Patent Publication Number: US-2022236330-A1

Title: Battery monitoring apparatus

Description:
CROSS REFERENCE TO RELATED DOCUMENTS 
     The present application is a continuation of U.S. patent application Ser. No. 16/674,074, filed Nov. 5, 2019, which claims the benefit of priority of Japanese Patent Application No. 2018-208341 filed on Nov. 5, 2018, the entire disclosures of each of which are herein incorporated by reference. 
    
    
     BACKGROUND 
     1 Technical Field 
     This disclosure relates generally to a battery monitoring apparatus working to monitor the state of a battery cell mounted in a vehicle such as an automobile. 
     2 Background Art 
     Typical battery monitors are equipped with a battery ECU, a satellite device working to determine voltage at a battery cell in response to a command from the battery ECU, and a communication device establishing communications with the battery ECU and the satellite device. A battery monitor is known which is equipped with a wireless module working as a communication device. The battery monitor is thought of as being designed, like a wire communication device, to actuate the wireless module to start a wireless connection simultaneously with turning on of a start switch of a power unit for a vehicle, such as an engine or an electrical motor in order to eliminate dark current consumed by the communication device. 
     The wireless connection usually requires several seconds between the start and completion thereof. During all that time, it is impossible to measure the voltage at the battery cell to calculate a SOC (State Of Charge) of the battery cell. It is, therefore, impossible to start monitoring the state of the battery cell immediately after the start switch for the drive power source mounted in the vehicle is turned on, thus undesirably consuming time to start the vehicle. 
     SUMMARY 
     It is an object of this disclosure to provide a battery monitoring apparatus capable of quickly starting to monitor a state of a battery cell. 
     According to one aspect of this disclosure, there is provided a battery monitoring apparatus which monitors states of battery cells installed in a vehicle. The battery monitoring apparatus comprises: (a) a battery ECU; (b) satellite devices each of which measures a voltage at a battery cell in response to a command signal wirelessly outputted from the battery ECU; and (c) a wireless module which achieves a wireless communication between the battery ECU and each of the satellite devices after a wireless connection between the battery ECU and each of the satellite devices is completed. When receiving a start signal outputted before a start switch for a drive power source of the vehicle is turned on, the wireless module is activated to start the wireless connection between the battery ECU and each of the satellite devices. 
     The battery monitoring apparatus is capable of actuating the wireless module in response to the start signal to achieve the wireless connections before the start switch of the drive power source is turned on. This achieves the start and completion of the wireless communication earlier than when the wireless module is actuated simultaneously with turning on of the start switch of the drive power source, thereby quickly starting to monitor the state of the battery cells. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be understood more fully from the detailed description given hereinbelow and from the accompanying drawings of the preferred embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments but are for the purpose of explanation and understanding only. 
       In the drawings: 
         FIG. 1  is a schematic view which illustrates a battery monitoring apparatus according to the first embodiment; 
         FIG. 2  is a flowchart which demonstrates how a wireless module achieves wireless connections; 
         FIG. 3  is a timing chart which demonstrates a sequence of steps to achieve wireless connections; 
         FIG. 4  is a timing chart which demonstrates a sequence of steps to achieve wireless connections in a modified form; 
         FIG. 5  is a schematic view which illustrates a battery monitoring apparatus according to the second embodiment; 
         FIG. 6  is a schematic view which illustrates a battery monitoring apparatus according to the third embodiment; 
         FIG. 7  is a schematic view which illustrates a battery monitoring apparatus according to the fourth embodiment; and 
         FIG. 8  is a schematic view which illustrates a battery monitoring apparatus according to the fifth embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       FIG. 1  schematically illustrates the structure of the battery monitoring apparatus  95   a  according to the first embodiment. The battery monitoring apparatus  95   a  works to monitor the state of the assembled battery  90  made up of a plurality of battery modules  91  connected in series with each other. Each of the battery modules  91  includes a plurality of battery units  92  connected in series with each other. Each of the battery units  92  may be implemented by a single electrochemical cell or a plurality of electrochemical cells connected in series with each other. The assembled battery  90  and the battery monitoring apparatus  95   a  are mounted in a vehicle, such as an automobile, equipped with a drive power source, such as an internal combustion engine and/or an electrical motor. 
     The battery monitoring apparatus  95   a  includes the battery ECU (Electronic Control Unit)  40 , the satellite devices (e.g., satellite ECUs)  20 , one provided for each of the battery modules  91 , and the wireless module  30  which performs wireless telecommunications between the battery ECU  40  and each of the satellite devices  20 . The vehicle is equipped with the keyless entry system  10 . The keyless entry system  10  includes the controller  13  and the lock/unlock deice  18 . The controller  13  is equipped with the lock button  14  and the unlock button  15 . When the lock button  14  is depressed, the controller  13  wirelessly outputs a lock signal. Alternatively, when the unlock button  15  is depressed, the controller  15  wirelessly outputs an unlock signal. The lock/unlock device  18  locks or unlocks doors of the vehicle in response to the lock signal or the unlock signal. 
     The wireless module  30  includes the slave units  32  installed in the satellite devices  20  and the master unit  34  installed in the battery ECU  40 . The slave unit  32  may be arranged inside or outside the main body of the satellite device  20 . The master unit  34  may be disposed inside or outside the main body of the battery ECU  40 . 
     Each of the satellite devices  20  is equipped with the power supply  21  and the monitor IC  23 . The power supply  21  is connected to the battery module  91  and the monitor IC  23  and also connected to the slave unit  32  through the insulating device  27 . The power supply  21  delivers electrical power, as derived from the battery module  91 , to the monitor IC  23  and the slave unit  32  to actuate the monitor IC  23  and the slave units  32 . 
     The monitor IC  23  is, as clearly illustrated in  FIG. 1 , electrically connected to terminals of each of the battery units  92  and also connected to the slave unit  32  through the insulating device  27 . The insulating device  27  creates electrical insulation between the slave unit  32  which is designed in the form of a low voltage circuit and each of the power supply  21  and the monitor IC  23  which are designed in the form of a high voltage circuit and also achieves transmission of electrical power or electrical signals therebetween. 
     The battery ECU  40  is equipped with the power supply  47  and the microcomputer  43 . The power supply  47  is connected to the battery  98 , the microcomputer  43 , and the master unit  34  and delivers electrical power, as derived from the battery  98 , to the microcomputer  43  and the master unit  34  to actuate the microcomputer  43  and the master unit  34 . The battery  98  is separate from the battery modules  91 . 
     The microcomputer  43  outputs commands to the master unit  34  for the satellite devices  20 . The master unit  34  wirelessly outputs the commands to the slave units  32 . When receiving the command, each of the slave units  32  outputs it to the monitor IC  23 . The monitor IC  23  is responsive to the command to measure a terminal-to-terminal voltage at each of the battery units  92 , electrical current in each of the battery units  92 , and/or temperature of each of the battery units  92 , or conduct self-diagnosis and outputs data on the terminal-to-terminal voltage, the current, the temperature, and a result of the self-diagnosis to the slave unit  32 . The slave unit  32  then wirelessly outputs the received data to the master unit  34 . 
     When receiving the data from the slave units  32 , the master unit  34  transmits it to the microcomputer  43 . The microcomputer  43  analyzes the data and calculates an internal resistance and a state of charge (SOC) in each of the battery units  92  to monitor the state of the assembled battery  90 . 
     The unlock signal outputted by the controller  13  of the keyless entry system  10  also functions as a start signal to turn on or actuate the slave units  32  and the master unit  34 . Specifically, when the drive power source installed in the vehicle is at rest, the slave units  32  and the master unit  34  are all in an off-state, but placed in a stand-by state where the unlock signal is receivable. When receiving the unlock signal, each of the slave units  32  and the master unit  34  is actuated to start telecommunications with the other. 
       FIG. 2  is a flowchart of a sequence of steps from output of the unlock signal to completion of wireless connection.  FIG. 3  is a timing chart which demonstrates the sequence of steps in  FIG. 2 . 
     When a driver of the vehicle presses the unlock button  15  of the controller  13 , the controller  13  outputs the unlock signal in step S 101 . When receiving the unlock signal outputted from the controller  13  in step S 101 , the master unit  34  starts to be actuated in step S 103 . When receiving the unlock signal in step S 104 , the slave units  32  starts to be activated in step S 105 . Afterwards, the master unit  34  and the slave units  32  start wireless communications in step S 106  and complete the wireless communications in step S 107 . The completion of the wireless communications means a condition where it is possible to transmit a signal between the master unit  34  and the slave units  32 . Subsequently, the master unit  34  and the slave units  32  are placed in the standby mode. 
     Afterwards, the microcomputer  43  determines whether the start switch  110 , as illustrated in  FIG. 1 , for the drive power source has been turned on or not in step S 108 . This determination may be made by another device, i.e., the ECU  200  installed in the vehicle other than the battery ECU  40 . The start switch  110  is connected to the battery  100 . The switch  110  is turned on in response to turning on of an ignition switch of the vehicle. The microcomputer  43  determines that the start switch  110  is turned on when the ignition switch is turned on. Alternatively, the ECU  200  may determine that the start switch  110  has been turned on, that is, that the drive power source has been actuated in response to turning on of the ignition switch and output a signal indicative thereof to the microcomputer  43 . If a NO answer is obtained in step S 108 , such a determination is repeated. Alternatively, if a YES answer is obtained in step S 108  meaning that the start switch has been turned on, the determining device outputs a given signal to each of the monitor ICs  23  with or without wire to turn on the monitor IC  23 . When activated, the monitor IC  23  measures the terminal-to-terminal voltage at the battery units  92 , the electrical current in the battery units  92 , and/or the temperature of the battery units  92  or performs the self-diagnosis, and then outputs data on them to the slave unit  32 . The slave unit  32  wirelessly outputs the received data to the master unit  34 , in other words, starts the wireless communication between itself and the mater unit  34  in step S 109 . This starts the communication between the monitor IC  23  and the microcomputer  43 . Specifically, the microcomputer  43  outputs a command to the monitor ICs  23 . The monitor ICs  23  output the voltage data, etc. to the microcomputer  43 . 
     Step S 108 , as described above, determines whether the start switch of the drive power source is turned on, however, it may alternatively determine, as illustrated in  FIG. 4 , whether the driver has sat on the seat in the vehicle. If the driver is determined to have sat on the seat, the above wireless communications are started. 
     This embodiment offers the following beneficial advantages. 
     The wireless communication in the battery monitoring apparatus  95   a  enables space required for installation of wire harnesses to be reduced. The battery monitoring apparatus  95   a  is capable of actuating the wireless module  30  in response to the unlock signal from the keyless entry system  10  to achieve the wireless connections before the start switch of the drive power source is turned on. This achieves the start and completion of the wireless communication earlier than when the wireless module  30  is actuated simultaneously with turning on of the start switch of the drive power source, thereby quickly starting to monitor the state of the assembled battery  90  and enabling the vehicle to be started promptly. 
     The start signal to actuate the wireless module  30  is, as described above, provided by the unlock signal generated by the keyless entry system  10 . This enables the wireless module  30  to be turned on in response to the unlock signal early before the driver gets in the vehicle to start the wireless communications. This results in an increase in time interval between the start of the wireless connections and the turning on of the start switch of the drive power source, thereby ensuring the stability in completing the wireless connections until the start switch of the drive power source is turned on. This quickly starts monitoring the conditions of the assembled battery  90  after the start switch of the drive power source is turned on. 
     Additionally, the master unit  34  and the slave units  32  are both turned on in response to the unlock signal, thereby quickly starting the wireless connections. 
     Embodiments other than the first embodiment will be described below. In the following discussion, the same reference numbers as in the first embodiment will refer to the same or similar parts, and explanation thereof in detail will be omitted here. 
     Second Embodiment 
     The battery monitoring apparatus  95   b  of the second embodiment will be described below with reference to  FIG. 5 .  FIG. 5  illustrates only one satellite device  20  for the sake of simplicity of disclosure. The same is true for the third or following embodiments described later. 
     The master unit  34  and the slave unit  32  are each designed not to receive the unlock signal. When the drive power source in the vehicle is in the off-state, the master unit  34  is at rest and not placed in the stand-by mode in which the a wireless signal is receivable. When the drive power source in the vehicle is in the off-state, the slave unit  32  is not yet actuated, but placed in the stand-by mode in which a wireless signal outputted from the master unit  34  is receivable. 
     The battery ECU  40  of the battery monitoring apparatus  95   b  is equipped with the switch  41  disposed in a conductor which achieves an electrical connection between the power supply  47  and the master unit  34 . When receiving the unlock signal from the controller  13 , the lock/unlock device  18  unlocks the doors of the vehicle and outputs a given signal to the microcomputer  43  through the CAN  42 . When receiving such a signal, the microcomputer  43  turns on the switch  41  to actuate the master unit  34 . The master unit  34  then wirelessly outputs a signal to the slave unit  32  to actuate the slave unit  32 . 
     The second embodiment offers the following beneficial advantages. 
     The microcomputer  43  is designed to turn on the switch  41  to start the master unit  34 . This enables the master unit  34  to be turned on without need for placing the master unit  34  in the stand-by mode in which the unlock signal is receivable. This eliminates the need for consumption of dark current. 
     The turning on of the salve unit  32  is achieved by wirelessly outputting a signal from the master unit  34  to the slave unit  32 . The slave unit  32  only needs to be designed to receive a wireless signal from the master unit  34 , in other words, does not need to have a structure capable of receiving the unlock signal. This results in simple functions and structure of the slave unit  32 . 
     Third Embodiment 
     The battery monitoring apparatus  95   c  in the third embodiment will be described below with reference to  FIG. 6 . The slave unit  32  is, like in the second embodiment designed not to have a structure to receive the unlock signal. The master unit  34  is first actuated in response to the unlock signal and then wirelessly outputs a signal to the slave unit  32  to turn on the slave unit  32 . 
     The above structure of the battery monitoring apparatus  95   c  in which the master unit  34  receives the unlock signal, like the second embodiment, results in simplified functions and structure of the slave unit  32 . 
     Fourth Embodiment 
     The battery monitoring apparatus  95   d  in the fourth embodiment will be described below with reference to  FIG. 7 . The master unit  34  is designed not to receive the unlock signal. The slave unit  32  is actuated first in response to the unlock signal and then wirelessly outputs a signal to the master unit  34  to turn on the master unit  34 . 
     The above structure of the battery monitoring apparatus  95   d  in which the master unit  34  is actuated in response to a wireless signal outputted from the slave unit  32  enables the master unit  34  to be designed only to receive the wireless signal from the slave unit  32 , thereby eliminating the need for the master unit  34  to be engineered to receive the unlock signal. This results in simplified functions and structure of the master unit  34 . 
     Fifth Embodiment 
     The battery monitoring apparatus  95   e  in the fifth embodiment will be described below with reference to  FIG. 8 . The battery monitoring apparatus  95   e  includes a plurality of master units  34 . Each of the master units  34  is associated with one or more of the slave units  32 . In other words, each of the master units  34  wirelessly outputs a signal to corresponding one or more of the slave units  32 . The slave unit  32  is turned on in response to the wireless signal outputted from a corresponding one of the master units  34  to start a wireless connection therebetween. 
     As apparent from the above discussion, each of the master units  34  is designed only to wirelessly output a signal to corresponding one or more of the slave units  32 , thereby eliminating a load on the master units  34  to directly turn on the slave units. Each of the master units  34  achieves a wireless connection with the corresponding one or more of the slave units  32 , thereby resulting in a decrease in load on the master units  34  required to establish connections with the slave units  32  as compared with the conventional structure. 
     Modifications 
     Each of the above embodiments may be modified in the following ways. For instance, a wireless or a wired signal may be used to turn on the wireless module  30  instead of the unlock signal. 
     Specifically, for example, when the door of the vehicle is opened, a wired or wireless start signal may be outputted to the master unit  34 , the slave units  32 , the microcomputer  43 , or the monitor ICs  23  to turn on the wireless module  30 . Alternatively, a human detecting sensor may be used. When a human body is detected by the human detecting sensor, a wired or wireless start signal may be outputted to the master unit  34 , the slave units  32 , the microcomputer  43 , or the monitor ICs  23  to turn on the wireless module  30 . Alternatively, when the driver sits on the seat in the vehicle, a wired or wireless start signal may be outputted to the master unit  34 , the slave units  32 , the microcomputer  43 , or the monitor ICs  23  to turn on the wireless module  30 . 
     The battery monitoring apparatus  95   b  in the second embodiment of  FIG. 5  which has the switch  41  to establish or block an electrical connection between the power supply  47  and the master unit  34  in the battery ECU  40  may alternatively be designed to have a switch disposed on an conductor connecting between the power supply  21  and the slave unit  32  in the satellite device  20 . When receiving the unlock signal, the lock/unlock device  18  outputs a signal to the monitor IC  23  through a CAN. The monitor IC  23  then turns on the switch to connect between the power supply  21  and the slave unit  32  to activate the slave unit  32 . The slave unit  32  then wirelessly outputs a signal to the master unit  34  to activate the master unit  34 . 
     The battery monitoring apparatus  95   d  illustrated in  FIG. 7  may alternatively be designed to have the slave units  32  only one of which receives the unlock signal and then wirelessly outputs a signal to the master unit  34  to turn on the master unit  34 . The master unit  34  then wirelessly outputs signals to turn on the slave units  32  other than the one which has received the unlock signal. 
     The battery monitoring apparatus  95   e  in the fifth embodiment of  FIG. 8  may alternatively be designed not to determine which of the slave units  32  each of the master units  34  should be associated with in an initial stage, but determine only the number of the slave units  32  that each of the master units  34  should communicate with in the initial stage. After outputting a wireless signal, each of the master units  34  selects those slave units  32  which have received the wireless signal as target(s) which it should have a wireless connection with. Alternatively, when receiving a wireless signal from one of the slave units  32 , the master unit  34  selects the slave unit  32  which outputted the wireless signal as a target which it should have a wireless connection with. 
     While the present invention has been disclosed in terms of the preferred embodiments in order to facilitate better understanding thereof, it should be appreciated that the invention can be embodied in various ways without departing from the principle of the invention. Therefore, the invention should be understood to include all possible embodiments and modifications to the shown embodiments which can be embodied without departing from the principle of the invention as set forth in the appended claims.