Universal serial bus (USB) flash disk hot plug protection self-adaptive current regulation and control system

Abstract

The invention relates to the technical field of USB flash disks, in particular to a USB flash disk hot plug protection self-adaptive current regulation and control system. The detection module is used for detecting current and voltage of the USB flash disk in a running process in real time; the storage unit is used for storing historical use data of the USB flash disk; the analysis unit is used for comparing the slope with a slope threshold value when the USB flash disk is just accessed, and correcting the maximum current according to the wear coefficient in response to the situation that the slope is smaller than the slope threshold value; calculating the overall resistance change rate, comparing the overall resistance change rate with a change rate threshold value, and determining the maximum value of the reverse current according to the overall resistance change rate, the maximum current capable of being borne by the USB flash disk and the electric charge quantity of the USB flash disk capacitor in response to the situation that the overall resistance change rate is greater than the change rate threshold value. The wear coefficient is calculated according to the historical connection times, the contact resistance and the slope, and the allowable maximum working current is dynamically adjusted, so that oxidation of the USB flash disk interface is delayed, and the service life of the USB flash disk is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of U disks, and in particular to a U disk hot-plug protection adaptive current control system. Background Art

[0002] The hot-swap capability of Universal Serial Bus (USB) storage devices (such as USB flash drives) is a key feature of modern computer systems, allowing users to freely plug and unplug devices without turning off the host power or restarting the system.

[0003] In the prior art, the implementation of hot plugging relies on the electrical isolation design at the hardware level and the dynamic identification mechanism driven by the operating system. However, as the USB flash drive is used more and more times, the connector will wear out, causing the resistance to increase. This will cause the connector to generate heat and accelerate oxidation, thereby affecting the dynamic identification mechanism driven by the operating system, resulting in a short service life of the USB flash drive. Summary of the invention

[0004] The purpose of the present invention is to provide a USB flash drive hot-swap protection adaptive current control system to solve the problem in the prior art that during the use of the USB flash drive, as the number of uses increases, the joint position will wear out, resulting in increased resistance, which will cause the joint position to generate heat and accelerate oxidation, thereby affecting the dynamic recognition mechanism driven by the operating system, thereby resulting in a short service life of the USB flash drive.

[0005] The present invention provides a U disk hot plug protection adaptive current control system, comprising: U disk, equipped with hot-swap protection unit; A detection module, which is connected to the USB flash drive and is used to detect the current and voltage of the USB flash drive in real time during operation; An analysis module, which is connected to the detection module and the USB flash drive, is configured with an analysis unit and a storage unit, wherein: The storage unit is used to store historical usage data of the USB flash drive, including: USB flash drive information and its corresponding historical connection times, contact resistance, and threshold standards for determination; The analysis unit is used to compare the slope of the current curve with the slope threshold when the USB flash drive is just connected, and in response to the slope being less than the slope threshold, correct the maximum current according to the wear coefficient; wherein the wear coefficient is determined according to the number of historical connections, the slope and the contact resistance; During data transmission, the overall resistance change rate is calculated and compared with the change rate threshold. In response to the overall resistance change rate being greater than the change rate threshold, the maximum value of the reverse current is determined based on the overall resistance change rate, the maximum current that the U disk can withstand, and the charge of the U disk capacitor.

[0006] As a preferred technical solution of the USB flash drive hot-swap protection adaptive current control system, the wear coefficient is positively correlated with the historical connection times and the contact resistance, and negatively correlated with the slope.

[0007] As a preferred technical solution of the adaptive current control system for USB hot-swap protection, the slope of the current curve is compared with the slope threshold to determine whether the contact resistance meets the standard. In response to the slope being less than the slope threshold, the maximum current is corrected according to the wear coefficient, and the value of the corrected maximum current is negatively correlated with the wear coefficient. Or, in response to the slope being greater than or equal to the slope threshold, it is determined that the contact resistance meets a standard.

[0008] As an optimal technical solution for the USB hot-swap protection adaptive current control system, in response to the correction of the maximum current according to the wear coefficient, data transmission is suspended and waits for all cached data to be stored in the USB storage medium, then the maximum current is corrected and data transmission is restarted.

[0009] As a preferred technical solution for the USB flash drive hot-swap protection adaptive current control system, the overall resistance change rate is calculated and compared with the change rate threshold, and the reason for the overall resistance increase is determined according to the comparison result, including: In response to the overall resistance change rate being greater than a change rate threshold, determining that the reason for the overall resistance increase is that the contact resistance increases due to the USB flash drive being pulled out; In response to the overall resistance change rate being less than or equal to a change rate threshold, it is determined that the reason for the overall resistance increase is that the overall resistance increases due to a temperature increase.

[0010] As a preferred technical solution of the USB flash drive hot-swap protection adaptive current control system, in response to the reason for the increase in the overall resistance being that the USB flash drive is unplugged, resulting in an increase in contact resistance, the release time of the USB flash drive reverse current is determined according to the overall resistance change rate, including: Obtaining the overall resistance change rate; Determining the complete detachment time of the USB flash drive according to the overall resistance change rate; Determining a release time of the reverse current according to the complete separation time; The value of the reverse current is calculated according to the charge amount and release time of the U disk capacitor.

[0011] As an optimal technical solution for the USB flash drive hot-swap protection adaptive current control system, the maximum current is corrected and data transmission is restarted. The storage unit stores the configuration information of the USB flash drive and the corrected current. The next time the USB flash drive is inserted, the corrected current is directly used for data transmission.

[0012] As a preferred technical solution for the USB flash drive hot-swap protection adaptive current control system, the complete detachment time of the USB flash drive is determined according to the overall resistance change rate, and is obtained by establishing a calibration database or a mathematical model through a limited number of plug-in experiments.

[0013] As an optimal technical solution for the USB flash drive hot-swap protection adaptive current control system, in response to the absence of historical data corresponding to the USB flash drive in the analysis module, the VID / PID is read and an independent configuration file is created, relevant data of the same type of USB flash drive is obtained, the current parameters are initialized based on the bMaxPower field and preset safety rules, and the learning mode is entered in the first N connections to calibrate the threshold.

[0014] As a preferred technical solution for the USB flash drive hot-swap protection adaptive current control system, the complete disengagement time is: the length of time from when the USB flash drive starts to be unplugged to when the contact area is reduced to the point where electrical conduction cannot be maintained.

[0015] Compared with the prior art, the beneficial effect of the present invention is that, on the one hand, at the moment of U disk access, the slope of the current curve is compared with the preset slope threshold, and when the slope is lower than the threshold, the wear coefficient is calculated according to the number of historical connections, the contact resistance and the slope, and the maximum allowable working current is dynamically adjusted, so as to ensure that the temperature of the U disk interface will not rise rapidly due to excessive current when the U disk interface is worn, thereby avoiding the accelerated aging of the U disk interface, thereby extending the service life of the U disk. On the other hand, during the data transmission process, if the overall change rate exceeds the change rate threshold, it indicates that the resistance change at this time has exceeded the range that can be affected by the wear of the U disk interface or the increase in resistance due to the increase in the temperature of the U disk, and it is determined that the U disk is in a state of being gradually unplugged. By combining the charge amount of the U disk capacitor and the maximum tolerance current, the release value of the reverse current is calculated, so that the residual charge of the capacitor is quickly discharged through the controllable switch circuit when the disk is unplugged, thereby avoiding the reverse current surge generated by the reverse current at the moment of the U disk being unplugged to damage the U disk, thereby further extending the service life of the U disk. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural block diagram of a U disk hot-swap protection adaptive current control system in an embodiment of the present invention; Figure 2 This is a flow chart of the steps of determining the release time of the reverse current of a USB flash drive according to the overall resistance change rate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0018] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0019] See also Figure 1 As shown, it is a structural block diagram of a USB flash drive hot-swap protection adaptive current control system according to an embodiment of the present invention, including: U disk, equipped with hot-swap protection unit; A detection module, which is connected to the USB flash drive and is used to detect the current and voltage of the USB flash drive in real time during operation; The analysis module is connected to the detection module and the USB flash drive and is equipped with an analysis unit and a storage unit, wherein: The storage unit is used to store the historical usage data of the USB flash drive, including: the USB flash drive information and its corresponding historical connection times, contact resistance and threshold standards for determination; The analysis unit is used to compare the slope of the current curve with the slope threshold when the USB flash drive is just connected, and in response to the slope being less than the slope threshold, correct the maximum current according to the wear coefficient; wherein the wear coefficient is determined according to the number of historical connections, the slope and the contact resistance; During data transmission, the overall resistance change rate is calculated and compared with the change rate threshold. In response to the overall resistance change rate being greater than the change rate threshold, the maximum value of the reverse current is determined based on the overall resistance change rate, the maximum current that the USB flash drive can withstand, and the charge of the USB flash drive capacitor.

[0020] Furthermore, the current curve is a curve about the current value drawn in a coordinate system where the ordinate is current and the abscissa is time.

[0021] During implementation, the detection module collects the current and voltage signals of the USB flash drive in real time through a high-precision analog-to-digital converter, with a sampling frequency of no less than 1kHz; the storage unit uses a non-volatile memory to record the information of the USB flash drive. Each piece of information of the USB flash drive corresponds to the number of historical connections, contact resistance, and the threshold standard used for judgment. Different USB flash drives have different values ​​for the judgment standard.

[0022] Specifically, on the one hand, at the moment the USB flash drive is connected, the analysis unit calculates the slope of the current curve (the amount of current change per unit time) in real time through the microprocessor and compares it with the preset slope threshold. If the slope is lower than the threshold, the wear coefficient is calculated based on the number of historical connections, contact resistance and slope, and the maximum allowable working current is dynamically adjusted to ensure that when the USB flash drive interface is worn, the heat of the interface will not accumulate rapidly in a short period of time due to the current rising too fast, thereby avoiding the accelerated aging of the USB flash drive interface and extending the service life of the USB flash drive. On the other hand, during the data transmission process, the analysis unit continuously calculates the overall resistance change rate (ΔR / R). If the overall change rate exceeds the change rate threshold, it indicates that the resistance change degree at this time has exceeded the resistance change degree during normal use (for example, the resistance increase caused by wear of the U disk interface, or the resistance increase caused by the increase in temperature of the U disk), and it is determined that the U disk is in a state of being gradually unplugged. By combining the charge amount and the maximum tolerance current of the U disk capacitor, the release value of the reverse current is calculated, so that the residual charge of the capacitor is quickly discharged through the controllable switch circuit when the disk is unplugged, thereby avoiding the reverse current surge generated at the moment the U disk is unplugged to damage the U disk, thereby further extending the service life of the U disk.

[0023] Specifically, the wear coefficient is proportional to the number of historical connections and the contact resistance, and inversely proportional to the slope.

[0024] In practice, the wear coefficient is set , where: C is the number of historical connections, R is the value of the contact resistance after the maximum-minimum normalization process, and S is the value of the current curve slope after the maximum-minimum normalization process. Among them, S+0.1 is to avoid the error of zero division caused by the denominator; the contact resistance can be calculated by measuring the voltage and current at both ends of the U disk interface and using Ohm's law. The calculation process belongs to the existing technology and will not be repeated here.

[0025] Furthermore, after the contact resistance and the slope of the current curve are calculated and normalized, they are both unitless, and the number of connections also has units. Therefore, the wear coefficient can be used as a dimension to evaluate the degree of wear. By calculating the wear coefficient, the wear of the USB flash drive connector is quantified. It can be understood that the greater the wear of the USB flash drive connector, the smaller the contact area and the greater the resistance. At this time, the original current will generate more heat, causing the USB flash drive connector to age faster. By calculating the wear coefficient, a basis is provided for subsequent current regulation, thereby further extending the service life of the USB flash drive.

[0026] Specifically, the slope of the current curve is compared with the slope threshold, and it is determined that the contact resistance meets the standard. In response to the slope being less than the slope threshold, the maximum current is corrected according to the wear coefficient, and the value of the corrected maximum current is negatively correlated with the wear coefficient. Or, in response to the slope being greater than or equal to a slope threshold, it is determined that the contact resistance meets the standard.

[0027] In implementation, the slope of the current curve should be controlled between 0.5 A / ms and 1 A / ms as much as possible. Preferably, the slope threshold is 0.7 A / ms.

[0028] Specifically, the maximum current is corrected according to the wear coefficient, and the value of the corrected maximum current is negatively correlated with the wear coefficient. An embodiment of the present invention provides a method for correcting the maximum current, including: If the wear coefficient is greater than the preset wear coefficient, the maximum current is corrected to a corresponding value using the first correction coefficient; If the wear coefficient is less than or equal to the preset wear coefficient, the maximum current is corrected to a corresponding value using a second correction coefficient; In practice, the value standard of the preset wear coefficient is: the wear coefficient corresponding to the oxidation speed of the connector when the USB flash drive is in normal working condition and working temperature and meets the standard; preferably, the preset wear coefficient is 400. Except for some high-performance USB flash drives, the working current of ordinary USB flash drives is generally between 50mA and 100mA. In the embodiment of the present invention, the maximum current is 80mA, and the correction coefficient is in the range of 0.625-1. The values ​​of the first correction coefficient and the second correction coefficient must also meet the premise that the value of the corrected maximum current is negatively correlated with the wear coefficient. Preferably, the first correction coefficient is 0.7 and the second correction coefficient is 0.8.

[0029] Specifically, the present invention adjusts the maximum current through the wear coefficient, thereby ensuring that data transmission is ensured while ensuring that the maximum current does not generate a lot of heat when flowing through the USB flash drive interface, thereby protecting the USB flash drive connector and further extending the service life of the USB flash drive.

[0030] In detail, in response to the maximum current being corrected according to the wear coefficient, data transmission is suspended and after waiting for all cached data to be stored in the USB storage medium, the maximum current is corrected and data transmission is restarted.

[0031] Specifically, when the current correction is triggered, the microprocessor sends a pause command to the USB controller, waiting for the cached data to be written to the USB flash drive storage chip, and then adjusts the maximum current value of the current limiting circuit through the digital-to-analog converter (DAC), and then resumes data transmission. This ensures that the cached data is completely written before the current is reduced, thereby avoiding data loss due to a sudden drop in current during the storage process while protecting the interface circuit, thereby further extending the service life of the USB flash drive.

[0032] Specifically, the overall resistance change rate is calculated and compared with the change rate threshold, and the reason for the increase in overall resistance is determined according to the comparison result, including: In response to the overall resistance change rate being greater than the change rate threshold, determining that the reason for the overall resistance increase is that the contact resistance increases due to the USB flash drive being pulled out; In response to the overall resistance change rate being less than or equal to the change rate threshold, it is determined that the cause of the overall resistance increase is that the overall resistance increases due to a temperature increase.

[0033] Specifically, during the operation of the USB flash drive, the resistance will increase slightly due to heat. The selection of the change rate threshold can be measured through a limited number of experiments or directly calculated based on physical principles. For example, based on electrical principles and the physical structure of the USB flash drive, a theoretical model of the resistance change of the USB flash drive during the plug-in process and temperature changes is established. The resistance change is calculated according to the temperature coefficient formula of the resistance, and the maximum value of the resistance increase caused by temperature change is preferentially selected. In practical applications, the resistance change rate caused by the material and temperature fluctuation range is usually between 10% and 15%. Preferably, the change rate threshold selection standard is 13%.

[0034] In detail, during the physical unplugging process, the contact area at the USB flash drive connector decreases rapidly, causing the contact resistance to increase rapidly, and then causing the overall resistance to increase rapidly. The rate of resistance increase is much faster than the rate of resistance increase caused by the heat generated during the storage process of the USB flash drive. Based on this principle, the present invention calculates the overall resistance change rate and compares it with the change rate threshold, so as to quickly determine the cause of the resistance increase. When the determination result is that the USB flash drive is in the process of being unplugged, the USB flash drive circuit is protected by subsequently limiting the reverse current, thereby further extending the service life of the USB flash drive.

[0035] Specifically, the reason for the increase in overall resistance is that the USB flash drive is unplugged, which causes the contact resistance to increase. Figure 2 As shown, it is a flowchart of the steps of determining the release time of the reverse current of the USB flash drive according to the overall resistance change rate according to an embodiment of the present invention, including: Step S1, obtaining the overall resistance change rate; Step S2, determining the complete detachment time of the USB flash drive according to the overall resistance change rate; Step S3, determining the release time of the reverse current according to the complete separation time; Step S4, calculating the value of the reverse current according to the charge amount and release time of the USB disk capacitor.

[0036] It can be understood that the complete detachment time of the U disk is proportional to the extraction speed. During the extraction process, the U disk is gradually pulled out, the contact area gradually decreases, and the resistance of the contact part gradually increases. Therefore, the extraction speed is also proportional to the overall resistance change rate. Therefore, the complete detachment time of the U disk can be obtained by a pre-established calibration database or a mathematical model. The analysis unit inputs the current value of the overall resistance change rate to obtain the corresponding complete detachment time of the U disk. The modeling or calibration database establishment process are all existing technologies and will not be repeated here.

[0037] In the above technical solution, it can be understood that the release time of the reverse current is less than or equal to the complete detachment time, so as to ensure that the current can be completely extracted before the USB flash drive is completely detached. Preferably, the release time of the reverse current is 60% of the complete detachment time. On the premise that the charge amount of the reverse current and the release time of the reverse current have been determined, the value of the reverse current can be calculated according to charge amount = current × time.

[0038] Specifically, in response to the absence of historical data corresponding to the USB flash drive in the analysis module, the VID / PID is read and an independent configuration file is created, relevant data of the same type of USB flash drive is obtained, and the current parameters are initialized based on the bMaxPower field and preset safety rules. Preferably, the initialization current parameter is set to 80% of bMaxPower, and the data generated in the first N connections are input into the learning model to calibrate the corresponding threshold standard. The use of the learning model and the training of the data are both existing technologies and will not be elaborated here. Preferably, the value of N is 5.

[0039] Furthermore, the complete separation time is the time length from when the USB flash drive starts to be pulled out to when the contact area is reduced to the point where electrical conduction cannot be maintained.

[0040] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. U disk hot plug protection adaptive current control system, characterized in that: include: U disk, equipped with hot-swap protection unit; A detection module, which is connected to the USB flash drive and is used to detect the current and voltage of the USB flash drive in real time during operation; An analysis module, which is connected to the detection module and the USB flash drive, is configured with an analysis unit and a storage unit, wherein: The storage unit is used to store historical usage data of the USB flash drive, including: USB flash drive information and its corresponding historical connection times, contact resistance, and threshold standards for determination; The analysis unit is used to compare the slope of the current curve with the slope threshold when the USB flash drive is just connected, and in response to the slope being less than the slope threshold, correct the maximum current according to the wear coefficient; wherein the wear coefficient is determined according to the number of historical connections, the slope and the contact resistance; During data transmission, the overall resistance change rate is calculated and compared with the change rate threshold. In response to the overall resistance change rate being greater than the change rate threshold, the maximum value of the reverse current is determined based on the overall resistance change rate, the maximum current that the U disk can withstand, and the charge of the U disk capacitor.

2. The USB hot-swap protection adaptive current control system according to claim 1, characterized in that: The wear coefficient is positively correlated with the historical connection times and the contact resistance, and negatively correlated with the slope.

3. The USB hot-swap protection adaptive current control system according to claim 2, characterized in that: The slope of the current curve is compared with a slope threshold value to determine whether the contact resistance meets the standard, and in response to the slope being less than the slope threshold value, the maximum current is corrected according to the wear coefficient, and the value of the corrected maximum current is negatively correlated with the wear coefficient; Or, in response to the slope being greater than or equal to the slope threshold, it is determined that the contact resistance meets a standard.

4. The USB hot-swap protection adaptive current control system according to claim 3 is characterized in that: In response to the correction of the maximum current according to the wear coefficient, data transmission is suspended and after all cached data is stored in the USB storage medium, the maximum current is corrected and data transmission is restarted.

5. The USB hot-swap protection adaptive current control system according to claim 4, characterized in that: The calculating the overall resistance change rate and comparing it with the change rate threshold, and determining the cause of the overall resistance increase according to the comparison result, comprises: In response to the overall resistance change rate being greater than a change rate threshold, determining that the reason for the overall resistance increase is that the contact resistance increases due to the USB flash drive being pulled out; In response to the overall resistance change rate being less than or equal to a change rate threshold, it is determined that the reason for the overall resistance increase is that the overall resistance increases due to a temperature increase.

6. The USB hot-swap protection adaptive current control system according to claim 5, characterized in that: In response to the reason for the increase in the overall resistance being that the contact resistance increases due to the USB flash drive being pulled out, determining the release time of the USB flash drive reverse current according to the overall resistance change rate, including: Obtaining the overall resistance change rate; Determining the complete detachment time of the USB flash drive according to the overall resistance change rate; Determining a release time of the reverse current according to the complete separation time; The value of the reverse current is calculated according to the charge amount and release time of the U disk capacitor.

7. The USB hot-swap protection adaptive current control system according to claim 4, characterized in that: The maximum current is corrected and data transmission is restarted, the storage unit stores the configuration information of the USB flash drive and the corrected current, and the corrected current is directly used for data transmission next time the USB flash drive is inserted.

8. The USB hot-swap protection adaptive current control system according to claim 6, characterized in that: The complete detachment time of the USB flash drive is determined according to the overall resistance change rate, and is obtained by establishing a calibration database or a mathematical model through a limited number of plug-in and unplug experiments.

9. The USB hot-swap protection adaptive current control system according to claim 6, characterized in that: The complete disengagement time is the time length from when the USB flash drive starts to be pulled out to when the contact area is reduced to the point where electrical conduction cannot be maintained.

10. The USB flash drive hot-swap protection adaptive current control system according to claim 1, characterized in that: In response to the absence of historical data corresponding to the USB flash drive in the analysis module, the VID / PID is read and an independent configuration file is created, relevant data of the same type of USB flash drive is obtained, current parameters are initialized based on the bMaxPower field and preset safety rules, and a learning mode is entered in the first N connections to calibrate the corresponding threshold standard.

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