An interlock mechanism for a terminal access device

Abstract

The utility model discloses a kind of interlocking mechanisms of terminal access device, belong to physical security equipment technical field.The mechanism includes drive circuit, mechanical blocking component and relay.Mechanical blocking component is set at access port, and its driver is preferably U-shaped nickel-titanium alloy shape memory alloy wire, and gate can be driven to slide along the guide groove in locking portion.Solenoid is connected in series in port power supply loop.Drive circuit can synchronously drive mechanical blocking component physical blocking port passage according to control signal, and control relay to open supply, to realize the double cooperative isolation of data and energy.The mechanism is also provided with the manual reset mechanism of key and biological characteristic verification, ensure safety recovery.The utility model solves the security risk that single power failure cannot prevent illegal equipment secondary access, provides quick response, isolation complete automatic physical protection.

Description

Technical Field

[0001] This utility model belongs to the technical field of Internet terminal access equipment, and specifically relates to an interlocking mechanism for a terminal access device. Background Technology

[0002] In scenarios with stringent security isolation requirements, such as the Industrial Internet and data centers, it is crucial to quickly disconnect unauthorized or threatening terminals from the network upon detection. Currently, common automated physical isolation solutions primarily rely on controlling relays to cut off power to the access ports. This method can momentarily disable equipment by cutting off power, forming the first line of defense.

[0003] However, this single power-off mechanism has a significant security flaw: it cannot prevent unauthorized devices from being reconnected or reactivated after a power outage. Once power is cut off, the port remains physically connectable. Attackers or malware can attempt to restore the connection or launch new attacks within a short period by unplugging and replugging devices, utilizing residual charge in the port, or drawing power from other devices via the data cable. Furthermore, in unattended or delayed situations, the port after a power outage is essentially in an "open and undefended" physical state, leaving a window for subsequent penetration. Therefore, isolation achieved solely through power outages is incomplete and unsustainable, with a fragile security boundary, and cannot cope with high-risk threats requiring absolute physical blockage.

[0004] The existing technology lacks an automated mechanism that can act synchronously with the power outage command and physically "lock" the access channel, thereby eliminating any possibility of secondary access. Utility Model Content

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution.

[0006] An interlocking mechanism for a terminal access device is disposed within a locking portion of the terminal access device's housing, and includes a drive circuit, a mechanical blocking component, and a relay. The drive end of the mechanical blocking component is connected to the output end of the drive circuit, and the actuating end of the mechanical blocking component is disposed at the access port of the terminal access device, used to perform linear motion under the control of the drive circuit to physically block or open the access port; the coil of the relay is connected to the output end of the drive circuit, and the switching contacts of the relay are connected in series in the power supply circuit of the access port.

[0007] Furthermore, the mechanical blocking assembly includes a driver and a gate; the locking part is provided with a guide groove, and the gate is slidably assembled in the guide groove; the driver is connected to the gate and is used to drive the gate to slide along the guide groove; when the gate slides to the first position, the access port is opened; when the gate slides to the second position, the access port is physically blocked.

[0008] Furthermore, the actuator is a U-shaped nickel-titanium alloy shape memory alloy wire, with both ends of the shape memory alloy wire fixed to the locking part and the middle part connected to the gate; the shape memory alloy wire is electrically connected to the driving circuit, and when heated by electricity, it contracts to drive the gate to slide.

[0009] Furthermore, it also includes a manual reset mechanism, which includes a lock and a reset slider; the reset slider is linked to the lock and abuts against the gate in the second position when the lock is locked; when the operator opens the lock, the lock drives the reset slider to move, pushing the gate from the second position back to the first position and triggering a reset signal.

[0010] Furthermore, the lock integrates a biometric identification module, which is used to verify the identity of the operator. Successful verification is one of the prerequisites for opening the lock.

[0011] Compared with the prior art, this application has the following beneficial technical effects:

[0012] 1. By integrating the mechanical blocking component and the relay into the same locking part and controlling them both by the same drive circuit, a dual interlocking mechanism of mechanical and electrical linkage is formed, providing a complete physical isolation capability that far exceeds that of single power failure protection, and can effectively resist various persistent attacks or intrusions carried out through data lines.

[0013] 2. A U-shaped nickel-titanium alloy shape memory wire is used as the actuator. The wire, heated by electricity, generates contraction deformation to drive the gate. This structure eliminates the need for complex gears, motors, and other transmission components, resulting in a simple and compact overall design with fewer potential failure points. The operation is noiseless, making it suitable for noise-sensitive industrial environments or those requiring concealed safety protection. It also boasts high reliability and long-term stability.

[0014] 3. By integrating a manual reset mechanism with a reset slider and linking it with the lock, it ensures that after a physical blockage is triggered, only authorized personnel using a dedicated key (which can be combined with biometric verification) can perform the unlocking operation to reset the gate and restore power through mechanical linkage. This design not only prevents unauthorized physical bypass or remote restoration, ensuring the security of the isolated state, but also provides a reliable and controlled physical operation path for the legitimate and necessary restoration of equipment access. Attached Figure Description

[0015] Figure 1 This is a structural framework diagram of industrial internet terminal access devices.

[0016] Figure 2 This is a flowchart of the access process.

[0017] Figure 3 This is a structural diagram of the mechanical blocking component and the manual reset mechanism (connected to the access port).

[0018] Figure 4 This is a structural diagram of the mechanical blocking component and the manual reset mechanism (access port blocking).

[0019] The following is an explanation of the reference numerals in the attached figures:

[0020] 10. Locking unit; 11. Guide groove; 20. Driver; 30. Gate; 40. Lock; 41. Reset slider; 42. Biometric identification module; 50. Access port. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] In the following embodiments, the same or similar reference numerals denote the same or similar components or components with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this utility model, it should be understood that the terms such as center, longitudinal, transverse, length, width, thickness, upper, lower, front, back, left, right, vertical, horizontal, top, bottom, inner, outer, clockwise, and counterclockwise, indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description; therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features shown. In the description of this utility model, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0024] refer to Figure 1 and Figure 2 An industrial internet terminal access device based on device behavior fingerprinting, the device includes an access port 50, a main controller, a behavior fingerprint acquisition module, an analysis and processing module, an access control module, and an interlocking mechanism.

[0025] The behavioral fingerprint acquisition module includes a current sensing unit, an electromagnetic radiation sensing unit, and a timing analysis unit. The current sensing unit connects to the power supply line of port 50 in a non-contact or series manner, sampling the current signal flowing through the access device in real time, with a particular focus on extracting its high-frequency ripple components. Simultaneously, the electromagnetic radiation sensing unit is positioned close to access port 50, typically employing a near-field probe or miniature antenna array, to capture the weak near-field electromagnetic radiation spectrum generated by the access device during power-up and communication. The timing analysis unit works in conjunction with the main controller's network protocol stack or dedicated packet capture hardware to accurately record microsecond-level or even nanosecond-level timestamps of data packet transmission, reception, and response, forming precise time-series data. These three types of data collectively constitute the original behavioral characteristics of the device at the electrical, electromagnetic, and behavioral timing levels.

[0026] The analysis and processing module includes an AI processing unit and a secure storage unit. The multimodal raw data collected by the behavioral fingerprint acquisition module is transmitted to this module. The AI ​​processing unit, typically implemented using an embedded neural network acceleration chip or a high-performance microprocessor, is responsible for running a pre-trained deep learning model. The deep learning model first performs a time-frequency domain transformation on the current ripple signal to extract spectral features, then performs dimensionality reduction and feature filtering on the electromagnetic spectrum data, and performs statistical analysis on the time series to obtain pattern features such as delay and jitter. Subsequently, the model fuses and encodes these heterogeneous features, ultimately generating a multidimensional feature vector. This vector is designed to uniquely characterize the hardware characteristics and inherent operating modes of a specific device.

[0027] The generated feature vectors are used for real-time comparison. Furthermore, during the initial legitimate registration or security learning phase of a device, they can be encrypted and stored in a secure storage unit connected to the analysis and processing module via a secure bus (such as an SPI or I2C bus using an encryption protocol), forming a baseline feature vector library for legitimate devices. The secure storage unit is typically an encryption chip or secure element with physical tamper-proof functionality.

[0028] The access control module is responsible for executing the final authentication and isolation decisions, and includes a decision logic unit and driving circuitry. The decision logic unit receives feature vectors generated by the AI ​​processing unit in real time and compares them with a benchmark library stored in the secure storage unit. The comparison algorithm uses cosine similarity calculation to quantify the degree of matching between the real-time vector and the benchmark vector.

[0029] refer to Figure 3 and Figure 4 The output of the drive circuit is connected to an interlocking mechanism, which is located in the locking part 10 and includes a mechanical blocking component and a relay. A preferred embodiment of the driver 20 uses a U-shaped nickel-titanium alloy shape memory wire. Both ends of the wire are fixed to the locking part 10, and the middle is connected to the gate 30. Under normal conditions (without power), the wire is in a martensitic state and is relatively long, with the gate 30 in the open position. When the drive circuit heats the wire due to a secondary interlock signal, the wire transforms into an austenitic state and undergoes contraction deformation, thereby pulling the gate 30 along the guide groove 11 into the blocking position. This design is simple, noiseless, and reliable.

[0030] The decision logic unit internally stores three decreasing similarity thresholds: a first similarity threshold, a second similarity threshold, and a third similarity threshold. When the calculated cosine similarity is lower than the first threshold but higher than or equal to the second threshold, it indicates a slight abnormality in device behavior, but not a complete mismatch. At this time, the decision logic unit outputs a warning signal to the main controller. If the similarity further decreases to below the second threshold but higher than or equal to the third threshold, it is judged as a moderate risk, and the decision logic unit outputs a first-level interlock signal. This signal drives the drive circuit in the access control module, causing the drive circuit to control the relay in the interlock mechanism to operate, disconnecting the switch contacts connected in series in the power circuit of access port 50, thereby cutting off the power supply to the suspected illegal device. When the similarity falls below the lowest third threshold, it means that the behavioral fingerprint is seriously mismatched, and the decision logic unit outputs a second-level interlock signal. At this time, the drive circuit will simultaneously drive the relay in the interlock mechanism to disconnect the power circuit and drive the mechanical blocking component to operate.

[0031] The mechanical blocking component specifically includes a gate 30 driven by a driver 20 (such as a micro motor or a specific actuator). This gate 30 is slidably mounted in a guide groove 11 of a specially designed locking part 10 within the device housing. Upon receiving a secondary interlock signal, the driver 20 pushes the gate 30 into the physical slot channel of the access port 50, physically blocking the insertion of any connector or contact of data pins in connected links, achieving complete data channel isolation. This dual physical isolation mechanism of relay de-energization and mechanical gate 30 blocking constitutes a robust barrier against high-level threats.

[0032] To further enhance security response capabilities, the device also integrates a decoy analysis sandbox. When the decision logic unit outputs a warning signal, the main controller does not immediately perform physical isolation but instead activates the sandbox mechanism. Network traffic from suspected unauthorized devices is redirected to the decoy analysis sandbox. The decoy analysis sandbox includes a virtual port simulator, isolated security domain memory, and a separate security processor. The virtual port simulator simulates a real industrial protocol port, the isolated security domain memory securely runs a simulated industrial protocol stack (such as a simulated Modbus TCP or PROFINET stack), and the security processor executes this simulated protocol stack. The security processor injects test command sequences into suspected devices, observes and records their response behavior.

[0033] These response behavior data are fed back to the analysis and processing module, which can be used in two ways: first, if a variant of a new legitimate device is found, the baseline feature vector library can be updated accordingly to enhance the system's adaptability; second, attack patterns can be analyzed to adaptively adjust the similarity threshold parameters of the decision logic unit in order to optimize the recognition accuracy.

[0034] For certified legitimate devices, the device also possesses the capability for invisible identification implantation. This function is implemented by an invisible identification implantation module, the core of which is a programmable ripple generation circuit. After the device is certified as legitimate, the main controller instructs this circuit to superimpose a weak AC ripple signal, specifically encoded (such as FSK or PSK modulation based on the device ID), onto the power circuit of access port 50. The amplitude of this identification ripple signal is precisely controlled to a level that neither affects the normal operation of the connected device nor fails to be reliably detected by the device's current sensing unit. This is equivalent to adding an invisible "electronic watermark" to the legitimate connection, facilitating rapid identity reconfirmation during subsequent continuous monitoring and preventing the device from being "switched" after connection.

[0035] To ensure recoverability in case of emergencies or system failures, the locking unit 10 is equipped with a manual reset mechanism. This mechanism includes a lock 40 and a reset slider 41 linked to the lock 40. When the access port 50 is in the blocked state, the reset slider 41 is pressed against the gate 30 by a spring. Authorized operators need to use a special key to open the lock 40. The unlocking action will move the reset slider 41 through mechanical linkage, pushing the gate 30 from the blocked position back to the open position. At the same time, this process will trigger a reset signal switch, which is sent to the main controller. The main controller will then control the drive circuit to stop outputting the power-off signal, reset the relay, and thus fully restore the power supply and connection function of the port.

[0036] To enhance the security of manual reset operations, the lock 40 may further integrate a biometric identification module 42 (such as a fingerprint reader). With this configuration, the unlocking operation must meet both the "insertion of a dedicated key" and "passing of biometric verification," ensuring that only authorized personnel can perform the reset and preventing unauthorized physical bypass.

[0037] The scope of protection of this utility model includes, but is not limited to, the above embodiments. The scope of protection of this utility model is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art shall fall within the scope of protection of this utility model.

Claims

1. An interlocking mechanism for a terminal access device, disposed within a locking portion (10) of the housing of the terminal access device, characterized in that, include: Drive circuit; A mechanical blocking component, wherein the driving end of the mechanical blocking component is connected to the output end of the driving circuit, and the execution end of the mechanical blocking component is located at the access port (50) of the terminal access device, for making linear motion under the control of the driving circuit, physically blocking or opening the access port (50). A relay, the coil of which is connected to the output terminal of the drive circuit, and the switch contacts of which are connected in series in the power supply circuit of the access port (50).

2. The interlocking mechanism according to claim 1, characterized in that, The mechanical blocking assembly includes a driver (20) and a gate (30); a guide groove (11) is provided in the locking part (10), and the gate (30) is slidably assembled in the guide groove (11); the driver (20) is connected to the gate (30) and is used to drive the gate (30) to slide along the guide groove (11); when the gate (30) slides to the first position, the access port (50) is opened; when the gate (30) slides to the second position, the access port (50) is physically blocked.

3. The interlocking mechanism according to claim 2, characterized in that, The actuator (20) is a U-shaped nickel-titanium alloy shape memory alloy wire. The two ends of the shape memory alloy wire are fixed to the locking part (10), and the middle part is connected to the gate (30). The shape memory alloy wire is electrically connected to the driving circuit. When it is heated by electricity, it contracts to drive the gate (30) to slide.

4. The interlocking mechanism according to claim 2 or 3, characterized in that, It also includes a manual reset mechanism, which includes a lock (40) and a reset slider (41); the reset slider (41) is linked to the lock (40) and abuts against the gate (30) in the second position when the lock (40) is in the locked state; when the operator opens the lock (40), the lock (40) drives the reset slider (41) to move, pushes the gate (30) from the second position back to the first position, and triggers a reset signal.

5. The interlocking mechanism according to claim 4, characterized in that, The lock (40) is equipped with a biometric identification module (42), which is used to verify the identity of the operator. Successful verification is one of the prerequisites for opening the lock (40).

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