Device and method capable of monitoring contact state of tire bead in real time

Abstract

The invention relates to a device and method capable of monitoring the contact state of a tire bead in real time, and relates to the technical field of wheels, and the device comprises one or more sensor modules arranged on a rim; the sensor module comprises a plurality of interdigital capacitive MEMS acoustic emission sensors which are arranged along the edge, close to one side of the seam allowance, of any radial section of the rim, and the monitoring direction is perpendicular to the surface of the rim. According to the method, the bottleneck of a traditional monitoring method is broken through, the real-time dynamic displacement curve of the joint of the seam allowance and the rim can be monitored in real time based on the interdigital capacitive MEMS acoustic emission sensor under the working conditions of static inflation, static load and rolling of the tire, and whether the seam allowance slides or is dislocated abnormally or not is monitored. Key information is provided for optimization of the seam allowance curve, the seam allowance shape better conforming to mechanical distribution can be designed, the risk of fatigue damage is reduced, the durability and reliability of the tire seam allowance part are improved, the service life of a tire is prolonged, and the safety of a vehicle is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of wheels, and particularly to a device and method for real-time monitoring of the contact state of a tire bead. Background Art

[0002] The dynamic fitting state between the tire bead and the rim has a decisive impact on vehicle safety and tire life. Due to the complex stress distribution, frequent dynamic loads, differences in material properties, and environmental factors, the contact surface between the tire bead and the rim becomes a key area prone to fatigue damage. Especially under the combined action of various factors such as air pressure changes, load, driving speed, and road conditions, slippage or dislocation is likely to occur at the contact part between the tire bead and the rim during the rolling process of the tire. Such adverse phenomena not only cause faults such as tire bead cracking and abnormal bead wear, but also reduce the overall performance of the tire, increase the risk of tire blowout, and thus seriously affect vehicle safety and handling stability.

[0003] Korean Patent KR 10-2021-0004136A discloses a vehicle wheel with shock absorption and bead damage monitoring functions. Pressure sensors are embedded in the rim contact surface to monitor bead contact pressure and tire pressure. However, the pressure sensors cannot quantify the dynamic displacement changes of the bead caused by bead deformation. Therefore, the accuracy of the above-mentioned wheel in presenting the dynamic fitting state between the bead and the rim needs to be further improved. Summary of the Invention

[0004] In view of the deficiencies in the related art, the present invention provides a device and method for real-time monitoring of the contact state of a tire bead. Based on the interdigital capacitive MEMS acoustic emission sensor, the real-time dynamic displacement curve of the contact area between the bead and the rim can be monitored in real time under static inflation, static load, and rolling conditions of the tire, and whether abnormal sliding or dislocation occurs at the bead can be monitored. The present invention solves the problem that traditional monitoring methods cannot quantify the dynamic displacement changes of the bead caused by bead deformation.

[0005] The present invention provides a device for real-time monitoring of the contact state of a tire bead, including: a sensor module, with one or more arranged on the rim. The sensor module includes: a plurality of interdigital capacitive MEMS acoustic emission sensors arranged along the edge of any radial cross-section of the rim close to the bead side, and the monitoring direction is perpendicular to the rim surface.

[0006] In some embodiments, the sensor module further includes: a plurality of piezoelectric film sensors arranged along the edge of the radial cross-section of the rim close to the bead side; the piezoelectric film sensors are located between the interdigital capacitive MEMS acoustic emission sensors and the rim.

[0007] In some of these embodiments, the sensor module further includes: an electrical signal shielding layer located between the interdigital capacitive MEMS acoustic emission sensor and the piezoelectric film sensor.

[0008] In some of these embodiments, both the piezoelectric film sensor and the interdigital capacitive MEMS acoustic emission sensor are electrically connected to other structures through elastic contacts.

[0009] In some of these embodiments, the piezoelectric film sensors and the interdigital capacitive MEMS acoustic emission sensors are in one-to-one correspondence, and the corresponding piezoelectric film sensors and interdigital capacitive MEMS acoustic emission sensors are aligned vertically.

[0010] In some of these embodiments, the device further includes: a transmission module disposed on the rim for establishing a signal connection between the sensor module and other devices. The transmission module uses wireless communication means for signal transmission.

[0011] In some of these embodiments, the device further includes: a power supply module disposed outside the rim and connected to the sensor module and the transmission module.

[0012] A charging port is disposed on the rim and connected to the power supply module.

[0013] In some of these embodiments, the power supply module includes: a housing fixedly connected to the rim.

[0014] A capacitor is located inside the housing and connected to the sensor module, the transmission module, and the charging port.

[0015] A piezoelectric device is located inside the housing and connected to the capacitor for converting the vibration, deformation, and centrifugal force of the wheel into electrical energy.

[0016] In some of these embodiments, the power supply module further includes a flexible circuit board having a voltage stabilizing circuit and an overvoltage protection circuit. The piezoelectric device is connected to the capacitor through the flexible circuit board.

[0017] The present invention also provides a method for real-time monitoring of the contact state of the tire bead. The device for real-time monitoring of the contact state of the tire bead described above is used; the interdigital capacitive MEMS acoustic emission sensor monitors the distance between the tire bead and the rim in real time, draws the bead contour based on the monitoring results of all interdigital capacitive MEMS acoustic emission sensors, overlaps the bead contours at different time periods, and analyzes the dynamic displacement change of the bead relative to the rim.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. The present invention breaks through the bottleneck of traditional monitoring methods. Based on the interdigital capacitive MEMS acoustic emission sensor, it can real-time monitor the real-time dynamic displacement curve at the fitting position between the bead and the rim of the tire under static inflation, static load and rolling conditions, and monitor whether abnormal sliding or dislocation occurs at the bead. It provides key information for optimizing the bead curve, helps to design a bead shape that better conforms to the mechanical distribution, reduces the risk of fatigue damage, improves the durability and reliability of the tire bead part, extends the service life of the tire, and ensures the safety of the vehicle.

[0020] 2. Based on the piezoelectric thin film sensor and the interdigital capacitive MEMS acoustic emission sensor, the present invention can real-time monitor the real-time dynamic displacement curve and the real-time contact pressure distribution at the fitting position between the bead and the rim of the tire under static inflation, static load and rolling conditions, which helps to accurately monitor whether abnormal sliding or dislocation occurs at the bead. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0022] Figure 1 is a schematic structural diagram of the present invention installed on a wheel.

[0023] Figure 2 is Figure 1 an enlarged schematic view of area A in

[0024] Figure 3 is a schematic structural diagram showing the power supply module in the present invention;

[0025] Figure 4 is Figure 3 an enlarged schematic view of area B in

[0026] Figure 5 is a combined schematic diagram of the bead profile curve and the pressure distribution detected by the sensor module of the present invention.

[0027] In the figure: 1. Sensor module; 11. Flexible substrate; 12. Piezoelectric thin film sensor; 13. Electrical signal shielding layer; 2. Shielded twisted pair; 3. Power supply module; 31. Housing; 32. Capacitor; 33. Piezoelectric device; 34. Locking structure; 341. Chamfer; 35. Flexible circuit board; 4. Charging port; 5. Bead; 6. Rim; 61. Second installation groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0030] The terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include one or more of such features.

[0031] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0032] As Figures 1-4 shown, in an embodiment of a device for real-time monitoring of the contact state of a tire bead in the present invention, the device for real-time monitoring of the contact state of a tire bead 5 at least includes:

[0033] The present invention provides a device for real-time monitoring of the contact state of a tire bead 5, including: a sensor module 1, with one or more provided on a rim 6. Each sensor module 1 monitors the contact state between a bead 5 and the rim 6 in real time.

[0034] The sensor module 1 includes a plurality of interdigital capacitive MEMS acoustic emission sensors located on the same plane. All the interdigital capacitive MEMS acoustic emission sensors in a single sensor module 1 are distributed along the edge of the bead 5 on the radial section of the rim 6, and the monitoring range of a single sensor module 1 covers the full width of the bead 5 in the tire radial direction. The monitoring direction of a single interdigital capacitive MEMS acoustic emission sensor is the normal direction of the area plane of the rim 6 where it is located. The above-mentioned interdigital capacitive MEMS acoustic emission sensor is a prior art, and its structure is described in Chinese Patent CN117214304A, which will not be elaborated here.

[0035] Taking a single sensor module 1 as an example, during the rotation of the wheel, the interdigital capacitive MEMS acoustic emission sensor monitors the distance between the tire bead 5 and the rim 6 in real time. Based on the monitoring results of all the interdigital capacitive MEMS acoustic emission sensors, the bead 5 contour can be drawn. By overlapping the bead 5 contours at different time periods, the dynamic displacement change of the bead 5 relative to the rim 6 can be analyzed. Compared with the conventional method of only analyzing the dynamic fitting state between the bead 5 and the rim 6 based on a pressure sensor, the above-mentioned sensor module 1 can quantify the displacement change between the bead 5 and the rim 6 in real time, and the above-mentioned sensor module 1 has a higher presentation accuracy for the dynamic fitting state between the bead 5 and the rim 6.

[0036] Furthermore, in a single sensor module, the distance between adjacent interdigital capacitive MEMS acoustic emission sensors on the edge of the rim radial section close to the bead is the same. Based on the distances between the bead 5 and the rim 6 collected by all the interdigital capacitive MEMS acoustic emission sensors in a single sensor module 1, a bead contour curve of the current wheel radial section is generated through cubic spline interpolation.

[0037] Furthermore, all the interdigital capacitive MEMS acoustic emission sensors of a single sensor module 1 are installed on the same flexible substrate 11, and the flexible substrate 11 is fixed on the rim 6. All the interdigital capacitive MEMS acoustic emission sensors can be first integrated into one body through the flexible substrate 11, and then installed on the rim 6 through the flexible substrate 11 to improve the installation efficiency and installation position accuracy of the interdigital capacitive MEMS acoustic emission sensors. In addition, the flexible substrate 11 can better fit the shape of the rim 6, which helps to improve the monitoring accuracy. The interdigital capacitive MEMS acoustic emission sensors are located inside the flexible substrate 11, Figure 2 The interdigital capacitive MEMS acoustic emission sensors are not shown.

[0038] Preferably, the elastic modulus of the flexible substrate 11 is 10 - 100 MPa, and the matching error between the curvature of the flexible substrate 11 on the rim 6 and the curvature of the rim 6 is less than ±0.5 mm.

[0039] Further, the flexible substrate 11 is made of an insulating material to reduce the mutual interference between different interdigital capacitive MEMS acoustic emission sensors. The flexible substrate 11 is preferably a flexible polyimide film. Conductive wires are arranged inside the flexible substrate 11, and all the interdigital capacitive MEMS acoustic emission sensors are electrically connected to other structures through different conductive wires.

[0040] Further, the conductive wires are shielded twisted pairs 2 to reduce common-mode interference.

[0041] In some embodiments, two sets of sensor modules 1 are provided, with at least one sensor module 1 in each set. The two sets of sensor modules 1 respectively monitor the contact states between two sub-ports 5 and the rim 6.

[0042] Further, the two sets of sensor modules 1 are symmetrically arranged on the rim 6.

[0043] In some embodiments, multiple sensor modules 1 are provided. All the sensor modules 1 monitor the contact state between the same sub-port 5 and the rim 6, and all the sensor modules 1 are distributed around the axis of the rim 6.

[0044] In some embodiments, the sensor module 1 further includes: a plurality of piezoelectric film sensors 12 arranged along the edge on the side close to the sub-port 5 in the radial cross-section of the rim 6. The piezoelectric film sensors 12 are common products on the market, and their structures and principles will not be elaborated here.

[0045] Taking a single sensor module 1 as an example, during the rotation of the wheel, the piezoelectric film sensors 12 continuously monitor the contact pressure between the sub-port 5 and the rim 6. Based on the monitoring results of all the piezoelectric film sensors 12, the pressure distribution of the contact part between the rim 6 and the sub-port 5 can be plotted. By combining and analyzing the pressure distribution at different times, the dynamic change of the contact pressure between the rim 6 and the sub-port 5 can be obtained. By combining and analyzing the monitoring results of the piezoelectric film sensors 12 and the interdigital capacitive MEMS acoustic emission sensors, the presentation accuracy of the dynamic fitting state between the sub-port 5 and the rim 6 can be further improved.

[0046] Further, all the piezoelectric film sensors 12 are electrically connected to other structures through different conductive wires. The conductive wires are shielded twisted pairs 2 to reduce common-mode interference.

[0047] Further, the piezoelectric film sensors 12 are located between the interdigital capacitive MEMS acoustic emission sensors and the rim 6 to reduce the occupied area of the sensor module 1 on the rim 6 and reduce the interference of the sensor module 1 on the connection between the tire and the rim 6.

[0048] Further, the thickness of the piezoelectric film sensors 12 is preferably 0.1 mm to better fit the shape of the rim 6 and improve the monitoring accuracy.

[0049] In some of these embodiments, the piezoelectric thin film sensors 12 and the interdigital capacitive MEMS acoustic emission sensors correspond one-to-one. The corresponding piezoelectric thin film sensors 12 and interdigital capacitive MEMS acoustic emission sensors are aligned vertically to establish a one-to-one mapping relationship and improve the monitoring accuracy.

[0050] Furthermore, it is preferable that the included angle between the normal direction of each piezoelectric thin film sensor 12 and the normal direction of its corresponding interdigital capacitive MEMS acoustic emission sensor is less than or equal to 1°. It is also preferable that the spatial coordinate deviation between each piezoelectric thin film sensor 12 and its corresponding interdigital capacitive MEMS acoustic emission sensor is less than or equal to 0.1 mm, so as to further improve the alignment accuracy between the piezoelectric thin film sensors 12 and the interdigital capacitive MEMS acoustic emission sensors.

[0051] In some of these embodiments, the sensor module 1 further includes: an electrical signal shielding layer 13, which is located between the interdigital capacitive MEMS acoustic emission sensor and the piezoelectric thin film sensors 12.

[0052] Furthermore, the electrical signal shielding layer 13 is a flexible structure to better conform to the shape of the rim 6 and improve the monitoring accuracy of the sensor module 1.

[0053] Furthermore, the electrical signal shielding layer 13 is preferably a copper foil. The electrical signal shielding layer 13 is grounded to eliminate electromagnetic interference caused by the external environment to the sensor module 1. The grounding impedance of the electrical signal shielding layer 13 is less than 1 Ω. It is preferable that the copper foil thickness of the electrical signal shielding layer 13 is 0.05 mm.

[0054] Furthermore, the flexible substrate 11 is fixed on the side of the electrical signal shielding layer 13 away from the rim 6.

[0055] In some of these embodiments, the device further includes: a transmission module, which is arranged on the rim 6 and is used to establish a signal connection between the sensor module 1 and other devices. The transmission module uses wireless communication means for signal transmission. The transmission module Figure 1 is not shown.

[0056] Furthermore, the device further includes a preprocessing module. The sensor module 1 is signal-connected to the transmission module through the preprocessing module. The preprocessing module is used to perform filtering processing and compression processing on the data collected by the sensor module 1 to improve the wireless transmission efficiency of the transmission module. The preprocessing module is fixed on the rim. The preprocessing module is not shown in the figure.

[0057] In some of these embodiments, the device further includes: a power supply module 3, which is arranged outside the rim 6 and is connected to the sensor module 1 and the transmission module.

[0058] A charging port 4, which is arranged on the rim 6 and is connected to the power supply module 3.

[0059] Further, the charging port 4 is provided with an openable and closable flap to prevent foreign objects from hitting the charging port 4 during wheel travel.

[0060] Further, a sealing structure is provided between the charging port 4 and the rim 6 to achieve the effects of waterproofing and dustproofing, and to protect the sensor module 1, the power supply module 3, and the transmission module. The sealing structure diagram is not shown.

[0061] In some embodiments, the power supply module 3 includes: a housing 31 fixedly connected to the rim 6.

[0062] A capacitor 32 located inside the housing 31, connected to the sensor module 1, the transmission module, and the charging port 4. The capacitor 32 is used to supply power to the sensor module 1 and the transmission module, and the capacitor 32 receives power from an external power source through the charging port 4.

[0063] A piezoelectric device 33 located inside the housing 31, connected to the capacitor 32, and used to convert the vibration, deformation, and centrifugal force of the wheel into electrical energy. The piezoelectric device 33 includes, but is not limited to, piezoelectric films and piezoelectric ceramics.

[0064] The piezoelectric device 33 has a conventional structure and will not be described in detail here. When the wheel rotates, the piezoelectric device 33 converts the vibration, deformation, and centrifugal force of the wheel into electrical energy, and the electrical energy converted by the piezoelectric device 33 is stored in the capacitor 32. When the wheel is parked for a long time, it is easy for the capacitor 32 to self-discharge. At this time, the capacitor 32 can be charged through the charging port 4 to ensure the normal operation of the piezoelectric film sensor 12 and the interdigital capacitive MEMS acoustic emission sensor in the sensor module 1.

[0065] Further, the capacitor 32 is a supercapacitor 32 made of graphene and MXene. The supercapacitor 32 is an existing product, and its structure and principle will not be described in detail here.

[0066] Preferably, the rated voltage of the supercapacitor 32 is 3.6V, and the capacitance of the supercapacitor 32 is 10F.

[0067] Further, the housing 31 is made of a plastic structure and has a certain elasticity, so as to absorb the thermal expansion and vibration deformation between the rim 6 and the power supply module 3 through the elastic deformation of the housing 31, and maintain the structural stability of the housing 31. Preferably, the housing 31 is a glass fiber reinforced nylon housing.

[0068] In some embodiments, the housing 31 is provided with an opening. The power supply module 3 further includes a locking structure 34 detachably connected to the opening of the housing 31 for disassembling and maintaining the electrical structure inside the housing 31.

[0069] Furthermore, the opening is located on the side of the housing 31 away from the rim 6. The locking structure 34 is in annular snap-fit with the inner side wall of the opening, evenly dispersing the force exerted by the locking structure 34 on the housing 31 to each side wall of the housing 31, avoiding local stress concentration. When the wheel rotates at high speed, the centrifugal force can increase the connection strength between the locking structure 34 and the housing 31.

[0070] Furthermore, the locking structure 34 is a thin-walled structure made of spring steel.

[0071] Furthermore, the edge of the locking structure 34 on the side away from the rim 6 is chamfered at an angle 341 to facilitate snap-fitting into the inner side of the opening.

[0072] Furthermore, the angle between the inclined plane of the chamfer 341 and the horizontal plane is 10 - 15°, reducing the possibility of the locking structure 34 detaching from the housing 31 under the action of the centrifugal force of the wheel.

[0073] Furthermore, the magnitude of the locking force between the locking structure 34 and the housing 31 is determined by the safety factor of the rim. When the rim safety factor is 1.3, it is preferable that the locking force between the locking structure 34 and the housing 31 is 15 N.

[0074] In some embodiments, the power supply module 3 further includes a flexible circuit board 35, which has a voltage stabilizing circuit and an overvoltage protection circuit. The piezoelectric device 33 is connected to the capacitor 32 through the flexible circuit board 35.

[0075] Furthermore, the piezoelectric device 33 has an elastic shock-absorbing layer to attenuate high-frequency vibrations and protect the piezoelectric device 33.

[0076] In some embodiments, the piezoelectric device 33 is a piezoelectric film, which is located on the side of the capacitor 32 away from the rim 6, and the flexible circuit board 35 is located between the piezoelectric film and the capacitor 32. The flexible circuit board 35 is a highly reliable and excellent flexible printed circuit board made of polyimide or polyester film as the substrate.

[0077] Furthermore, it is preferable that the thickness of the piezoelectric film is 2 - 3 mm, and the flexible circuit board 35 is 0.3 mm.

[0078] Furthermore, the piezoelectric film is composed of a flexible piezoelectric layer and an elastic shock-absorbing layer. The elastic shock-absorbing layer can attenuate high-frequency vibrations and protect the flexible piezoelectric layer. The flexible piezoelectric layer is preferably a flexible polyvinylidene fluoride layer, and the elastic shock-absorbing layer is preferably an elastic silicone layer.

[0079] In some embodiments, a first installation groove for installing the sensor module 1 is provided on the rim 6 to further reduce the interference of the sensor module 1 on the connection between the tire and the rim 6. The first installation groove is not shown in the figure.

[0080] Further, before the rim 6 is connected to other structures, its surface needs to be electrolytically polished first, and then an annular reinforcing rib is formed by laser cladding technology to improve the structural strength of the rim 6 and reduce the influence of opening the first installation groove on the structural strength of the rim 6.

[0081] Further, the rim 6 has a silicon nitride protective layer to improve the structural strength of the rim 6 and reduce the influence of opening the first installation groove on the structural strength of the rim 6. The silicon nitride protective layer is not shown in the figure.

[0082] Further, a cured silicone sealant is also provided in the first installation groove. The cured silicone sealant is used to encapsulate the sensor module 1 in the first installation groove to protect the sensor module 1. After the sensor module 1 is placed in the first installation groove, a liquid silicone sealant material is injected into the first installation groove. The liquid silicone sealant material covers the sensor module 1, and then the liquid silicone sealant material is subjected to photocuring treatment to convert the liquid silicone sealant material into a cured silicone sealant. The cured silicone sealant is not shown in the figure.

[0083] Further, the photocuring treatment uses a 365 nm wavelength ultraviolet light source, with an irradiation intensity of 80 mW / cm2 and an irradiation time of 30 seconds.

[0084] In some embodiments, both the piezoelectric film sensor 12 and the interdigital capacitive MEMS acoustic emission sensor are electrically connected to other structures through elastic contact members. The elastic contact members are small in volume and have high electrical connection reliability, and are not prone to electrical connection disconnection problems in a vibration environment. The other structures referred to here include, but are not limited to, the power supply module 3 and the transmission module. The elastic contact members are not shown in the figure.

[0085] Further, the elastic contact member includes a spring pin and a copper sheet, and the spring pin and the copper sheet are in elastic contact. Each piezoelectric film sensor 12 corresponds to an elastic contact member, and each interdigital capacitive MEMS acoustic emission sensor corresponds to an elastic contact member. The piezoelectric film sensor 12 is connected to the corresponding spring pin, and the copper sheet corresponding to the spring pin is installed on the electrical connection object of the piezoelectric film sensor 12. The interdigital capacitive MEMS acoustic emission sensor is connected to the corresponding spring pin, and the copper sheet corresponding to the spring pin is installed on the electrical connection object of the interdigital capacitive MEMS acoustic emission sensor.

[0086] In some embodiments, a second installation groove 61 for installing the power supply module 3 is provided on the rim 6 to reduce the interference of the power supply module 3 on the connection between the tire and the rim 6.

[0087] Further, in the radial direction of the wheel, the distance between the power supply module 3 and the tire bead is greater than or equal to 15 mm to prevent the deformation of the tire from interfering with the normal operation of the power supply module 3.

[0088] The present invention also provides a method for real-time monitoring of the contact state of the tire bead. In its embodiment, the method at least includes the following: using the device for real-time monitoring of the contact state of the tire bead; the interdigital capacitive MEMS acoustic emission sensor monitors the distance between the tire bead and the rim in real time, draws the bead contour based on the monitoring results of all interdigital capacitive MEMS acoustic emission sensors, overlaps the bead contours at different time periods, and analyzes the dynamic displacement change of the bead relative to the rim.

[0089] Furthermore, based on the monitoring results of all piezoelectric film sensors 12, the pressure distribution of the contact part between the rim 6 and the bead 5 is drawn, and the pressure distribution at different time periods is combined and analyzed to obtain the dynamic contact pressure change between the rim 6 and the bead 5. Combining the monitoring results of the piezoelectric film sensors 12 and the interdigital capacitive MEMS acoustic emission sensors can further improve the presentation accuracy of the dynamic fitting state of the bead 5 and the rim 6.

[0090] Furthermore, as Figure 5 shown, mapping the pressure value to a color can directly display the pressure distribution in the form of a gradient color on the bead contour curve obtained based on the detection results of the interdigital capacitive MEMS acoustic emission sensors, so that users can visually observe the pressure distribution on this curve and quickly identify abnormal areas. If the detection data of a certain piezoelectric film sensor 12 is missing, the detection results of two adjacent piezoelectric film sensors 12 are used for linear interpolation to complete it. The parallel processing of data acquisition and interface rendering is realized through a dual-thread architecture to ensure real-time performance, refresh the curve color every second, and display the change of the pressure distribution during tire rolling in real time. Figure 5 In [figure], the red dots represent the detection results of the interdigital capacitive MEMS acoustic emission sensors, and the color bars represent the detection results of the piezoelectric film sensors 12. The color bars represent the pressure values from large to small with a gradient color from red to blue.

[0091] In some of these embodiments, the wireless transmission of the transmission module employs multi-modal collaborative communication and has an adaptive anti-interference mechanism. The sensor data is processed through the physical layer protocol stack in a hierarchical manner. First, at the application layer, the signals of the interdigital capacitive MEMS acoustic emission sensor and the piezoelectric film sensor are encoded with spatio-temporal alignment. The data stream is segmented into multiple subcarriers using Orthogonal Frequency Division Multiplexing (OFDM), and combined with Frequency Hopping Spread Spectrum (FHSS) to dynamically switch 16 1-MHz sub-channels within the 2.4 GHz band to avoid co-channel interference. The transport layer adopts a hybrid error correction strategy, achieving an error correction capacity of 32 bytes per data packet through Reed-Solomon coding. At the same time, the physical layer enhances the anti-multipath fading characteristics with Differential Phase Shift Keying (DPSK) modulation. Data encryption uses the AES-128-CTR mode, and dynamic per-packet key updates are implemented at the MAC layer to ensure information security. The receiving end separates the multipath signals through MIMO beamforming technology, and uses the Minimum Mean Square Error (MMSE) algorithm to eliminate the Doppler frequency offset caused by tire rotation (maximum compensation ±5 kHz). Finally, the data stream after CRC check is reconstructed into the contact pressure field through cubic spline interpolation. Its essence is to establish a reliable transmission channel in the three-dimensional space of time-frequency-code through the joint phase-amplitude modulation of the electromagnetic wave carrier frequency, realizing the lossless mapping from the sensor signal to the visualization curve.

[0092] In some of these embodiments, the sampling rate of the interdigital capacitive MEMS acoustic emission sensor is 200 Hz, the time resolution is 5 ms, and the bandwidth is 1 - 100 Hz. The detection results of the interdigital capacitive MEMS acoustic emission sensor are processed by a 4th-order Butterworth low-pass filter in the preprocessing module and then transmitted to the transmission module. The sampling rate of the piezoelectric film sensor 12 is 2 kHz, the time resolution is 0.5 ms, and the bandwidth is 100 - 1000 Hz. The detection results of the piezoelectric film sensor 12 are processed by an adaptive band-pass filter in the preprocessing module and then transmitted to the transmission module.

[0093] Through the description of multiple embodiments of the device and method for real-time monitoring of the contact state of the tire bead 5 of the present invention, it can be seen that the embodiments of the device and method for real-time monitoring of the contact state of the tire bead 5 of the present invention have at least one or more of the following advantages:

[0094] 1. The present invention breaks through the bottleneck of traditional monitoring methods. Based on the interdigital capacitive MEMS acoustic emission sensor, it can real-time monitor the real-time dynamic displacement curve at the joint of the bead 5 and the rim 6 under static inflation, static load, and rolling conditions of the tire, and monitor whether abnormal sliding or dislocation occurs at the bead 5. It provides key information for optimizing the bead 5 curve, helps to design a bead 5 shape that better conforms to the mechanical distribution, reduces the risk of fatigue damage, improves the durability and reliability of the tire bead 5 part, extends the tire service life, and ensures the safety of the vehicle.

[0095] 2. Based on the piezoelectric thin film sensor 12 and the interdigital capacitive MEMS acoustic emission sensor, the present invention can monitor in real time the real-time dynamic displacement curve and the real-time contact pressure distribution at the joint between the bead 5 and the rim 6 under the conditions of static inflation, static load and rolling of the tire, which helps to monitor with high precision whether abnormal sliding or dislocation occurs at the bead 5.

[0096] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and the key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0097] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still modifications can be made to the specific implementation manners of the present invention or equivalent replacements can be made to some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A device capable of real-time monitoring of the contact state of the tire bead, characterized in that, Comprising: A sensor module, with one or more arranged on the rim; the sensor module includes: Interdigital capacitive MEMS acoustic emission sensors, with multiple arranged along the edge near the bead side of any radial cross-section of the rim, and the monitoring direction is perpendicular to the rim surface; A flexible substrate; all the interdigital capacitive MEMS acoustic emission sensors are mounted on the same flexible substrate, and the flexible substrate is fixed on the rim.

2. The device for real-time monitoring of the contact state of the tire bead according to claim 1, characterized in that, The sensor module further includes: piezoelectric film sensors, with multiple arranged along the edge near the bead side of the radial cross-section of the rim; the piezoelectric film sensors are located between the interdigital capacitive MEMS acoustic emission sensors and the rim.

3. The device for real-time monitoring of the contact state of the tire bead according to claim 2, characterized in that, The sensor module further includes: an electrical signal shielding layer, located between the interdigital capacitive MEMS acoustic emission sensors and the piezoelectric film sensors.

4. The device for real-time monitoring of the contact state of the tire bead according to claim 2, characterized in that, Both the piezoelectric film sensors and the interdigital capacitive MEMS acoustic emission sensors are electrically connected to other structures through elastic contact parts.

5. The device for real-time monitoring of the contact state of the tire bead according to claim 2, characterized in that, The piezoelectric film sensors and the interdigital capacitive MEMS acoustic emission sensors are in one-to-one correspondence, and the corresponding piezoelectric film sensors and interdigital capacitive MEMS acoustic emission sensors are aligned vertically.

6. A device for real-time monitoring of the contact state of the tire bead according to any one of claims 1-5, characterized in that, Further comprising: A transmission module, arranged on the rim, for establishing a signal connection between the sensor module and other devices; The transmission module uses wireless communication means for signal transmission.

7. The device for real-time monitoring of the contact state of the tire bead according to claim 6, characterized in that, Further comprising: A power supply module, arranged outside the rim, connected to the sensor module and the transmission module; A charging port, arranged on the rim, connected to the power supply module.

8. A device for real-time monitoring of the contact state of a tire bead, according to claim 7, characterized in that, The power supply module includes: a housing, fixedly connected to the rim; A capacitor, located inside the housing, connected to the sensor module, the transmission module, and the charging port; A piezoelectric device, located inside the housing, connected to the capacitor, and used for converting the vibration, deformation, and centrifugal force of the wheel into electrical energy.

9. The device for real-time monitoring of the contact state of the tire bead according to claim 8, characterized in that, The power supply module further includes a flexible circuit board, and the flexible circuit board has a voltage stabilizing circuit and an overvoltage protection circuit; the piezoelectric device is connected to the capacitor through the flexible circuit board.

10. A method for real-time monitoring of the contact state of the tire bead, characterized in that, Using the device according to any one of claims 1-9 that can monitor the contact state of the tire bead in real time; the interdigital capacitive MEMS acoustic emission sensors monitor the distance between the tire bead and the rim in real time, draw the bead contour based on the monitoring results of all the interdigital capacitive MEMS acoustic emission sensors, overlap the bead contours at different times, and analyze the dynamic displacement change of the bead relative to the rim.

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