METHOD FOR DIAGNOSTIC THE QUALITY OF WIRELESS COMMUNICATIONS AND BATTERY MANAGEMENT SYSTEM PROVIDING THE SAME

Abstract

The present invention relates to a method for diagnosing the quality of wireless communication and a battery management system that provides the method. A battery management system according to one embodiment of the present invention may include a communication unit that receives a wireless signal including battery information, an RSSI measurement unit that measures the received signal strength (RSSI, Received Signal Strength Indicator) of the wireless signal, a pre-processing unit that calculates an average of the RSSI for each measurement period and calculates a moving average based on the average over a predetermined number of measurement periods with each measurement period as the reference, thereby deriving a compensated RSSI, and a quality diagnosis unit that diagnoses the quality of the wireless communication based on the compensated RSSI.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0180808 dated December 13, 2023 and Korean Patent Application No. 10-2024-0052987 dated April 19, 2024, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0003] The present invention relates to a method for diagnosing the quality of wireless communication and a battery management system that provides the method. [Background technology]

[0004] Battery pack products used in electric vehicles read data using a CVTN ASIC, send the data using a daisy chain method, and transmit cell information to a Battery Management System (BMS) via SPI communication. However, in the case of a wireless BMS, cell data is transmitted to the BMS via RF communication rather than SPI communication. Previously, methods for diagnosing the quality of SPI communication through DTC diagnosis when there was a deterioration in the quality of SPI communication had been disclosed. However, there was no method for diagnosing the quality of BMS wireless communication. Unlike existing wireless communication, in the case of automobiles, which are directly linked to driver safety, reaction through quality diagnosis of wireless communication is important. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method for diagnosing the quality of wireless communication in a battery management system and a battery management system that provides the method. [Means for solving the problem]

[0006] A battery management system according to one embodiment of the present invention may include a communication unit that receives a wireless signal including battery information, an RSSI measurement unit that measures a received signal strength indicator (RSSI) of the wireless signal, a pre-processing unit that calculates an average of the RSSI for each measurement period, calculates a moving average based on an average over a predetermined number of measurement periods based on each measurement period, and derives a compensated RSSI, and a quality diagnosis unit that diagnoses the quality of the wireless communication based on the compensated RSSI.

[0007] The communication unit may transmit the wireless signal to the RSSI measurement unit when the number of unit packets of the battery information is equal to or greater than a reference number.

[0008] When a missing value for the RSSI occurs in a first measurement period during each measurement period, the pre-processing unit can calculate the average RSSI for the first measurement period using the average value of a first average before the first measurement period and a second average after the first measurement period.

[0009] The pre-processing unit can increase a fail count by 1 if no RSSI is received from the RSSI measurement unit in each measurement period, and can decrease the fail count by 1 if RSSI is received from the RSSI measurement unit in each measurement period.

[0010] The quality diagnosis unit can diagnose that a communication error has occurred when the fail count is equal to or greater than a predetermined number.

[0011] When the compensated RSSI exceeds a first reference value, the quality diagnosis unit may diagnose that the quality of the wireless communication is normal.

[0012] The quality diagnosis unit can diagnose that the quality of the wireless communication is in a dangerous state when a pre-risk state in which the compensated RSSI is below a first reference value and exceeds a second reference value smaller than the first reference value is maintained for a predetermined period of time.

[0013] The quality diagnosis unit may diagnose the quality of the wireless communication as being in a defective state if a preliminary defective state in which the compensated RSSI is equal to or less than a second reference value is maintained for a predetermined period of time.

[0014] A wireless communication quality diagnosis method according to one embodiment of the present invention includes a step of: a communication unit receiving a wireless signal including battery information; a step of an RSSI measurement unit measuring the received signal strength (RSSI, Received Signal Strength Indicator) of the wireless signal; a step of a pre-processing unit calculating an average of the RSSI for each measurement period, and for each measurement period, calculating a moving average based on the average over a predetermined number of measurement periods with each measurement period as a reference, thereby deriving a compensated RSSI; and a step of a quality diagnosis unit diagnosing the quality of the wireless communication based on the compensated RSSI.

[0015] The step of receiving the wireless signal may include transmitting the wireless signal to the RSSI measurement unit if the number of unit packets into which the battery information is divided is equal to or greater than a reference number.

[0016] The step of deriving the compensated RSSI may include a step of, when a missing value for the RSSI occurs in a first measurement period during each measurement period, calculating an average RSSI for the first measurement period using an average value of a first average before the first measurement period and a second average after the first measurement period.

[0017] The step of deriving the compensated RSSI may include the steps of: increasing a fail count by 1 if no RSSI is received from the RSSI measurement unit in each measurement period; and decreasing a fail count by 1 if RSSI is received from the RSSI measurement unit in each measurement period.

[0018] The step of diagnosing the quality of the wireless communication may include the step of diagnosing that a communication error has occurred when the fail count is equal to or greater than a predetermined number.

[0019] The step of diagnosing the quality of the wireless communication may include the steps of: diagnosing the quality of the wireless communication to be normal if the compensated RSSI exceeds a first reference value; incrementing a warning count by 1 if the compensated RSSI is equal to or less than the first reference value; diagnosing the quality of the wireless communication to be unsafe if the warning count is equal to or greater than a predetermined number; incrementing a fault count by 1 if the compensated RSSI is equal to or less than a second reference value that is smaller than the first reference value; and diagnosing the quality of the wireless communication to be defective if the fault count is equal to or greater than the predetermined number. [Effects of the Invention]

[0020] According to an embodiment of the present invention, it is possible to accurately diagnose the communication quality between BMSs. In addition, by monitoring the wireless communication quality, it is possible to prevent problems that occur when data is not received due to a communication error at an early stage.

[0021] In addition, when determining wireless communication quality, it eliminates time imbalances for the object of determination, making it possible to diagnose the quality of wireless communication even when temporary communication failures occur, reducing the impact of noise that may be contained in wireless signals, and improving the reliability of data and the accuracy of wireless communication quality determination.

[0022] The effects obtained by the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present disclosure pertains from the description below. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a block diagram of a battery system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of a master BMS according to an embodiment of the present invention. [Figure 3] 1 is a diagram illustrating a preprocessing unit according to an embodiment of the present invention; [Figure 4]1 is a diagram illustrating a preprocessing unit according to an embodiment of the present invention; [Figure 5] 1 is a flowchart of a method for diagnosing wireless communication quality according to an embodiment of the present invention. [Figure 6] 10 is a flowchart of a wireless communication quality diagnosis step according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] In describing the embodiments disclosed herein, if a detailed description of related publicly known technologies is deemed to detract from the gist of the embodiments disclosed herein, the detailed description will be omitted. In addition, the attached drawings are provided to facilitate understanding of the embodiments disclosed herein, and the technical ideas disclosed herein should not be limited by the attached drawings, and should be understood to include all modifications, equivalents, or alternatives within the spirit and technical scope of the present invention.

[0025] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited by these terms. These terms are used only to distinguish one component from another.

[0026] When a component is said to be "coupled" or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that there may be other components in between. On the other hand, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there are no other components in between.

[0027] In this application, the terms "comprise" or "have" and the like are to be understood as specifying the presence of any feature, number, step, operation, component, part, or combination thereof described in the specification, without precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] The present invention will now be described in detail with reference to the accompanying drawings.

[0029] FIG. 1 is a block diagram of a battery system according to an embodiment of the present invention.

[0030] Referring to FIG. 1, a battery system according to an embodiment of the present invention may include a battery 1 and a battery management system (hereinafter referred to as "BMS") 2.

[0031] A battery 1 is connected between two output terminals (OUT1, OUT2) of the battery system. A relay (not shown) may be connected between the positive electrode of the battery system and the first output terminal (OUT1), and a current sensor (not shown) may be connected between the negative electrode of the battery system and the second output terminal (OUT2). In the present disclosure, the potential of the positive electrode is higher than the potential of the negative electrode.

[0032] According to an embodiment, the battery 1 may include a plurality of battery modules connected in series and / or parallel. At this time, each of the plurality of battery modules may include a plurality of battery cells electrically connected in series and parallel. In one embodiment, the battery cells may be rechargeable secondary batteries.

[0033] The relay acts as a kind of switch that controls the electrical connection between the battery system and the external device 3. When the relay is turned on, the battery system and the external device 3 are electrically connected and charging or discharging takes place. When the relay is turned off, the battery system and the external device 3 are electrically separated. In this case, the external device 3 can be a charger in a charging cycle that supplies power to the battery 1 to charge it, and a load in a discharging cycle that the battery 1 discharges power to the external device 3.

[0034] The BMS 2 can include at least one or more slave BMSs (20-1 to 20-N) and a master BMS 10. The multiple slave BMSs (20-1, 20-2 to 20-N) and the master BMS 10 can transmit and receive signals via wireless communication. Hereinafter, the multiple slave BMSs (20-1, 20-2 to 20-N) will be referred to as the slave BMS 20.

[0035] For example, the slave BMS 20 may measure the state of the battery 1 and generate battery information. The battery information refers to information indicating the state of the battery 1. The slave BMS 20 may transmit each of a plurality of sensing signals including the battery information to the master BMS 10 via wireless communication. Furthermore, the master BMS 10 may generate control signals based on the sensing signals and transmit the control signals to the slave BMS 20 via wireless communication. According to an embodiment, the slave BMS 20 may include a communication module.

[0036] According to an embodiment, the battery information may include information measured by the slave BMS 20 (e.g., cell current, cell voltage, cell temperature, etc.) and estimated information (e.g., SOC (State of Charge), SOH (State of Health)).

[0037] FIG. 2 is a block diagram of a master BMS 10 according to one embodiment of the present invention.

[0038] 2, the master BMS 10 according to an embodiment of the present invention may include a communication unit 100 and a control unit 200. According to an embodiment, the communication unit 100 may include an RSSI measurement unit 110, and the control unit 200 may include a pre-processing unit 210, a quality diagnosis unit 220, and a storage unit 230.

[0039] The communication unit 100 may receive a wireless signal including battery information by wirelessly communicating with the slave BMS 20. For example, the communication unit 100 may receive a wireless signal including battery information from the slave BMS 20.

[0040] The communication unit 100 may transmit the received battery information to the external device 3, or may transmit an alarm signal generated by the control unit 200 through analysis of the battery information to the external device 3. According to an embodiment, the external device 3 may be a higher-level system such as an electric vehicle or an energy storage system (ESS).

[0041] In an embodiment, the communication unit 100 can perform wireless communication with the slave BMS 20 and the external device 3 via RF (Radio Frequency), NFC (Near Field Communication), Bluetooth (registered trademark), wifi, ZigBee (registered trademark), etc.

[0042] According to an embodiment, the battery information may be divided into multiple data packets and received from the slave BMS 20. For example, one wireless signal received by the communication unit 100 may include at least one data packet, and a bundle of multiple data packets received by the communication unit 100 may relate to one piece of battery information.

[0043] The communication unit 100 may include an RSSI measurement unit 110 that measures the strength of a received signal (Received Signal Strength Indicator; hereinafter, referred to as "RSSI") of a wireless signal. The RSSI measurement unit 110 may be a signal strength measurement module that measures an RSSI corresponding to the strength of a signal received by the communication unit 100 through wireless communication. The RSSI measurement unit 110 may measure the RSSI of the wireless signal using various known methods. Although FIG. 1 illustrates the RSSI measurement unit 110 as being located within the communication unit 100, the location of the RSSI measurement unit 110 is not limited thereto and may be located anywhere within the master BMS 10.

[0044] The RSSI measurement unit 110 may measure the power present in the received wireless signal to measure the RSSI. The RSSI may be measured in power level units [dBm]. For example, the RSSI may be expressed as a negative value [dBm], and the closer to 0 [dBm], the stronger the signal.

[0045] According to an embodiment, if a predetermined diagnostic condition is satisfied, the communication unit 100 may transmit the received wireless signal to the RSSI measurement unit 110. For example, if the predetermined diagnostic condition is satisfied, the communication unit 100 provides the received wireless signal to the RSSI measurement unit 110. The RSSI measurement unit 110 measures the RSSI of the wireless signal and transmits it to the control unit 200. The control unit 200 diagnoses the wireless communication quality using the RSSI.

[0046] According to an embodiment, the predetermined diagnosis condition may correspond to the number of unit packets into which the battery information is divided being equal to or greater than a reference number. For example, when the number of unit packets into which the received battery information is divided is equal to or greater than a reference number (e.g., 1000), the communication unit 100 may provide a subsequently received wireless signal to the RSSI measurement unit 110. Then, the RSSI measurement unit 110 measures the RSSI and transmits it to the control unit 200. The control unit 200 may diagnose the quality of wireless communication using the RSSI.

[0047] This allows the effectiveness of the wireless communication quality diagnosis to be improved by proceeding with the wireless communication quality diagnosis process after the wireless communication has stabilized, because in wireless communication quality diagnosis, a meaningful diagnosis result can be obtained only when a sufficient number of data packets received through the communication unit 100 have been accumulated.

[0048] The pre-processing unit 210 may generate a compensated RSSI for evaluating the quality of wireless communication based on the RSSI. The pre-processing unit 210 may perform pre-processing, including averaging, missing value correction, and moving average, on the RSSI to derive the compensated RSSI. Here, the compensated RSSI can be used to determine the quality of wireless communication. Meanwhile, the pre-processing process performed by the pre-processing unit 210 on the RSSI is not limited to averaging, missing value correction, and moving average, and other pre-processing processes may be additionally performed in addition to averaging, missing value correction, and moving average.

[0049] Hereinafter, a process in which the pre-processing unit 210 pre-processes the RSSI to derive the compensated RSSI will be described in detail with reference to FIGS.

[0050] The quality diagnosis unit 220 can diagnose the quality of wireless communication based on the compensated RSSI.

[0051] The quality diagnosis unit 220 can determine the quality of wireless communication as a normal state, a warning state, or a fault state. Here, the normal state means a state in which the quality of wireless communication is good. The warning state means an abnormal state in which wireless communication is not good, but can be restored to the normal state by taking a specific measure, such as increasing the power supplied to the communication unit 100. The fault state means an abnormal state in which wireless communication is not good and cannot be restored to the wireless communication state. In this case, an emergency shutdown of a host system (e.g., a vehicle) equipped with the master BMS 10 according to an embodiment of the present invention may be required.

[0052] The quality diagnosis unit 220 can diagnose the quality of wireless communication based on whether the compensated RSSI is equal to or greater than a preset reference value and / or whether it falls within a preset range.

[0053] According to an embodiment, the quality diagnosis unit 220 may diagnose the wireless communication as being in a normal state when the compensated RSSI exceeds a first reference value. The quality diagnosis unit 220 may diagnose the wireless communication as being in a dangerous state when a pre-risk state in which the compensated RSSI is equal to or less than the first reference value and exceeds a second reference value is maintained for a predetermined period of time. The quality diagnosis unit 220 may diagnose the wireless communication as being in a defective state when a pre-defect state in which the compensated RSSI is equal to or less than the second reference value is maintained for a predetermined period of time. In this case, the first and second reference values ​​may be determined based on a power level range that the compensated RSSI can have, and the first reference value may be greater than the second reference value.

[0054] The quality diagnosis unit 220 can count the duration of each pre-risk state and pre-defect state to determine a risk state and a defect state, respectively. The quality diagnosis unit 220 can determine the quality of wireless communication based on whether the counted value of the pre-defect state (hereinafter referred to as the Fault Count) and the counted value of the pre-risk state (hereinafter referred to as the Warning Count) are equal to or greater than a predetermined number. The Fault Count and the Warning Count can be integers equal to or greater than 0.

[0055] That is, when the count of the state where the compensated RSSI exceeds the reference range is equal to or greater than a predetermined number of times, i.e., when the pre-risk state or pre-defect state is maintained for a predetermined period of time, the quality diagnosis unit 220 finally judges the quality of the wireless communication, thereby improving the accuracy of the diagnosis of the quality of the wireless communication. For example, even when the compensated RSSI is equal to or less than the first reference value or exceeds the second reference value, if the warning count is not equal to or greater than a predetermined number (e.g., three), it can be determined that the wireless communication is not in a "risk state."

[0056] According to an embodiment, the quality diagnosis unit 220 may diagnose that the quality of wireless communication is normal when the compensated RSSI exceeds a first reference value. The quality diagnosis unit 220 may increment a warning count by 1 when the compensated RSSI is equal to or less than the first reference value. The quality diagnosis unit 220 may diagnose that the quality of wireless communication is in a dangerous state when the warning count is equal to or greater than a predetermined number. The quality diagnosis unit 220 may increment a fault count by 1 when the compensated RSSI is equal to or less than a second reference value that is smaller than the first reference value. The quality diagnosis unit 220 may diagnose that the quality of wireless communication is in a defective state when the fault count is equal to or greater than a predetermined number. Here, the predetermined numbers for the warning count and the fault count may be preset by a user and stored in the storage unit 230.

[0057] For example, assume that the first reference value is −80 dBm, the second reference value is −85 dBm, the predetermined number (N) is 3, and the warning count and fault count currently recorded in the storage unit 230 are all 2.

[0058] In the above example, if the preprocessing unit 210 determines that the compensated RSSI is −83 dBm, the quality diagnosis unit 220 can increase the warning count to 3 and then diagnose that the wireless communication is in a “dangerous state.”

[0059] Alternatively, in the above example, if the pre-processing unit 210 determines that the compensated RSSI is -90 dBm, the quality diagnosis unit 220 can increase the warning count to 3, increase the fault count to 3, and then diagnose the wireless communication as being in a "faulty state."

[0060] The storage unit 230 may store battery data received through the communication unit 100, a first reference value, a second reference value, a fail count, a warning count, a fault count, etc., which are used as criteria for diagnosing the quality of wireless communication. Here, the fail count can be used to determine whether wireless communication is not being performed. Here, the first reference value and the second reference value are criteria to be compared with the compensated RSSI and may be determined based on a power level range that the compensated RSSI can have, and the first reference value is greater than the second reference value.

[0061] FIG. 3 is a diagram illustrating a pre-processing unit 210 according to an embodiment of the present invention.

[0062] Referring to FIG. 3, the pre-processing unit 210 receives RSSI (S1 to S14) from the RSSI measurement unit 110 at each unit time (hereinafter, measurement period), and can calculate an average value of the RSSI at each measurement period.

[0063] The wireless signals received by the master BMS 10 from the slave BMS 20 may be received at irregular time intervals, which may result in the RSSIs (S1 to S14) received by the preprocessing unit 210 from the RSSI measurement unit 110 being received at irregular time intervals, as shown in (a) of Figure 3.

[0064] In this case, when the quality diagnosis unit 220 diagnoses the quality of wireless communication for each measurement period, there may be a difference in the number of RSSIs received per measurement period, which may cause an imbalance in the assessment target when assessing the quality of wireless communication. For example, two RSSIs (S1, S2) may be received in the "first measurement period," and three RSSIs (S3, S4, S5) may be received in the "second measurement period."

[0065] As a result, the master BMS 10 according to one embodiment of the present invention calculates the average value of the RSSI (S1 to S14) received by the pre-processing unit 210 in each measurement period and uses this to diagnose the quality of wireless communication, thereby eliminating time imbalance for the object of judgment when diagnosing the quality of wireless communication.

[0066] Because the wireless signals received by the communication unit 100 of the master BMS 10 are received irregularly, there are cases where no wireless signals are received during a certain measurement period. As a result, as shown in (a) and (b) of Figure 3, there are cases where no value is provided to the pre-processing unit 210 by the RSSI measurement unit 110 during a measurement period in which no wireless signals are received.

[0067] For example, as in S5 and S6 in FIG. 3A, when wireless communication is not impossible but the wireless communication environment is temporarily unstable, the reception time interval between wireless signals received from the slave BMS 20 may become long. At this time, if the reception time interval between wireless signals is longer than the unit time for which the quality diagnosis unit 220 diagnoses the quality of wireless communication, a case may occur in which no RSSI is received by the pre-processing unit 210, as in the measurement period of "3 periods" in FIG. 3A. In this case, a missing value occurs in the average RSSI value. When a missing value occurs in the average RSSI value, there is no judgment target used by the quality diagnosis unit 220 to judge the quality of wireless communication, and the quality of wireless communication cannot be judged. In other words, a temporary communication failure may cause a case in which wireless communication quality judgment is impossible.

[0068] Therefore, the master BMS 10 according to an embodiment of the present invention can diagnose the quality of wireless communication even when a temporary communication failure occurs by performing missing value correction for missing values ​​through the pre-processing unit 210.

[0069] According to an embodiment, when a missing value exists in the average RSSI value, the preprocessing unit 210 can calculate the average of the average RSSI values ​​calculated before and after the missing value, and replace the missing value. For example, as shown in (b) of FIG. 3, when a missing value (average 3) exists in the average RSSI value, the preprocessing unit 210 can calculate the average of the average RSSI value (average 2) calculated before the missing value (average 3) and the average RSSI value (average 4) calculated after the missing value (average 3) and replace the missing value (average 3).

[0070] As another example, as shown in Figure 3(b), if there are multiple consecutive missing values ​​(averages 5, 6, 7) in the RSSI average value, the average of the RSSI average value (average 4) calculated previously based on the multiple missing values ​​(averages 5, 6, 7) and the RSSI average value (average 8) calculated later based on the multiple missing values ​​(averages 5, 6, 7) can be calculated, and each of the multiple missing values ​​(averages 5, 6, 7) can be replaced.

[0071] Referring to (b) and (c) of FIG. 3, the pre-processing unit 210 can derive a compensated RSSI by applying a moving average filter to the average value of the RSSI.

[0072] Here, a moving average filter is a filter used to analyze data by creating a series of averages for multiple subsets of an entire data set, and corresponds to a type of impulse response filter.

[0073] That is, the pre-processing unit 210 can apply a moving average filter to the average RSSI values ​​and calculate a series of averages for some of the average RSSI values ​​continuously received every unit time.

[0074] For example, in order to derive the compensated RSSI (S'6) for the measurement period "6 periods" in Figure 2, the pre-processing unit 210 can calculate the average of the average RSSI values ​​for multiple measurement periods "2 periods to 6 periods" from the "6 periods" to the measurement periods "2 periods" to "6 periods" that are n periods (e.g., four periods) before the "6 periods."

[0075] A wireless signal received through wireless communication may contain noise generated by internal or external obstacles. When the pre-processing unit 210 calculates an average RSSI value for a wireless signal containing noise, the average RSSI value may be relatively larger or smaller than other average values. That is, the average RSSI value may also contain noise. If the quality of wireless communication is determined after deriving a compensated RSSI without correcting the noise contained in the average RSSI value, the accuracy of determining the quality of wireless communication may be reduced.

[0076] As a result, as shown in (c) of FIG. 3, the master BMS 10 according to one embodiment of the present invention can improve the reliability of data and the accuracy of wireless communication quality judgment by applying a moving average filter through the pre-processing unit 210 to reduce the influence of noise that may be contained in the wireless signal.

[0077] FIG. 4 is a diagram illustrating a pre-processing unit 210 according to an embodiment of the present invention.

[0078] Referring to FIG. 4, the pre-processing unit 210 can increase or decrease a fail count based on whether or not the RSSI received from the RSSI measuring unit 110 exists every unit time.

[0079] Here, the fail count corresponds to the number of times that RSSI is not received from the RSSI measurement unit 110 within a unit time, and is an integer equal to or greater than 0. The fail count is used to determine a state in which a communication error occurs, in which wireless communication is not performed, i.e., a state in which wireless communication is impossible. According to an embodiment, the fail count may be recorded in the storage unit 230.

[0080] According to the embodiment, the pre-processing unit 210 can increase the fail count by 1 if there is no RSSI received from the RSSI measurement unit 110 during the measurement period, and can decrease the fail count by 1 if there is RSSI received from the RSSI measurement unit 110 during the measurement period.

[0081] 4, the pre-processing unit 210 can increase the fail count by 1 (FC=1) for "3 cycles" when RSSI is not present, and decrease the fail count by 1 (FC=0) for "4 cycles" when RSSI is present. Furthermore, if RSSI is not present for N-3 to N consecutive cycles, the pre-processing unit 210 can increase the fail count by 1 (FC=1 to 4) for each measurement cycle.

[0082] According to an embodiment, the quality diagnosis unit 220 can determine whether a communication error has occurred based on whether the fail count is greater than or equal to a predetermined number before diagnosing the quality of wireless communication based on the compensated RSSI derived through the pre-processing unit 210.

[0083] 3, for example, the quality diagnosis section 220 can determine whether the fail count is 4 or more at regular intervals. Also, the quality diagnosis section 220 can determine that a communication error has occurred in N periods in which the fail count is 4 or more.

[0084] FIG. 5 is a flowchart of a method for diagnosing wireless communication quality according to an embodiment of the present invention.

[0085] Referring to FIG. 5, a wireless communication quality diagnosis method according to one embodiment of the present invention may include a wireless signal receiving step (S100), an RSSI measurement step (S200), an RSSI preprocessing step (S300), and a wireless communication quality diagnosis step (S400).

[0086] In the wireless signal receiving step (S100), the communication unit 100 can receive a wireless signal including battery information by wirelessly communicating with the slave BMS 20. For example, the communication unit 100 can receive a wireless signal including battery information from the slave BMS 20.

[0087] According to the embodiment, in the wireless signal receiving step (S100), if the communication unit 100 satisfies a predetermined diagnostic condition, the communication unit 100 may transmit the received wireless signal to the RSSI measurement unit 110. For example, if the predetermined diagnostic condition is satisfied, the communication unit 100 provides the received wireless signal to the RSSI measurement unit 110.

[0088] According to an embodiment, the predetermined diagnostic condition may correspond to the number of unit packets into which the battery information is divided being equal to or greater than a reference number. For example, when the number of unit packets into which the received battery information is divided is equal to or greater than a reference number (e.g., 1000), the communication unit 100 may provide the subsequently received wireless signal to the RSSI measurement unit 110.

[0089] In the RSSI measurement step (S200), the RSSI measurement unit 110 may measure the RSSI of the wireless signal. At this time, the RSSI measured by the RSSI measurement unit 110 may be transmitted to the control unit 200.

[0090] Here, the received signal strength indicator (RSSI) is a value that measures the power present in the received wireless signal, and the measurement unit for RSSI can be expressed in power level units [dBm]. For example, RSSI can be expressed as a "negative value [dBm]", and the closer to "0 [dBm]", the stronger the signal.

[0091] In the RSSI preprocessing step (S300), the preprocessing unit 210 performs preprocessing on the RSSI, including averaging, missing value correction, and moving average, to derive a compensated RSSI, which can be used to determine the quality of wireless communication.

[0092] For example, in the RSSI preprocessing step (S300), the preprocessing unit 210 may receive RSSI from the RSSI measurement unit 110 every unit time and calculate an average RSSI value every unit time (S310). If a missing value is present in the calculated average RSSI value, the preprocessing unit 210 may calculate an average of the average RSSI values ​​calculated before and after the missing value and replace the missing value (S320). In addition, the preprocessing unit 210 may apply a moving average filter to the average RSSI value to derive a compensated RSSI (S330).

[0093] As a result, the master BMS 10 according to one embodiment of the present invention can eliminate time imbalances for the objects of judgment when judging the quality of wireless communication, and can diagnose the quality of wireless communication even when a temporary communication failure occurs. It can also reduce the influence of noise that may be contained in the wireless signal, thereby improving the reliability of data and the accuracy of the judgment of the quality of wireless communication.

[0094] According to an embodiment, the RSSI pre-processing step (S300) may include a step of increasing or decreasing a fail count based on whether or not RSSI is received per unit time from the RSSI measurement unit 110. For example, in the RSSI pre-processing step (S300), the pre-processing unit 210 may include a step of incrementing the fail count by 1 if no RSSI is received per unit time from the RSSI measurement unit 110, and a step of decrementing the fail count by 1 if a compensation RSSI generated by the RSSI measurement unit 110 is present per unit time. In this case, in the wireless communication quality diagnosis step (S400), the quality diagnosis unit 220 may include a step of diagnosing that a communication error has occurred if the fail count is equal to or greater than a predetermined number (S410).

[0095] In the wireless communication quality diagnosis step (S400), the quality diagnosis unit 220 can diagnose the quality of wireless communication based on the compensated RSSI. Hereinafter, the wireless communication quality diagnosis step (S400) according to an embodiment of the present invention will be described in detail with reference to FIG. 6.

[0096] Referring to FIG. 6, in the wireless communication quality diagnosis step (S400) according to one embodiment of the present invention, the quality diagnosis unit 220 can diagnose the quality of wireless communication based on whether the compensation RSSI is greater than or equal to a preset reference value and / or whether it falls within a preset range.

[0097] According to an embodiment, the wireless communication quality diagnosis step (S400) may include the steps of: diagnosing the wireless communication as being in a normal state when the compensated RSSI exceeds a first reference value; diagnosing the wireless communication as being in a dangerous state when a pre-risk state in which the compensated RSSI is equal to or less than the first reference value and exceeds a second reference value is maintained for a predetermined period; and diagnosing the wireless communication as being in a defective state when a pre-defect state in which the compensated RSSI is equal to or less than the second reference value is maintained for a predetermined period. In this case, the first reference value and the second reference value may be determined based on a power level range that the compensated RSSI can have, and the first reference value is greater than the second reference value.

[0098] According to an embodiment, the wireless communication quality diagnosis step (S400) may include a step of counting the period maintained in each of the pre-risk state and the pre-fault state so that the quality diagnosis unit 220 determines the pre-risk state and the fault state, respectively.

[0099] According to an embodiment, the wireless communication quality diagnosis step (S400) may include a step of determining the quality of wireless communication based on whether or not the value counted by the quality diagnosis unit 220 for a preliminary fault state (hereinafter referred to as a fault count) and the value counted by the quality diagnosis unit 220 for a preliminary danger state (hereinafter referred to as a warning count) are equal to or greater than a predetermined number. Here, the fault count and the warning count may be integers equal to or greater than 0.

[0100] That is, in the wireless communication quality diagnosis step (S400), if the count result of the state where the compensated RSSI exceeds the reference range is equal to or greater than a predetermined number of times, i.e., if the pre-risk state or pre-defect state is maintained for a predetermined period of time, the quality diagnosis unit 220 finally makes a judgment on the quality of wireless communication, thereby improving the accuracy of the diagnosis on the quality of wireless communication. For example, even if the compensated RSSI is equal to or less than a first reference value and exceeds a second reference value, if the warning count is not equal to or greater than a predetermined number (e.g., 3), it can be determined that the wireless communication is not in a "risk state."

[0101] According to an embodiment, the method may include a step of diagnosing wireless communication quality (S400), a step of the quality diagnosis unit 220 receiving a compensation RSSI from the pre-processing unit 210 (S420), a step of diagnosing that the quality of wireless communication is normal if the compensation RSSI exceeds a first reference value (S431) (S432), a step of incrementing a warning count by 1 if the compensation RSSI is equal to or less than the first reference value (S441), a step of diagnosing that the quality of wireless communication is unsafe if the warning count is equal to or greater than a predetermined number (S442) (S443), a step of incrementing a fault count by 1 if the compensation RSSI is equal to or less than a second reference value that is smaller than the first reference value (S451), and a step of diagnosing that the quality of wireless communication is defective if the fault count is equal to or greater than a predetermined number (S453). Here, the predetermined numbers for the warning count and the fault count may be preset by a user and stored in the storage unit 230.

[0102] For example, it is assumed that the first reference value is −80 dBm, the second reference value is −85 dBm, the predetermined number (N) is 3, and the warning count and fault count currently recorded in the storage unit 230 are both 2.

[0103] In the above example, if the preprocessing unit 210 determines that the compensated RSSI is −83 dBm, the quality diagnosis unit 220 can increase the warning count to 3 and then diagnose that the wireless communication is in a “dangerous state.”

[0104] Alternatively, in the above example, if the pre-processing unit 210 determines that the compensated RSSI is -90 dBm, the quality diagnosis unit 220 can increase the warning count to 3, increase the fault count to 3, and then diagnose the wireless communication as being in a "faulty state."

[0105] Meanwhile, the above-described method can be created as a computer-executable program and can be implemented on a general-purpose digital computer that runs the program using a computer-readable recording medium, which can include storage media such as ROM, RAM, USB, magnetic storage media such as a floppy disk, or hard disk, or optically readable media such as a CD-ROM or DVD.

[0106] The scope of the present invention is indicated by the claims that follow rather than by the above detailed description, and all modifications and variations that fall within the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims

1. a communication unit that receives a wireless signal containing battery information; an RSSI measurement unit that measures a received signal strength (RSSI) of the wireless signal; a pre-processing unit that calculates an average of the RSSI for each measurement period, calculates a moving average for each measurement period based on an average over a predetermined number of measurement periods with each measurement period as a reference, and derives a compensated RSSI; and a quality diagnosis unit that diagnoses the quality of wireless communication based on the compensated RSSI; Battery management system.

2. The communication unit If the number of unit packets into which the battery information is divided is equal to or greater than a reference number, the wireless signal is transmitted to the RSSI measurement unit. The battery management system of claim 1 .

3. The pre-treatment unit If a missing value for the RSSI occurs in a first measurement period during each measurement period, calculating an average RSSI for the first measurement period using an average value of a first average before the first measurement period and a second average after the first measurement period; The battery management system of claim 1 .

4. The pre-treatment unit If there is no RSSI received from the RSSI measurement unit in each measurement period, the fail count is increased by 1, and if there is RSSI received from the RSSI measurement unit in each measurement period, the fail count is decreased by 1. The battery management system of claim 1 .

5. The quality diagnosis unit If the fail count is equal to or greater than a predetermined number, a communication error is diagnosed. The battery management system of claim 4 .

6. The quality diagnosis unit If the compensated RSSI exceeds a first reference value, the quality of the wireless communication is diagnosed as normal. The battery management system according to any one of claims 1 to 5.

7. The quality diagnosis unit If the compensated RSSI is equal to or less than a first reference value and exceeds a second reference value that is smaller than the first reference value, a pre-risk state is maintained for a predetermined period of time, diagnosing the quality of the wireless communication as being in a risk state. The battery management system according to any one of claims 1 to 5.

8. The quality diagnosis unit If the pre-defect state in which the compensated RSSI is equal to or less than a second reference value is maintained for a predetermined period of time, the quality of the wireless communication is diagnosed as being in a defective state. The battery management system according to any one of claims 1 to 5.

9. a communication unit receiving a wireless signal including battery information; a step in which an RSSI measurement unit measures the received signal strength (RSSI) of the wireless signal; a pre-processing unit calculating an average of the RSSI for each measurement period, and calculating a moving average for each measurement period based on an average over a predetermined number of measurement periods with respect to each measurement period, thereby deriving a compensated RSSI; and a quality diagnosis unit diagnosing quality of wireless communication based on the compensated RSSI; A method for diagnosing wireless communication quality.

10. The step of receiving a wireless signal includes: transmitting the wireless signal to the RSSI measuring unit when the number of unit packets into which the battery information is divided is equal to or greater than a reference number; The method for diagnosing wireless communication quality according to claim 9 .

11. The step of deriving the compensated RSSI includes: and if a missing value for the RSSI occurs in a first measurement period during each of the measurement periods, calculating an average of the RSSI for the first measurement period using an average of a first average before the first measurement period and a second average after the first measurement period. The method for diagnosing wireless communication quality according to claim 9 .

12. The step of deriving the compensated RSSI includes: Incrementing a fail count by 1 if no RSSI is received from the RSSI measurement unit in each measurement period; and a step of decreasing a fail count by 1 when an RSSI is received from the RSSI measurement unit in each measurement period; The method for diagnosing wireless communication quality according to claim 9 .

13. The step of diagnosing quality of wireless communication includes: a step of diagnosing that a communication error has occurred when the fail count is equal to or greater than a predetermined number; The method for diagnosing wireless communication quality according to claim 12.

14. The step of diagnosing quality of wireless communication includes: diagnosing that the quality of the wireless communication is normal when the compensated RSSI exceeds a first reference value; increasing a warning count by 1 when the compensated RSSI is equal to or less than the first reference value; a step of diagnosing that the quality of the wireless communication is in a dangerous state when the warning count is equal to or greater than a predetermined number; incrementing a fault count by one if the compensated RSSI is less than or equal to a second reference value that is less than the first reference value; and If the fault count is equal to or greater than a predetermined number, diagnosing the quality of the wireless communication as being defective. The method for diagnosing wireless communication quality according to any one of claims 9 to 13.

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