JP2009185764A - Battery monitoring device and battery monitoring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery monitoring device enabling to determine battery replacing timing, by notifying a possible neglected period of a battery until upcoming start, when an ignition switch is turned off. <P>SOLUTION: This device monitors the state of the battery charged by an alternator by starting an engine to supply electric power to a starter motor. The battery monitoring device, when the ignition switch is turned off, detects a charging quantity of the battery, and estimates dark electric power consumed while the ignition switch is turned off and cranking time required electric power required for upcoming start of the engine, and calculates and notifies a possible neglected period of the battery enabling upcoming start based on these numeric values. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a battery monitoring apparatus and a battery monitoring method, and more particularly, to a battery monitoring apparatus and a battery monitoring method that can predict battery power up according to the battery state during cranking and prompt battery replacement.

  In recent years, along with electronic control of vehicles, there is a tendency to electronically control vehicle equipment using battery power in response to a user's demand for comfort on the vehicle. For example, electric curtains, multi-speaker surround devices, and the like have been newly electronically controlled, starting with the conventional motorization of seat position adjustment and the motorization of sliding door opening and closing.

  On the other hand, in-vehicle devices that are electronically controlled for the pursuit of comfort are controlled using in-vehicle batteries, so that batteries that supply power to these electrical components play an important role in the vehicle. It has become to. In-vehicle batteries are mainly lead-acid batteries, and the electric power supplied to the electrical components is charged by an alternator that generates electricity by the rotation of the engine of the vehicle.

  In this way, the on-board battery repeatedly charges and discharges, but some electronic control devices consume battery power even when the engine is stopped, and a minute current called dark current flows even when the engine is stopped. As a result, the battery capacity gradually decreases, and there is a possibility that the engine cannot be restarted if the engine is stopped for a long time.

  For this reason, when the power consumption calculated in the engine stop state exceeds a predetermined threshold value, a vehicle battery that notifies the fact by the notification means or prohibits the supply of power to the predetermined electrical component Japanese Patent Application Laid-Open No. H10-228707 describes a power consumption monitoring apparatus. It also detects the battery voltage and discharge current when the engine is started, calculates the remaining charge after the engine is stopped, and determines that the next engine start is impossible from the remaining battery charge. Patent Document 2 discloses a vehicle-mounted battery diagnosis / alarm device that emits.

JP 2004-196060 A JP-A 63-298078

  However, there is no conventional battery monitoring device that tells the occupant time information that allows the vehicle to be left in the engine stopped state in consideration of the power required for starting the engine next time when the engine is stopped. .

  Therefore, the present invention can leave the vehicle in the engine stopped state by obtaining time information in which the vehicle can be left in the engine stopped state from the power consumption at the start in consideration of engine friction when the engine is stopped. It is an object of the present invention to provide a battery monitoring device and a battery monitoring method that can transmit time information to the occupant, know the battery consumption state and replacement time, and are less likely to cause engine start failure at the start. This engine friction is obtained from engine inherent parameters such as oil viscosity, cylinder and piston wear, etc., but it is difficult to measure this inherent parameter. Guess using the method.

  The battery monitoring device of the present invention that achieves the above object is a device for monitoring the state of a battery provided in a vehicle that supplies electric power to a starter motor to start an engine, and when the ignition switch is turned off, Based on the amount of charge, the dark power consumed when the ignition is turned off, and the power required to start the engine, the battery can be left the next time it can be started, and this is notified. It is characterized by providing a means.

  The battery monitoring method of the present invention that achieves the above object is a method of monitoring the state of a battery provided in a vehicle that supplies power to a starter motor to start an engine, and when an ignition switch is turned off, The step of calculating the amount of charge of the battery, the dark power consumed when the ignition is turned off, and the power required for starting the engine, and the calculated amount of battery charge, dark power, and power required for starting the engine And a step of calculating a time for which the battery can be left for the next start, and a step of notifying the calculated time for which the battery can be left to the outside through a display or a sound device. Is the method.

  According to the battery monitoring device and the battery monitoring method of the present invention, when the driver turns off the ignition switch to stop the engine, the battery stand-by time that can reliably start the engine at the next engine cranking is notified. Therefore, when this battery leaving time is short, it can be determined that the battery has deteriorated, and the battery replacement time can be known, so that it is possible to prevent engine start failure due to battery exhaustion. .

  Hereinafter, embodiments of the present invention will be described in detail based on specific examples with reference to the accompanying drawings.

  FIG. 1 shows a configuration of an embodiment of a battery monitoring apparatus of the present invention for monitoring a battery mounted on a vehicle in order to drive an engine of a vehicle such as an automobile. The battery 1 of this embodiment is a lead storage battery, and a starter motor 3 that cranks and starts the engine 1 and an alternator (ALT) 4 that charges the battery 1 are connected to the positive power terminal of the battery 1. Yes. Near the positive power supply terminal of the battery 1, a voltage sensor 1 </ b> V that detects the battery voltage and a current sensor 1 </ b> A that detects the amount of current flowing out from or flowing into the battery 1 are provided. Further, the container of the battery 1 is provided with a temperature sensor 1T such as a thermistor for detecting the liquid temperature of the battery 1.

  The vehicle is in an on state regardless of the position of an ignition switch (hereinafter referred to as IG switch) 5, the first electrical component 11 that always consumes the power of the battery 1, and the IG switch 5 is connected to the ignition position IG and the accessory position ACC. And the second electrical component 12 that is turned on at this time and consumes power at this time. The first electrical component 11 includes a clock, an automatic door lock or keyless entry, an anti-theft device, and the like, and a minute current called dark current flows through these even when the engine is stopped.

  Further, in this embodiment, a control device 10 for starting the engine 1, controlling charging, and monitoring the state of the battery 1 is provided. The control device 10 receives a starter signal when the ignition switch 5 reaches the starter position ST, and also receives signals from the current sensor 1A, the voltage sensor 1V, and the temperature sensor 1T. In the main body of the control device 10, a non-volatile memory 13 for storing input data is provided. The nonvolatile memory 13 may be provided outside the control device 10. Further, the non-volatile memory 13 may be a standby RAM.

  In this embodiment, the control device 10 is connected to a display device 6 including a speaker 7 that can output sound, such as a television or a car navigation device. Further, the communication device 8 may be connected to the control device 10 and configured to be able to communicate with the mobile phone 20. In this case, the control device 10 can transmit the state of the battery 1 and the like to the vehicle occupant. Here, operation | movement of the control apparatus 10 is demonstrated using FIGS. 2-8.

  FIG. 2A is a flowchart showing processing when the IG switch 5 is in the ON position in the control device 10 shown in FIG. This process is executed every predetermined time, for example, every several ms. Although the process when the IG switch 5 is in the on position will be described here, this process can be performed in any state as long as the IG switch 5 is not in the off position.

  In step 201, it is first determined whether or not the IG switch 5 has been changed from the on position to the off position. When the IG switch 5 is changed from the on position to the off position, the process proceeds to step 202, where control is performed when the IG switch 5 is in the off position. This control will be described in detail later.

  On the other hand, when it is determined in step 201 that the IG switch 5 has not been changed from the on position to the off position, the routine proceeds to step 203, where it is determined whether the engine is started and cranking is in progress. If the engine is cranking, the process proceeds to step 204, and control during cranking is performed. This control will be described in detail later.

  If it is determined in step 203 that the engine is not cranking, the process proceeds to step 205, and control during engine operation is performed. Since control during engine operation is not relevant to the present invention, description of control during engine operation is omitted.

  FIG. 2B is a flowchart showing processing when the IG switch 5 is turned off in the control device 10 shown in FIG. This processing is started and executed by a soak timer or the like at predetermined time intervals, for example, every 1 to 2 hours when the IG switch 5 is in the OFF position. In step 206, control while the engine is stopped is performed. This control will be described in detail later. When step 206 is completed, the process proceeds to step 207, where the control device 10 executes a control to turn off its own power supply, and this routine is ended.

  FIG. 3 is a flowchart showing details of the control during the engine stop shown in step 202 of FIG. 2, and the control device is activated and executed. While the engine is stopped, in step 301, the control device 10 takes in the voltage value from the voltage sensor 1V described in FIG. 1 and takes in the dark current from the current sensor 1A. Then, in step 302, the dark power is calculated. In step 303, the dark power is stored in the memory 13, and this routine is finished. In this embodiment, the dark power is calculated every 1 to 2 hours while the engine is stopped, added to the previous dark power value, and stored in the memory 13. Although not shown in FIG. 3, the dark power value stored in the memory 13 is cleared when the engine is started.

  FIG. 4 is a flowchart showing details of control during cranking shown in step 204 of FIG. In step 401, it is determined whether or not cranking is started. When cranking is started, the process proceeds from step 401 to step 402, the cranking start time is stored, and the process proceeds to step 403. On the other hand, if cranking is already in progress, the process proceeds directly from step 401 to step 403. In step 403, battery voltage and battery current are detected.

  FIG. 5 shows changes in battery voltage and battery current during cranking over time. When the cranking is started at time t1, the battery voltage indicated by the symbol B once greatly decreases and reaches the lowest voltage at the time of the battery voltage cranking indicated by the symbol A. The battery voltage then repeatedly rises and falls several times (the number of peaks when the battery voltage moves up and down is indicated by the symbol D), and rises after cranking ends at time t2. On the other hand, the battery current indicated by symbol E once increases greatly after the cranking is started at time t1, and reaches the maximum value of the battery current sensor value indicated by symbol F at the time of cranking. Thereafter, the battery current repeatedly decreases and increases several times, and becomes zero after the cranking is completed at time t2. The cranking time is from time t1 to time t2 indicated by the symbol C. The time stored in step 401 in FIG. 4 is time t1.

  Returning to FIG. 4, when the battery voltage and the battery current are detected in step 403, the number of voltage changes (the number of peaks D shown in FIG. 5) is calculated in step 404. In the subsequent step 405, it is determined whether or not the cranking has been completed. If it is determined that the cranking has been completed, the process proceeds to step 406, but if it is determined that the cranking has not yet been completed, the process proceeds to step 403. Returning to step 403, the processing from step 403 to step 405 is repeated.

  In step 406, which proceeds when it is determined in step 405 that cranking has been completed, cranking is determined from the cranking end time (time t2 in FIG. 4) and the start time stored in step 402 (time t1 in FIG. 4). Ranking time C is calculated. In the subsequent step 407, the required power for cranking is estimated based on the number D of peaks calculated in step 404 and the cranking time C calculated in step 406, and this routine is terminated.

  Here, estimation of the required power during cranking from time t1 to time t2 will be described with reference to FIG. The power required for cranking is the product of the current consumption and the voltage consumption during cranking. The consumption current and the consumption voltage at the time of cranking are expressed by the time integration of the instantaneous values of the battery voltage and the battery current shown in FIG. 5, and this corresponds to the portion shown by hatching in FIG. Therefore, by measuring the battery voltage and current at the time of cranking with a short sampling period, it is possible to obtain the required power at the time of cranking.

However, expensive hardware such as a high-performance A / D converter is required to obtain the required power during cranking by this method. Therefore, in this embodiment, the battery voltage B before cranking, the minimum value A of the battery voltage at the time of cranking, the battery current E before the cranking, the maximum value F of the battery current at the time of cranking, and the cranking time C Using the corresponding coefficient I and the coefficient J corresponding to the number of peaks (number of cranks up and down), the following equation:
(BA) × (FE) = Basic power consumption Required power during cranking = Basic power consumption × I × J
It is demanded using. The map of the coefficient I according to the cranking time C has characteristics as shown in FIG. 9A, and the map of the coefficient J according to the number of peaks (the number of cranks up and down) is shown in FIG. 9B. It is a characteristic that

  FIG. 6 is a flowchart showing details of the control when the IG switch is turned off shown in step 207 of FIG. In step 601, the dark power and the required power at the time of cranking are read, and in the next step 602, the estimated value of the battery charge is read. The battery charge amount (battery charge rate) is calculated based on the battery voltage and current during the period in which the control device 10 shown in FIG. 1 is in the operating state, and is stored in the memory 13 of the control device 10 each time it is calculated. It is what has been. Since the calculation method is well-known, description is abbreviate | omitted. When step 602 ends, in step 603, the battery remaining time is calculated.

  The battery leaving time in step 603 is obtained by subtracting the cranking power (kmh) from the battery charge (kmh) when the IG switch is turned off to obtain the amount of power (kwh) that can be used during parking. Sometimes it can be calculated by dividing the amount of power available (kwh) by dark power (km). In other words, the power required for the next engine start is configured to use the latest value obtained at the time of calculating the battery dischargeable time. For example, when the required power is not calculated after shipment, the value at the time of shipment is used, and when the required power is calculated, the value obtained from the data at the previous cranking is used.

  In calculating the battery leaveable time, a logic that corrects the influence of temperature and ignition off time (time between trips) from the measurement results at the time of past cranking may be used. This is because the lower the temperature, the lower the voltage that can be output from the battery, and therefore the more electric power (starting power for cranking) necessary for starting the engine. Therefore, for example, the time to start is known from the time when the IG switch is turned off and the time scheduled for parking, so it is better to correct the power required for starting based on the environmental temperature based on whether the starting time is daytime or nighttime. Because it is good.

  FIG. 7A shows the estimated battery charge value when the IG switch is turned off read in step 602 with a broken line R when the maximum charge amount of the battery is 100%. Assuming that the estimated value of power required at the time of cranking read in step 601 is P with respect to the estimated battery charge value R when the IG switch is off, the value of the estimated value P of power required at the time of cranking is It will not change until the next cranking. On the other hand, the dark power (power consumed by dark current) Q read in step 601 gradually increases as the engine stop time becomes longer and the battery leaving time becomes longer.

  In the state shown in FIG. 7A, the power value obtained by adding the dark power Q to the estimated power value P required during cranking is smaller than the estimated battery charge value R when the IG switch is off. Can be started by cranking. On the other hand, in the state shown in FIG. 7B, the battery leaving time becomes longer, and the power value obtained by adding the dark power Q to the estimated power value P required at the time of cranking is estimated as the battery charge when the IG switch is off. This indicates a state in which the value is larger than the value R. This state is a state where the battery runs out at the next cranking and cranking cannot be performed.

  The control device calculates the dark power value when the engine is stopped from the past detected value in step 304 of FIG. 3 and stores it. Therefore, when the state of the battery is the state shown in FIG. 7A, the control device in FIG. ) Can be obtained by calculation. The period from the state shown in FIG. 7A to the state shown in FIG.

  The battery leaving time calculated in step 604 is displayed on the display in step 604. The display device may be any display device capable of displaying information, such as a vehicle navigation device screen, a vehicle television screen, or a vehicle audio device screen, and is displayed on any one of these screens. At this time, it is also possible to inform the occupant of the battery leaveable time by voice at the same time.

  It should be noted that, instead of displaying the battery leaveable time, the battery state after the predetermined time when the user performs parking for a predetermined time will be displayed in a diagram as shown in FIGS. You can also

  In the subsequent step 605, it is determined whether or not the battery leaving time determined in step 603 is smaller than a specified value H. The specified value H is, for example, about one week, and is a value that prevents the battery from starting up unless the engine is started for one week. If the determination in step 605 is NO, the routine is terminated as it is. If YES, the battery is left standing for about one week, and the battery is approaching the end of its life. A display prompting the user to replace the battery is added to the display, and this routine is terminated.

  FIG. 8 is a time chart showing the operation of each part of the battery monitoring device of the present invention with time, and shows the operation and operation content of the control device described with reference to FIGS. Consider a case where the IG switch is turned on at time T1 and turned off at time T2. The engine is stopped until time T1, and is operated by being cranked for a predetermined time at time T1. Further, when the IG switch is turned off at time T2, the engine is also stopped.

  The control device operates intermittently while the engine is stopped until time T1, and measures dark power. Although the measurement of dark power is shown only once in FIG. 8, the measurement of dark power is performed every predetermined time. Therefore, if the engine stop period is long, the dark power measurement is performed a plurality of times. When the IG switch is turned on at time T1, the control device operates to determine engine friction at the end of cranking. When the IG switch is turned off at time T2, the control device determines the amount of charge of the battery, determines whether or not the next cranking is possible, and displays the battery standable time as a notification on the information panel (display).

  The above is an example of the operation of the control device of the present invention, and the control device of the present invention can also perform the following operations.

  (1) When detecting the power required for cranking, the engine friction is estimated in consideration of the engine's inherent parameters such as engine oil viscosity, cylinder and piston wear, engine component assembly accuracy, At the time of calculating the battery leaveable time, the battery leaveable time is calculated in consideration of the estimated friction.

(2) When the IG switch is off, display whether the next cranking is possible or not on the display.
(3) When the engine has been stopped for a long time and the battery has run out at the next cranking, and it is approaching a state where cranking cannot be performed, the state that the battery is running out is transmitted to the mobile phone of the vehicle user via the communication device Prompting the engine to start early or replace the battery.

(4) When dark power increases for some reason and there is a concern that the battery will run out in a short period of time, a state in which the battery is running out is transmitted to the mobile phone of the user of the vehicle via the communication device to suppress the increase in dark power. Encourage action, early engine start, or battery replacement.
(5) When the IG switch is turned off and the engine is stopped, the crank angle of the engine is detected, and when the neglectable time is calculated, the neglectable time of the battery is calculated in consideration of the crankshaft angle.

  Here, the calculation of the battery remaining time based on the detected engine crank angle described in (5) will be described in detail. A four-cycle engine has four strokes of suction, compression, expansion, and exhaust, and the most torque is required to push the piston from the bottom dead center to the top dead center in the compression stroke and the exhaust stroke. Therefore, at the start, the drive power of the starter increases when the piston is pushed up from the bottom dead center to the top dead center, and the starter drive power decreases when the piston drops from the top dead center to the bottom dead center. The power required for cranking needs to be corrected according to the shaft angle.

  On the other hand, in the case of a 4-cylinder port injection engine, the four strokes of each cylinder with respect to the crankshaft angle are as shown in FIG. 10, and the injection period is performed from the second half of the compression stroke to the second half of the expansion stroke. In each cylinder, injection is performed during the injection period, and ignition is performed at the ignition timing, whereby an explosion occurs in the cylinder and the engine is driven. Note that FIG. 10 shows only the injection period and ignition timing of the second cylinder, but the power required for cranking takes into account all cylinders (first to fourth). For example, when the crankshaft angle is in a position where the crankshaft angle exceeds 540 ° (the injection period of the second cylinder) and starting is started from this position, the second cylinder is first ignited.

  Therefore, when cranking is performed from just the right timing (crank angle), the injected fuel is immediately sucked into the cylinder and ignited (explosion), so the time required to drive the engine only with the starter motor Shortens and consumes less power. However, when cranking is performed in a state where the crank angle is deviated from this just right timing, the required power also increases as the crank angle (time) until ignition is increased.

  From this, when the IG switch is turned off and the engine stops, it is possible to leave the battery more accurately by detecting the crank angle of the engine and calculating the battery leave time based on the detected crank angle. Time can be calculated.

  In the above-described embodiment, an example of a lead battery has been described as a vehicle-mounted battery for determining replacement. However, the present invention can be applied to battery replacement determination even if the battery is a lithium ion battery or a nickel metal hydride battery. It is.

It is a block diagram which shows the structure of one Example of the battery monitoring apparatus of this invention. It is a flowchart which shows the outline | summary of the operation | movement procedure of the control apparatus shown in FIG. It is a flowchart which shows the control in the engine stop of the control apparatus of FIG. It is a flowchart which shows the control during engine cranking of the control apparatus of FIG. It is a characteristic view which shows the time change of a battery voltage and a battery current at the time of starting of the engine of the vehicle carrying the battery monitoring apparatus of this invention. It is a flowchart which shows control when the IG switch of the battery monitoring apparatus of this invention is turned off. (A) is a figure which shows the state in which the sum of the electric power required at the time of next cranking and the electric power extinguish | disappeared by dark current is less than the estimated value of the battery charge amount estimated at the time of IG switch-off, (b) It is a figure which shows the state in which the sum of the electric power required at the time of next cranking and the electric power which lose | disappears by dark current is over the estimated value of the battery charge amount estimated at the time of IG switch-off. It is a time chart which shows operation | movement of each part of the battery monitoring apparatus of this invention with time. (A) is a map diagram showing a correction coefficient for the required power during cranking according to the cranking time, and (b) shows a correction coefficient for the required power during cranking according to the number of peaks of the battery voltage during cranking. FIG. It is explanatory drawing which shows transition of the electric power required for cranking according to the crank angle in a 4-cylinder engine, the stroke of each cylinder, and a crank angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 1A Current sensor 1T Temperature sensor 1V Voltage sensor 2 Engine 3 Starter motor 4 Alternator (ALT)
5 Ignition switch (IG switch)
6 Display device 7 Speaker 8 Communication device 10 Control device 11 First electrical component 12 Second electrical component 13 Memory 20 Mobile phone

Claims (4)

A device for monitoring a state of a battery provided in a vehicle that supplies power to a starter motor to start an engine,
Based on the amount of charge of the battery when the ignition switch is turned off, the dark power consumed when the ignition is turned off, and the power required to start the engine, the time that the battery can be left for the next start is determined. A battery monitoring device comprising a neglectable time notification means for calculating and notifying of this.   The engine further includes crank angle storage means for storing the crank angle of the engine when the ignition switch is turned off and the engine is stopped. Electric power necessary for starting the engine is stored in the crank angle storage means. The battery monitoring apparatus according to claim 1, wherein the battery monitoring apparatus calculates the crank angle based on the crank angle.   The power required for starting the engine is the basic power consumption obtained based on the battery voltage and battery current measured when the engine is started, the time required for cranking, or the battery voltage at the time of cranking, or The battery monitoring device according to claim 1, wherein the battery monitoring device is obtained by performing correction according to the number of peaks of change in current. A method for monitoring a state of a battery provided in a vehicle that supplies power to a starter motor to start an engine,
Calculating the amount of charge of the battery, the dark power consumed when the ignition is turned off, and the power required for starting the engine when the ignition switch is turned off; and
Based on the calculated charge amount of the battery, dark power, and electric power necessary for starting the engine, calculating a time for which the battery can be left for the next start,
And a step of notifying the calculated battery remaining time to the outside through a display or a sound device.

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