JP2007216707A - Device and method for determining battery degradation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery degradation determination device capable of adequately determining degradation of a battery based on the internal resistance of the battery. <P>SOLUTION: An internal resistance calculation means 1b calculates the actual internal resistance of a battery 2 from the voltage amplitude and the current amplitude of the battery 2 when an engine is started. A battery degradation determination means 1d determines degradation of the battery 2 by the calculated actual internal resistance and the internal resistance for determination in which the power of the battery 2 stored in advance in an internal resistance storage means 1c is normal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a battery deterioration determination device and a battery deterioration determination method, and more particularly to a battery deterioration determination device and a battery deterioration determination method for determining deterioration of a vehicle battery.

  In recent years, with the rapid spread of automobiles, there is an increasing need for improving the comfort, safety and convenience of automobiles. For this reason, the number of in-vehicle electrical components such as air conditioners and navigations attached to automobiles is increasing rapidly. As a result, the load on the battery increases, and there is a concern that the battery will deteriorate or run out.

Therefore, there is a conventional battery deterioration determination device that performs battery deterioration determination based on a decrease in battery voltage when the engine is started. Conventionally, the current amount integrating means integrates the output current and regenerative current of the battery from when the remaining battery capacity is set to the first value until it reaches the second value, and the deterioration determining means uses this integrated value. There is a battery deterioration determination device that determines whether or not the battery is deteriorated when the battery is below a preset deterioration determination value (see Patent Document 1).
Japanese Patent No. 3545240

  However, if there is an abnormality or failure in parts or devices to which battery power is supplied, a significant voltage drop may occur. There was a problem that there was a risk of being.

For example, when the starter is bitten and a large voltage drop occurs, it may be determined that the battery is deteriorated even though the battery is normal.
The present invention has been made in view of these points, and an object of the present invention is to provide a battery deterioration determination device and a battery deterioration determination method that appropriately determine the deterioration of the battery based on the internal resistance of the battery.

  In the present invention, in order to solve the above problem, voltage detection means for detecting a voltage fluctuation width of the battery at the time of starting the engine, current detection means for detecting a current fluctuation width of the battery at the time of engine startup, and the voltage fluctuation An internal resistance calculating means for calculating an actual internal resistance of the battery from a width and the current fluctuation width; an internal resistance storing means for storing an internal resistance for determination that the battery is normal; and the actual internal resistance and the There is provided a battery deterioration determination device comprising battery deterioration determination means for determining deterioration of the battery by a determination internal resistance.

  According to such a battery deterioration determination device, the actual internal resistance of the battery is calculated from the voltage fluctuation width and current fluctuation width of the battery when the engine is started. Then, the deterioration of the battery is determined based on the calculated actual internal resistance and the determination internal resistance that is stored in advance in the internal resistance storage means so that the battery power is normal. As a result, even if there is an abnormality in a component, device, or the like to which the battery power is supplied, the internal resistance of the battery is not affected, so that the battery deterioration can be properly determined.

  According to the battery deterioration determination device of the present invention, the actual internal resistance of the battery is calculated from the voltage fluctuation width and current fluctuation width of the battery at the time of starting the engine. Then, the deterioration of the battery is determined based on the calculated actual internal resistance and the determination internal resistance stored in advance in the internal resistance storage means.

  In this way, the internal resistance of the battery is calculated and the deterioration of the battery is determined. Therefore, even if there is an abnormality in the parts and devices to which the battery power is supplied, the battery deterioration is properly determined. It can be carried out.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a conceptual diagram of the invention applied to this embodiment. As shown in FIG. 1, a battery deterioration determination device 1 and a battery 2 are connected. The battery deterioration determination device 1 includes voltage / current detection means 1a, internal resistance calculation means 1b, internal resistance storage means 1c, and battery deterioration determination means 1d. In the present embodiment, the voltage / current detection means 1a is integrated, but the voltage detection means and the current detection means may be separate. The battery deterioration determination device may be integrated with another control device such as an engine control device or a power supply control device.

  The voltage / current detection means 1a detects a voltage fluctuation width which is the maximum value of the voltage fluctuation width output from the battery 2 and a current fluctuation width which is the maximum value of the current fluctuation width. The internal resistance calculation means 1b calculates the internal resistance of the battery from the voltage fluctuation width and current fluctuation width detected by the voltage / current detection means 1a. The internal resistance storage means 1c stores internal resistance when the battery 2 is normal, that is, when the battery 2 is not deteriorated. The battery deterioration determination unit 1d compares the actual internal resistance calculated by the internal resistance calculation unit 1b with the determination internal resistance stored in the internal resistance storage unit 1c, and determines whether or not the battery 2 has deteriorated. To do.

  Thus, both the voltage fluctuation width and the current fluctuation width are detected, the actual internal resistance is calculated, and compared with the determination internal resistance. It is known that when the battery 2 deteriorates, the value of the internal resistance of the battery 2 increases, and even if there is an abnormality in the parts, devices, etc. to which the power of the battery 2 is supplied, it is properly deteriorated. Can be determined.

Next, an embodiment when the battery deterioration determination device of the present invention is applied to a master ECU will be described in detail with reference to the drawings.
FIG. 2 is a diagram illustrating a system configuration example according to the present embodiment. As shown in FIG. 2, sensor values of a master ECU (Electronic Control Unit) 100, a battery 200, an alternator (ALT) 300, and a starter (STT) 400 are connected via a bus 500. In addition, a notification unit 600 is connected to the master ECU 100.

  The master ECU 100 detects the voltage immediately before starting which is the output voltage of the battery 200 immediately before starting the starter 400 and the minimum voltage at starting which is the lowest output voltage of the battery 200 when starting the starter 400. Further, a current amount immediately before starting which is the current amount of the battery 200 immediately before starting the starter 400 and a maximum current amount at starting which is the maximum discharge current amount of the battery 200 when starting the starter 400 are detected. At that time, the liquid temperature of the battery liquid that is the electrolyte of the battery 200 (hereinafter referred to as the battery liquid temperature) is detected.

  Then, from the voltage immediately before starting and the minimum voltage at starting, the starter 400 is calculated from the voltage fluctuation width which is the maximum value of the voltage fluctuation when starting the starter 400, the current amount immediately before starting and the maximum current amount at starting. The current fluctuation width which is the maximum value of the current fluctuation amplitude when the motor is started is obtained, and the ratio of the voltage fluctuation width and the current fluctuation width is calculated.

  Master ECU 100 also includes a storage device that stores a ratio of current fluctuation width to voltage fluctuation width (hereinafter referred to as a theoretical ratio) when battery 200 is normal for each battery liquid temperature. The master ECU 100 acquires a theoretical ratio corresponding to the battery liquid temperature acquired when starting the starter 400 from the storage device, and calculates the ratio of the current fluctuation width and the voltage fluctuation width of the battery 200 calculated when the starter 400 is started. In comparison, the deterioration of the battery 200 is determined. And when it determines with the battery 200 having deteriorated, it alert | reports using the alerting | reporting part 600. FIG.

  The battery 200 supplies power to the electrical components mounted on the automobile. The battery 200 is connected to a voltmeter 210 that measures the output voltage, an ammeter 220 that measures the amount of current, and a liquid thermometer 230 that measures the battery liquid temperature.

  The alternator 300 supplies power to the battery 200 and charges it while the engine of the automobile is being driven. In addition to the battery 200, power is also supplied to auxiliary machines such as a computer and a fuel injection injector in the vehicle. The starter 400 receives electric power from the battery 200 and starts an automobile engine.

  FIG. 3 is a diagram illustrating a hardware configuration example of the master ECU used in the present embodiment. As shown in FIG. 3, the master ECU 100 includes a microcomputer 101, an I / F (InterFace) 102, and a bus 103, and is connected to, for example, an external bus 500 via the I / F 102. Yes.

  The microcomputer 101 includes a CPU (Central Processing Unit) 101a, a ROM (Read Only Memory) 101b, and a RAM (Random Access Memory) 101c. As for master ECU100, the whole apparatus is controlled by CPU101a. A ROM 101b and a RAM 101c are connected to the CPU 101a via a bus 101d inside the microcomputer 101.

  The RAM 101c temporarily stores at least part of an OS (Operating System) program and application programs to be executed by the CPU 101a. The RAM 101c stores various data necessary for processing by the CPU 101a. The ROM 101b stores an OS and application programs.

  Note that the hardware of the master ECU 100 is not limited to the configuration shown in FIG. For example, a ROM may be connected to the bus 103, and the OS and application programs may be stored in the ROM. Alternatively, a RAM may be connected to the bus 103, and data may be temporarily stored in the RAM. With the hardware configuration as described above, the processing functions of the present embodiment can be realized.

Next, processing functions of the master ECU 100 will be described.
FIG. 4 is a diagram showing processing functions of the master ECU of the present embodiment. As shown in FIG. 4, the master ECU 100 includes a battery state detection unit 110, a counter 120, a predetermined time determination unit 130, a time comparison unit 140, a battery deterioration determination unit 150, and a theoretical ratio storage unit 160. In addition, a notification unit 600 is connected to the master ECU 100.

  The battery state detection unit 110 detects a voltage value, a current value, and a battery liquid temperature from the voltmeter 210, the ammeter 220, and the liquid thermometer 230 connected to the battery 200. The detected information is used to determine whether or not the battery 200 has deteriorated. It is known that the internal resistance of the battery 200 increases when it deteriorates. Since (voltage value) = (current value) × (resistance value), the ratio of the voltage fluctuation width to the current fluctuation width is obtained, and compared with the theoretical ratio stored in the theoretical ratio storage unit 160, the battery 200 is deteriorated. It can be determined whether or not.

  The counter 120 performs a count for measuring an elapsed time for determining whether or not the internal state of the battery 200 is stable. The counter 120 is cleared in response to a clear signal from the battery state detection unit 110. When the counter 120 receives an engine stop signal notifying that the engine has stopped from an ECU provided in an engine (not shown), the counter 120 is cleared. That is, the time is measured by the counter 120 in order to determine whether or not the internal state of the battery 200 is stable with the passage of time from when the engine is turned off or when a predetermined discharge has occurred.

  The predetermined time determination unit 130 calculates the predetermined time based on the battery liquid temperature detected by the battery state detection unit 110 and the voltage of the battery 200 when the engine is turned off or after a predetermined discharge. The internal state of the battery 200 can be determined from the output voltage output from the battery 200 when the engine is turned off or when a predetermined discharge occurs, and the battery liquid temperature. Hereinafter, the output voltage output from the battery 200 when the predetermined time is calculated, the predetermined time, and the relationship between the battery liquid temperature and the correction value will be described in detail.

  FIG. 5 is a diagram illustrating the relationship between the battery voltage and a predetermined time. As shown in FIG. 5, the predetermined time graph 700 indicates that the predetermined time is uniquely determined based on the voltage of the battery 200 when the engine is turned off or when there is a predetermined discharge. In addition, the predetermined time increases abruptly as the voltage increases. That is, it shows that it takes time until the internal state of the battery 200 is stabilized. The predetermined time graph 700 is a graph showing the relationship between the voltage of the battery 200 and the predetermined time when the battery liquid temperature is 25 [° C.]. When the battery liquid temperature changes, the time until the internal state of the battery 200 stabilizes also changes. Therefore, the predetermined time obtained from FIG. 5 is corrected by the battery liquid temperature after the engine is stopped or after a predetermined discharge has occurred.

  FIG. 6 is a diagram illustrating the relationship between the battery liquid temperature and the correction value. As shown in FIG. 6, the predetermined time correction graph 710 indicates that the correction value is uniquely determined based on the battery liquid temperature when the engine is turned off or when there is a predetermined discharge. For example, the correction value is 1 at 25 [° C.], and the predetermined time acquired in FIG. 5 can be used as it is until the internal state of the battery 200 is stabilized. When the temperature is lower than 25 [° C.], the time required for the internal state to become stable becomes longer, so the correction value becomes larger than 1. When the temperature is higher than 25 [° C.], the internal state can be stabilized quickly, so that the correction value is smaller than 1.

  By multiplying the predetermined time graph 700 and the value obtained from the predetermined time correction graph 710, the time until the internal state of the battery 200 is stabilized, that is, the predetermined time is determined.

Returning to FIG. 4, the processing function of master ECU 100 of the present embodiment will be described.
The time comparison unit 140 calculates the time after an operation to turn off the engine or after a predetermined discharge. Further, the predetermined time determination unit 130 compares the predetermined time with the predetermined time, and determines whether or not the predetermined time has elapsed. The battery deterioration determination unit 150 acquires the battery voltage when the starter 400 is started from the battery state detection unit 110 and the minimum voltage and maximum current are output. Further, the battery voltage and current before starting the starter 400 are acquired. Then, a voltage fluctuation width and a current fluctuation width are calculated from the acquired voltage value and current value, and a ratio between the voltage fluctuation width and the current fluctuation width is calculated. The theoretical ratio storage unit 160 stores a theoretical ratio table in which the theoretical ratio is associated with the battery liquid temperature. The battery deterioration determination unit 150 determines whether or not the battery 200 has deteriorated by reading the theoretical ratio corresponding to the battery liquid temperature from the theoretical ratio storage unit 160 and comparing it with the calculated ratio. When battery deterioration determining section 150 determines that the battery has deteriorated, it notifies using notification section 600. For example, the user is notified of the deterioration of the battery 200 by turning on a warning light indicating the battery deterioration provided on the panel of the automobile.

  FIG. 7 is a diagram showing how the voltage and current of the battery change when the starter is started. FIG. 7A is a waveform showing a change in voltage, and FIG. 7B is a waveform showing a change in current. It can be seen that the voltage value changes greatly when the starter 400 is started, and gradually returns to the voltage value before the starter 400 is started. Of the voltages when the starter 400 is being driven, the difference between the voltage at which the difference between before the starter 400 is started and the voltage before the starter 400 is started is defined as the voltage fluctuation width. Similarly, the current fluctuation width is defined as the difference between the current when the starter 400 is started and the current before the starter 400 is started and the current before the starter 400 is started.

  FIG. 8 is a diagram showing the relationship between the battery liquid temperature and the theoretical ratio. As shown in FIG. 8, the liquid temperature theoretical ratio graph 720 shows the relationship between the battery liquid temperature and the theoretical ratio between the voltage and current of the battery 200. The battery liquid temperature at the start of the starter 400 is indicated by a dotted line in the liquid temperature theoretical ratio graph 720. A circle 821 shown at the intersection of the dotted line and the graph shows the theoretical ratio at the start of the starter 400, and another circle 822 on the dotted line shows the current fluctuation width and voltage fluctuation width calculated by the battery deterioration determination unit 150. An example of the ratio is shown. A circle 822 indicates that the battery is deteriorated because the ratio is smaller than that of the circle 821.

  FIG. 9 is a diagram illustrating a data structure of a theoretical ratio table stored in the theoretical ratio storage unit. As shown in FIG. 9, the theoretical ratio table 161 has columns for battery liquid temperature and theoretical ratio. Information arranged in the vertical direction of each column is associated with each other. The battery liquid temperature is set in the battery liquid temperature column. In the example of FIG. 9, -40 to 40 are set at 20 ° C. intervals. In the theoretical ratio column, theoretical ratios from X1 to X5 are set. The values of X1 to X5 are X1 <X2 <X3 <X4 <X5.

The following processing is performed by the master ECU 100 having the above functions and data.
FIG. 10 is a flowchart illustrating a procedure of battery deterioration determination processing by the master ECU. In the following, the process illustrated in FIG. 10 will be described in order of step number. This process is repeatedly executed when the ignition switch is turned on.

  [Step S11] The battery state detection unit 110 determines whether or not a predetermined condition is satisfied. If the predetermined condition is satisfied, the process proceeds to step S12. If the predetermined condition is not satisfied, the process proceeds to step S24. The predetermined condition is a condition when the internal state of the battery 200 is stable and the deterioration determination of the battery 200 can be performed. The predetermined condition will be described later.

[Step S12] The battery state detection unit 110 detects the voltage value and current value of the battery 200 from the voltmeter 210 and ammeter 220 connected to the battery 200.
[Step S13] The battery state detection unit 110 determines whether the starter 400 has started. If the starter 400 is started, the process proceeds to step S14, and if not started, the process returns.

[Step S14] The battery state detection unit 110 detects the voltage value and current value of the battery 200.
[Step S15] The battery state detection unit 110 determines whether or not the voltage value detected in step S14 is the lowest voltage. If it is the lowest voltage, the process proceeds to step S16, and if it is not the lowest voltage, the process proceeds to step S14.

[Step S16] The battery state detection unit 110 stores the voltage value determined to be the lowest voltage.
[Step S17] The battery state detection unit 110 determines whether or not the current value detected in step S14 is the maximum current. If it is the maximum current, the process proceeds to step S18, and if it is not the maximum current, the process proceeds to step S14.

[Step S18] The battery state detection unit 110 stores the current value determined to be the maximum current.
[Step S19] The battery state detection unit 110 detects and stores the battery liquid temperature from the liquid thermometer 230 when the minimum voltage and the maximum current are determined.

  [Step S20] The battery state detection unit 110 determines whether the starter 400 has stopped. If it is determined that the starter 400 has stopped, the process proceeds to step S21. If it is determined that the starter 400 has not stopped, the process proceeds to step S14.

  [Step S21] The battery state detection unit 110 stores the value of the minimum voltage at the start time that is the minimum voltage value at the start time of the starter 400 and the maximum current value at the start time that is the maximum current value at the start time of the starter 400. The value of the current, the value of the voltage immediately before starting that is the voltage value immediately before starting the starter 400 acquired and stored in step S12 and the value of the current immediately before starting that is the current value immediately before starting the starter 400 are stored in the battery. Output to the degradation determination unit 150. When the battery deterioration determination unit 150 receives each voltage value and current value, the battery deterioration determination unit 150 calculates a fluctuation range of the voltage value and current value when the starter 400 is started. That is, the current fluctuation width which is the difference between the value of the current immediately before starting and the value of the maximum current at starting, and the voltage fluctuation width which is the difference between the value of the voltage immediately before starting and the value of the lowest voltage at starting are calculated. Then, a ratio between the calculated current fluctuation width and voltage fluctuation width is calculated.

[Step S <b> 22] The battery deterioration determination unit 150 acquires a theoretical ratio from the theoretical ratio storage unit 160 in accordance with the battery liquid temperature acquired from the battery state detection unit 110.
[Step S23] The battery deterioration determination unit 150 compares the calculated ratio between the current fluctuation width and the voltage fluctuation width with the theoretical ratio read from the theoretical ratio storage section 160 to determine whether or not the battery 200 has deteriorated. judge. And when it determines with the battery 200 having deteriorated, it alert | reports using the alerting | reporting part 600. FIG. For example, the user is notified of the deterioration of the battery 200 by turning on a warning light indicating the battery deterioration provided on the panel of the automobile.

  [Step S24] The master ECU 100 performs a stabilization process. The stabilization process is a process for stabilizing the internal state of the battery 200 whose internal state is not stable using the alternator 300. The stabilization process will be described later.

  FIG. 11 is a flowchart showing a procedure of predetermined condition processing by the master ECU of the present embodiment. In the following, the process illustrated in FIG. 11 will be described in order of step number. This process is repeatedly executed when the ignition switch is turned on.

  [Step S31] The battery state detection unit 110 determines whether or not an operation for turning off the engine has been performed. If an operation for turning off the engine is performed, the process proceeds to step S32. If an operation for turning off the engine is not performed, the process proceeds to step S35.

[Step S32] The battery state detection unit 110 clears the counter 120. The counter 120 starts counting again from the time when it is cleared.
[Step S33] The battery state detection unit 110 acquires the voltage value of the battery 200 from the voltmeter 210. Further, the battery liquid temperature is acquired from the liquid thermometer 230.

  [Step S34] When the predetermined time determination unit 130 acquires the voltage of the battery 200 and the battery liquid temperature when the battery state detection unit 110 performs an operation of turning off the engine or when the predetermined discharge occurs, the voltage and battery liquid are obtained. A predetermined time is determined from the temperature.

  [Step S35] The battery state detection unit 110 determines whether or not a predetermined discharge has occurred from the battery 200. If there is a predetermined discharge, the process proceeds to step S32. If there is no predetermined discharge, the process proceeds to step S36. The predetermined discharge means that a current of a certain value or more flows. For example, the ECU of the security system is activated when security reacts to the vehicle and flows to supply power to the ECU. Current.

  [Step S36] The time comparison unit 140 calculates the time from when the engine is turned off or after a predetermined discharge has occurred from the value of the counter 120, and compares it with the predetermined time determined by the predetermined time determination unit 130. Do. If there has been an operation to turn off the engine, or if a predetermined time has passed since the occurrence of a predetermined discharge, the process proceeds to step S37, and if not, the process proceeds to step S38.

  [Step S37] The time comparison unit 140 sets a flag indicating that a predetermined condition is satisfied. For example, “1” is set when a predetermined condition is satisfied in a predetermined area of the RAM 101c.

  [Step S38] The time comparison unit 140 indicates that the predetermined condition is not satisfied. For example, “0” is set when a predetermined condition is not satisfied in a predetermined area of the RAM 101c. The battery state detection unit 110 determines whether or not the predetermined condition is satisfied by referring to the numerical value set in the predetermined area of the RAM 101c in step S11 of FIG.

  By performing such a process, the battery deterioration determination is made erroneously when the internal state of the battery 200 is not stable, such as immediately after the engine is turned off or after a predetermined discharge. It can be prevented that the determination result is obtained.

  FIG. 12 is a flowchart showing the procedure of the stabilization process by the master ECU. In the following, the process illustrated in FIG. 12 will be described in order of step number. This process is repeatedly executed when the ignition switch is turned on.

  [Step S41] The battery state detection unit 110 determines whether or not the engine has started. If the engine has started, the process proceeds to step S42. If the engine has not started, the process ends.

[Step S42] The battery state detection unit 110 acquires the voltage value of the battery 200 from the voltmeter 210 and acquires the current value of the battery 200 from the ammeter 220.
[Step S43] The battery state detection unit 110 determines an output value output by the alternator 300 from the acquired current value and voltage value. The output value of alternator 300 is determined from the target charging voltage of battery 200 and the voltage value and current value detected by battery state detection unit 110.

[Step S44] The battery state detection unit 110 instructs the alternator 300 to output the determined output value.
[Step S45] The battery state detection unit 110 acquires the current value of the battery 200 from the ammeter 220. Then, it is determined whether or not the acquired current value is 0 [A]. If the current value is 0 [A], the process proceeds to step S46. If the current value is not 0 [A], the process proceeds to step S42.

  [Step S46] The master ECU 100 determines whether or not the internal state of the battery 200 is stable. If the internal state is stable, the process proceeds to step S47. If the internal state is not stable, the process proceeds to step S42. Note that the determination of whether or not the internal state of the battery 200 is stable is realized by performing the predetermined condition processing shown in FIG. At this time, the predetermined time determination unit 130 determines the predetermined time from the voltage of the battery 200 and the battery liquid temperature when it is determined that the current value in step S45 is within the predetermined range.

  [Step S47] The battery state detection unit 110 outputs a start instruction signal so that the battery 200 starts to a device that discharges a relatively large current. For example, a start instruction signal is output to the compressor of the air conditioner. This discharge is compared with a compressor of an air conditioner as well as obtaining a voltage and current fluctuation range of the battery 200 to determine whether or not the battery 200 has deteriorated when the starter 400 is driven. This is done in order to intentionally create the voltage and current fluctuations of the battery 200, such as when the starter 400 is driven, by starting a device that requires a large amount of power.

  [Step S48] The battery deterioration determination unit 150 performs battery deterioration determination using a deliberately created fluctuation width. The battery deterioration determination performs the same process as the process from step S14 to step S19 shown in FIG.

  By performing such a process, the output of the alternator 300 and the power consumption of the auxiliary machine coincide. That is, since free discharge from the battery 200 is eliminated, it is possible to reproduce a state in which the auxiliary machine is not used. Therefore, it is possible to determine the deterioration of the battery 200 with the engine running.

  Note that although it has been described that it is determined whether or not the operation for turning off the engine has been performed in step S31 of FIG. 11, the operation is not limited to the operation for turning off the engine as long as the discharge from the battery 200 is 0 [A]. Further, the discharge is not limited to 0 [A], but may have a certain width.

  The ratio of the voltage fluctuation width and the current fluctuation width at the time of starting the engine is calculated, and the calculated ratio is compared with the theoretical ratio at which the battery 200 stored in advance in the theoretical ratio storage unit 160 is normal. Therefore, it is possible to properly determine the deterioration of the battery 200 without being affected even if there is an abnormality in an auxiliary machine to which the power of the battery 200 is supplied.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The battery deterioration determination device of the present embodiment is the same as the configuration shown in the first embodiment, except that navigation is connected to the master ECU. For this reason, about the component similar to the said 1st Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably.

  FIG. 13 is a diagram illustrating processing functions of the master ECU according to the present embodiment. As shown in FIG. 13, the master ECU 2100 includes a battery state detection unit 110, a predetermined time determination unit 130, a time comparison unit 140, a battery deterioration determination unit 150, a theoretical ratio storage unit 160, and a time detection unit 2170. . In addition, a notification unit 600 and a navigation 800 are connected to the master ECU 2100.

  The battery state detection unit 110 detects a voltage value, a current value, and a battery liquid temperature from the voltmeter 210, the ammeter 220, and the liquid thermometer 230 connected to the battery 200. The detected information is used to determine whether or not the battery 200 has deteriorated. It is known that the internal resistance of the battery 200 increases when it deteriorates. Since (voltage value) = (current value) × (resistance value), the ratio of the voltage fluctuation width to the current fluctuation width is obtained, and compared with the theoretical ratio stored in the theoretical ratio storage unit 160, the battery 200 is deteriorated. It can be determined whether or not.

  The time detection unit 2170 reads the time from the navigation 800 in order to measure the elapsed time for determining whether or not the internal state of the battery 200 is stable. The elapsed time is the time from when the engine is turned off or when a predetermined discharge occurs until the master ECU 2100 is activated. Therefore, the time detection unit 2170 reads the time when there is an operation to turn off the engine or when there is a predetermined discharge from the navigation 800 and stores it as time 1. Further, the time when the master ECU 2100 is activated is read from the navigation 800 and stored as time 2. Then, the time elapsed from time 1 and time 2 is calculated.

  The predetermined time determination unit 130 calculates the predetermined time based on the battery liquid temperature detected by the battery state detection unit 110 and the voltage of the battery 200 when the engine is turned off or when there is a predetermined discharge. The internal state of the battery 200 can be determined from the output voltage output from the battery 200 when the engine is turned off or when a predetermined discharge occurs, and the battery liquid temperature.

  When the time comparison unit 140 receives the elapsed time calculated by the time detection unit 2170, the time comparison unit 140 compares the elapsed time with the predetermined time determined by the predetermined time determination unit 130, and determines whether the time has elapsed from the predetermined time. The battery deterioration determination unit 150 acquires the battery voltage when the starter 400 is started from the battery state detection unit 110 and the minimum voltage and maximum current are output. Further, the battery voltage and current before starting the starter 400 are acquired. Then, a voltage fluctuation width and a current fluctuation width are calculated from the acquired voltage value and current value, and a ratio between the voltage fluctuation width and the current fluctuation width is calculated. The theoretical ratio storage unit 160 stores a theoretical ratio table in which the theoretical ratio is associated with the battery liquid temperature. The battery deterioration determination unit 150 determines whether or not the battery 200 has deteriorated by reading the theoretical ratio corresponding to the battery liquid temperature from the theoretical ratio storage unit 160 and comparing it with the calculated ratio. When battery deterioration determining section 150 determines that the battery has deteriorated, it notifies using notification section 600. For example, the user is notified of the deterioration of the battery 200 by turning on a warning light indicating the battery deterioration provided on the panel of the automobile.

  FIG. 14 is a flowchart showing a procedure of predetermined condition processing by the master ECU of the present embodiment. In the following, the process illustrated in FIG. 14 will be described in order of step number. This process is repeatedly executed when the ignition switch is turned on.

  [Step S51] The battery state detection unit 110 determines whether or not an operation for turning off the engine has been performed. If an operation for turning off the engine is performed, the process proceeds to step S52. If an operation for turning off the engine is not performed, the process proceeds to step S55.

  [Step S52] The battery state detection unit 110 notifies the time detection unit 2170 that an operation for turning off the engine has been performed or a predetermined discharge has occurred. Time detector 2170 reads the time from navigation 800 and stores it as time 1.

[Step S53] The battery state detection unit 110 acquires the voltage value of the battery 200 from the voltmeter 210. Further, the battery liquid temperature is acquired from the liquid thermometer 230.
[Step S54] When the predetermined time determination unit 130 acquires the voltage of the battery 200 and the battery liquid temperature when the battery state detection unit 110 operates to turn off the engine or when the predetermined discharge occurs, the voltage and the battery liquid are obtained. A predetermined time is determined from the temperature.

  [Step S55] The battery state detection unit 110 determines whether or not a predetermined discharge has occurred from the battery 200. If there is a predetermined discharge, the process proceeds to step S52. If there is no predetermined discharge, the process proceeds to step S56. The predetermined discharge means that a current of a certain value or more flows. For example, the ECU of the security system is activated when security reacts to the vehicle and flows to supply power to the ECU. Current.

  [Step S56] It is determined whether the master ECU 2100 is activated. If activated, the process proceeds to step S57. If not activated, the process proceeds to step S51.

[Step S57] When the master ECU 2100 is activated, the time detection unit 2170 reads the time from the navigation 800 and stores it as time 2.
[Step S58] The time detector 2170 calculates the elapsed time from time 1 and time 2.

  [Step S59] The time comparison unit 140 receives a time from the time detection unit 2170 when there is an operation to turn off the engine or a predetermined discharge, and compares it with the predetermined time determined by the predetermined time determination unit 130. . When there is an operation to turn off the engine, or when a predetermined time has passed since a predetermined discharge, the process proceeds to step S60, and when the predetermined time has not elapsed, the process proceeds to step S61.

  [Step S60] The time comparison unit 140 sets a flag indicating that the predetermined condition is satisfied. For example, “1” is set when a predetermined condition is satisfied in a predetermined area of the RAM 101c.

[Step S61] The time comparison unit 140 indicates that the predetermined condition is not satisfied. For example, “0” is set when a predetermined condition is not satisfied in a predetermined area of the RAM 101c.
By performing such processing, the battery deterioration determination is performed when the internal state of the battery 200 is not stable, such as immediately after the engine is turned off or immediately after a predetermined discharge, resulting in a result. It is possible to prevent erroneous determination. Further, when the engine is turned off, or when a predetermined discharge occurs, and when the master ECU 2100 is activated, the elapsed time is calculated by receiving the time from an auxiliary machine having a time means connected in advance. Therefore, it is not necessary to always start the counter as in the case of measuring the elapsed time using the counter, and the elapsed time can be calculated without further cost.

  Although the description has been given that the time is read from the navigation 800, the time may be read from any auxiliary device as long as the time is not limited to the navigation 800 but is from an auxiliary device having a clock mounted in advance in the vehicle. The same effect as when the time is read from 800 is obtained.

It is a conceptual diagram of the invention applied to this Embodiment. It is a figure which shows the system configuration example which concerns on this Embodiment. It is a figure which shows the hardware structural example of master ECU used for this Embodiment. It is a figure which shows the processing function of master ECU of this Embodiment. It is a figure which shows the relationship between the voltage of a battery, and predetermined time. It is a figure which shows the relationship between battery liquid temperature and a correction value. It is the figure which showed the mode of the change of the voltage and electric current of a battery when starting a starter. It is a figure which shows the relationship between battery liquid temperature and theoretical ratio. It is a figure which shows the data structure of the theoretical ratio table memorize | stored in the theoretical ratio memory | storage part. It is a flowchart which shows the procedure of the battery deterioration determination process by master ECU. It is a flowchart which shows the procedure of the predetermined condition process by master ECU of this Embodiment. It is a flowchart which shows the procedure of the stable process by master ECU. It is a figure which shows the processing function of master ECU of this Embodiment. It is a flowchart which shows the procedure of the predetermined condition process by master ECU of this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery deterioration determination apparatus 1a Voltage / current detection means 1b Internal resistance calculation means 1c Internal resistance storage means 1d Battery deterioration determination means 2 Battery

Claims (9)

In a battery deterioration determination device that determines deterioration of a vehicle battery,
Voltage detecting means for detecting a voltage fluctuation width of the battery at the time of starting the engine;
Current detecting means for detecting a current fluctuation width of the battery at the time of starting the engine;
An internal resistance calculating means for calculating an actual internal resistance of the battery from the voltage swing width and the current swing width;
Internal resistance storage means in which internal resistance for determination that the battery is normal is stored;
Battery deterioration determination means for determining deterioration of the battery by the actual internal resistance and the determination internal resistance;
A battery deterioration determination device characterized by comprising: A temperature detecting means for detecting a temperature at the time of starting the engine;
The battery deterioration determination device according to claim 1, wherein the battery deterioration determination unit determines deterioration of the battery based on the actual internal resistance and the determination internal resistance corresponding to the temperature. Stability determination means for determining whether or not the internal state of the battery is stable when the engine is started;
When the stability determining means determines that the internal state of the battery is not stable, the stabilizing means for executing the battery stabilization process;
The battery deterioration determination device according to claim 1, wherein:   4. The battery deterioration determination according to claim 3, wherein the stability determination means determines whether or not the battery is stable depending on whether or not a time elapsed since the engine was stopped exceeds a predetermined time. apparatus.   The stability determining means determines whether the battery is stable depending on whether or not a time elapsed from the predetermined discharge exceeds a predetermined time when the battery has a predetermined discharge after the engine is stopped. The battery deterioration determination apparatus according to claim 4.   5. The battery deterioration determination device according to claim 4, wherein the stability determination means determines the predetermined time based on an output voltage of the battery when the engine is stopped.   5. The battery deterioration determination device according to claim 4, wherein the stability determination unit corrects the predetermined time based on a temperature of the battery when the engine is stopped.   4. The battery deterioration determination device according to claim 3, wherein the stabilization means controls the alternator so that the discharge current of the battery becomes a predetermined value or less, thereby stabilizing the internal state of the battery. In a battery deterioration determination method for determining deterioration of a vehicle battery,
A voltage detecting means for detecting a voltage fluctuation width of the battery at the time of starting the engine;
A current detecting means for detecting a current fluctuation width of the battery at the time of starting the engine;
An internal resistance calculating means calculating an actual internal resistance of the battery from the voltage swing width and the current swing width;
An internal resistance storage means for storing an internal resistance for determination that the battery is normal;
A step of determining deterioration of the battery by the actual internal resistance and the determination internal resistance;
The battery deterioration determination method characterized by including.

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