Battery monitoring system, transmitter for battery monitoring system, receiver for battery monitoring system, radio communication program, and radio communication method

Abstract

A battery monitoring system (100) comprises: a transmitter (40); and a receiver (30). The receiver comprises: a control unit (31) that performs control according to control information; a communication quality determination unit (32) that, when the control information is received, determines the communication quality of a communication channel used for transmission; and a reply unit (32) that sends back the results of control by the control unit in a case where the communication quality determined by the communication quality determination unit is favorable, but that does not send back the results of control in a case where the communication quality is unfavorable. The transmitter comprises an evaluation unit (42) that, in a case where the results of control are not sent back from the receiver after the transmission of the control information, evaluates that the communication quality of the communication channel selected when transmitting the control information is unfavorable.

Description

Battery monitoring system, transmitter for battery monitoring system, receiver for battery monitoring system, wireless communication program, and wireless communication method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2023-107030, filed on June 29, 2023, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a wireless device for a battery monitoring system, a battery monitoring system, a wireless communication program, and a wireless communication method.

[0003] Recently, there have been battery monitoring systems that transmit and receive battery information via wireless communication. In some of these battery monitoring systems, the slave device transmits information about the reception status along with the battery information to the master device. The master device then determines the communication quality of each communication channel based on the received information about the reception status and uses this information to select a communication channel for subsequent transmissions. Such a battery monitoring system is described, for example, in Patent Document 1.

[0004] Patent No. 6514694

[0005] In such a battery monitoring system, each time a slave unit transmits battery information, it also transmits information about the reception status, which increases the amount of communication data transmitted from the slave unit to the master unit. This increases the communication speed and increases the communication error rate.

[0006] The present disclosure has been made in consideration of the above circumstances, and its main purpose is to provide a battery monitoring system, a transmitter for the battery monitoring system, a receiver for the battery monitoring system, a wireless communication program, and a wireless communication method that can reduce the amount of communication data.

[0007] A first means for solving the above problem is a battery monitoring system that monitors a battery unit, comprising: a transmitter that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels; and a receiver that performs various controls in accordance with the control information and returns the control results, wherein the receiver comprises: a control unit that performs control in accordance with the control information; a communication quality determination unit that determines the communication quality of the communication channel used for transmission when receiving the control information; and a reply unit that replies with the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good, and the transmitter comprises an evaluation unit that evaluates the communication quality of the communication channel selected when transmitting the control information to be poor if the control result is not returned from the receiver after transmitting the control information.

[0008] In this way, if the communication quality is not good, the control result is not returned. This prevents a vicious cycle in which the amount of communication data increases in order to notify that the communication quality is poor, and prevents further deterioration of the communication quality.

[0009] A second means for solving the above problem is a battery monitoring system that monitors a battery unit, and includes a transmitter that transmits control information via wireless communication using a communication channel selected from a plurality of communication channels, and a receiver that performs various controls in accordance with the control information and returns the control results.In the receiver of the battery monitoring system, the transmitter includes an evaluation unit that evaluates that the communication quality of the communication channel selected when transmitting the control information is poor if the control result is not returned from the receiver after transmitting the control information, and the receiver includes a control unit that performs control in accordance with the control information, a communication quality determination unit that determines the communication quality of the communication channel used for transmission when receiving the control information, and a reply unit that replies with the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good.

[0010] In this way, if the communication quality is not good, the control result is not returned. This prevents a vicious cycle in which the amount of communication data increases in order to notify that the communication quality is poor, and prevents further deterioration of the communication quality.

[0011] A third means for solving the above problem is a battery monitoring system that monitors a battery unit, comprising: a transmitter that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels; and a receiver that performs various controls in accordance with the control information and returns the control results. In the transmitter of the battery monitoring system, the receiver comprises: a control unit that performs control in accordance with the control information; a communication quality determination unit that determines the communication quality of the communication channel used for transmission when receiving the control information; and a reply unit that replies with the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good. The transmitter also comprises an evaluation unit that evaluates the communication quality of the communication channel selected when transmitting the control information to be poor if the control result is not returned from the receiver after transmitting the control information.

[0012] In this way, if the communication quality is not good, the control result is not returned. This prevents a vicious cycle in which the amount of communication data increases in order to notify that the communication quality is poor, and prevents further deterioration of the communication quality.

[0013] A fourth means for solving the above problem is a battery monitoring system that monitors a battery unit, the battery monitoring system comprising: a transmitter that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels; and a receiver that performs various controls in accordance with the control information and returns the control results. The wireless communication program executed by the transmitter and receiver of the battery monitoring system causes the receiver to perform a control process that performs control in accordance with the control information; a communication quality determination process that determines the communication quality of the communication channel used for transmission when the control information is received; and a return process that returns the control result of the control process if the communication quality determined by the communication quality determination process is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good. The transmitter also causes the transmitter to perform an evaluation process that evaluates the communication quality of the communication channel selected when transmitting the control information as poor if the control result is not returned from the receiver after transmitting the control information.

[0014] In this way, if the communication quality is not good, the control result is not returned. This prevents a vicious cycle in which the amount of communication data increases in order to notify that the communication quality is poor, and prevents further deterioration of the communication quality.

[0015] A fifth means for solving the above problem is a battery monitoring system that monitors a battery unit, the battery monitoring system comprising: a transmitter that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels; and a receiver that performs various controls in accordance with the control information and returns the control results. In the wireless communication method implemented by the transmitter and receiver of the battery monitoring system, the receiver performs a control process that performs control in accordance with the control information; a communication quality determination process that determines the communication quality of the communication channel used for transmission when receiving the control information; and a return process that returns the control result of the control process if the communication quality determined by the communication quality determination process is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good. The transmitter performs an evaluation process that evaluates the communication quality of the communication channel selected when transmitting the control information as poor if the control result is not returned from the receiver after transmitting the control information.

[0016] In this way, if the communication quality is not good, the control result is not returned. This prevents a vicious cycle in which the amount of communication data increases in order to notify that the communication quality is poor, and prevents further deterioration of the communication quality.

[0017] In this way, if the communication quality is not good, the control result is not returned. This prevents a vicious cycle in which the amount of communication data increases in order to notify that the communication quality is poor, and prevents further deterioration of the communication quality.

[0018] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a block diagram showing a schematic configuration of a vehicle, Fig. 2 is a block diagram showing a configuration of a battery pack, Fig. 3 is a perspective view showing a schematic configuration of the battery pack, Fig. 4 is a flowchart showing a data communication flow, Fig. 5 is a flowchart showing a data communication flow, Fig. 6 is a flowchart showing a connection establishment process, Fig. 7 is a diagram showing frequency bands of communication channels, Fig. 8 is a diagram showing a data flow when a connection is established, Fig. 9 is a diagram showing a channel map, Fig. 10 is a flowchart showing a data communication flow of a second embodiment, Fig. 11 is a diagram showing a channel map of the second embodiment, Fig. 12 is a flowchart showing a flow of an abnormality determination process of a third embodiment, and Fig. 13 is a flowchart showing a flow of an abnormality determination process of a fourth embodiment.

[0019] Hereinafter, embodiments of a battery monitoring system, a transmitter, a receiver, a wireless communication program, and a wireless communication method according to the present disclosure will be described in detail with reference to the drawings. Note that, between the embodiments and modifications, the same or corresponding parts in the drawings are designated by the same reference numerals, and their descriptions will not be repeated in principle. Below, we will describe the application to a vehicle, but the present disclosure can also be applied to applications other than vehicles, such as drones and other flying objects, ships, construction machinery, agricultural machinery, etc.

[0020] (First embodiment) <Vehicle> Fig. 1 is a diagram that shows a schematic configuration of a vehicle 10. The vehicle 10 is an electrically powered vehicle such as an electric vehicle (EV), a hybrid vehicle (HV), or a plug-in hybrid vehicle (PHV). The vehicle 10 includes a battery pack 11 (shown as "Battery" in Fig. 1), a power control unit (hereinafter referred to as "PCU") 12 as a power conversion device, a motor 13 (shown as "MG" in Fig. 1) as an electric load, and a vehicle ECU 14 (shown as "ECU" in Fig. 1). Note that PCU is an abbreviation for "Power Control Unit," MG is an abbreviation for "Motor Generator," and ECU is an abbreviation for "Electronic Control Unit."

[0021] The battery pack 11 is mounted on the vehicle 10 as a driving power source for the vehicle 10. In Fig. 1, the battery pack 11 is disposed in, for example, a front compartment. However, the battery pack 11 may also be disposed in a rear compartment, under a seat, under the floor, or the like.

[0022] The battery pack 11 is a chargeable and dischargeable DC voltage source that includes a battery pack 20 (described later). The battery pack 11 supplies power to the electrical loads of the vehicle 10. The battery pack 11 also converts power via the PCU 12 and supplies the power to the motor 13. The battery pack 11 is also charged via the PCU 12.

[0023] The PCU 12 performs bidirectional power conversion between the battery pack 11 and the motor 13 in accordance with a control signal from the vehicle ECU 14. The PCU 12 includes, for example, an inverter that converts DC voltage from the battery pack 11 into AC voltage to drive the motor 13, and a converter that boosts the DC voltage supplied to the inverter to a voltage equal to or higher than the output voltage of the battery pack 11.

[0024] The motor 13 is an AC rotating electric machine, such as a three-phase AC synchronous motor with a permanent magnet embedded in the rotor. The motor 13 is driven by the PCU 12 to generate rotational driving force, which is transmitted to the drive wheels. Meanwhile, when braking the vehicle 10, the motor 13 operates as a generator and performs regenerative power generation. The electric power generated by the motor 13 is supplied to the battery pack 11 via the PCU 12 and stored in the battery pack 20.

[0025] The vehicle ECU 14 includes a CPU, ROM, RAM, input / output ports for inputting and outputting various signals, etc. The CPU loads a program stored in the ROM into the RAM and executes it. The program stored in the ROM describes the processing of the vehicle ECU 14. As an example of the main processing of the vehicle ECU 14, the vehicle ECU 14 receives information such as the voltage, current, SOC (State of Charge), and SOH (State of Health) of the battery pack 20 from the battery pack 11, and controls the PCU 12 to instruct the driving of the motor 13 and the charging and discharging of the battery pack 11.

[0026] <Battery Pack> The battery pack 11 will be described in detail. Fig. 2 is a block diagram showing the configuration of the battery pack 11, and Fig. 3 is a perspective view showing a schematic configuration of the battery pack 11. The battery pack 11 includes a battery pack 20, a battery monitoring system 100, and a housing 50 (shown by a dashed line) that houses them. The battery monitoring system 100 is a system that monitors and manages the battery pack 20 using wireless communication. The battery monitoring system 100 includes a plurality of battery monitoring devices 30 and a battery control device 40, and wireless communication is performed between these. This wireless communication uses a frequency band used for short-range communication, such as the 2.4 GHz band or the 5 GHz band.

[0027] <Battery Assembly> The battery assembly 20 includes a plurality of battery blocks 21 (sometimes referred to as a battery stack or battery module). The battery assembly 20 is configured by connecting these battery blocks 21 in series and / or in parallel. Each battery block 21 includes a plurality of battery cells 22. Each battery cell 22 is configured by a lithium-ion secondary battery, a nickel-metal hydride secondary battery, or the like. Note that a lithium-ion secondary battery is a secondary battery that uses lithium as a charge carrier, and may include not only a typical lithium-ion secondary battery with a liquid electrolyte, but also a so-called all-solid-state battery that uses a solid electrolyte. The battery block 21 is configured by connecting these battery cells 22 in series and / or in parallel via bus bars 23. Note that the presence of a battery block 21 is optional, and the battery assembly 20 may be configured by connecting the plurality of battery cells 22 in series and / or in parallel.

[0028] <Battery Monitoring Device> The battery monitoring device 30 will now be described. Note that each battery monitoring device 30 has a common configuration. The battery monitoring device 30 is also called a satellite battery module (SBM), and is provided for each battery block 21, i.e., for each of a plurality of battery cells 22. As shown in FIG. 2 , each battery monitoring device 30 includes a monitoring IC 31, a slave device-side wireless IC 32, and a slave device-side wireless antenna 33. The slave device-side wireless IC 32 is connected to the monitoring IC 31 by a wire. The slave device-side wireless IC 32 is also connected to the slave device-side wireless antenna 33 by a wire.

[0029] The monitoring IC 31, also called a cell supervising circuit (CSC), acquires (senses) battery information of each battery cell 22 constituting the battery block 21 via a physical quantity detection sensor (not shown) or the like. The physical quantity detection sensor is, for example, a voltage sensor, a temperature sensor, a current sensor, or the like, and the battery information includes, for example, voltage information, temperature information, current information, and the like of each battery cell 22. The object monitored by the battery monitoring device 30 may be the battery block 21 or the entire battery pack 20, and may be changed as desired.

[0030] When the monitoring IC 31 receives data (control data as control information) requesting acquisition and transmission of battery information, it acquires the battery information in accordance with the control data and transmits monitoring data (control results) including at least the battery information. The monitoring IC 31 may also have the function of performing a fault diagnosis (self-diagnosis) of the circuitry of the battery monitoring device 30, including itself, and including the diagnosis results in the monitoring data and transmitting the acquired battery information. Therefore, the monitoring IC 31 functions as a control unit that performs control in accordance with the control information.

[0031] The handset-side wireless IC 32 includes an RF circuit, a microcomputer, a front-end circuit, and other components (not shown) for wirelessly transmitting and receiving data. The handset-side wireless IC 32 has a transmission function that modulates data and oscillates at the frequency of an RF signal. At the same time, the handset-side wireless IC 32 has a reception function that demodulates received data. RF is an abbreviation for "radio frequency."

[0032] The slave-side wireless IC 32 modulates the monitoring data including the battery information received from the monitoring IC 31 and transmits it to the battery control device 40 via the slave-side wireless antenna 33. At this time, the slave-side wireless IC 32 adds data necessary for wireless communication, such as communication control information, to the monitoring data including the battery information and transmits it. The data necessary for wireless communication includes, for example, an identifier (ID) and an error detection code. The slave-side wireless IC 32 also has functions such as determining the data size, communication format, and schedule of communication between the battery monitoring device 30 and the battery control device 40, and detecting errors.

[0033] The slave-side wireless IC 32 also receives and demodulates data wirelessly transmitted from the battery control device 40 via the slave-side wireless antenna 33. When the slave-side wireless IC 32 receives control data including, for example, a request to acquire and transmit battery information, it transmits (transfers) the control data via a wired connection to the monitoring IC 31. When the slave-side wireless IC 32 receives monitoring data including battery information from the monitoring IC 31 in response to the request, it modulates response data including the monitoring data and wirelessly transmits the response data to the battery control device 40 via the slave-side wireless antenna 33.

[0034] The handset side wireless antenna 33 converts the RF signal, which is an electrical signal, into radio waves and radiates it into space, and also receives the radio waves propagating through space and converts them into an electrical signal.

[0035] <Battery Control Device> The battery control device 40 is also called a battery ECU or a BMU (Battery Management Unit). The battery control device 40 is configured to be able to wirelessly communicate with each battery monitoring device 30.

[0036] 2, the battery control device 40 includes a battery control MCU 41, a base unit side wireless IC 42, and a base unit side wireless antenna 43. The base unit side wireless IC 42 is connected to the battery control MCU 41 by a wire. The base unit side wireless IC 42 is also connected to the base unit side wireless antenna 43 by a wire.

[0037] The battery control MCU 41 is configured with a microcontroller unit (microcontroller unit) including a CPU, ROM, RAM, an input / output interface, etc. The CPU of the battery control MCU 41 loads a program stored in the ROM into the RAM and executes it. The program stored in the ROM contains, for example, processes related to battery control.

[0038] As an example of its main processing, the battery control MCU 41 transmits control data to the battery monitoring device 30 requesting the acquisition and transmission of battery information. Furthermore, the battery control MCU 41 performs various processes related to monitoring the battery pack 20, battery block 21, and battery cells 22 based on monitoring data including battery information received from the battery monitoring device 30. For example, the battery control MCU 41 may transmit monitoring results (monitoring data) to the vehicle ECU 14, which is a higher-level ECU. In this case, the battery control MCU 41 may calculate the SOC and / or SOH based on the battery information and transmit battery information including the calculated SOC and SOH to the vehicle ECU 14. Furthermore, the battery control MCU 41 controls relay switches that switch the energized and de-energized states of the battery pack 20, the PCU 12, and the motor 13 based on the monitoring results. Furthermore, the battery control MCU 41 may transmit an equalization signal to equalize the voltages of the battery cells 22. In this embodiment, the vehicle ECU 14 issues instructions to the PCU 12 to control the charging and discharging of the battery pack 20, but the battery control MCU 41 may also be configured to perform this function. As described above, the battery control MCU 41 monitors and manages the battery pack 20, the battery block 21, and the battery cells 22.

[0039] The master-side wireless IC 42 includes an RF circuit, a microcomputer, a front-end circuit, and the like (not shown) for wirelessly transmitting and receiving data, similar to the slave-side wireless IC 32. The master-side wireless IC 42 has a transmission function and a reception function, similar to the slave-side wireless IC 32.

[0040] The base unit side wireless IC 42 demodulates the received monitoring data including battery information via the base unit side wireless antenna 43 and transmits the demodulated data to the battery control MCU 41. The base unit side wireless IC 42 also modulates the control data received from the battery control MCU 41 with data necessary for wireless communication, such as communication control information, and transmits the modulated data to the battery monitoring device 30 via the base unit side wireless antenna 43. The data necessary for wireless communication includes, for example, an identifier (ID) and an error detection code. The base unit side wireless IC 42 also has functions such as determining the data size, communication format, and schedule of communication between the battery monitoring device 30 and the battery control device 40, and detecting errors.

[0041] The base unit side wireless antenna 43 has the same configuration and function as the slave unit side wireless antenna 33. That is, the base unit side wireless antenna 43 converts an RF signal, which is an electrical signal, into a radio wave and radiates it into space, and also receives the radio wave propagating through space and converts it into an electrical signal.

[0042] <Housing> The housing 50 is made of a conductive material such as metal. The housing 50 is formed in the shape of a metal box, and has a substantially rectangular parallelepiped shape. Note that the housing 50 may be partially or entirely made of a non-conductive material such as resin. The housing 50 houses the battery pack 20, the battery monitoring device 30, and the battery control device 40.

[0043] Here, the arrangement of the battery pack 20, battery monitoring device 30, and battery control device 40 will be briefly described with reference to Figure 3. The bottom surface of the housing 50 is the mounting surface for the vehicle 10. As shown in Figure 3, inside the substantially rectangular parallelepiped housing 50, multiple battery blocks 21 that make up the battery pack 20 are arranged side by side in the longitudinal direction (X direction in Figure 3). In each battery block 21, the battery cells 22 that make up the battery block 21 are arranged so as to be stacked in the lateral direction of the housing 50 (Y direction in Figure 3).

[0044] The battery monitoring device 30 and bus bars 23 are disposed on the top surface of each battery block 21 (the surface on the +Z direction side in FIG. 3 ) and secured with screws or the like. The battery control device 40 is disposed at the very end in the longitudinal direction (X direction). In this case, it is attached to the side of one of the battery blocks 21 (the battery block 21 at the end in the X direction in this embodiment) so that the circuit board on which the battery control device 40 is disposed is vertical. It is desirable that the parent unit wireless antenna 43 be disposed so that it protrudes above the top surface of the battery block 21.

[0045] The arrangement of the battery pack 20, battery monitoring device 30, and battery control device 40 shown in Figure 3 is one example and may be changed as desired. In addition, in this embodiment, the battery pack 20 and the battery monitoring system 100 are housed inside the housing 50, but a portion of them may be located outside the housing 50. Furthermore, the housing 50 may not be provided, and the battery pack 20 and other components may be directly attached to a vehicle body frame or the like. In other words, the vehicle body frame may replace the housing 50.

[0046] <Wireless Communication> Next, wireless communication (wireless communication method) between the battery monitoring device 30 and the battery control device 40 will be described with reference to Figures 4 to 6. Figures 4 and 5 are diagrams showing an example of a communication sequence for data communication between the battery monitoring device 30 and the battery control device 40. This communication sequence is repeated at predetermined intervals or is performed according to a predetermined communication schedule. The battery monitoring device 30 and the battery control device 40 execute wireless communication programs stored in their respective storage devices (ROM, etc.), thereby performing each process.

[0047] 4 to 6 explain wireless communication between one battery monitoring device 30 and a battery control device 40. The battery monitoring device 30 that will communicate is determined by a communication schedule or the like. In FIGS. 4 to 6, the monitoring IC 31 is indicated as MIC31, the slave device side wireless IC 32 is indicated as WIC32, the battery control MCU 41 is indicated as MCU41, and the master device side wireless IC 42 is indicated as WIC42. FIG. 6 is a diagram showing an example of the connection establishment process (step S10) shown in FIG. 4.

[0048] As shown in FIG. 4, the slave-side wireless IC 32 of the battery monitoring device 30 and the master-side wireless IC 42 of the battery control device 40 execute a process for establishing a connection (step S10).

[0049] The connection establishment process of step S10 will now be described with reference to Fig. 6. As shown in Fig. 6, the master-side wireless IC 42 of the battery control device 40 executes a scanning operation (a slave-side detection operation) (step S11), and the slave-side wireless IC 32 executes an advertising operation (a connection information transmission operation) (step S12). The scanning operation may start earlier than or at approximately the same timing as the advertising operation. It may also start later than the advertising operation.

[0050] The advertising operation is an operation in which the slave-side wireless IC 32 transmits an advertisement packet (ADV_PKT) by broadcast communication in order to notify the master-side wireless IC 42 of the battery control device 40 of its own existence. The advertisement packet includes ID information of the slave-side wireless IC 32 (battery monitoring device 30) and the battery control device 40.

[0051] In this advertising operation, a communication channel for establishing a connection is used among a plurality of communication channels. The communication channel is a frequency band used in short-range communication, for example, a 2.4 GHz band, divided by a predetermined bandwidth (for example, 2 MHz), and in this embodiment, as shown in FIG. 7, it is divided into 40 channels, 0ch to 39ch. The communication channel for establishing a connection is a predetermined communication channel (for example, 37ch to 39ch) among the 40 channels. Meanwhile, the channels other than the communication channel for establishing a connection (for example, 0ch to 36ch) among the plurality of communication channels are communication channels for transmitting data, which will be described later.

[0052] In the advertising operation, as shown in Fig. 8, advertisement packets are transmitted at predetermined intervals using multiple (three in this embodiment) communication channels for connection establishment. As a result, even if communication failure occurs in one of the communication channels for connection establishment, communication can be performed using the other communication channels for connection establishment. For this reason, the three communication channels for connection establishment are set with frequency bands as far apart as possible to prevent interference with each other (see Fig. 7). In addition, it is desirable that the communication channels for connection establishment be set so as not to overlap with frequency bands used by other devices, etc.

[0053] Returning to the description of the connection establishment process, as shown in Fig. 6, when the master-side wireless IC 42 of the battery control device 40 detects an advertisement packet, i.e., the slave-side wireless IC 32, by a scanning operation, it transmits a connection request (CONNECT_REQ) to the detected slave-side wireless IC 32 (step S13).

[0054] When the slave-side wireless IC 32 receives the connection request, a wireless communication path connection is established between one battery monitoring device 30 and the battery control device 40 (step S14). Once the connection is established, the slave-side wireless IC 32 of the battery monitoring device 30 stops transmitting advertisement packets. The slave-side wireless IC 32 periodically transmits advertisement packets until the connection is established.

[0055] This connection establishment process is executed, for example, at startup. Startup refers to, for example, when operating power is supplied. In a configuration in which power is constantly supplied from the battery block 21, startup occurs during the manufacturing process of the vehicle 10 or after a part is replaced at a repair shop. Startup may also occur when a startup signal, such as an IG signal output when the ignition switch is turned on, is input. For example, startup occurs when the ignition switch is switched from off to on by a user operation. Furthermore, when the ignition switch is off, the battery monitoring device 30 and the battery control device 40 enter a sleep state (standby mode) but are activated intermittently. The connection establishment process may also be executed during this intermittent startup.

[0056] At the time of startup, a connection establishment process is executed between the battery control device 40 and all of the battery monitoring devices 30 that are targets for connection with the battery control device 40 via wireless communication.

[0057] Furthermore, when the battery monitoring device 30 and the battery control device 40 are disconnected, they again execute the connection establishment process (step S10). That is, they execute reconnection. The battery control device 40 executes reconnection (establishment of connection) with the disconnected battery monitoring device 30 while continuing data communication with the remaining battery monitoring devices 30 with which connections have been established. For example, a disconnection occurs due to a deterioration in the communication environment.

[0058] Furthermore, once a wireless communication connection is established, the connection establishment process is skipped and the subsequent processes are carried out unless the connection is disconnected. In other words, once a wireless communication connection is established in step S10, the battery control device 40 periodically performs data communication with the battery monitoring device 30 (the processes of steps S20 to S33).

[0059] More specifically, as shown in FIG. 4 , the battery control MCU 41 of the battery control device 40 transmits control data (control information) including a request to acquire and a request to transmit monitoring data, including battery information, to the battery monitoring device 30 with which the connection has been established (step S20). Upon receiving the control data, the base station wireless IC 42 generates transmission data by adding data necessary for wireless communication, such as communication control information, to the control data (step S21). At the same time, the base station wireless IC 42 selects one of the communication channels for data transmission (e.g., channels 0 to 36) (step S22). In this case, as shown in FIG. 9 , the base station wireless IC 42 selects a communication channel from the available communication channels for data transmission by referring to a channel map in which the status of each communication channel is set as available or unavailable (unselectable; the same applies below). The method for setting each communication channel as available or unavailable will be described later.

[0060] Then, the base station side wireless IC 42 wirelessly transmits the transmission data to the slave station side wireless IC 32 via the base station side wireless antenna 43 (step S23). At this time, the base station side wireless IC 42 wirelessly transmits the data to the slave station side wireless IC 32 using the selected communication channel for data transmission.

[0061] When the slave-side wireless IC 32 of the battery monitoring device 30 receives the transmission data via the slave-side wireless antenna 33, it determines whether the communication quality of the communication channel used to transmit the transmission data was good (step S24). In other words, the slave-side wireless IC 32 determines whether the transmission data was successfully received.

[0062] In step S24, the slave-side wireless IC 32 may determine that the communication quality is poor (that is, the signal was not properly received) if, for example, the received signal strength (RSSI: Received Signal Strength Indicator) is equal to or lower than a predetermined strength threshold. The slave-side wireless IC 32 may also determine the communication quality using, for example, a cyclic redundancy check (CRC). The slave-side wireless IC 32 may also determine the communication quality based on, for example, whether a packet error rate is equal to or lower than a predetermined error rate. The slave-side wireless IC 32 may also determine the communication quality based on the communication time from when the master-side wireless IC 42 transmits the data to when the slave-side wireless IC 32 receives the data. When transmitting data divided into packets, the slave-side wireless IC 32 may also determine the communication quality based on the variation in the interval between when one packet arrives and when the next packet arrives. The communication quality may also be determined based on a signal-to-noise ratio (SNR). Alternatively, other known methods may be employed, or a combination of these methods may be used to determine the communication quality based on the results of the determination. As described above, the slave-side wireless IC 32 of this embodiment functions as a communication quality determination unit that, when receiving control data, determines the communication quality of the communication channel used for transmission. The process of step S24 corresponds to a communication quality determination process that, when receiving control information, determines the communication quality of the communication channel used for transmission.

[0063] If the communication quality is good, the determination result of step S24 is affirmative, and if the communication quality is poor, the determination result of step S24 is negative. If the determination result of step S24 is affirmative, that is, if the data was received normally, the slave-side wireless IC 32 transmits the control data included in the received transmission data to the monitor IC 31 (step S25).

[0064] When the monitoring IC 31 receives the control data, it acquires (senses) battery information (step S26).The monitoring IC 31 may also perform a circuit fault diagnosis.

[0065] Next, the monitoring IC 31 transmits monitoring data including the battery information to the slave-side wireless IC 32 (step S27). At this time, the monitoring data including the diagnosis result may be transmitted together with the battery information.

[0066] Upon receiving the monitoring data from the monitoring IC 31, the slave-side wireless IC 32 generates transmission data including the monitoring data, i.e., response data, and wirelessly transmits (responses) the data to the master-side wireless IC 42 via the slave-side wireless antenna 33 (step S28). At this time, similar to the processing of the master-side wireless IC 42 in step S21, data necessary for wireless communication, such as communication control information, is added to the response data. Furthermore, the slave-side wireless IC 32 selects the same communication channel as the communication channel used when receiving the transmission data transmitted by the master-side wireless IC 42, and wirelessly transmits the data to the master-side wireless IC 42. That is, the slave-side wireless IC 32 transmits the data using the communication channel for data transmission selected in step S22. Therefore, the communication channel for data transmission corresponds to the communication channel for battery information transmission.

[0067] Conventionally, when the slave-side wireless IC 32 determines the communication quality, it always returns the determination result (communication quality) to the master-side wireless IC 42. In other words, when the slave-side wireless IC 32 cannot normally receive the transmitted data (when it determines that the communication quality is poor), it returns the determination result to the master-side wireless IC 42. Then, the master-side wireless IC 42 determines the communication quality for each communication channel based on the determination result.

[0068] However, as described above, even when the transmitted data could not be received normally (when the communication quality was poor), the determination result was returned to the base-side wireless IC 42, which resulted in a vicious cycle in which the amount of communication data increased and the communication quality further deteriorated, resulting in problems such as a further slowdown in the communication speed and an increase in the communication error rate.

[0069] Therefore, in this embodiment, if the determination result in step S24 is negative (if the communication quality is poor), the slave-side wireless IC 32 ends the data communication in that cycle and does not respond (reply) to the master-side wireless IC 42. This makes it possible to prevent the amount of communication data on a communication channel from increasing when the communication quality of the communication channel being used is poor.

[0070] As described above, the slave-side wireless IC 32 of this embodiment functions as a reply unit that returns monitoring data (control results) when the communication quality is good, but does not return monitoring data when the communication quality is not good. The processes of steps S24 to S38 correspond to the reply process.

[0071] 5, after transmitting the transmission data in step S23, the base unit wireless IC 42 determines whether or not response data has been returned from the slave unit wireless IC 32, which is the transmission partner (step S29). Specifically, after transmitting the transmission data in step S23, the base unit wireless IC 42 determines whether or not response data has been received within a predetermined time period.

[0072] If the determination result in step S24 is negative, meaning that the slave-side wireless IC 32 has not returned response data, the determination result in step S29 will also be negative. Also, even if the determination result in step S24 is positive, meaning that the slave-side wireless IC 32 has returned response data, if the master-side wireless IC 42 was unable to receive the response data due to a communication failure or the like, the determination result in step S29 will also be negative.

[0073] If the judgment result of step S29 is negative, i.e., if the response data cannot be received, the parent device side wireless IC 42 evaluates the communication quality of the communication channel used when transmitting the transmission data to the child device side wireless IC 32, i.e., the communication channel for data transmission selected in step S22, and stores the evaluation result in the channel map (step S30).

[0074] Specifically, in step S30, the base station wireless IC 42 determines that the communication quality of the communication channel for data transmission selected in step S22 is poor. In this embodiment, if the base station wireless IC 42 determines that the communication quality is poor, it stores the status of the communication channel as unusable (unselectable) in the channel map from the next time onward. As a result, the communication channel will not be selected in step S22 from the next time onward. The base station wireless IC 42 then terminates data communication for that period.

[0075] Therefore, in the present embodiment, if the base station wireless IC 42 transmits the control data and no monitoring data is returned from the battery monitoring device 30, the base station wireless IC 42 functions as an evaluation unit that evaluates the communication quality of the communication channel selected when transmitting the control data as poor. The process of step S30 corresponds to the evaluation process.

[0076] If the determination result in step S29 is positive, i.e., if response data has been returned, the master-side wireless IC 42 determines whether the communication quality of the communication channel used to transmit the response data was good (step S31). In step S31, the master-side wireless IC 42 determines the communication quality of the used communication channel by performing the same process as in step S24. If the determination result is negative (if the communication quality is poor), the process proceeds to step S30.

[0077] On the other hand, if the determination result in step S31 is positive, i.e., if the data was received normally (if the communication quality is good), the base station wireless IC 42 transmits the monitoring data included in the received response data to the battery control MCU 41 (step S32). The battery control MCU 41 executes a predetermined process based on the monitoring data (step S33). Then, the base station wireless IC 42 ends the data communication for that period.

[0078] As described above, the battery control device 40 periodically performs the above-described data communication with the battery monitoring device 30 with which a connection has been established.

[0079] The battery monitoring system 100, the battery monitoring device 30, the battery control device 40, the wireless communication program, and the wireless communication method of the above-described embodiments provide the following advantages.

[0080] When the battery monitoring device 30, which is a receiver, receives transmission data including control data (control information) from the battery control device 40, it determines the communication quality of the communication channel used for the transmission, and if the communication quality is good, it returns response data including the monitoring data (control result), but if the communication quality is not good, it does not return response data. This prevents the battery monitoring device 30 from returning communication quality data to the battery control device 40 to notify that the communication quality is poor, thereby preventing the amount of communication data from increasing and further deteriorating the communication quality.

[0081] Furthermore, if response data including monitoring data (control results) is not returned from the battery monitoring device 30 after the battery control device 40, which is a transmitter, transmits transmission data including control data (control information), the battery control device 40 evaluates that the communication quality of the communication channel selected when transmitting the transmission data is poor. Specifically, if the master-side wireless IC 42 does not receive response data within a predetermined time after transmitting the transmission data in step S23, the master-side wireless IC 42 evaluates that the communication quality of the communication channel is poor. This allows the battery monitoring device 30 to indirectly notify the battery control device 40 that the communication quality is poor without directly notifying the battery control device 40 via wireless communication.

[0082] Furthermore, the battery control device 40 stores in the channel map any communication channel whose communication quality has been determined to be poor, as unavailable (unselectable) for subsequent data communications, thereby preventing the use of communication channels with poor communication quality from the next time onward.

[0083] The communication channels include a communication channel for establishing a wireless communication connection and a communication channel for transmitting data used to exchange battery information. When the communication channel for transmitting data is used, the battery control device 40 evaluates the communication channel. This prevents the communication channel for establishing a connection from becoming unavailable.

[0084] The battery monitoring device 30 selects the same communication channel that was used when it received the transmission data sent by the battery control device 40, and returns the response data to the battery control device 40. In other words, the response data is returned using a communication channel with good communication quality. This prevents the communication quality of the communication channel with poor communication quality from being further deteriorated by the response data when a communication channel with poor communication quality is used.

[0085] Second Embodiment A second embodiment will be described in which the configuration of the battery monitoring system 100 of the first embodiment is partially modified.

[0086] The flow of data communication processing in the second embodiment will be described with reference to Fig. 10. Note that the same processes as those in the first embodiment are denoted by the same reference numerals, and explanations and drawings will be omitted. The description will focus on the processing in the second embodiment.

[0087] In the second embodiment, if the judgment result of step S29 is negative, or if the judgment result of step S31 is negative, the parent device side wireless IC 42 evaluates the communication quality of the communication channel used when transmitting the transmission data to the child device side wireless IC 32, i.e., the communication channel for data transmission selected in step S22, and updates the channel map (step S130).

[0088] In step S130, the base station wireless IC 42 determines that the communication quality of the communication channel for data transmission selected in step S22 is poor, and adds 1 to the number of times the communication quality of the communication channel has been determined to be poor. This number of times is stored in association with each communication channel in the channel map, as shown in FIG. 11 .

[0089] The base station wireless IC 42 then determines whether the number of failures after incrementing by one is equal to or greater than a predetermined threshold (step S131). The threshold may be any value, but in the third embodiment, it is set to "5." If the determination result is positive, the base station wireless IC 42 stores the status of the communication channel as unusable (unselectable) in the channel map (step S132). For example, if the number of failures is five or more, as in the case of communication channels ch1, ch12, ch23, and ch34 shown in FIG. 11, the status of the communication channel becomes unusable. As a result, the communication channel will not be selected in step S22 from the next time onward. The base station wireless IC 42 then terminates data communication for that period.

[0090] If the result of this determination is negative, the base unit wireless IC 42 ends the data communication in that period.

[0091] The second embodiment provides the following effects.

[0092] The external environment may cause poor communication quality. For example, poor communication quality is likely to occur when there is a lot of external noise or when the vehicle 10 vibrates significantly due to road conditions or other factors. In such cases, if all communication channels with poor communication quality were immediately made unselectable, there is a risk that too many communication channels would become unselectable, leaving little room for choice. Therefore, the number of times that poor communication quality is determined to be poor is stored, and a channel is made unselectable (unusable) only when the number of times exceeds a predetermined threshold. This reduces the number of unselectable communication channels.

[0093] In the second embodiment, the count threshold may be changed arbitrarily. The battery control device 40 may also include a threshold setting unit that changes the count threshold depending on the vehicle state or the communication speed. For example, the master wireless IC 42 may increase the count threshold (e.g., from "5" to "7") when the vehicle speed, which is a vehicle state, is equal to or greater than a predetermined speed. This prevents the number of communication channels from being unnecessarily designated as unselectable even when the vehicle 10 moves at high speed, increasing the amount of vibration transmitted from the vehicle 10 to the battery pack 11 and predicting a deterioration in communication quality (communication environment). The vehicle speed may be acquired directly from a vehicle speed sensor or indirectly via the battery control MCU 41.

[0094] Furthermore, the base station wireless IC 42 may increase the number threshold when the communication speed is set to a predetermined value or higher. In other words, increasing the communication speed increases the possibility that the communication quality will be poor, but in this case, it is possible to prevent an increase in the number of communication channels that are unnecessarily made unselectable.

[0095] Furthermore, when the vehicle 10 is traveling in an environment with a lot of external noise, for example, when the vehicle 10 is traveling near a radio tower, the base station wireless IC 42 may change the frequency threshold to increase. This prevents an increase in the number of communication channels that are unselectable even when a deterioration in communication quality (communication environment) is predicted due to traveling in an environment with a lot of external noise. Whether or not the vehicle 10 is traveling in an environment with a lot of external noise may be obtained indirectly via the battery control MCU 41, or the external noise may be measured directly.

[0096] In the above modification, the base unit wireless IC 42 functions as the threshold setting unit, but the battery control MCU 41 may also function as the threshold setting unit. In this case, the battery control MCU 41 may notify the base unit wireless IC 42 of the number threshold.

[0097] Third Embodiment A third embodiment will be described in which the configuration of the battery monitoring system 100 of the first embodiment is partially modified.

[0098] The battery control device 40 of the third embodiment is configured to perform data communication with multiple battery monitoring devices 30, and is configured to determine that some abnormality has occurred in the battery monitoring system 100 or the battery control device 40 if response data is not returned multiple times in succession from all of the battery monitoring devices 30.

[0099] The flow of the system abnormality determination process in the third embodiment will be described in detail with reference to Fig. 12. The system abnormality determination process is executed by the master-side wireless IC 42 at predetermined intervals, more specifically at each data communication interval.

[0100] First, the base unit wireless IC 42 reads the number of communication errors and determines whether the number of communication errors is greater than "0" (step S201). The number of communication errors indicates the number of times that communication quality was determined to be poor in the data communication described with reference to FIGS. 4 and 5, and is stored in the base unit wireless IC 42 or the like. Specifically, the number of times that communication quality was determined to be poor in step S30. Note that the number of times the connection establishment process (step S10) was not performed normally, i.e., the number of times a connection could not be established, may also be included.

[0101] If the determination result is positive, the base station wireless IC 42 increments the communication count counter by 1 to update its value (step S202). The communication count counter indicates the number of times data communication (the processing of step S203) has been performed since the number of communication errors became 1 or more, and is stored in the base station wireless IC 42 or the like.

[0102] If the determination result in step S201 is negative, or after the processing of step S202, the processing related to the data communication (processing of steps S20 to S33) described with reference to Figures 4 and 5 is performed (step S203). Note that if a connection has already been established, the connection establishment processing (step S10) is skipped and the processing related to the data communication is performed.

[0103] After the data communication process is completed, the base station wireless IC 42 determines whether a communication error has occurred in the data communication (step S204). Specifically, if the communication quality is determined to be poor in step S30, the base station wireless IC 42 determines that a communication error has occurred. Note that the base station wireless IC 42 may also determine that a communication error has occurred if the connection establishment process is not performed normally.

[0104] If the determination result in step S204 is positive, the master-side wireless IC 42 adds 1 to the number of communication errors to update the value (step S205). Next, the master-side wireless IC 42 determines whether the updated number of communication errors is greater than a predetermined abnormality determination threshold (step S206). The abnormality determination threshold is a value equal to or greater than 2, and is 5 in this embodiment.

[0105] If the determination result is positive, the master-side wireless IC 42 sets a system abnormality flag to "1" (step S207), indicating that some abnormality has occurred in the battery monitoring system 100 or the battery control device 40. Then, the master-side wireless IC 42 notifies an external host ECU (such as the vehicle ECU 14) that an abnormality has occurred in the battery monitoring system 100 or the battery control device 40 (step S208). Then, the series of processes ends.

[0106] On the other hand, if the determination result in step S204 or step S206 is negative, the master-side wireless IC 42 determines whether the communication count counter is smaller than a set value (step S209). If the determination result is positive, the process ends. The set value is, for example, 5.

[0107] On the other hand, if the determination result in step S209 is negative, the master-side wireless IC 42 initializes the communication count counter and the communication error count, i.e., sets them to "0" (step S210). In other words, if no communication error equal to or greater than the abnormality determination threshold occurs between the time when a communication error occurs and the time when the communication count counter reaches or exceeds the set value, the master-side wireless IC 42 initializes the communication count counter as being normal.

[0108] According to the third embodiment, if response data is not returned multiple times consecutively within a certain period of time, it is determined that some abnormality has occurred in the battery monitoring system 100 or the battery control device 40, making it possible to discover an abnormality in the battery monitoring system 100 or the battery control device 40. Therefore, the battery control device 40 of this embodiment functions as an abnormality determination unit.

[0109] Fourth Embodiment A fourth embodiment will be described in which the configuration of the battery monitoring system 100 of the first embodiment is partially modified.

[0110] The battery control device 40 of the fourth embodiment is configured to perform data communication with multiple battery monitoring devices 30, and is configured to determine that some abnormality has occurred in a specific battery monitoring device 30 if response data is not returned from that specific battery monitoring device 30 multiple times in succession.

[0111] The flow of the slave unit abnormality determination process in the fourth embodiment will be described in detail with reference to Fig. 13. The slave unit abnormality determination process is executed by the master unit wireless IC 42 at predetermined intervals, more specifically at each data communication interval.

[0112] First, the base-side wireless IC 42 selects a battery monitoring device 30 as a communication partner from among the plurality of battery monitoring devices 30 with which it can communicate, in a predetermined order (step S301). Then, the base-side wireless IC 42 reads the number of handset communication errors for the selected battery monitoring device 30 and determines whether the number of handset communication errors is greater than "0" (step S302). The number of handset communication errors is stored for each battery monitoring device 30 and indicates the number of times that communication quality was determined to be poor for each battery monitoring device 30 in the data communication described with reference to FIGS. 4 and 5 . Specifically, the number of times that communication quality was determined to be poor for each battery monitoring device 30 in step S30. It should be noted that the number of times the connection establishment process (step S10) was not performed normally, i.e., the number of times a connection could not be established, may also be included.

[0113] If the determination result is positive, the base-side wireless IC 42 increments the slave communication count counter of the battery monitoring device 30 selected in step S301 by one to update the value (step S303). The slave communication count counter is stored for each battery monitoring device 30 and indicates the number of times data communication (the processing of step S304) has been performed with the battery monitoring device 30 selected in step S301 since the number of slave communication errors became 1 or more.

[0114] If the determination result in step S302 is negative, or after the processing of step S303, the processing related to data communication (processing of steps S20 to S33) described with reference to Figures 4 and 5 is performed (step S304). Note that if a connection has already been established, the connection establishment processing (step S10) is skipped and the processing related to data communication is performed.

[0115] After the data communication process is completed, the base-side wireless IC 42 determines whether a communication error has occurred with the battery monitoring device 30, which is the communication partner in the data communication (step S305). Specifically, if it is determined in step S30 that the communication quality is poor, it is determined that a communication error has occurred. Note that it may also be determined that a communication error has occurred if the connection establishment process is not performed normally.

[0116] If the determination result in step S305 is positive, the master-side wireless IC 42 adds 1 to the number of slave-unit communication errors of the battery monitoring device 30 selected in step S301, and updates the value (step S306). Next, the master-side wireless IC 42 determines whether the updated number of slave-unit communication errors is greater than a predetermined slave-unit abnormality determination threshold (step S307). The slave-unit abnormality determination threshold is a value equal to or greater than 2, and is 5 in this embodiment.

[0117] If the determination result is positive, the master-side wireless IC 42 sets the slave-side abnormality flag to "1" (step S308), indicating that some abnormality has occurred in the battery monitoring device 30 of the communication partner (the partner selected in step S301).The master-side wireless IC 42 then notifies an external host ECU (such as the vehicle ECU 14) that an abnormality has occurred in the battery monitoring device 30 (step S309).At this time, the master-side wireless IC 42 may also notify the identification number (ID) of the communication partner's battery monitoring device 30.Then, the series of processes ends.

[0118] On the other hand, if the determination result in step S305 or step S307 is negative, the master-side wireless IC 42 determines whether the slave-side communication counter is smaller than a set value (step S310). The set value is an arbitrary value, for example, 5. If the determination result is positive, the series of processes ends.

[0119] On the other hand, if the determination result in step S310 is negative, the master-side wireless IC 42 initializes the slave-device communication count counter and the slave-device communication error count, i.e., sets them to "0" (step S311). In other words, if no communication error equal to or greater than the slave-device abnormality determination threshold occurs between the time a communication error occurs and the time the slave-device communication count counter reaches or exceeds the set value, the master-device wireless IC 42 initializes the counter as not being abnormal.

[0120] According to the fourth embodiment, if response data is not returned from a specific battery monitoring device 30 multiple times in succession, it is determined that some abnormality has occurred in the specific battery monitoring device 30, making it possible to discover an abnormality in the battery monitoring device 30. Thus, the battery control device 40 of this embodiment functions as an abnormality determination unit.

[0121] (Modification) The configuration of the battery monitoring system 100 in the above embodiment may be partially modified as follows. A modification with partial modifications will be described.

[0122] In the above embodiment, the base unit wireless IC 42 has the function of the evaluation unit, but the battery control MCU 41 may have the function of the evaluation unit. Also, the communication channel may be selected by the battery control MCU 41. Similarly, the setting of communication channel unselectable may be performed by the battery control MCU 41.

[0123] In the above embodiment, the slave-side wireless IC 32 has the function of the communication quality determination unit, but the monitoring IC 31 may have the function of the communication quality determination unit. Similarly, the slave-side wireless IC 32 has the function of the reply unit, but the monitoring IC 31 may have the function of the reply unit.

[0124] In the third or fourth embodiment, the number threshold may be changed depending on the distance between the battery monitoring device 30 and the battery control device 40. The number threshold may also be changed depending on the shielding properties of the battery pack 11 and the size of the internal space of the battery pack 11. For example, when the shielding properties are high and external noise is low, the number threshold may be set small.

[0125] In the above embodiment, the slave wireless IC 32 may use any communication channel when returning response data.

[0126] In step S24 of the above embodiment, the threshold value (such as the intensity threshold value or the error rate) used to determine whether the communication quality is poor may be changed. For example, the threshold value may be changed depending on the vehicle state or the communication speed. The threshold value may also be changed depending on the distance between the battery monitoring device 30 and the battery control device 40. The threshold value may also be changed depending on the shielding properties or size of the battery pack 11.

[0127] In the above embodiment, the connection establishment process (step S10) may be executed when the battery pack 11 is receiving power from an external charging device outside the vehicle. In this case, the external charging device and the battery monitoring device 30 may execute the connection establishment process instead of the battery control device 40, and data communication may be performed between the external charging device and the battery monitoring device 30. In other words, the external charging device may acquire and monitor battery information of the battery cells 22 instead of the battery control device 40.

[0128] In the above embodiment, the distance between the battery monitoring device 30 and the battery control device 40 is the communication distance between the base station side wireless antenna 43 and the slave station side wireless antenna 33. If there is no obstacle between the base station side wireless antenna 43 and the slave station side wireless antenna 33, the communication distance is the distance between the base station side wireless antenna 43 and the slave station side wireless antenna 33 in a straight line, as shown in Fig. 3. On the other hand, if there is an obstacle between the base station side wireless antenna 43 and the slave station side wireless antenna 33, the communication distance is the shortest distance along the wireless communication path along which radio waves travel, taking reflected waves into consideration.

[0129] In the above embodiment, even if the status of any communication channel becomes unavailable, the status may be reset at a predetermined timing, for example, when the ignition switch is turned off. The status may also be reset (initialized) when the vehicle state or communication speed changes. Furthermore, if a predetermined number or more of communication channels become unavailable, some or all of the channels may be reset.

[0130] In the above embodiment, if the status of any communication channel becomes unavailable (unselectable), communication channels in adjacent frequency bands may also be made unavailable because the communication quality of those channels is likely to be poor. For example, if communication channel ch23 becomes unavailable, communication channels ch22 and ch24 may also be made unavailable.

[0131] In the third embodiment, the parent-side wireless IC 42 determines that an abnormality has occurred if it is unable to receive monitoring data (control results) from the battery monitoring device 30 a predetermined number of times in succession. However, it may also determine that an abnormality has occurred if it is unable to receive monitoring data from the battery monitoring device 30 a predetermined number of times within a certain period of time.

[0132] In the above fourth embodiment, the parent-side wireless IC 42 determines that an abnormality has occurred if it is unable to receive monitoring data (control results) from a specific battery monitoring device 30 a predetermined number of times in succession. However, it may also determine that an abnormality has occurred if it is unable to receive monitoring data from a specific battery monitoring device 30 a predetermined number of times within a certain period of time.

[0133] The controller and methods described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the controller and methods described herein may be implemented by a special-purpose computer configured with a processor configured with one or more dedicated hardware logic circuits. Alternatively, the controller and methods described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0134] The following describes characteristic configurations extracted from the above-described embodiments.

[0135] [Configuration 1] A battery monitoring system (100) that monitors a battery unit (20, 21, 22), comprising: a transmitter (40) that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels; and a receiver (30) that performs various controls in accordance with the control information and returns the control results, wherein the receiver comprises: a control unit (31) that performs control in accordance with the control information; a communication quality determination unit (32) that determines the communication quality of the communication channel used for transmission when the control information is received; and a return unit (32) that returns the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good, and the transmitter comprises: an evaluation unit (42) that evaluates the communication quality of the communication channel selected when transmitting the control information to be poor if the control result is not returned from the receiver after transmitting the control information.

[0136] [Configuration 2] The battery monitoring system according to Configuration 1, wherein the number of times that the evaluation unit has evaluated the communication quality as poor is accumulated for each of the communication channels, and the transmitter makes the communication channel unselectable when the number of times is equal to or greater than a predetermined threshold.

[0137] [Configuration 3] The battery monitoring system according to Configuration 2, wherein the transmitter includes a threshold setting unit that changes the threshold depending on a vehicle state or a communication speed.

[0138] [Configuration 4] The battery monitoring system according to Configuration 3 or 4, wherein the threshold setting unit changes the threshold when the vehicle speed is equal to or greater than a predetermined speed, or when the vehicle is in an environment with a lot of external noise.

[0139] [Configuration 5] A battery monitoring system according to any one of configurations 1 to 4, wherein the communication channels include a communication channel for establishing a connection used to establish a wireless communication connection and a communication channel for exchanging battery information used to exchange battery information, the transmitter selects the communication channel for exchanging battery information when transmitting the control information, and the evaluation unit evaluates the communication channel when the communication channel for exchanging battery information is used.

[0140] [Configuration 6] The battery monitoring system according to any one of configurations 1 to 5, wherein the receiver returns the control result using the communication channel that was used when the transmitter transmitted the control information.

[0141] [Configuration 7] A battery monitoring system according to any one of configurations 1 to 6, wherein the transmitter is a battery control device that transmits control data requesting acquisition and transmission of battery information of the battery unit as the control information, and the receiver is a battery monitoring device that acquires battery information of the battery unit based on the received control data and replies with the acquired battery information as the control result.

[0142] [Configuration 8] The battery monitoring system according to Configuration 7, wherein a plurality of the battery monitoring devices are provided, and the battery control device includes an abnormality determination unit that determines that an abnormality has occurred in a specific battery monitoring device when the battery control device fails to receive the control result from the specific battery monitoring device among the plurality of battery monitoring devices a predetermined number of times in succession.

[0143] [Configuration 9] The battery monitoring system described in Configuration 7 or 8, wherein a plurality of the battery monitoring devices are provided, and the battery control device includes an abnormality determination unit that determines that an abnormality has occurred in the battery monitoring system or the battery control device when the battery control device fails to receive the control result from the battery monitoring device a predetermined number of times in succession.

[0144] [Configuration 10] A battery monitoring system (100) that monitors a battery unit (20, 21, 22) includes a transmitter (40) that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels, and a receiver (30) that performs various controls in accordance with the control information and returns the control results, wherein the transmitter includes an evaluation unit (42) that evaluates that the communication quality of the communication channel selected when transmitting the control information is poor if the control result is not returned from the receiver after transmitting the control information, and the receiver of the battery monitoring system includes: a control unit (31) that performs control in accordance with the control information; a communication quality determination unit (32) that determines the communication quality of the communication channel used for transmission when receiving the control information; and a reply unit (32) that replies with the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good.

[0145] [Configuration 11] A battery monitoring system (100) for monitoring a battery unit (20, 21, 22), comprising: a transmitter (40) that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels; and a receiver (30) that performs various controls in accordance with the control information and returns the control results, wherein the receiver comprises: a control unit (31) that performs control in accordance with the control information; a communication quality determination unit (32) that determines the communication quality of the communication channel used for transmission when the control information is received; and a return unit (32) that returns the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but does not return the control result if the communication quality determined by the communication quality determination unit is not good; and the transmitter of the battery monitoring system comprises: an evaluation unit (42) that evaluates the communication quality of the communication channel selected when transmitting the control information to be poor if the control result is not returned from the receiver after transmitting the control information.

[0146] [Configuration 12] A battery monitoring system (100) for monitoring a battery unit (20, 21, 22), comprising a transmitter (40) that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels, and a receiver (30) that performs various controls in accordance with the control information and returns the control results, the wireless communication program being executed by the transmitter and receiver of the battery monitoring system, the wireless communication program causing the receiver to perform: a control process that performs control in accordance with the control information; a communication quality determination process that determines the communication quality of the communication channel used for transmission when the control information is received; and a return process that returns the control result of the control process if the communication quality determined by the communication quality determination process is good, but does not return the control result if the communication quality determined by the communication quality determination process is not good; and the wireless communication program causing the transmitter to perform an evaluation process that evaluates the communication quality of the communication channel selected when transmitting the control information as poor if the control result is not returned from the receiver after transmitting the control information.

[0147] [Configuration 13] A battery monitoring system (100) that monitors a battery unit (20, 21, 22), the battery monitoring system including a transmitter (40) that transmits control information by wireless communication using a communication channel selected from a plurality of communication channels, and a receiver (30) that performs various controls in accordance with the control information and returns the control results, in a wireless communication method implemented by the transmitter and receiver, wherein the receiver performs: a control process that performs control in accordance with the control information; a communication quality determination process that determines the communication quality of the communication channel used for transmission when receiving the control information; and a return process that returns the control result of the control process if the communication quality determined by the communication quality determination process is good, but does not return the control result if the communication quality determined by the communication quality determination process is not good; and the wireless communication method wherein the transmitter performs an evaluation process that evaluates the communication quality of the communication channel selected when transmitting the control information as poor if the control result is not returned from the receiver after transmitting the control information.

[0148] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A battery monitoring system (100) for monitoring a battery unit (20, 21, 22), comprising: a transmitter (40) for transmitting control information by wireless communication using a communication channel selected from among a plurality of communication channels; and a receiver (30) for performing various controls in accordance with the control information and returning the control results, wherein the receiver comprises: a control unit (31) for performing control in accordance with the control information; a communication quality determination unit (32) for determining the communication quality of the communication channel used for transmission when the control information is received; and a return unit (32) for returning the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but not returning the control result if the communication quality determined by the communication quality determination unit is not good, and wherein the transmitter comprises an evaluation unit (42) for evaluating that the communication quality of the communication channel selected when transmitting the control information is poor if the control result is not returned from the receiver after the control information is transmitted.

2. The battery monitoring system of claim 1, wherein the number of times that the communication quality is evaluated as poor by the evaluation unit is accumulated for each communication channel, and the transmitter makes the communication channel unselectable if the number of times is equal to or exceeds a predetermined threshold.

3. A battery monitoring system as described in claim 2, wherein the transmitter is provided with a threshold setting unit that changes the threshold depending on a vehicle state or a communication speed.

4. A battery monitoring system as described in claim 3, wherein the threshold setting unit changes the threshold when the vehicle speed is equal to or greater than a predetermined speed, or when the vehicle is in an environment with a lot of external noise.

5. A battery monitoring system as claimed in any one of claims 1 to 4, wherein the communication channels include a communication channel for establishing a connection used to establish a wireless communication connection, and a communication channel for transmitting and receiving battery information used for transmitting and receiving battery information, the transmitter selects the communication channel for transmitting and receiving battery information when transmitting the control information, and the evaluation unit evaluates the communication channel when the communication channel for transmitting and receiving battery information is used.

6. A battery monitoring system as claimed in any one of claims 1 to 4, wherein the receiver returns the control result using the communication channel used when the transmitter transmitted the control information.

7. A battery monitoring system as claimed in any one of claims 1 to 4, wherein the transmitter is a battery control device that transmits control data requesting acquisition and transmission of battery information of the battery unit as the control information, and the receiver is a battery monitoring device that acquires battery information of the battery unit based on the received control data and replies with the acquired battery information as the control result.

8. The battery monitoring system of claim 7, wherein a plurality of the battery monitoring devices are provided, and the battery control device is provided with an abnormality determination unit that determines that an abnormality has occurred in a particular battery monitoring device among the plurality of battery monitoring devices if the control result cannot be received from the particular battery monitoring device a predetermined number of times in succession.

9. The battery monitoring system of claim 7, wherein a plurality of the battery monitoring devices are provided, and the battery control device is provided with an abnormality determination unit that determines that an abnormality has occurred in the battery monitoring system or the battery control device if the battery control device fails to receive the control result from the battery monitoring device a predetermined number of times in succession.

10. A battery monitoring system (100) for monitoring a battery unit (20, 21, 22), comprising: a transmitter (40) for transmitting control information by wireless communication using a communication channel selected from among a plurality of communication channels; and a receiver (30) for performing various controls in accordance with the control information and returning the control results, wherein the transmitter comprises an evaluation unit (42) for evaluating that the communication quality of the communication channel selected when transmitting the control information is poor if the control result is not returned from the receiver after transmission of the control information; a control unit (31) for performing control in accordance with the control information; a communication quality determination unit (32) for determining the communication quality of the communication channel used for transmission when receiving the control information; and a reply unit (32) for returning the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but not returning the control result if the communication quality determined by the communication quality determination unit is not good.

11. A battery monitoring system (100) for monitoring a battery unit (20, 21, 22), comprising: a transmitter (40) for transmitting control information by wireless communication using a communication channel selected from among a plurality of communication channels; and a receiver (30) for performing various controls in accordance with the control information and returning the control results, wherein the receiver comprises: a control unit (31) for performing control in accordance with the control information; a communication quality determination unit (32) for determining the communication quality of the communication channel used for transmission when the control information is received; and a reply unit (32) for returning the control result by the control unit if the communication quality determined by the communication quality determination unit is good, but not returning the control result if the communication quality determined by the communication quality determination unit is not good; and the transmitter of the battery monitoring system further comprises an evaluation unit (42) for evaluating that the communication quality of the communication channel selected when transmitting the control information is poor if the control result is not returned from the receiver after the control information is transmitted.

12. A wireless communication program executed by the transmitter and receiver of a battery monitoring system (100) that monitors a battery unit (20, 21, 22), the battery monitoring system including a transmitter (40) that transmits control information via wireless communication using a communication channel selected from among a plurality of communication channels, and a receiver (30) that performs various controls in accordance with the control information and returns the control results, the wireless communication program causing the receiver to perform a control process that performs control in accordance with the control information, a communication quality determination process that determines the communication quality of the communication channel used for transmission when the control information is received, and a return process that returns the control result of the control process if the communication quality determined by the communication quality determination process is good, but does not return the control result if the communication quality determined by the communication quality determination process is not good, and causing the transmitter to perform an evaluation process that evaluates the communication quality of the communication channel selected when transmitting the control information as poor if the control result is not returned from the receiver after transmitting the control information.

13. A wireless communication method implemented by the transmitter and receiver of a battery monitoring system (100) that monitors a battery unit (20, 21, 22), the battery monitoring system including a transmitter (40) that transmits control information by wireless communication using a communication channel selected from among a plurality of communication channels, and a receiver (30) that performs various controls in accordance with the control information and returns the control results, wherein the receiver performs a control process that performs control in accordance with the control information, a communication quality determination process that determines the communication quality of the communication channel used for transmission when receiving the control information, and a return process that returns the control result of the control process if the communication quality determined by the communication quality determination process is good, but does not return the control result if the communication quality determined by the communication quality determination process is not good, and the wireless communication method wherein the transmitter performs an evaluation process that evaluates the communication quality of the communication channel selected when transmitting the control information as poor if the control result is not returned from the receiver after transmitting the control information.

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