A brake system and method

Abstract

Provided are a brake system and method, the brake system comprising an anomaly detection component, a backup control component, and a backup power supply component, wherein the anomaly detection component is configured to detect whether a power failure anomaly occurs in a double belt transmission system; the backup control component is in communication connection with the anomaly detection component and is configured to, when receiving a power failure anomaly signal, start a preset brake control algorithm and execute the following steps: based on a state parameter of a driving wheel and a state parameter of a driven wheel when the power failure anomaly occurs, generating a control signal to control a first driving motor to brake at a first brake torque and a second driving motor to brake at a second brake torque, so as to keep the tension of a load within a safe range; the backup power supply component is in electrical connection with the backup control component and is configured to supply power to the backup control component. The brake system provided in the application can safely stop the double belt transmission system when a power failure anomaly occurs in the double belt transmission system, and ensure that the tension of the load is within a safe range.

Description

Technical Field

[0001] This application relates to the field of storage technology, and in particular to a braking system and method. Background Technology

[0002] Due to their low cost and high capacity, magnetic tape storage systems remain widely used in long-term archiving. In recent years, with advancements in multimedia and network technologies, the market urgently needs low-cost storage and recording of large amounts of digital information such as images, audio, and video. Compared to other storage media (such as HDDs), magnetic tape storage offers lower costs, larger storage capacity, and long-term storage capabilities, leading to a rapid increase in market demand.

[0003] The dual-reel delivery system (also known as the dual-reel transport system, or simply the dual-reel system) of a magnetic tape storage system is a crucial subsystem in the magnetic tape reading and writing process, and its performance directly impacts the accuracy and reliability of data reading and writing at the magnetic head. As magnetic tape storage density continues to increase, one approach is to improve the head-following servo system by continuously reducing the width of each data track, allowing more data tracks to be written within the same tape width. Another approach is to reduce the thickness of the magnetic tape medium (currently, commercially available magnetic tape medium is only 5.2 micrometers thick), thereby increasing the total length of the tape within the same volume. Against this backdrop, magnetic tape systems place increasingly stringent demands on high-precision servo systems. Simultaneously, the micrometer-level thickness of the magnetic tape medium poses a significant challenge to the safety and reliability of the entire reel system. Under normal operating conditions (including acceleration, constant speed, and deceleration), a comprehensive monitoring system updates the system status in real time, while the control algorithm adjusts the output torque of the two reel motors in real time based on feedback information, ensuring system reliability. However, the reliable braking of the magnetic tape storage system is tested in the event of an unexpected power outage. During the emergency braking process, the magnetic tape must not break or loosen, and the system must be able to continue to work normally after the power is restored. Summary of the Invention

[0004] Embodiments of this application provide a braking system and method that can safely stop the dual-belt transmission system when an abnormality occurs, ensuring that the load tension remains within a safe range.

[0005] In a first aspect, this application provides a braking system for braking a dual-belt transmission system. The dual-belt transmission system includes a driving pulley and a driven pulley, a first drive motor for driving the driving pulley to rotate, and a second motor for driving the driven pulley to rotate. The driving pulley and the driven pulley have loads. The braking system provided by this application includes an anomaly detection component, a backup control component, and a backup power supply component. The anomaly detection component is used to detect whether an anomaly has occurred in the dual-belt transmission system. The backup control component is communicatively connected to the anomaly detection component and is used to activate a preset braking control algorithm when an anomaly signal is received, and execute the following steps: based on the state parameters of the driving pulley and the driven pulley at the time of the anomaly, a control signal is generated to control the first drive motor to brake with a first braking torque and the second drive motor to brake with a second braking torque, so that the tension of the load is kept within a safe range.

[0006] The braking system provided in this application detects whether an anomaly occurs in the dual-shaft transmission system through an anomaly detection component. When an anomaly is detected, a backup control component is immediately activated. The backup control component activates a preset safety braking control algorithm, which controls the braking torque of the two drive motors based on the state parameters of the driving wheel and the driven wheel at the time of the anomaly. Through the cooperation of the two drive motors, the dual-shaft transmission system is safely stopped, ensuring that the load tension remains within a safe range, that is, the load does not break or loosen, and the system can continue to work normally after the power supply is restored.

[0007] In one possible implementation, the dual-reel conveyor system further includes a main control component, comprising a first MOS bridge and a second MOS bridge, the first MOS bridge being electrically connected to a first drive motor and the second MOS bridge being electrically connected to a second drive motor; anomalies include power failure anomalies; a backup control component includes a backup microcontroller unit (MCU), a backup drive unit, and a backup power supply component, wherein the backup MCU is communicatively connected to the anomaly detection component and is used to generate a control signal based on the state parameters of the drive wheel and the driven wheel when a power failure anomaly signal is received; the backup drive unit is communicatively connected to the backup MCU and electrically connected to the first MOS bridge and the second MOS bridge respectively, and is used to generate a first pulse width modulation (PWM) based on the control signal. The signal is a modulation (PWM) signal and a second PWM signal. The first PWM signal is used to control the on / off ratio of the first MOS bridge to control the first drive motor to perform short-circuit braking with the first braking torque. The second PWM signal is used to control the on / off ratio of the second MOS bridge to control the second drive motor to perform short-circuit braking with the second braking torque. The backup power supply component is electrically connected to the backup microcontroller unit and the backup drive unit respectively, and is used to supply power to the backup microcontroller unit and the backup drive unit in the event of a power failure.

[0008] In this possible implementation, the braking torque for short-circuiting braking of the two drive motors is achieved by controlling the on / off ratio of the MOS bridges (also known as MOS switches) corresponding to the two drive motors respectively. The control of the MOS switches is an extremely low-power operation. Thus, the safe braking of the dual-reel conveyor system can be achieved through extremely low-power operation, reducing the power consumption of the backup power supply components.

[0009] Optionally, considering that the backup power supply unit usually has limited power, in order to reduce the power consumption of the power supply unit, the backup MCU adopts an ultra-low power MCU.

[0010] In another possible implementation, the control signals include a first duty cycle signal and a second duty cycle signal; the backup drive unit includes a first drive circuit and a second drive circuit. The first drive circuit generates a first PWM signal based on the first duty cycle signal, and the second drive circuit generates a second PWM signal based on the second duty cycle signal. That is, the short-circuit braking torque of the two drive motors is controlled by controlling the duty cycle signals of the two drive motors. The duty cycle signal generation is simple, reducing computational overhead and thus power consumption.

[0011] In another possible implementation, the state parameters of the driving wheel include the rotational inertia parameters of the driving wheel, and the state parameters of the driven wheel include the rotational inertia parameters of the driven wheel; the backup microcontroller unit is used to generate a control signal based on the ratio of the rotational inertia parameters of the driving wheel and the driven wheel.

[0012] By adaptively adjusting the control signals for the two drive motors based on the proportional difference in the rotational inertia of the driving wheel and the driven wheel during a power outage, and thus adjusting the short-circuit braking torque of the two drive motors, the tension stability problem of the power-off braking of the dual-belt system can be completely solved, maintaining stable braking tension under any radius.

[0013] In another possible implementation, the moment of inertia parameter of the driving wheel is greater than that of the driven wheel; the backup microcontroller generates a control signal by performing the following steps: determining a first duty cycle parameter as 1; determining a second duty cycle parameter based on the reciprocal of the ratio of the moment of inertia parameter of the driving wheel to that of the driven wheel; generating a first duty cycle signal based on the first duty cycle parameter, and generating a second duty cycle signal based on the second duty cycle parameter.

[0014] This possible implementation presents a specific scheme for determining the duty cycle parameters of the two motors based on the proportional difference between the rotational inertia parameters of the driving and driven wheels when a power failure occurs and the moment of inertia parameter of the driving wheel is greater than that of the driven wheel. Specifically, the duty cycle parameter of the driving wheel is set to 1, and the PWM value of the short-circuit brake is adjusted by regulating the duty cycle parameter of the driven wheel. Through the cooperation of the two motors, the dual-belt transmission system can be quickly and safely brought to a stop.

[0015] In another possible implementation, the moment of inertia parameter of the driving wheel is less than that of the driven wheel; the backup microcontroller generates a control signal by performing the following steps: determining the second duty cycle parameter as 1; determining the first duty cycle parameter based on the ratio of the moment of inertia parameter of the driving wheel to that of the driven wheel; generating the first duty cycle signal based on the first duty cycle parameter; and generating the second duty cycle signal based on the second duty cycle parameter.

[0016] This possible implementation presents a specific scheme for determining the duty cycle parameters of the two motors based on the proportional difference between the rotational inertia parameters of the driving and driven wheels when a power failure occurs and the moment of inertia parameter of the driving wheel is less than that of the driven wheel. Specifically, the duty cycle parameter of the driven wheel is set to 1, and the PWM value of the short-circuit brake is adjusted by regulating the duty cycle parameter of the driving wheel. Through the cooperation of the two motors, the dual-belt drive system can be quickly and safely brought to a stop.

[0017] In another possible implementation, the backup microcontroller is also used to: update the moment of inertia parameters of the driving wheel and the driven wheel based on the braking time; update the first duty cycle parameter and the second duty cycle parameter based on the updated moment of inertia parameters of the wheel and the driven wheel; generate a first duty cycle signal based on the updated first duty cycle parameter; and generate a second duty cycle signal based on the updated second duty cycle parameter.

[0018] Considering that the proposed solution based on this possibility would have a large computational overhead, resulting in a large energy consumption on the backup power supply components, the solution based on braking time to update parameters can be enabled or disabled. For example, a configuration switch can be set. When configured to be enabled, the parameters will be updated in real time or at a certain period (e.g., 0.1s) during the braking process. When configured to be disabled, the parameters will not be updated during the braking process, and the rotational inertia parameters of the driving wheel and the driven wheel will be regarded as remaining unchanged, keeping the duty cycle control parameters unchanged until the motor stops.

[0019] In another possible implementation, the moment of inertia parameter of the driving wheel is equal to that of the driven wheel; the standby microcontroller generates control signals by performing the following steps: determining the first duty cycle parameter and the second duty cycle parameter to be the same parameter value; generating a first duty cycle signal based on the second duty cycle parameter, and generating a second duty cycle signal based on the second duty cycle parameter.

[0020] When the rotational inertia parameters of the driving wheel and the driven wheel are the same, the first duty cycle parameter and the second duty cycle parameter are the same. That is, the two motors can provide equal braking torque to ensure that the double belt transmission system gradually stops under the action of back electromotive force, and the tension of the load is safe.

[0021] In another possible implementation, the main control component also includes a main microcontroller unit; a backup control unit is communicatively connected to the main microcontroller unit, and the backup control unit obtains the rotational inertia parameters of the driving wheel and the driven wheel through the following steps: reading the rotational inertia parameters of the driving wheel and the driven wheel from the main microcontroller unit; or, reading the radius estimate of the driving wheel and the radius estimate of the driven wheel from the main microcontroller unit; determining the rotational inertia parameter of the driving wheel based on the radius estimate of the driving wheel; and determining the rotational inertia parameter of the driven wheel based on the radius estimate of the driven wheel.

[0022] In another possible implementation, the relationship between the state parameters of the driving wheel and the driven wheel and the control parameters is determined based on the load tension model, which is also used to estimate the load tension fluctuation value and braking time during braking.

[0023] In other words, this application has modeled the tension response during the braking process to obtain a tension model. Through this tension model, the tension fluctuation value and total time of braking can be accurately estimated, and the control effect of load tension during the braking process can be determined in advance.

[0024] In another possible implementation, the tension model is also used to guide the tuning of the parameters of the first drive motor and the second drive motor, as well as the tuning of the parameters of the drive unit.

[0025] In this possible implementation, the parameters of the motor (including the first drive motor and the second drive motor) and the parameters of the drive unit can be optimized based on the tension model and the expected value of braking performance.

[0026] Optionally, the parameters of the first drive motor include its internal resistance parameter, the parameters of the second drive motor include its internal resistance parameter, and the parameters of the drive unit include the resistance parameters of the first drive circuit and the resistance parameters of the second drive circuit. By optimizing the motor and drive parameters, the braking effect is improved.

[0027] In another possible implementation, a dual-reel delivery system is applied to a magnetic tape storage system, with the load being the magnetic tape.

[0028] Secondly, this application also provides a braking method for braking a dual-belt transmission system, the dual-belt transmission system including a driving wheel and a driven wheel, a first drive motor for driving the driving wheel to rotate and a second motor for driving the driven wheel to rotate, the driving wheel and the driven wheel having loads. The braking method provided by this application includes: receiving an abnormal signal, the abnormal signal indicating that an abnormality has occurred in the dual-belt transmission system; generating a control signal based on the state parameters of the driving wheel and the driven wheel at the time of the abnormality, to control the first drive motor to brake with a first braking torque and the second drive motor to brake with a second braking torque, so as to keep the tension of the load within a safe range.

[0029] In one possible implementation, the dual-reel conveyor system further includes a main control component, which includes a first MOS bridge and a second MOS bridge. The first MOS bridge is electrically connected to the first drive motor, and the second MOS bridge is electrically connected to the second drive motor. The abnormal signal is a power-down abnormal signal, indicating that a power-down abnormality has occurred in the dual-reel conveyor system. The control signals include a first duty cycle signal and a second duty cycle signal. The braking method provided in this application further includes: sending the first duty cycle signal to the first drive circuit to generate a first PWM signal, which is used to control the on / off ratio of the first MOS bridge to control the first drive motor to perform short-circuit braking with a first braking torque; and sending the second duty cycle signal to the second drive circuit to generate a second PWM signal, which is used to control the on / off ratio of the second MOS bridge to control the second drive motor to perform short-circuit braking with the second braking torque.

[0030] In another possible implementation, the state parameters of the driving wheel include the rotational inertia parameters of the driving wheel, and the state parameters of the driven wheel include the rotational inertia parameters of the driven wheel. A specific implementation for generating a control signal based on the state parameters of the driving wheel and the driven wheel when a power failure occurs is as follows: the control signal is generated based on the ratio of the rotational inertia parameters of the driving wheel and the driven wheel.

[0031] In another possible implementation, a specific implementation of generating a control signal based on the ratio of the rotational inertia parameter of the driving wheel to that of the driven wheel is as follows: determining that the rotational inertia parameter of the driving wheel is greater than that of the driven wheel; setting a first duty cycle parameter to 1; determining a second duty cycle parameter based on the reciprocal of the ratio of the rotational inertia parameter of the driving wheel to that of the driven wheel; generating a first duty cycle signal based on the first duty cycle parameter; and generating a second duty cycle signal based on the second duty cycle parameter.

[0032] In another possible implementation, a specific method for generating a control signal based on the ratio of the rotational inertia parameters of the driving wheel and the driven wheel is as follows: determining that the rotational inertia parameter of the driving wheel is less than that of the driven wheel; setting the second duty cycle parameter to 1; determining the first duty cycle parameter based on the ratio of the rotational inertia parameters of the driving wheel and the driven wheel; generating a first duty cycle signal based on the first duty cycle parameter; and generating a second duty cycle signal based on the second duty cycle parameter.

[0033] In another possible implementation, the control signal is generated based on the ratio of the rotational inertia parameters of the driving wheel and the driven wheel, and further includes: updating the rotational inertia parameters of the driving wheel and the driven wheel based on the braking time; updating a first duty cycle parameter and a second duty cycle parameter based on the updated rotational inertia parameters of the driving wheel and the driven wheel; generating a first duty cycle signal based on the updated first duty cycle parameter; and generating a second duty cycle signal based on the updated second duty cycle parameter.

[0034] In another possible implementation, a specific implementation of generating a control signal based on the ratio of the rotational inertia parameter of the driving wheel to that of the driven wheel is as follows: determining that the rotational inertia parameter of the driving wheel is equal to that of the driven wheel; determining that the first duty cycle parameter and the second duty cycle parameter are the same parameter value; generating the first duty cycle signal based on the second duty cycle parameter, and generating the second duty cycle signal based on the second duty cycle parameter.

[0035] In another possible implementation, a control signal is generated based on the state parameters of the driving wheel and the driven wheel when the power failure occurs, and prior to this, the rotational inertia parameters of the driving wheel and the driven wheel are obtained.

[0036] In another possible implementation, the main control component also includes a main microcontroller unit; a specific implementation for obtaining the rotational inertia parameters of the driving wheel and the driven wheel is as follows: read the rotational inertia parameters of the driving wheel and the driven wheel from the main microcontroller unit; or, read the radius estimates of the driving wheel and the driven wheel from the main microcontroller unit; determine the rotational inertia parameters of the driving wheel based on the radius estimate of the driving wheel; and determine the rotational inertia parameters of the driven wheel based on the radius estimate of the driven wheel.

[0037] In another possible implementation, the relationship between the state parameters of the driving wheel and the driven wheel and the control parameters is determined based on the load tension model, which is also used to estimate the load tension fluctuation value and braking time during braking.

[0038] In another possible implementation, the tension model is also used to guide the tuning of the parameters of the first drive motor and the second drive motor, as well as the tuning of the parameters of the drive unit.

[0039] In another possible implementation, the parameters of the first drive motor include the internal resistance parameter of the first drive motor, the parameters of the second drive motor include the internal resistance parameter of the second drive motor, and the parameters of the drive unit include the resistance parameter of the first drive circuit and the resistance parameter of the second drive circuit.

[0040] In another possible implementation, a dual-reel delivery system is applied to a magnetic tape storage system, with the load being the magnetic tape.

[0041] Thirdly, embodiments of this application provide a microcontroller unit including a memory and a processor, wherein the memory stores instructions that, when executed by the processor, cause the method described in the second aspect or any possible implementation of the second aspect to be implemented.

[0042] Fourthly, embodiments of this application provide a magnetic tape storage system, including the braking system described in the first aspect or any possible implementation of the first aspect.

[0043] Fifthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, causes the method described in the second aspect or any possible implementation thereof to be implemented.

[0044] In a sixth aspect, embodiments of this application also provide a computer program or computer program product, the computer program or computer program product including instructions that, when executed, cause a computer to perform the method described in the second aspect or any possible implementation of the second aspect.

[0045] In a seventh aspect, embodiments of this application also provide a chip including at least one processor and a communication interface, the processor being configured to perform the methods described in the second aspect or any possible implementation thereof.

[0046] It is understandable that the beneficial effects of aspects two through seven mentioned above can be found in the relevant descriptions in aspect one above, and will not be repeated here for the sake of brevity. Attached Figure Description

[0047] Figure 1 A schematic diagram of a magnetic tape storage system (also known as a magnetic tape drive) is shown.

[0048] Figure 2 and Figure 3 The diagrams show two different parameter configurations for braking by fully depressing the driven wheel brake.

[0049] Figure 4 A control implementation diagram of a magnetic tape storage system provided in this application embodiment;

[0050] Figure 5 A circuit diagram for short-circuit braking is shown;

[0051] Figure 6 This is the FOC control diagram for the tape reel motor under normal operating conditions.

[0052] Figure 7 A schematic diagram illustrating the motion state of the belt winding system during an unexpected power outage braking event.

[0053] Figure 8 The implementation architecture of the safety braking control algorithm provided in the embodiments of this application is shown;

[0054] Figure 9 A schematic diagram comparing the tension curves of the braking scheme of this application and the braking scheme that only brakes the driven wheel is shown when the mass of the driving wheel is greater than the mass of the driven wheel.

[0055] Figure 10 A schematic diagram comparing the tension curves of the braking scheme of this application and the braking scheme that only brakes the driven wheel is shown when the mass of the driving wheel is less than the mass of the driven wheel.

[0056] Figure 11 The diagram shows a comparison of the tension curves between the braking scheme of this application and the braking scheme for uncontrolled free-slipping when the mass of the driving wheel is equal to the mass of the driven wheel. Detailed Implementation

[0057] The term "and / or" used in this article describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. The symbol " / " in this article indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0058] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same properties in the description of embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such processes, methods, systems, products, or apparatus.

[0059] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0060] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0061] The braking system and method provided in this application can be applied to safely brake a dual-reel transmission system in the event of an abnormal power failure. The dual-reel transmission system can be any reel system that requires load tension. For example, the tape drive reel system in a magnetic tape storage system, the paper reel system in the papermaking industry, and the fabric reel system in the textile industry all have requirements for load tension during operation (including normal operation and braking process). If the tension is too low, the load will become loose; if the tension is too high, the load will be damaged.

[0062] The following embodiments of this application use a magnetic tape storage system as an example to introduce the braking system and method provided in this application. Other systems are similar and can be implemented by referring to these embodiments.

[0063] There are various braking schemes in the relevant technical solutions. For example, the first technical solution is a braking scheme for three-phase DC motors, such as permanent-magnet synchronous motors (PMSMs), which includes: 1. Mechanical braking, which stops the motor by braking devices such as brake pads, brake drums, and brake discs; 2. Electronic reverse braking, which changes the internal magnetic field of the motor to make the motor torque negative, thus quickly stopping the motor; 3. Electronic back electromotive force braking, which connects the three-phase currents by short-circuiting and uses the back electromotive force to generate braking torque to control the motor to stop running.

[0064] Key advantages and disadvantages: Each braking technology has its specific application scenarios and advantages and disadvantages. Choosing the appropriate braking method depends on the specific application requirements and motor characteristics. Mechanical braking is simple and easy to implement, but its disadvantages include unstable braking effect and susceptibility to friction damage; reverse braking causes significant changes in the internal magnetic field of the motor, easily damaging it; braking using back electromotive force causes less damage to the motor, but requires additional circuitry and control units. Depending on the specific scenario requirements, these strategies can all stably control the safe braking of a single motor. However, these three solutions are only applicable to a single motor and cannot be directly applied to the control of two motors working together for braking in a tape winding system.

[0065] The second related technical solution, the anti-lock braking system (ABS), is a safety braking control system that prevents wheel lock-up and slippage. Through algorithm design, it controls the relative slippage between the wheels and the ground, ensuring that the coefficient of friction is close to its maximum value (no slippage), and utilizes the maximum friction force to achieve the goals of fastest braking and shortest braking distance. The key innovation of this patent is the use of multiple wheel speed sensors to detect wheel speed in real time. After analysis and processing by the controller, the braking force is dynamically adjusted to prevent the wheels from locking up and slipping during braking.

[0066] Key advantages and disadvantages: This solution can be applied to multi-object coordinated braking in automotive driving or similar scenarios, controlling the system to stop stably and preventing lock-up and slippage, thus greatly improving safety. ABS braking systems require monitoring the rotational speed of each wheel and updating braking force in real time, and the entire system has no fragile components. However, in the event of an unexpected power outage, the tape system cannot monitor the system status in real time. Furthermore, unlike automobiles which have suspension support, the tape system relies solely on a single flexible tape connection, therefore, this system not only requires control of speed and braking distance but also imposes strict requirements on tension.

[0067] The third related technical solution employs a novel structural design using gears, chains, and belts, which improves the power of the tape reel system and enhances its braking capability. When the driving force applied by the active motor is removed from the rotating components of the tape reel and take-up reel, the resistance from the driven mechanism connected to it is sufficient to brake the rotating components without the aid of braking friction. The drive and braking mechanisms work directly in coordination. The core innovation of this solution lies in significantly enhancing the adjustable braking force through an auxiliary transmission system, and possessing the ability to adjust the braking intensity to adapt to different tape quality and speed requirements.

[0068] Main advantages and disadvantages: This scheme improves the power of the tape reel system and enhances its braking capability, but its mechanical structure is complex. The two reels are equipped with an additional set of driven mechanisms for coordination, which increases the number of system state variables that need to be detected. In the event of an unexpected power failure, more situations need to be considered, which increases the computational complexity. This scheme cannot be applied to situations where the tape drive experiences an unexpected power failure.

[0069] In summary, due to their respective limitations, the aforementioned technical solutions cannot meet the requirements for safe braking of the dual-reel tape transfer system in the event of an unexpected power outage.

[0070] To facilitate understanding of the braking system and method provided in the embodiments of this application, some technical terms involved in the embodiments of this application will be briefly explained below.

[0071] Magnetic magnetic tape: a magnetic storage material that records information by recording changes in magnetic fields, usually wound into rolls.

[0072] Tape reel / driven wheel: The reel in the tape drive's reel system is filled with magnetic tape media and has an embedded permanent magnet synchronous motor responsible for feeding the tape outwards.

[0073] Take-up reel / drive wheel: The reel in the tape drive's tape reel system that actively pulls the tape medium. It has an embedded permanent magnet synchronous motor responsible for taking up the tape.

[0074] Data track: All data information is recorded and stored in an orderly manner on magnetic tape media, and each record is a data track.

[0075] Park transformation: Currently, it is the most commonly used coordinate transformation for analyzing the operation of synchronous motors and induction motors.

[0076] dq coordinate system: a commonly used coordinate transformation method in the analysis of motors and power systems.

[0077] The specific implementation of the braking system and method provided in this application is described in detail below with reference to the accompanying drawings and embodiments.

[0078] Figure 1 A schematic diagram of a magnetic tape storage system (also known as a magnetic tape drive) is shown. Figure 1 a) is a schematic diagram of the main structure of the magnetic tape drive. Figure 1 Figure b) is a schematic diagram of the data tape surface of the magnetic tape medium. The electromechanical design of a magnetic tape storage system is mainly divided into two parts: the dual-reel delivery system and the head tracking system, such as... Figure 1 As shown, the dual-reel delivery system dynamically adjusts the speeds of two drive motors (e.g., PMSM or BLDC motors) based on the real-time status of the magnetic tape and reel, ensuring smooth and repeated rewinding of the thin magnetic tape medium between the tape and reel with uniform linear speed and stable micro-tension. Furthermore, the head tracking system, by controlling the displacement of one head (read / write head), can precisely follow many data tracks on the magnetic tape medium, completing the write / read operations in each track. The two systems work closely together to achieve efficient data storage on the magnetic tape medium.

[0079] Based on the characteristics of magnetic tape storage systems, in the event of an unexpected power outage, dual-reel systems face the following main challenges in implementing a safe and reliable braking algorithm and braking process:

[0080] High inertia: Due to the continuous increase in tape length, the weight and rotational inertia of the entire system are much higher than those of traditional tape drives, which poses a new challenge to the system's acceleration and deceleration performance.

[0081] Time-varying parameters: Even more serious is that the moment of inertia of the two belt reels changes in real time during the transmission of power, and the differences are obvious under different states. In uncontrolled scenarios such as unexpected power outages, the belt can be easily stretched and may even face the risk of breakage.

[0082] Limited operation: When the tape drive system experiences an abnormal power failure, only a limited backup power may be retained for final failsafe handling. The only operations that can be performed include extremely low-power operations such as controlling MOS switches.

[0083] High performance requirements: Under the above-mentioned 'barren' conditions, the system needs to coordinate and control the dual-wrap system to provide reliable belt tension to ensure that the system stops safely without damaging the belt.

[0084] In summary, unexpected power failure braking control is a key technology for improving the reliability of tape drive systems, and it is also the technical problem to be solved by the embodiments of this application.

[0085] In other words, the braking scheme provided in this application requires a low-complexity control algorithm, utilizing only limited backup power and limited operations to achieve safe braking of the magnetic tape storage system. The entire braking process must ensure reliable tension, preventing both loosening and breakage. The main technical problems to be solved are:

[0086] Limited control methods: In the event of an unexpected power outage, it is impossible to precisely control physical parameters such as current. The braking system can only adjust the braking force by controlling low-power operations such as MOS switches.

[0087] Wide parameter range: With changes in motor speed and tape reel radius, the system may face entirely different parameter configurations during braking-based startup. In an unbalanced state, improper operation may cause tape breakage, resulting in irreversible damage to the storage medium. Figure 2 and Figure 3 The diagrams illustrate braking by fully depressing the driven wheel brake under two different parameter configurations. Figure 2 As shown, the radius of the driven wheel is larger than that of the driving wheel, meaning the moment of inertia of the driven wheel is greater than that of the driving wheel. In this case, braking by fully depressing the driven wheel can safely bring the vehicle to a stop, but there is a risk of excessive tension. However... Figure 3 In this case, the radius of the driven wheel is smaller than that of the driving wheel, meaning the moment of inertia of the driven wheel is smaller than that of the driving wheel. When braking is performed by braking the driven wheel with the brake pedal pressed down, the magnetic tape becomes loose and reverses, and may even eventually break unexpectedly.

[0088] Low computing cost: In the event of an unexpected power outage, the system can only provide ultra-low power chips and circuits for backup operation, and has limited computing power, making it unable to run complex calculations.

[0089] Tension control: There is no rigid connection between the two reels; they are connected only by a magnetic tape medium with a thickness of only a few micrometers. Therefore, during braking, the tension on the tape must be precisely controlled to ensure that it remains within a small positive range, neither too loose nor too strong to prevent breakage.

[0090] In view of this, embodiments of this application provide a braking system and method. The braking system includes an anomaly detection component, a backup control component, and a backup power supply component. The anomaly detection component is used to detect whether an anomaly occurs in the dual-belt transmission system. The backup control component is communicatively connected to the anomaly detection component and is used to activate a preset braking control algorithm when an anomaly signal is received, and execute the following steps: based on the state parameters of the driving wheel and the driven wheel at the time of the anomaly, a control signal is generated to control the first drive motor to brake with a first braking torque and the second drive motor to brake with a second braking torque, so as to keep the load tension within a safe range.

[0091] Optionally, the anomaly is a power failure anomaly. That is, the anomaly detection component is used to detect whether a power failure anomaly has occurred in the dual-belt conveyor system. When a power failure anomaly is detected in the dual-belt conveyor system, the anomaly detection component sends a power failure anomaly signal to the backup control component. The backup control component activates the safety brake control algorithm and generates a control signal based on the state parameters of the drive wheel and the driven wheel at the time of the power failure anomaly. The control signal controls the first drive motor to brake with a first braking torque and the second drive motor to brake with a second braking torque, so that the load tension is kept within a safe range.

[0092] Figure 4 This is a control implementation diagram of a magnetic tape storage system provided in an embodiment of this application. Figure 4 As shown, the magnetic tape storage system provided in this application embodiment has two control paths. One is the main control path, which consists of the main control chip, MCU1, MOS driver 1, and the MOS bridges corresponding to the two drive motors. Figure 4 The path shown by the arrow is implemented in the diagram. One path is a backup control path consisting of MCU2, MOS driver 2, and the MOS bridges corresponding to the two drive motors in the backup control component. During normal operation, the main control path controls the tape reel system. In the event of a power failure, the backup control path is immediately activated to safely stop the tape reel system, ensuring that the tape tension is maintained within a safe range. For example, the tape tension is maintained within a small positive range, neither too loose nor too strong to prevent breakage.

[0093] For example, a power failure detection component can be used to perform real-time power failure detection on the tape storage system (which can also be a dual-reel tape delivery system). When a power failure anomaly is detected in the tape storage system, an independent backup power supply component is immediately activated (i.e., Figure 4 The energy storage module shown in the figure) and MCU2, the backup power supply component provides power to MCU2 and MOS driver 2, the power failure detection component sends a power failure abnormal signal to MCU2, MCU2 responds to the power failure abnormal signal and immediately activates the safety braking control algorithm, based on the state parameters of the drive wheel and the driven wheel when the power failure occurs, generates control signals, and controls the drive wheel motor to brake with the first braking torque and the driven wheel motor to brake with the second braking torque through the backup control path to ensure that the tension of the magnetic tape is kept within a safe range.

[0094] Optionally, considering that magnetic tape storage systems are relatively sophisticated systems with high requirements for motor performance, both the drive wheel motor and the driven wheel motor are three-phase motors, such as PMSM motors or BLDC motors.

[0095] Backup power supply components include, for example, energy storage batteries, which are electrically connected to MCU2 and MOS driver 2 respectively, and provide power to MCU2 and MOS driver 2 when the tape storage system experiences a power failure.

[0096] It should be noted that, Figure 4 The components within the dashed box are innovative additions in this application's embodiments, including power-down detection, MCU2, MOS driver 2, and energy storage. Figure 4 This is merely a feasible implementation shown in the embodiments of this application to facilitate understanding, and does not constitute a limitation on this application.

[0097] In one example, the state parameters of the driving wheel and the driven wheel can be rotational inertia. The braking safety control algorithm in MCU2 generates control signals based on the rotational inertia of the driving wheel and the driven wheel, and realizes adaptive adjustment of control parameters according to the rotational inertia of the driving wheel and the driven wheel. This enables safe braking regardless of the rotational position of the driving wheel and the driven wheel, ensuring the safety of the magnetic tape tension.

[0098] Considering that MCU2 is an ultra-low power MCU, in order to reduce the computing power overhead of MCU2, MCU2 can obtain the rotational inertia of the drive wheel and the driven wheel directly from MCU1. For example, MCU2 and MCU1 are connected in communication. During the normal operation cycle of the tape storage system (e.g., when the tape storage system does not experience a power failure), MCU2 obtains the rotational inertia of the drive wheel and the driven wheel from MCU1 in real time. After receiving a power failure signal, MCU2 uses the last obtained rotational inertia (a set of rotational inertia, including the rotational inertia of the drive wheel and the driven wheel) as the rotational inertia of the drive wheel and the driven wheel at the time of the abnormal power failure, or uses the rotational inertia obtained from MCU1 when the power failure signal is received as the rotational inertia of the drive wheel and the driven wheel at the time of the abnormal power failure.

[0099] For example, MCU2 periodically reads the rotational inertia of the driving wheel and the driven wheel in MCU1. After receiving a power failure signal, MCU2 uses the last obtained rotational inertia as the rotational inertia of the driving wheel and the driven wheel at the time of the abnormal power failure.

[0100] In another example, MCU2 obtains radius estimates from MCU1. Each set of radius estimates includes the radius estimates of the driving wheel and the driven wheel. MCU2 calculates the moment of inertia based on the radius estimates obtained during an abnormal power outage. The formulas for calculating the radius estimates and the moment of inertia are shown below:

[0101]

[0102] Among them, J motor R represents the initial moment of inertia of the motor, w represents the width of the magnetic tape medium, ρ represents the density of the magnetic tape medium, R1 represents the radius of the driving pulley, R2 represents the radius of the driven pulley, and R0 represents the radius of the empty reel (i.e., the radius of the driving pulley and the driven pulley for winding the magnetic tape).

[0103] Understandably, the radius of the drive pulley is the distance between its center and the outer surface of the magnetic tape medium wound on it. Similarly, the radius of the driven pulley is the distance between its center and the outer surface of the magnetic tape medium wound on it. During the operation of the magnetic tape storage system, the radii of the drive and driven pulleys change with their rotation. For example, during tape rewinding, the drive and driven pulleys rotate in the same direction, increasing the radius of the drive pulley and decreasing the radius of the driven pulley. During tape feeding, the drive and driven pulleys rotate in opposite directions, decreasing the radius of the drive pulley and increasing the radius of the driven pulley. During normal operation, MCU1 continuously estimates the real-time state of the drive and driven pulleys (including radius estimates, rotational speed, and moment of inertia) and dynamically adjusts the speeds of both motors to ensure that the thin magnetic tape medium undergoes smooth, repeated rewinding operations between the tape reel and the take-up reel with uniform linear speed and stable micro-tension. Therefore, MCU2 obtains the state parameters of the driving wheel and the driven wheel by reading them directly from MCU1.

[0104] The braking system provided in this application embodiment uses an anomaly detection component to detect in real time whether the tape storage system has experienced a power failure. When a power failure is detected, an independent backup power supply component and a backup MCU1 are immediately activated, and a safety braking control algorithm is activated. The corresponding drive circuit adjusts the braking torque of the corresponding motor according to the control output, and finally the two motors of the dual tape transmission system are synchronously and safely stopped.

[0105] For example, MCU1 periodically updates the rotational inertia of the tape winding system (including the rotational inertia of the drive pulley and the driven pulley); when a power failure signal is detected, the backup power supply component is switched, and MCU1 takes over the motor control chip; the safety braking control algorithm on MCU1 is activated, and the braking control duty cycle of the corresponding motor is calculated based on the rotational inertia of the tape winding system when the power failure occurs, and sent to the corresponding drive circuit (the first duty cycle signal is sent to drive circuit 3, and the second duty cycle signal is sent to drive circuit 4, which can also be called an inverter circuit at this time), so that the safe braking of the tape winding system is achieved through the cooperation of the two motors.

[0106] The reasoning process and specific implementation of the safety braking control algorithm in this application are described below.

[0107] In this embodiment, the tension response characteristics of the magnetic tape during braking need to be considered. A safe braking scheme is constructed based on these tension response characteristics to ensure that the tension is maintained within a safe range. To this end, this embodiment accurately characterizes the tension response characteristics of the tape reel system under unexpected power failure by modeling a motor short-circuit braking model and an unexpected power failure braking model of the tape reel system. Therefore, the unexpected power failure braking model can also be called a tension model.

[0108] When the tape drive system (i.e., the dual-reel delivery system) experiences an abnormal power failure, it cannot actively adjust the current magnitude and direction of the motors according to the original normal procedure to stop both motors according to the prescribed deceleration and tension curves. Only a separate, limited safety backup power supply can be used for final fault handling, and the only operable operations are extremely low-power operations such as MOS switch control. Considering the braking technology of three-phase DC motors (such as PMSM or BLDC motors), in the scenario presented in this paper, the appropriate braking method is short-circuit braking.

[0109] Short-circuit braking refers to braking in a manner where the upper (or lower) bridge arm of the motor's drive MOSFET is fully turned on while the lower (or upper) bridge arm is turned off, effectively short-circuiting all three phases of the motor's stator windings. This utilizes the motor's back electromotive force during power loss to dissipate rotational energy through internal resistance heat.

[0110] Figure 5 A circuit diagram for short-circuit braking is shown. (For example...) Figure 5 As shown, connecting T2, T4, and T6 and disconnecting T1, T3, and T5 enables the lower bridge arm to conduct, generating a large short-circuit current. This allows the motor to instantly generate a large braking torque, achieving rapid braking.

[0111] Figure 6 This is the FOC control diagram for the tape motor under normal operating conditions.

[0112] First, for the three-phase tape winding motor in the tape winding system, it is necessary to derive the mathematical expression for the braking resistance during short-circuit braking. Under normal operating conditions, the drive currents of the two three-phase motors are updated in real time using the tape winding control algorithm, and the motor drive control employs the classic vector control strategy (FOC). The winding equations can be transformed to the dq coordinate system using the Park transformation, where the voltages (u) on the d-axis and q-axis are... d u q The expression is as follows:

[0113]

[0114] k e =NΨ m #(3)

[0115] Among them, R s Indicates the internal resistance of the motor, i d L represents the d-axis current of the motor. d This represents the d-axis inductance of the motor, N represents the number of pole pairs, ω represents the motor speed, and i q L represents the q-axis current of the motor. q Ψ represents the q-axis inductance of the motor. m This represents permanent magnet flux linkage, measured in Wb, kJ. eThis indicates the torque coefficient of the motor.

[0116] When switching from normal state to power-off state, short-circuit the motor input u. d u q All become 0, and there is u d =u q =0, we can get the following formula:

[0117]

[0118] According to the torque equation of a three-phase motor, we can obtain:

[0119]

[0120] At this point, K is obtained. f That is, the saturated braking damping of a single motor. Formula (5) is the motor short-circuit braking model constructed in the embodiments of this application.

[0121] The dual-reel system is driven by two permanent magnet synchronous motors, and the load is a magnetic tape under tension. Upon power failure, the system enters a safety mode and initiates a short-circuit brake. To design a reliable safety braking algorithm, a motion model of the dual-reel system during the short-circuit operation needs to be established. According to Newton's second law, the motion model can be described by the following equation, where subscript 1 represents the motor of the driving pulley and subscript 2 represents the motor of the driven pulley.

[0122] Figure 7 A schematic diagram illustrating the motion state of the belt reel system during an unexpected power outage braking event. (See diagram for example.) Figure 7 As shown, when the belt winding system is unexpectedly de-energized, the belt winding system has a velocity to the left due to inertia, and is simultaneously subjected to a Coulomb friction force to the right. At this time, the radii of the driving pulley and the driven pulley are R1 and R2, respectively.

[0123] Since the motor will stop completely in a very short time (on the order of seconds), the time-varying nature of the two radii (R1, R2) and the two moments of inertia (J1, J2) can be ignored, and they can be treated as constants:

[0124]

[0125] Based on the motor short-circuit braking model, the braking torque has the following expression:

[0126]

[0127] The expression for the tension of the magnetic tape is as follows:

[0128]

[0129] Among them, K tape D represents the system's elasticity coefficient [N / m];tape T represents the system damping coefficient [N s / m]; tape The magnetic tape tension value is represented by μ; the Coulomb coefficient of friction is represented by μ; β1 and β2 represent the viscous friction coefficients of the two motors (drive and driven motors) [N·ms], respectively; R1 and R2 represent the real-time radii of the two reels (drive and driven pulleys) [m], respectively; x1 and x2 represent the displacements of the two reels [m], respectively; J1 and J2 represent the real-time moments of inertia of the two wheels (drive and driven pulleys) [kg·m]. 2 ];τ b1 ,τ b2 These represent the braking torque [N m] of the two motors, respectively; K f1 ,K f2 α1 and α2 represent the saturated braking torque coefficients of the two motors [N ms], respectively; α1 and α2 represent the short-circuit PWM duty cycles of the two motors, respectively.

[0130] Taking the derivative of formula (10) twice, D tape Much smaller than K tape , can be ignored, and we get the following expression:

[0131]

[0132] Substituting equations (6)(7)(8)(9) into equation (11), μ and β1, β2 are relatively small and can be ignored, resulting in the following expression for the dynamic response of tension:

[0133]

[0134] Observing the characteristics of the tension expression in formula (12), α1 and α2 correspond to the braking torque control quantities of the short-circuited motor, respectively. A proposal is made to adjust the PWM value of the short-circuited brake based on the relative difference in rotational inertia of the two discs when the power is off. Then there is

[0135]

[0136] The parameters of the two motors are considered to be identical, K f1 =K f2 Then there is

[0137]

[0138] A second-order differential equation relating only to tension was obtained, and α2 is a controllable variable that can be autonomously adjusted. By designing the value of α2, the tension behavior during power-off braking can be altered, ensuring the safety and reliability of the magnetic tape. Once power is restored, the tape reel system can be directly powered on and operate normally, maintaining the competitiveness of magnetic tape storage products.

[0139] The safety braking algorithm of this application embodiment is obtained according to Formula 14, which is the unexpected power failure braking model, also known as the tension model.

[0140] The braking scheme provided in this application is primarily used in the safety control algorithms and implementation strategies of dual-reel tape systems or similar storage systems containing dual reels. Specifically, when any link in the main path encounters a power outage or other malfunction, such as an unexpected power interruption, a main chip output failure, or a single-sided drive power supply abnormality on the drive / driven wheel, refer to... Figure 4 The implementation process for controlling a dual-reel tape system. Specifically, the strategy in this embodiment is: the tape drive activates a backup path and initiates a pre-designed abnormal power-off braking algorithm to achieve a safe and reliable stop of the dual-reel tape system.

[0141] When a power-loss-related fault is detected in the tape reel system, a separate backup MCU is activated. It inputs known parameters from the power-loss state (e.g., the moment of inertia of the drive and driven wheels) to output control signals for the tape reel and take-up reel, which are then sent to the two inverters (i.e.,...). Figure 4 The drive circuits 3 and 4 generate corresponding PWM signals to adjust the torque of the short-circuit brake of the two motors respectively, so as to reliably and safely perform the braking task and protect the information stored in the belt from damage.

[0142] Figure 8 This illustrates the implementation architecture of the safety braking control algorithm provided in an embodiment of this application. Independent of the normal dual-motor tape winding control system, a preparatory state subsystem is designed, which includes a power supply system (…). Figure 8 (Not yet shown) and a low-power MCU. During the normal operation cycle of the tape reel system, this low-power MCU can obtain the radius estimate of the tape reel system in real time, thus obtaining the real-time rotational inertia of the two motors. This information serves as the input signal for the braking algorithm. Once an unexpected power failure signal is received, the safety braking process is initiated. After analysis by the control algorithm, braking control signals for the two motors are output separately.

[0143] The safety braking control algorithm provided in this application involves a tape drive actuator (tape motor) and a driver (motor inverter). Based on the control signal generated by the braking control algorithm, the MCU in the braking system controls the switching of the MOSFETs in the motor inverter, thereby dynamically adjusting the braking torque of the two tape motors according to the state during power failure.

[0144] The braking system provided in this application embodiment can quickly activate the backup control path in case of sudden loss of control of the tape reel system or failure of a single component. Combined with the designed safety braking control algorithm, it can achieve safe deceleration and braking to protect the information of the magnetic tape medium.

[0145] This application embodiment constructs a tension model that can characterize tension performance by modeling the tension response under sudden power outage conditions, in order to explain physical phenomena and propose a safe control strategy to dynamically adjust the braking torque of the two belt reel motors.

[0146] Furthermore, the embodiments of this application can also accurately estimate the tension fluctuations and total braking time during the braking process through a tension model, which can determine the tension control effect in advance.

[0147] In this embodiment of the application, in the event of an unexpected power outage, since a short-circuit braking method is adopted, a resistor is set in the drive circuit (including drive circuit 3 and drive circuit 4) to avoid damage to the equipment due to excessive current.

[0148] Based on the actual load and belt characteristics, the embodiments of this application can also guide the optimization of related parameters such as motor and drive circuit. For example, based on the tension model and the expected braking performance, it can guide the optimization of the internal resistance parameters of the motor and the resistance parameters of the drive circuit (including drive circuit 3 and drive circuit 4) to achieve better braking performance.

[0149] In this embodiment, in the event of an unexpected power outage in the tape winding system, both motors will enter the backup system. Based on the real-time state of the motors at the moment of power failure and the condition that both motors are short-circuited with torque, a dynamic response model of the system is constructed. Furthermore, a method is proposed to adjust the PWM value of the short-circuit brake based on the relative difference in rotational inertia of the two reels at the time of power failure, and a design is implemented. A second-order differential equation relating only to tension was obtained, and α2 is a control variable that can be autonomously adjusted, as shown in Equation 14.

[0150]

[0151] As shown in the above formula, by designing the value of α2, the tension performance during power-off braking can be altered, ensuring the safety and reliability of the magnetic tape. Once power is restored, the tape reel system can be directly powered on and operate normally, maintaining the competitiveness of the magnetic tape storage product. Based on this model, we can convert the short-circuit torque required to quickly and safely stop the two motors under safe tension conditions into a short-circuit PWM value and send it to the inverter circuit.

[0152] The following examples illustrate the application of the braking solution provided in this application in specific instances.

[0153] For example, let's first introduce how the backup system starts and responds to the control of braking torque when the moment of inertia of the driving wheel is greater than that of the driven wheel (J1>J2) and the belt winding system experiences an abnormal power failure.

[0154] When the tape reel system is running normally, it stores real-time radius information in the backup system at a control frequency of 500 microseconds.

[0155] When an error signal of sudden abnormal power failure is detected, the independent backup power supply and the MCU system are activated immediately.

[0156] The backup power supply is responsible for the overall power supply of the independent emergency system, and the MCU reads the radius information in the storage unit and calculates the moment of inertia of the two motors at the power-off moment.

[0157] The braking algorithm module of the MCU system gives α1=1 (the maximum value can be 1, which means that the short-circuited PWM value is 100%), The braking control signal of the driven wheel is given according to the relative difference of the moment of inertia of the two reels during power failure and α1.

[0158] The corresponding inverter circuit receives the control signal and generates a corresponding PWM wave to control the on-off ratio of the MOS tube in the motor short-circuit circuit.

[0159] The braking process is relatively short. If the moment of inertia parameter is regarded as unchanged, the above PWM duty cycle is maintained until the motor stops; or a change curve of the moment of inertia can be designed, and the corresponding system parameters and duty cycle are updated according to the running time of the motor until the motor stops.

[0160] The simulation effect of the braking solution provided by the embodiment of the present application is given below. In the original trial solution, the driven wheel is directly kept in the short-circuit mode, while the driving wheel coasts freely. Since the mass of the driving wheel is larger than that of the driven wheel, the driving wheel has a large moment of inertia and the driven wheel has a small moment of inertia when power fails, which causes the magnetic tape to loosen and unwind.

[0161] Figure 9 It is a schematic diagram comparing the tension curves between the braking solution of the present application and the braking solution that only brakes the driven wheel when the mass of the driving wheel is larger than that of the driven wheel. As Figure 9 shown, with the safety braking solution provided by the embodiment of the present application, the tension change is relatively stable without large fluctuations, can be maintained at a small positive value, and the tape winding system completely stops within 1 second.

[0162] The following describes how the backup system starts and responds to the control of braking torque when the moment of inertia of the driving wheel is smaller than that of the driven wheel (J1<J2) and the tape winding system has an abnormal power failure.

[0163] When the tape winding system is in normal operation, real-time radius information is stored in the backup system at a control frequency of 500 microseconds;

[0164] When an error signal of sudden abnormal power failure is detected, the independent backup power supply and the MCU system are activated immediately;

[0165] The backup power supply is responsible for the overall power supply of the independent emergency system. The MCU reads the radius information in the storage unit and calculates the moment of inertia of the two motors at the moment of power failure.

[0166] The braking algorithm module of the MCU system provides α2 = 1 (the maximum value can be 1, indicating that the short-circuited PWM value is 100%). The braking control signal for the drive wheel is given based on the relative difference in rotational inertia of the two discs when the power is off and α2.

[0167] The corresponding inverter circuit receives the control signal and generates a corresponding PWM wave to control the on / off ratio of the MOSFET in the motor short-circuit circuit.

[0168] The braking process is relatively short. If the moment of inertia parameter is considered constant, the above PWM duty cycle can be maintained until the motor stops. Alternatively, a curve showing the change in rotational inertia can be designed to update the corresponding system parameters and duty cycle according to the motor's running time until the motor stops.

[0169] Figure 10 A schematic diagram comparing the tension curves of the braking scheme of this application and a braking scheme that only brakes the driven wheel is shown when the mass of the driving wheel is less than that of the driven wheel. Figure 10 As shown, under such circumstances, the safety braking scheme provided in this application embodiment ensures that the tension change remains relatively stable without significant fluctuations, maintaining a small positive value, and the winding system comes to a complete stop within 1 second.

[0170] Next, we will introduce the case where the mass of the driving wheel is equal to the mass of the driven wheel.

[0171] When the mass of the driving pulley equals the mass of the driven pulley, and the belt winding system unexpectedly loses power and goes out of control, since the masses on both sides are equal, and the system parameters on both sides are theoretically completely identical at the time of power failure, the following mathematical model exists:

[0172]

[0173] Therefore, by applying equal braking torque (α1=α2) to both motors simultaneously, the system can be ensured to gradually stop under the action of back electromotive force, and the tension performance is safe.

[0174] Figure 11 A schematic diagram comparing the tension curves of the braking scheme of this application and the braking scheme for uncontrolled free-slipping is shown, where the mass of the driving wheel equals the mass of the driven wheel. Figure 11 As shown, the safety braking scheme provided in this application embodiment has relatively stable tension changes without significant fluctuations, and can be maintained at a small positive value.

[0175] Through experimental verification on a real platform, the braking scheme provided in this application embodiment conforms to the model prediction in the prototype experiment. Stable tension braking can be achieved when the belt winding system rotates to any position and speed.

[0176] In another example, as discussed above in this application embodiment, a scenario is where both the driving and driven wheel motors are de-energized. This involves simultaneously starting both motors and applying a short-circuit brake, adjusting only the PWM value of the short-circuit brake to ensure coordinated deceleration and tension maintenance between the two motors. Further consideration allows for the specific classification of these abnormal situations.

[0177] For example, when both motors of the tape winding system are completely de-energized, the implementation method of safety braking control can incorporate the damping of motor rotation and the friction on the path into the tension model of short-circuit braking, derive a more detailed tension response expression, and then use this expression to perform more precise braking control on the tape winding system.

[0178] For example, consider the implementation method of safety braking control when the drive wheel motor of the tape reel loses power. At this time, the driven wheel motor is functioning normally and can provide active reverse current braking, increasing the operating range. Specifically, the braking control of the drive wheel is implemented through a backup control path, while the braking control of the driven wheel is implemented through a main control path. The backup control path brakes the drive wheel motor through short-circuit braking, while the main control path brakes the driven wheel motor through reverse current. For instance, considering the limited backup power supply of the backup control path and the low computing power of the backup MCU (a low-power MCU), the computational burden of the backup MCU is minimized. For example, when a power failure is detected in the drive wheel motor while the driven wheel motor is powered normally, the backup control path generates a control signal with a fixed duty cycle (e.g., a duty cycle of 1) to control the drive wheel motor to perform short-circuit braking. The main control path adjusts the magnitude of the reverse current based on the state parameters of the drive and driven wheels, thereby adjusting the braking torque of the driven wheel to ensure that the tape tension remains within a safe range.

[0179] For example, consider the implementation method of safety braking control when the driven wheel motor of the tape reel loses power. At this time, the driving wheel motor is functioning normally and can provide active reverse current braking, increasing the operating range. Specifically, the braking control of the driven wheel is achieved through a backup control path, while the braking control of the driving wheel is achieved through a main control path. The backup control path brakes the driven wheel motor through short-circuit braking, while the main control path brakes the driving wheel motor through reverse current. For instance, considering the limited backup power supply of the backup control path and the low computing power of the backup MCU (a low-power MCU), the computational burden of the backup MCU is minimized. For example, when a power failure is detected in the driven wheel motor while the driving wheel motor is powered normally, the backup control path generates a control signal with a fixed duty cycle (e.g., a duty cycle of 1) to short-circuit the driven wheel motor. The main control path adjusts the magnitude of the reverse current based on the state parameters of the driving and driven wheels, thereby adjusting the braking torque of the driving wheel to ensure that the tape tension remains within a safe range.

[0180] Embodiments of this application also provide a magnetic tape storage system, including the braking system mentioned above, which can safely stop the tape reel system by means of the braking method mentioned above when an abnormality occurs, ensuring that the magnetic tape tension is maintained within a safe range.

[0181] Embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, wherein when the computer instructions are executed by a processor, the aforementioned method is implemented.

[0182] An embodiment of this application provides a chip including at least one processor and an interface, wherein the at least one processor determines program instructions or data through the interface; the at least one processor is used to execute the program instructions to implement the method mentioned above.

[0183] Embodiments of this application provide a computer program or computer program product that includes instructions that, when executed, cause a computer to perform the methods mentioned above.

[0184] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0185] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented using hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0186] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A braking system, characterized in that, This braking system is used for braking a dual-belt drive system, which includes a drive pulley and a driven pulley, a first drive motor for driving the drive pulley to rotate, and a second motor for driving the driven pulley to rotate. The drive pulley and the driven pulley have loads. The braking system includes: An anomaly detection component is used to detect whether an anomaly occurs in the dual-reel tape transfer system; A backup control component, communicatively connected to the anomaly detection component, is used to activate a preset braking control algorithm and execute the following steps upon receiving an anomaly signal: Based on the state parameters of the driving wheel and the driven wheel when the abnormality occurs, a control signal is generated to control the first drive motor to brake with a first braking torque and the second drive motor to brake with a second braking torque, so as to keep the tension of the load within a safe range.

2. The braking system according to claim 1, characterized in that, The dual-reel conveyor system further includes a main control component, which includes a first MOS bridge and a second MOS bridge. The first MOS bridge is electrically connected to the first drive motor, and the second MOS bridge is electrically connected to the second drive motor. The anomalies include power outage anomalies; The backup control component includes: A backup microcontroller unit, which is communicatively connected to the anomaly detection component, is used to generate the control signal based on the state parameters of the driving wheel and the driven wheel when a power failure anomaly signal is received. A backup drive unit is communicatively connected to the backup control unit and electrically connected to the first MOS bridge and the second MOS bridge, respectively. It is used to generate a first PWM signal and a second PWM signal based on the control signal. The first PWM signal is used to control the on / off ratio of the first MOS bridge to control the first drive motor to perform short-circuit braking with the first braking torque. The second PWM signal is used to control the on / off ratio of the second MOS bridge to control the second drive motor to perform short-circuit braking with the second braking torque. The backup power supply component is electrically connected to the backup microcontroller unit and the backup drive unit respectively, and is used to supply power to the backup microcontroller unit and the backup drive unit when a power failure occurs.

3. The braking system according to claim 2, characterized in that, The control signal includes a first duty cycle signal and a second duty cycle signal; The backup drive unit includes a first drive circuit and a second drive circuit. The first drive circuit is used to generate the first PWM signal based on the first duty cycle signal, and the second drive circuit is used to generate the second PWM signal based on the second duty cycle signal.

4. The braking system according to claim 3, characterized in that, The state parameters of the driving wheel include the moment of inertia parameter of the driving wheel, and the state parameters of the driven wheel include the moment of inertia parameter of the driven wheel; The backup microcontroller unit is used to generate the control signal based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel.

5. The braking system according to claim 4, characterized in that, The moment of inertia parameter of the driving wheel is greater than that of the driven wheel; The backup microcontroller unit generates the control signal by performing the following steps: Set the first duty cycle parameter to 1; The second duty cycle parameter is determined based on the reciprocal of the ratio of the moment of inertia parameter of the driving wheel to the moment of inertia parameter of the driven wheel. The first duty cycle signal is generated based on the first duty cycle parameter, and the second duty cycle signal is generated based on the second duty cycle parameter.

6. The braking system according to claim 4, characterized in that, The moment of inertia parameter of the driving wheel is smaller than that of the driven wheel; The backup microcontroller unit generates the control signal by performing the following steps: Set the second duty cycle parameter to 1; The first duty cycle parameter is determined based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel. The first duty cycle signal is generated based on the first duty cycle parameter, and the second duty cycle signal is generated based on the second duty cycle parameter.

7. The braking system according to claim 5 or 6, characterized in that, The backup microcontroller unit is also used for: Based on the braking time, update the rotational inertia parameters of the driving wheel and the driven wheel; Based on the updated moment of inertia parameters of the wheel and the driven wheel, the first duty cycle parameter and the second duty cycle parameter are updated. The first duty cycle signal is generated based on the updated first duty cycle parameter, and the second duty cycle signal is generated based on the updated second duty cycle parameter.

8. The braking system according to claim 4, characterized in that, The moment of inertia parameter of the driving wheel is equal to that of the driven wheel; The backup microcontroller unit generates the control signal by performing the following steps: The first duty cycle parameter and the second duty cycle parameter are set to the same value; The first duty cycle signal is generated based on the second duty cycle parameter, and the second duty cycle signal is generated based on the second duty cycle parameter.

9. The braking system according to any one of claims 4-8, characterized in that, The main control component also includes a main microcontroller unit; The backup control unit is communicatively connected to the main microcontroller unit. The backup control unit obtains the rotational inertia parameters of the driving wheel and the driven wheel through the following steps: Read the rotational inertia parameters of the driving wheel and the driven wheel from the main microcontroller unit; Alternatively, the radius estimates of the driving wheel and the driven wheel can be read from the main microcontroller unit; The rotational inertia parameter of the driving wheel is determined based on the radius estimate of the driving wheel; The rotational inertia parameter of the driven wheel is determined based on the radius estimate of the driven wheel.

10. The braking system according to any one of claims 3-9, wherein the relationship between the state parameters of the driving wheel and the state parameters of the driven wheel and the control parameters is determined based on a tension model of the load, and the tension model is further used to estimate the tension fluctuation value of the load and the braking time during the braking process.

11. The braking system according to claim 10, characterized in that, The tension model is also used to guide the optimization of the parameters of the first drive motor and the second drive motor, as well as the optimization of the parameters of the drive unit.

12. The braking system according to claim 11, characterized in that, The parameters of the first drive motor include the internal resistance parameter of the first drive motor, the parameters of the second drive motor include the internal resistance parameter of the second drive motor, and the parameters of the drive unit include the resistance parameter of the first drive circuit and the resistance parameter of the second drive circuit.

13. The braking system according to any one of claims 1-12, characterized in that, The dual-reel delivery system is used in a magnetic tape storage system, and the load is a magnetic tape.

14. A braking method, characterized in that, A method for braking a dual-belt drive system, the dual-belt drive system including a drive pulley and a driven pulley, a first drive motor for driving the drive pulley to rotate and a second motor for driving the driven pulley to rotate, wherein the drive pulley and the driven pulley have loads, the method comprising: An abnormal signal is received, indicating that the dual-reel conveyor system has malfunctioned; Based on the state parameters of the driving wheel and the driven wheel when the abnormality occurs, a control signal is generated to control the first drive motor to brake with a first braking torque and the second drive motor to brake with a second braking torque, so as to keep the tension of the load within a safe range.

15. The method according to claim 14, characterized in that, The dual-reel conveyor system further includes a main control component, which includes a first MOS bridge and a second MOS bridge. The first MOS bridge is electrically connected to the first drive motor, and the second MOS bridge is electrically connected to the second drive motor. The abnormal signal is a power failure signal, which indicates that the dual-reel conveyor system has experienced a power failure. The control signal includes a first duty cycle signal and a second duty cycle signal; the method further includes: The first duty cycle signal is sent to the first drive circuit to generate a first PWM signal. The first PWM signal is used to control the on / off ratio of the first MOS bridge to control the first drive motor to perform short-circuit braking with the first braking torque. The second duty cycle signal is sent to the second drive circuit to generate a second PWM signal. The second PWM signal is used to control the on / off ratio of the second MOS bridge to control the second drive motor to perform short-circuit braking with the second braking torque.

16. The method according to claim 15, characterized in that, The state parameters of the driving wheel include the moment of inertia parameter of the driving wheel, and the state parameters of the driven wheel include the moment of inertia parameter of the driven wheel; The generation of control signals based on the state parameters of the driving wheel and the driven wheel at the time of the power failure includes: The control signal is generated based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel.

17. The method according to claim 16, characterized in that, The generation of the control signal based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel includes: The moment of inertia parameter of the driving wheel is determined to be greater than that of the driven wheel; Set the first duty cycle parameter to 1; The second duty cycle parameter is determined based on the reciprocal of the ratio of the moment of inertia parameter of the driving wheel to the moment of inertia parameter of the driven wheel. The first duty cycle signal is generated based on the first duty cycle parameter, and the second duty cycle signal is generated based on the second duty cycle parameter.

18. The method according to claim 16, characterized in that, The generation of the control signal based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel includes: The moment of inertia parameter of the driving wheel is determined to be less than that of the driven wheel; Set the second duty cycle parameter to 1; The first duty cycle parameter is determined based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel. The first duty cycle signal is generated based on the first duty cycle parameter, and the second duty cycle signal is generated based on the second duty cycle parameter.

19. The method according to claim 17 or 18, characterized in that, The method of generating the control signal based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel further includes: Based on the braking time, update the rotational inertia parameters of the driving wheel and the driven wheel; Based on the updated moment of inertia parameters of the wheel and the driven wheel, the first duty cycle parameter and the second duty cycle parameter are updated. The first duty cycle signal is generated based on the updated first duty cycle parameter, and the second duty cycle signal is generated based on the updated second duty cycle parameter.

20. The method according to claim 16, characterized in that, The generation of the control signal based on the ratio of the rotational inertia parameter of the driving wheel to the rotational inertia parameter of the driven wheel includes: The moment of inertia parameter of the driving wheel is determined to be equal to the moment of inertia parameter of the driven wheel; The first duty cycle parameter and the second duty cycle parameter are set to the same value; The first duty cycle signal is generated based on the second duty cycle parameter, and the second duty cycle signal is generated based on the second duty cycle parameter.

21. The method according to any one of claims 16-20, characterized in that, The process of generating a control signal based on the state parameters of the driving wheel and the driven wheel at the time of the power failure includes, prior to: Obtain the rotational inertia parameters of the driving wheel and the driven wheel.

22. The method according to claim 21, characterized in that, The main control component also includes a main microcontroller unit; The step of obtaining the rotational inertia parameters of the driving wheel and the driven wheel includes: Read the rotational inertia parameters of the driving wheel and the driven wheel from the main microcontroller unit; Alternatively, the radius estimates of the driving wheel and the driven wheel can be read from the main microcontroller unit; The rotational inertia parameter of the driving wheel is determined based on the radius estimate of the driving wheel; The rotational inertia parameter of the driven wheel is determined based on the radius estimate of the driven wheel.

23. The method according to any one of claims 15-22, characterized in that, The relationship between the state parameters of the driving wheel and the state parameters of the driven wheel and the control parameters is determined based on the tension model of the load. The tension model is also used to estimate the tension fluctuation value of the load and the braking time during the braking process.

24. The method according to claim 23, characterized in that, The tension model is also used to guide the optimization of the parameters of the first drive motor and the second drive motor, as well as the optimization of the parameters of the drive unit.

25. The method according to claim 24, characterized in that, The parameters of the first drive motor include the internal resistance parameter of the first drive motor, the parameters of the second drive motor include the internal resistance parameter of the second drive motor, and the parameters of the drive unit include the resistance parameter of the first drive circuit and the resistance parameter of the second drive circuit.

26. The method according to any one of claims 14-25, characterized in that, The dual-reel delivery system is used in a magnetic tape storage system, and the load is a magnetic tape.

27. A microcontroller unit, comprising a memory and a processor, characterized in that, The memory stores instructions that, when executed by a processor, cause the method described in any one of claims 14-26 to be implemented.

28. A magnetic tape storage system, characterized in that, Including the braking system as described in any one of claims 1-13.

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