Charging method and system for Bluetooth earphone charging box

Abstract

The invention relates to the technical field of electronic equipment charging management, and particularly discloses a Bluetooth earphone charging box charging method and system, and the method comprises the steps: periodically obtaining a charging contact actual measurement impedance value and an earphone battery parameter; a contact quality factor is calculated by analyzing an impedance value and a battery parameter change trend, time decay weighting is carried out on a historical sequence of the contact quality factor to generate a state prediction value, then the prediction value and a measured value are fused in a self-adaptive mode, and a filtering impedance value is output to filter instantaneous interference; in the sliding time window, comparing the filtering impedance value with a preset reference range, and comprehensively calculating an out-of-limit time ratio, an instantaneous variable quantity and a range in the window so as to identify a stable contact state or an unstable fluctuation state; executing control according to an identification result: in a stable state, fully charging, namely physically powering off; when the state is identified as an unstable fluctuation state, entering a contact protection mode through a multi-stage confirmation process, and only recovering after the connection is continuously stable; the charging reliability and safety are improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] This invention relates to the field of electronic device charging management technology, and specifically to a charging method and system for a Bluetooth headset charging case. Background Technology

[0002] With the widespread adoption of wireless audio devices, Bluetooth earphones and their charging cases have become a common combination in daily life. The charging case provides charging for the earphones through a built-in battery and metal charging contacts. Current mainstream charging solutions rely on intelligent sensing elements (such as voltage and current detection circuits) to monitor the charging circuit status, and combine this with a battery management chip to implement conventional protections such as overcharging and overheating.

[0003] However, in usage scenarios such as sports and humidity, electrolytes such as sweat crystallize at the charging contacts, causing dynamic and random abrupt changes in contact impedance. The sensing elements in existing technologies typically only provide static or slowly changing parameter measurements (such as average impedance and instantaneous voltage), and their subsequent processing logic is relatively simple, mostly based on comparisons using fixed thresholds. This makes it difficult for the system to distinguish between normal charging states and abnormal contact states with high-frequency fluctuations caused by crystallization contamination. Specifically, instantaneous impedance jumps caused by contamination can easily be misinterpreted as headphone plugging and unplugging operations, resulting in the charging circuit being repeatedly and incorrectly switched on and off, generating current surges. This not only damages battery life but also poses safety hazards. Summary of the Invention

[0004] The purpose of this invention is to provide a charging method and system for a Bluetooth headset charging case to solve the problems mentioned above.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for charging a Bluetooth earphone charging case includes the following steps: S1: When the charging case and earphones are connected, periodically obtain the measured impedance value of the charging contacts and the battery parameters of the earphones; S2: By collaboratively analyzing the changing trend of the measured impedance value and the corresponding relationship with the battery parameters, the true impedance state of the charging contact is dynamically estimated, and the filtered impedance value is output. S3: Based on the variation characteristics of the filter impedance value over a continuous time period, compare the filter impedance value with the preset impedance reference range, calculate the change in the filter impedance value within the sliding time window, and identify the contact state of the charging contacts. S4: Based on the identified contact state, control the charging operation of the charging case to the earphones; when a stable contact state is identified and the earphone battery is fully charged, perform a physical disconnection operation of the charging circuit; when an unstable fluctuation state is identified, suppress or stop the charging start command triggered by the instantaneous change of the measured impedance value.

[0006] As a further aspect of the present invention: S2 specifically includes: S21: Based on the measured impedance value of the current cycle and the battery parameters at the same time, the contact quality factor characterizing the contact reliability is calculated by analyzing the correlation between the measured impedance value and the changes in battery parameters. S22: Using contact quality factors from multiple periods in the historical sequence, a weighted average of the contact quality factors is used to generate a predicted value of the contact state. S23: Based on the degree of deviation between the predicted contact state value and the current measured impedance value, adjust the confidence weight of the predicted value, and merge the weighted predicted value with the measured impedance value to output the filtered impedance value for the current cycle.

[0007] As a further aspect of the present invention: S21 specifically includes: Compare the current measured impedance value with the measured impedance value of the previous cycle to calculate the direction of change; At the same time, the battery parameters of the current cycle are compared with those of the previous cycle to calculate the direction of change; If the two change in opposite directions, it is determined that there is a normal charging physical process, and the first intermediate factor is output. If the two change in the same direction, it is determined that there is contact abnormal interference that is not part of the charging process, and the second intermediate factor is output. The value of the first intermediate factor is greater than that of the second intermediate factor; Obtain the sequence of changes in the measured impedance value over multiple consecutive historical periods, and calculate the stability metric of the sequence of changes. The contact quality factor is obtained by multiplying the intermediate factor output from the first step with the stability metric output from the second step.

[0008] As a further aspect of the present invention: S22 specifically includes: Obtain the contact quality factors, including the current cycle and a preset number of previous cycles, to form a historical factor sequence; Assign a time decay weight to each contact quality factor in the historical factor sequence; The contact quality factor is multiplied by the corresponding time decay weight in the historical factor sequence and summed. The sum is then divided by the sum of all weight values, and the resulting quotient is the predicted contact state value.

[0009] As a further aspect of the present invention: S23 specifically includes: Calculate the absolute difference between the predicted contact condition value and the current measured impedance value; Based on the absolute difference, the trust weight of the predicted value for the current period is determined by querying the preset mapping relationship. The predicted contact state value is multiplied by the trust weight to obtain the predicted contribution value; at the same time, the current measured impedance value is multiplied by the remainder after subtracting the trust weight to obtain the measured contribution value. The predicted contribution value is added to the measured contribution value, and the sum is the filter impedance value for the current cycle.

[0010] As a further aspect of the present invention: S3 specifically includes: Within the sliding time window, the ratio of the cumulative duration during which the statistical filter impedance value exceeds the impedance reference range to the total duration of the sliding time window is used as the over-limit time ratio. Within the sliding time window, the difference between the maximum and minimum values ​​of the filter impedance is calculated and used as the range within the window. When the filter impedance value is within the impedance reference range, the change is less than the preset stability threshold, and the range within the window is less than the first preset range threshold, it is identified as a stable contact state. When the over-limit time ratio is greater than the preset ratio threshold, the change is greater than the preset fluctuation threshold, and the range within the window is greater than the second preset range threshold, it is identified as an unstable fluctuation state; the second preset range threshold is greater than the first preset range threshold.

[0011] As a further aspect of the present invention: the suppression or cessation of the charging start command triggered by the instantaneous change in the measured impedance value specifically includes: Enter contact protection mode, which blocks all charging start requests triggered by drops in measured impedance value; In contact protection mode, the filter impedance value is continuously detected, and the current contact state is re-identified according to the method in step S3. If the stable contact state is re-identified, the stable continuous timer is started; if the unstable fluctuation state is re-identified, the stable continuous timer is reset and an unstable feature counter is incremented. The logic for exiting the contact protection mode and resuming normal charging state is determined only when the stable continuous timer's count exceeds the first preset duration and the unstable feature counter does not increase during this period.

[0012] As a further aspect of the present invention: the process of entering the contact protection mode is as follows: The first step is to start the fluctuation confirmation timer when the fluctuation is first identified as unstable. The second step is to continuously re-identify the contact state according to the method in step S3 within the timing cycle of the fluctuation confirmation timer. The third step is to determine if the number of times an unstable fluctuation state is re-identified within the fluctuation confirmation timer's time period reaches the preset threshold, and then proceed to the fourth step; otherwise, exit the process and return to normal. The fourth step is to save the charging operation status before entering the circuit and set the contact protection mode flag to block all charging start commands triggered by instantaneous changes in the measured impedance value.

[0013] A Bluetooth earphone charging case charging system, comprising: The parameter acquisition module periodically acquires the measured impedance value of the charging contacts and the battery parameters of the earphones when the charging case and earphones are connected. The dynamic estimation module dynamically estimates the true impedance state of the charging contacts by collaboratively analyzing the changing trend of the measured impedance value and the corresponding relationship with the battery parameters, and outputs the filtered impedance value. The status recognition module compares the filter impedance value with a preset impedance reference range based on the change characteristics of the filter impedance value over a continuous time period, and calculates the change in the filter impedance value within the sliding time window to identify the contact status of the charging contacts. The charging control module controls the charging operation of the charging case to the earphones based on the identified contact state. When a stable contact state is identified and the earphone battery is fully charged, the charging circuit is physically disconnected. When an unstable fluctuation state is identified, the charging start command triggered by the instantaneous change of the measured impedance value is suppressed or stopped.

[0014] The beneficial effects of this invention are: (1) This invention accurately identifies unstable fluctuation states caused by contamination such as electrolyte crystallization, and intelligently suppresses charging commands falsely triggered by impedance jumps in this state, thus blocking repeated current surges generated during the "virtual disconnection-reconnection" process. This avoids the headphone battery from being subjected to abnormally high-frequency and irregular charge-discharge cycles when it is fully charged, reduces the electrochemical stress of the battery, and thus effectively delays the battery capacity decay.

[0015] (2) This invention, through dynamic estimation, state recognition, and multi-level confirmation protection mechanisms, enables the charging system to possess intelligent fault tolerance and adaptive management capabilities against the deterioration of the physical state of the contacts (such as sweat corrosion). This ensures that the charging process remains stable and reliable even in harsh environments such as motion and humidity, without accidentally triggering protection or interrupting charging due to brief disturbances, nor entering an oscillating charging mode due to continuous contamination. Users can obtain a stable charging experience without frequently cleaning the contacts, reducing the inconvenience caused by charging failures and improving the overall durability of the product and user satisfaction. Attached Figure Description

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system block diagram of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1 As shown, the present invention provides a charging method for a Bluetooth earphone charging case, comprising the following steps: S1: When the charging case and earphones are connected, periodically obtain the measured impedance value of the charging contacts and the battery parameters of the earphones; S2: By collaboratively analyzing the changing trend of the measured impedance value and the corresponding relationship with the battery parameters, the true impedance state of the charging contact is dynamically estimated, and the filtered impedance value is output. S3: Based on the variation characteristics of the filter impedance value over a continuous time period, compare the filter impedance value with the preset impedance reference range, calculate the change in the filter impedance value within the sliding time window, and identify the contact state of the charging contacts. S4: Based on the identified contact state, control the charging operation of the charging case to the earphones; when a stable contact state is identified and the earphone battery is fully charged, perform a physical disconnection operation of the charging circuit; when an unstable fluctuation state is identified, suppress or stop the charging start command triggered by the instantaneous change of the measured impedance value.

[0020] In S1, after the charging case and earphones establish an electrical connection through the charging contacts, the control unit inside the charging case begins to periodically perform parameter acquisition operations at preset fixed time intervals. The measured impedance value is obtained by applying a small-amplitude test current signal with a constant amplitude between the contacts in the charging circuit, and simultaneously measuring the voltage response generated across the contacts at this time with high precision, and calculating the impedance value at that moment based on Ohm's law.

[0021] The earphone's battery parameters, primarily including the real-time terminal voltage and charging current, are synchronously acquired by the battery management chip inside the charging case. The battery management chip, through its internal analog-to-digital converter, measures the voltage on the monitoring lines connected to the positive and negative terminals of the earphone battery, as well as the voltage across the precision sampling resistor connected in series in the charging circuit, thereby directly obtaining the required battery parameter values. These measured impedance values ​​and battery parameters are simultaneously read and stored for use in subsequent processing steps.

[0022] The core objective of step S2 is to dynamically estimate the true state of the charging contacts by performing in-depth processing on the periodically acquired raw data, and output a filtered impedance value that effectively reflects the trend and filters out transient interference. This step sequentially executes the following three sub-steps, gradually transforming the raw measured data into a reliable basis for decision-making.

[0023] S21: Calculate the contact quality factor: This step aims to assess the reliability of the current contact based on data from the current cycle and the previous cycle. First, calculate the direction of change of the measured impedance value and battery parameters. Let the current cycle be denoted as... The actual measured impedance value is At the same time, the battery parameters (such as battery voltage) are Previous cycle The corresponding value is and Calculate the direction of change of the measured impedance value. :like ,but Recorded as "increase"; if If the change is greater than or equal to the change, it is recorded as "decreased"; if the change is equal, it is recorded as "unchanged". Similarly, the direction of change in battery parameters is calculated. .

[0024] According to the laws of physics, during normal charging, as the battery charge increases, its terminal voltage... It should show an upward trend ( (For "increase"), and due to the relative stability of the battery's internal resistance and the total circuit resistance, the measured contact point impedance The impedance should remain relatively stable or change only slightly with temperature rise. If the contact point becomes unstable due to crystallization contamination, its impedance value will... Dramatic and unpredictable jumps may occur. Therefore, through analysis... and The correlation can be used to preliminarily determine the source of interference: if and If the directions are opposite (e.g., impedance decreases as voltage increases), this conforms to the physical characteristics of a normal charging circuit and ensures high contact reliability; if the directions are the same (e.g., impedance also increases abnormally as voltage increases), there is a high probability of abnormal contact interference caused by factors other than the charging process.

[0025] Therefore, two intermediate factor values ​​are set: the first intermediate factor. (Corresponding to the normal charging process) and the second intermediate factor (Corresponding to abnormal contact interference), and it is stipulated that For example, it can be set , The output rule for intermediate factors is: if and If the direction is opposite, then the output will be... If the directions are the same, then output... If either direction is "unchanged", then a conservative output can be made. Or one between and The middle value between.

[0026] Next, the stability of the measured impedance value in the short term is evaluated. Data including the current period and previous consecutive periods is obtained. One cycle (e.g.) The measured impedance value of ) forms a length of The sequence. Calculate the absolute value of the change in impedance between adjacent periods in this sequence. This stability metric By calculating the change series It is characterized by the reciprocal of the coefficient of variation (the ratio of standard deviation to mean). The calculation process can be described in words as follows: First, calculate the series of changes... The average of all elements Then calculate the standard deviation of the sequence. Finally, the stability metric is calculated. The smaller the fluctuation in the change (the more stable), Compared to The smaller, The larger the value, the greater the fluctuation. The smaller the value.

[0027] Finally, the intermediate factor output from the first step... (Values) or The stability metric obtained in the second step is compared with the stability metric calculated in the second step. Multiply to obtain the contact quality factor for this period. ,Right now This factor combines trend correlation and short-term volatility; a higher value indicates a more reliable and stable current contact.

[0028] S22: Generate contact state prediction values. This step utilizes the historical sequence of contact quality factors to predict the contact state trend at the next moment. Essentially, it is a weighted averaging process that considers time decay. First, obtain a continuous... One cycle (e.g.) The historical factor sequence consisting of the contact quality factors of ) is denoted as .

[0029] Then, a time-decaying weight is assigned to each factor in this sequence. The principle of weight allocation is to give higher weight to recent data to reflect state changes more quickly. One specific implementation is to use linearly decreasing weights: Let the first... Factors ( from arrive The weights (corresponding to the weights tracing back from the current period) For example, when At that time, the current cycle weight Previous cycle weight And so on, the earliest period Weight .

[0030] Finally, the predicted contact state value is calculated. The calculation formula is as follows: The numerator is the sum of the products of each contact quality factor in the historical factor sequence and its corresponding time decay weight; the denominator is the sum of all time decay weights. The result of this formula is a weighted average, which is more dominated by recent contact quality factors, thus achieving a smooth prediction of future trends in contact conditions.

[0031] S23: Fusion Output Filter Impedance Value: This step adaptively fuses the predicted value obtained in sub-step S22 with the measured value of the current cycle to obtain the final filter impedance value. First, calculate the predicted value of the contact state. Compared with the current measured impedance value absolute difference .

[0032] Then, based on this absolute difference The confidence weight of the predicted value for the current period is determined by querying a preset mapping relationship. The mapping relationship is configured as follows: The smaller the value, the closer the predicted value is to the measured value, and the more reliable the prediction. The higher the value, the better; conversely, The larger the value, the more likely there are unpredictable mutations, and the more trust should be placed in the measured values. The lower the value, the better. This mapping relationship can be implemented using a piecewise linear function or a lookup table. For example, two thresholds can be set. and :when hour, (e.g., 0.9); when hour, (e.g., 0.1); when hour, exist and Linear interpolation between them.

[0033] Obtain trust weight Then, the predicted contribution value and the measured contribution value are calculated separately. The predicted contribution value is the predicted value. With trust weight The product of: The measured contribution value is the actual measured value. With residual weight The product of.

[0034] Finally, the predicted contribution value is added to the measured contribution value, and the sum is the filter impedance value for the current cycle. Its calculation expression is: Through the above calculations, when the measured value undergoes a stable change consistent with historical trends, the filtered value will smoothly follow it; when the measured value experiences an abnormal, drastic change with a large deviation from the prediction (possibly caused by crystal bridging), the filtered value will retain more of the abrupt change information in the measured value, but will adjust the weighting. The adjustment can still play a certain role in smoothing and suppressing, providing a more interference-resistant input signal for subsequent state recognition steps.

[0035] The core task of step S3 is to accurately identify the current physical contact state of the charging contacts by analyzing the dynamic behavior characteristics of the filtered impedance value output in step S2 over a continuous time period. This state is the direct basis for subsequent charging control decisions. The identification process is carried out within a continuously sliding fixed-duration window, for example, a total window duration of 3 seconds, containing multiple consecutive sampling cycles (e.g., 10 cycles per second, then the window contains 30 filtered impedance value data points). This step specifically executes the following logic: An impedance reference range needs to be preset, representing a reasonable range of normal fluctuation in the filter impedance value under ideal clean contact conditions. This range can be obtained through the initial learning phase: when the earphones are first paired with the charging case and good contact is confirmed, the filter impedance value is continuously collected for a period of time, and its average value μ and standard deviation σ are calculated. Then, the lower limit of the impedance reference range is set to μ minus 3 times σ, and the upper limit is set to μ plus 3 times σ. In subsequent recognition processes, the real-time filter impedance value is compared with this preset range to determine whether it "exceeds the limit".

[0036] Two key statistical characteristics are calculated. The first characteristic is the over-limit time ratio. Within the sliding time window, the filter impedance value at each sampling point is assessed. If the value is lower than the lower limit of the impedance reference range or higher than the upper limit, that point is recorded as an "over-limit point." The number of all "over-limit points" within the window is counted, and this number is multiplied by the time of a single sampling period to obtain the cumulative duration for which the filter impedance value exceeds the reference range. This cumulative duration is divided by the total duration of the sliding time window, and the resulting ratio is the over-limit time ratio. The second characteristic is the range within the window. Within the same sliding time window, the maximum and minimum values ​​of all filter impedance values ​​are identified. The difference between the maximum and minimum values ​​is the range within the window.

[0037] Based on the characteristics of the filter impedance value within the sliding window, the system divides the contact state into three categories: (1) Stable contact state: must simultaneously satisfy "filter impedance value within the reference range, instantaneous change ≤ stable threshold, range within the window ≤ first range threshold"; (2) Unstable fluctuation state: must simultaneously satisfy "over-limit time ratio > proportional threshold, instantaneous change > fluctuation threshold, range within the window > second range threshold".

[0038] Differentiated control is implemented for different states: (1) In a stable state, regular charging management is performed, and the power is physically cut off after the battery is fully charged; (2) In an unstable fluctuating state, the system immediately enters "contact protection mode" to block charging commands triggered by impedance switching, and can only be restored after the stable conditions are met continuously. This design realizes a complete closed loop from state recognition to control execution, which improves the adaptability and reliability of the system in complex scenarios such as pollution.

[0039] The core task of step S4 is to execute the corresponding charging control logic based on the contact state identified in step S3. The key is to implement differentiated management strategies according to different contact states to complete the charging process while ensuring charging safety and battery life. The specific execution logic of this step consists of two main parts: the first part is to perform routine charging management and power-off when fully charged based on a stable contact state; the second part is to activate and execute a multi-level confirmation contact protection mode process for unstable and fluctuating states.

[0040] Part 1: Standard Charging Management and Power-Off Upon Full Charge. When the contact state identified in step S3 is "stable contact state," it indicates that the charging contacts are reliably connected and the electrical parameters are normal. In this state, the charging control logic determines the charging stage based on the earphone's battery parameters (such as voltage and current). Standard charging management methods are used, such as constant current followed by constant voltage charging, until the earphone battery is determined to be fully charged. The criteria for determining if the battery is fully charged can be based on the battery voltage reaching its charging termination voltage and the charging current decreasing to a preset cutoff current threshold. Once the battery is determined to be fully charged, the control logic immediately sends a shutdown command to the power switching device (such as a MOSFET) in the charging circuit, executing a physical disconnection operation of the charging circuit, completely cutting off the energy transfer path from the charging case to the earphone battery, thereby preventing overcharging and extending battery life.

[0041] Part Two: Activation and Execution of Contact Protection Mode. When step S3 first identifies the contact state as "unstable fluctuation state," it does not immediately trigger extreme protection actions. Instead, it initiates a "enter contact protection mode" process designed to avoid misjudgments and confirm risks. This process includes four sequential steps: The first step is to start a fluctuation confirmation timer. The timing period of this timer is set to a short time window, such as 0.5 seconds.

[0042] The second step is to continue to re-identify the contact state based on the latest filter impedance value data within this timing period, using the method described in step S3.

[0043] The third step involves statistical analysis at the end of the fluctuation confirmation timer's cycle. This counts the number of times the state was re-identified as "unstable fluctuation" within that cycle. If this count reaches or exceeds a preset threshold (e.g., 3 times within 0.5 seconds), a sustained instability risk is determined, meeting the conditions for entering "contact protection mode," and the process continues to the fourth step. If the threshold is not reached, it is determined to be a momentary interference or misjudgment, and the process exits, reverting to normal charging state logic.

[0044] The fourth step is to formally enter the "contact protection mode." First, the charging operation state just moments before entering this mode is saved (e.g., whether it is charging or idle). Then, a clear "contact protection mode flag" is set in the software logic. When this flag is set to an active state, its core function is to instruct subsequent logic to block all charging start requests triggered by instantaneous drops in the measured impedance value. This means that even if the measured impedance value subsequently changes drastically due to crystal bridging or other reasons, simulating an electrical signal similar to "earphone disconnected and then connected," the charging control logic will ignore such signals and will not initiate the charging process accordingly.

[0045] After entering "contact protection mode", the system is not completely static, but executes a dynamic monitoring and exit judgment process: First, in this mode, the system continues to periodically detect the filter impedance value and re-identify the current contact state according to the method in step S3.

[0046] Secondly, two auxiliary judgment variables are established: a stable continuous timer and an unstable feature counter. If the re-identification result is "stable contact state", the stable continuous timer is started (or continues to run) to begin accumulating time; if the re-identification result is "unstable fluctuation state" again, the stable continuous timer is immediately reset to zero, and the value of the unstable feature counter is incremented by one.

[0047] Finally, strict conditions are set for exiting the protection mode. The system will only exit "contact protection mode" if both of the following conditions are met simultaneously: Condition 1, the cumulative count of the stable continuous timer exceeds a first preset duration (e.g., set to 5 seconds); Condition 2, the value of the unstable characteristic counter does not increase during the entire period from the start of the stable continuous timer until the first preset duration is reached. After the exit conditions are met, the system clears the "contact protection mode flag," restores the saved or recalculated normal charging state logic based on the current battery state, and resets the unstable characteristic counter. If the exit conditions are not met, the system will continue to monitor in protection mode.

[0048] Through the above design, step S4 achieves intelligent fault-tolerant control of the charging process. It ensures efficient charging and safe power-off during stable connections; when dangerous oscillations caused by contact contamination are detected, it reliably enters a protection state through a multi-level confirmation mechanism, and only returns to normal after the connection stability has been fully and continuously verified. This fundamentally avoids repeated impacts on the battery and circuitry caused by "virtual disconnection and reconnection surges," significantly improving the system's robustness and safety under harsh operating environments.

[0049] Please see Figure 2 As shown, a Bluetooth earphone charging case charging system includes: The parameter acquisition module periodically acquires the measured impedance value of the charging contacts and the battery parameters of the earphones when the charging case and earphones are connected. The dynamic estimation module dynamically estimates the true impedance state of the charging contacts by collaboratively analyzing the changing trend of the measured impedance value and the corresponding relationship with the battery parameters, and outputs the filtered impedance value. The status recognition module compares the filter impedance value with a preset impedance reference range based on the change characteristics of the filter impedance value over a continuous time period, and calculates the change in the filter impedance value within the sliding time window to identify the contact status of the charging contacts. The charging control module controls the charging operation of the charging case to the earphones based on the identified contact state. When a stable contact state is identified and the earphone battery is fully charged, the charging circuit is physically disconnected. When an unstable fluctuation state is identified, the charging start command triggered by the instantaneous change of the measured impedance value is suppressed or stopped.

[0050] The working principle of this invention is as follows: First, the measured impedance values ​​of the charging contacts and the parameters of the earphone battery are periodically collected. Then, the contact quality factor is calculated by analyzing the correlation between the impedance value and the direction of change of the battery parameters. Based on the historical sequence of this factor, time decay weighting is performed to generate a predicted contact state value. Finally, the predicted value and the measured value are adaptively fused according to the degree of deviation, and a filtered impedance value that can filter out instantaneous interference is output. Next, the filtered impedance value is compared with a preset reference range within a sliding time window, and its over-limit time ratio, instantaneous change amount, and range within the window are comprehensively calculated to accurately identify a stable contact state or an unstable fluctuation state. Finally, the corresponding charging control is executed according to the identification result: when the battery is fully charged in a stable contact state, the power is physically cut off. When an unstable fluctuation state is identified, a multi-level process including fluctuation confirmation timing, state re-identification, and counting judgment is used to enter the contact protection mode. In this mode, the charging command triggered by the instantaneous change of impedance is blocked. The protection is exited and the normal charging logic is restored only when the connection is restored to a stable state. This effectively prevents the phenomenon of "virtual disconnection and reconnection surge" caused by contact contamination, and improves the charging safety and reliability.

[0051] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A Bluetooth earphone charging box charging method, characterized in that, The method comprises the following steps: S1: periodically obtaining the measured impedance value of the charging contact and the battery parameter of the earphone when the charging box and the earphone are in a connected state; S2: dynamically estimating the real impedance state of the charging contact by cooperatively analyzing the change trend of the measured impedance value and the corresponding relationship of the battery parameter, and outputting a filtered impedance value; S3: comparing the filtered impedance value with a preset impedance reference range according to the change characteristics of the filtered impedance value in continuous time, calculating the change amount of the filtered impedance value in a sliding time window, and identifying the contact state of the charging contact; S4: controlling the charging operation of the charging box on the earphone according to the identified contact state; when the stable contact state is identified and the earphone battery is fully charged, the physical disconnection operation of the charging loop is performed; when the unstable fluctuation state is identified, the charging start instruction triggered based on the instantaneous change of the measured impedance value is inhibited or stopped.

2. The charging method of the Bluetooth earphone charging box according to claim 1, characterized in that, The S2 specifically comprises: S21: based on the measured impedance value of the current period and the battery parameter at the same time, the correlation between the measured impedance value and the change of the battery parameter is analyzed to calculate a contact quality factor representing the contact reliability; S22: using the contact quality factors of multiple periods in the historical sequence, a contact state prediction value is generated by performing a weighted average operation on the contact quality factors; S23: according to the deviation degree of the contact state prediction value and the current measured impedance value, the trust weight of the prediction value is adjusted, and the weighted prediction value is fused with the measured impedance value to output the filtered impedance value of the current period.

3. The charging method of the Bluetooth earphone charging box according to claim 2, characterized in that, The S21 specifically comprises: comparing the current measured impedance value with the measured impedance value of the last period to calculate the change direction; at the same time, the battery parameter of the current period is compared with the battery parameter of the last period to calculate the change direction; if the change directions are opposite, it is determined that there is a normal charging physical process, and a first intermediate factor is outputted; if the change directions are the same, it is determined that there is a contact abnormal interference of non-charging process, and a second intermediate factor is outputted; the numerical value of the first intermediate factor is greater than that of the second intermediate factor; obtaining the change amount sequence of the measured impedance value in continuous multiple historical periods, and calculating the stability measure value of the change amount sequence; multiplying the intermediate factor outputted in the first step with the stability measure value outputted in the second step to obtain the contact quality factor.

4. The charging method of the Bluetooth earphone charging box according to claim 2, characterized in that, The S22 specifically comprises: obtaining the contact quality factors including the current period and the previous continuous preset number of periods to form a historical factor sequence; assigning a time decay weight to each contact quality factor in the historical factor sequence; multiplying each contact quality factor in the historical factor sequence with the corresponding time decay weight and summing up, and then dividing the sum by the sum of all weight values to obtain the quotient value, which is the contact state prediction value.

5. The charging method of the Bluetooth earphone charging box according to claim 2, characterized in that, The S23 specifically comprises: calculating the absolute difference value of the contact state prediction value and the current measured impedance value; based on the absolute difference value, determining the trust weight of the prediction value by querying a preset mapping relationship; multiplying the contact state prediction value with the trust weight to obtain a prediction contribution value; at the same time, multiplying the current measured impedance value with a residual value obtained by subtracting the trust weight to obtain a measured contribution value; The prediction contribution value is added to the measured contribution value, and the sum is the filtered impedance value of the current period.

6. The charging method of the Bluetooth earphone charging box according to claim 1, characterized in that, The S3 specifically comprises: In the sliding time window, the proportion of the cumulative duration of the filtered impedance value exceeding the impedance reference range to the total duration of the sliding time window is calculated as the out-of-limit time ratio; In the sliding time window, the difference between the maximum value and the minimum value of the filtered impedance value is calculated as the window range; When the filtered impedance value is within the impedance reference range, the change amount is less than the preset stability threshold, and the window range is less than the first preset range threshold, the stable contact state is recognized; When the out-of-limit time ratio is greater than the preset proportion threshold, the change amount is greater than the preset fluctuation threshold, and the window range is greater than the second preset range threshold, the unstable fluctuation state is recognized; the second preset range threshold is greater than the first preset range threshold.

7. The charging method of the Bluetooth earphone charging box according to claim 1, characterized in that, The inhibition or stop of the charging start instruction triggered based on the instantaneous change of the measured impedance value specifically comprises: Entering the contact protection mode, in which all charging start requests triggered by the drop of the measured impedance value are shielded; In the contact protection mode, the filtered impedance value is continuously detected, and the current contact state is re-identified according to the method of step S3; If the re-identified state is a stable contact state, a stable duration timer is started; if the re-identified state is an unstable fluctuation state, the stable duration timer is reset and an unstable feature counter is incremented; Only when the value of the stable duration timer exceeds the first preset time length and the unstable feature counter is not increased during this period, the contact protection mode is exited and the normal charging state logic judgment is resumed.

8. The charging method of the Bluetooth earphone charging box according to claim 7, characterized in that, The process of entering the contact protection mode comprises: First, when the unstable fluctuation state is first identified, a fluctuation confirmation timer is started; Second, the contact state is continuously re-identified according to the method of step S3 within the timing period of the fluctuation confirmation timer; Third, if the re-identified unstable fluctuation state reaches the preset number threshold within the timing period of the fluctuation confirmation timer, it is determined that the entering condition is met, and the fourth step is executed; Otherwise, the process is exited and the normal state is resumed; Fourth, the charging operation state before entering is saved, and a contact protection mode flag is set to shield all charging start instructions triggered by the instantaneous change of the measured impedance value.

9. A Bluetooth earphone charging case charging system, characterized in that, A Bluetooth earphone charging box charging method for executing any one of claims 1-8, comprising: A parameter acquisition module periodically acquires the measured impedance value of the charging contact and the battery parameter of the earphone when the charging box and the earphone are in a connected state; A dynamic estimation module dynamically estimates the real impedance state of the charging contact by cooperatively analyzing the change trend of the measured impedance value and the corresponding relationship of the battery parameter, and outputs a filtered impedance value; A state recognition module compares the filtered impedance value with a preset impedance reference range according to the change characteristics of the filtered impedance value in continuous time, calculates the change amount of the filtered impedance value in a sliding time window, and recognizes the contact state of the charging contact. The charging control module controls the charging operation of the charging box to the earphone according to the identified contact state; when the stable contact state is identified and the earphone battery is fully charged, the physical disconnection operation of the charging circuit is performed; when the unstable fluctuation state is identified, the charging start instruction triggered based on the instantaneous change of the measured impedance value is inhibited or stopped.

Images