivity coefficient, and ε is the effect of strain on the grating. Λ +α n α × ΔT represents the effect of temperature change on wavelength. Λ It is the coefficient of thermal expansion, α n It is the temperature optical sensitivity coefficient; α Λ This illustrates the effect of temperature changes on the refractive index of light. n This reflects the change in grating period caused by the same temperature change. The stress-strain characteristics of the FBG sensor are: measurement accuracy ±1 μm, temperature measurement accuracy ±0.1 degrees Celsius.

[0064] The displacement of the mass block (vehicle) is calculated using fiber Bragg grating signals to obtain weight data; the elastic modulus is calculated by determining the structural length, width, and thickness, and wavelength drift caused by temperature is compensated for to obtain velocity data; combined with the sensing differences of different parts of the fiber Bragg grating sensing unit, the axle count is calculated; and the tire count is calculated using a model corresponding to the contact surface and pressure values. The management system integrates weight, speed, axle, and tire data, transmitting them to the management platform for intuitive display, facilitating daily use and data archiving.

[0065] In some embodiments, the weighing controller is housed inside the chassis.

[0066] like Figures 19-21 As shown; the rear of the chassis has a communication interface for connecting fiber optic access, network access, external monitors, etc.; the front of the chassis has a display screen (which can be a touch screen), and a pull-out keyboard is located below. Correspondingly, the fiber Bragg grating module modem is installed inside the chassis or externally connected to the chassis.

[0067] In some embodiments, the weighing plate 1 is mounted on the mounting base 2; the mounting base 2 is fixed in a road surface groove and filled with epoxy resin potting compound. Epoxy resin potting compound is a high-adhesion, weather-resistant road surface filling material that ensures stable installation and long-term operation of the equipment.

[0068] like Figure 24 , 26 As shown; the top surface of weighing plate 1 is flush with the road surface, which satisfies the measurement requirements and does not affect traffic.

[0069] In some embodiments, the mounting base 2 consists of a base plate 21, side plates 22 extending along the length of the base plate 21 and located on both sides, and end sealing plates 23 sealing both ends of the side plates 22.

[0070] It is understandable that the installation of weighing plate 1 should be stable and reliable, and should not affect weighing deformation; a snap-fit ​​design is preferred. Specifically, such as... Figure 11 As shown; two side plates 22 are arranged in parallel, and slots are opened on opposite sides; the weighing plate 1 has matching notches on both sides corresponding to the slots; the weighing plate 1 is inserted (pushed in) and assembled on the mounting base 2 from one end; it is supported by both sides, and the lower end is suspended, so it can deform when weighing.

[0071] It should be noted that the deformation during weighing is very small; there is a certain gap (very small) between the end sealing plates 23 at both ends and the bottom of the weighing plate 1, which does not affect the deformation of the weighing plate 1 during operation.

[0072] Furthermore, the side plates 22 and the bottom plate 21 retain edges on both sides to form a recessed shape (that is, to form a structure that is smaller at the top and larger at the bottom), which has stronger pull-out resistance and a more stable installation shape.

[0073] Preferably, the outer side of the side plate 22 is provided with multiple reinforcing blocks 221 to improve the overall strength and load-bearing capacity.

[0074] It should be noted that the overall thickness of the mounting base 2 and the weighing plate 1 can be controlled within 5 cm; the thickness of the weighing plate 1 is about 1 cm; the mounting base 2 is made of metal and is about 3 cm thick; and the corresponding road surface groove is 8 cm wide.

[0075] It is understandable that the base plate 21, side plate 22, end sealing plate 23, and weighing plate 1 form a cavity, which is filled with adhesive; the lower end of the base plate 21 has an adhesive injection hole 8 that connects to the cavity, and a plug 81 is installed thereon.

[0076] like Figures 8-10 As shown; the side plate 22 and the base plate 21 are an integral structure; the end sealing plate 23 is assembled after the weighing plate 1 is installed in place; as shown Figure 9 As shown, the end sealing plate 23 is assembled with bolts; preferably, the ends of the bottom plate 21 and the side clamping plate 22 are provided with grooves, and the end sealing plate 23 is inserted into the grooves; and the end sealing plate 23 is provided with grooves for the matching bolts, so that the bolts do not protrude outwards, so as to avoid affecting the adjacent installation between the two sets.

[0077] In addition, it is important to note that precision control is required for road surface grooving.

[0078] Preferably, the standard for the flatness of the tank bottom is: the difference between the highest and lowest points of the tank bottom does not exceed 5mm.

[0079] In some embodiments, a support structure 3 and a tensioning structure 4 are also provided in the road surface groove.

[0080] The tops of each support structure 3 are on the same plane, supporting the mounting base 2.

[0081] At the same time, each tensioning structure 4 is connected to the mounting base 2 to pull down and fix the mounting base 2.

[0082] Preferably, the support structure 3 and the tensioning structure 4 are expansion screws. The top of the expansion screw of the support structure 3 is cut and placed on the same plane to form a bottom support for the mounting base 2; the expansion screw of the tensioning structure 4 is connected to the mounting base 2 by steel wire, iron wire or other connecting parts to form a downward pulling force.

[0083] like Figure 22 , 23 As shown in Figure 25; Position the expansion screws according to high-precision standard points, and use a positioning ruler and gauge to drill holes; simultaneously, select expansion screws according to the groove depth. For example, when using φ12 screws, ensure that the expansion screws extend 45-50mm above the bottom of the groove. After installing the expansion screws for the support structure, level the top surface. Use a leveling ruler and angle grinder to horizontally cut the expansion screws, ensuring all expansion screws are within the installation horizontal plane. Required standard: Expansion screw height error ±0.5mm.

[0084] For the expansion screws of tension structure 4, the top surface accuracy is not required, but the installation position must be precise.

[0085] Another point to note is that after installing the expansion bolts, the grooved surface of the road surface should be cleaned and dried.

[0086] Clean the tank with water to remove debris, and use a medium-pressure blower to remove surface moisture and dust. After surface drying, use a heat gun to repeatedly heat the tank surface to 120-150°C for 3 minutes to ensure it is completely dry, preventing cracking. After drying, use a medium-pressure blower again to remove dust. Cleaning standard: Wiping the tank with a dark towel or gloves should not leave obvious white stains. Humidity standard: Moisture content less than 5%.

[0087] In some embodiments, such as Figure 8 As shown, the lower end of the support structure 3 is provided with a positioning ring 31 corresponding to the support structure 3, so as to facilitate quick alignment and further control the accuracy.

[0088] Furthermore, the mounting base 2 has a through threaded hole 32 corresponding to the positioning ring 31, and is equipped with a fine-adjusting bolt 33; the fine-adjusting bolt 33 passes through the positioning ring 31 and presses against the support structure 3.

[0089] like Figure 5 As shown, higher precision leveling is achieved through the fine-tuning bolt 33 in conjunction with the support structure 3. It can be understood that the level is initially controlled by the support structure 3, and then adjusted by the fine-tuning bolt 33. The thread pitch of the fine-tuning bolt 33 is set to be smaller to ensure adjustment accuracy.

[0090] Furthermore, an elongated injection hole 34 is coaxially provided at the location of the threaded hole 32; after leveling, a quick-setting gel or other curing material is injected into the hole 34 to further ensure stability and accuracy.

[0091] Preferably, the injection hole 34 has a tapered shape that is larger at the top and smaller at the bottom, making it easier to discharge materials and less likely to overflow.

[0092] It should be noted that the support structure 3 does not necessarily completely block the positioning ring 31, and some of the material fed into the injection hole 34 will flow down; it is preferable to use a curing material with a certain consistency; here it is mainly to fix the fine-tuning bolt 33 and assist in bonding the support structure 3, some curing material is enough, it does not need to be full.

[0093] In some embodiments, the mounting base 2 is also threaded with a plurality of active leveling screws 9 on both sides.

[0094] like Figure 4 , 6 As shown in Figure 8, the distance below can be pre-controlled by the active leveling screw 9; and it can also assist in support and adjustment, further improving the overall accuracy and reliability.

[0095] It should be noted that multiple threaded holes are provided on the mounting base 2, all of which can be used to install the active leveling screw 9; in actual use, the active leveling screw 9 can be installed in the appropriate position as needed, or none of them can be installed.

[0096] In some embodiments, the side of the support structure 3 is provided with a ring structure corresponding to the tensioning structure 4 (the central axis of the control ring is kept as vertical as possible) to facilitate alignment, connection and other operations, making it more convenient.

[0097] Preferably, the ring structure is a lifting eye bolt 41, which can also be adjusted appropriately. Correspondingly, a threaded seat 42 is fixedly provided on the side of the mounting base 2, and the lifting eye bolt 41 and the threaded seat 42 are detachably assembled and disassembled.

[0098] like Figure 5 As shown; the inner diameter of the eye bolt 41 is larger than the outer diameter of the expansion bolt shank of the support structure 3; the shank of the expansion bolt passes through the eye bolt 41, and the tightening operation can be performed by assembling the washer and nut.

[0099] Understandably, other connection methods such as steel wire or copper wire tensioning can also be chosen (in this case, expansion hooks are preferred, such as...). Figure 26 (as shown); Alternatively, a pre-drilled plate can be used on the side of the mounting base 2 to directly fit the expansion screw (in this case, it is preferable to use an integral or fixedly welded plate with an elongated hole).

[0100] In some embodiments, a swing tensioner 5 is rotatably provided on both sides of one end of the mounting base 2, and an arc-shaped opening groove 6 is provided on both sides of the other end to cooperate with it. When installed adjacent to each other, the swing tensioner 5 of one mounting base 2 is engaged into the arc-shaped opening groove 6 of the other mounting base 2, bringing the two closer together and avoiding adverse situations such as excessive gaps. Moreover, the arc-shaped opening groove 6 cooperates with the swing tensioner 5 to gradually tighten, resulting in a better effect.

[0101] like Figure 6 , 10 As shown in Figure 12, the swing tensioning member 5 consists of two parallel strip plates 51 and two shafts 52 fixedly connected to both ends of the strip plates 51.

[0102] During installation, after two adjacent mounting bases 2 are placed, the swing tensioner 5 of the first mounting base 2 is rotated until it is engaged with the arc-shaped opening groove 6 of the second mounting base 2; the two mounting bases 2 are tightly connected together by the gradually changing tension point during the rotation process.

[0103] It should be noted that the thickness between the two strip plates 51 matches the thickness of the base plate 21; that is, the two strip plates 51 are tightly fitted to the base plate 21; and under tension, the flatness of the two is also limited to a certain extent.

[0104] Furthermore, a pin 53 is inserted through the strip plate 51; a pin hole is correspondingly opened on the end of the mounting base 2 away from the swing tensioner 5 to prevent swinging after it is in place.

[0105] like Figure 3 , 4 As shown in Figure 12; after the swing tensioner 5 is rotated into place, the pin 53 is passed through the strip plate 51, the mounting base 2, and the strip plate 51 in sequence to lock the position of the swing tensioner 5 and prevent it from swinging.

[0106] In some embodiments, the mounting base 2 has a cable pass-through hole 7 for optical fiber to pass through.

[0107] It should be noted that the wire hole 7 should be opened on the side or bottom surface (the ends need to be connected to each other, which is inconvenient for wiring); preferably, the wire hole 7 is opened on the side of the mounting base 2 (on the side plate 22).

[0108] It should be noted that when assembling the weighing plate 1, the optical fiber is first led out from the cable passage hole 7; then, the weighing plate 1 is pushed into place; then, the optical fiber is pulled outward to make it in a suitable internal and external state; then, the end caps 23 at both ends are assembled; then, the sealing plug 81 is opened and glue is injected inside; after the glue injection is completed, the sealing plug 81 is installed again; the diameter of the cable passage hole 7 should be larger than that of the optical fiber, and various means (such as setting glue plugs in the cable passage hole 7) are used to seal it during glue injection (it is not necessary to seal it completely).

[0109] Furthermore, the fiber optic cable of the fiber optic load cell extends outward and is then bound to a rigid guide.

[0110] Preferably, a rigid guide such as iron wire or steel wire is used and placed at the bottom center of the road surface groove; after each set of fiber optic load cells is installed, its optical fibers are tied to the rigid guide accordingly.

[0111] like Figure 25 As shown, a fiber optic cable is pre-stretched within a groove in the ground to secure the fiber optic cable. The position of the fiber optic cable is not particularly restricted (preferably in the center for easier cable routing).

[0112] In addition, special attention should be paid to the routing of optical fibers and prevention of fiber damage during installation; when optical fiber cables need to bend, the bending radius must not be less than 50mm; during construction and use, it is strictly forbidden to pull the optical fibers and fiber connectors forcefully.

[0113] In addition, pay attention to the protection of fiber optic connectors; always keep the fiber optic connectors with protective caps before wiring; if the ceramic core of the fiber optic connector is found to be dirty, clean it promptly with a cotton ball soaked in anhydrous alcohol.

[0114] In some embodiments, the interface of the fiber Bragg grating load cell is FC / APC*2.

[0115] Furthermore, based on the standard highway specifications in China and the applicant's many years of industry experience, the dimensions of a set of fiber optic load cells are set to 905mm (length) * 330mm (width) * 50mm (height).

[0116] Generally, the milling volume of the sensor mounting slot should be: length (coverage width of the detection lane) N meters × width (390mm) × depth (80mm). For example, when the lane width is 3900mm, according to the principle of covering the entire lane as much as possible, there are two sensor combination schemes: (1) For lanes with hard barriers: 4 sets of 905mm specification sensors can be selected, that is, the length of the paved sensor is 3620mm, and 280mm is left at both ends; (2) For open lanes: 5 sets of 905mm specification sensors can be selected, that is, the length of the paved sensor is 4525mm, which can extend 700mm beyond the lane to the open space at both ends.

[0117] like Figure 27 (Schematic diagram, location not precisely shown) This is a schematic diagram of the installation area; the optical fibers of each group of sensors are led out from the side and converge, and the cabinets are set up by the roadside.

[0118] The construction steps for this device are as follows.

[0119] Step 1: Place the sensor; place the sensor (mounting base + weighing plate) on the pre-installed expansion screws in the installation sequence.

[0120] Standard: The upper plane of the sensor should be flush with the road surface, and the horizontal adjustment error should not exceed ±0.5mm; the sensor should be located in the center of the groove, and the distance between the front, back, left and right edges of the sensor and the groove wall should be equal, with an error not exceeding ±2mm.

[0121] Step 2: Fiber optic cable laying; Lay the sensor communication fiber optic cable along the steel wire at the center of the bottom of the trench, and use cable ties to bind the fiber optic cable to the central steel wire.

[0122] Note: For each sensor installation, the optical fiber needs to be bundled and tied to the steel wire. The bending diameter of the optical fiber cable should not be less than 50mm. When running the optical fiber through the conduit, the optical fiber connector should be protected with tape beforehand.

[0123] This device also includes several supporting peripherals, such as a snapshot camera, a ground loop coil, and a weight display screen. The parameters of each peripheral are configured through the main menu; for example, configuring the peripheral's IP address, saving settings, configuring sensor parameters, weight coefficients, and coil parameters. These peripherals are common components in the industry and will not be described in detail here. Figure 29 , 30The image shown is a diagram of the configuration interface and a diagram of the query interface.

[0124] The speed measurement of this truck scale can be calculated by measuring the time it takes for a vehicle to pass through the coil and the distance between the coil centers. After adjusting the distance parameters, several tests are required to take the average value. Different models of vehicles need to be tested to adjust the sensitivity of the vehicle detector in order to accurately detect the vehicle speed. When applied to high-speed (greater than 40km / h) weighing and speed measurement, the distance between the ground inductive coils must be greater than 3.0 meters.

[0125] The fiber Bragg grating dynamic truck scale system includes: a signal acquisition and transmission module, a data processing module, a display and control module, and an external platform module. The signal acquisition and transmission module acquires and transmits data from the fiber Bragg grating weighing sensor; the data processing module performs calculations on the data; the display and control module provides operation control and a display interface; and the external platform module outputs data in the required format.

[0126] like Figure 27 The image shown is the system operation interface.

[0127] The working principle of this system is as follows: signal acquisition → preprocessing → key parameter calculation → axle load conversion → total weight calculation. Based on the strain response characteristics of fiber optic grating sensors and combined with the vehicle's dynamic driving status, the wavelength drift signal is converted into vehicle weight; and the mathematical relationship between vehicle speed, wheelbase, and axle load can be calculated.

[0128] Fiber Bragg grating load cell

[0129] Installation location: On the load-bearing structure of the weighing area;

[0130] Function: It senses the strain caused by vehicle tire pressure, resulting in wavelength drift;

[0131] Performance requirements: high strain sensitivity, good linearity, and stability.

[0132] Signal acquisition and transmission module

[0133] Function: Real-time acquisition of wavelength drift signals and transmission to the data processing module;

[0134] Signal conversion: Wavelength-shifted signal → Electrical signal (using the properties of reflected light);

[0135] Signal acquisition: Data acquisition card or specialized equipment for high-speed, high-precision sampling;

[0136] Signal transmission: wired or wireless.

[0137] Data processing module

[0138] Functions: Signal preprocessing, key parameter calculation, axle load conversion, total weight calculation, etc.

[0139] Operation method: Specialized software algorithm extracts useful information and calculates vehicle weight.

[0140] Display and Control Module

[0141] Functions: Displays weighing results and related parameters, and provides an operation interface;

[0142] Operation control: setting weighing parameters, starting and stopping weighing, etc.;

[0143] Display interface: An intuitive graphical interface for easy access to information.

[0144] The signal acquisition and transmission module acquires the wavelength drift signal of the fiber Bragg grating and converts the wavelength drift signal into an electrical signal.

[0145] Signal acquisition: Obtain the wavelength drift signal of the fiber Bragg grating;

[0146] Pressure transmission: Tire pressure → Load-bearing structure → Fiber Bragg grating load cell

[0147] Strain and wavelength drift: The greater the strain, the greater the wavelength drift Δλ.

[0148] Signal conversion: The photoelectric conversion module converts the wavelength-shifted signal into an electrical signal;

[0149] Signal amplification: Amplifying weak electrical signals;

[0150] Signal acquisition: Data acquisition equipment records signal changes and stores them in digital form.

[0151] The data processing module preprocesses the signal to eliminate interference and extract the effective signal.

[0152] Filtering: A low-pass filter is used, and a cutoff frequency is set to remove high-frequency noise; a temperature-compensated grating is used to calculate and subtract the wavelength shift caused by temperature; the temperature compensation formula is Δλ. temp =α temp ×ΔT;α temp Here, ΔT is the temperature coefficient, and ΔT is the temperature change.

[0153] Electromagnetic interference: Shielding measures (shielded cables, grounding) and digital filtering algorithms (median filtering, mean filtering) are employed.

[0154] Peak recognition

[0155] Objective: To accurately identify peak values ​​in a signal and record their occurrence times;

[0156] Commonly used algorithms: threshold method, derivative method;

[0157] Time difference record: The time difference Δt between adjacent peaks is used to calculate wheelbase and vehicle speed.

[0158] In some embodiments, the data processing module calculates the vehicle speed and tire width.

[0159] Methods for calculating vehicle speed:

[0160] Given: Sensor spacing L (pre-measured and determined) or standard wheelbase calibration; Calculation formula:

[0161] Multiple measurements are taken and averaged, and the sensor installation location and vehicle trajectory are corrected to improve accuracy.

[0162] Method for calculating tire width:

[0163] Method 1: Calculate by combining the peak duration in the signal with the vehicle speed; Calculation formula: w = vt; t is the pressure application time;

[0164] Method 2: Use a dedicated width sensor to directly obtain the tire width (using technologies such as laser and infrared).

[0165] In some embodiments, the data processing module performs axle load conversion; the method for calculating weight from wavelength drift is as follows.

[0166] Wavelength drift and strain relationship: Δλ=λB(1-pe)ε;

[0167] Strain-pressure relationship: ε = PE; P is pressure, E is elastic modulus.

[0168] Axle load calculation formula: W=v×k×Δλ×w;

[0169] W is the axle load; k is a proportionality coefficient related to sensor characteristics (strain sensitivity, elastic coefficient, etc.).

[0170] Static calibration determines the k value:

[0171] Under standard vehicle static pressure, record the wavelength drift Δλ0, actual axle load W0, and tire width w0; W0 = k × Δλ0 × w0 (considering other relationships when static vehicle speed V0 = 0), and solve for...

[0172] Total weight calculation: Add up the weights of each axle;

[0173] Calculation formula: W total =W1+W2+W3+W4; W1, W2, W3, and W4 are the axle loads of each axle.

[0174] Weighted average axle load correction is performed to check for reasonableness (to determine whether the total weight is within the reasonable load range, in order to improve accuracy).

[0175] In some embodiments, the data processing module calculates the mathematical relationship between vehicle speed and related parameters.

[0176] The data processing module calculates the relationship between vehicle speed and wheelbase;

[0177] Calculation formula: a ij =v×Δt ij ;a ij Δt is the wheelbase between axle i and axle j; v is the vehicle speed; Δt ij The time difference between the peak values ​​appearing when axle i and axle j pass the sensor.

[0178] Corrections are made to account for changes in vehicle driving conditions (acceleration, deceleration, etc.) to improve accuracy.

[0179] The data processing module calculates the relationship between vehicle speed and axle load;

[0180] Axle load calculation formula: W=v×k×Δλ×w;

[0181] W is the half-axle weight measured at time t; Δλ is the maximum wavelength drift of the FBG at time t; k is the proportionality coefficient related to the strain sensitivity of the FBG and the elastic coefficient of the rubber protective shell; w is the tire width measured at time t; v is the vehicle speed at time t when the tire passes the sensor.

[0182] Impact: Changes in vehicle speed cause changes in the contact time and pressure distribution between the tire and the sensor, affecting the wavelength drift and axle load calculation results.

[0183] The measurement results at different vehicle speeds are calibrated and corrected to improve accuracy.

[0184] In some embodiments, the core process of the data processing module is to infer the strain from the wavelength drift signal of the fiber optic grating and then combine it with vehicle dynamic parameters (vehicle speed, tire width, etc.) to convert it into a weight value.

[0185] Taking full account of the importance of static weighing calibration, the conversion factor k is used.

[0186] The importance of the conversion factor k: The accuracy of the k value directly affects the accuracy of axle load and gross weight calculations;

[0187] Static calibration method: Record the wavelength drift and actual axle load using a standard vehicle of known weight, and calculate the k-value; formula W0 represents the standard vehicle axle load, Δλ0 represents the corresponding wavelength drift, and w0 represents the tire width.

[0188] The necessity of periodic calibration should be fully considered; since sensor performance may change over time, periodic static calibration is required to ensure measurement accuracy.

[0189] This application provides an internationally leading weighing sensor, a weighing body based on composite materials, a new type of dynamic weighbridge with high reliability, maintenance-free operation, and adaptability to high and low speed weighing; and installation materials and processes that allow for installation and opening to traffic within 24 hours.

[0190] The research project on all-weather, full-speed fiber optic grating durable truck scale, developed by the research team over many years, moved out of the laboratory in July 2023. Three test sites were established: near the intersection of National Highway 104 and Provincial Highway 239 in Liyang, Jiangsu; Goulin toll station on the Erguang Expressway in Nanyang, Henan; and Zheshan overload station on National Highway 312 in Zhenping, Nanyang, Henan. The team also organized the research and development and application of fiber optic grating sensing weighing systems and participated in the formulation of one group standard.

[0191] Technical parameters:

[0192] Implementation standard: GB / T21296.1-2020

[0193] Maximum axle weighing capacity: 40t (40t is a typical value for one axle with 4 tires, the actual value is the number of tires * 10t)

[0194] Minimum shaft weighing capacity: 1t

[0195] Graduation value: 100kg

[0196] Accuracy class of vehicle gross weight: Level 5

[0197] Accuracy class for single-axis or shaft group loads: Class F

[0198] Maximum operating speed: 100km / h, minimum operating speed: 0.5km / h

[0199] Number of sensor channels: 16.

[0200] This device underwent type evaluation by the National Automatic Weighing Instrument Type Evaluation Laboratory (Shandong); dynamic testing was conducted in Shuangzhuyuan Village, Yahe Expressway, Huangludian Town, Nanzhao County, Nanyang City, Henan Province (Nanyang direction). The error accuracy is ±2.5%, and it can be widely used for dynamic weighing, overload warning, and multi-axis detection in rigid and flexible highways, overload control stations, highway checkpoints, transportation hubs, bridges, and tunnels.

[0201] Prototype model, specifications, accuracy class / maximum permissible error / uncertainty and serial number.

[0202]

[0203] Key components and materials.

[0204]

[0205] The expected economic benefits of this application are mainly reflected in the following three aspects:

[0206] 1. Reduce highway maintenance costs: Traditional weight measurement equipment suffers from inaccurate measurements and requires frequent maintenance and replacement, leading to continuously increasing highway maintenance costs. This application utilizes fiber optic grating technology to achieve accurate vehicle weight measurement, effectively avoiding factors that cause highway damage and reducing maintenance costs. According to relevant research, the application of fiber optic grating technology in highway weighing stations can save each prefecture-level city millions or even tens of millions of yuan in highway maintenance costs annually.

[0207] 2. Accident Prevention: Overloaded trucks on highways can lead to road surface wear and rollovers, causing significant economic and personal losses. Fiber Bragg grating (FBG) technology can monitor and control truck overloading in real time, preventing overloading and thus reducing traffic accident rates and economic losses. Research indicates that the application of FBG technology at highway truck weighing stations can prevent dozens of traffic accidents annually in each prefecture-level city, saving millions of yuan in economic losses.

[0208] 3. New industrialization revenue from new projects and upgrades to existing equipment: Each prefecture-level city (second-tier city) has a budget of approximately 50 million yuan for off-site enforcement and dynamic weighbridges at overload control stations and road checkpoints. Based on 293 prefecture-level cities nationwide, the estimated annual incremental demand is over 10 billion yuan. Demand for upgrading existing equipment: Calculated based on a five-year replacement cycle for existing equipment, this is approximately 2 billion yuan.

[0209] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0210] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A fiber optic grating dynamic truck scale device, characterized in that, include: Fiber Bragg grating load cells, load controllers, fiber Bragg grating module modems; A fiber Bragg grating load cell group is composed of several fiber Bragg grating load cells; the measurement range is covered by multiple fiber Bragg grating load cell groups according to the road width; The fiber Bragg grating load cell converts weight into grating wavelength; the fiber Bragg grating modem then generates a deformation digital signal, and the load controller processes the data to calculate the weight.

2. The fiber optic grating dynamic truck scale device according to claim 1, characterized in that, The fiber Bragg grating load cell includes: a weighing plate (1) and a fiber Bragg grating sensor encapsulated in the weighing plate (1); The weighing plate (1) is made of carbon fiber plate; it is made of carbon fiber and resin matrix material composite.

3. The fiber optic grating dynamic truck scale device according to claim 2, characterized in that, The weighing plate (1) is assembled on the mounting base (2); the mounting base (2) is fixed in the road groove and filled with epoxy resin potting compound; the top surface of the weighing plate (1) is flush with the road surface.

4. The fiber optic grating dynamic truck scale device according to claim 3, characterized in that, The mounting base (2) consists of: a base plate (21), side plates (22) extending along the length of the base plate (21) and located on both sides, and end sealing plates (23) sealing both ends of the side plates (22); Two side plates (22) are arranged in parallel, and slots are provided on opposite sides; the weighing plate (1) has notches on both sides corresponding to the slots; the weighing plate (1) is inserted into and assembled on the mounting base (2) from one end; The side plate (22) and the bottom plate (21) retain their edges on both sides to form a buried shape.

5. The fiber optic grating dynamic truck scale device according to claim 3, characterized in that, The mounting base (2) has a wire hole (7) on its side; the fiber optic cable of the fiber optic grating weighing sensor extends outward and is tied to a rigid guide.

6. The fiber optic grating dynamic truck scale device according to claim 3, characterized in that, The road surface groove is also provided with a support structure (3) and a tensioning structure (4); The tops of each support structure (3) are on the same plane, supporting the mounting base (2); Each tensioning structure (4) is connected to the mounting base (2) to pull down and fix the mounting base (2).

7. The fiber optic grating dynamic truck scale device according to claim 6, characterized in that, The lower end of the mounting base (2) is provided with a positioning ring (31) corresponding to the support structure (3); the mounting base (2) is provided with a through threaded hole (32) corresponding to the positioning ring (31), and is equipped with a fine adjustment bolt (33); the fine adjustment bolt (33) passes through the positioning ring (31) and presses against the support structure (3).

8. The fiber optic grating dynamic truck scale device according to claim 4, characterized in that, The mounting base (2) has swing tensioning members (5) rotatably arranged on both sides of one end, and arc-shaped opening slots (6) are opened on both sides of the other end; The swing tensioning member (5) consists of two parallel strip plates (51) and shafts (52) that connect the two ends of the strip plates (51) respectively. A pin (53) is inserted through the strip plate (51); a pin hole is opened at the end of the mounting base (2) away from the swing tensioner (5).

9. A fiber optic grating dynamic truck scale system, characterized in that, The fiber Bragg grating dynamic truck scale device according to any one of claims 1-8; comprising: a signal acquisition and transmission module, a data processing module, a display and control module, and an external platform module; The signal acquisition and transmission module acquires and transmits data from the fiber Bragg grating weighing sensor; the data processing module performs calculations on the data; the display and control module provides operation control and display interface; and the external platform module outputs data in the required format.

10. The fiber optic grating dynamic truck scale system according to claim 9, characterized in that, The data processing module performs axle load conversion; the method for calculating weight from wavelength drift is as follows: Wavelength drift and strain relationship: Δλ=λB(1-pe)ε; Strain-pressure relationship: ε = PE; P is pressure, E is elastic modulus; Axle load calculation formula: W=v×k×Δλ×w; W represents the axle load; k is a proportionality coefficient related to the sensor characteristics; the value of k is determined by static calibration.

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