Intelligent door lock control circuit based on fingerprint identification and intelligent door lock

Abstract

The utility model provides an intelligent door lock control circuit based on fingerprint identification and an intelligent door lock. The intelligent door lock control circuit based on fingerprint identification comprises a front fingerprint module, a rear fingerprint module and a rear fingerprint module, wherein the front fingerprint module is used for outputting a matching control signal when acquired information is matched with unlocking fingerprint information; the rear fingerprint module is used for outputting a matching control signal when the acquired information is matched with the unlocking fingerprint information; the front lock main board module is connected with the front fingerprint module and the rear fingerprint module and used for driving the lock body to conduct unlocking. The rear lock main board module is connected with the front lock main board module and used for outputting a rear clutch control signal when receiving a rear lock unlocking signal output by the front lock main board module. According to the intelligent door lock control circuit based on fingerprint identification, the fingerprint modules are arranged on the front lock assembly and the rear lock assembly respectively and control the clutch motors on the two sides of the front lock and the rear lock respectively, and bidirectional safety protection is achieved.

Description

Technical Field

[0001] This utility model relates to the field of smart door lock technology, and in particular to a smart door lock control circuit and smart door lock based on fingerprint recognition. Background Technology

[0002] Fingerprint biometrics is a biometric technology that analyzes the unique patterns of human skin texture for identity verification and recognition. Its core principle is that each person's fingerprint is unique and remains unchanged throughout their life; even the fingerprints of two fingers of the same person will differ. A fingerprint recognition system mainly includes fingerprint image acquisition, preprocessing, feature extraction, and template matching. Algorithms are used to compare fingerprint images to determine if a match exists. With technological advancements, fingerprint recognition has gradually become widely used in consumer electronics and industrial equipment. The technology has matured and stabilized, and it is also widely applied in the smart lock industry, becoming an indispensable part of production and daily life.

[0003] Fingerprint biometric technology is widely used in the smart lock industry for identity verification. To ensure indoor security, existing smart locks typically use a single-sided identity verification key to control entry from outside. Unlocking from inside to outside does not require a key; instead, it is done via a mechanical or sensor switch. Therefore, in certain scenarios with high security requirements, smart locks with single-sided identity verification key verification pose certain security risks.

[0004] Therefore, existing technologies still need to be improved and developed. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a smart door lock control circuit and smart door lock based on fingerprint recognition, so as to solve the problem that the existing smart door locks based on fingerprint recognition can only perform fingerprint recognition verification on one side of the door lock, resulting in insufficient security.

[0006] The technical solution of this utility model is as follows:

[0007] In a first aspect, this utility model provides a smart door lock control circuit based on fingerprint recognition, comprising a front locking assembly, a rear locking assembly, and a lock body: the front locking assembly includes a front fingerprint module, a front lock mainboard module, and a front clutch motor; the rear locking assembly includes a rear fingerprint module, a rear lock mainboard module, and a rear clutch motor; wherein,

[0008] The front fingerprint module is used to set the recorded fingerprint information as the front unlocking fingerprint information, and to output a matching control signal when the collected current fingerprint information matches the front unlocking fingerprint information.

[0009] The rear fingerprint module is used to set the recorded fingerprint information as the rear unlocking fingerprint information, and to output a matching control signal when the collected current fingerprint information matches the rear unlocking fingerprint information.

[0010] The front lock mainboard module is connected to the front fingerprint module and the rear fingerprint module respectively. It is used to output a front clutch control signal to control the working state of the front clutch motor when receiving the matching control signal output by the front fingerprint module; and to output a rear lock unlocking signal when receiving the matching control signal output by the rear fingerprint module.

[0011] The front clutch motor is connected to the front lock main board module and the lock body respectively, and is used to receive the front clutch control signal and drive the lock body to unlock;

[0012] The rear lock motherboard module is connected to the front lock motherboard module and is used to send or receive unlocking fingerprint information to the front lock motherboard module via a serial port, and to output a rear clutch control signal when receiving the rear lock unlocking signal output by the front lock motherboard module.

[0013] The rear clutch motor is connected to the rear lock main board module and the lock body respectively, and is used to receive the rear clutch control signal and drive the lock body to unlock.

[0014] In a further embodiment of this invention, the front locking motherboard module includes: a rear main control chip, a front clock circuit, and a front clutch motor drive circuit; wherein,

[0015] The rear main control chip is connected to the front fingerprint module and is used to output rear unlocking fingerprint information from the rear fingerprint module to the front fingerprint module, or to receive and output front unlocking fingerprint information from the front fingerprint module to the rear fingerprint module; or to receive matching control signals from the front fingerprint module or the rear fingerprint module: when the matching control signal comes from the front fingerprint module, the rear main control chip outputs a front clutch motor drive signal; when the matching control signal comes from the rear fingerprint module, the rear main control chip outputs a rear lock unlocking signal;

[0016] The front clock circuit is connected to the front main control chip and is used to provide clock synchronization information;

[0017] The front clutch motor drive circuit is connected to the front main control chip and is used to drive the front clutch motor to work according to the front clutch motor drive signal.

[0018] In a further embodiment of this invention, the rear lock motherboard module includes: a rear main control chip, a rear clock circuit, and a rear clutch motor drive circuit; wherein,

[0019] A further feature of this invention includes a voltage regulator circuit, which is connected to an external power supply voltage and is connected to the power supply voltage terminals of the rear main control chip and the front main control chip, respectively, for stepping down and regulating the power supply voltage to the operating voltage, which is used to power the rear main control chip and the front main control chip, respectively.

[0020] In a further embodiment of this invention, the front lock motherboard module further includes a front voltage regulator circuit, and the rear lock motherboard module further includes a rear voltage regulator circuit. The front and rear voltage regulator circuits are respectively connected to an external power supply voltage. The front voltage regulator circuit is used to step down and regulate the power supply voltage to the front lock operating voltage, which is used to power the front main control chip. The rear voltage regulator circuit is used to step down and regulate the power supply voltage to the rear lock operating voltage, which is used to power the rear main control chip.

[0021] In a further embodiment of this invention, the voltage regulator circuit includes: a first inductor, a second inductor, a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, and a buck regulator chip; wherein,

[0022] One end of the first inductor is connected to the power supply voltage, and the other end of the first inductor is connected to the power supply terminal and the enable terminal of the buck regulator chip, respectively. One end of the first capacitor, one end of the second capacitor, and one end of the third capacitor are connected to the power supply terminal of the buck regulator chip, and the other ends of the first capacitor, the second capacitor, and the third capacitor are grounded. The mode selection terminal of the buck regulator chip is connected to one end of the first resistor, the other end of the first resistor is grounded, and the ground terminal of the buck regulator chip is grounded. The switch control terminal of the buck regulator chip is connected to one end of the second inductor, and the other end of the second inductor and the common terminal of the output voltage detection terminal of the buck regulator chip are connected separately. The third resistor and the fourth capacitor are connected to the power supply voltage terminals of the rear and front main control chips, respectively. One end of the third resistor and one end of the fourth capacitor are connected to the common terminal of the other end of the second inductor and the output voltage detection terminal of the buck regulator chip. The other end of the third resistor and the other end of the fourth capacitor are connected to the configuration terminal of the buck regulator chip. The second resistor is connected to the common terminal of the third resistor and the fourth capacitor, and the other end of the second resistor is grounded. One end of the fifth capacitor and one end of the sixth capacitor are connected to the common terminal of the rear main control chip, the power supply voltage terminal of the front main control chip, and the second inductor, respectively. The other ends of the fifth capacitor, the sixth capacitor, and the seventh capacitor are grounded.

[0023] In a further embodiment of this invention, the front clock circuit includes a first crystal oscillator, a seventh capacitor, and an eighth capacitor. One end of the first crystal oscillator is connected to the crystal input terminal of the front main control chip, and the other end of the first crystal oscillator is connected to the crystal output terminal of the front main control chip. One end of the seventh capacitor is connected to the common terminal of the crystal oscillator and the crystal output terminal of the front main control chip. One end of the eighth capacitor is connected to the common terminal of the crystal oscillator and the crystal input terminal of the front main control chip. The other ends of the seventh capacitor and the other ends of the eighth capacitor are respectively grounded.

[0024] The post-clock circuit includes a second crystal oscillator; one end of the second crystal oscillator is connected to the crystal input terminal of the post-master control chip, and the other end of the second crystal oscillator is connected to the crystal output terminal of the post-master control chip; the second crystal oscillator is used as the system crystal frequency.

[0025] Secondly, this utility model also provides a smart door lock, comprising: a front lock housing with a handle, a rear lock housing with a handle, and the aforementioned fingerprint recognition-based smart door lock control circuit. The front lock housing with a handle and the rear lock housing with a handle are disposed opposite to each other. The fingerprint recognition-based smart door lock control circuit is disposed in the internal space between the front lock housing with a handle and the rear lock housing with a handle. The front fingerprint module of the fingerprint recognition-based smart door lock control circuit is disposed on the handle of the front lock housing, and the rear fingerprint module of the fingerprint recognition-based smart door lock control circuit is disposed on the handle of the rear lock housing.

[0026] This utility model provides a fingerprint recognition-based smart door lock control circuit and a smart door lock. The fingerprint recognition-based smart door lock control circuit includes: a front locking assembly, a rear locking assembly, and a lock body. The front locking assembly includes: a front fingerprint module, a front lock mainboard module, and a front clutch motor. The rear locking assembly includes: a rear fingerprint module, a rear lock mainboard module, and a rear clutch motor. The front fingerprint module is used to set the recorded fingerprint information as the front unlocking fingerprint information and to output a matching control signal when the collected current fingerprint information matches the front unlocking fingerprint information. The rear fingerprint module is used to set the recorded fingerprint information as the rear unlocking fingerprint information and to output a matching control signal when the collected current fingerprint information matches the rear unlocking fingerprint information. The front lock mainboard module is connected to both the front fingerprint module and the rear fingerprint module. The system is configured to: output a front clutch control signal to control the working state of the front clutch motor when receiving a matching control signal from the front fingerprint module; and output a rear lock unlocking signal when receiving a matching control signal from the rear fingerprint module. The front clutch motor is connected to both the front lock main board module and the lock body, and is used to receive the front clutch control signal and drive the lock body to unlock. The rear lock main board module is connected to the front lock main board module, and is used to send or receive unlocking fingerprint information to the front lock main board module via a serial port, and to output a rear clutch control signal when receiving a rear lock unlocking signal from the front lock main board module. The rear clutch motor is connected to both the rear lock main board module and the lock body, and is used to receive the rear clutch control signal and drive the lock body to unlock. This invention provides a fingerprint-based smart door lock control circuit that, by setting fingerprint modules on the front and rear lock components respectively, controls the clutch motors on both sides of the front and rear locks, achieving dual-sided security protection for entry and exit. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a structural block diagram of a fingerprint-based smart door lock control circuit in a preferred embodiment of this utility model.

[0029] Figure 2 This is a structural block diagram of a fingerprint-based smart door lock control circuit in a further embodiment of a preferred embodiment of this utility model.

[0030] Figure 3This is a circuit diagram of the voltage regulator circuit in a preferred embodiment of this utility model.

[0031] Figure 4 This is a circuit diagram of the back clock circuit in a preferred embodiment of this utility model.

[0032] Figure 5 This is a circuit diagram of the front main control chip and the front clock circuit in a preferred embodiment of this utility model.

[0033] Figure 6 This is a circuit diagram of the main control chip in a preferred embodiment of this utility model.

[0034] Figure 7 This is a circuit diagram of the front clutch motor drive circuit or the rear clutch motor drive circuit in a preferred embodiment of this utility model.

[0035] The markings in the attached diagram are as follows: 1. Front lock assembly; 11. Front fingerprint module; 12. Front lock main board module; 121. Front voltage regulator circuit; 122. Front main control chip circuit; 123. Front clock circuit; 124. Front clutch motor drive circuit; 13. Front clutch motor; 2. Rear lock assembly; 21. Rear fingerprint module; 22. Rear lock main board module; 221. Rear voltage regulator circuit; 222. Rear main control chip circuit; 223. Rear clock circuit; 224. Rear clutch motor drive circuit; 23. Rear clutch motor; 3. Lock body. Detailed Implementation

[0036] This utility model provides a fingerprint recognition-based smart door lock control circuit and a smart door lock. To make the purpose, technical solution, and effects of this utility model clearer and more explicit, the following describes this utility model in further detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit this utility model.

[0037] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of this utility model involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0038] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0039] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0040] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0041] The applicant's research revealed that existing smart lock products primarily target the entryway market, featuring identity verification via a key on one side and a less secure mechanical or sensor switch on the other. This allows for control over individuals entering private spaces from public areas, while facilitating exiting without a key, relying solely on the mechanical or sensor switch. However, in scenarios requiring higher security, the mechanical or sensor switch side is vulnerable to manipulation, allowing objects to be inserted through door gaps, compromising security. In certain high-security situations, smart locks with only one-way identity verification present certain security risks. Furthermore, the internal structure of mechanical or sensor switches is prone to wear and deformation, resulting in a shorter lifespan compared to fingerprint-based electronic locks. Damage to these switches necessitates complete replacement, incurring maintenance costs.

[0042] like Figure 1As shown, to address the aforementioned technical problems, this utility model provides a smart door lock control circuit based on fingerprint recognition, comprising a front locking assembly 1, a rear locking assembly 2, and a lock body 3. The front locking assembly 1 includes a front fingerprint module 11, a front lock mainboard module 12, and a front clutch motor 13. The rear locking assembly 2 includes a rear fingerprint module 21, a rear lock mainboard module 22, and a rear clutch motor 23. The front fingerprint module 11 is used to set the recorded fingerprint information as the front unlocking fingerprint information and to output a matching control signal when the collected current fingerprint information matches the front unlocking fingerprint information. The rear fingerprint module 21 is used to set the recorded fingerprint information as the rear unlocking fingerprint information and to output a matching control signal when the collected current fingerprint information matches the rear unlocking fingerprint information. The front lock mainboard module 12 is connected to both the front fingerprint module 11 and the rear fingerprint module 21, and... The system outputs a front clutch control signal to control the working state of the front clutch motor 13 when receiving a matching control signal from the front fingerprint module 11; and outputs a rear lock unlocking signal when receiving a matching control signal from the rear fingerprint module 21. The front clutch motor 13 is connected to the front lock main board module 12 and the lock body 3 respectively, and is used to receive the front clutch control signal and drive the lock body 3 to unlock. The rear lock main board module 22 is connected to the front lock main board module 12, and is used to send or receive unlocking fingerprint information to the front lock main board module 12 via a serial port, and is used to output a rear clutch control signal when the rear lock unlocking signal output by the front lock main board module 12 is collected. The rear clutch motor 23 is connected to the rear lock main board module 22 and the lock body 3 respectively, and is used to receive the rear clutch control signal and drive the lock body 3 to unlock.

[0043] The basic working principle of a smart door lock based on fingerprint biometric technology includes fingerprint enrollment and fingerprint unlocking. For fingerprint enrollment, the mainboard module in the smart door lock has a control center; for example, this control center can be any type of main control chip. The corresponding mainboard module first sends a fingerprint acquisition command to the fingerprint module via a serial port. The fingerprint module acquires the user's fingerprint and processes it using an algorithm, converting the fingerprint into feature data for storage. Each time the user enrolls a fingerprint, one piece of feature data is stored; this feature data is either the front lock unlocking fingerprint information or the rear lock unlocking fingerprint information. Simultaneously, the corresponding fingerprint module outputs unlocking fingerprint information to the front lock mainboard module 12, which then transmits the unlocking fingerprint information to the fingerprint module in the opposite door lock assembly. That is, the front unlocking fingerprint information entered by the user in the front fingerprint module 11 is sent from the front lock motherboard module 12 to the rear fingerprint module 21, and the rear unlocking fingerprint information entered by the user in the rear fingerprint module 21 is sent from the front lock motherboard module 12 to the front fingerprint module 11. This realizes the synchronization of fingerprint biometric information between the two fingerprint modules of the front lock component 1 and the rear lock component 2, simplifies the fingerprint enrollment process, and improves the efficiency of fingerprint information registration and enrollment.

[0044] For fingerprint unlocking, the main board module of the corresponding side lock first sends a fingerprint acquisition command via serial port. The fingerprint module acquires the fingerprint and processes it using an algorithm to convert the user's fingerprint into feature data. This feature data is then compared with stored feature data. When the similarity between this feature data and the feature data stored in the fingerprint module reaches a threshold, the verification is successful, and a fingerprint verification success signal is returned to the control unit in the front lock main board module 12. The fingerprint verification success signal is the matching control signal. After receiving this signal, the front lock main board module 12 considers the fingerprint to be legitimate. When the matching control signal is sent by the front fingerprint module 11, the front lock main board module 12 sends a front clutch control signal to the front clutch motor drive circuit 124. The front clutch motor drive circuit 124 drives the front clutch motor 13 to work. The lock cylinder of the smart lock disengages the front clutch reversing clip through the clutch motor, allowing the user to manually unlock from the front lock side. Accordingly, to further simplify the circuit, when the matching control signal is sent by the rear fingerprint module 21, the front lock main board module 12 uniformly implements fingerprint information acquisition interrupt control and power enable control. That is, the front lock main board module 12 manages the fingerprint recognition modules on both the front and rear sides. When the rear fingerprint module 21 sends the matching control signal, the front lock main board module 12 sends a rear clutch control signal to the rear lock main board module 22, and the rear lock main board module 22 controls the rear clutch motor drive circuit 224 to drive the rear clutch motor 23 to work, allowing the user to manually unlock from the rear lock side. It should be noted that the user can only open the smart lock from that side when fingerprint recognition is completed and the clutch motor is in working condition, to prevent the smart lock from being unlocked on one side and then attempting to open from the other side, further improving the security of the smart lock.

[0045] Furthermore, the front lock mainboard module 12 includes: a front main control chip circuit 122, a front clock circuit 123, and a front clutch motor drive circuit 124; wherein, the front main control chip circuit 122 is connected to the rear fingerprint module 21 and is used to output rear unlocking fingerprint information from the rear fingerprint module 21 to the front fingerprint module 11, or receive and output front unlocking fingerprint information from the front fingerprint module 11 to the rear fingerprint module 21; or receive matching control signals from the front fingerprint module 11 or the rear fingerprint module 21: when the matching... The matching control signal comes from the front fingerprint module 11, and the front main control chip circuit 122 outputs the front clutch motor 13 drive signal; when the matching control signal comes from the rear fingerprint module 21, the front main control chip circuit 122 outputs the rear lock unlock signal; the front clock circuit 123 is connected to the front main control chip circuit 122 to provide clock synchronization information; the front clutch motor drive circuit 124 is connected to the front main control chip circuit 122 to drive the front clutch motor 13 to work according to the front clutch motor 13 drive signal.

[0046] Specifically, the connection diagram of the front main control chip circuit 122 is as follows: Figure 6 As shown, the front main control chip U2B is an integrated circuit chip CY8C6245AZI-83D42 that supports Bluetooth Low Energy (BLE) connectivity. The serial port transmit pin FR_COM_TXD, serial port receive pin FR_COM_RXD, and low-power wake-up pin REAR_WAKE of the front main control chip U2B are respectively connected to the serial port pins of the rear main control chip circuit 222, and communicate with the rear main control chip circuit 222 via these pins. The front main control chip U2B uniformly controls the fingerprint information input and detection of the front fingerprint module 11 and the rear fingerprint module 21, and is used to implement fingerprint information acquisition interruption and power enable control. It should be noted that the specific implementation of the fingerprint information acquisition interruption and power enable control is a conventional technique in this field and will not be elaborated upon here.

[0047] Furthermore, such as Figure 4 As shown, the front clock circuit 123 includes a first crystal oscillator Y1, a seventh capacitor C7, and an eighth capacitor C8. One end of the first crystal oscillator Y1 is connected to the crystal input terminal of the front main control chip U2B, and the other end of the first crystal oscillator Y1 is connected to the crystal output terminal of the front main control chip U2B. One end of the seventh capacitor C7 is connected to the common terminal of the crystal oscillator and the crystal output terminal of the front main control chip U2B. One end of the eighth capacitor C8 is connected to the common terminal of the crystal oscillator and the crystal input terminal of the front main control chip U2B. The other ends of the seventh capacitor C7 and the eighth capacitor C8 are grounded respectively. The seventh capacitor C7 and the eighth capacitor C8 are matching capacitors used to match the crystal oscillator and the oscillation circuit, making the front clock circuit 123 easy to start oscillating and in a reasonable excitation state. The oscillation frequency of the first crystal oscillator is 32.768KHz, which is used as an external timer for the front main control chip U2B to provide reference frequency information.

[0048] Furthermore, the rear lock motherboard module 22 includes: a rear main control chip circuit 222, a rear clock circuit 223, and a rear clutch motor drive circuit 224; wherein, the rear main control chip circuit 222 is connected to the front main control chip circuit 122, and is used to receive the rear lock unlocking signal from the front main control chip circuit 122 and output the rear clutch motor 23 drive signal; the rear clock circuit 223 is connected to the rear main control chip circuit 222, and is used to provide clock synchronization information to the rear main control chip circuit 222; the rear clutch motor drive circuit 224 is connected to the rear main control chip circuit 222, and is used to drive the rear clutch motor 23 to work according to the rear clutch motor 23 drive signal.

[0049] Specifically, please refer to the following: Figure 5 The rear master control chip circuit 222 includes a rear master control chip U2. The power supply terminal of the rear master control chip U2 is connected to one end of the third inductor L3, and the other end of the third inductor L3 is connected to a 3.3V operating voltage. One end of the ninth capacitor C9 and one end of the tenth capacitor C10 are respectively connected to the third inductor L3 and the power supply terminal of the rear master control chip U2. The other end of the ninth capacitor C9 is grounded to filter out high-frequency interference from external radiation and pulse interference generated by the rear master control chip U2 itself during operation, thereby reducing power supply pulse jitter. The rear master control chip U2 is connected to the rear clock circuit 223. The rear main control chip U2 is preferably an OM6621PG dual-mode wireless connection chip with a low-power full-function Bluetooth 5.1 protocol stack and a 2.4GHz proprietary protocol. It meets the low-power Bluetooth data transmission rate and distance requirements of this application. When the front fingerprint module 11 outputs a matching control signal, the rear main control chip U2 receives a signal from the front main control chip U2B via serial communication. This signal from the front main control chip U2B is an arbitrary unlocking command signal, which controls the rear clutch motor drive circuit 224 to drive the rear clutch motor 23 to disengage the reversing bolt of the lock body 3. The method of driving the rear clutch motor 23 via the rear clutch motor drive circuit 224 is the same as that of driving the front clutch motor 13 via the front main control chip U2B, and will not be described again here. With the rear clutch motor 23 operating, the reversing bolt between the rear and the lock body 3 is disengaged, allowing the user to open the door by turning the handle from one side of the rear lock assembly 2.

[0050] The rear clock circuit 223 is an external timer for the rear main control chip U2, used to ensure the integrity of data reception during communication between the rear main control chip U2 and the front fingerprint module 11 and the rear lock motherboard module 22. The rear clock circuit 223 includes a second crystal oscillator Y2; one end of the second crystal oscillator Y2 is connected to the crystal oscillator input terminal of the rear main control chip U2, and the other end is connected to the crystal oscillator output terminal of the rear main control chip U2; the second crystal oscillator Y2 serves as the system crystal oscillator frequency. The second crystal oscillator Y2 provides a 32MHz front clock frequency signal to the rear main control chip U2, which uses this front clock frequency signal to transmit and receive data and determine whether data reception is complete.

[0051] Furthermore, in a preferred embodiment of this application, the fingerprint-based smart door lock control circuit further includes a voltage regulator circuit. This voltage regulator circuit is connected to an external power supply voltage and is connected to the power supply voltage terminals of the front main control chip U2B and the rear main control chip U2, respectively. It is used to step down and regulate the power supply voltage to a working voltage, which is used to power the front main control chip U2B and the rear main control chip U2, respectively. The voltage regulator circuit steps down and regulates the 6V external power supply voltage to 3.3V, which is then used as the working voltage to power the front main control chip U2B or the rear main control chip U2. The voltage regulator circuit can be located on the main board of the front lock assembly 1 or on the main board of the rear lock assembly 2. The external power supply voltage can be provided by any type of external power supply, and the battery can be a lead-acid battery, lithium battery, alkaline battery, carbon battery, or other power source that can be used to provide the power supply voltage.

[0052] In another preferred embodiment of this utility model, such as Figure 2 As shown, to achieve a detachable connection between the front locking assembly 1, the rear locking assembly 2, and the lock body 3, the front locking main board module 12 further includes a front voltage regulator circuit 121, and the rear locking main board module 22 further includes a rear voltage regulator circuit 221. The front voltage regulator circuit 121 and the rear voltage regulator circuit 221 are respectively connected to an external power supply. The front voltage regulator circuit 121 is used to step down and regulate the power supply voltage to the front locking operating voltage, which powers the front main control chip U2B. The rear voltage regulator circuit 221 is used to step down and regulate the power supply voltage to the rear locking operating voltage, which powers the rear main control chip U2B. When the fingerprint-based smart door lock control circuit is working, the front main control chip circuit 122 is supplied with its operating voltage by the front voltage regulator circuit 121, which is also located on the main board of the front locking assembly 1, and the rear main control chip circuit 222 is supplied with its operating voltage by the rear voltage regulator circuit 221, which is also located on the main board of the rear locking assembly 2, facilitating installation and maintenance during actual use.

[0053] Furthermore, please refer to the following: Figure 3The voltage regulator circuit includes: a first inductor L1, a second inductor L2, a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a buck regulator chip U1; wherein, one end of the first inductor L1 is connected to the power supply voltage, and the other end of the first inductor L1 is connected to the power supply terminal and the enable terminal of the buck regulator chip U1, respectively; one end of the first capacitor C1, one end of the second capacitor C2, and one end of the third capacitor C3 are respectively connected to the power supply terminal of the buck regulator chip U1, and the other ends of the first capacitor C1, the second capacitor C2, and the third capacitor C3 are grounded; the mode selection terminal of the buck regulator chip U1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is grounded, and the ground terminal of the buck regulator chip U1 is grounded; the switching control terminal of the buck regulator chip U1 is connected to the first resistor R1, the second resistor R2, the third resistor R3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, and the sixth capacitor C6. One end of the second inductor L2 is connected, and the other end of the second inductor L2 and the common terminal of the output voltage detection terminal of the buck regulator chip U1 are respectively connected to the power supply voltage terminal of the front main control chip U2B and the power supply voltage terminal of the rear main control chip U2. One end of the third resistor R3 and one end of the fourth capacitor C4 are respectively connected to the other end of the second inductor L2 and the common terminal of the output voltage detection terminal of the buck regulator chip U1. The other end of the third resistor R3 and the other end of the fourth capacitor C4 are connected to the configuration terminal of the buck regulator chip U1. The second resistor R2 is connected to the common terminal of the third resistor R3 and the fourth capacitor C4, and the other end of the second resistor R2 is grounded. One end of the fifth capacitor C5 and one end of the sixth capacitor C6 are respectively connected to the power supply voltage terminal of the front main control chip U2B, the power supply voltage terminal of the rear main control chip U2 and the common terminal of the second inductor L2. The other ends of the fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor C7 are grounded. The step-down regulator chip U1, model TPS629210, has a synchronous step-down DC / DC conversion function. It converts the external 6V power supply voltage to a 3.3V operating voltage to power either the front main control chip circuit 122 or the rear main control chip circuit 222. The operating voltage output by the regulator circuit is related to the ratio of the second resistor R2 to the third resistor R3. Specifically, the resistance of the second resistor R2 is 137KΩ, and the resistance of the third resistor R3 is 619KΩ.

[0054] Please refer to the following: Figure 2 and Figure 7The front clutch motor drive circuit 124 is connected to the front main control chip circuit 122, and the rear clutch motor drive circuit 224 is connected to the rear main control chip circuit 222. The front clutch motor drive circuit 124 controls the front clutch motor 13, and the rear clutch motor drive circuit 224 controls the rear clutch motor 23. In this application, the front clutch motor drive circuit 124 is used as an example to describe the clutch motor drive circuit.

[0055] The front clutch motor drive circuit 124 includes: a motor drive chip U3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a deadbolt inductor, a fifth inductor L5, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, and a sixteenth capacitor C16; wherein, one end of the fourth resistor R4 is connected to the first motor control terminal of the front main control chip circuit 122, and the other end of the fourth resistor R4 is connected to the first input terminal of the motor drive chip U3; one end of the fifth resistor R5 is connected to the second motor control terminal of the front main control chip U2B, and the other end of the fifth resistor R5 is connected to the second input terminal of the motor control chip; one end of the sixth resistor R6 is connected to the low-power wake-up terminal of the front main control chip U2B, and the other end of the sixth resistor R6 is connected to the state enable terminal of the motor drive chip U3; the power supply voltage terminal of the motor drive chip U3 is connected to the operating voltage; one end of the eleventh capacitor C11 is connected to one end of the motor drive chip U3; and the... The other end of the eleventh capacitor C11 and the grounding terminal of the motor drive chip U3 are respectively grounded; the first output terminal of the motor drive chip U3 is connected to one end of the fourth inductor L4, and the other end of the fourth inductor L4 is connected to the first control terminal of the motor; the second output terminal of the motor drive circuit is connected to one end of the fifth inductor L5, and the other end of the fifth inductor L5 is connected to the second control terminal of the motor; one end of the fifteenth capacitor C15 is connected to the common terminal of the fifth inductor L5 and the motor, one end of the sixteenth capacitor C16 is connected to the common terminal of the fourth inductor L4 and the motor, and the other ends of the fifteenth capacitor C15 and the sixteenth capacitor C16 are grounded; the motor voltage terminal of the motor drive chip U3 is connected to the power supply voltage, one end of the twelfth capacitor C12, one end of the thirteenth capacitor C13 and one end of the fourteenth capacitor C14 are respectively connected to the motor voltage terminal of the motor drive chip U3, and the other ends of the twelfth capacitor C12, the thirteenth capacitor C13 and the fourteenth capacitor C14 are respectively grounded. Preferably, the motor drive chip U3 is a low-voltage DC motor drive IC chip, and the model of the motor drive chip U3 is TMI8837. When the front main control chip U2B receives the matching control signal and the matching control signal is output from the front fingerprint module 11, the first motor control terminal and the second motor control terminal of the front main control chip U2B output two front clutch control signals. The first input terminal and the second input terminal of the motor drive chip U3 receive the front clutch control signal and output a control signal for driving the front clutch motor 13. The control signal can be a PWM control signal, or it can be replaced by a vector control or square wave control signal, etc., to realize the conversion from the matching control signal to the clutch motor control signal, so as to realize the opening of the corresponding smart door lock.The rear clutch motor drive circuit 224 in the rear lock structure has the same circuit diagram as the front clutch motor drive circuit 124, and will not be described again here.

[0056] This application utilizes electronic and structural embedded development methods to achieve the integration, embedded hardware layout, and electronic circuit design of a dual-fingerprint module and electronic control circuit in a fingerprint-based smart door lock control circuit. When a user approaches and activates the corresponding component of the smart door lock (which may be the front locking component 1 or the rear locking component 2), the user enters management mode. In management mode, the user completes fingerprint biometric information collection. When the user completes information collection in the front locking component 1, the fingerprint biometric information is recorded as the front unlock fingerprint information; when the user completes information collection in the rear locking component 2, the fingerprint biometric information is recorded as the rear unlock fingerprint information. The front or rear unlock fingerprint information is synchronized between the two fingerprint modules and stored. If the front unlock fingerprint information in the front fingerprint module 11 and the rear unlock fingerprint information in the rear fingerprint module 21 are consistent, fingerprint registration is successful, and the user can exit management mode. When the smart lock is working normally, the user approaches the lock body 3 and unlocks it with the registered fingerprint recognition. The smart lock's control system determines the location of the corresponding fingerprint module and drives the corresponding clutch motor to achieve reversing and disengagement, thus ensuring manual unlocking.

[0057] The working principle and application process of fingerprint recognition-based smart door lock control circuit are as follows:

[0058] When the smart lock is in standby mode: In the front lock assembly 1, the battery supplies power to the power and enable terminals of the step-down regulator chip U1 in the front voltage regulator circuit 121, i.e., pin 6 VIN and pin 7 EN. After step-down regulation, a +3V3 operating voltage is output from the output voltage detection terminal and switch control terminal of the front voltage regulator circuit 121, i.e., pin 3 VOS and pin 4 SW, to power the front main control chip circuit 122. The front clock circuit 123 provides clock synchronization information to the crystal oscillator output and crystal oscillator input terminals of the front main control chip U2B, i.e., pin 7 RTC_XO and pin 8 RTC_XI of the front main control chip U2B. The front main control chip U2B completes fingerprint information acquisition interrupt and power enable control with the front fingerprint module 11 through pin 28 FP_TP_INT and pin 25 FP_PWR_EN. The front main control chip U2B of the front lock assembly 1 is connected to the rear fingerprint module 21 through pin 39 FP_TP_INT and pin 95 FP_PWR_EN, and is used to realize fingerprint information acquisition interruption and power enable control.

[0059] In the rear lock assembly 2, the battery supplies power to the power and enable terminals of the rear voltage regulator circuit 221, namely pin 6 (VIN) and pin 7 (EN). After being stepped down and regulated, the power supply voltage outputs a +3V3 operating voltage from the output voltage detection terminal and switch control terminal of the step-down regulator chip in the rear voltage regulator circuit 221, namely pin 3 (VOS) and pin 4 (SW), to power the rear main control chip U2. The crystal in the rear clock circuit 223 provides reference frequency information to pin 14 (XTAL32M_N) and pin 15 (XTAL32M_P) of the rear main control chip U2.

[0060] When the smart lock is in fingerprint registration mode: Fingerprints are registered in the front locking component 1. The front fingerprint module 11 collects the fingerprint biometric information and records it as the front unlocking fingerprint information. Information synchronization is achieved through pins 3 (FP_TXD) and 2 (FP_RXD) of the front fingerprint module 11 with pins 23 (FP_RXD) and 24 (FP_TXD) of the front main control chip U2B. Similarly, when fingerprints are registered in the rear locking component 2, the rear fingerprint module 21 collects the fingerprint biometric information and records it as the rear unlocking fingerprint information. Information synchronization is achieved through pins 3 (FP_TXD) and 2 (FP_RXD) of the rear fingerprint module 21 with pins 36 (FP_REAR_RXD) and 37 (FP_REAR_TXD) of the main control chip.

[0061] When the smart door lock is in fingerprint recognition unlocking mode: When a fingerprint is registered in the front lock component 1, the front fingerprint module 11 collects the fingerprint biometric information and compares it with the registered front unlocking fingerprint information. If the comparison is successful, the front fingerprint module 11 sends a matching control signal to pin 23 FP_RXD and pin 24 FP_TXD of the front main control chip U2B to complete the information input. After processing by the front main control chip U2B, the front main control chip U2B outputs a front clutch control signal to control the working state of the front clutch motor 13 through pin 26 MOTO_IN1, pin 27 MOTO_IN2, and pin 44 M_nSLEEP. The motor drive chip U3 receives the front clutch control signal to control the working state of the front clutch motor 13, thereby driving the front clutch motor 13 to realize the unlocking function of the front lock body 3. A fingerprint is entered into the rear lock assembly 2. The rear fingerprint module 21 receives the fingerprint biometric information and compares it with the entered rear unlock fingerprint information. If the comparison is successful, the rear fingerprint module 21 sends matching control signals to the front main control chip U2B via pin 3 FP_REAR_RXD and pin 2 FP_REAR_TXD, respectively, to complete the information input. The front master control chip U2B detects the matching control signal and outputs an unlocking command to the rear master control chip U2. The data transmission is performed through pins 35 (FR_COM_TXD), 34 (FR_COM_RXD), and 12 (REAR_WAKE) of the front master control chip U2B, which are connected to pins 43 (FR_COM_TXD), 44 (FR_COM_RXD), and 42 (REAR_WAKE) of the rear master control chip U2, respectively. The rear master control chip U2 outputs the rear clutch control signal from pins 34 (MOTO_IN1), 33 (MOTO_IN2), and 35 (M_nSLEEP). Pins 6 (IN1), 5 (IN2), and 7 (nSLEEP) of the motor drive chip U3 in the rear clutch motor drive circuit 224 detect the rear clutch control signal and drive the rear clutch motor 23 to realize the unlocking function of the rear lock body 3.

[0062] On the other hand, this utility model also provides a smart door lock, which includes: a front lock housing with a handle, a rear lock housing with a handle, and the aforementioned fingerprint recognition-based smart door lock control circuit. The front lock housing with a handle and the rear lock housing with a handle are disposed opposite to each other. The fingerprint recognition-based smart door lock control circuit is disposed in the internal space between the front lock housing with a handle and the rear lock housing with a handle. The front fingerprint module of the fingerprint recognition-based smart door lock control circuit is disposed on the handle of the front lock housing, and the rear fingerprint module of the fingerprint recognition-based smart door lock control circuit is disposed on the handle of the rear lock housing.

[0063] In summary, this application provides a fingerprint recognition-based smart door lock control circuit and a smart door lock, which have the following beneficial effects:

[0064] The fingerprint recognition-based smart door lock control circuit provided by this utility model has fingerprint modules set on the front lock assembly and the rear lock assembly respectively, which control the clutch motors on both sides of the front lock and the rear lock respectively. Only the side that has passed the recognition can turn the door lock to open the door, realizing dual-sided security protection for entry and exit, and effectively improving the security of the fingerprint recognition-based smart door lock.

[0065] In this invention, the front and rear locking components of the smart door lock are electronic door locks with fingerprint recognition function, which have a slower wear rate, longer service life, and are easier to maintain compared to mechanical door locks.

[0066] It should be understood that the application of this utility model is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A smart door lock control circuit based on fingerprint recognition, characterized in that, It includes a front locking assembly, a rear locking assembly, and a lock body: the front locking assembly includes a front fingerprint module, a front lock mainboard module, and a front clutch motor; the rear locking assembly includes a rear fingerprint module, a rear lock mainboard module, and a rear clutch motor; wherein, The front fingerprint module is used to set the recorded fingerprint information as the front unlocking fingerprint information, and to output a matching control signal when the collected current fingerprint information matches the front unlocking fingerprint information. The rear fingerprint module is used to set the recorded fingerprint information as the rear unlocking fingerprint information, and to output a matching control signal when the collected current fingerprint information matches the rear unlocking fingerprint information. The front lock mainboard module is connected to the front fingerprint module and the rear fingerprint module respectively. It is used to output a front clutch control signal to control the working state of the front clutch motor when receiving the matching control signal output by the front fingerprint module; and to output a rear lock unlocking signal when receiving the matching control signal output by the rear fingerprint module. The front clutch motor is connected to the front lock main board module and the lock body respectively, and is used to receive the front clutch control signal and drive the lock body to unlock; The rear lock motherboard module is connected to the front lock motherboard module and is used to send or receive unlocking fingerprint information to the front lock motherboard module via a serial port, and to output a rear clutch control signal when receiving the rear lock unlocking signal output by the front lock motherboard module. The rear clutch motor is connected to the rear lock main board module and the lock body respectively, and is used to receive the rear clutch control signal and drive the lock body to unlock.

2. The smart door lock control circuit based on fingerprint recognition according to claim 1, characterized in that, The front locking motherboard module includes: a front main control chip, a front clock circuit, and a front clutch motor drive circuit; wherein... The front main control chip is connected to the front fingerprint module and is used to output rear unlocking fingerprint information from the rear fingerprint module to the front fingerprint module, or to receive and output front unlocking fingerprint information from the front fingerprint module to the rear fingerprint module; or to receive matching control signals from the front fingerprint module or the rear fingerprint module: when the matching control signal comes from the front fingerprint module, the front main control chip outputs a front clutch motor drive signal; when the matching control signal comes from the rear fingerprint module, the front main control chip outputs a rear lock unlocking signal; The front clock circuit is connected to the front main control chip and is used to provide clock synchronization information; The front clutch motor drive circuit is connected to the front main control chip and is used to drive the front clutch motor to work according to the front clutch motor drive signal.

3. The smart door lock control circuit based on fingerprint recognition according to claim 2, characterized in that, The rear locking motherboard module includes: a rear main control chip, a rear clock circuit, and a rear clutch motor drive circuit; wherein... The rear main control chip is connected to the front main control chip and is used to receive the rear lock unlocking signal from the front main control chip and output the rear clutch motor drive signal. The rear clock circuit is connected to the rear main control chip and is used to provide clock synchronization information to the rear main control chip; The rear clutch motor drive circuit is connected to the rear main control chip and is used to drive the rear clutch motor to work according to the rear clutch motor drive signal.

4. The fingerprint recognition-based smart door lock control circuit according to claim 3, characterized in that, It also includes a voltage regulator circuit, which is connected to an external power supply voltage and is connected to the power supply voltage terminals of the front main control chip and the rear main control chip, respectively, to step down and regulate the power supply voltage to the operating voltage, which is used to power the front main control chip and the rear main control chip, respectively.

5. The smart door lock control circuit based on fingerprint recognition according to claim 3, characterized in that, The front lock motherboard module further includes a front voltage regulator circuit, and the rear lock motherboard module further includes a rear voltage regulator circuit. The front and rear voltage regulator circuits are respectively connected to an external power supply voltage. The front voltage regulator circuit is used to step down and regulate the power supply voltage to the front lock operating voltage, which is used to power the front main control chip. The rear voltage regulator circuit is used to step down and regulate the power supply voltage to the rear lock operating voltage, which is used to power the rear main control chip.

6. The smart door lock control circuit based on fingerprint recognition according to claim 4, characterized in that, The voltage regulator circuit includes: a first inductor, a second inductor, a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, and a buck regulator chip; wherein, One end of the first inductor is connected to the power supply voltage, and the other end of the first inductor is connected to the power supply terminal and the enable terminal of the buck regulator chip, respectively. One end of the first capacitor, one end of the second capacitor, and one end of the third capacitor are connected to the power supply terminal of the buck regulator chip, and the other ends of the first capacitor, the second capacitor, and the third capacitor are grounded. The mode selection terminal of the buck regulator chip is connected to one end of the first resistor, the other end of the first resistor is grounded, and the ground terminal of the buck regulator chip is grounded. The switch control terminal of the buck regulator chip is connected to one end of the second inductor, and the other end of the second inductor and the common terminal of the output voltage detection terminal of the buck regulator chip are connected separately. The third resistor and the fourth capacitor are connected to the power supply voltage terminals of the rear and front main control chips, respectively. One end of the third resistor and one end of the fourth capacitor are connected to the common terminal of the other end of the second inductor and the output voltage detection terminal of the buck regulator chip. The other end of the third resistor and the other end of the fourth capacitor are connected to the configuration terminal of the buck regulator chip. The second resistor is connected to the common terminal of the third resistor and the fourth capacitor, and the other end of the second resistor is grounded. One end of the fifth capacitor and one end of the sixth capacitor are connected to the common terminal of the rear main control chip, the power supply voltage terminal of the front main control chip, and the second inductor, respectively. The other ends of the fifth capacitor, the sixth capacitor, and the seventh capacitor are grounded.

7. The smart door lock control circuit based on fingerprint recognition according to claim 4, characterized in that, The front clock circuit includes a first crystal oscillator, a seventh capacitor, and an eighth capacitor. One end of the first crystal oscillator is connected to the crystal input terminal of the front main control chip, and the other end of the first crystal oscillator is connected to the crystal output terminal of the front main control chip. One end of the seventh capacitor is connected to the common terminal of the crystal oscillator and the crystal output terminal of the front main control chip. One end of the eighth capacitor is connected to the common terminal of the crystal oscillator and the crystal input terminal of the front main control chip. The other ends of the seventh capacitor and the other ends of the eighth capacitor are respectively grounded. The post-clock circuit includes a second crystal oscillator; one end of the second crystal oscillator is connected to the crystal input terminal of the post-master control chip, and the other end of the second crystal oscillator is connected to the crystal output terminal of the post-master control chip; the second crystal oscillator is used as the system crystal frequency.

8. A smart door lock, characterized in that, include: The system comprises a front lock housing with a handle, a rear lock housing with a handle, and a fingerprint-based smart lock control circuit as described in any one of claims 1-7. The front lock housing with a handle and the rear lock housing with a handle are disposed opposite to each other. The fingerprint-based smart lock control circuit is disposed in the internal space between the front lock housing with a handle and the rear lock housing with a handle. The front fingerprint module of the fingerprint-based smart lock control circuit is disposed on the handle of the front lock housing, and the rear fingerprint module of the fingerprint-based smart lock control circuit is disposed on the handle of the rear lock housing.

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