A self-generating wireless truck wheel hub temperature monitoring system

Abstract

This invention discloses a self-generating wireless truck wheel hub temperature monitoring system, including a truck suspension vibration power generation device with a composite energy conversion coordination mechanism, and a matching wireless truck wheel hub temperature monitoring scheme. The device achieves self-powering for the temperature monitoring and wireless signal transmission system through an energy harvesting device installed on the truck suspension. The system mainly includes an antenna integrated with the truck suspension, a signal processing module, a self-generating module, and a temperature sensor. The self-generating module includes an electromagnetic power generation structure and a piezoelectric power generation structure. Combining electromagnetic induction, piezoelectric effect, triboelectric effect, and the multidirectional and nonlinear forces generated by the spring and arched beam structure, it broadens the energy harvesting bandwidth. The combination of the two power generation modules achieves broadband composite energy harvesting. The composite self-generating module powers the monitoring system, and the integrated signal processing circuit is responsible for power management and wireless transmission of temperature signals, improving the safety of truck operation.

Description

Technical Field

[0001] This invention relates to the field of truck safety monitoring technology, specifically a self-generating wireless truck wheel hub temperature monitoring system. Background Technology

[0002] In the field of highway freight transport, the driving safety of heavy-duty trucks is a major issue concerning public safety. Due to their large size and heavy loads, trucks, especially drum brakes, generate enormous amounts of heat due to continuous friction during long downhill stretches or frequent braking. If this heat cannot dissipate in time, the brake disc temperature will rise sharply, triggering a severe "heat fade" effect, leading to a significant reduction in braking performance or even complete brake failure. This can easily cause serious traffic accidents and pose a significant threat to the safety of drivers, passengers, and the public. Therefore, there is an urgent need in this field for an intelligent system capable of real-time, accurate, and reliable monitoring of truck brake temperature and timely early warning systems to prevent safety accidents caused by brake overheating at the source.

[0003] To address this, this invention employs a hybrid power generation technology to achieve efficient harvesting of vibration energy from truck suspension. Electrical energy is generated by a magnet-excited coil, driving the deformation of the piezoelectric cantilever beam and the relative movement of the triboelectric electrodes, thereby capturing and utilizing the vibration energy of the truck suspension during operation. Optimized structural design of the energy harvester allows for efficient use of limited space. The energy harvesting module converts vibration into electrical energy, powering the energy conversion circuit, temperature monitoring system, and wireless signal transmission, reducing the truck's wiring requirements. This invention provides an effective solution for meeting the needs of truck wheel hub temperature monitoring systems and improving driving safety. Summary of the Invention

[0004] This invention proposes a self-generating wireless truck wheel hub temperature monitoring system. It employs an electromagnetic-piezoelectric composite energy harvesting technology to efficiently convert the vibration energy of the truck suspension into electrical energy, which is then used in the temperature measurement and signal transmission systems. On one hand, the device enhances energy harvesting power through the composite energy harvesting technology; on the other hand, the generated electrical energy powers the truck brake disc temperature monitoring system, processing and wirelessly transmitting the brake disc temperature signal to the driver, thus improving driving safety.

[0005] This system utilizes a combined mechanism of electromagnetic induction, triboelectric effect, and piezoelectric effect to achieve the coordinated conversion of energy from multiple physical fields, thereby capturing and utilizing the vibration energy generated during truck operation. This device not only enables the wheel hub brake temperature monitoring system to be self-powered, reducing system wiring, but also processes and wirelessly transmits brake disc temperature signals, providing timely feedback to the driver and effectively improving driving safety. It possesses high practicality and widespread application value.

[0006] This invention is installed in the gaps of a vehicle's suspension and consists of an antenna, signal processing circuitry, a self-generating power module, and a temperature sensor. The energy harvesting module mainly comprises a three-layer structure, including an electromagnetic power generation structure and a piezoelectric power generation structure within the outer casing.

[0007] The composite integrated energy harvesting structure proposed in this invention has the following characteristics: 1. A three-layer energy harvesting structure is installed inside the top cover and outer shell. 2. The electromagnetic power generation structure consists of a square array of magnets moving under vibration, with a central spring amplifying the vibration. The array of magnets uses a Hellbeck array to enhance the magnetic induction effect, and four sets of coils with iron cores are arranged in a reasonable spatial configuration to generate electrical energy based on electromagnetic induction. 3. The piezoelectric power generation structure generates electrical energy based on the piezoelectric effect. Its main structure uses an arched cantilever beam, with the piezoelectric layer adhered to the surface of the base arched beam. Magnets and springs are used to provide nonlinear force. The base arched beams of the four sets of arched cantilever beams have different thicknesses to broaden the energy harvesting frequency band. 4. Two other energy harvesting devices are proposed to replace the cantilever beam energy harvester of the piezoelectric power generation structure: a windmill-shaped multi-directional piezoelectric power generation structure and a sliding triboelectric power generation mechanism. These provide a multi-directional energy harvesting scheme and a scheme for generating electrical energy through triboelectric effect, respectively. Specific technical solutions are as follows:

[0008] A self-generating wireless truck wheel hub temperature monitoring system includes a protective shell, an antenna, a signal processing module, a self-generating module, and a temperature sensor. The self-generating module is fixed inside the protective shell, the protective shell is fixed to the truck axle through mounting holes, the self-generating module is connected to the signal processing module, and the temperature sensor is installed on the surface of the brake disc.

[0009] The self-generating module includes an electromagnetic power generation structure and a piezoelectric power generation structure;

[0010] The signal processing module includes an energy conversion and storage circuit, a temperature monitoring circuit, and a signal transceiver module. The energy conversion and storage circuit converts and stores the energy generated by the self-generating module to power the entire system. The signal transceiver module includes two wireless transceiver controllers as transmitters and receivers, with the transmitters connected to antennas. The temperature detection circuit is connected to a temperature sensor to monitor the temperature and control the transmitters to send temperature information and warning signals to the receivers.

[0011] The electromagnetic power generation structure includes a central spring, an array of magnets, an excitation coil, and an iron core located inside the coil. The central spring is divided into two parts, with the middle part fixed to the array of magnets and the upper and lower ends fixed to the top and bottom of the protective shell. There are four coils, fixed on the side of the protective shell and evenly distributed around both sides of the array of magnets. The central spring and the array of magnets constitute the mover, and the four sets of parallel power generation coils and their internal iron cores constitute the stator.

[0012] The piezoelectric power generation structure is a double-layer structure in the system, located on both sides of the electromagnetic power generation structure, and contains a total of four sets of piezoelectric cantilever beams. The two piezoelectric cantilever beam structures on each side of the piezoelectric power generation structure are symmetrical.

[0013] A single piezoelectric cantilever beam structure consists of a spring, a base arched beam, a mass block, a piezoelectric layer, and an excitation magnet. The base arched beam is a semi-circular arch structure, with both ends extending outwards along the diameter direction. One end of the base arched beam and the excitation magnet are fixed to both sides of the protective shell, respectively. The piezoelectric layer is bonded to the outer surface of the base arched beam, with the convex side of the arch being the outer side. The spring is fixed between the inner surface of the other end of the base arched beam and the protective shell. The mass block is fixed to the outer surface of the piezoelectric layer opposite to the spring's fixed position.

[0014] The piezoelectric power generation structure is a double-layer structure in the system, located on both sides of the electromagnetic power generation structure. The piezoelectric power generation structure on one side is a windmill-shaped multi-directional piezoelectric energy harvesting device, including leaf springs, piezoelectric plates, a windmill-shaped torsion beam, a drive spring, and a mass block. The four leaf springs are respectively fixed to the ends of the four beams of the windmill-shaped torsion beam, and the other ends of the four leaf springs are respectively connected to the top, bottom, left, and right sides of the outer shell. The piezoelectric plates are installed on the surface of the four beams of the windmill-shaped torsion beam, and the two ends of the drive spring are respectively fixed to the center of the windmill-shaped torsion beam and the mass block.

[0015] The piezoelectric power generation structure is replaced by a triboelectric energy harvesting device, which has a double-layer structure in the system, located on both sides of the electromagnetic power generation structure. The triboelectric energy harvesting device on one side includes a spring shaft, a triboelectric array magnet, an electrode layer, a mounting plate, wires, and a triboelectric layer. The center of the spring shaft is fixed to the groove of the triboelectric array magnet, and the upper and lower ends are fixed to the reserved grooves on the upper and lower parts of the protective shell. Flexible substrates with equal spacing are fixed on the non-driving coil surfaces on the left and right sides of the triboelectric array magnet, and the electrode layer is pasted on the surface of the flexible substrate. The triboelectric layer is composed of strips of polytetrafluoroethylene film with equal spacing, which is installed on the surface of the mounting plate. The strips of polytetrafluoroethylene film are connected by wires, and their width and spacing match the aluminum electrode layer.

[0016] The energy conversion and storage circuit is as follows: the positive and negative poles of the four coils in the electromagnetic power generation structure are respectively connected to the rectifier bridge circuit, and then after being processed by the first energy conversion module, they are sent to the energy storage module. The positive and negative poles of the four piezoelectric layers of the piezoelectric power generation structure are respectively connected to the rectifier bridge circuit. After the positive poles of the rectifier bridge are connected in parallel, they are connected to the second energy conversion module. After processing, they are connected in parallel with the first energy conversion module and input to the energy storage module together.

[0017] The energy conversion and storage circuit is as follows: The positive and negative poles of the four coils in the electromagnetic power generation structure are respectively connected to the rectifier bridge circuit, and then after being processed by the first energy conversion module, they are sent to the energy storage module. The positive and negative poles of the two triboelectric energy harvesting devices are respectively connected to the rectifier bridge circuit. After the positive poles of the rectifier bridge are connected in parallel, they are connected to the third energy conversion module. After processing, they are connected in parallel with the first energy conversion module and input to the energy storage module together.

[0018] This invention differs from traditional truck brake temperature monitoring systems. This self-powered truck wheel hub temperature monitoring system has the following features: it integrates a self-generating module to achieve overall self-powering of the monitoring system; it integrates the signal processing circuit with energy conversion and storage circuits, temperature signal processing circuits, and wireless transceiver modules to achieve wireless transmission of temperature signals, greatly simplifying truck wiring; and it can eliminate dependence on traditional batteries by collecting vibration energy.

[0019] This invention proposes a self-generating wireless truck wheel hub temperature monitoring system, which has broader application prospects compared to traditional truck brake temperature measurement and control methods. The truck wheel hub temperature monitoring system proposed in this invention, integrating a composite energy harvesting device and a wireless signal processing transmission system, has the following advantages over traditional truck brake temperature measurement and control systems:

[0020] 1. This invention has the ability to generate its own power, which can provide a stable power supply for temperature monitoring systems and wireless signal transmission systems, avoiding dependence on external power sources or batteries, effectively solving the problems of complex wiring and inconvenient maintenance in traditional monitoring systems, and reducing material waste caused by multiple maintenance.

[0021] 2. By introducing multiple energy harvesting mechanisms, the vibration energy of the truck suspension during driving is fully recovered, achieving efficient energy conversion and utilization, and significantly improving energy recovery efficiency.

[0022] 3. The integration of the energy harvesting module with the wireless signal processing and transmission system improves space utilization and makes the overall structure of the device compact, aesthetically pleasing, and easy to install and maintain.

[0023] In summary, this invention provides an innovative solution for truck wheel hub temperature monitoring systems, with broad application prospects and significant practical implications. Attached Figure Description

[0024] The functionality of these examples will become apparent and easier to understand from the following description and accompanying figures.

[0025] Figure 1 A schematic diagram showing the installation location of a self-generated wireless truck wheel hub temperature monitoring system.

[0026] Figure 2 This is a diagram showing the external appearance and internal structure of the self-generating module.

[0027] Figure 3 This is a cross-sectional view of the electromagnetic power generation structure layer.

[0028] Figure 4 This is a layout diagram of the electromagnetic power generation structure and a detailed layout of the array magnets.

[0029] Figure 5 This is a layout diagram and cross-sectional view of a piezoelectric power generation structure.

[0030] Figure 6 This is a cross-sectional view and layout diagram of a windmill-shaped multidirectional piezoelectric power generation structure.

[0031] Figure 7 This is a layout diagram of a sliding triboelectric power generation mechanism.

[0032] Figure 8 This is a schematic diagram of a sliding triboelectric power generation mechanism.

[0033] Figure 9 This is a schematic diagram of the energy harvesting circuit for electromagnetic and piezoelectric power generation systems.

[0034] Figure 10 This is a schematic diagram of the energy harvesting circuit for an electromagnetic and triboelectric power generation system.

[0035] Figure 11 Layout for temperature measurement and wireless signal transceiver systems.

[0036] Figure 12 This is a flowchart of a self-sourced integrated composite energy harvesting device.

[0037] Figure 13 This is a flowchart for temperature monitoring and wireless signal transmission and reception alarm feedback.

[0038] These accompanying drawings are intended to illustrate various aspects of the invention and do not limit the scope of dimensions, materials, configurations, or proportions, unless otherwise specified in the claims. Detailed Implementation

[0039] The examples will now be described in detail with reference to the accompanying drawings. The dimensions or thickness of the examples have been exaggerated for clarity.

[0040] Figure 1This is a schematic diagram of the installation location of a self-generating wireless truck wheel hub temperature monitoring system. The system includes a protective housing, antenna 10, signal processing module 20, self-generating module 30, and temperature sensor 60. The self-generating module 30 is fixed inside the protective housing, which is then fixed to the truck's axle 50 via mounting holes 40, without affecting the normal operation of other components on the axle, such as springs and shock absorbers. The self-generating module 30 is connected to the signal processing module 20, which integrates energy harvesting and conversion circuitry as well as wireless signal transmission and reception functions. Module integration is achieved through PCB manufacturing. Mounting the signal processing module 20 and antenna 10 on the side of the protective housing closer to the temperature sensor helps reduce the arrangement of signal transmission wires. The temperature sensor 60 is mounted on the surface of the brake disc 70. Figure 1 The right side shows an installation view of the temperature sensor 60. This embodiment uses a PT1000 temperature sensor, which converts temperature changes into resistance changes. By monitoring this resistance value, the temperature of the brake disc 70 can be determined. Drum brakes are low-cost and provide high braking force, commonly used in large trucks. However, their heat dissipation is poor, and excessively high temperatures can lead to a decline in braking performance, making them unsuitable for frequent braking. Therefore, monitoring brake temperature is crucial. Here, brake disc 70 refers to the housing of a drum brake, but it can also refer to the friction pad mounting bracket of a disc brake. Installing the temperature sensor 60 on the surface of the brake disc 70 enables real-time temperature monitoring. By statistically analyzing the temperature of each wheel, an alarm can be issued to the driver when any wheel's brake disc experiences an abnormal temperature.

[0041] Figure 2 This is an external view of the protective casing and a schematic diagram of the internal self-generating module structure. The protective casing includes a top cover 80 and an outer shell 90. The top cover 80 is equipped with a lifting ring to facilitate the removal of the top layer structure; the outer shell 90 is designed with mounting holes 40 for connection to the axle. Figure 2 The right side shows the internal distribution of the self-generating module structure, as indicated by the arrows in the figure. It employs a three-layer structure, including a middle electromagnetic power generation structure 01 and two piezoelectric power generation structures 02 on either side. Each component is fixed to its corresponding mounting port inside the protective shell, ensuring stable connection. A spacer layer is provided between the three layers to reduce interference from the magnets in the electromagnetic power generation structure 01 to the piezoelectric power generation structure 02. This mechanism combines electromagnetic and piezoelectric power generation effects, achieving efficient recovery of vibration energy.

[0042] Figure 3 This is a cross-sectional view of layer 01 of the electromagnetic power generation structure. The electromagnetic power generation structure 01 includes a central spring 11, an array of magnets 12, excitation coils 13, and an iron core 14 located inside the coils 13. It is a power generation structure based on electromagnetic induction. The central spring 11 is divided into two parts, with the middle part fixed to a groove in the array of magnets 12, and the upper and lower ends fixed to reserved grooves in the upper cover 80 and outer shell 90 of the protective shell, providing support. There are four coils 13, fixed to the side of the protective shell, evenly distributed around both sides of the array of magnets 12, to... Figure 3 The cross-sectional views are located at the upper left, lower left, upper right, and lower right of the array magnet 12, respectively. Figure 2 The right-hand front view shows the positions directly above, below, above, and below the array magnet 12. Adding an iron core 14 inside each coil 13 significantly enhances the magnetic field strength. The central spring 11 and the array magnet 12 constitute the mover, while the four parallel-connected generating coils 13 and their internal iron cores 14 constitute the stator. The relative motion between the mover and stator causes a change in magnetic flux within the coil 13, generating electrical energy according to the law of electromagnetic induction. The significant increase in magnetic flux density within the iron core increases the coil inductance, thereby increasing the power generation.

[0043] Figure 4 This diagram shows the layout of the electromagnetic power generation structure 01 and the detailed layout of the array magnets 12. The left side shows the layout of the electromagnetic power generation structure 01, and the right side shows the detailed layout of the array magnets 12. The arrows in the diagram indicate the polarity arrangement of the magnets in the array, from bottom to top: top, left, bottom, right, bottom. This Hellbeck array, through a special arrangement of magnet units, enhances the magnetic field gradient in a single direction, aiming to achieve a stronger electromagnetic induction output with fewer magnets. Its square structure also improves space utilization, enhancing the electromagnetic induction effect on the coils 13 located on both sides.

[0044] Figure 5This is a layout diagram and cross-sectional view of the single-sided piezoelectric power generation structure 02. The piezoelectric power generation structure 02 is a double-layer structure located on both sides of the electromagnetic power generation structure, comprising four sets of piezoelectric cantilever beams. Each piezoelectric cantilever beam structure consists of a spring 21, a base arch beam 22, a mass block 23, a piezoelectric layer 24, and an excitation magnet 25. The two piezoelectric cantilever beam structures of the single-sided piezoelectric power generation structure 02 are symmetrical vertically. One end of the base arch beam and the excitation magnet 25 are fixed in pre-reserved slots on both sides of the protective shell. The base arch beam 22 is a semi-circular arch structure, with both ends of the arch extending outwards along the diameter direction. The piezoelectric layer 24 is bonded to the outer surface of the base arch beam 22 with epoxy resin adhesive, with the convex side of the arch being the outer side. The spring 21 is placed vertically and fixed between the inner surface of the other end of the base arch beam 22 and the protective shell. The mass block 23 is fixed to the outer surface of the piezoelectric layer opposite to the spring 21. The specific features of this structure are as follows: The arched cantilever piezoelectric structure, with its advantages of geometric nonlinearity, strain enhancement, multi-directional response, and structural adaptability, significantly improves the efficiency and practicality of energy harvesting, effectively collecting wide-frequency, multi-directional, low-amplitude environmental vibrations. The introduced spring 21 and excitation magnet 25 construct nonlinear forces for the power generation system, forming a bistable or tristable system, giving the system multiple stable equilibrium positions. This nonlinear characteristic allows the cantilever beam to undergo large-amplitude jumps under low-frequency excitation, thereby generating high voltage output under low-frequency conditions. The base arched beams 22 of the four sets of piezoelectric cantilever beams have different thicknesses. The thickness of the cantilever beam directly determines its stiffness, and different stiffnesses correspond to different resonant frequencies. Therefore, when beams of different thicknesses are combined into an array, the system possesses multiple resonant frequencies. When the environmental vibration frequency varies within a certain range, one or more beams will always have a resonant frequency close to it, thus being excited to resonate and generating considerable electrical energy output.

[0045] In the double-layer structure position of piezoelectric power generation structure 02, in addition to the piezoelectric cantilever beam scheme, a windmill-shaped multi-directional piezoelectric energy harvesting device can also be used to broaden the frequency range of energy harvesting and improve the power output of electrical energy. Figure 6A windmill-shaped multidirectional piezoelectric energy harvesting structure is demonstrated, comprising four leaf springs 31, piezoelectric plates 32, a windmill-shaped torsion beam 33, a drive spring 34, and a mass block 35. The four leaf springs 31 are fixed to the ends of the four beams of the windmill-shaped torsion beam 33, and the other ends of the four leaf springs 31 are connected to the top, bottom, left, and right sides of the outer shell, respectively. The piezoelectric plates 32 are mounted on the surfaces of the four beams of the windmill-shaped torsion beam 33. The two ends of the drive spring 34 are fixed to the center of the windmill-shaped torsion beam and the mass block, respectively. The structure operates as follows: when vibration occurs, the mass block 35 drives the drive spring 34 to bounce. The drive spring 34 is fixed to the center of the torsion beam 33; when the torsion beam 33 twists or vibrates, it bounces accordingly, thereby driving the piezoelectric plates 32 mounted on it to generate electricity. The leaf springs 31 and drive spring 34 in this structure can introduce nonlinear forces to broaden the frequency band, while the windmill-shaped torsion beam 33 endows the structure with multidirectional energy harvesting capabilities.

[0046] The double-layer structure of piezoelectric power generation structure 02 can also be replaced with a triboelectric energy harvesting device to improve power generation efficiency. Figure 7 This is a layout diagram of a sliding triboelectric power generation mechanism. The device includes a spring shaft, a friction array magnet 16, an electrode layer 41, a mounting plate 42, wires 43, and a friction layer 44. The center of the spring shaft is fixed to a groove in the friction array magnet 16, and its upper and lower ends are fixed to reserved grooves on the upper and lower parts of the protective shell. Seven sets of equidistantly distributed flexible substrates are fixed to the non-driving coil surfaces on both sides of the friction array magnet 16, and the electrode layer 41 is adhered to the surface of the flexible substrates. The friction layer 44 is composed of equidistantly distributed strips of PTFE (polytetrafluoroethylene) film, mounted on the surface of the mounting plate 42. The strips of PTFE film are connected by wires 43, and their width and spacing match those of the aluminum electrode layer 41; specifically, the friction layer and the electrode layer have the same width and spacing. When the friction array magnet 16 slides along the spring axis, the aluminum electrode layer 41 and the friction layer 44 slide relative to each other, thus generating electricity. When one axial sliding reaches its limit, the contact surface of the electrode layer 41 can flip itself due to the flexible material, as described in the diagram. Figure 8 As shown.

[0047] Figure 8 This is a schematic diagram of a triboelectric power generation mechanism. (See attached diagram) Figure 8 In (a), the grid-like polytetrafluoroethylene (PTFE) film of the friction layer 44 overlaps with the curved strip-shaped electrode layer of the aluminum electrode layer 41. Due to the negative charge of PTFE and the positive charge of the aluminum electrode layer, when the two come into contact, negative charges accumulate on the PTFE surface, and an equal amount of positive charges accumulate on the aluminum electrode layer surface, and the system is in electrostatic equilibrium. See Figure 8 In (b), when the aluminum electrode layer 41 slides to the left and the friction layer 44 is relatively stationary, a potential difference is formed between adjacent flexible strip aluminum electrode layers, and the generated current is stored and then supplied to the load. See Figure 8 In (c), when the aluminum electrode layer 41 continues to slide and reaches the boundary of the friction layer 44, the array magnet 12 will drive the electrode layer to reciprocate. This is the moment when the aluminum electrode layer 41 has not bent in the ultimate state. See Figure 8 (d) to (f) represent the triboelectric sliding situation in opposite directions. The actual power generation details and... Figure 8 The process shown in (a) to (c) is consistent; repeating this process will yield a continuous electrical output.

[0048] The signal processing circuit 20 includes an energy conversion and storage circuit, a temperature monitoring circuit, and a signal transceiver module. One possible circuit structure for the energy conversion and storage circuit is as follows: Figure 9 As shown, energy is harvested through electromagnetic and piezoelectric power generation. The left side shows the electromagnetic power generation processing circuit, where a voltage source, inductor, and resistor connected in series represent the electromagnetic power generation model. The positive and negative terminals of the four coils in the electromagnetic power generation structure are connected to a rectifier bridge circuit to convert the AC power generated by the coils into DC power. The positive terminals of the rectifier bridge are connected in parallel and then connected to the input port of the first energy conversion module (using the BQ25570 chip in this embodiment), with the negative terminal grounded. After processing by the first energy conversion module, the energy is delivered to the energy storage module through the output port to power the temperature monitoring circuit and the signal transceiver module. The first energy conversion module has functions such as voltage boosting, voltage regulation, and charging management. The right side shows the piezoelectric power generation circuit, where a current source and capacitor connected in parallel represent the piezoelectric model. The positive and negative terminals of the four piezoelectric layers of the piezoelectric power generation structure are connected to a rectifier bridge circuit. The positive terminals of the rectifier bridge are connected in parallel and then connected to the second energy conversion module, with the negative terminals connected in parallel and then grounded. This embodiment uses the LTC3588 chip, and the VIN port of the second energy conversion module is also shown. After being processed by the LTC3588 chip, the voltage is connected in parallel with the output port of the BQ25570 chip through the VOUT port, and both are input to the energy storage module to power the temperature monitoring circuit and the signal transceiver module. The LTC3588 chip integrates a full-bridge rectifier, a high-efficiency synchronous buck converter, and intelligent power management logic, which can automatically manage the energy flow and achieve optimal energy distribution and system maintenance.

[0049] Figure 10 This is a schematic diagram of the energy harvesting circuit for electromagnetic and triboelectric power generation systems. The energy harvesting circuit for electromagnetic power generation is... Figure 9In a triboelectric power generation circuit, a voltage source and a capacitor connected in parallel represent the triboelectric model. Considering the extremely high impedance, high voltage, and extremely low current characteristics of triboelectric generators (TENGs), the LTC3331 is selected as the third energy conversion module. The positive and negative terminals of the two triboelectric energy harvesting devices are connected to the rectifier bridge circuit respectively. The positive terminals of the rectifier bridge are connected in parallel and then connected to the VIN port of the LTC3331, while the negative terminals are connected in parallel and grounded. After being processed by the LTC3331, the voltage is connected in parallel with the output port of the BQ25570 chip through the VOUT port, and both are input to the energy storage module to power the temperature monitoring circuit and the signal transceiver module. The LTC3331 is a nanometer-power-level energy harvesting power manager designed specifically for micropower sources. Its core advantages lie in its extremely low quiescent current and wide input voltage range, perfectly matching high-impedance energy sources such as triboelectric generators.

[0050] Temperature monitoring circuit and signal transceiver module, such as Figure 11 As shown, the temperature sensor uses a two-wire PT1000 temperature sensor, which has advantages such as high measurement accuracy, good stability, and excellent long-term repeatability. The temperature measurement range is typically -200°C to 850°C. When the temperature changes, the resistance value of the PT1000 changes, and the current brake disc temperature can be obtained by extracting its resistance value.

[0051] The signal transceiver module includes two wireless transceiver controllers as the transmitter and receiver. In this embodiment, the wireless transceiver controller specifically adopts the radio frequency controller CC430F5137.

[0052] A current source REF200 is connected to one end of the PT1000 temperature sensor output line to stabilize the current and establish a linear relationship between resistance and voltage. The voltage signal from the PT1000 temperature sensor is amplified by an operational amplifier and then input to the microprocessor. The microprocessor compares the obtained temperature data with a preset danger temperature threshold. When the temperature exceeds the limit or remains at a danger temperature, the microprocessor controls the RF controller CC430F5137 to send an alarm signal to the driver. The alarm signal is wirelessly transmitted to the RF controller in the driver's cab via antenna 10, and finally displayed on the display module along with the current temperature information and alarm status.

[0053] Figure 12This is a flowchart illustrating the operation of a self-powered integrated composite energy harvesting device. When a truck is moving or experiencing bumps, the suspension system experiences vibrations from the wheels and transmission mechanism. An energy harvesting device mounted on the suspension utilizes these vibrations to generate electricity. The vibration excites a piezoelectric cantilever beam, causing multiple piezoelectric modules to vibrate and generate electricity; simultaneously, it drives an array of magnets to move up and down, exciting multiple electromagnetic power generation modules to generate electricity. The output electrical signal is processed by a power management module, and the generated electrical energy is stored. In this way, vibration energy is converted into electrical energy, powering the temperature sensor and the wireless signal transmitter processor, achieving self-powering for the system. Through parameter design, the power generation device is effectively integrated with the truck suspension, and the generated electricity is used to charge and store capacitors, ultimately powering the entire temperature monitoring system.

[0054] Figure 13 This is a flowchart illustrating the workflow of temperature monitoring and wireless signal transmission / reception alarm feedback. During truck operation, frequent braking causes heat buildup on the brake discs. Given that trucks often use drum brakes with significant heat fade, this system mounts PT1000 temperature sensors on the brake disc surface to monitor the real-time temperature of each wheel. The real-time temperature is converted into an electrical signal and transmitted to the microprocessor. When the temperature of any wheel remains excessively high for an extended period or momentarily exceeds the acceptable range, the system generates an alarm. This alarm information is wirelessly transmitted to a display screen in the driver's cab via the radio frequency controller, showing the current temperature and alarm details, thus providing feedback to the driver so they can adjust their braking behavior or take other appropriate measures.

[0055] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A self-generating wireless freight car wheel hub temperature monitoring system, characterized in that, It includes a protective shell, an antenna (10), a signal processing module (20), a self-generating module (30), and a temperature sensor (60); the self-generating module (30) is fixed inside the protective shell, the protective shell is fixed to the truck axle (50) through mounting holes (40), the self-generating module (30) is connected to the signal processing module (20), and the temperature sensor (60) is mounted on the surface of the brake disc (70); The self-generating module (30) includes an electromagnetic power generation structure (01) and a piezoelectric power generation structure (02). The signal processing module (20) includes an energy conversion and storage circuit, a temperature monitoring circuit, and a signal transceiver module. The energy conversion and storage circuit converts and stores the energy generated by the self-generating module to power the entire system. The signal transceiver module includes two wireless transceiver controllers as a transmitter and a receiver. The transmitter is connected to an antenna (10). The temperature monitoring circuit is connected to a temperature sensor (60) to monitor the temperature and control the transmitter to send temperature information and warning signals to the receiver. The piezoelectric power generation structure (02) is a double-layer structure in the system, located on both sides of the electromagnetic power generation structure, and contains four sets of piezoelectric cantilever beams. The two piezoelectric cantilever beam structures of the piezoelectric power generation structure (02) on one side are symmetrical. A single piezoelectric cantilever beam structure consists of a spring (21), a base arch beam (22), a first mass block (23), a piezoelectric layer (24), and an excitation magnet (25). The base arch beam (22) is a semi-circular arch structure, and both ends of the arch extend outward along the diameter direction. One end of the base arch beam and the excitation magnet (25) are fixed to the two sides of the protective shell, respectively. The piezoelectric layer (24) is bonded to the outer surface of the base arch beam (22), and the side of the arch that protrudes outward is the outer side. The spring (21) is fixed between the inner surface of the other end of the base arch beam (22) and the protective shell. The first mass block (23) is fixed to the outer surface of the piezoelectric layer opposite to the fixed position of the spring (21). The piezoelectric power generation structure (02) is a double-layer structure in the system, located on both sides of the electromagnetic power generation structure. The piezoelectric power generation structure on one side is a windmill-shaped multi-directional piezoelectric energy collection device, including leaf springs (31), piezoelectric plates (32), windmill-shaped torsion beams (33), drive springs (34), and a second mass block (35). The four leaf springs (31) are respectively fixed to the ends of the four beams of the windmill-shaped torsion beams (33), and the other ends of the four leaf springs (31) are respectively connected to the four sides of the shell. The piezoelectric plates (32) are installed on the four beam surfaces of the windmill-shaped torsion beams (33), and the two ends of the drive springs (34) are respectively fixed to the center of the windmill-shaped torsion beams and the second mass block (35). The piezoelectric power generation structure (02) is replaced by a triboelectric energy harvesting device, which is a double-layer structure in the system, located on both sides of the electromagnetic power generation structure. The triboelectric energy harvesting device on one side includes a spring shaft, a triboelectric array magnet (16), an electrode layer (41), a mounting plate (42), a wire (43), and a triboelectric layer (44). The center of the spring shaft is fixed to the groove of the triboelectric array magnet (16), and the upper and lower ends are fixed to the reserved grooves on the upper and lower parts of the protective shell. Flexible substrates with equal spacing are fixed on the non-driving coil surfaces on the left and right sides of the triboelectric array magnet (16). The electrode layer (41) is pasted on the surface of the flexible substrate. The triboelectric layer (44) is composed of strips of polytetrafluoroethylene film with equal spacing, which is installed on the surface of the mounting plate (42). The strips of polytetrafluoroethylene film are connected by wires (43), and their width and spacing match the aluminum electrode layer (41). The energy conversion and storage circuit is as follows: the positive and negative poles of the four coils in the electromagnetic power generation structure are respectively connected to the rectifier bridge circuit, and then after being processed by the first energy conversion module, they are sent to the energy storage module. The positive and negative poles of the four piezoelectric layers of the piezoelectric power generation structure are respectively connected to the rectifier bridge circuit. After the positive poles of the rectifier bridge are connected in parallel, they are connected to the second energy conversion module. After processing, they are connected in parallel with the first energy conversion module and input to the energy storage module together.

2. A self-generating wireless temperature monitoring system for a truck wheel hub as defined in claim 1, wherein, The electromagnetic power generation structure (01) includes a central spring (11), an array magnet (12), a coil (13), and an iron core (14) located inside the coil (13). The central spring (11) is divided into two parts, with the middle part fixed to the array magnet (12) and the upper and lower ends fixed to the top and bottom of the protective shell. There are four coils (13), which are fixed on the side of the protective shell and evenly distributed around the two sides of the array magnet (12). The central spring (11) and the array magnet (12) constitute the mover, and the four sets of parallel coils (13) and the iron core (14) inside them constitute the stator.

3. A self-generating wireless freight car wheel hub temperature monitoring system according to claim 2, wherein, The energy conversion and storage circuit is as follows: the positive and negative poles of the four coils in the electromagnetic power generation structure are respectively connected to the rectifier bridge circuit, and then after being processed by the first energy conversion module, they are sent to the energy storage module. The positive and negative poles of the two triboelectric energy harvesting devices are respectively connected to the rectifier bridge circuit. After the positive poles of the rectifier bridge are connected in parallel, they are connected to the third energy conversion module. After processing, they are connected in parallel with the first energy conversion module and input to the energy storage module together.

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