Mutual redundancy control method and system for electric transmission devices of tension roller set

Abstract

The invention belongs to the field of industrial automation control, and particularly relates to a mutual redundancy control method and system for tension roller set electric transmission devices. The mutual redundancy control method for the electric transmission devices of the tension roller set is specifically applied to a production line system where the tension roller set is located and comprises the following steps that S1, when it is detected that an Nth roller of the tension roller set production line system breaks down, a fault switching button corresponding to the Nth tension roller is triggered; s2, the PLC system receives the fault switching signal and then executes a redundancy control program, and a control signal and operation signal loop associated with the Nth roller is disconnected; and the operation signal of the transmission device of the normal roller adjacent to the Nth roller is used for replacing the operation signal of the Nth roller and is fed back to the PLC system, so that the continuous operation of the tension roller group is maintained. The method and the system are high in reliability and stability, and continuous operation of the production line can be guaranteed.

Description

Technical Field

[0001] The present invention belongs to the field of industrial automation control, and particularly relates to a redundant control method and system for an electrical drive device of a tension roll group. Background Art

[0002] In the field of industrial automation, the tension roll group, as a core device of the strip continuous production line, is widely used in key process links such as cold tandem rolling, continuous annealing, galvanizing, recoiling, and color coating. Its core function is to ensure the smooth conveying and processing quality of materials during production by precisely adjusting the strip tension. The electrical drive device and the drive motor, as the power source of the tension roll group, directly determine the operating stability of the system. However, in the prior art, the electrical drive system of the tension roll group has significant defects in dealing with sudden failures, which seriously restricts the production efficiency and continuity.

[0003] Currently, the tension roll group control schemes commonly adopted in the industry mainly rely on a single electrical drive device to drive each roll group, lacking an effective redundancy mechanism. When a certain drive device or motor fails (such as overload, short circuit, or communication interruption), the system usually needs to be completely shut down, and manual intervention is required to troubleshoot the fault and replace the equipment. This process takes a long time. Especially in large continuous production lines, downtime for maintenance may lead to production interruptions for several hours or even longer, causing huge economic losses. In addition, the redundancy schemes in the prior art mostly adopt hardware backup forms (such as dual-motor configuration). Although it can shorten the fault response time, it still requires complex switching logic and manual intervention, and the cost is high.

[0004] Patent (CN202110559294) adopts a main and standby dual-motor configuration and controls the switching logic through a PLC program. When the main motor fails, the standby motor starts and takes over the work. However, the switching logic of this patent is fixed and depends on the preset PLC program. It cannot dynamically adjust the substitution priority according to the multi-roll group fault scenario (for example, it cannot automatically select the optimal adjacent roll signal), the signal delay is high, and the switching between the main and standby motors requires multiple levels of signal transmission (such as status sampling, digital-to-analog conversion), resulting in switching delay and easy to cause tension fluctuations. Patent (CN 113467224 B) discloses a redundant device switching system based on software logic. By continuously transmitting working signals between the main and standby devices, the standby device is enabled when the main device is abnormal. Although this scheme reduces the hardware dependence, it has the following deficiencies: dependence on manual intervention: after the main device is repaired, it needs to be manually restarted, prolonging the downtime; lack of coordinated control: the switching logic is only designed for a single device and does not involve a multi-roll group cascading substitution mechanism. Most of the existing redundancy schemes in the prior art are designed for a single device and lack a multi-roll group cascading substitution logic. When multiple roll groups fail simultaneously, the system cannot maintain operation through the dynamic signal substitution of adjacent roll groups, resulting in a complete paralysis of the production line.

[0005] In view of the above problems, there is an urgent need for an efficient and low-cost redundancy control method that can quickly switch to a backup signal source when the electric drive device fails, minimize the downtime to the greatest extent, and ensure the stability of the tension parameters, providing a reliable guarantee for the continuous operation of the industrial production line. Summary of the Invention In view of this, in order to solve the above problems, the present invention discloses a mutually redundant control system and method for the electric drive device of a tension roller group. The technical solutions adopted by the present invention are as follows: In the first aspect of the present invention, a mutually redundant control method for the electric drive device of a tension roller group is disclosed. In the production line system where the tension roller group is located, an HMI is provided, and multiple fault switching buttons are set on the interface of the HMI, respectively corresponding independently to multiple tension rollers of the tension roller group; in the production line system where the tension roller group is located, a PLC system is provided, and a redundancy control program is set in the PLC system, including the following steps: S1. When it is detected that the Nth roller of the production line system fails, trigger the fault switching button corresponding to the Nth tension roller to release a fault switching signal. S2. After the PLC system receives the fault switching signal, execute the redundancy control program, so that the PLC system disconnects the control signal and operation signal circuits associated with the Nth roller; and replace the operation signal of the Nth roller with the operation signal of the normal roller adjacent to the Nth roller, and feedback it to the PLC system, and maintain the continuous operation of the tension roller group based on the replaced signal.

[0006] In some embodiments, the selection rule for the normal roller adjacent to the Nth roller is as follows: When the Nth roller fails, preferably select the operation signal of the (N + 1)th roller for replacement; if the (N + 1)th roller is unavailable, select the (N - 1)th roller.

[0007] In some embodiments, the S2 step further includes a fault recovery detection step: When the Nth roller returns to normal, automatically switch back to the original control mode and restore its control signal and operation signal circuits.

[0008] In some embodiments, it includes the following modules: HMI, PLC system, and tension roller group drive module, and the PLC system includes a PLC control unit; The HMI is provided with multiple independent fault switching buttons, and each button corresponds to a fault status identifier of a tension roller, which is used to control the PLC control unit and is connected to the PLC control unit through electrical connection or bus protocol transmission; The PLC control unit has a built-in redundant control program, and the redundant control program is used to control the transmission device. After the PLC control unit receives the fault switching signal of the fault switching button, the following operations are performed: disconnect the control signal and operation signal circuits of the faulty roll; use the operation signal of the adjacent roll's transmission device to replace the faulty roll signal through signal replacement logic and feedback it to the PLC control unit; The tension roll group drive module includes a tension roll group drive device, and the tension roll group drive device is connected to the PLC control unit through electrical connection or bus protocol transmission for receiving control instructions and feedbacking operation signals.

[0009] In some embodiments, the fault switching button is connected to the signal transmission module through hard wiring or a digital communication interface, and the trigger signal of each fault switching button is transmitted to the PLC control unit after being encoded by the signal transmission module.

[0010] In some embodiments, the PLC control unit includes: a signal gating logic unit, which is connected to the tension roll group drive module through hard wiring, generates a cut-off instruction for the faulty roll signal circuit according to the fault switching instruction of the redundant control program, and cuts off the connection of the tension roll group drive module; A signal replacement logic unit, which is connected to the tension roll group drive device through an EtherCAT bus, is dynamically called by the redundant control program, obtains the operation signal of the adjacent roll and generates a replacement instruction through an algorithm to overwrite the fault signal logic.

[0011] In some embodiments, the replacement priority in the signal replacement logic unit is: when the Nth roll fails, the operation signal of the (N + 1)th roll is preferentially selected; if the (N + 1)th roll is unavailable, the signal of the (N - 1)th roll is selected; The tension roll group drive device also includes I / O ports and bus communication; The replacement instruction is sent to the PLC control unit through the I / O ports and bus communication.

[0012] In some embodiments, the tension roll group drive module further includes a real-time data acquisition module, and the PLC system is connected to the tension roll group drive device through the real-time data acquisition module for dynamically adjusting the parameters of the tension roll group.

[0013] In some embodiments, the PLC control unit further includes: A fault status self-check unit, which is connected to the tension roll group drive device through a diagnostic bus and is used to continuously monitor the recovery status of the faulty roll; An automatic switching unit, which is linked with the signal gating logic unit and the signal replacement logic unit to re-establish the original signal circuit after the fault is recovered.

[0014] In some embodiments, the HMI integrates the following connection components: a visual fault indication module for real-time display of the faulty roll number, alternative signal source, and tension parameters; an alarm output interface, which is a dry contact relay interface and is hard-wired to an external audible and visual alarm device.

[0015] The beneficial effects of the present invention at least include: When any one of the electric drive devices, motors, or other auxiliary equipment in the tension roll group fails, the operating signal source fed back by the adjacent control roll drive device is used to replace the operating signal source of the faulty equipment and fed back to the PLC control system, quickly cutting off the faulty signal loop, achieving the purpose of mutual redundancy control, ensuring the continuous operation of the tension roll group, thus avoiding production interruption, improving the reliability and stability of the system, and being of great significance for ensuring the continuous operation of the production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other embodiments can be obtained based on these drawings.

[0017] Figure 1 The flowchart of the mutual redundancy control method for the electric drive device of the tension roll group of the present invention is shown; Figure 2 The control diagram of the electric drive device of the tension roll group before the implementation of the present invention; Figure 3 The redundancy control system of the electric drive device of the tension roll group in some embodiments of the present invention.

[0018] DESCRIPTION OF THE REFERENCE NUMERALS 1, HMI; 101, fault switching button; 2, PLC system; 201, PLC control unit; 3, tension roll group drive module; 301, tension roll group drive device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the embodiments of the present invention in detail with reference to specific embodiments and the accompanying drawings.

[0020] It should be noted that all the expressions using "first" and "second" in the embodiments of the present invention are used to distinguish two entities or parameters with the same name but different identities. It can be seen that "first" and "second" are only for the convenience of expression and should not be construed as a limitation on the embodiments of the present invention. This will not be elaborated in the subsequent embodiments one by one.

[0021] In the present invention, "a plurality of" means one or more.

[0022] In the present invention, HMI (Human Machine Interface) refers to the human-machine interface; it is the interface for information exchange between humans and machines. Through the HMI, operators can monitor the status of the machine, input commands to control the behavior of the machine, adjust setting parameters, etc. It is usually a touch-screen display installed beside the production line or in the control room, used to display system status, alarm information, and allow operators to make necessary control inputs.

[0023] Before the implementation of the present invention, the control diagram of the electrical drive device of the pre-tensioning roller group is as Figure 2 shown. To cope with possible fault situations and ensure the continuous operation of the tensioning roller group, thus avoiding production interruption, the redundant design of the present invention improves the reliability and stability of the system. It is of great significance for ensuring the continuous operation of the production line.

[0024] On the one hand, the present invention discloses a mutual redundancy control method for the electrical drive device of the tensioning roller group. As Figure 1 shown, in the production line system where the tensioning roller group is located, there is an HMI1, and a plurality of fault switching buttons 101 are set on the interface of the HMI1, respectively corresponding independently to a plurality of tensioning rollers of the tensioning roller group; in the production line system where the tensioning roller group is located, there is a PLC system 2, and a redundant control program is set in the PLC system 2, including the following steps: S1. When it is detected that the Nth roller of the production line system fails, trigger the fault switching button 101 corresponding to the Nth tensioning roller to release a fault switching signal; S2. After the PLC system 2 receives the fault switching signal, execute the redundant control program, so that the PLC system 2 disconnects the control signal and operation signal circuits associated with the Nth roller; and replace the operation signal of the Nth roller with the operation signal of the transmission device of the normal roller adjacent to the Nth roller, and feedback it to the PLC system 2, and maintain the continuous operation of the tensioning roller group based on the replaced signal.

[0025] The method of the present invention is applied to the electrical drive device of the tensioning roller group. When a certain electrical drive device in the system fails, the redundant electrical drive device can immediately take over the work to ensure the continuous operation of the tensioning roller group, thus avoiding production interruption. The present invention improves the reliability and stability of the system through this redundant design. It is of great significance for ensuring the continuous operation of the production line. Specifically, in some embodiments, the present invention quickly triggers fault switching through the HMI1 interface and combines with the PLC redundant program to achieve millisecond-level fault isolation, reducing the downtime by at least 30%; In the present invention, N of the Nth roller is an integer greater than or equal to 1, that is, the first or the Nth roller; The triggering described in the present invention can be automatic triggering or manual triggering. When the PLC control system automatically detects a fault in the Nth roller, or the operator clicks the corresponding fault switching button 101 on the HMI1 interface, a fault switching signal is triggered.

[0026] In order to clarify the adjacent roller replacement rule, in some embodiments, the selection rule for the normal roller adjacent to the Nth roller is as follows: When the Nth roller fails, the operating signal of the (N + 1)th roller is preferentially selected for replacement; if the (N + 1)th roller is unavailable, the (N - 1)th roller is selected. When the transmission operating signal of the (N + 1)th roller is lost or it is detected to be in a fault state, it is determined to be unavailable. The switching rule of the present invention can shorten the switching path, reduce the signal transmission delay, and avoid mis-switching to abnormal equipment through the "unavailable" state determination (signal loss or fault detection), thereby improving the redundancy reliability.

[0027] During the production process, the S2 step further includes a fault recovery detection step: After the Nth roller returns to normal, it automatically switches back to the original control mode, and its control signal and operating signal circuits are restored. In some embodiments, the basis for determining whether the Nth roller has returned to normal or failed is confirmed by the PLC control system through the current feedback signal of the tension roller group. After the PLC control system confirms that the Nth roller has returned to normal, it automatically switches back to the original control mode, and its control signal and operating signal circuits are restored. Some embodiments of the present invention automatically detect the equipment recovery status based on the current feedback signal, which can reduce the manual inspection cost and seamlessly switch back to the original control mode, avoiding the risk of secondary shutdown caused by manual operation.

[0028] The second aspect of the present invention discloses a redundant control system for an electrical drive device of a tension roller group, as Figure 3 shown, including the following modules: HMI1, PLC system 2, and tension roller group drive module 3, and the PLC system 2 includes a PLC control unit 201; The HMI1 is provided with a plurality of independent fault switching buttons 101, and each button corresponds to a fault status identifier of a tension roller, and is used to control the PLC control unit 201 and is connected to the PLC control unit 201 through electrical connection or bus protocol transmission; The PLC control unit 201 has a built-in redundant control program, which is used to control the transmission device. After the PLC control unit 201 receives the fault switching signal of the fault switching button 101, the following operations are performed: disconnect the control signal and operation signal circuits of the faulty roll; replace the signal of the faulty roll with the operation signal of the transmission device of the adjacent roll through signal substitution logic, and feedback it to the PLC control unit 201; The tension roll group drive module 3 includes a tension roll group drive device 301, which is connected to the PLC control unit 201 through electrical connection or bus protocol transmission, and is used to receive control instructions and feedback operation signals.

[0029] The modular design (HMI1, PLC system 2, tension roll group drive module 3) of the system of the present invention can simplify the system architecture and reduce the complexity of installation and maintenance.

[0030] In some embodiments, the group of fault switching buttons 101 in the HMI1 is connected to the signal transmission module through hard wiring or a digital communication interface, and the trigger signal of each fault switching button 101 is transmitted to the PLC control unit 201 after being encoded by the signal transmission module. In the present invention, the use of hard wiring and digital communication interfaces (such as Modbus) can ensure the high-reliability transmission of key signals; the signal coding conversion (such as Modbus RTU to TCP) can enhance protocol compatibility and support the integration of multi-brand devices.

[0031] In some embodiments, the PLC control unit 201 includes: a signal gating logic unit, which is connected to the tension roll group drive module 3 through hard wiring, generates a cut-off instruction for the faulty roll signal circuit according to the fault switching instruction of the redundant control program, and cuts off the connection of the tension roll group drive module 3; A signal substitution logic unit, which is connected to the tension roll group drive device 301 through an EtherCAT bus, is dynamically called by the redundant control program, obtains the operation signal of the adjacent roll, and generates a substitution instruction through an algorithm to cover the faulty signal logic. Among them, the redundant control program coordinates the timing actions of the two logic units, first performs a hard cut-off, and then completes a soft substitution to ensure a disturbance-free redundant switching process. The invention selects hard wiring to connect the signal gating logic unit, which can achieve physical isolation of the faulty signal circuit, and the EtherCAT bus supports microsecond-level signal synchronization to ensure accurate matching of the tension parameters of the substitution signal and the original signal.

[0032] In some embodiments, the substitution priority in the signal substitution logic unit (that is, the substitution priority of the normal roll adjacent to the Nth roll in the signal substitution logic unit) is: when the Nth roll fails, the operation signal of the (N + 1)th roll is preferentially selected; if the (N + 1)th roll is unavailable, the signal of the (N - 1)th roll is selected; The tension roll group drive device 301 further includes an I / O port and bus communication; The replacement instruction is sent to the PLC control unit 201 through the I / O port and bus communication.

[0033] The present invention sends replacement instructions through a dual-path of I / O port and bus communication, improving the system fault tolerance.

[0034] In some embodiments, the tension roll group drive module 3 further includes a real-time data acquisition module. The PLC system 2 is connected to the tension roll group drive device 301 through the real-time data acquisition module and is used to dynamically adjust the parameters of the tension roll group. The adjustment includes: a smooth transition algorithm for the tension value; rate synchronization control of the replacement signal and the original signal of the faulty roll; the smooth transition algorithm for the tension value adopts a PID control algorithm; the rate synchronization of the replacement signal and the original signal of the faulty roll is achieved through the EtherCAT distributed clock protocol. The PID algorithm realizes the smooth transition of the tension value, avoids sudden changes in tension during switching, and ensures the quality of strip processing; The EtherCAT distributed clock protocol ensures strict synchronization of the rates of the replacement signal and the original signal, reducing mechanical wear.

[0035] In some embodiments, the PLC control unit 201 further includes: A fault status self-check unit, which is connected to the tension roll group drive device 301 through a diagnostic bus and is used to continuously monitor the recovery status of the faulty roll; An automatic switching unit, which is linked with the signal gating logic unit and the signal replacement logic unit, and re-establishes the original signal loop after the fault is recovered. The diagnostic bus monitors the fault recovery status in real time, reducing the manual confirmation time; The automatic switching unit of the present invention is linked with the signal logic to ensure the timing consistency of the reconstruction of the original signal loop and prevent signal conflicts.

[0036] In some embodiments, the HMI1 integrates the following connection components: The HMI1 integrates the following connection components: a visual fault indication module, which is used to display the faulty roll number, replacement signal source, and tension parameters in real time; an alarm output interface, and the alarm output interface is a dry contact relay interface, which is hard-wired to an external audible and visual alarm device. The visual interface of the present invention displays the fault number, replacement signal source, and tension parameters in real time, improving the decision-making efficiency of operators; the dry contact relay interface of the present invention supports compatibility with various external alarm devices, simplifying the system integration cost.

[0037] The solution of the present invention will be explained below in conjunction with embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. For those embodiments where specific techniques or conditions are not indicated, the conventional technical solutions in the art are adopted. For the instruments whose manufacturers are not indicated, they are all conventional products that can be obtained through commercial purchase.

[0038] As Figure 3 shown, the specific implementation of the redundant control method for the electrical drive device of the tension roller group of the present invention is as follows: 1. When the 1# roller in the tension roller drive module 3 fails, select the 1# roller fault switching button 101 on the HMI1. After the PLC control unit 201 in the PLC system 2 receives the 1# roller fault selection, through the gating control of the redundant control program, disconnect the control signal sent by the PLC system 2 to the 1# roller drive device in the 1# tension roller group drive module 3, and disconnect the operation signal fed back from the 1# roller drive device to the PLC system 2. At the same time, use the operation signal fed back from the 2# roller drive device in the 2# tension roller group drive module 3 to replace the operation signal of the 1# roller drive device in the 1# tension roller group drive module 3 and send it to the PLC system 2. In this way, it can be realized that the 1# roller has returned to normal operation in the control system, and the production of the unit can be quickly restored.

[0039] 2. When the 2# roller in the tension roller drive module 3 fails, select the 2# roller fault switching button 101 on the HMI1. After the PLC control unit 201 in the PLC system 2 receives the 2# roller fault selection, through the gating control of the redundant control program, disconnect the control signal sent by the PLC system 2 to the 2# roller drive device in the 2# tension roller group drive module 3, and disconnect the operation signal fed back from the 2# roller drive device to the PLC system 2. At the same time, use the operation signal fed back from the 1# roller drive device in the 1# tension roller group drive module 3 to replace the operation signal of the 2# roller drive device in the 2# tension roller group drive module 3 and send it to the PLC system 2. In this way, it can be realized that the 2# roller has returned to normal operation in the control system, and the production of the unit can be quickly restored.

[0040] 3. When the 3# roller in the tension roller drive module 3 fails, select the 3# roller fault switching button 101 on the HMI1. After the PLC control unit 201 in the PLC system 2 receives the 3# roller fault selection, through the gating control of the redundant control program, disconnect the control signal sent by the PLC system 2 to the 3# roller drive device in the 3# tension roller group drive module 3, and disconnect the operation signal fed back from the 3# roller drive device to the PLC system 2. At the same time, use the operation signal fed back from the 4# roller drive device in the 4# tension roller group drive module 3 to replace the operation signal of the 3# roller drive device in the 3# tension roller group drive module 3 and send it to the PLC system 2. In this way, it can be realized that the 3# roller has returned to normal operation in the control system, and the production of the unit can be quickly restored.

[0041] 4. When the 4# roller in the tension roller drive module 3 fails, select the 4# roller fault switching button 101 on the HMI 1. After the PLC control unit 201 in the PLC system 2 receives the 4# roller fault selection, through the gating control of the redundant control program, disconnect the control signal sent by the PLC system 2 to the 4# roller drive device in the 4# tension roller group drive module 3, and disconnect the operation signal fed back by the 4# roller drive device to the PLC system 2. At the same time, replace the operation signal of the 4# roller drive device in the 4# tension roller group drive module 3 with the operation signal fed back by the 3# roller drive device in the 3# tension roller group drive module 3 and send it to the PLC system 2. In this way, it can be realized that the 4# roller has resumed normal operation in the control system, and the production of the unit can be quickly resumed.

[0042] Through the production line test, the system fault switching time of the present invention is ≤ 50 ms, the downtime is reduced by 35%, and the qualified rate of strip processing is increased to 99.2%.

[0043] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0044] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for redundant control of electrical transmission devices of tension roller groups, characterized in that: A production line system where a tension roller group is located is provided with an HMI (1), and an interface of the HMI (1) is provided with a plurality of fault switching buttons (101), each independently corresponding to a plurality of tension rollers of the tension roller group; a production line system where the tension roller group is located is provided with a PLC system (2), and a redundant control program is provided in the PLC system (2), comprising the following steps: S1. When a failure of the Nth roller of the production line system is detected, the fault switching button (101) corresponding to the Nth tension roller is triggered to release a fault switching signal; S2. After receiving the fault switching signal, the PLC system (2) executes the redundant control program, so that the PLC system (2) disconnects the control signal and operation signal loop associated with the Nth roller; and replaces the operation signal of the Nth roller with the transmission device operation signal of the normal roller adjacent to the Nth roller, and feeds it back to the PLC system (2), so as to maintain the continuous operation of the tension roller group based on the replaced signal.

2. The method according to claim 1, characterized in that The selection rule of the normal roller adjacent to the Nth roller is: When roller No. N fails, the operating signal of roller No. N+1 is preferentially selected as a replacement; if roller No. N+1 is unavailable, roller No. N-1 is selected.

3. The method according to claim 1, characterized in that The S2 step also includes a fault recovery detection step: When the Nth roller returns to normal, it automatically switches back to the original control mode and restores its control signal and operation signal circuit.

4. A redundant control system for an electrical transmission device of a tension roller group, characterized in that: The invention comprises the following modules: an HMI (1), a PLC system (2) and a tension roller group transmission module (3), wherein the PLC system (2) comprises a PLC control unit (201); The HMI (1) is provided with a plurality of independent fault switching buttons (101), each button corresponding to a fault status mark of a tension roller, and used for controlling the PLC control unit (201), and connected to the PLC control unit (201) via electrical connection or bus protocol transmission; The PLC control unit (201) has a built-in redundant control program, and the redundant control program is used to control the transmission device. When the PLC control unit (201) receives a fault switching signal from a fault switching button (101), the following operations are performed: disconnecting the control signal and operation signal loop of the faulty roller; replacing the faulty roller signal with the transmission device operation signal of the adjacent roller through signal replacement logic, and feeding back the signal to the PLC control unit (201); The tension roller group transmission module (3) comprises a tension roller group transmission device (301), and the tension roller group transmission device (301) is connected to the PLC control unit (201) via electrical connection or bus protocol transmission, and is used to receive control instructions and feed back operating signals.

5. The system according to claim 4, characterized in that The fault switching button (101) is connected to the signal transmission module via hard wiring or a digital communication interface, and the trigger signal of each fault switching button (101) is encoded by the signal transmission module and then transmitted to the PLC control unit (201).

6. The system according to claim 4, characterized in that The PLC control unit (201) comprises: a signal gating logic unit, which is connected to the tension roller group transmission module (3) via hard wiring, and generates a disconnection instruction for the fault roller signal circuit according to the fault switching instruction of the redundant control program, thereby disconnecting the connection of the tension roller group transmission module (3); The signal replacement logic unit is connected to the tension roller group transmission device (301) via the EtherCAT bus, is dynamically called by the redundant control program, obtains the adjacent roller operation signal and generates a replacement instruction through an algorithm to cover the fault signal logic.

7. The system according to claim 6, characterized in that The substitution priority in the signal substitution logic unit is: when the Nth roller fails, the operation signal of the N+1th roller is selected first; if the N+1th roller is unavailable, the signal of the N-1th roller is selected; The tension roller group transmission device (301) also includes an I / O port and bus communication; The replacement instruction is sent to the PLC control unit (201) via the I / O port and bus communication.

8. The system according to claim 4, characterized in that The tension roller group transmission module (3) further comprises a real-time data acquisition module, and the PLC system (2) is connected to the tension roller group transmission device (301) via the real-time data acquisition module, and is used to dynamically adjust the parameters of the tension roller group.

9. The system according to claim 4, characterized in that The PLC control unit (201) further includes: A fault state self-checking unit, the fault state self-checking unit being connected to the tension roller group transmission device (301) via a diagnostic bus and being used for continuously monitoring the recovery state of the faulty roller; The automatic switching unit is linked with the signal selection logic unit and the signal substitution logic unit to re-establish the original signal loop after the fault is restored.

10. The system according to any one of claims 4 to 9, characterized in that: The HMI (1) integrates the following connection components: a visual fault indication module for real-time display of the fault roller number, alternative signal source and tension parameter; an alarm output interface, wherein the alarm output interface is a dry contact relay interface and is hard-wired to an external sound and light alarm device.

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