Piezoelectric-electromagnetic composite energy collection device for road vehicle type self-detection

Abstract

The invention provides a piezoelectric-electromagnetic composite energy collection device for road vehicle type self-detection, and relates to the technical field of energy recycling. The device comprises an energy harvesting device and a detection device. The energy harvesting device mainly comprises a piezoelectric module, an electromagnetic module, a hinge, a connecting rod, a base, a sliding block and a main spring. The initial state of the piezoelectric module is arched, and a main spring is arranged below the piezoelectric module; the sliding block is fixed on the hinge at the bottom of the arch structure and the base; the electromagnetic modules are symmetrically distributed on the two sides of the piezoelectric module, and each electromagnetic module comprises a coil, a permanent magnet and an auxiliary spring; the detection device comprises an energy collection circuit and a wireless communication module. According to the invention, the electric energy collected by the energy harvesting device is firstly stored and then is supplied to the detection device, the detection device judges the passing vehicle type according to the magnitude of the generated voltage, and finally the wireless communication module transmits the identified vehicle type signal to the cloud, so that self-power supply and road vehicle type detection are realized.

Description

Technical Field

[0001] The invention relates to the technical field of energy recovery and utilization, and in particular to a piezoelectric-electromagnetic composite energy collection device for road vehicle self-detection. Background Art

[0002] Roads are the foundation of transportation. They are the transportation carriers of people and logistics generated by social and economic activities. They are responsible for the transfer and distribution of traffic within cities and between cities. In recent years, some micro wireless electronic devices such as speedometers and rangefinders have been widely used to maintain road traffic. However, with the use of these low-power electronic devices, traditional batteries have exposed more and more problems, such as small capacity, easy explosion, and inability to replace in time, which seriously affects traffic order. Therefore, how to make these devices effectively self-powered has become one of the problems that need to be solved urgently.

[0003] In this context, the abundant renewable energy in the environment has received extensive attention from researchers. These green energies, such as mechanical energy, light energy and thermal energy, are gradually becoming an important source of power for sensors. Through innovative technologies, we can extract electrical energy from dynamic energy such as mechanical vibration and motion in the environment, or directly use solar panels and thermal energy conversion devices to capture light energy and thermal energy to provide stable and continuous power support for sensors. Piezoelectric structures and electromagnetic structures have been experimentally verified as the preferred solutions for efficiently converting mechanical vibration energy.

[0004] However, most traditional energy harvesting devices are based on cantilever beam designs. Limited by the characteristics and size of piezoelectric materials, these devices often have a high resonant frequency and can only perform optimally in a narrow frequency band close to this frequency point. At the same time, the energy collection and power supply of existing energy harvesting devices are separated from the signal detection output of the sensor, lacking integration, and not truly integrated with the Internet of Things system. Therefore, exploring how to achieve efficient energy harvesting in ultra-low frequency vibration environments, and how to integrate energy harvesting and detection and apply them to environmentally friendly self-powered wireless sensors have become the mainstream research directions in the current field. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a piezoelectric-electromagnetic composite energy harvesting device for road vehicle model self-detection, which broadens the working frequency band and increases the output power by mixing piezoelectric energy capture and electromagnetic energy capture, and judges the type of vehicle passing through the speed bump by the voltage actually generated by the device, and then combines with the LoRa communication module to transmit the identified vehicle data to the cloud in real time, realizing the true integration of piezoelectric energy capture technology and Internet of Things communication technology.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a piezoelectric-electromagnetic composite energy harvesting device for road vehicle self-detection, comprising an energy harvesting device and a detection device, wherein the energy harvesting device comprises a piezoelectric module, an electromagnetic module, a first hinge, a connecting rod, a base, a slider and a main spring; The piezoelectric module includes a PVDF film in a round arch shape, the first hinge is located above the PVDF film, the two connecting rods are connected by the first hinge, the connecting rod is connected to the slider by the second hinge, the slider is slidably connected to the base, the upper end of the main spring is connected to the PVDF film, the lower end of the main spring is fixed to the base, and the slider is connected to the end of the PVDF film by a horizontal connecting rod; The electromagnetic module includes a coil, a permanent magnet and a secondary spring, wherein the permanent magnet is arranged inside the coil, one end of the secondary spring is connected to the permanent magnet, and the other end of the secondary spring is connected to the magnetic pad; The detection device includes an energy collection circuit and a wireless communication module. The energy collection circuit includes a rectifier bridge, a capacitor, a voltage monitoring circuit and a voltage stabilizing circuit; the wireless communication module includes two LoRa modules.

[0007] As a preferred solution of the present invention, the stiffness coefficients of the main spring and the auxiliary spring are 20N / Kg and 100N / Kg respectively, and the length of the main spring is 10cm.

[0008] As a preferred solution of the present invention, the end of the PVDF film is fixed to the transverse connecting rod by strong adhesive.

[0009] As a preferred solution of the present invention, the outputs of the piezoelectric module and the electromagnetic module of the energy capture device are independently led out and connected to a rectifier bridge to form a parallel circuit, and then connected to an energy collection circuit.

[0010] As a preferred solution of the present invention, the input side of the rectifier bridge is connected to the energy capture device, and the output side of the rectifier bridge is connected to the super capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 This is a schematic diagram of the working principle.

[0012] Figure numerals: 1. hinge; 2. connecting rod; 3. PVDF film; 4. main spring; 5. auxiliary spring; 6. permanent magnet; 7. coil; 8. magnetic gasket; 9. slider; 10. base; 11. LoRa module; 12. speed bump; 13. horizontal connecting rod. DETAILED DESCRIPTION

[0013] The specific implementation modes of the present invention are further described below in conjunction with the accompanying drawings to make the technical solutions of the present invention easier to understand and grasp.

[0014] A piezoelectric-electromagnetic composite energy harvesting device for road vehicle self-detection, such as Figure 1 As shown, it includes two parts: an energy capture device and a detection device. The energy capture device mainly includes a piezoelectric module, an electromagnetic module, a hinge 1, a connecting rod 2, a base 10, a slider 9 and a main spring 4.

[0015] The piezoelectric module includes a PVDF film 3, a beryllium bronze substrate and a conductive silver paste. The beryllium bronze substrate and the conductive silver paste are fixed on the PVDF film 3, and the natural state of the PVDF film 3 is a round arch. The upper ends of the two connecting rods 2 are connected by a hinge 1, and the lower ends of the connecting rods 2 are hinged with a horizontal connecting rod 13 to form an arch structure. The two ends of the PVDF film 3 are fixedly connected to the two horizontal connecting rods 13 respectively.

[0016] The upper end of the main spring 4 is fixedly connected to the PVDF film 3, and the lower end of the main spring 4 is fixed to the middle of the bottom base 10; the slider 9 is placed symmetrically along the axis of the main spring 4, the slider 9 is slidably connected to the base 10, and the slider 9 is fixedly connected to the transverse connecting rod 13.

[0017] The electromagnetic module is symmetrically distributed at both ends of the piezoelectric module, including a coil 7, a permanent magnet 6 and a secondary spring 5. The coil 7 is cylindrical, and the permanent magnet 6 is arranged inside the coil 7. The two ends of the secondary spring 5 are fixedly connected to the magnetic pad 8 and the permanent magnet 6 respectively, and the center lines of the coil 7, the permanent magnet 6 and the secondary spring 5 are all on the same straight line.

[0018] The detection device mainly includes an energy collection circuit and a wireless communication module. The energy collection circuit includes a rectifier bridge, a capacitor, a voltage monitoring circuit and a voltage stabilization circuit; the wireless communication module includes two LoRa modules 11, which have the characteristics of low power consumption, long-distance communication, strong anti-interference, etc. The communication chip of the LoRa module 11 is SX127x.

[0019] Working process: Figure 2 As shown, when placed under the speed bump 12, the passing vehicles will give a vertical downward force to the top of the connecting rod 2, causing the PVDF film 3 to deform, causing the PVDF film 3 to deform from the initial arched state to the horizontal state, generating electric charge.

[0020] Furthermore, the connecting rod 2 compresses the main spring 4 and the auxiliary spring 5. Under the action of the elastic force, the permanent magnet 6 begins to make reciprocating horizontal motion in the coil 7, causing the magnetic flux in the coil 7 to change, thereby generating electricity through electromagnetic induction. When the connecting rod 2 is released from the extrusion, the elastic potential energy stored in the main spring 4 first restores the PVDF film 3 to its initial state, causing the energy capture device to generate electricity in the opposite direction; then, due to the rebound movement of the main spring 4, the PVDF film 3 will continue to deform, and the above process will be repeated until the main spring 4 tends to stabilize to achieve continuous power generation. The generated electrical energy is collected by the rectifier bridge voltage stabilization circuit to power the LoRa communication module 11 and the battery on the main control board.

[0021] Since different types of vehicles have different wheel curvatures and front and rear wheel spacings, these two variables will affect the rebound performance of the main spring and thus change the output voltage of the device. Therefore, when different types of vehicles pass through the speed bumps 12 equipped with an energy capture device, different signals will be generated. Experiments have shown that these signals have a very high degree of recognition and can be directly used to identify vehicle models.

[0022] Finally, the recognition results are transmitted to the cloud, realizing the self-power supply and self-sensing functions of the energy harvester. The device has a simple structure, is easy to design and install, and can accurately identify vehicle models. It makes up for the shortcomings of existing road energy harvesting devices, such as the difficulty in collecting low-frequency vibration signals and the low energy harvesting efficiency, and also realizes the high integration of the energy harvesting device and the detection sensor.

[0023] Of course, the above are only typical examples of the present invention. In addition, the present invention may also have many other specific implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A piezoelectric-electromagnetic composite energy harvesting device for road vehicle self-detection, characterized in that: It comprises an energy capture device and a detection device, wherein the energy capture device comprises a piezoelectric module, an electromagnetic module, a first hinge (1), a connecting rod (2), a base (10), a slider (9) and a main spring (4); The piezoelectric module comprises a PVDF film (3) in a circular arch shape, the first hinge (1) is located above the PVDF film (3), the two connecting rods (2) are connected via the first hinge (1), the connecting rod (2) is connected to a slider (9) via a second hinge (1), the slider (9) is slidably connected to a base (10), the upper end of the main spring (4) is connected to the PVDF film (3), the lower end of the main spring (4) is fixed to the base (10), and the slider (9) is connected to the end of the PVDF film (3) via a transverse connecting rod (13); The electromagnetic module comprises a coil (7), a permanent magnet (6) and a secondary spring (5), wherein the permanent magnet (6) is arranged inside the coil (7), one end of the secondary spring (5) is connected to the permanent magnet (6), and the other end of the secondary spring (5) is connected to a magnetic pad (8); The detection device comprises an energy collection circuit and a wireless communication module, wherein the energy collection circuit comprises a rectifier bridge, a capacitor, a voltage monitoring circuit and a voltage stabilizing circuit; and the wireless communication module comprises two LoRa modules (11).

2. A piezoelectric-electromagnetic composite energy harvesting device for road vehicle self-detection according to claim 1, characterized in that: The stiffness coefficients of the main spring (4) and the auxiliary spring (5) are 20 N / Kg and 100 N / Kg respectively, and the length of the main spring (4) is 10 cm.

3. The piezoelectric-electromagnetic composite energy harvesting device for road vehicle self-detection according to claim 1 is characterized by: The end of the PVDF film (3) is fixed to the transverse connecting rod (13) by strong adhesive.

4. The piezoelectric-electromagnetic composite energy harvesting device for road vehicle self-detection according to claim 1 is characterized by: The outputs of the piezoelectric module and the electromagnetic module of the energy capture device are independently led out and connected to a rectifier bridge to form a parallel circuit, and then connected to an energy collection circuit.

5. The piezoelectric-electromagnetic composite energy harvesting device for road vehicle self-detection according to claim 1, characterized in that: The input side of the rectifier bridge is connected to the energy capture device, and the output side of the rectifier bridge is connected to the super capacitor.

Images