Energy Transmission and Signal Transmission Method for a Passive Wireless Lock

Abstract

The present invention provides a method for energy transmission and signal transmission of a passive wireless lock. By transmitting energy in the form of intermittent pulses, this design not only realizes the power supply function, but also realizes signal transmission through the timing coding of the pulses. Through this pulse coding mechanism, energy transmission and signal transmission no longer require independent hardware modules, which not only simplifies the system design but also improves the transmission efficiency. It includes the following steps: S1: Use pulse-type energy transmission and time coding mechanism for signal transmission; S2: Set the synchronization and decoding mechanism for signal transmission; S3: Integrate the design of energy transmission and signal transmission; S4: Improve the anti-interference ability during the transmission process; S5: Improve system security.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless locks, and particularly to an energy transmission and signal transmission method for a passive wireless lock. In particular, it is directed to an energy transmission and signal transmission method in the field of anti-theft for commodity display. This method realizes power supply and data communication for the passive lock wirelessly, and is applicable to systems such as anti-theft display cabinets and intelligent door locks Background Art

[0002] In the fields of anti-theft for commodity display, intelligent door locks, etc., passive locks, as a type of lock without an internal power supply, have been widely used due to their advantages such as simple structure, convenient use, and low cost. Passive locks usually rely on external devices (such as keys, controllers) for power supply and unlocking, and are mainly applied to scenarios that require low power consumption, high stability, and low maintenance costs, such as anti-theft display cabinets, intelligent access control systems, and safes

[0003] In the prior art, the energy transmission and signal transmission schemes for passive locks are mainly divided into two categories: contact transmission and wireless transmission

[0004] 1. Contact Energy and Signal Transmission:

[0005] In traditional passive locks, the contact energy transmission method is relatively common. This scheme powers the passive lock from the key or controller end through physical contact points (such as metal interfaces) and transmits the unlocking signal at the same time. Its working principle is usually that the metal pins on the key contact the metal contacts on the lock, and the power supply at the key end powers the lock through the contact point, and the unlocking signal is transmitted to the lock through the same interface

[0006] The advantages of this contact transmission technology are as follows:

[0007] High power transmission efficiency: Due to physical contact, the energy loss is small and the power supply efficiency is high

[0008] Stable signal transmission: The signal is transmitted through a physical conductor, with less signal interference and better transmission stability

[0009] However, contact transmission also has significant disadvantages:

[0010] The contact points are prone to wear: As the number of uses increases, the metal interfaces are prone to wear, resulting in poor contact and affecting the stability of power supply and signal transmission

[0011] Prone to environmental influence: In humid, dusty or corrosive environments, the contact points are easily contaminated or oxidized, thereby affecting the transmission effect

[0012] High maintenance cost: Due to the wear and damage of the contact points, the equipment needs to be frequently maintained and replaced, increasing the usage cost

[0013] 2. Wireless Energy and Signal Transmission:

[0014] With the development of wireless technology, in recent years, passive locks have gradually adopted wireless energy transmission and wireless signal transmission solutions. Wireless energy transmission uses technologies such as inductive coupling and magnetic resonance to transmit electrical energy from the key or controller end to the passive lock through electromagnetic waves. Wireless signal transmission usually transmits the unlocking signal through wireless communication protocols such as Bluetooth, RFID, and NFC.

[0015] The advantages of wireless transmission technology are as follows:

[0016] Reduce physical wear: Since there is no need for physical contact, the wear problem of metal interfaces is avoided, and the service life of the device is extended.

[0017] Convenient to use: The wireless transmission method improves the convenience of use. Especially in scenarios where docking is difficult, users only need to bring the key close to the lock to complete power supply and unlocking operations.

[0018] However, there are also some technical bottlenecks in the wireless transmission method:

[0019] High system cost: Wireless transmission requires transmitting the energy and signal of the key to the lock. The lock judges the password match of the signal on the premise of obtaining energy and performs the unlocking operation under the condition of password match. It requires two modules of wireless energy transmission and wireless signal transmission, resulting in a relatively high hardware cost.

[0020] High system complexity: Existing wireless transmission systems usually need to process the transmission of energy and signal separately, resulting in complex hardware and software designs of the system and relatively high manufacturing costs.

[0021] Signal interference problem: Wireless signal transmission is easily interfered by the external environment, such as electromagnetic wave interference and metal shielding, especially by the high-frequency electromagnetic field interference of its own wireless energy transmission, resulting in unstable unlocking signals. Especially in complex environments, there may be signal delays or losses.

[0022] However, both contact transmission and wireless transmission in the prior art have limitations: 1. Separation of energy and signal transmission methods: Existing wireless transmission systems usually separate energy transmission and signal transmission, increasing the complexity of the system. Two independent transmission modules are required, one for wireless power supply and the other for signal transmission. The system is not only complex in design and high in manufacturing cost, but also the interference problem between the two is difficult to avoid. 2. Poor synchronization of energy and signal: Due to the use of two independent modules to transmit energy and signal respectively, it is difficult to synchronize the signal received by the key with the energy. If the signal is received earlier than the energy, the signal cannot be processed because the lock is not powered. If the signal is received later than the energy, the lock needs to be charged for a long time, resulting in a decrease in the energy utilization rate of the key. 3. Poor system stability: Since wireless transmission is vulnerable to environmental interference, especially in scenarios with strong electromagnetic interference with similar frequencies and a large number of metal shields, it is difficult to ensure the stability and accuracy of signal transmission, affecting the user experience and the reliability of the device. 4. High maintenance cost: Although the contact transmission scheme is stable, due to the wear and pollution problems of the contact points, regular maintenance or replacement is required, increasing the operating cost. Summary of the Invention

[0023] Aiming at the defects existing in the prior art, the technical problem solved by the present invention is: to provide a method for energy transmission and signal transmission of a passive wireless lock, which can reduce the complexity of the system and the manufacturing cost, while improving the synchronization of energy and signal transmission, enhancing the stability of signal transmission, and improving the durability of the device, to solve the many problems existing in the prior art regarding the energy transmission and signal transmission methods of passive locks, such as complex systems, separation of energy and signal transmission, and susceptibility to interference of signals.

[0024] To achieve the above object, the present invention provides:

[0025] A method for energy transmission and signal transmission of a passive wireless lock, comprising the following steps:

[0026] S1: Insert the key into the keyhole, press the key button to start the energy transmission module, and monitor the current value output by the key power supply to the energy transmission module;

[0027] The current value when the key button is pressed when the key is not inserted into the keyhole is I N , and the maximum current value when the key button is pressed when the key is inserted into the keyhole is I max , after I max delay for t s , (t s is 0.5 s to 2 s) the current value is I L .

[0028] If I max <1.5*I N, indicating that the key is not inserted correctly into the lock hole, and an alarm signal is sent through the key;

[0029] If I L > 1.2 * I N , indicating that the energy receiving module of the lock is overloaded, and an alarm signal is sent through the key;

[0030] If I max ≥1.5 * I N and I L ≤1.2 * I N , indicating that the energy receiving module of the lock is working properly;

[0031] S2: When the energy receiving module of the lock is normal, by changing the continuous power supply of the energy sending module to pulsed power supply, the pulse is generated by the signal encoding module controlling the switch (the switch is a MOS transistor) between the power supply and the energy sending module. The duration period and change rule of the high level and low level of the pulse represent the unlocking password sent, that is, the sent unlocking password is superimposed on the wireless energy transmission process;

[0032] Taking a high level lasting more than 0.5 s as the start and end signal, after the start and end signal, a low level lasting 0.1 s, and then a high level from 0.1 s to 0.4 s as the information encoding, respectively representing 0 to 3. Each information encoding is separated by a low level lasting 0.1 s. Multiple information encodings form a quaternary unlocking password. After completing the unlocking password, a low level lasting 0.1 s, and then a high level lasting more than 0.5 s as the start and end signal, and the unlocking password is cyclically generated and superimposed and sent through the wireless energy transmission process.

[0033] S3: When the energy receiving module of the lock is normal, the energy signal received by the energy receiving module is respectively sent to the signal decoding module through an RC low-pass filter, and the energy storage capacitor is charged through a diode;

[0034] S4: The signal decoding module records the duration of each high level, forming an array [N1, N2, …, N n , with the unit of ms;

[0035] Judging the values in the array one by one from the beginning. If N k (k = 1, 2, …, n) is greater than 450, then start taking numbers from N k+1 . Assuming that after N k+1 , N m (m = k + 2, k + 3, …, n) is the first number greater than 450, then the received unlocking password is [N k+1 , N k+2 , …, N m-1 .

[0036] Perform unlocking calculation. Assume the unlocking password built into the lock is [X1, X2, …, X p (the value of each digit ranges from 0 to 3). If the length of the received unlocking password is not equal to the length of the built-in unlocking password, it is regarded as unlocking failure. If the length of the received unlocking password is equal to the length of the built-in unlocking password, perform password comparison:

[0037] [dX1, dX2, …, dX p = [X1, X2, X3, …, X p * 100 - [N k+1 , N k+2 , …, N m-1 + 100

[0038] Calculate the root mean square of [dX1, dX2, dX3, …, dX p . If the root mean square is less than or equal to 10, it indicates unlocking success. If the root mean square is greater than 10, it indicates unlocking failure.

[0039] After unlocking failure, start taking numbers again from N m+1 to form a new received unlocking password and perform unlocking calculation again.

[0040] If unlocking fails continuously 3 to 5 times (determined by the user), the lock emits an alarm signal, this unlocking ends, the signal decoding module no longer decodes, and it is necessary to move the key away, disconnect the lock, and recharge it before decoding again.

[0041] S5: On the premise of unlocking success, the signal decoding module controls the switch (the switch is a MOS transistor) between the energy storage capacitor and the load to conduct, the load is powered on, the unlocking mechanism operates, the lock opens, and the lock emits an unlocking success signal.

[0042] S6: After step S2 and later, monitor the current value output by the key power supply to the energy sending module. When the maximum value I max2 ≥ I max , it indicates unlocking success, and the key records the unlocking success information. Otherwise, it indicates unlocking failure, and the key records the unlocking failure information.

[0043] Preferably, in S1, the key end sends energy. The key end sends intermittent pulse energy through the wireless transmission module according to the set time coding rule;

[0044] Preferably, in S1, the duration of each pulse is different, representing different binary information. A long pulse of 0.1 s represents "1", and a short pulse of 0.05 s represents "0".

[0045] Preferably, in S1, at the start and end of the transmission, the key end sends a long pulse with a duration exceeding 0.5 s to indicate the start and end of the signal transmission.

[0046] Preferably, in S2, after the wireless receiving module at the lock end receives the pulse energy, it first enters the synchronization state and recognizes the start pulse of the transmission.

[0047] Preferably, in S2, the lock monitors the duration of each pulse in real time through an internal decoding circuit and decodes it into the corresponding binary signal.

[0048] Preferably, in S2, after the decoding is completed, the control circuit inside the lock verifies the signal to ensure the integrity and accuracy of the signal.

[0049] Preferably, in S3, the energy transmission and signal transmission are integrated into a single wireless transmission path.

[0050] Preferably, in S4, a low-power, high-frequency wireless transmission band is adopted to reduce electromagnetic interference in the daily environment;

[0051] Dynamic frequency adjustment: During the signal transmission process, the system can dynamically adjust the transmission frequency according to environmental conditions to avoid interference frequency bands and ensure the stability of signal transmission;

[0052] Redundancy design: During the signal transmission process, redundant codes and check codes are added to ensure accurate decoding of the signal and transmission reliability.

[0053] Preferably, in S5, dynamic encryption is adopted: During each transmission of the unlocking signal, a dynamic encryption algorithm is used to ensure the uniqueness and timeliness of the signal and prevent signal replay attacks;

[0054] Two-way authentication is adopted: Before the signal transmission between the key end and the lock end, two-way authentication is carried out to ensure that energy and signal transmission can only be carried out after the identity verification of both parties is passed.

[0055] Compared with the prior art, the advantages of the present invention are as follows:

[0056] 1. Simplify the system design and reduce the manufacturing cost:

[0057] In the prior art, energy transmission and signal transmission are usually carried out through two independent modules, which increases the complexity and manufacturing cost of the system. The first objective of the present invention is to integrate energy transmission and signal transmission into a single system through an innovative design, reduce the number of transmission modules, and thus simplify the system design. Through the integrated design scheme, the manufacturing cost is reduced, and at the same time, the volume of the system is reduced, making the device more compact and portable.

[0058] 2. Improve energy transmission efficiency:

[0059] In existing wireless energy transmission technologies, due to the low energy conversion efficiency, the power supply speed of passive locks is relatively slow, affecting the user experience. The second objective of the present invention is to optimize the wireless energy transmission method, such as adopting efficient magnetic resonance technology or inductive coupling technology, to improve the energy transmission efficiency and reduce energy loss. By increasing the energy transmission efficiency and shortening the power supply time, the passive lock can obtain sufficient electrical energy more quickly, enhancing the response speed of the entire system.

[0060] 3. Improve the stability and anti-interference ability of signal transmission:

[0061] Wireless signal transmission technologies (such as Bluetooth, RFID, NFC, etc.) are prone to electromagnetic interference or metal shielding in complex environments, resulting in unstable signal transmission and affecting the accuracy of unlocking. The third objective of the present invention is to optimize the signal transmission path and protocol to improve the stability and anti-interference ability of signal transmission. Whether in a strong electromagnetic interference environment or a scenario with strong metal shielding, the system can ensure the accurate and reliable transmission of wireless unlocking signals, reducing signal loss and delay.

[0062] 4. Reduce the mutual interference between energy and signal transmission:

[0063] In existing wireless transmission systems, since energy transmission and signal transmission are carried out through two independent modules, mutual interference may occur, affecting the overall performance of the system. The fourth objective of the present invention is to optimize the energy and signal transmission paths through integrated design to reduce the interference between the two. Through reasonable frequency allocation, transmission protocol design, and physical isolation means, it is ensured that energy transmission and signal transmission can be carried out efficiently and independently, thereby enhancing the stability and reliability of the system.

[0064] 5. Improve the durability and adaptability of the system:

[0065] The present invention also aims to improve the durability of the entire system by reducing physical contact points. Traditional contact-based energy and signal transmission methods often affect the lifespan and performance of devices due to problems such as wear and pollution of contact points caused by long-term use. The present invention avoids the wear problem of physical contact points through wireless transmission, significantly increasing the service life of the device. In addition, the present invention also optimizes the adaptability of wireless transmission, enabling it to work stably in various complex environments (such as humid, dusty, or metal environments), reducing the maintenance frequency and cost.

[0066] 6. Improve the user experience and enhance the convenience of the system:

[0067] Existing wireless energy transmission and signal transmission technologies sometimes require users to interact with keys and locks at specific locations or in specific environments, and the operation is not intuitive and convenient enough. Another objective of the present invention is to enable users to perform unlocking operations more naturally and conveniently by optimizing the wireless transmission range and induction sensitivity. The user only needs to bring the key or controller close to the passive lock, without precise docking, to complete the energy supply and the transmission of the unlocking instruction, significantly improving the user experience.

[0068] 7. Enhanced security:

[0069] In the fields of commodity display and anti-theft, security is of utmost importance. In the prior art, the security of signal transmission is often affected by the external environment and there is a risk of being intercepted or cracked. The seventh objective of the present invention is to ensure the security of signal transmission by designing a more secure encryption communication protocol. By adopting means such as dynamic encryption technology and two-way authentication, the security of the unlocking signal during transmission is ensured, the anti-cracking ability of the system is improved, and the anti-theft effect is enhanced.

[0070] 8. Wide range of application scenarios:

[0071] Another important objective of the present invention is to provide a general solution for various fields such as commodity display anti-theft, intelligent door locks, and intelligent warehousing. Whether it is an anti-theft system for high-end commodity display cabinets or an access control system for smart homes, the method of the present invention is applicable and has good scalability, compatibility, and flexibility, and can meet the requirements under different application scenarios.

[0072] 9. Development trend:

[0073] With the rapid development of the Internet of Things, smart homes, and intelligent security systems, the market demand for passive locks with high efficiency, stability, and low maintenance costs is increasing day by day. The future development trend is to integrate energy transmission and signal transmission into one, reduce the complexity of the system, and at the same time improve the transmission efficiency and signal stability. In addition, how to ensure the stability and anti-interference ability of the wireless transmission system in complex environments is also an important technical challenge faced by the industry.

[0074] The present invention is based on existing low-power wireless energy transmission technologies such as electromagnetic induction or magnetic resonance, but innovatively improves the energy transmission mode. In traditional wireless energy transmission, the energy transfer is continuous and only used for power supply. By sending the energy in the form of intermittent pulses, not only the power supply function is realized, but also the signal transmission is realized through the timing coding of the pulses. Through this pulse coding mechanism, energy transmission and signal transmission no longer require independent hardware modules, which not only simplifies the system design but also improves the transmission efficiency. Description of the Drawings

[0075] Figure 1Schematic diagram of the overall structure of the wireless lock system of this design;

[0076] Figure 2 Schematic diagram of the wireless energy transmission module at the key end of this design;

[0077] Figure 3 Schematic diagram of the wireless energy reception and decoding module of the passive lock in this design. Specific implementation mode

[0078] The following further elaborates on the embodiments of the present invention in conjunction with the accompanying drawings.

[0079] See Figures 1-3 As shown, a method for energy transmission and signal transmission of a passive wireless lock includes the following steps:

[0080] S1: Energy transmission at the key end; When the key is inserted into the lock hole and the key button is pressed, the energy transmission module is activated, and the current value output from the key power supply to the energy transmission module is monitored;

[0081] The current value when the key button is pressed without the key inserted into the lock hole is I N , and the maximum current value when the key is inserted into the lock hole and the button is pressed is I max , after I max a delay of t s , (t s is 0.5 s to 2 s) the current value is I L .

[0082] If I max < 1.5*I N , it indicates that the key is not correctly inserted into the lock hole, and an alarm signal is sent through the key;

[0083] If I L > 1.2*I N , it indicates that the energy reception module of the lock is overloaded, and an alarm signal is sent through the key;

[0084] If I max ≥ 1.5*I N and I L ≤ 1.2*I N , it indicates that the energy reception module of the lock is operating normally.

[0085] S2: Energy reception and decoding at the lock end; When the energy reception module of the lock is normal, by changing the continuous power supply of the energy transmission module to pulsed power supply, the pulse is generated by controlling the switch (the switch is a MOS transistor) between the power supply and the energy transmission module by the signal encoding module, and the duration period and change rule of the high level and low level of the pulse represent the unlocking password sent, that is, the sent unlocking password is superimposed on the wireless energy transmission process;

[0086] Use a high level lasting more than 0.5s as the start-stop signal. After the start-stop signal, there is a low level lasting 0.1s, and then a high level lasting from 0.1s to 0.4s is used as the information code, representing 0 to 3 respectively. Each information code is separated by a low level lasting 0.1s. Multiple information codes form an unlocking password in quaternary format. After the unlocking password is completed, there is a low level lasting 0.1s, and then a high level lasting more than 0.5s is used as the start-stop signal again, generating the unlocking password cyclically and transmitting it superimposed through the wireless energy transmission process.

[0087] S3: Unlock and feedback; When the energy receiving module of the lock is normal, the energy signals received by the energy receiving module are respectively sent to the signal decoding module through an RC low-pass filter, and the energy storage capacitor is charged through a diode.

[0088] S4: Improve the anti-interference ability during the transmission process; The signal decoding module records the duration of each high level to form an array [N1, N2, …, N n , with the unit of ms;

[0089] Judge the values in the array one by one from the beginning. If N k (k = 1, 2, …, n) is greater than 450, then start taking numbers from N k+1 . Assume that after N k+1 , N m (m = k + 2, k + 3, …, n) is the first number greater than 450, then the received unlocking password is [N k+1 , N k+2 , …, N m-1 .

[0090] Perform the unlocking calculation. Assume that the built-in unlocking password of the lock is [X1, X2, …, X p (the value of each digit is 0 to 3). If the length of the received unlocking password is not equal to the length of the built-in unlocking password, it is regarded as unlocking failure. If the length of the received unlocking password is equal to the length of the built-in unlocking password, perform password comparison:

[0091] [dX1, dX2, …, dX p = [X1, X2, X3, …, X p * 100 - [N k+1 , N k+2 , …, N m-1 + 100

[0092] Calculate the root mean square of [dX1, dX2, dX3, …, dX p . If the root mean square is less than or equal to 10, it means unlocking success. If the root mean square is greater than 10, it means unlocking failure.

[0093] After the unlocking fails, start fetching numbers again from N m+1 to form a new received unlocking password and perform the unlocking calculation again.

[0094] If the unlocking fails continuously 3 to 5 times (determined by the user), the lock emits an alarm signal, this unlocking ends, the signal decoding module no longer decodes, and it is necessary to move the key away and disconnect and recharge the lock before decoding can be performed again.

[0095] S5: Improve system security; on the premise of successful unlocking, the signal decoding module controls the switch (the switch is a MOS transistor) between the energy storage capacitor and the load to conduct, the load is powered on, the unlocking mechanism operates, the lock opens, and the lock emits a signal indicating successful unlocking.

[0096] S6: After step S2 and later, monitor the current value output by the key power supply to the energy transmission module. When the maximum value I max2 ≥I max it indicates successful unlocking, and the key records the information of successful unlocking, otherwise it indicates failed unlocking, and the key records the information of failed unlocking.

[0097] In this embodiment, in S1, the key end transmits energy. The key end, through the wireless transmission module, according to the set time coding rule, transmits intermittent pulse energy. Each pulse has a different duration, representing different binary information. A long pulse of 0.1s represents "1", and a short pulse of 0.05s represents "0". At the start and end of the transmission, the key end sends a long pulse with a duration exceeding 0.5s to indicate the start and end of the signal transmission.

[0098] In this embodiment, in S2, after the wireless receiving module at the lock end receives the pulse energy, it first enters the synchronization state, recognizes the starting pulse of the transmission. The lock, through the internal decoding circuit, monitors the duration of each pulse in real time and decodes it into the corresponding binary signal. After the decoding is completed, the control circuit inside the lock checks the signal to ensure the integrity and accuracy of the signal.

[0099] In this embodiment, in S3, after verification, if the received signal matches the preset unlocking password, the lock performs the unlocking operation, and the lock sends a feedback signal to the key end through the wireless module to indicate success or failure of unlocking.

[0100] In this embodiment, in S3, the energy transmission and signal transmission are integrated in one wireless transmission path;

[0101] Specifically, 1. Design of the energy and signal transmission module at the key end

[0102] The core of the key end design is to generate pulsed wireless energy that can both transfer energy and carry signals by controlling the working state of the DC power supply. The specific structure is as follows:

[0103] DC power supply:

[0104] The DC power supply at the key end provides stable high-level energy as the basic power supply for the system.

[0105] Signal encoding module:

[0106] The signal encoding module generates low-frequency pulse signals and realizes signal encoding by controlling the conduction and disconnection of the DC power supply. The specific implementation is as follows:

[0107] The signal encoding module converts the password into a binary signal sequence (such as "1010") according to the set unlocking password.

[0108] The signal is encoded into low-frequency pulses by controlling the length of the conduction time of the DC power supply:

[0109] A long conduction time (0.1 s) represents binary "1".

[0110] A short conduction time (0.05 s) represents binary "0".

[0111] At the beginning and end of signal transmission, a long pulse with a duration exceeding 0.5 s is sent to identify the start and end of communication.

[0112] Energy transmission module:

[0113] The low-frequency pulse signal generated by the signal encoding module directly controls the working state of the energy transmission module. The implementation details of the energy transmission module are as follows:

[0114] (1) When the DC power supply is in the conduction state, the energy transmission module converts the high-level DC energy into high-frequency alternating pulse energy and sends it out through wireless transmission.

[0115] (2) The frequency range of the high-frequency pulse is set according to the frequency band requirements of wireless transmission (such as 13.56 MHz or other appropriate frequencies) to ensure the efficiency and stability of energy transmission.

[0116] With this design, while the key end sends energy, the signal is embedded in the low-frequency pulse of the energy, thus realizing the integrated transmission of energy and signal.

[0117] 2. Design of the energy and signal receiving module of the passive lock end

[0118] The core of the passive lock end is to extract DC energy and the embedded low-frequency signal from the received high-frequency pulse energy at the same time. The specific structure is as follows:

[0119] Energy receiving module:

[0120] The passive lock end receives the high-frequency pulsed wireless energy sent by the key end through the energy receiving module and divides it into two parts for processing.

[0121] Energy extraction part:

[0122] The high-frequency pulse is rectified and smoothed through a filter capacitor (such as an energy storage capacitor) and converted into a stable DC power supply for powering the load of the passive lock.

[0123] The designed capacity of the filter capacitor can meet the instantaneous power demand of the passive lock load and ensure the stability of power supply.

[0124] Signal extraction part:

[0125] The received high-frequency pulse signal is processed through an RC low-pass filter (composed of a resistor and a capacitor) to filter out the low-frequency pulse signal.

[0126] The design parameters of the RC low-pass filter (such as the resistor and capacitor values) are set according to the frequency of the low-frequency pulse signal sent by the key end to ensure accurate extraction of the low-frequency pulse signal consistent with the signal coding module of the key end.

[0127] Signal decoding module:

[0128] The signal decoding module decodes the low-frequency pulse signal output from the RC low-pass filter and restores the binary signal sequence sent by the key end. The specific implementation is as follows:

[0129] (1) The decoding module measures the duration of each low-frequency pulse:

[0130] (1) A pulse with a duration of 0.1 s is decoded as binary "1".

[0131] (2) A pulse with a duration of 0.05 s is decoded as binary "0".

[0132] (2) The decoding module uses the start and end identifiers of the unlocking signal (long pulses exceeding 0.5 s) as the boundaries of the data frame to ensure the integrity of the signal.

[0133] (3) By comparing the decoded signal sequence with the preset unlocking password, it is judged whether the unlocking signal is correct.

[0134] 3. Timing design for integrated transmission of energy and signal

[0135] The key to the integrated design of energy and signal transmission lies in the reasonable arrangement of timing to ensure the integrity of signal transmission and the continuity of energy supply. The following are the specific details of the timing design:

[0136] Pulse timing rule:

[0137] The pulse signals sent by the key end follow the following rules:

[0138] Each pulse consists of two phases: the conduction phase (sending high-frequency energy) and the disconnection phase (no energy transmission).

[0139] The conduction time of the pulse represents binary data according to the signal coding rule (for example, a long pulse represents "1" and a short pulse represents "0").

[0140] The time interval of the disconnection phase is set to a fixed value (such as 0.02 s) to distinguish different pulse signals.

[0141] Synchronization of signal and energy:

[0142] (1) During the conduction phase, the high-frequency pulse not only powers the passive lock but also transmits signal coding information.

[0143] (2) The disconnection phase of the pulse does not affect the energy supply because the filter capacitor can continuously supply electrical energy to the load of the passive lock during the disconnection phase.

[0144] Integrity of signal transmission:

[0145] (1) By adding identification long pulses (exceeding 0.5 s) at the beginning and end of the pulse sequence, the integrity of the signal transmission frame is ensured.

[0146] (2) The passive lock end enters the signal decoding state by detecting the identification pulse and exits the decoding state after receiving the complete frame.

[0147] 4. Parameter design of key modules

[0148] Design of RC low-pass filter:

[0149] According to the frequency of the low-frequency pulse signal (such as 10 Hz), the cut-off frequency of the RC filter is designed to be 1.5 to 2 times of this frequency (such as 15 Hz - 20 Hz) to ensure the filtering accuracy of the low-frequency signal.

[0150] The typical values of the filtering resistor and capacitor can be selected as: resistor 10 kΩ, capacitor 10 μF (the specific values can be adjusted according to the actual frequency).

[0151] Design of filter capacitor:

[0152] (1) The filter capacitor is used to rectify the high-frequency pulse into a DC power supply, and its capacity needs to meet the instantaneous power demand of the passive lock load.

[0153] The typical capacity range can be selected from 10 μF to 100 μF, and the specific value is calculated according to the actual power consumption of the lock.

[0154] In this embodiment, frequency band optimization: adopt a low-power and high-frequency wireless transmission frequency band, select a suitable wireless frequency band, and reduce electromagnetic interference in the daily environment;

[0155] Specifically, 1. Select a suitable wireless transmission frequency band

[0156] The selection of the wireless transmission frequency band is based on the following core factors: power limitation, transmission efficiency, anti-interference ability, and the usage specifications of existing frequency bands. The frequency band optimization designed by the present invention is mainly reflected in the following aspects:

[0157] Use a high-frequency transmission frequency band:

[0158] The present invention preferably uses a high-frequency range (such as 13.56 MHz, 915 MHz, 2.4 GHz, etc.), because high-frequency signals have the following advantages:

[0159] Higher transmission efficiency: Due to the shorter wavelength, high-frequency signals have a higher energy transmission efficiency in electromagnetic induction or magnetic resonance wireless transmission.

[0160] Smaller antenna size: The antenna size required for high-frequency signals is smaller, which is beneficial to the miniaturized design of the system hardware.

[0161] Strong anti-interference ability: High-frequency signals have less interference with other low-frequency devices within a certain range, and it is also easier to avoid common interference signals in the low-frequency band.

[0162] Avoid crowded frequency bands:

[0163] (1) The wireless transmission frequency band needs to avoid widely used crowded frequency bands (such as some public low-frequency bands) to reduce signal interference.

[0164] (2) For example, use the 13.56 MHz frequency band (an ISM frequency band that meets international standards), which is suitable for short-distance and low-power wireless transmission, widely used in technologies such as RFID and NFC, and is relatively clean with less interference.

[0165] ISM frequency band that meets international specifications:

[0166] The low-power transmission frequency band adopted by the present invention preferably selects the ISM (Industrial, Scientific and Medical) frequency band that meets international standards, such as:

[0167] (1) 13.56 MHz (low frequency, suitable for short-distance transmission, high transmission stability).

[0168] (2) 915 MHz (low-frequency UHF, suitable for medium-distance transmission, strong signal penetration).

[0169] (3) 2.4 GHz (high frequency, suitable for short-distance high-speed transmission, but vulnerable to metal environment interference).

[0170] These frequency bands are protected by international radio regulations and do not require special frequency band authorization, making them suitable for low-power wireless transmission applications.

[0171] 2. Specific implementation of high-frequency transmission

[0172] The optimized design of the high-frequency transmission frequency band involves the hardware and signal processing modules of the transmitting end (key) and the receiving end (passive lock), and the specific implementation is as follows:

[0173] High-frequency energy transmission module at the key end:

[0174] High-frequency signal generation:

[0175] An oscillator circuit (such as a crystal oscillator) is used at the key end to generate a high-frequency signal of the target frequency. For example, a 13.56 MHz signal can be generated and amplified by a quartz crystal oscillator.

[0176] Carrier modulation:

[0177] Based on the high-frequency signal, pulse coding technology is used to modulate the carrier to form a high-frequency transmission signal containing a low-frequency pulse signal. The modulation methods can be:

[0178] ASK (Amplitude Shift Keying): The signal information is carried by changing the amplitude of the high-frequency signal, which is suitable for power-sensitive scenarios.

[0179] FSK (Frequency Shift Keying): The signal information is transmitted by changing the frequency of the high-frequency signal, which has stronger anti-interference ability.

[0180] Low-power design:

[0181] The transmission power is limited within an appropriate range (such as less than 100 mW) through a power control module to ensure compliance with the low-power wireless transmission specification and avoid interference with devices in other frequency bands.

[0182] 3. High-frequency energy reception module at the passive lock end:

[0183] (1) High-frequency receiving antenna design:

[0184] The passive lock end is equipped with a high-frequency receiving antenna, whose size and design parameters match the selected frequency band. For example, antennas for the 13.56 MHz frequency band usually adopt a spiral structure or a flat coil, with a small size and suitable for embedded applications.

[0185] (2) High-frequency signal demodulation:

[0186] The received high-frequency signal extracts the contained low-frequency pulse signal through a demodulation circuit (such as a diode detector or a mixer). The demodulation process includes:

[0187] (1) Detect the amplitude or frequency change of the carrier signal and extract the signal information transmitted therein.

[0188] (2) Restore the pulse code signal and provide input data for the subsequent decoding module.

[0189] (3) Energy extraction and rectification:

[0190] The high-frequency energy is converted into DC energy through a rectification circuit (such as a diode bridge rectifier) to power the load of the passive lock.

[0191] 4. Anti-interference strategy with optimized frequency band

[0192] The design of the optimized frequency band not only requires selecting a suitable frequency band but also taking measures to enhance the anti-interference ability of the transmission, as follows:

[0193] First, dynamic frequency adjustment:

[0194] If there is an interference source (such as other wireless devices) within the target frequency band, the key end can dynamically switch to an adjacent alternate frequency band through the frequency adjustment module. For example, when the 13.56 MHz frequency band is interfered with, it can be switched to a higher frequency (such as 14 MHz).

[0195] The algorithm for dynamic frequency adjustment is based on the real-time monitored signal strength and interference level, and ensures the stability of the transmission by selecting the frequency band with the least interference.

[0196] Second, narrowband transmission:

[0197] (1) The transmission frequency bands of the key end and the passive lock end are designed for narrowband transmission (such as a width of ±10 kHz) to reduce the interference impact within the frequency band.

[0198] (2) The design of the narrowband signal enhances the anti-interference ability of the signal through the method of concentrated power transmission.

[0199] Third, shielding interference design:

[0200] (1) The key electronic components (such as the transmitting module and the receiving module) of the key end and the passive lock end adopt a shielded housing design to reduce the impact of external electromagnetic interference on signal transmission.

[0201] 5. Hardware design details of the optimized high-frequency transmission frequency band

[0202] First, hardware design of the transmitting end (key):

[0203] Oscillator: A quartz crystal oscillator is used to generate a stable high-frequency signal (such as 13.56 MHz).

[0204] Modulation circuit: Use an ASK modulator to superimpose a low-frequency pulse signal on a high-frequency carrier wave.

[0205] Power amplification circuit: Boost the intensity of the transmitted signal through a power amplifier, and strictly control the power range within the low-power (such as 1 - 100 mW) specification.

[0206] Matching network: Improve the energy transfer efficiency of the antenna through an impedance matching circuit.

[0207] Second, hardware design of the receiving end (passive lock):

[0208] (1) Receiving antenna: Designed as a high-frequency antenna (such as a helical antenna) that matches the target frequency band.

[0209] (2) Demodulation circuit: Use a diode detector or mixer to extract the pulse signal in the carrier wave.

[0210] (3) Rectification circuit: Convert the high-frequency pulse signal into a DC power supply through a bridge rectifier.

[0211] In this embodiment, dynamic frequency adjustment: During the signal transmission process, the system can dynamically adjust the transmission frequency according to environmental conditions, avoid interference frequency bands, and ensure the stability of signal transmission;

[0212] Specifically, 1. The core principle of dynamic frequency adjustment

[0213] Dynamic frequency adjustment is based on the principle of Frequency Hopping (FH) technology. It avoids the influence of interference by switching the transmission frequency among multiple available frequency bands. The core workflow of this technology is as follows:

[0214] Frequency band division:

[0215] Pre-divide multiple available frequency bands within the wireless transmission range. For example, divide multiple sub-frequency bands such as 13.50 MHz, 13.55 MHz, 13.60 MHz, etc. near the 13.56 MHz frequency band.

[0216] The frequency bandwidth of each sub-frequency band is usually between 10 kHz and 50 kHz to cover an appropriate transmission range.

[0217] Real-time interference detection:

[0218] (1) The system determines whether the current frequency band is interfered with by monitoring the interference intensity (such as signal-to-noise ratio SNR or signal strength RSS1) of the current transmission frequency band.

[0219] (2) If the signal quality of the current frequency band is detected to be lower than the set threshold, the system will trigger the frequency switching mechanism.

[0220] Frequency hopping:

[0221] (1) The system selects a new frequency band with lower interference from a pre-defined list of frequency bands for transmission.

[0222] (2) The hopping mechanism can be random or based on a pre-set frequency hopping sequence or algorithm (such as a pseudo-random sequence).

[0223] Frequency synchronization:

[0224] (1) To ensure that the transmitter (key) and the receiver (passive lock) can still communicate normally after switching frequencies, the system maintains the frequency consistency between the transmitter and the receiver through synchronization signals or protocols.

[0225] 2. Implementation of dynamic frequency adjustment at the key end

[0226] Frequency generation module:

[0227] The key end is equipped with a frequency synthesizer (such as a phase-locked loop PLL or a direct digital frequency synthesizer DDS) for dynamically generating different transmission frequencies.

[0228] The frequency synthesizer can quickly switch the output frequency according to the control signal, for example, from 13.56 MHz to 13.50 MHz or 13.60 MHz.

[0229] Interference detection module:

[0230] (1) The key end monitors the transmission quality of the current frequency band through a signal feedback mechanism, including the following parameters:

[0231] Signal strength (RSS1): The signal quality of the current frequency band is judged by detecting the return signal strength of the receiver.

[0232] Bit error rate (BER): The signal transmission accuracy of the current frequency band is judged by decoding and comparison.

[0233] (2) If it is found that the signal strength of the current frequency band decreases or the bit error rate increases, the system will trigger a frequency switch.

[0234] Frequency switching logic:

[0235] (1) The key end selects an available frequency band from the pre-defined list of frequency bands according to the interference detection result.

[0236] (2) After switching the frequency band, the key end notifies the passive lock end to adjust the frequency through a synchronization signal to ensure consistency between the two parties.

[0237] 3. Implementation of dynamic frequency adjustment at the passive lock end

[0238] Frequency receiving module:

[0239] The passive lock end is equipped with a broadband receiving module that can cover all available frequency bands (such as 13.50 MHz to 13.60 MHz).

[0240] The broadband receiving module adjusts the receiving frequency in real time through a frequency tracking mechanism to match the frequency switching of the key end.

[0241] Frequency tracking and synchronization:

[0242] (1) The passive lock end determines the current transmission frequency by detecting the synchronization signal sent by the key end.

[0243] (2) If a frequency change is detected, the passive lock end will adjust the receiving frequency through the internal frequency synthesis module to be consistent with the key end.

[0244] Signal processing and decoding:

[0245] (1) After adjusting the receiving frequency, the passive lock end demodulates and decodes the high-frequency signal to extract the transmitted low-frequency pulse signal.

[0246] 4. Implementation process of dynamic frequency adjustment

[0247] The following is the specific implementation process of dynamic frequency adjustment:

[0248] Initialize the frequency band: The transmitter (key) and the receiver (passive lock) select the default center frequency band (such as 13.56 MHz) for communication when starting up.

[0249] Real-time monitoring: The key end and the passive lock end monitor the signal quality of the current frequency band in real time to determine whether there is interference (such as a decrease in signal-to-noise ratio, an increase in bit error rate, etc.).

[0250] Trigger frequency hopping: If interference is detected, the key end triggers a frequency switch and selects a new frequency band for transmission (for example, switching from 13.56 MHz to 13.60 MHz). The key end transmits the new frequency information to the passive lock end through the synchronization signal.

[0251] Frequency synchronization: After receiving the synchronization signal, the passive lock end adjusts the receiving frequency to match the frequency of the key end. The two parties continue to communicate within the new frequency band.

[0252] Loop optimization: The system continuously monitors the frequency band quality throughout the transmission process. If the new frequency band is interfered with again, the above steps are repeated.

[0253] Redundancy design: During the signal transmission process, redundant codes and check codes are added to ensure the accurate decoding of the signal and the reliability of transmission;

[0254] Specifically, redundancy design realizes the functions of error detection and correction by attaching redundant information (such as redundant codes and check codes) to the original signal. Its core ideas include the following two parts:

[0255] 1. Adding redundant codes:

[0256] Redundant codes are additional information attached to the original signal (i.e., the binary sequence of the unlocking password) for detecting and correcting errors during transmission.

[0257] For example, by repeating part of the signal or adding check information (such as parity bits), the fault tolerance of the signal is improved.

[0258] 1. Adding check codes:

[0259] (1) Check codes are additional information generated by performing specific mathematical operations on the original signal for detecting whether errors occur during transmission.

[0260] (2) Check codes can be used for simple error detection (such as parity check) or complex error correction (such as cyclic redundancy check CRC).

[0261] 2. Generation of redundant codes and check codes at the key end

[0262] At the key end, the generation of redundant codes and check codes is one of the core functions of the signal encoding module, and the specific implementation is as follows:

[0263] 1. Signal encoding and redundancy design:

[0264] The key end generates the original binary signal sequence according to the set unlocking password. For example, the unlocking password is "1010".

[0265] On this basis, redundant information is added. For example:

[0266] Repeated code: Each bit of information is repeated for transmission. For example, "1010" becomes "11001100", and each bit is repeated twice to improve transmission reliability.

[0267] Parity check: One parity bit is attached to the end of each group of data for detecting whether single-bit errors occur during transmission.

[0268] The redundant signal sequence is transmitted after being encoded by low-frequency pulses. For example:

[0269] Encoded redundant signal: If "1010" is added with 1 check code to become "10101", the corresponding pulse signal sequence is generated through the pulse encoding module.

[0270] 2. Method for generating check codes:

[0271] The key end generates a check code through the following method:

[0272] (1) Parity check: Count the number of "1"s in each group of data:

[0273] (1) If the number of "1"s is odd, the check bit is "1";

[0274] (2) If the number of "1"s is even, the check bit is "0".

[0275] (2) Cyclic Redundancy Check (CRC):

[0276] (1) The key end performs binary operations (such as modulo-2 division) on the original signal through a specific generating polynomial to generate a check code of a fixed length (such as 8 bits or 16 bits).

[0277] (2) The check code is appended to the original signal to form a complete transmission data frame.

[0278] 3. Data frame design:

[0279] To ensure the integrity of the signal, the key end embeds the redundancy code and the check code into the complete data frame. Each frame includes:

[0280] (1) Start flag: Used to identify the start of the data frame (for example, a long pulse signal indicates the start).

[0281] (2) Data field: Contains the original signal and the redundancy code (such as a repetition code, parity check bit, or CRC code).

[0282] (3) End flag: Used to identify the end of the data frame (for example, a long pulse signal indicates the end).

[0283] (4) For example, after adding the parity check code to the original signal "1010", the data frame may be:

[0284] Start flag | 10101 (data and check code) | End flag.

[0285] 4. Resolution of the redundancy code and check code of the passive lock end

[0286] The passive lock end analyzes and checks the received pulse signal through a signal decoding module. The specific process is as follows:

[0287] First. Data decoding:

[0288] The passive lock end extracts the low-frequency pulse signal through an RC low-pass filter and decodes the pulse signal into a binary signal sequence.

[0289] The decoded signal may contain errors. For example, "10101" is decoded as "10100".

[0290] Second. Error Detection and Correction:

[0291] The passive lock terminal detects whether an error occurs during the transmission process by parsing the redundant code and the check code, and attempts to correct the error. The specific methods include:

[0292] (1) Parity Check:

[0293] Calculate the number of "1"s in the received signal and compare it with the check bit.

[0294] If the comparison result is inconsistent, it indicates that a single-bit error has occurred in the data.

[0295] (2) Repetition Code Error Correction:

[0296] If the repetition code mechanism is adopted (such as repeating each bit twice), the passive lock terminal determines the repeated data and selects the value that appears more frequently as the valid value. For example, "11001100" is decoded as "1010".

[0297] (3) CRC Check:

[0298] The passive lock terminal calculates the received complete data frame (including the check code) according to the same generating polynomial.

[0299] If the calculation result is 0, it indicates that no error has occurred in the data frame; otherwise, it indicates that there is an error in the data frame.

[0300] 5. Signal Verification and Correction:

[0301] If the verification result indicates that the signal has an error and cannot be corrected, the lock terminal will request the key terminal to retransmit the signal (triggered by resending the start flag) to ensure the complete reception of the signal.

[0302] In this embodiment, dynamic encryption is adopted: during each transmission of the unlocking signal, a dynamic encryption algorithm is used to ensure the uniqueness and timeliness of the signal and prevent signal replay attacks;

[0303] Specifically, the key terminal is responsible for generating the dynamically encrypted unlocking signal, and the specific implementation is as follows:

[0304] 6. Generation and Storage of Encryption Keys:

[0305] The key terminal and the passive lock terminal pre-share a symmetric encryption key (such as a 128-bit or 256-bit key).

[0306] The key can be set at the factory or dynamically changed through the key update mechanism.

[0307] The key is stored using hardware encryption storage (such as a security chip) or software encryption storage to prevent key leakage.

[0308] 7. Generation of dynamic parameters:

[0309] The key end generates dynamic parameters (i.e., encryption factors) before each signal transmission. Common dynamic parameters include:

[0310] (1) Timestamp: A time mark generated based on the current system time (such as seconds, milliseconds) to ensure the timeliness of the signal.

[0311] (2) Random number: An unpredictable random value generated by a random number generator.

[0312] (3) Counter: A count value that increments with each transmission to ensure the uniqueness of the signal and prevent duplication.

[0313] 8. Application of encryption algorithms:

[0314] The key end encrypts the signal using the dynamic parameters and the unlock password to generate a dynamic unlock signal. The following common symmetric encryption algorithms can be used for the encryption algorithm:

[0315] (1) AES (Advanced Encryption Standard): An efficient and secure symmetric encryption algorithm that supports key lengths of 128 bits, 192 bits, and 256 bits.

[0316] (2) DES / 3DES (Data Encryption Standard): An earlier symmetric encryption algorithm, but less secure than AES, mainly used in scenarios with low security requirements.

[0317] (3) ChaCha20: A lightweight encryption algorithm suitable for low-power devices.

[0318] (2) The encryption process is as follows:

[0319] (1) Encrypted data = Encrypt(key, unlock password + dynamic parameters)

[0320] (2) Among them, Encrypt represents the encryption algorithm, the unlock password is a preset unlock code, and the dynamic parameters are the timestamp, random number, or counter.

[0321] 9. Transmission of encrypted signals:

[0322] (1) The key end converts the encrypted signal into a wireless pulse signal through a pulse coding module and sends it to the passive lock end.

[0323] (2) Data frame structure:

[0324] Start identifier: Identifies the start of the signal.

[0325] Encrypted signal: contains the dynamically encrypted unlocking signal.

[0326] Check code: used to detect transmission errors.

[0327] End flag: indicates the end of the signal.

[0328] 10. Decryption and verification of the dynamically encrypted signal of the passive lock end

[0329] The passive lock end is responsible for receiving the dynamically encrypted signal and performing decryption and verification. The specific implementation is as follows:

[0330] First. Synchronization of dynamic parameters:

[0331] The passive lock end needs to synchronize dynamic parameters with the key end to correctly decrypt the received signal. The synchronization methods include:

[0332] Timestamp synchronization: The passive lock end maintains time synchronization with the key end based on its own time (usually with an error of no more than a few seconds).

[0333] Counter synchronization: The passive lock end maintains a counter that is consistent with the counter of the key end.

[0334] Random number transmission: If the dynamic parameter uses a random number, the key end needs to send the random number as part of the signal to the passive lock end.

[0335] Second. Signal decryption:

[0336] (1) The passive lock end uses the preset symmetric key and synchronized dynamic parameters to decrypt the received encrypted signal and restore the original unlocking password.

[0337] (2) Decryption formula:

[0338] (1) Unlocking password = Decrypt(key, received encrypted signal)

[0339] (2) Among them, Decrypt represents the decryption algorithm, which corresponds to the encryption algorithm of the key end.

[0340] Third. Unlocking password verification:

[0341] (1) The passive lock end compares the decrypted unlocking password with the preset password:

[0342] (1) If the passwords match and the dynamic parameters are valid, the unlocking operation is performed.

[0343] (2) If the passwords do not match or the dynamic parameters are invalid, unlocking is rejected.

[0344] Fourth. Anti-replay mechanism:

[0345] (1) The passive lock end records dynamic parameters to prevent reuse. For example:

[0346] (1) Timestamp verification: If the timestamp is earlier than the current time or outside the allowed time range, the signal is considered invalid.

[0347] (2) Counter verification: If the count value is less than or equal to the previously received count value, the signal is considered invalid.

[0348] Random number verification: If the random number is already in the history, the signal is considered invalid.

[0349] In this embodiment, two-way authentication is adopted: before the signal transmission between the key end and the lock end, two-way authentication is carried out to ensure that after the identity verification of both parties passes, the energy and signal can be transmitted.

[0350] Specifically, the two-way authentication process of the key end

[0351] In two-way authentication, the key end needs to prove its own identity and at the same time verify the identity of the lock end. The specific implementation is as follows:

[0352] 1. Key storage:

[0353] The key end stores a preset key (symmetric key) shared with the lock end or a private key (asymmetric key).

[0354] The key is stored in a secure chip or a hardware security module (HSM) to prevent key leakage.

[0355] 2. Generate challenge value:

[0356] (1) At the beginning of authentication, the key end generates a random number as the challenge value (Challenge).

[0357] (2) The challenge value is combined with the key through an encryption algorithm to generate authentication data and sent to the lock end.

[0358] 3. Verify the identity of the lock end:

[0359] (1) After the key end receives the response from the lock end, it decrypts and verifies the response using the shared key or the corresponding public key.

[0360] (2) If the decrypted data matches the expected value of the key end, it indicates that the identity of the lock end is legal.

[0361] 4. Return the authentication response:

[0362] (1) After verifying the identity of the lock end, the key end uses the challenge value sent by the lock end to calculate and generate its own authentication response and return it to the lock end.

[0363] (2) The response data is generated by an encryption algorithm combined with a shared key to ensure it cannot be forged.

[0364] 5. Two-way authentication process at the lock end

[0365] After the lock end receives the authentication request from the key end, the following operations need to be completed:

[0366] Key storage:

[0367] The lock end stores a preset key (symmetric key) shared with the key end or a public key (asymmetric key).

[0368] The key is stored in the hardware encryption module to ensure the security of the key.

[0369] 6. Receive and decrypt the challenge value from the key end:

[0370] (1) The lock end receives the challenge value sent by the key end and verifies the challenge value through an encryption algorithm combined with the shared key.

[0371] (2) After successful verification, it indicates that the key end is legitimate.

[0372] 7. Generate a response and return it:

[0373] (1) The lock end uses the challenge value sent by the key end, combines its own key, generates an authentication response, and returns it to the key end.

[0374] (2) The response data is generated by an encryption algorithm to ensure it cannot be forged.

[0375] 8. Send the challenge value:

[0376] The lock end generates a new random challenge value and sends it to the key end, requesting the key end to provide an authentication response.

[0377] 9. Verify the response from the key end:

[0378] After the lock end receives the response from the key end, it decrypts and verifies the response data through an encryption algorithm combined with the shared key.

[0379] If the verification is successful, it indicates that the identity of the key end is legitimate.

[0380] In this embodiment, Figure 1The power supply is a DC power supply that outputs a high level. The signal encoding module controls the on / off between the power supply and the energy transmission module. The on and off present a low-frequency pulse signal, and the length of the on time represents the signal encoding. The energy transmission module converts the high-level power energy in the on stage into high-low-alternating high-frequency pulse energy and transmits it. The energy reception module receives the high-frequency pulse energy. On the one hand, the high-frequency pulse forms a low-frequency pulse signal identical to the signal encoding module through an RC low-pass filter. On the other hand, it forms a high-level power supply through a filter capacitor for the load.

[0381] Key end structure:

[0382] (1) DC power supply:

[0383] The key end is equipped with a DC power supply that outputs stable high-level power energy, providing basic electrical energy for the entire system.

[0384] (2) Signal encoding module:

[0385] The signal encoding module is responsible for controlling the on / off between the DC power supply and the energy transmission module. A low-frequency pulse signal is generated by turning the power supply on and off. Among them:

[0386] The length of the on time represents the encoding information of the signal (for example, 0.1 s represents binary "1", and 0.05 s represents binary "0").

[0387] The signal encoding module converts the unlocking signal into a string of low-frequency pulse signals according to the preset encoding rules.

[0388] (3) Energy transmission module:

[0389] The energy transmission module converts the high-level power energy corresponding to the low-frequency pulse signal generated by the signal encoding module into high-low-alternating high-frequency pulse wireless energy.

[0390] During the conduction period of the DC power supply, the energy transmission module outputs a high-frequency pulse signal to complete the wireless transmission of energy.

[0391] Passive lock end structure:

[0392] (1) Energy reception module:

[0393] The passive lock end receives the high-frequency pulse wireless energy sent by the key end through the energy reception module. The received high-frequency energy is processed in the following two ways:

[0394] Low-frequency signal restoration: The high-frequency pulse signal passes through an RC low-pass filter to extract a low-frequency pulse signal identical to the signal encoding module at the key end.

[0395] Electrical energy extraction: The high-frequency pulse signal is processed by a filter capacitor to form a stable high-level DC power supply for powering the passive lock load.

[0396] (2) Signal decoding module:

[0397] The signal decoding module decodes the low-frequency pulse signal generated by the RC low-pass filter into the original binary signal sequence (such as "1" and "0"), and compares it with the preset unlocking password. If the signal decoding is successful and the password matches, the unlocking operation is performed.

[0398] (3) Load module:

[0399] The load module of the passive lock includes a lock body control circuit and an actuator. The load module is powered by the DC power supply provided by the energy receiving module, and performs specific unlocking actions after the signal decoding module issues an unlocking instruction.

[0400] The present invention is not limited to the above best implementation manner. Any person can obtain other various forms of products under the inspiration of the present invention. However, no matter what changes are made in its shape or structure, as long as it has the same or similar technical solutions as the present invention, they are all within the scope of its protection.

Claims

1. A method for energy transmission and signal transmission of a passive wireless lock, characterized in that: The following steps are involved: S1: Insert the key into the lock, press the key button, start the energy sending module, and monitor the current value output by the key power supply to the energy sending module; The current value when the key is pressed without being inserted into the keyhole is I N , the maximum current when the key is pressed when inserted into the keyhole is I max , in I max After delay t s , the current value is I L ; S2: When the energy receiving module of the lock is normal, the continuous power supply of the energy sending module is changed to pulse power supply. The pulse is generated by the switch between the power supply and the energy sending module controlled by the signal encoding module. The continuous cycle and change rule of the high level and low level of the pulse represent the sent unlocking password, that is, the sent unlocking password is superimposed in the wireless energy transmission process; A high level lasting more than 0.5s is used as the start and end signals. After the start and end signals, a low level lasting 0.1s is used, and then a high level of 0.1s to 0.4s is used as the information code, representing 0 to 3 respectively. Each information code is separated by a low level lasting 0.1s. Multiple information codes constitute the unlocking password in quaternary format. After the unlocking password is completed, a low level lasting 0.1s is used, and then a high level lasting more than 0.5s is used as the start and end signals. The unlocking password is generated cyclically and sent in a superimposed manner through the wireless energy transmission process; S3: When the energy receiving module of the lock is normal, the energy signal received by the energy receiving module is sent to the signal decoding module through the RC low-pass filter, and then charged to the energy storage capacitor through the diode; S4: The signal decoding module records the duration of each high level and forms an array [N1, N2, ..., N n ], unit is ms; Determine the values ​​in the array one by one from the beginning, N k (k=1,2,…,n) is greater than 450, then from N k+1 Start taking numbers at N k+1 Afterwards, N m (m=k+2,k+3,…,n) is the first number greater than 450, then the received unlock password is [N k+1 ,N k+2 ,…,N m-1 ]; Perform unlock calculation, assuming that the built-in unlock password of the lock is [X1,X2,…,X p ], if the length of the received unlock password is not equal to the length of the built-in unlock password, it is considered that the unlocking failed. If the length of the received unlock password is equal to the length of the built-in unlock password, the password comparison is performed: [dX1, dX2, …, dX p ]=[X1,X2,X3,…,X p ]*100-[N k+1 ,N k+2 ,…,N m-1 ]+100Calculate [dX1, dX2, dX3, …, dX p ], if the RMS is less than or equal to 10, it means the unlocking is successful, and if the RMS is greater than 10, it means the unlocking fails; If the unlock fails, m+1 Start to get data again, form a new received unlocking password, and perform unlocking calculation again; S5: On the premise of successful unlocking, the signal decoding module controls the switch between the energy storage capacitor and the load to turn on, the load is energized, the unlocking mechanism is activated, the lock is opened, and the lock sends a successful unlocking signal; S6: After step S2, monitor the current value output by the key power supply to the energy transmission module. When the maximum current value I max2 ≥I max , it indicates that the unlocking is successful, and the key records the unlocking success information; otherwise, it indicates that the unlocking fails, and the key records the unlocking failure information.

2. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S1, the key end sends energy. The key end sends intermittent pulse energy through a wireless transmission module according to a set time coding rule.

3. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S1, each pulse has a different duration, representing different binary information. A long pulse of 0.1s represents "1", and a short pulse of 0.05s represents "0". At the beginning and end of the transmission, the key end sends a long pulse with a duration of more than 0.5s, indicating the start and end of the signal transmission.

4. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S1: I max <1.5*I N , indicating that the key is not correctly inserted into the lock, and an alarm signal is issued through the key; I L >1.2*I N , indicating that the energy receiving module of the lock is overloaded, and an alarm signal is sent through the key; I max ≥1.5*I N And I L ≤1.2*I N , indicating that the lock's energy receiving module is working properly.

5. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S2, after receiving the pulse energy, the wireless receiving module at the lock end first enters the synchronization state and recognizes the starting pulse of the transmission.

6. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S2, the lock monitors the duration of each pulse in real time through an internal decoding circuit and decodes it into a corresponding binary signal.

7. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S2, after the decoding is completed, the control circuit inside the lock verifies the signal to ensure the integrity and accuracy of the signal.

8. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S3, energy transmission and signal transmission are integrated into one wireless transmission path.

9. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In the S4, a low-power, high-frequency wireless transmission band is used to reduce electromagnetic interference in daily environments; Dynamic frequency adjustment: During signal transmission, the system can dynamically adjust the transmission frequency according to environmental conditions to avoid interference frequency segments and ensure the stability of signal transmission; Redundant design: During signal transmission, redundant codes and check codes are added to ensure accurate signal decoding and transmission reliability.

10. The energy transmission and signal transmission method of a passive wireless lock according to claim 1, characterized in that: In S5, dynamic encryption is used: the unlocking signal uses a dynamic encryption algorithm during each transmission process to ensure the uniqueness and timeliness of the signal and prevent signal replay attacks; Two-way authentication is adopted: the key end and the lock end perform two-way authentication before signal transmission to ensure that energy and signal transmission can only be carried out after the identity authentication of both parties is passed.

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