JP5644190B2 - Battery state estimation device and battery information notification device - Google Patents

Description

  The present invention relates to a battery state estimating device and a battery information notifying device, and in particular, a battery state estimating device for estimating a battery state of an engine starting battery and a battery information notifying device for notifying battery information of the engine starting battery to a vehicle control unit. About.

  In recent years, parameters representing battery state such as internal resistance, discharge voltage, open circuit voltage, remaining capacity, state of charge (SOC), health level (SOH), and measurement parameters (battery information) for calculating battery state are widely used. It has been. In such a background, for example, as the performance of mobile objects such as automobiles and portable devices has become higher, the load on the batteries used for these has increased, and in order to fulfill various required functions The importance of battery state monitoring and battery state control is increasing.

  Engine start-up batteries installed in vehicles are expected to have technology that keeps the batteries in a battery state suitable for these applications in order to cope with idle stop start (ISS) and regenerative charging that are performed to reduce exhaust gas. It is rare. Lead batteries are one of the typical batteries applicable to these applications. In the engine starting battery, as a technique for estimating the battery state, a technique for calculating the battery state by comparing a voltage and DC internal resistance at the time of starting the engine with a data map measured in advance, or a state of charge (SOC) in real time. In order to estimate, a technique has been proposed in which a current sensor is mounted on a vehicle and SOC is corrected by current integration (see, for example, Patent Documents 1 and 2).

  When the battery state is calculated (estimated) from the battery information at the time of starting the engine, since the discharge voltage depends on the current, a map of voltage and current is generally referred to. FIG. 6 schematically shows the voltage and current waveforms of the lead battery when the engine is started. In FIG. 6, the sign of the current represents the charging current as positive and the discharging current as negative.

  As shown in FIG. 6, when the engine is started, first, an inrush current (discharge current) flows through the starter, and then when the starter operates to start the engine and the generator starts to operate, a charging current flows. In order to estimate the battery state from the voltage and current of the engine starting battery, the voltage and battery data measured within a short time after the start of energization are used in order to avoid the influence of the concentration polarization of the engine starting battery due to past charging and discharging. It is preferable. Further, when measuring the current, it is preferable to measure in a state where a certain amount of current flows in order to eliminate the influence of dark current and the like. For this reason, as the measurement timing of the battery information for estimating the battery state, for example, the timing at which the inrush current flows is suitable, and the battery state of the lead battery is estimated using the battery information measured at this timing. Some battery state estimation devices have been put into practical use.

  However, when measuring the inrush current at the time of starting the engine, since the inrush current is a large current of 400A to 1300A, the current sensor is expensive and the cost of the entire apparatus is increased. Current sensors of full scales 100A to 200A that cannot measure inrush current at the time are used, and the current measured after the measurement timing is measured instead of the inrush current (see “Current measurement” in FIG. 6).

JP-A-7-63830 Japanese Patent No. 3172777

  However, although the above-described small full-scale current sensor is low in cost, after inrush current, the battery state must be estimated using the current after the current sensor enters the measurable current range. Since a large amount of electricity flows due to the inrush current, there is a problem that it is difficult to estimate the battery state accurately due to the influence of the concentration polarization of the engine starting battery.

  SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a battery state estimation device and a battery information notification device that can accurately estimate or obtain battery state or battery information of an engine starting battery using a small full-scale current sensor. And

In order to solve the above-mentioned problem, a first aspect of the present invention is a battery state estimation device for estimating a battery state of an engine starting battery, a voltage measuring unit for measuring the voltage of the battery, and a current flowing through the battery Current measuring means for measuring the voltage, storage means for storing the voltage measured by the voltage measuring means and the value of the current measured by the current measuring means at predetermined time intervals, and the value of the voltage stored in the storage means , It is determined whether or not there is a voltage drop equal to or greater than a preset value within a predetermined first predetermined time. If the determination is affirmative, the starter for starting the engine is when the starter switch for supplying power determination means for determining that the oN state, the determination means determines that the starter switch is turned on, the starter switch is O Calculates the value of the internal resistance of the battery from the value of the stored voltage and current before the storage means as a state, and estimating means for estimating a battery state of the battery from the value of the internal resistance that the operational, the And the estimation means, when the determination means determines that the starter switch is in an on state, the storage between the time 0 ms before and the time 10 ms before the determination by the determination means when the starter switch is in an on state. A pair of voltage and current values of the voltage and current values stored in the means, and the second predetermined time before the time 20 ms or more before the determination means determines that the starter switch is on. The internal resistance value is calculated using a pair of voltage and current values among the voltage and current values stored in the means .

In the first aspect, the voltage measured by the voltage measuring unit and the current value measured by the current measuring unit are stored in the storage unit every predetermined time. The determination means refers to the voltage value stored in the storage means, determines whether or not there is a voltage drop greater than a preset value within a predetermined first predetermined time, and makes a positive determination. when, it is determined that the starter switch is turned on, the estimation unit, when the determining means determines that the starter switch is turned on, is stored in front of the storage means the starter switch is turned on and calculating the voltage and the value of the internal resistance value from the battery current, but the battery state of the battery from the computed value of the internal resistance are estimated, the estimation means, the determination means starter switch is turned on and When the determination is made, a pair of voltage and current values stored in the storage means between the time 0 ms before and the time 10 ms before the time when the starter switch is turned on by the determination means are determined. And a pair of voltage and current values among the voltage and current values stored in the storage means before the second predetermined time 20 ms or more before the time when the starter switch is turned on by the determination means Is used to calculate the value of the internal resistance . After the ignition switch is positioned at the start terminal position, there is a time lag until the starter switch is turned on, during which load current flows from the battery to the starter switch solenoid. Since this load current is a relatively large value, the voltage can be measured with high accuracy, and the current can be measured even using a current measuring means having a small full scale.

In the first aspect, the storage means preferably stores the voltage measured by the voltage measurement means and the value of the current measured by the current measurement means in a cycle within 10 ms. It further comprises information acquisition means for acquiring IGN information indicating that the ignition switch (IGN) is positioned at the start terminal position from the vehicle control unit, and the determination means stores the information after the information acquisition means acquires the IGN information. It may be determined whether or not the starter switch is turned on by monitoring a change in the value of the voltage stored in .

In order to solve the above-described problem, a second aspect of the present invention provides a battery state estimation device for estimating a battery state of an engine starting battery, a voltage measuring unit that measures the voltage of the battery, and a battery Current measuring means for measuring a flowing current, storage means for storing the voltage measured by the voltage measuring means and the value of the current measured by the current measuring means at predetermined time intervals, and the voltage stored in the storage means Monitoring means for determining whether or not a starter switch for supplying electric power from the battery to the starter for starting the engine is turned on, and the determination means includes the starter switch When it is determined that the battery has been turned on, the voltage and current values stored in the storage means before the starter switch is turned on are used for the battery. Estimation means for estimating a battery state; and information acquisition means for acquiring IGN information indicating that an ignition switch (IGN) is positioned at a start terminal position from a vehicle control unit; and the determination means includes the information acquisition After the means acquires the IGN information, whether or not a starter switch for operating the starter for starting the engine is turned on by monitoring a change in the value of the voltage stored in the storage means. The storage means stores the voltage measured by the voltage measurement means and the value of the current measured by the current measurement means at a period exceeding 10 ms, and after the information acquisition means acquires the information For the next time, the voltage and voltage measured by the voltage measuring means within 10 ms from the last time the voltage and current values were stored. Storing the measured current in the current measuring means, characterized in that.

Furthermore, in order to solve the above-mentioned problem, a third aspect of the present invention is a battery information notification device that notifies the vehicle control unit of battery information of an engine starting battery, and a voltage measuring unit that measures the voltage of the battery. Current measuring means for measuring the current flowing through the battery, storage means for storing the voltage measured by the voltage measuring means and the value of the current measured by the current measuring means at predetermined intervals, and the storage means With reference to the stored voltage value, it is determined whether or not there is a voltage drop equal to or greater than a preset value within a first predetermined time, and the engine is started when an affirmative determination is made. Determining means for determining that a starter switch for supplying power from the battery to the starter is turned on, and when the determining means determines that the starter switch is turned on, The value of the internal resistance of the battery is calculated from the voltage and current values stored in the storage means before the starter switch is turned on, and the vehicle control is performed using the calculated internal resistance value as battery information of the battery. An informing means for informing the section, wherein when the judging means judges that the starter switch is in the on state, the judging means judges that the starter switch is in the on state from time 0 ms before From a pair of voltage and current values stored in the storage means between 10 ms before the time and a time 20 ms or more before the time when the starter switch is turned on by the judging means. The value of the internal resistance is calculated using a pair of voltage and current values among the voltage and current values stored in the storage means before the second predetermined time. To, characterized in that. According to a fourth aspect of the present invention, there is provided a battery information notifying device for notifying a vehicle control unit of battery information of an engine starting battery, measuring voltage of the battery, and measuring a current flowing through the battery. Current measuring means, storage means for storing the voltage measured by the voltage measuring means and the current value measured by the current measuring means at predetermined time intervals, and change in the voltage value stored in the storage means Monitoring means for determining whether or not a starter switch for supplying power from the battery to the starter for starting the engine is turned on, and the judging means determines that the starter switch is turned on. When it is determined that the starter switch is turned on, the voltage and current values stored in the storage means before the starter switch is turned on are used as the battery information of the battery. Informing means for informing both control parts, and information obtaining means for obtaining IGN information indicating that the ignition switch (IGN) is positioned at the start terminal position from the vehicle control part, and the judging means comprises the information Whether or not the starter switch for operating the starter for starting the engine is turned on by monitoring the change in the voltage value stored in the storage unit after the acquisition unit acquires the IGN information. The storage means stores the voltage measured by the voltage measurement means and the current value measured by the current measurement means at a period exceeding 10 ms, and the information acquisition means acquires the information. For the next one time, the voltage and voltage measured by the voltage measuring means within 10 ms from the time of storing the previous voltage and current values. Storing the measured current in the current measuring means, characterized in that. In the battery information notification device according to the third and fourth aspects, the battery state estimation device according to the first and second aspects estimates the battery state, whereas such estimation is performed on the vehicle control unit side. There is for notifying the vehicle control unit by a broadcast means battery information required for the estimation.

According to the first and second aspects of the present invention, since the battery state of the battery is estimated by the estimation means using the voltage and current values before the starter switch is turned on, the inrush current is included in the estimation. Since the current value measured before flowing is sufficient, it is possible to use a current measuring means with a small full scale, and since there is no influence of the concentration polarization of the battery due to the inrush current, the battery state can be estimated accurately. The effect that can be obtained. In addition, according to the third and fourth aspects, since the current before the inrush current flows is measured, current measuring means having a small full scale can be used, and there is no influence of the concentration polarization of the battery due to the inrush current. Therefore, an effect that accurate battery information can be notified to the vehicle control unit can be obtained.

It is a block wiring diagram of a battery state estimating device and a car of an embodiment to which the present invention is applicable. It is a flowchart of the battery state estimation routine which CPU of the microcomputer of the battery state estimation apparatus of embodiment performs. It is a graph which shows typically the voltage change and current change of a lead battery before and after a starter switch will be in an ON state. It is a graph which shows the SOH map stored in ROM of the microcomputer. It is a graph which shows the relationship between the SOH estimated value calculated by the battery state estimation apparatus of an Example and a comparative example, and SOH actual value. It is a graph which shows typically the waveform of the voltage and current of a lead battery at the time of engine starting.

  Hereinafter, referring to the drawings, the battery state of a lead battery for engine start mounted in a gasoline vehicle (hereinafter referred to as ISS vehicle) having an idle stop / start function (hereinafter referred to as ISS function) will be described. An embodiment applied to a battery state estimation device to be estimated will be described.

(Constitution)
As shown in FIG. 1, the battery state estimation device 10 of the present embodiment has a current sensor 2 such as a Hall sensor that measures the current flowing in the lead battery 1, a differential amplifier circuit, and measures the voltage across the lead battery 1. And a temperature sensor 4 such as a thermistor for measuring the temperature of the lead battery 1, and a microcomputer (hereinafter referred to as a microcomputer) 5 for estimating the battery state of the lead battery 1.

  The lead battery 1 has a rectangular battery case serving as a battery container. As the material of the battery case, a polymer resin such as polypropylene (PP) or polyethylene (PE) that is excellent in terms of moldability, electrical insulation, corrosion resistance, durability, and the like can be selected. A sensor insertion hole is formed in the partition wall at the center of the battery case. A temperature sensor 4 is inserted into the sensor insertion hole, and is fixed in the sensor insertion hole with an adhesive. A total of six sets of electrode plates are accommodated in the battery case. In each electrode plate group, a plurality of negative electrodes and positive electrodes are laminated via a retainer (separator) made of glass fiber, and the cell voltage is 2.0V. Therefore, the nominal voltage of the lead battery 1 is 12V. The upper part of the battery case is bonded or welded to an upper lid made of a polymer resin such as PP or PE that seals the upper opening of the battery case. A rod-shaped positive external terminal and negative external terminal for supplying electric power to the outside using the lead battery 1 as a power source are erected on the upper lid.

  A positive external terminal of the lead battery 1 is connected to a central terminal of an ignition switch (hereinafter abbreviated as IGN) 21 via a current sensor 2. The IGN21 has an OFF terminal, ON / ACC terminal, and START terminal (start terminal) separately from the central terminal, and the central terminal and any of these OFF, ON / ACC, and START terminals are switched to a rotary type. Connection is possible.

  The START terminal is connected to one end of a cell motor (starter) 23 that starts the engine 24 via a starter switch 22. Since a large inrush current flows from the lead battery 1 to the cell motor 23, a relay is used for the starter switch 22. When the IGN 21 is positioned (switched) at the START terminal position, the starter switch 22 is controlled to be turned on by the vehicle ECU 20. In other words, a normal engine vehicle having no ISS function may be directly connected from the IGN 21 to the starter switch 22, but in an ISS vehicle, the engine 24 is restarted (idle start) after an idle stop due to a signal or the like. Therefore, it is determined whether or not the cell motor 23 can be operated with the electric power of the lead battery 1 (whether the engine can be restarted), and when possible, the cell motor 23 is operated with the electric power of the lead battery 1. Necessary. The cell motor 23 can transmit rotational driving force to the rotation shaft of the engine 24 via a clutch mechanism (not shown).

  The ON / ACC terminal is connected to one end of a generator 25 that generates electric power by rotation of the engine 24 via an auxiliary device 26 such as an air conditioner, a radio, and a lamp and a rectifier that allows a current flow in one direction. . That is, the anode side of the rectifier is connected to one end of the generator 25, and the cathode side is connected to the ON / ACC terminal. The rotating shaft of the engine 24 can transmit power to the generator 25 via a clutch mechanism (not shown). For this reason, when the engine 24 is in a rotating state, the generator 25 is operated via a clutch mechanism (not shown), and electric power from the generator 25 is supplied (charged) to the auxiliary machine 26 and the lead battery 1. Note that the OFF terminal is not connected to any of them.

  The other end of the cell motor 23, the generator 25 and the auxiliary machine 26, and the negative electrode external terminal of the lead battery 1 are connected to the ground having the same potential as that of the automobile chassis. One end of the auxiliary machine 26 is connected to the ON / ACC terminal via a relay whose on / off is controlled by the vehicle ECU 20, but such a relay is omitted in FIG.

  The positive and negative external terminals of the lead battery 1 are connected to the voltage measurement circuit 3, and the output side of the voltage measurement circuit 3 is connected to an A / D converter built in the microcomputer 5. For this reason, the microcomputer 5 can take in the voltage of the lead battery 1 as a digital value. Similarly, the output terminals of the current sensor 2 and the temperature sensor 4 are respectively connected to an A / D converter built in the microcomputer 5. For this reason, the microcomputer 5 can capture the current flowing in the lead battery 1 and the temperature of the lead battery 1 as digital values.

  The microcomputer 5 functions as a CPU that functions as a central processing unit, a basic control program for the battery state determination device 10 and a ROM that stores program data such as mathematical formulas and maps, which will be described later, and a work area for the CPU. It includes a RAM for storing, a ring buffer for storing values of voltages and currents measured via the voltage measuring circuit 3 and the current sensor 2, a communication unit for communicating with the vehicle ECU 20, and the like. The microcomputer 5 is connected to the vehicle ECU 20 via a communication line, and is also connected to the ground having the same potential as the chassis of the ISS vehicle. Each A / D converter of the microcomputer 5 samples the voltage of the lead battery 1 and the current flowing through the lead battery 1 at intervals of 1 millisecond (1 ms), and samples the temperature of the lead battery 1 at intervals of 1 second (1 s). To do. Although the ring buffer is not always necessary, for example, the processing time is significantly shortened as compared with the case where the ring buffer is stored in the RAM. Therefore, in the present embodiment, the configuration in which the voltage and current values are stored in the ring buffer is adopted. . Further, the microcomputer 5 operates with the electric power of the lead battery 1 through a power supply circuit (not shown).

  The vehicle ECU 20 is connected to the IGN 21 and the engine 24, and the vehicle ECU 20 can grasp at which terminal position the IGN 21 is positioned and the state of the engine 24. Further, when the vehicle ECU 20 obtains information (SOH and SOC described later) on the battery state of the lead battery 1 from the microcomputer 5 via a communication line connected to the microcomputer 5 and performs idle stop. Whether the engine 24 can be restarted with the electric power of the lead battery 1 is determined before the idle stop.

(Operation)
Next, with reference to a flowchart, the operation of the battery state estimation device 10 of the present embodiment will be described with the CPU of the microcomputer 5 as a subject. When the microcomputer 5 is powered on, the CPU executes a battery state estimation routine for estimating the battery state of the lead battery 1 shown in FIG. The program and program data stored in the ROM are expanded in the RAM by an initial setting process (not shown) after turning on the power to the microcomputer 5.

  As shown in FIG. 2, in the battery state estimation routine, in step 102, the polarization is accumulated while the lead battery 1 is being discharged (during driving of the vehicle), and the polarization is not released. Wait until the voltage stabilizes. That is, by determining whether or not a predetermined time (for example, 6 hours) has elapsed after the engine is stopped, it is determined that the voltage of the lead battery 1 is stable at the time of an affirmative determination. Whether or not the engine 24 has stopped may be determined by monitoring the voltage of the lead battery 1 measured by the voltage measurement circuit 3 and determining the engine stop by the microcomputer 5, for example, as will be described later. You may receive notification from.

  Next, at step 104, the open circuit voltage OCV of the lead battery 1 is measured. That is, the voltage of the lead battery 1 output from the voltage measurement circuit 3 is captured as a digital value via the A / D converter and stored in the RAM. Next, in step 106, the voltage of the lead battery 1 output from the voltage measurement circuit 3 and the value of the current output from the current sensor 2 are respectively taken in digital values every 1 ms via the A / D converter, and the ring buffer Store (memorize).

  In the next step 108, the temperature value of the lead battery 1 output from the temperature sensor 4 is captured as a digital value every 1 s through the A / D converter and stored in the RAM. Since this process is performed every 1 s, it is actually determined whether or not 1 s has elapsed since the previous temperature measurement. If it is determined that the time has not elapsed, the process proceeds to the next step 110, and the previous This is performed when it is determined that 1 s has elapsed since the temperature measurement. Next, in step 110, a change in the voltage value stored in the ring buffer is monitored, specifically, by referring to the voltage value stored in the ring buffer every 1 ms, 50 ms (first predetermined time). ) Is determined whether or not there is a voltage drop of 1.5V (preset value) or more.

  Here, with reference to FIG. 3, the acquisition principle of the battery information of the lead battery 1 by the battery state estimation apparatus 10 of this embodiment is demonstrated.

  When the IGN 21 is positioned at the START terminal position by the driver, the vehicle ECU 20 controls the starter switch 22 to be in an ON state, and power is supplied from the lead battery 1 to the solenoid of the starter switch 22. As a result, the starter switch 22 (the contact of the magnet switch) is turned on, and power supply to the cell motor 23 from the lead battery 1 is started. As a result, a large inrush current starts to flow through the cell motor 23. Next, the rotating shaft of the cell motor 23 rotates, the rotational driving force is transmitted to the rotating shaft of the engine 24 via a clutch mechanism (not shown), and the engine 24 is started.

  There is a time lag of about 20 ms from when the IGN 21 is positioned at the START terminal position until the starter switch 22 is turned on, during which load current flows through the solenoid of the starter switch 22. This current value takes about 10 ms for the current to stabilize after the IGN 21 is positioned at the START terminal position. After that, the remaining 10 ms until the starter switch 22 is turned on is generally 40 A or more and a relatively large current is stabilized. Flowing. As described above, since the load current flows through the solenoid of the starter switch 22, the voltage of the lead battery 1 also decreases, so that the voltage change can be sufficiently measured. In step 110, it is determined whether or not the starter switch 22 has been turned on by considering whether or not there is a voltage drop of 1.5 V or more within 50 ms in consideration of the voltage drop due to the load current. It is. The current and voltage are both stable for a period of approximately 10 ms to 0 ms before the inrush current flows, the variation in the current value at each engine start is small, and the value is 100 A or less. Therefore, the battery information of the lead battery 1 is accurately measured by using the voltage and current values measured at this timing (from when the IGN 21 is positioned at the START terminal position until the starter switch 22 is turned on). Is possible. Note that the internal resistance of the lead battery 1 is generally current-dependent, but current correction is unnecessary because the current value of 40 A or more is almost constant.

  When a negative determination is made at step 110, it is considered that the starter switch 22 is still in an off state, and the process returns to step 106. When an affirmative determination is made, it is assumed that the starter switch 22 is controlled to be in an on state. The storage of the value in the ring buffer is stopped, and the process proceeds to the next step 112.

  In step 112, among the voltage value and the current value stored in the ring buffer, the voltage value V2, the current value I2, and the starter switch 22 from 10 ms to 0 ms before it is determined that the starter switch 22 is turned on are A voltage value V1 and a current value I1 that are 20 ms or more before it is determined to be in the on state are extracted.

  In the next step 114, the value of the internal resistance R of the lead battery 1 is calculated by the following equation (1) using the voltage value and the current value extracted in step 112. If the measurement timing of the voltage value V1 and the current value I1 is too early, the polarization due to the current flowing until the IGN 21 is positioned at the START terminal position becomes an error factor in the internal resistance R calculation. Therefore, the voltage value V1 and the current value I1 are as much as possible. , IGN21 is preferably a value immediately before being positioned at the START terminal position. Actually, even if the oldest value of the ring buffer is used, the expected time range of the data that can be accommodated in the ring buffer is as short as about 50 ms (first predetermined time), so that the starter switch 22 is turned on in the ring buffer. As long as the voltage value V1 and the current value I1 are selected from data 20 ms or more before it is determined that the IGN 21 is determined, it may be considered that the value is just before the IGN 21 is positioned at the START terminal position.

  Next, in step 116, the battery state of the lead battery 1 is estimated (calculated), the estimation result is notified to the vehicle ECU 20, and the battery state estimation routine is terminated. Below, the estimation method of SOH and SOC of the lead battery 1 is illustrated as an example, but other known estimation methods may be used.

  The SOH of the lead battery 1 can be estimated by applying a lead battery having the same specifications as that of the lead battery 1 to an SOH map representing the relationship between the internal resistance R and SOH measured in advance in various deterioration states. Battery SOH is generally defined as degraded full charge capacity / new full charge capacity x 100%, and is expressed as a function of internal resistance R, temperature T, and open circuit voltage OCV as shown in the following equation (2). The

  FIG. 4 shows a determination map at 25 ° C. By using a conversion formula for converting the value of the internal resistance R to 25 ° C., SOH can be estimated using the SOH map shown in FIG. Although the strict definition of the open circuit voltage OCV is an open circuit voltage at zero current, as described above, in this embodiment, the stable voltage of the lead battery 1 when a predetermined time has elapsed after the engine is stopped is an open circuit voltage. The voltage was considered as OCV.

  On the other hand, the SOC is estimated (calculated) by converting the OCV into the remaining capacity as an argument of the SOC map together with the temperature and dark current value, and correcting the obtained remaining capacity by the following equation (3) using SOH. Is done.

  On the other hand, when the vehicle speed becomes zero, the vehicle ECU 20 determines whether to stop the engine 24 (IS determination), in addition to the vehicle state such as shift and brake, as well as the SOH notified from the battery state estimation device 10. And the SOC value is used. The values of SOH and SOC notified from the battery state estimation device 10 can be easily used when the vehicle ECU 20 makes an IS determination. Therefore, the SOC that can be restarted with the current temperature T and SOH is set to SOC = 0, the current temperature T It is desirable that the SOH that can restart the engine is defined as SOH = 0. Otherwise, when using the general SOC definition SOC = 100% × remaining capacity / full charge capacity, the general SOH definition SOH = degraded product full charge capacity / new full charge capacity × 100%, Every time SOH and SOC are notified from the battery state estimation device 10 to the vehicle ECU 20, the SOC reference value at which the engine can be restarted and the SOH reference value at which the engine can be restarted must also be notified. It is preferable that the SOC reference value at which the engine can be restarted and the SOH reference value at which the engine can be restarted at the current temperature are stored in advance in the storage device on the vehicle ECU 20 side.

(Action etc.)
Next, effects and the like of the battery state estimation device 10 of the present embodiment will be described.

  In the battery state estimation device 10 of the present embodiment, the lead battery 1 is used by using the voltage and current values before the starter switch 22 is turned on after the IGN 21 is positioned at the START terminal position (see step 112 in FIG. 2). Since the battery state is estimated, the estimated value is the current measured before the inrush current flows (current measured every 1 ms from “connected to IGN START terminal” to “start switch on” in FIG. 3). Therefore, a current sensor with a small full scale can be used, and since there is no influence of concentration polarization of the lead battery 1 due to the inrush current, the battery state of the lead battery 1 can be estimated accurately.

  Further, in the battery state estimation device 10 of the present embodiment, the voltage measured by the voltage measurement circuit 3 and the current value measured by the current sensor 2 are stored in a ring buffer every 1 ms, and changes in those values are monitored. Therefore, it can be determined in real time that the start switch 22 has been turned on (step 110), and the voltage value stored in the ring buffer at a cycle within 10 ms (in this embodiment, every 1 ms) and Since the value of the internal resistance R is calculated with reference to the current value (steps 112 and 114), the internal resistance value R of the lead battery 1 and thus the battery state (SOH, SOC) of the lead battery 1 are calculated with high accuracy. (Step 116).

  On the other hand, if the voltage value and current value are stored in the ring buffer at a period exceeding 10 ms, it may not be possible to measure by skipping 40 A or more 10 ms data immediately before the inrush current. I2 cannot be measured, and the estimation accuracy of the battery state of the lead battery 1 decreases.

  Further, in the battery state estimation device 10 of the present embodiment, when it is determined that the starter switch 22 is turned on (step 110 in FIG. 2), from the time 0 ms before the time when the starter switch 22 is turned on to 10 ms before the time. A pair of voltage value V2 and current value I2 of the voltage and current values stored in the ring buffer in the meantime, and a second predetermined time of 20 ms or more from the time when the starter switch 22 is turned on (this embodiment) In this case, the internal resistance value R is calculated using the pair of voltage value V1 and current value I1 among the voltage and current values stored in the ring buffer before 30 ms), as described in the battery information acquisition principle. The battery information of the lead battery 1 can be acquired accurately.

  In the present embodiment, the voltage of the lead battery 1 and the value of the current flowing in the lead battery 1 are constantly monitored to determine whether or not the starter switch 22 is turned on (step 106). 110), the present invention is not limited to this. For example, the microcomputer 5 acquires IGN information indicating that the IGN 21 is positioned at the start terminal position from the vehicle ECU 20 (for example, the vehicle ECU 20 is connected to the microcomputer 5 via a communication line or a signal line). When the IGN 21 is positioned at the START position, the microcomputer 5 outputs a high signal of the binary values, and when the IGN 21 is positioned at a position other than the START position, the microcomputer 5 outputs the IGN 21 to the microcomputer 5. In this case, the voltage of the lead battery 1 and the value of the current flowing through the lead battery 1 from the time of acquisition may be stored in the ring buffer. In such an aspect, except for the case where the OCV is measured in step 104, the microcomputer 5 operating with the lead battery 1 as the power source can be maintained in a sleep state with low power consumption before the IGN information is acquired. The self-power consumption of the lead battery 1 can be suppressed.

  Moreover, in this embodiment, in order to estimate the battery state of the lead battery 1 by the battery state estimation device 10 with high accuracy, an example in which the voltage value and the current value are stored in the ring buffer at a cycle within 10 ms is shown. When the above-mentioned IGN information can be acquired from the vehicle ECU 20, the voltage value and the current value are stored in the ring buffer at a cycle exceeding 10 ms, and the next time after the acquisition of the IGN information, the previous voltage value and The voltage value and the current value may be stored within 10 ms from the time when the current value is stored, and these values may be used for the calculation of the value of the internal resistance R. Or after acquiring IGN information, you may make it change a storage rate so that the value of a voltage and an electric current may be stored in a ring buffer with a period within 10 ms immediately.

  Furthermore, in this embodiment, although the example which estimates the battery state of the lead battery 1 by the battery state estimation apparatus 10 side was shown, you may make it perform such estimation by vehicle ECU20 side. In that case, the current sensor 2, the voltage measurement circuit 3, the temperature sensor 4, and the microcomputer 5 function as a battery information notification device that notifies the vehicle ECU of the battery information of the lead battery 1. In such a battery information notification device, instead of steps 114 and 116 shown in FIG. 2, the open circuit voltage OCV and battery temperature T of the lead battery 1 stored in the RAM in steps 104 and 108, and extracted in step 112. The battery information may be notified to the vehicle ECU 20.

  Further, in the present embodiment, in order to determine the ON state of the starter switch 22, the first predetermined time is 50 ms and the preset value is 1.5 V (see step 110 in FIG. 2). Is not limited to this, and takes into account the time from when the vehicle ECU 20 grasps the switching of the IGN 21 to the START terminal position until the starter switch 22 is turned on, and the characteristics of the starter switch 22 and the cell motor 23. Can be set.

  Further, in this embodiment, the voltage value V2 and the current value I2 10 ms before it is determined that the starter switch 22 is turned on, and the voltage value V1 20 ms before that the starter switch 22 is determined to be turned on. However, the present invention is not limited to this. For example, the current value I1 is stored in the ring buffer between the time 0 ms before the time 10 ms and the time 10 ms before the starter switch 22 is turned on. A pair of voltage and current values among the stored voltage and current values, and the pair of voltage and current values were stored in the ring buffer a predetermined time within 10 ms from the stored time. Of the voltage and current values, a pair of voltage and current values may be used.

  Next, an example of the battery state estimation device 10 manufactured according to the above-described embodiment will be described. A comparative example is also shown.

Example 1
The engine was started with an OCV of 12.4 V, a temperature of 25 ° C., and a 55B24 battery in various deterioration states, and currents and voltages 30 ms before and 5 ms before the inrush current flow were measured. As the current sensor, a ± 100 A hall type sensor was used. The sampling period of current and voltage was 1 ms. Assuming that the voltage 30 ms before the inrush current flows is V1, the current is I1, the voltage 5 ms before the inrush current flows is V2, and the current is I2, the value of the internal resistance R is calculated by the above equation (1), and the equation (2 ) To calculate SOH.

(Comparative Example 1)
Except for measuring the current and voltage 30 ms before the inrush current flows and 30 ms after the inrush current starts flowing, the same battery and current sensor as in Example 1 are used. The voltage 30 ms before the inrush current flows is V1, the current Where I1 is the voltage, V2 is the voltage 30 ms after the first inrush current flows, and I2 is the current, and the value of the internal resistance R is calculated by the above equation (1), and SOH is calculated by the equation (2). Note that the voltage V2 and the current I2 in Comparative Example 1 are values of voltage and current when the current first becomes less than −95 A after the inrush current flows.

  FIG. 5 shows SOH estimated by the battery state estimation device 10 of Example 1 and SOH estimated by the battery state estimation device of Comparative Example 1. The actual measurement values in FIG. 5 are obtained as a percentage of the amount of electricity when fully discharged and discharged to 10.5 V with a 5-hour rate discharge based on the new full charge capacity, with respect to the new full charge capacity. . As shown in FIG. 5, the battery state estimation device 10 of Example 1 was closer to the actually measured value than the battery state estimation device of Comparative Example 1. Therefore, it turns out that the battery state estimation apparatus 10 of Example 1 is excellent.

  The present invention provides a battery state estimation device and a battery information notification device that can accurately estimate or obtain battery state or battery information of an engine starting battery using a small full-scale current sensor. Since it contributes to the manufacture and sale of devices and battery information notification devices, it has industrial applicability.

1 Lead battery (battery)
2 Current sensor (part of current measurement means)
3 Voltage measurement circuit (part of voltage measurement means)
5 Microcomputer (storage means, judgment means, estimation means, information acquisition means)
10 battery state estimation device 20 vehicle ECU (vehicle control unit)
21 Ignition switch 22 Starter switch 23 Cell motor (starter)

Claims (6)

In the battery state estimation device for estimating the battery state of the engine starting battery,
Voltage measuring means for measuring the voltage of the battery;
Current measuring means for measuring the current flowing through the battery;
Storage means for storing the voltage measured by the voltage measuring means and the value of the current measured by the current measuring means every predetermined time;
With reference to the voltage value stored in the storage means, it is determined whether or not there is a voltage drop equal to or greater than a preset value within a predetermined first predetermined time. determining means for determining a starter switch for supplying power from the battery to the starter for starting the engine is turned on,
When the determination means determines that the starter switch is turned on, the value of the internal resistance of the battery is calculated from the voltage and current values stored in the storage means before the starter switch is turned on. Estimating means for estimating the battery state of the battery from the calculated value of internal resistance ;
Equipped with a,
When the determination unit determines that the starter switch has been turned on, the estimation unit stores in the storage unit between 0 ms before the time and 10 ms before the determination by the determination unit that the starter switch is in the on state. A pair of voltage and current values out of the stored voltage and current values, and a second predetermined time before the time 20 ms or more before the starter switch is determined to be in the ON state by the determination unit, are stored in the storage unit. Calculating the value of the internal resistance using a pair of voltage and current values out of the stored voltage and current values;
A battery state estimation device. 2. The battery state estimation apparatus according to claim 1, wherein the storage unit stores a voltage measured by the voltage measurement unit and a current value measured by the current measurement unit in a cycle of 10 ms or less.   It further comprises information acquisition means for acquiring IGN information indicating that the ignition switch (IGN) is positioned at the start terminal position from the vehicle control unit, and the determination means, after the information acquisition means acquires the IGN information, 2. It is determined whether a starter switch for operating a starter for starting the engine is turned on by monitoring a change in a voltage value stored in the storage means. The battery state estimation apparatus as described in. In the battery state estimation device for estimating the battery state of the engine starting battery,
Voltage measuring means for measuring the voltage of the battery;
Current measuring means for measuring the current flowing through the battery;
Storage means for storing the voltage measured by the voltage measuring means and the value of the current measured by the current measuring means every predetermined time;
Determining means for determining whether a starter switch for supplying electric power from the battery to the starter for starting the engine is turned on by monitoring a change in the value of the voltage stored in the storage means; ,
When the determination unit determines that the starter switch is turned on, the battery state of the battery is estimated using the voltage and current values stored in the storage unit before the starter switch is turned on. An estimation means to
Information acquisition means for acquiring IGN information representing that the ignition switch (IGN) is positioned at the start terminal position from the vehicle control unit;
With
The determination unit includes a starter switch that operates a starter for starting the engine by monitoring a change in a voltage value stored in the storage unit after the information acquisition unit acquires the IGN information. Determine if it ’s turned on,
The storage means stores the voltage measured by the voltage measurement means and the value of the current measured by the current measurement means at a period exceeding 10 ms, and the information acquisition means obtains the next value after acquiring the information. For the first time, the voltage measured by the voltage measuring means and the current value measured by the current measuring means are stored within 10 ms from the time when the voltage and current values were previously stored .
It characterized batteries state estimating device that. In the battery information notifying device for notifying the vehicle control unit of the battery information of the engine starting battery,
Voltage measuring means for measuring the voltage of the battery;
Current measuring means for measuring the current flowing through the battery;
Storage means for storing the voltage measured by the voltage measuring means and the value of the current measured by the current measuring means every predetermined time;
With reference to the voltage value stored in the storage means, it is determined whether or not there is a voltage drop equal to or greater than a preset value within a predetermined first predetermined time. determining means for determining a starter switch for supplying power from the battery to the starter for starting the engine is turned on,
When said determination means determines that the starter switch is turned on, calculates the value of the internal resistance of the battery from the value before the storage means to the stored voltage and current which the starter switch is turned on And notifying means for notifying the vehicle control unit of the calculated value of the internal resistance as battery information of the battery;
Equipped with a,
When the determination unit determines that the starter switch is turned on, the notification unit stores in the storage unit between 0 ms before the time and 10 ms before the determination by the determination unit that the starter switch is turned on. A pair of voltage and current values out of the stored voltage and current values, and a second predetermined time before the time 20 ms or more before the starter switch is determined to be in the ON state by the determination unit, are stored in the storage unit. Calculating the value of the internal resistance using a pair of voltage and current values out of the stored voltage and current values;
The battery information alerting device characterized by the above-mentioned . In the battery information notifying device for notifying the vehicle control unit of the battery information of the engine starting battery,
Voltage measuring means for measuring the voltage of the battery;
Current measuring means for measuring the current flowing through the battery;
Storage means for storing the voltage measured by the voltage measuring means and the value of the current measured by the current measuring means every predetermined time;
Determining means for determining whether a starter switch for supplying electric power from the battery to the starter for starting the engine is turned on by monitoring a change in the value of the voltage stored in the storage means; ,
When the determination unit determines that the starter switch is turned on, the vehicle control is performed using the voltage and current values stored in the storage unit before the starter switch is turned on as battery information of the battery. Notification means for notifying the section;
Information acquisition means for acquiring IGN information representing that the ignition switch (IGN) is positioned at the start terminal position from the vehicle control unit;
With
The determination unit includes a starter switch that operates a starter for starting the engine by monitoring a change in a voltage value stored in the storage unit after the information acquisition unit acquires the IGN information. Determine if it ’s turned on,
The storage means stores the voltage measured by the voltage measurement means and the value of the current measured by the current measurement means at a period exceeding 10 ms, and the information acquisition means obtains the next value after acquiring the information. For the first time, the voltage measured by the voltage measuring means and the current value measured by the current measuring means are stored within 10 ms from the time when the voltage and current values were previously stored.
The battery information alerting device characterized by the above-mentioned.

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