Method for diagnosing quality of wireless communication, and battery management system for providing method

Abstract

The present invention relates to a method for diagnosing the quality of wireless communication, and a battery management system for providing the method. The battery management system according to one embodiment of the present invention may comprise: a communication unit for receiving a wireless signal including battery information; a received signal strength indicator (RSSI) measurement unit for measuring an RSSI of the wireless signal; a preprocessing unit which calculates the average of the RSSI for each measurement period, and which calculates the movement average on the basis of averages during a predetermined number of measurement periods with respect to each measurement period for every measurement period so as to derive a compensated RSSI; and a quality diagnosis unit for diagnosing the quality of the wireless communication on the basis of the compensated RSSI.

Description

A method for diagnosing the quality of wireless communication and a battery management system providing the method

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0180808, filed December 13, 2023, and Korean Patent Application No. 10-2024-0052987, filed April 19, 2024, the entire contents of which 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 providing the method.

[0004] Battery pack products used in electric vehicles read data using a CVTN ASIC, transmit data in a daisy-chain fashion, and transmit cell information to the Battery Management System (BMS) via SPI communication. However, wireless BMSs transmit cell data to the BMS via RF communication, not SPI. Conventionally, methods for diagnosing SPI communication quality through DTC diagnosis have been disclosed when quality deterioration occurs. However, no method exists for diagnosing the quality of BMS wireless communication. Unlike existing wireless communication, in automobiles, where driver safety is directly linked, a response through wireless communication quality diagnosis is crucial.

[0005] The present invention aims to provide a method for diagnosing the quality of wireless communication of a battery management system and a battery management system providing the method.

[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 the received signal strength (RSSI, Received Signal Strength Indicator) of the wireless signal, a preprocessing unit that calculates an average for the RSSI for each measurement period and calculates a moving average based on averages for a predetermined number of measurement periods based on each measurement period to derive a compensation RSSI, and a quality diagnosis unit that diagnoses the quality of the wireless communication based on the compensation RSSI.

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

[0008] The above preprocessing unit can calculate an average for the RSSI of the first measurement period as an average value of a first average before the first measurement period and a second average after the first measurement period, when a missing value for the RSSI occurs in the first measurement period among the above measurement periods.

[0009] The above preprocessing unit can increase the fail count by 1 when there is no RSSI received from the RSSI measurement unit for each measurement cycle, and can decrease the fail count by 1 when there is RSSI received from the RSSI measurement unit for each measurement cycle.

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

[0011] The above quality diagnosis unit can diagnose that the quality of the wireless communication is normal when the compensation RSSI exceeds the first reference value.

[0012] The above quality diagnosis unit can diagnose that the quality of the wireless communication is in a dangerous state when a preliminary dangerous state in which the compensation RSSI is lower than a first reference value and higher than a second reference value that is lower than the first reference value is maintained for a predetermined period of time.

[0013] The above quality diagnosis unit can diagnose that the quality of the wireless communication is defective when the preliminary defective state in which the compensation RSSI is lower than the 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 may include a step in which a communication unit receives a wireless signal including battery information, a step in which an RSSI measurement unit measures a received signal strength (RSSI, Received Signal Strength Indicator) of the wireless signal, a step in which a preprocessing unit calculates an average of the RSSI for each measurement period, and a step in which a moving average based on an average for a predetermined number of measurement periods based on each measurement period is calculated for each measurement period to derive a compensation RSSI, and a step in which a quality diagnosis unit diagnoses the quality of the wireless communication based on the compensation RSSI.

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

[0016] The step of deriving the above compensation RSSI may include a step of calculating an average for the RSSI of the first measurement period as an average value of a first average before the first measurement period and a second average after the first measurement period, when a missing value for the RSSI occurs in the first measurement period among the above measurement periods.

[0017] The step of deriving the above compensation RSSI may include a step of increasing the fail count by 1 when there is no RSSI received from the RSSI measurement unit for each measurement period; and a step of decreasing the fail count by 1 when there is RSSI received from the RSSI measurement unit for each measurement period.

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

[0019] The step of diagnosing the quality of the wireless communication may include a step of diagnosing the quality of the wireless communication as being normal when the compensation RSSI exceeds a first reference value, a step of increasing a warning count by 1 when the compensation RSSI is less than or equal to the first reference value, a step of diagnosing the quality of the wireless communication as being in a dangerous state when the warning count is greater than or equal to a predetermined number, a step of increasing a fault count by 1 when the compensation RSSI is less than or equal to a second reference value that is less than the first reference value, and a step of diagnosing the quality of the wireless communication as being in a defective state when the fault count is greater than or equal to a predetermined number.

[0020] According to one embodiment of the present invention, communication quality between BMSs can be accurately diagnosed. Furthermore, by monitoring wireless communication quality, problems arising from data failure due to communication errors can be prevented early.

[0021] In addition, it can resolve time imbalance in the judgment target when judging wireless communication quality, enable diagnosis of wireless communication quality even when temporary communication failure occurs, and reduce the influence of noise that may be included in wireless signals, thereby improving data reliability and accuracy of wireless communication quality judgment.

[0022] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0023] FIG. 1 is a block diagram of a battery system according to one embodiment of the present invention.

[0024] FIG. 2 is a block diagram of a master BMS according to one embodiment of the present invention.

[0025] FIG. 3 and FIG. 4 are drawings for explaining a preprocessing unit according to one embodiment of the present invention.

[0026] Figure 5 is a flowchart of a wireless communication quality diagnosis method according to one embodiment of the present invention.

[0027] Figure 6 is a flowchart of a wireless communication quality diagnosis step according to one embodiment of the present invention.

[0028] In describing the embodiments disclosed in this specification, detailed descriptions of related known technologies will be omitted if it is determined that such detailed descriptions may obscure the gist of the embodiments disclosed in this specification. In addition, the attached drawings are provided solely to facilitate understanding of the embodiments disclosed in this specification, and the technical concepts disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included within the spirit and technical scope of the present invention.

[0029] Terms that include 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 solely to distinguish one component from another.

[0030] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0031] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0032] The present invention will be described in detail with reference to the attached drawings below.

[0033] FIG. 1 is a block diagram of a battery system according to one embodiment of the present invention.

[0034] Referring to FIG. 1, a battery system according to one embodiment of the present invention may include a battery (1), a relay (2), and a battery management system (hereinafter referred to as 'BMS') (3).

[0035] A battery (1) is connected between two output terminals (OUT1, OUT2) of the battery system. A relay (2) 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.

[0036] In some embodiments, the battery (1) may include a plurality of battery modules connected in series and / or parallel. 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.

[0037] The relay (2) acts as a kind of switch that controls the electrical connection between the battery system and the external device (4). When the relay is turned on, the battery system and the external device (4) are electrically connected and charging or discharging is performed. When the relay is turned off, the battery system and the external device (4) are electrically separated. At this time, the external device (4) may be a charger in a charging cycle in which power is supplied to the battery (1) to charge it, and a load in a discharging cycle in which the battery (1) discharges power to the external device (4).

[0038] The BMS (3) may include at least one slave BMS (20-1 to N) and a master BMS (10). The plurality of slave BMSs (20-1, 20-2 to 20-N) and the master BMS (10) may transmit and receive signals using a wireless communication method. Hereinafter, the plurality of slave BMSs (20-1, 20-2 to 20-N) are collectively referred to as the slave BMS (20).

[0039] For example, the slave BMS (20) can measure the status of the battery (1) to generate battery information. The battery information refers to information indicating the status of the battery (1). The slave BMS (20) can wirelessly transmit each of a plurality of sensing signals including battery information to the master BMS (10). In addition, the master BMS (10) can generate a control signal based on the sensing signal and wirelessly transmit each of the control signals to the slave BMS (20). According to an embodiment, the slave BMS (20) can include a communication module.

[0040] Depending on the 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., State of Charge (SOC), State of Health (SOH)).

[0041] Figure 2 is a block diagram of a master BMS (10) according to one embodiment of the present invention.

[0042] Referring to FIG. 2, a master BMS (10) according to one embodiment of the present invention may include a communication unit (100) and a control unit (200). Depending on the embodiment, the communication unit (100) may include an RSSI measurement unit (110), and the control unit (200) may include a preprocessing unit (210), a quality diagnosis unit (220), and a storage unit (230).

[0043] The communication unit (100) can perform wireless communication with the slave BMS (20) to receive a wireless signal containing battery information. For example, the communication unit (100) can receive a wireless signal containing battery information from the slave BMS (20).

[0044] The communication unit (100) may transmit battery information received by an external device (4) or transmit an alarm signal generated by the control unit (200) through analysis of battery information to the external device (4). Depending on the embodiment, the external device (4) may be an upper system such as an electric vehicle or an energy storage system (ESS).

[0045] According to an embodiment, the communication unit (100) can perform wireless communication with the slave BMS (20) and the external device (4) through RF (Radio Frequency), NFC (Near Field Communication), Bluetooth, Wi-Fi, ZigBee, etc.

[0046] Depending on the embodiment, 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 be for one battery information.

[0047] The communication unit (100) may include an RSSI measurement unit (110) that measures the received signal strength (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 the RSSI corresponding to the signal strength received by the communication unit (100) through wireless communication. The RSSI measurement unit (110) may measure the RSSI of a wireless signal by various methods known in the art. Although the RSSI measurement unit (110) is illustrated as being located within the communication unit (100) in FIG. 1, the location of the RSSI measurement unit (110) is not limited thereto, and may be located anywhere within the master BMS (10).

[0048] The RSSI measurement unit (110) can measure RSSI by measuring the power present in the received wireless signal. The RSSI measurement unit can be expressed as a power level unit [dBm]. For example, RSSI can be expressed as a 'negative value [dBm]', and the closer it is to '0 [dBm]', the stronger the signal.

[0049] According to an embodiment, the communication unit (100) may transmit the received wireless signal to the RSSI measurement unit (110) when a predetermined diagnostic condition is satisfied. For example, the communication unit (100) provides the received wireless signal to the RSSI measurement unit (110) when a predetermined diagnostic condition is satisfied. The RSSI measurement unit (110) measures the RSSI for the wireless signal and transmits it to the control unit (200). The control unit (200) uses the RSSI to diagnose the wireless communication quality.

[0050] According to an embodiment, a predetermined diagnostic condition may correspond to a number of battery information divided into unit packets being greater than or equal to a reference number. For example, if the number of battery information divided into unit packets received is greater than or equal to a reference number (e.g., 1000), the communication unit (100) may provide wireless signals received thereafter 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 use the RSSI to diagnose the quality of wireless communication.

[0051] Accordingly, by conducting a wireless communication quality diagnosis process after the wireless communication has stabilized, the effectiveness of wireless communication quality diagnosis can be improved. This is because, in order to obtain meaningful diagnostic results in wireless communication quality diagnosis, a sufficient number of data packets received through the communication unit (100) must be accumulated.

[0052] The preprocessing unit (210) can generate a compensation RSSI for evaluating the quality of wireless communication based on the RSSI. The preprocessing unit (210) can perform preprocessing including averaging, missing value correction, and moving average on the RSSI to derive the compensation RSSI. Here, the compensation RSSI can be used to determine the quality of wireless communication. Meanwhile, the preprocessing process performed by the preprocessing unit (210) on the RSSI is not limited to averaging, missing value correction, and moving average, and other preprocessing processes may be additionally performed in addition to averaging, missing value correction, and moving average.

[0053] Hereinafter, with reference to FIGS. 3 and 4, the process of the preprocessing unit (210) preprocessing RSSI to derive compensation RSSI will be described in detail.

[0054] The quality diagnosis unit (220) can diagnose the quality of wireless communication based on the compensation RSSI.

[0055] 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 the wireless communication is not good, but can be restored to the normal state if a specific measure, such as increasing the power supplied to the communication unit (100), is taken. The fault state means an abnormal state in which the wireless communication is not good, and the state of the wireless communication cannot be restored. In this case, an emergency shutdown of an upper system (e.g., a vehicle, etc.) equipped with a master BMS (10) according to an embodiment of the present invention may be required.

[0056] The quality diagnosis unit (220) can diagnose the quality of wireless communication based on whether the compensation RSSI is higher than a preset reference value and / or falls within a preset range.

[0057] According to an embodiment, the quality diagnosis unit (220) may diagnose that the wireless communication is in a normal state if the compensation RSSI exceeds a first reference value. The quality diagnosis unit (220) may diagnose that the wireless communication is in a dangerous state if a pre-danger state in which the compensation RSSI is lower than the first reference value and higher than the second reference value is maintained for a predetermined period of time. The quality diagnosis unit (220) may diagnose that the wireless communication is in a defective state if a pre-defect state in which the compensation RSSI is lower than the second reference value is maintained for a predetermined period of time. At this time, the first reference value and the second reference value may be determined based on a power level range that the compensation RSSI may have, and the first reference value is greater than the second reference value.

[0058] The quality diagnosis unit (220) can count the period of time maintained in the pre-danger state and the pre-defect state, respectively, in order to determine the risk state and the 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, “Fault Count”) and the counted value of the pre-danger state (hereinafter, “Warning Count”) are equal to or greater than a predetermined number. The Fault Count and the Warning Count may be integers greater than or equal to 0.

[0059] That is, the quality diagnosis unit (220) can improve the accuracy of the diagnosis of the quality of wireless communication by finally performing a judgment on the quality of wireless communication when the result of counting the state in which the compensation RSSI is out of the reference range is more than a predetermined number of times, that is, when the preliminary risk state or preliminary defect state is maintained for a predetermined period of time. For example, even when the compensation RSSI is less than the first reference value and more than the second reference value, if the warning count is not more than a predetermined number (e.g., 3), the wireless communication can be determined not to be in a 'dangerous state'.

[0060] According to an embodiment, the quality diagnosis unit (220) may diagnose that the quality of the wireless communication is normal when the compensation RSSI exceeds the first reference value. The quality diagnosis unit (220) may increase the warning count by 1 when the compensation RSSI is lower than or equal to the first reference value. The quality diagnosis unit (220) may diagnose 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. The quality diagnosis unit (220) may increase the fault count by 1 when the compensation RSSI is lower than or equal to a second reference value that is smaller than the first reference value. The quality diagnosis unit (220) may diagnose that the quality of the 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 the user and stored in the storage unit (230).

[0061] 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 both 2.

[0062] In the above example, if the preprocessing unit (210) determines that the compensation 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'.

[0063] Alternatively, in the above example, if the preprocessing unit (210) determines that the compensation RSSI is -90 dBm, the quality diagnosis unit (220) may increase the warning count to 3, increase the fault count to 3, and then diagnose that the wireless communication is in a 'defective state'.

[0064] The storage unit (230) can store battery data received through the communication unit (100), a first reference value, a second reference value, a fail count, a warning count, and a fault count 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 can be determined based on a power level range that the compensation RSSI can have as criteria for comparison with the compensation RSSI, and the first reference value is greater than the second reference value.

[0065] FIG. 3 is a drawing for explaining a preprocessing unit (210) according to one embodiment of the present invention.

[0066] Referring to FIG. 3, the preprocessing unit (210) receives RSSI (S1 to S14) from the RSSI measurement unit (110) for each unit time (hereinafter, measurement cycle) and can calculate the average value of RSSI for each measurement cycle.

[0067] Wireless signals received from the slave BMS (20) to the master BMS (10) may be received at irregular time intervals. Accordingly, as illustrated in Fig. 3(a), RSSIs (S1 to S14) received from the RSSI measurement unit (110) to the preprocessing unit (210) may also be received at irregular time intervals.

[0068] At this time, when the quality diagnosis unit (220) diagnoses the quality of wireless communication for each measurement cycle, there may be a difference in the number of RSSIs received for each measurement cycle, and thus an imbalance may occur in the judgment target when judging the quality of wireless communication. For example, two RSSIs (S1, S2) may be received for the “1st cycle” of the measurement cycle, and three RSSIs (S3, S4, S5) may be received for the “2nd cycle” of the measurement cycle.

[0069] Accordingly, the master BMS (10) according to one embodiment of the present invention calculates the average value of RSSI (S1 to S14) received by the preprocessing unit (210) for each measurement cycle and uses this to diagnose the quality of wireless communication, thereby eliminating time imbalance for the judgment target when diagnosing the quality of wireless communication.

[0070] As wireless signals received by the communication unit (110) of the master BMS (10) are received irregularly, wireless signals may not be received during certain measurement periods. Accordingly, as illustrated in FIGS. 3(a) and (b), during measurement periods in which wireless signals are not received, there may be no value provided by the RSSI measurement unit (110) to the preprocessing unit (210).

[0071] For example, although wireless communication is not impossible as in S5 and S6 of Fig. 3(a), if 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 diagnosing the quality of wireless communication in the quality diagnosis unit (220), there may be a case where no RSSI is received by the preprocessing unit (210), as in the measurement cycle “3 cycles” of Fig. 3(a). In this case, a missing value occurs in the average value of the RSSIs. If a missing value occurs in the average value of the RSSIs, the quality diagnosis unit (220) does not have a judgment target used to determine the quality of wireless communication, so the quality of wireless communication cannot be determined. In other words, there may be a case where wireless communication quality determination is impossible due to a temporary communication failure.

[0072] Accordingly, the master BMS (10) according to one embodiment of the present invention performs missing value correction for missing values ​​through the preprocessing unit (210), thereby enabling quality diagnosis of wireless communication even when a temporary communication failure occurs.

[0073] According to an embodiment, when there is a missing value in the average value of RSSI, the preprocessing unit (210) may replace the missing value by calculating the average of the average values ​​of RSSI calculated before and after the missing value. For example, as illustrated in FIG. 3(b), when there is a missing value (average 3) in the average value of RSSI, the missing value (average 3) may be replaced by calculating the average of the average value of RSSI (average 2) calculated before the missing value (average 3) and the average value of RSSI (average 4) calculated after the missing value (average 3).

[0074] In addition, as another example, as shown in Fig. 3(b), when there are multiple missing values ​​(average 5, 6, 7) consecutively in the average value of RSSI, the average value of RSSI (average 4) calculated before based on the multiple missing values ​​(average 5, 6, 7) and the average value of RSSI (average 8) calculated later based on the multiple missing values ​​(average 5, 6, 7) can be calculated to replace each of the multiple missing values ​​(average 5, 6, 7).

[0075] Referring to FIGS. 3(b) and (c), the preprocessing unit (210) can derive a compensation RSSI by applying a moving average filter to the average values ​​of RSSI.

[0076] Here, the moving average filter is a type of impulse response filter used to analyze data by creating a series of averages for multiple subsets of the entire data set.

[0077] That is, the preprocessing unit (210) can apply a moving average filter to the average values ​​of RSSI, thereby calculating a series of averages for some of the average values ​​of RSSI that are continuously received at each unit time.

[0078] For example, in order to derive the compensation RSSI (S'6) for the measurement cycle "6 cycles" of FIG. 2, the preprocessing unit (210) can calculate the average of the RSSI average values ​​for a plurality of measurement cycles "2 cycles to 6 cycles" from "2 cycles" to "6 cycles" that are n (e.g., 4) previous measurement cycles from "6 cycles".

[0079] Wireless signals received via wireless communication may contain noise generated by internal or external obstacles. When calculating the RSSI average value through the preprocessing unit (210) for a wireless signal containing noise, the RSSI average value may be relatively larger or smaller than other average values. In other words, the RSSI average value may also contain noise. If the noise contained in the RSSI average value is not corrected and the compensated RSSI is derived and then the quality of the wireless communication is determined, the accuracy of the wireless communication quality determination may decrease.

[0080] Accordingly, as illustrated in FIG. 3(c), 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 reducing the influence of noise that may be included in a wireless signal by applying a moving average filter through the preprocessing unit (210).

[0081] Figure 4 is a drawing for explaining a preprocessing unit (210) according to one embodiment of the present invention.

[0082] Referring to FIG. 4, the preprocessing unit (210) can increase or decrease the fail count based on the presence or absence of RSSI received from the RSSI measurement unit (110) for each unit time.

[0083] Here, the fail count corresponds to the number of times RSSI is not received from the RSSI measurement unit (110) during a unit of time, and is an integer greater than or equal to 0. The fail count is used to determine a state in which a communication error has occurred, i.e., a state in which wireless communication is not possible. In some embodiments, the fail count may be recorded in the storage unit (230).

[0084] According to an embodiment, the preprocessing unit (210) may increase the fail count by 1 when there is no RSSI received from the RSSI measurement unit (110) during the measurement period, and may decrease the fail count by 1 when there is RSSI received from the RSSI measurement unit (110) during the measurement period.

[0085] For example, as illustrated in FIG. 4, the preprocessing unit (210) can increase the fail count by 1 (FC=1) in “cycle 3” where RSSI does not exist, and decrease the fail count by 1 (FC=0) in “cycle 4” where RSSI exists. In addition, when RSSI does not exist in cycles N-3 to N consecutively, the preprocessing unit (210) can increase the fail count by 1 consecutively for each measurement cycle (FC=1 to 4).

[0086] According to an embodiment, the quality diagnosis unit (220) may determine whether a communication error has occurred based on whether the fail count is greater than a predetermined number before diagnosing the quality of wireless communication based on the compensation RSSI derived through the preprocessing unit (210).

[0087] For example, in FIG. 3, the quality diagnosis unit (220) can determine whether the fail count is 4 or more at regular intervals. In addition, the quality diagnosis unit (220) can determine that a communication error has occurred in N cycles in which the fail count is 4 or more.

[0088] Figure 5 is a flowchart of a wireless communication quality diagnosis method according to one embodiment of the present invention.

[0089] 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).

[0090] In the wireless signal receiving step (S100), the communication unit (100) can perform wireless communication with the slave BMS (20) to receive a wireless signal containing battery information. For example, the communication unit (100) can receive a wireless signal containing battery information from the slave BMS (20).

[0091] According to an embodiment, in the wireless signal receiving step (S100), 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 a predetermined diagnostic condition is satisfied, the communication unit (100) provides the received wireless signal to the RSSI measurement unit (110).

[0092] In some embodiments, a predetermined diagnostic condition may correspond to a number of battery information unit packets being divided into a reference number or greater. For example, if the number of battery information unit packets received is greater than or equal to a reference number (e.g., 1,000), the communication unit (100) may provide wireless signals received thereafter to the RSSI measurement unit (110).

[0093] In the RSSI measurement step (S200), the RSSI measurement unit (110) can measure the RSSI of a wireless signal. At this time, the RSSI measured by the RSSI measurement unit (110) can be transmitted to the control unit (200).

[0094] Here, the Received Signal Strength Indicator (RSSI) is a measurement of the power present in the received wireless signal, and the unit of measurement for RSSI can be expressed in power level units [dBm]. For example, RSSI can be expressed as a 'negative value [dBm]', and the closer it is to '0 [dBm]', the stronger the signal can be.

[0095] In the RSSI preprocessing step (S300), the preprocessing unit (210) can perform preprocessing including averaging, missing value correction, and moving average on the RSSI to derive a compensated RSSI. Here, the compensated RSSI can be used to determine the quality of wireless communication.

[0096] For example, in the RSSI preprocessing step (S300), the preprocessing unit (210) can receive RSSI from the RSSI measurement unit (110) for each unit of time, and calculate the average value of RSSI for each unit of time (S310). If there is a missing value in the average value of the calculated RSSI, the preprocessing unit (210) can calculate the average of the average values ​​of RSSI calculated before and after the missing value to replace the missing value (S320). In addition, the preprocessing unit (210) can derive a compensated RSSI by applying a moving average filter to the average value of RSSI (S330).

[0097] Accordingly, the master BMS (10) according to one embodiment of the present invention can resolve time imbalance for a judgment target when judging wireless communication quality, can diagnose the quality of wireless communication even when a temporary communication failure occurs, and can reduce the influence of noise that may be included in a wireless signal to improve the reliability of data and the accuracy of judging wireless communication quality.

[0098] According to an embodiment, the RSSI preprocessing step (S300) may include a step of increasing or decreasing the fail count based on the presence or absence of RSSI received from the RSSI measurement unit (110) during a unit of time. For example, in the RSSI preprocessing step (S300), the preprocessing unit (210) may include a step of increasing the fail count by 1 if there is no RSSI received from the RSSI measurement unit (110) during a unit of time, and a step of decreasing the fail count by 1 if there is a compensation RSSI generated through the RSSI measurement unit (110) during a unit of time. At this time, in the wireless communication quality diagnosis step (S400), the quality diagnosis unit (220) may include a step (S410) of diagnosing that a communication error has occurred if the fail count is equal to or greater than a predetermined number.

[0099] 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 one embodiment of the present invention will be described in detail with reference to FIG. 6.

[0100] Referring to FIG. 6, in a wireless communication quality diagnosis step (S400) according to one embodiment of the present invention, a quality diagnosis unit (220) can diagnose the quality of wireless communication based on whether the compensation RSSI is equal to or greater than a preset reference value and / or falls within a preset range.

[0101] According to an embodiment, the wireless communication quality diagnosis step (S400) may include a step of diagnosing, by the quality diagnosis unit (220), that wireless communication is in a normal state if the compensation RSSI exceeds a first reference value, a step of diagnosing that wireless communication is in a dangerous state if a preliminary dangerous state in which the compensation RSSI is lower than the first reference value but higher than the second reference value is maintained for a predetermined period of time, and a step of diagnosing that wireless communication is in a defective state if a preliminary defective state in which the compensation RSSI is lower than the second reference value is maintained for a predetermined period of time. At this time, the first reference value and the second reference value may be determined based on a power level range that the compensation RSSI may have, and the first reference value is greater than the second reference value.

[0102] According to an embodiment, the wireless communication quality diagnosis step (S400) may include a step of counting the period during which the quality diagnosis unit (220) is maintained in the preliminary risk state and the preliminary defect state, respectively, to determine the risk state and the defect state, respectively.

[0103] 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 the value of the count of the preliminary defect state (hereinafter, “Fault Count”) and the value of the count of the preliminary danger state (hereinafter, “Warning Count”) are equal to or greater than a predetermined number by the quality diagnosis unit (220). Here, the Fault Count and the Warning Count may be integers greater than or equal to 0.

[0104] That is, in the wireless communication quality diagnosis step (S400), the quality diagnosis unit (220) can improve the accuracy of the diagnosis of the quality of wireless communication by finally performing a judgment on the quality of wireless communication when the result of counting the number of times in which the compensation RSSI is out of the reference range is greater than or equal to a predetermined number of times, that is, when the preliminary risk state or preliminary defect state is maintained for a predetermined period of time. For example, even when the compensation RSSI is less than or equal to the first reference value and greater than the second reference value, if the warning count is not greater than or equal to a predetermined number (e.g., 3), the wireless communication can be determined not to be in a 'dangerous state'.

[0105] According to an embodiment, the wireless communication quality diagnosis step (S400) may include a step of receiving a compensation RSSI from a preprocessing unit (210) by a quality diagnosis unit (220) (S420), a step of diagnosing that the quality of wireless communication is normal when the compensation RSSI exceeds a first reference value (S431), a step of increasing a warning count by 1 when the compensation RSSI is lower than or equal to the first reference value (S441), a step of diagnosing that the quality of wireless communication is in a dangerous state when the warning count is higher than or equal to a predetermined number (S442), a step of increasing a fault count by 1 when the compensation RSSI is lower than or equal to a second reference value that is lower than the first reference value (S451), and a step of diagnosing that the quality of wireless communication is in a defective state when the fault count is higher than or equal to a predetermined number (S453) (S454). Here, a predetermined number for the warning count and fault count can be preset by the user and stored in the storage unit (230).

[0106] 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 both 2.

[0107] In the above example, if the preprocessing unit (210) determines that the compensation 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'.

[0108] Alternatively, in the above example, if the preprocessing unit (210) determines that the compensation RSSI is -90 dBm, the quality diagnosis unit (220) may increase the warning count to 3, increase the fault count to 3, and then diagnose that the wireless communication is in a 'defective state'.

[0109] Meanwhile, the above-described method can be written as a program that can be executed on a computer, and can be implemented on a general-purpose digital computer that operates the program using a computer-readable recording medium. The computer-readable recording medium may include a storage medium such as a magnetic storage medium such as a ROM, RAM, USB, floppy disk, or hard disk, or an optical readable medium such as a CD-ROM or DVD.

[0110] The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. A communication unit that receives a wireless signal containing battery information; An RSSI measuring unit that measures the received signal strength (RSSI, Received Signal Strength Indicator) of the above wireless signal; A preprocessing unit that calculates an average for the RSSI for each measurement cycle and derives a compensation RSSI by calculating a moving average based on the averages for a predetermined number of measurement cycles based on each measurement cycle; and Including a quality diagnosis unit that diagnoses the quality of the wireless communication based on the above compensation RSSI. Battery management system.

2. In paragraph 1, The above communication department, If the number of unit packets divided into the above battery information is greater than or equal to the standard number, the wireless signal is transmitted to the RSSI measurement unit. Battery management system.

3. In paragraph 1, The above preprocessing unit, If a missing value for the RSSI occurs in the first measurement cycle during the above measurement cycle, Calculating the average for RSSI of the first measurement period as the average value of the first average before the first measurement period and the second average after the first measurement period, Battery management system.

4. In paragraph 1, The above preprocessing unit, If there is no RSSI received from the RSSI measurement unit for each of the above measurement periods, the fail count is increased by 1, and if there is RSSI received from the RSSI measurement unit for each of the above measurement periods, the fail count is decreased by 1. Battery management system.

5. In paragraph 4, The above quality diagnosis department, If the above fail count is greater than a certain number, it is diagnosed that a communication error has occurred. Battery management system.

6. In paragraph 1, The above quality diagnosis department, If the above compensation RSSI exceeds the first reference value, the quality of the wireless communication is diagnosed as normal. Battery management system.

7. In paragraph 1, The above quality diagnosis department, If the above compensation RSSI is maintained for a predetermined period of time in a preliminary risk state where it is lower than the first reference value and exceeds the second reference value that is lower than the first reference value, the quality of the wireless communication is diagnosed as being in a risk state. Battery management system.

8. In paragraph 1, The above quality diagnosis department, If the above compensation RSSI is maintained in a preliminary defective state below the second reference value for a predetermined period of time, the quality of the wireless communication is diagnosed as defective. Battery management system.

9. A step of the communication unit receiving a wireless signal containing battery information; A step for measuring the received signal strength (RSSI, Received Signal Strength Indicator) of the wireless signal by the RSSI measuring unit; A step of the preprocessing unit calculating an average for the RSSI for each measurement cycle, and calculating a moving average based on the average for a predetermined number of measurement cycles based on each measurement cycle to derive a compensation RSSI; and A quality diagnosis unit comprises a step of diagnosing the quality of the wireless communication based on the compensation RSSI. Method for diagnosing wireless communication quality.

10. In paragraph 9, The step of receiving the above wireless signal is: Including a step of transmitting the wireless signal to the RSSI measurement unit when the number of the battery information divided into unit packets is greater than or equal to a standard number. Method for diagnosing wireless communication quality.

11. In paragraph 9, The steps for deriving the above compensation RSSI are: Including a step of calculating an average for RSSI of the first measurement period as an average value of a first average before the first measurement period and a second average after the first measurement period, if a missing value for the RSSI occurs in the first measurement period during the above measurement period. Method for diagnosing wireless communication quality.

12. In paragraph 9, The steps for deriving the above compensation RSSI are: A step of increasing the fail count by 1 when there is no RSSI received from the RSSI measurement unit for each of the above measurement periods; and Including a step of decreasing the fail count by 1 when there is an RSSI received from the RSSI measurement unit for each of the above measurement periods. Method for diagnosing wireless communication quality.

13. In paragraph 12, The steps for diagnosing the quality of the above wireless communication are: Including a step of diagnosing that a communication error has occurred when the above fail count is greater than a predetermined number. Method for diagnosing wireless communication quality.

14. In paragraph 9, The steps for diagnosing the quality of the above wireless communication are: A step of diagnosing that the quality of the wireless communication is normal when the above compensation RSSI exceeds the first reference value; A step of increasing the warning count by 1 when the above compensation RSSI is less than or equal to the first reference value; A step of diagnosing that the quality of the wireless communication is at risk when the above warning count is greater than a predetermined number; a step of increasing the fault count by 1 when the above compensation RSSI is less than or equal to a second reference value that is less than the first reference value; and A step of diagnosing that the quality of the wireless communication is defective when the above fault count is greater than a predetermined number, Method for diagnosing wireless communication quality.

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