Intelligent door lock based on piezoelectric sensing wireless charging

Abstract

The utility model discloses an intelligent door lock based on piezoelectric sensing wireless charging. The intelligent door lock comprises a lock body arranged in a door body, a power supply module, a transmitting coil, a receiving coil, a power receiving module, a battery, a microprocessor and a storage module, a fingerprint detection element, a pressure sensor, a gasket, a spring and a piezoelectric sensor are sequentially arranged in the same hollow cylinder in the lock body. The power supply module is electrically connected with the piezoelectric sensor and the transmitting coil. The transmitting coil and the receiving coil are in induction connection; the receiving coil is electrically connected with the power receiving module; the power receiving module is electrically connected with the battery; the microprocessor is electrically connected with the fingerprint detection element, the pressure sensor, the power supply module, the power receiving module and the battery; and the storage module is electrically connected with the microprocessor. According to the utility model, electric energy is generated through a piezoelectric technology or a vibration energy acquisition device, so that charging can be realized while pressing or charging can be realized while closing, complicated means such as a mobile phone and a USB (Universal Serial Bus) are not needed, the structure is simple, and convenience is realized.

Description

Technical Field

[0001] This utility model belongs to the field of smart door locks and relates to a smart door lock based on piezoelectric sensing wireless charging. Background Technology

[0002] Smart door locks, with their convenience, security, and intelligent features, have gradually become a highly sought-after product in the market. Smart door locks not only allow unlocking via fingerprint, password, and facial recognition, but also offer advanced functions such as remote control and alarm systems, greatly enhancing home security and convenience.

[0003] However, despite significant advancements in the functionality of smart locks, their power supply remains a key constraint to their development. Currently, most smart locks on the market still rely on battery power. While this method is inexpensive and easy to replace, the limited battery life necessitates users regularly monitoring battery levels and replacing them promptly, undoubtedly increasing both operating costs and time. Furthermore, in extreme situations, such as power outages or battery depletion, smart locks will lose their functionality, causing considerable inconvenience to users.

[0004] Wireless charging technology, with its contactless charging method, offers new possibilities for powering smart door locks. Currently, wireless charging technology mainly utilizes three principles: electromagnetic induction, radio waves, and resonance. Among these, electromagnetic induction technology is the most widely used due to its maturity and low cost. The basic principle of electromagnetic induction wireless charging is to pass an alternating current of a certain frequency through the primary coil, thereby inducing a current in the secondary coil and achieving wireless energy transmission. Therefore, the wireless charging device for a smart door lock consists of a transmitter base and a receiver. The transmitter base connects to the power supply, typically using a standard power plug, resulting in a single power supply method that is limited by the layout of power outlets in the room. The receiver connects to the smart door lock's battery, but due to limitations in typical room circuit design, the receiver and transmitter base are often far apart, leading to lower reliability of wireless energy transmission. This type of wireless charging device based on electromagnetic induction technology faces several problems and challenges:

[0005] First, the transmission efficiency of electromagnetic induction wireless charging technology is affected by many factors, such as the distance between coils, their relative positions, and the strength of the magnetic field. In smart door lock applications, due to the installation location and structural limitations of the lock, the distance between the receiver and the transmitter base is often difficult to achieve optimal performance, thus affecting the efficiency and reliability of wireless charging. Second, electromagnetic induction wireless charging technology typically requires an external power source, meaning that in emergency situations such as power outages, the wireless charging device will not function properly, thus failing to provide timely power replenishment for the smart door lock. Utility Model Content

[0006] The purpose of this invention is to provide a smart door lock based on piezoelectric sensing wireless charging. It uses piezoelectric technology and a piezoelectric sensor to wirelessly charge the smart door lock, eliminating the need for household circuit power supply and solving the problem of power shortage during power outages.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A smart door lock based on piezoelectric sensing and wireless charging is characterized by comprising: a lock body, a power supply module, a transmitting coil, a receiving coil, a power receiving module, a battery, a microprocessor, and a storage module disposed within the door body; wherein a fingerprint detection element, a pressure sensor, a gasket, a spring, and a piezoelectric sensor are sequentially disposed within the same hollow cylinder in the lock body; the power supply module is electrically connected to the piezoelectric sensor and the transmitting coil respectively; the transmitting coil and the receiving coil are inductively connected; the receiving coil is electrically connected to the power receiving module; the power receiving module is electrically connected to the battery; the microprocessor is electrically connected to the fingerprint detection element, the pressure sensor, the power supply module, the power receiving module, and the battery; and the storage module is electrically connected to the microprocessor.

[0009] As a further improvement of this utility model, elastic protrusions are provided on both sides of the gasket.

[0010] As a further improvement of this utility model, the hollow column is provided with outwardly extending limiting grooves on both sides to accommodate the elastic protrusions; a reset key is provided in each limiting groove to reset the elastic protrusions.

[0011] As a further improvement of this utility model, the power supply module includes at least one transistor, one relay, a first transmission line and a second transmission line; the base of the transistor is connected to the microprocessor, its collector is connected to the output terminal of the piezoelectric sensor, and its emitter is connected to the moving contact of the relay; one stationary contact of the relay is connected to the input terminal of the first transmission line, and the other stationary contact is connected to the input terminal of the second transmission line; the coil of the relay is electrically connected to the microprocessor.

[0012] As a further improvement of this utility model, the first transmission line includes at least one charge amplifier and a first impedance matching circuit; the inverting input terminal of the charge amplifier is connected to a stationary contact of the relay connected to the first transmission line, the positive input terminal of the charge amplifier is grounded, and the output terminal of the charge amplifier is connected to one end of the first impedance matching circuit; the transmitting coil is electrically connected to the other end of the first impedance matching circuit.

[0013] As a further improvement of this utility model, the second transmission line includes a second impedance matching circuit, one end of which is connected to a stationary contact of the relay connected to the second transmission line, and the other end of which is connected to the transmitting coil.

[0014] As a further improvement of this utility model, it also includes a vibration energy acquisition device; the vibration energy acquisition device is fixedly connected to the side of the door body near the door frame, located below the lock body; the vibration energy acquisition device is electrically connected to the power supply module.

[0015] As a further improvement of this utility model, the vibration energy harvesting device includes a cantilever beam, piezoelectric ceramics, and a mass block; one end of the cantilever beam is fixed to the side of the door body near the door frame, and the other end of the cantilever beam is fixed to the door body near the door frame; piezoelectric ceramics are arranged on both sides of the cantilever beam.

[0016] As a further improvement of this utility model, the input end of the second transmission line is connected to the vibration energy acquisition device, and the output end of the second transmission line is connected to the transmitting coil.

[0017] As a further improvement of this utility model, the vibration energy harvesting device also includes a mass block; the mass block is fixedly connected to the end of the cantilever beam away from the door frame.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] This invention distinguishes between pressing and closing the door using a pressure sensor, and collects the pressure on the door body using a piezoelectric sensor, converting it into electrical energy to provide a green and sustainable energy source for the lock. Simultaneously, a fingerprint detection element enhances the lock's security, ensuring that only authorized users can open it. By sequentially housing the fingerprint detection element, pressure sensor, gasket, spring, and piezoelectric sensor within the same hollow cylinder, the pressure is ensured to be transmitted sequentially. The gasket increases the force-bearing area, and the spring allows the gasket to return to its original position. This unified hollow cylinder design simplifies the lock's structure, reduces its size, and improves its integration and reliability. The microprocessor and storage module handle various functions and data of the lock, enhancing its intelligence level.

[0020] Furthermore, the elastic protrusions on both sides of the gasket can enhance the contact area and stability between the gasket and adjacent components.

[0021] Furthermore, the combination of the limiting groove and the reset button ensures that the elastic protrusion accurately resets after being pressed, thereby maintaining the normal working state of the door lock.

[0022] Furthermore, this power supply module design enables flexible control and distribution of the piezoelectric sensor's output power. The transistor, acting as a switching element, controls the circuit's on / off state according to microprocessor instructions, thereby achieving the acquisition and transmission of the piezoelectric sensor's output power. The relay is used to switch between different transmission lines, selecting the appropriate power supply path based on the door lock's operating status and requirements. This design improves the door lock's energy efficiency and flexibility, while also helping to protect the lock's circuitry and components from damage.

[0023] Furthermore, the second transmission line includes a charge amplifier and an impedance matching circuit. The charge amplifier amplifies the weak charge signal generated by the piezoelectric sensor, while the impedance matching circuit further ensures the stability and efficiency of energy transmission.

[0024] Furthermore, by adding a vibration energy harvesting device, the energy sources of the door lock can be further expanded, enabling wireless charging during normal door opening and closing, thereby improving the door lock's battery life and stability.

[0025] Furthermore, the combination of cantilever beams and piezoelectric ceramics can efficiently convert the mechanical energy generated by the vibration of the door into electrical energy. This design has the advantages of simple structure, ease of manufacture, and low cost.

[0026] Furthermore, the second transmission line is connected to the vibration energy harvesting device, which ensures that the electrical energy obtained from the vibration energy harvesting device can be efficiently transmitted to the transmitting coil, providing a stable energy source for the door lock.

[0027] Furthermore, the mass block can increase the vibration amplitude of the cantilever beam, thereby improving the energy conversion efficiency of the piezoelectric ceramic. This helps to provide more energy for the door lock. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the smart door lock structure described in Example 1;

[0029] Figure 2 A schematic diagram of the structure for achieving emergency charging;

[0030] Figure 3 Schematic diagram of the elastic protrusion;

[0031] Figure 4 This is a schematic diagram of multipath power transmission;

[0032] Figure 5 This is a schematic diagram of the smart door lock structure described in Example 2;

[0033] Figure 6 This is a schematic diagram of the vibration energy harvesting device in Example 2;

[0034] Figure 7This is a schematic diagram of a vibration energy harvesting device.

[0035] The components include: 1. Fingerprint detection element; 2. Pressure sensor; 3. Gasket; 4. Spring; 5. Piezoelectric sensor; 6. Power supply module; 7. Transmitting coil; 8. Receiving coil; 9. Power receiving module; 10. Battery; 11. Door body; 12. Elastic protrusion; 13. Limiting groove; 14. Reset button; 15. Microprocessor; 16. First transmission line; 17. Second transmission line; 18. Cantilever beam; 19. Piezoelectric ceramic; 20. Mass block; 21. Base battery. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0037] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] This invention proposes a smart door lock based on piezoelectric sensing wireless charging. It utilizes electromagnetic induction wireless charging technology combined with piezoelectric technology, employing a piezoelectric sensor to collect electrical energy for wireless charging. When the door is closed normally, the pressure generated causes the piezoelectric sensor material to generate an electrical charge on its surface. This charge is amplified and used for power output, enabling wireless charging. Furthermore, in emergency situations where the smart door lock's battery is low and fingerprint recognition cannot be activated, pressing a finger on the fingerprint button to a specific position transmits pressure to the piezoelectric sensor, generating electrical energy for rapid charging and enabling the smart door lock to recognize fingerprints and unlock the door. It should be noted that under normal circumstances, the pressure applied during fingerprint unlocking can also be converted into stored electrical energy.

[0040] Example 1

[0041] like Figure 1 The smart door lock shown in Embodiment 1 includes a lock body, a power supply module 6, a transmitting coil 7, a receiving coil 8, a power receiving module 9, a battery 10, a microprocessor 15, and a storage module, all housed within the door body 11. The lock body is sequentially equipped with a fingerprint detection element 1, a pressure sensor 2, a gasket 3, a spring 4, and a piezoelectric sensor 5. The power supply module 6 is electrically connected to the piezoelectric sensor 5 and the transmitting coil 7, respectively.

[0042] The fingerprint detection element 1, the pad 3, the spring 4, and the piezoelectric sensor 5 are housed within a hollow cylinder, such as... Figure 2 As shown. The gasket 3 has elastic protrusions 12 on both sides facing each other, as... Figure 3 As shown, the elastic protrusion 12 is an elastic component, which is set to a small deformation state within the hollow cylinder. Therefore, when the gasket 3 compresses the spring 4 to the position of the limiting groove 13, the elastic protrusion 12 can recover its deformation and engage with the limiting groove 13. The reset button 14 is movably embedded in the limiting groove 13. Pressing the reset buttons 14 on both sides causes the elastic protrusion 12 to exit the limiting groove 13, thereby pushing the gasket 3 back to its original position under the action of the spring 4 recovering its deformation.

[0043] The power supply module 6 includes at least one transistor, one relay, a first transmission line 16, and a second transmission line 17. The base of the transistor is connected to the microprocessor 15, its collector is connected to the output terminal of the piezoelectric sensor 5, and its emitter is connected to the moving contact of the relay. One stationary contact of the relay is connected to the input terminal of the first transmission line 16, and the other stationary contact is connected to the input terminal of the second transmission line 17. The coil of the relay is electrically connected to the microprocessor 15. The transmitting coil 7 and the receiving coil 8 are inductively connected. The receiving coil 8 is electrically connected to the power receiving module 9. The power receiving module 9 is electrically connected to the battery 10. The microprocessor 15 is electrically connected to the fingerprint detection element 1, the pressure sensor 2, the power supply module 6, the power receiving module 9, and the battery 10. The storage module is electrically connected to the microprocessor 15. The battery 10 provides kinetic energy for opening and closing the lock body.

[0044] The power supply module 6 includes a relay, a transistor, a first transmission line 16, and a second transmission line 17. For example... Figure 4 As shown, the two stationary contacts of relay S1 are connected to the first transmission line 16 and the second transmission line 17 respectively. Its coil receives a trigger signal, thereby switching the moving contact of relay S1 from one stationary contact to the other. The base of the transistor receives the trigger signal, its collector is connected to the output terminal of the piezoelectric sensor 5, and its emitter is connected to the two stationary contacts of relay S1 respectively. The power supply module 6 may also include a base battery 21; the base battery 21 can provide bias voltage to the transistor; the base battery 21 may also be replaced by the electrical connection of battery 10.

[0045] The first transmission line 16 includes a charge amplifier and an impedance matching circuit. The inverting input of the charge amplifier is connected to a stationary contact of the relay S1, the positive input is grounded, and the output is connected to the impedance matching circuit.

[0046] The piezoelectric sensor 5 can also be connected to a measuring circuit to measure the amount of charge converted from pressure. The input terminal of the measuring circuit is connected to the input terminal of the piezoelectric sensor 5, and the output terminal of the measuring circuit is connected to the transmitting coil 7.

[0047] The second transmission line 17 includes a second impedance matching circuit. One end of the second impedance matching circuit is connected to a stationary contact of the relay S1 connected to the second transmission line 17, and the other end of the second impedance matching circuit is connected to the transmitting coil 7.

[0048] The power receiving module 9 includes a filter circuit and a battery management module. One end of the filter circuit is electrically connected to the receiving coil 8, and the other end is electrically connected to the battery management module. The battery management module is also connected to the battery 10.

[0049] The microcontroller 15 receives fingerprint information collected by the fingerprint detection element 1 and determines whether the received fingerprint matches the fingerprint already stored in the storage module. Simultaneously, the microcontroller 15 also monitors the real-time battery level of the battery 10. When the battery level of the battery 10 falls below a set threshold, it prompts the user to charge the battery promptly via the smart lock's display screen. Furthermore, the microcontroller 15 is connected to both the relay coil and the base of the transistor, receiving measurement signals from the pressure sensor 2 and outputting corresponding trigger levels to the relay S1 based on the measurement signals. In this embodiment, the microcontroller is an STM32L4A6AG, utilizing its low-power characteristics to reduce energy consumption.

[0050] The working principle of this embodiment is as follows:

[0051] Since the piezoelectric sensor 5 is located below the fingerprint detection element 1, the pressure generated by pressing the fingerprint detection element 1 during daily unlocking can be conducted to the piezoelectric sensor 5, causing the surface of the piezoelectric material to generate an electric charge after being subjected to force. In addition, the pressure generated when closing the door can be conducted to the piezoelectric sensor 5, causing the surface of the piezoelectric sensor 5 material to generate an electric charge after being subjected to force.

[0052] It is important to note that the pressure generated when closing a door is significantly greater than the pressure generated during normal fingerprint unlocking. The signals measured by pressure sensor 2 under these two usage conditions show a significant difference. Therefore, the microprocessor 15 can be configured to output different trigger levels based on this difference. Specifically, the experimental values ​​measured by pressure sensor 2 are recorded under both door closing and fingerprint unlocking pressure conditions. The average of multiple experimental values ​​is taken (considering individual differences in pressure, significant deviations in the data can be removed). The resulting fingerprint decompression threshold and door closing threshold can then be stored.

[0053] like Figure 4 As shown, when the measurement signal of pressure sensor 2 is greater than the fingerprint unlock threshold and less than the door closing threshold, microprocessor 15 outputs a low trigger level to relay S1. The relay coil is not energized, and its moving contact does not operate. At this time, the electrical energy output by piezoelectric sensor 5 is transmitted to transmitting coil 7 sequentially through transistor and first transmission line 16. When the measurement signal of pressure sensor 2 is greater than the door closing threshold, microprocessor 15 outputs a high trigger level to relay S1. The relay coil is energized, and its moving contact is triggered to switch to another stationary contact. At this time, the electrical energy output by piezoelectric sensor 5 is transmitted to transmitting coil 7 sequentially through transistor and second transmission line 17. Specifically, when the measurement signal of pressure sensor 2 is greater than either the fingerprint decompression threshold or the door closing threshold, microprocessor 15 outputs a high level to the base of transistor, turning on transistor and thus transmitting electrical energy from piezoelectric sensor 5.

[0054] Furthermore, when the battery 10 is low on power, the fingerprint detection element 1 can be pressed firmly until feedback vibration is received when the elastic protrusion 12 engages with the limiting groove 13. At this point, the pressure is transmitted to the piezoelectric sensor 5, reaching its maximum charge output. Pressing the reset button 14 resets the pad 3, and then repeating the pressing operation until the battery 10 is fully charged. The battery status can also be displayed on the screen. The spring deformation corresponding to the maximum charge output of the piezoelectric sensor 5, i.e., the position of the limiting groove 13, can be pre-measured experimentally. This charge output represents the maximum amount of electricity that can be generated by pressing in an emergency, and can characterize the strength of the electricity generated by pressing.

[0055] This method can be used to power battery 10 when it is depleted.

[0056] In this embodiment, an additional power supply can be provided for the pressure sensor 2 and the charge amplifier in the first transmission line 16.

[0057] Example 2

[0058] Compared to Example 1, Example 2 omits the pressure sensor 2. For example... Figure 5 As shown, the smart door lock proposed in Embodiment 2 includes a lock body, a power supply module 6, a transmitting coil 7, a receiving coil 8, a power receiving module 9, a battery 10, a microprocessor 15, and a storage module disposed inside the door body 11; a fingerprint detection element 1, a gasket 3, a spring 4, and a piezoelectric sensor 5 are sequentially disposed on the lock body; the power supply module 6 is electrically connected to the piezoelectric sensor 5 and the transmitting coil 7 respectively;

[0059] The power supply module 6 includes at least one transistor, one relay S1, a first transmission line 16, and a second transmission line 17. The base of the transistor is connected to the microprocessor 15, its collector is connected to the output terminal of the piezoelectric sensor 5, and its emitter is connected to the moving contact of the relay S1. One stationary contact of the relay S1 is connected to the input terminal of the first transmission line 16, and the other stationary contact is connected to the input terminal of the second transmission line 17. The coil of the relay S1 is electrically connected to the microprocessor 15. The transmitting coil 7 and the receiving coil 8 are inductively connected. The receiving coil 8 is electrically connected to the power receiving module 9. The power receiving module 9 is electrically connected to the battery 10. The microprocessor 15 is electrically connected to the fingerprint detection element 1, the power supply module 6, the power receiving module 9, and the battery 10. The storage module is electrically connected to the microprocessor 15.

[0060] Compared to Example 1, Example 2 further includes a vibration energy harvesting device, which comprises a microcantilever beam 18, a piezoelectric ceramic 19, and a mass block 20, such as... Figure 6 As shown, this is used to collect the vibration energy generated when the door closes and convert it into electrical energy for storage. Specifically, as... Figure 7As shown, one end of the cantilever beam 18 is fixed to the side of the door body 11 near the door frame and located below the lock body, while the other end of the cantilever beam 18 is fixedly connected to the mass block 20. Piezoelectric ceramics 19 are provided on both sides of the cantilever beam 18 to maximize the collection of vibration energy generated when the door is closed. The cantilever beam 18 is installed below the lock body, which is closer to the point of force exerted when a person closes the door, thus facilitating the maximum collection of vibration energy.

[0061] The power supply module 6 includes a first transmission line 16 and a second transmission line 17, wherein the first transmission line 16 is connected to the piezoelectric sensor 5 and the second transmission line 17 is connected to the vibration energy acquisition device.

[0062] The power receiving module 9 includes a filter circuit and a battery management module. One end of the filter circuit is electrically connected to the receiving coil 8, and the other end is electrically connected to the battery management module. The battery management module is also connected to the battery 10.

[0063] The working principle of this embodiment is as follows:

[0064] During routine fingerprint unlocking, pressing the fingerprint detection element 1 causes the piezoelectric material of the piezoelectric sensor 5 to generate an electric charge on its surface after being subjected to force. The generated charge is transmitted to the transmitting coil 7 through the first transmission line 16. When closing the door, the resulting vibration causes the mass block 20 to vibrate, which in turn causes the cantilever beam 18 to vibrate, thereby deforming the piezoelectric ceramics 19 on both sides of the cantilever beam 18 to generate an electric charge. The generated charge is transmitted to the transmitting coil 7 through the second transmission line 17.

[0065] Furthermore, when the battery 10 is low on power, the fingerprint detection element 1 can be pressed firmly until feedback vibration is received when the elastic protrusion 12 engages with the limiting groove 13. At this point, the pressure is transmitted to the piezoelectric sensor 5, reaching its maximum charge output. Pressing the reset button 14 resets the pad 3, and then repeating the pressing operation until the battery 10 is fully charged. The battery status can also be displayed on the screen. The spring deformation corresponding to the maximum charge output of the piezoelectric sensor 5, i.e., the position of the limiting groove 13, can be pre-measured experimentally. This method can be used to power the battery 10 when it is depleted.

[0066] In this embodiment, an additional power supply can be provided for the charge amplifier in the first transmission line 16.

[0067] Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the foregoing description. Therefore, the scope of this teaching should not be determined by reference to the foregoing description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed utility model subject matter.

[0068] The above content provides a further detailed description of this utility model. It should not be considered that the specific embodiments of this utility model are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of this utility model, and all such deductions or substitutions should be considered to fall within the scope of protection of this utility model as defined by the submitted claims.

Claims

1. A smart door lock based on piezoelectric sensing and wireless charging, characterized in that, include: The lock body, power supply module (6), transmitting coil (7), receiving coil (8), power receiving module (9), battery (10), microprocessor (15) and storage module are installed in the door body (11); The lock body contains a fingerprint detection element (1), a pressure sensor (2), a gasket (3), a spring (4), and a piezoelectric sensor (5) arranged sequentially within the same hollow cylinder. The power supply module (6) is electrically connected to the piezoelectric sensor (5) and the transmitting coil (7); the transmitting coil (7) and the receiving coil (8) are inductively connected. The receiving coil (8) is electrically connected to the power receiving module (9); the power receiving module (9) is electrically connected to the battery (10); The microprocessor (15) is electrically connected to the fingerprint detection element (1), pressure sensor (2), power supply module (6), power receiving module (9) and battery (10); the storage module is electrically connected to the microprocessor (15).

2. The smart door lock based on piezoelectric sensing and wireless charging according to claim 1, characterized in that, The gasket (3) has elastic protrusions (12) on both sides opposite to each other.

3. A smart door lock based on piezoelectric sensing and wireless charging according to claim 2, characterized in that, The hollow column has outwardly extending limiting grooves (13) on both sides to accommodate the elastic protrusion (12); each limiting groove (13) is provided with a reset key (14) to reset the elastic protrusion (12).

4. A smart door lock based on piezoelectric sensing and wireless charging according to claim 1, characterized in that, The power supply module (6) includes at least one transistor, a relay, a first transmission line (16), and a second transmission line (17); the base of the transistor is connected to the microprocessor (15), its collector is connected to the output terminal of the piezoelectric sensor (5), and its emitter is connected to the moving contact of the relay; one stationary contact of the relay is connected to the input terminal of the first transmission line (16), and the other stationary contact is connected to the input terminal of the second transmission line (17); the coil of the relay is electrically connected to the microprocessor (15).

5. A smart door lock based on piezoelectric sensing and wireless charging according to claim 4, characterized in that, The first transmission line (16) includes at least one charge amplifier and a first impedance matching circuit; the inverting input terminal of the charge amplifier is connected to a stationary contact of the relay connected to the first transmission line (16), the positive input terminal of the charge amplifier is grounded, and the output terminal of the charge amplifier is connected to one end of the first impedance matching circuit; the transmitting coil (7) is electrically connected to the other end of the first impedance matching circuit.

6. A smart door lock based on piezoelectric sensing and wireless charging according to claim 4, characterized in that, The second transmission line (17) includes a second impedance matching circuit. One end of the second impedance matching circuit is connected to a stationary contact of the relay connected to the second transmission line (17), and the other end of the second impedance matching circuit is connected to the transmitting coil (7).

7. A smart door lock based on piezoelectric sensing wireless charging according to claim 6, characterized in that, It also includes a vibration energy acquisition device; the vibration energy acquisition device is fixedly connected to the door body (11) on the side near the door frame, located below the lock body; the vibration energy acquisition device is electrically connected to the power supply module (6).

8. A smart door lock based on piezoelectric sensing and wireless charging according to claim 7, characterized in that, The vibration energy harvesting device includes a cantilever beam (18) and piezoelectric ceramics (19); one end of the cantilever beam (18) is fixed to the door body (11) near the door frame; piezoelectric ceramics (19) are provided on both sides of the cantilever beam (18).

9. A smart door lock based on piezoelectric sensing and wireless charging according to claim 8, characterized in that, The input end of the second transmission line (17) is connected to the vibration energy acquisition device, and the output end of the second transmission line (17) is connected to the transmitting coil (7).

10. A smart door lock based on piezoelectric sensing and wireless charging according to claim 7, characterized in that, The vibration energy harvesting device also includes a mass block (20); the mass block (20) is fixedly connected to the end of the cantilever beam (18) away from the door frame.

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