JP2019039825A - Battery state diagnosing device and battery state diagnosis method - Google Patents

Abstract

To provide a battery state diagnosing device and a battery state diagnosis method with which it is possible to suppress the occurrence of misdetection of a second peak due to the effect of environment noise and detect the second peak with high accuracy.SOLUTION: Sixteen (N, natural number) of latest moving average voltage values AV(moving average value, A) in measured voltage values PV(measured value, P) of voltage value V are calculated. By comparing with the immediately preceding moving average voltage value AV(moving average value, A), a rise "1" or a fall "0" is successively determined, and a change point Tc of time where the determination result turns from the rise "1" to the fall "0" is detected, with a second peak Pdetected from this change point Tc of time. The state of a battery B is diagnosed on the basis of a measured voltage value PVat this second peak P.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a battery state diagnosis device and a battery state diagnosis method, and more particularly, in a battery of a vehicle equipped with an engine, the charge state or deterioration state is diagnosed based on a voltage value or a current value when the engine is cranked. The present invention relates to a battery state diagnosis device and a battery state diagnosis method.

  In recent years, in order to diagnose the state of charge or deterioration of a battery mounted on a vehicle, it is widely performed to attach a current sensor, a voltage sensor, or the like to the battery to detect the current value or voltage value of the battery.

  In particular, in order to diagnose the state of the battery, a voltage value and a current value when the engine is cranked are generally used. However, during cranking, the current flowing through the starter motor is an inrush current immediately after that, and a large current flows. Thereafter, when the inrush current converges, a current corresponding to the rotation of the starter motor flows. For this reason, the voltage value and the current value when cranking are steep waveforms.

Here, in order to improve the reliability of diagnosis, the minimum value of the voltage value after the inrush current has converged and the current value at that time are detected, and the state of the battery is diagnosed based on the detection result. For example, as shown in FIG. 4, the voltage value indicated by reference numeral P ₂ indicates the minimum peak voltage value after the inrush current has converged. That is, the voltage value P ₂ is a minimum peak of the driving period of the starter motor before the engine starts. State diagnosis of the battery is performed based on the voltage value P _2.
Incidentally, the voltage value P ₂ is also referred to as "second peak" so when the first peak due to the inrush current hits the second peak. Unless otherwise stated in this specification, also referred to the voltage value P ₂ than the "second peak". FIG. 4 is a graph showing a waveform of a voltage measurement value during engine cranking.

  In order to detect the battery state by detecting the peak, current detection means (current sensor) for detecting the current value of the battery current, and after the inrush current flows to the starter motor based on this current value, Inflection point detection means for detecting the first inflection point of the current after the inrush current flows based on the extreme value detection diagnosis for detecting the first extreme value of the current and the amount of change of the current value per predetermined time If the timing at which the extreme value and the inflection point are detected is separated by a predetermined time or more, the inflection point is selected. Otherwise, either the extreme value or the inflection point is selected. Is selected as a starting current (see Patent Document 1).

  In addition, it has a voltage sensor that detects the output voltage of the battery, and a processing unit that detects the state of the battery based on the detection voltage of the voltage sensor, and this processing unit is used when engine cranking is performed. The number of cranking of the engine is detected based on the waveform within one waveform period or less including any one peak included in the waveform of the detection voltage detected by the voltage sensor, and based on the cranking rotation speed. A device that diagnoses the state of a battery is also known (see Patent Document 2).

JP 2013-193620 A JP 2007-83965 A

  By the way, in the battery state diagnosis apparatus as shown in the above-mentioned Patent Documents 1 and 2, a microcomputer (control circuit, processing unit) is usually mounted, and the microcomputer controls the voltage sensor and the current sensor at a predetermined sampling period. The current value and the voltage value are discretely captured and processed as measured values (sample data). Specifically, in order to detect the peak at the time of cranking, the measured value of the predetermined time from the fall time of the voltage value in the voltage waveform at the time of cranking is first stored and stored in a storage unit such as a memory in chronological order. To do. And based on the measured value memorize | stored and hold | maintained at the memory | storage part, a microcomputer searches for a peak.

  However, simply detecting the second lowest voltage value is insufficient to detect the second peak measurement value from the large measurement value, and the first inrush current converges. After that, it is necessary to detect the peak.

  In Patent Document 1, the first inflection point of the current value is calculated to detect the second peak. Specifically, Patent Document 1 sequentially calculates a difference between a current measurement value (current sample data) and a previous measurement value (sample data before one sampling period), and the calculation result increases (increases) or The second peak was simply detected depending on whether it was falling (decreasing). However, the vehicle has a lot of environmental noise generated by radio noise, internal devices, a rotation drive mechanism, and the like. For this reason, the environmental noise may be erroneously detected by a detection unit such as a voltage sensor or a current sensor, and thereby the second peak may be erroneously detected due to the influence of the environmental noise.

  The present invention has been made in view of the above-described circumstances, and an object thereof is a battery state capable of suppressing the occurrence of false detection of the second peak due to the influence of environmental noise and accurately detecting the second peak. A diagnostic device and a battery state diagnostic method are provided.

In order to achieve the above-described object, a battery state diagnosis apparatus and a battery state diagnosis method according to the present invention are characterized by the following (1).
(1)
A battery state diagnosis device for diagnosing a battery state when an engine mounted on a vehicle is cranked,
A storage unit that stores and holds the voltage value or current value of the battery in a time-series order t (t = 1, 2,..., T) as a measurement value P at a predetermined sampling period;
For each of the measured values P _t stored and held in the storage unit, the latest N (N is a natural number of 2 or more) measured values (P _t , P _t−1 , P _t−2 ,..., P calculating a _{t-N + 1)} moving average value a _t of said moving relative to each average value a _t, sequentially determines whether raising or lowering of the as compared to the moving average value a _t-1 immediately preceding, the When the measurement value _Pt is a voltage value, the determination result detects a change time Tc that changes from rising to falling, and when the measurement value _Pt is a current value, the change time Tc changes from falling to rising. In the moving average value (A _Tc ,..., A _Te ) until the ranking end time Te, the minimum is obtained when the measured value P _t is a voltage value, and the measured value P _t is a current value. the moving average value a _t at which the maximum and the second peak, put the second peak A control unit for diagnosing the condition of the battery based on the measured value P _t or the moving average value A _t that,
A battery state diagnosis apparatus comprising:

According to the configuration of the battery condition diagnosis apparatus of the above (1), and detects the second peak to calculate the most recent N mobile average value A _t the measured value P _t of the voltage value or current value, environmental noise Therefore, it is possible to suppress the occurrence of false detection of the second peak due to the influence of environmental noise. Further, in the state where the high-frequency component is removed in this manner, ascending or descending is sequentially determined as compared with the immediately preceding moving average value At _-1, and when the measured value P _t is a voltage value, When the measured value P is a current value from the rise, the change time Tc from the fall to the rise is detected, and the second peak is detected from the change time Tc. Thereby, a 2nd peak can be detected reliably and the precision of a battery state diagnosis can be improved.

Battery condition diagnosis apparatus of the present invention, and according to the battery condition diagnosis method, and detects the second peak to calculate the most recent N mobile average value A _t the measured value P _t of the voltage value or current value, It is possible to remove high-frequency components due to environmental noise and suppress the occurrence of false detection of the second peak due to the influence of environmental noise. Further, in the state where the high-frequency component is removed in this manner, ascending or descending is sequentially determined as compared with the immediately preceding moving average value At _-1, and when the measured value P _t is a voltage value, When the measured value P is a current value from the rise, the change time Tc from the fall to the rise is detected, and the second peak is detected from the change time Tc. Thereby, a 2nd peak can be detected reliably and the precision of a battery state diagnosis can be improved.

  The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through a mode for carrying out the invention described below (hereinafter referred to as “embodiment”) with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a schematic configuration of the battery state diagnosis apparatus according to the first embodiment of the present invention. FIG. 2 is a functional block diagram functionally illustrating the software configuration of the control unit shown in FIG. FIG. 3 is a flowchart for explaining processing performed by the control unit shown in FIG. FIG. 4 is a graph showing a waveform of a voltage measurement value during engine cranking. FIG. 5 is a graph showing a waveform of a current measurement value during engine cranking. FIG. 6 is a graph showing the moving average waveform of the voltage measurement value shown in FIG. 4 together with the rising or falling change state in the waveform. FIG. 7 is a functional block diagram functionally illustrating the software configuration of the control unit according to the second embodiment of the present invention. FIG. 8 is a flowchart for explaining processing performed by the control unit shown in FIG.

  A plurality of specific embodiments relating to the battery state diagnosis apparatus and the battery state diagnosis method of the present invention will be described below with reference to the drawings.

  Note that the “unit” in the present embodiment is not limited to a physical configuration simply realized by hardware, but also includes a function realized by the configuration realized by software such as a program. Further, the functions of one configuration may be realized by two or more physical configurations, or the functions of two or more configurations may be realized by, for example, one physical configuration.

(First embodiment)
With reference to FIGS. 1-6, 1st Embodiment of the battery condition diagnostic apparatus and battery condition diagnostic method which concern on this invention is described.
In the present embodiment, the second peak is detected based on the voltage value and the voltage measurement value (measurement value). A case based on a current value and a current measurement value (measurement value) will be described in the second embodiment.

<Configuration of battery condition diagnosis device>
First, with reference to FIG. 1, the structure of the battery state diagnosis apparatus 10 of this embodiment is demonstrated. FIG. 1 is a block diagram illustrating a schematic configuration of a battery state diagnosis device 10 of the present embodiment.

  As shown in FIG. 1, the battery state diagnosis device 10 of the present embodiment is attached to a battery B mounted on an automobile (vehicle), and when the engine E mounted on the automobile is cranked, It diagnoses the deterioration state. The battery state diagnosis device 10 includes a voltage sensor 11, a current sensor 12, an alarm 13, a memory (storage unit) 20, and a microcomputer (control unit) 30.

  Battery B is a liquid lead acid battery containing lead dioxide as the positive electrode, spongy lead as the negative electrode, and dilute sulfuric acid as the electrolyte. Battery B is charged by an alternator (not shown) that has a negative electrode grounded and is connected to the drive unit of engine E. The battery B is constituted by a DC motor, supplies electric power to the starter motor S connected to the engine E, and rotates the starter motor S. The starter motor S cranks the engine E and starts the engine E. During this cranking, an inrush current flows through the battery B. When the inrush current converges, a current corresponding to the rotation of the starter motor S flows through the battery B.

The voltage sensor 11 includes an IC (Integrated Circuit) including an amplifier circuit as hardware, detects a terminal voltage of the battery B, and outputs a voltage value V as a detection result to the microcomputer 30. Similarly, the current sensor 12 includes an IC or the like, detects a current flowing through the battery B, and outputs a current value I as a detection result to the microcomputer 30.
The current sensor 12 further includes, for example, a resistance portion (not shown) whose resistance value is known, and based on the resistance value of the resistance portion and the voltage value V of the voltage sensor, the current flowing through the battery B according to Ohm's law. You may comprise so that it may detect.

The alarm 13 is composed of a normal red LED light, and is lit according to an instruction from the control unit 30. This lighting informs the driver of the state of the battery B.
Note that the alarm 13 may be arranged on the meter panel of the automobile.

The memory 20 has a measurement data storage area 21 and a parameter storage area 22. The memory 20 stores the voltage value V of the voltage sensor 11 and the current value I of the current sensor 12 in the measurement data storage area 21, the voltage measurement value PV _t (measurement value, P) and the current measurement value PI _t (measurement value, P) is stored and held in time series order t (t = 1, 2,..., T). Further, the memory 20 stores and holds a current threshold value (described later) TH for detecting a cranking end time Te by a peak detecting unit (described later) 36 of the microcomputer 30 in the parameter storage area 22.

The capacity of the memory 20 is larger than that of the memory circuit (not shown) of the microcomputer 30 so that these measured values PV _t and PI _t can be stored. The voltage value V of the voltage sensor 11 and the current value I of the current sensor 12 are captured at a predetermined sampling period by a sample capturing unit (described later) 31 of the microcomputer 30. Then, the voltage value V of the voltage sensor 11 and the current value I of the current sensor 12 are set as the voltage measurement value PV _t and the current measurement value PI _{t in} the measurement data storage area 21 of the memory 20 according to the instruction of the sample take-in unit 31. Retained.

  The microcomputer 30 is configured by a normal minicomputer system having hardware, not shown, an arithmetic circuit, an interface circuit, a memory circuit, a communication circuit, and the like, and functions as a control unit of the battery state diagnosis apparatus 10.

<Microcomputer configuration>
Next, functions related to the software configuration of the microcomputer 30 will be described with reference to FIG. FIG. 2 is a functional block diagram functionally illustrating the configuration of the microcomputer 30.

As shown in FIG. 2, the microcomputer 30 of the present embodiment includes a sample acquisition unit 31, a moving average calculation unit 32, an up / down determination unit 33, a continuous determination unit 34, a change detection unit 35, and a peak detection unit. 36 and a state diagnosis unit 37.
In the present embodiment, these portions are stored as programs in the memory circuit of the microcomputer 30, and are appropriately read out and executed by the arithmetic circuit of the microcomputer 30.

The sample take-in unit 31 converts the voltage value V of the voltage sensor 11 and the current value I of the current sensor 12 into the voltage measurement value PV _t and the current measurement value PI _t (t = 1) at a predetermined sampling cycle through the interface circuit of the microcomputer 30. , 2,..., T) in time sequence t. Further, the sample take-in unit 31 outputs the taken measurement values PV _t and PI _t to the memory 20 and stores them in the measurement data storage area 21 of the memory 20 in association with each other in time series.

Moving average calculation section 32 reads the voltage measurement value PV _t stored in the memory 20, for each the voltage measurement value PV _t, last N (N is a natural number of 2 or more, in this embodiment of the "16" Value) The voltage moving average value AV _t (moving average value, A _t ) of the voltage measurement values PV _t , PV _t−1 , PV _t−2 ,..., PV _t−15 is calculated in time series order t. . Moving average calculation section 32 outputs the voltage moving average value AV _t is the calculation result to the upper and lower determination unit 33 and the peak detector 36.

Vertical determination unit 33 reads a voltage moving average AV _t of the moving average calculation section 32, to the voltage moving average value AV _t respectively, increases as compared with the voltage moving average AV _t-1 of the immediately preceding (increase) Alternatively, it is determined selectively in time series order t whether it is descending (decreasing). At this time, the up / down determination unit 33 substitutes a value of “1” for an increase and a value of “0” for a decrease, and quantifies the determination result as a change direction (variable) CD _t (FIG. 6). reference). The up / down determination unit 33 outputs the change direction CD _t as the determination result to the continuation determination unit 34 and the change detection unit 35.

The continuity determination unit 34 reads the change direction CD _t of the up / down determination unit 33 and sequentially counts the number of consecutive “1” rises in the change direction CD _t in time series order t. The continuation determination unit 34 determines whether or not the counted number of consecutive “1” increases is M (M is a natural number of 2 or more, in the present embodiment, a value of “10”) or more. When it is determined that the number of consecutive “1” increases is 10 or more, the continuity determination unit determines that the voltage moving average value _AVt is continuously increasing (an increasing condition). As a result of the determination, the continuation determination unit 34 substitutes the value “1” for the determination flag (setting variable) F and changes the value from “0” to “1”. The continuation determination unit 34 outputs the confirmation flag F to the change detection unit 35 as a detection start signal.

The change detection unit 35 reads the confirmation flag F of the continuation determination unit 34, signals that the confirmation flag F has become “1”, and starts detection from that point. That is, the change detection unit 35 also reads the change direction CD _t of the up / down determination unit 33 at the same time, and the change direction CD _t increases from “1” to “0” after the confirmation flag F becomes “1”. The change time Tc, which is the moment of turning to, is detected in chronological order t (see FIG. 6). Then, the change detection unit 35 outputs the value of the change time Tc that is the detection result to the peak detection unit 36.

The peak detection unit 36 reads the change time Tc of the change detection unit 35, the voltage moving average value AV _{t of} the moving average calculation unit 32, the current measurement value PI _{t of} the memory, and the current threshold value TH of the memory 20. Then, the peak detection unit 36 detects the voltage moving average value AV _t at the time point that is the minimum with respect to the voltage moving average value AV _t of the moving average calculation unit 32 in the time series order t with the change time Tc as the detection start time. start.

The peak detection unit 36 sequentially determines whether or not the current measurement value PI _t is less than the current threshold value TH in parallel with this detection, the moment when the current measured value PI _t is equal to or less than the current threshold value TH It is detected as the cranking end time Te (see FIG. 6). That is, the peak detection unit 36 detects the voltage moving average value AV _t at the minimum time in the voltage moving average values AV _Tc ,..., AV _Te from the change time Tc to the cranking end time Te. setting the voltage moving average value AV _t as the second peak _{P 2.} The peak detector 36 outputs the second information peak P ₂ in the state diagnosis unit 37.

The state diagnosis unit 37 diagnoses the state of the battery B based on the voltage measurement value PV _t at the second peak P ₂ detected by the peak detection unit 36. Specifically, condition diagnosis unit 37, when the voltage measurement value PV _t at the second peak P ₂ is equal to or less than a predetermined threshold set in advance, lighting an alarm 13 as a battery B is degraded Let me warn you. Further, the state diagnosis unit 37 outputs the diagnosis result to an upstream device (not shown).
In the present embodiment, the diagnosis of the battery B is performed based on the voltage measurement value PV _t , but instead, the voltage moving average value AV _{t at} the second peak P ₂ , or the current measurement value PI _t or the current movement is determined. it may be performed by the average value AI _t.

<Microcomputer processing procedure, battery status diagnosis method>
Next, the operation of the battery state diagnosis apparatus 10 according to the present embodiment, particularly the processing procedure of the microcomputer 30 and the battery state diagnosis method will be described with reference to FIGS. FIG. 3 is a flowchart for explaining processing performed by the microcomputer (control unit) 30. Figure 4 is a graph showing a waveform of a voltage measurement value PV _t during cranking of the engine E. FIG. 5 is a graph showing a waveform of the current measurement value PI _t when the engine E is cranked. FIG. 6 is a graph showing a waveform of the voltage moving average value AV _t (moving average waveform of the voltage measurement value PV _t ) together with a change direction CD _t (upward or downward change state) in the waveform.

As shown in FIG. 3, first, in step S <b> 11, the voltage value V and the current value I of the battery B are detected by the voltage sensor 11 and the current sensor 12 when the engine E is cranked. The voltage value V and the current value I are input to the sample acquisition unit 31 of the microcomputer 30 and are acquired as the voltage measurement value PV _t and the current measurement value PI _t at a predetermined sampling period.

In step S <b> 12, the voltage measurement value PV _t and the current measurement value PI _t periodically taken by the sample taking unit 31 are stored and held in the measurement data storage area 21 of the memory 20 in time series order t. At this time, the voltage measurement value PV _t and the current measurement value PI _t are stored in association with each other in time series.

As shown in FIGS. 4 and 5, the voltage measurement value PV _t and the current measurement value PI _t are waveforms in which high-frequency components due to environmental noise are superimposed in a state where they are stored in the memory 20. Yes. Upon detecting the second peak P ₂ in this state, there is a possibility of erroneous detection due to the influence of the high frequency components. Therefore, in the present embodiment, in order to remove high frequency components from the voltage measurement value PV _t, performs step S13.

Returning to FIG. 3, the description will be continued. In step S13, the moving average calculation section 32 reads the voltage measurement value PV _t from the memory 20, the voltage measurement value PV _t last 16 voltage measurement value _PV t for each, PV _t-1, PV _{t- 2} ,..., PV _t−15 , the voltage moving average value AV _t is calculated in chronological order t. This calculation, the moving average calculation section 32 removes a high frequency component of the voltage measurement value PV _t.

In step S14, the up / down determination unit 33 determines whether the voltage moving average value AV _t calculated in step S13 is an increase “1” or a decrease “0” compared to the immediately preceding voltage moving average value AV _t−1. Each determination is made selectively in time series order t, and this determination result is digitized as the change direction CD _t . That is, the upper and lower determination unit 33, a voltage moving average AV _t, increase when increased compared to the voltage moving average AV _t-1 immediately preceding a "1", when it is reduced down to "0" as sequentially determines the change of the increase or decrease in voltage moving average AV _t.

Referring now to FIG. 6, the variation of the voltage moving average AV _t, the changing direction CD _t voltage moving average AV _t, the relationship will be described.

As shown by the solid line in FIG. 6, when the cranking of the engine E inrush current flows immediately thereafter, the voltage moving average AV _t, after sharply lowered correspondingly increases gradually. When the starter motor S is driven to rotate, the voltage moving average AV _t varies periodically. Further, after starting the engine E, the voltage moving average AV _t, in a steady state once risen.
However, the voltage moving average AV _t even in the steady state is varied periodically, the amplitude is small.

Then, as shown by the dotted line in FIG. 6, the change direction CD _t of the voltage moving average value AV _t corresponding to the voltage moving average value AV _t changing in this way is immediately after the change in the inrush current. An increase “1” is indicated, but a sharp decrease is indicated by a decrease “0”. Thereafter, the change direction CD _t shows a state of rising “1” for a while until the inrush current converges. The change direction CD _t periodically repeats the rising “1” or the falling “0” when the starter motor S is driven to rotate. In consideration of such variation characteristics, in the present embodiment, in order to detect the variation time Tc as the variation start time by the starter motor S, step S15 to step S18 are sequentially performed.

Returning to FIG. 3 again, the description will be continued. In step S15, the continuation determination unit 34 sequentially counts the number of consecutive “1” increases in the change direction CD _t in step S14 in time series order t. In step S <b> 16, the continuation determination unit 34 determines whether the counted number of times of increase “1” is 10 or more.

  If the result of determination in step S16 is that the number of consecutive times is less than 10 or if the count has fallen to “0” during the count up to 10 times, the result of step S16 is NO and step S15 is entered. Returning, the continuation determination unit 34 continues the count of the increase “1” or starts counting again from the beginning.

On the other hand, as a result of the determination in step S16, if the count of the continuous “1” increase is 10 or more, the process proceeds to step S17 with YES in step S16. In step S17, continuity judgment section 34 determines the rising status as a situation where the voltage moving average AV _t continues to increase. As a result of the determination, the continuation determination unit 34 assigns “1” to the determination flag F, and outputs a detection start signal to the change detection unit 35.

In step S <b> 18, the change detection unit 35 starts detection from that time with a signal that the confirmation flag F has been changed to “1” by the continuation determination unit 34. That is, the change detection unit 35 changes the time Tc at which the change direction CD _{t in} step S14 changes from rising “1” to falling “0” in the rising state from the time when the confirmation flag F becomes “1”. Detect in sequence order t.

In step S19, the peak detector 36, time as the detection start time point change time Tc detected in step S18, smallest voltage moving average AV _t time to voltage moving average AV _t calculated in step S13 Detection starts in sequence order t.

Then, in step S20, the peak detector 36 sequentially determines whether the current measurement value PI _t is less than the current threshold value TH in parallel with the detection in step S19. As a result of this determination, if the current measurement value PI _t is still larger than the current threshold value TH, the process returns to step S19 with NO in step S20, and the peak detector 36 obtains the voltage moving average value AV _t at the time point at which the current measurement value PI _t is minimum. Continue to detect.

On the other hand, if the current measurement value PI _t is equal to or less than the current threshold value TH, the process proceeds to step S21. In step S21, the peak detection unit 36 detects a time point when the current measurement value PI _t is equal to or less than the current threshold value TH as the cranking end time Te (see FIG. 6), and the voltage moving average value AV at the time point when the peak value is minimized. The detection of _t ends. Then, the peak detector 36, peak detector 36 sets the thus detected voltage moving average value AV _t the second peak P _2.

That is, in a series of steps from Step S19 to Step S21, the peak detection unit 36 becomes the smallest in the voltage moving average values AV _Tc ,..., AV _Te from the change time Tc to the cranking end time Te. It will detect a voltage moving average AV _t time.

Further, the values of N and M are set based on the fluctuation cycle of the waveform of the voltage moving average values AV _Tc ,..., AV _Te from the change time Tc to the cranking end time Te. The value of N is also a result of removing up to a low-frequency component of the set beyond the range of the fluctuation period voltage measurement value PV _t. For this reason, in this embodiment, as described above, N is a value of “16” and M is “10” so that the value of M is also within the fluctuation period of the waveform. The value is set (see FIG. 6). Further, since the voltage value V or current value I at the time of cranking varies depending on the vehicle, the values of N and M are provided so as to be appropriately variable as parameters set in advance, and are set to optimum values for each vehicle.

In step S22, the state diagnosis unit 37 diagnoses the state of the battery B based on voltage measurement value PV _t at the second peak _{P 2} detected in step S21. As a result of this diagnosis, when the voltage measurement value PV _{t at} the second peak P ₂ is equal to or less than a predetermined threshold, the state diagnosis unit 37 diagnoses that the battery B is deteriorated and turns on the alarm 13. Warning.

By thus performing a series of steps from step S11 to step S22, and reliably detect the second peak P _2, the state of the battery B is accurately be diagnosed.

<Advantages of battery state diagnosis apparatus and battery state diagnosis method>
As described above, according to the present embodiment, the latest 16 (N, natural number) voltage moving average value AV _t (moving average value, voltage value V _t (measured value, P _t ) of the voltage value V is measured. Since A _t ) is calculated and the second peak P ₂ is detected, it is possible to remove the high-frequency component caused by the environmental noise and suppress the erroneous detection of the second peak P ₂ due to the influence of the environmental noise. Further, with the high-frequency component removed in this manner, ascending “1” or descending “0” is sequentially determined as compared with the immediately preceding voltage moving average value AV _t-1 (moving average value, A _t-1 ). Then, a change time Tc at which the determination result turns from rising “1” to falling “0” is detected, and the second peak P ₂ is detected from this changing time Tc. Thus, the second peak P ₂ reliably detected, it is possible to improve the accuracy of state diagnosis of the battery B.

Further, according to the present embodiment, as a result of the upper and lower determinations with respect to each of the voltage moving average value AV _t (moving average value, A _t ), the number of times that the increase “1” continues is 10 (M, natural number) or more. When the number of consecutive times is determined to be 10 times or more, the time point when the upper and lower determination results turn down to “0” is detected as the change time point Tc. since the start to detect the second peak P _2, and prevented from being erroneously detected steep variation from inrush current immediately after cranking the second peak P _2, and more precisely detect a second peak P ₂ can do.

(Second Embodiment)
Next, with reference to FIG.7 and FIG.8, 2nd Embodiment of the battery condition diagnostic apparatus and battery condition diagnostic method which concern on this invention is described.
Note that the same or equivalent parts as those in the first embodiment are given the same or equivalent reference numerals in the drawings, and the description thereof is omitted or simplified.

<Microcomputer configuration>
First, the configuration of the microcomputer (control unit) 40 of the present embodiment will be described with reference to FIG. FIG. 7 is a functional block diagram functionally illustrating the software configuration of the microcomputer 40 according to the embodiment.

As shown in FIG. 7, in this embodiment, the second peak P ₂ is used by using only the current value I and the current measurement value PI _{t of} the current sensor 12 without using the voltage value V and the voltage measurement value PV _t of the voltage sensor 11. Is detected. For this reason, the sample acquisition unit 41 of the microcomputer 40 according to the present embodiment acquires only the current value I of the current sensor 12 in a predetermined sampling cycle as the current measurement value PI _t in time series order t. Further, the sample taking unit 41 outputs the fetched current measured value PI _t in the memory 20 then stores the measurement data storage area 21 of the memory 20.

Moving average calculation section 42 reads the current measured value PI _t stored in the memory 20, to each the current measurement value PI _t, (the value of Similarly, "16" in this embodiment) last N current The current moving average values of the measured values PI _t , PI _t−1 , PI _t−2 ,..., PI _t−15 are calculated in time series order t.

The up / down determination unit 43 reads the current moving average value AI _t of the moving average calculation unit 42, and selectively selects whether the current moving average value AI _t-1 is higher or lower than the previous current moving average value AI _{t-1 in} chronological order t. Determination is made as a numerical value as the change direction CD _t .

The continuity determination unit 44 reads the change direction CD _t of the up / down determination unit 43 and sequentially counts the number of consecutive “0” drops in the change direction CD _t in time series order t. The continuity determination unit 34 determines whether or not the counted number of consecutive “0” drops is equal to or greater than M (also in this embodiment, the value “10”). When it is determined that the number of consecutive “0” drops is 10 or more, the continuity determination unit determines that the current moving average value AI _t is in a continuously decreasing state (downward state). Then, the value “1” is substituted into the confirmation flag F.

Change detecting unit 45 detects a is a moment when the change direction CD _t from the time when the confirmation flag F becomes "1" starts to rise "1" from the lowered "0" change time Tc in chronological order t.

The peak detection unit 46 detects the current moving average value AI _t at the maximum time in the current moving average values AI _Tc ,..., AI _Te from the change time Tc to the cranking end time Te. setting the current moving average value AI _t as the second peak _{P 2.}
Other configurations are the same as those in the first embodiment.

<Microcomputer processing procedure, battery status diagnosis method>
Next, a processing procedure of the microcomputer 40 configured as described above will be described. FIG. 8 is a flowchart for explaining processing performed by the microcomputer 40 of the present embodiment.
Note that the description will mainly focus on differences from the flowchart of the first embodiment (see FIG. 3).

As shown in FIG. 8, in step S31, the current value I is input to the sample acquisition unit 41 of the microcomputer 40 and is acquired as the current measurement value PI _t at a predetermined sampling period. In step S32, the current measurement value PI _t periodically taken by the sample taking unit 41 is stored and held in the measurement data storage area 21 of the memory 20 in time series order t.

In step S33, the moving average calculation section 42 reads the current measured value PI _t from the memory 20, this current measured value PI _t last 16 current measured values _PI t for each, PI _t-1, PI _{t- 2} ,..., PI _t-15 current moving average values AI _t are calculated in time series order t.

In step S34, the up / down determination unit 43 determines whether the current moving average value AI _t calculated in step S33 is an increase “1” or a decrease “0” compared to the previous current moving average value AI _t−1. Each determination is made selectively in time series order t, and this determination result is digitized as the change direction CD _t .

In step S <b> 35, the continuation determination unit 44 sequentially counts the number of consecutive “0” drops in the change direction CD _t in step S <b> 34 in time series order t. In step S <b> 36, the continuation determination unit 44 determines whether or not the counted number of consecutive “0” decreases is 10 or more.

When the count of the continuous number of descending “0” is 10 times or more, the process proceeds to step S37 with YES in step S36. In step S <b> 37, the continuity determination unit 44 determines the current state of the current moving average value AI _t as it continues to decrease, and assigns “1” to the determination flag F.

At step S38, the change detection unit 45, the confirmation flag F is after the timing when the "1", change the time Tc that changing direction CD _t at step S34 turns to rise "1" from the lowered "0" in its lowered situation Are detected in chronological order t.

In a series of steps from Step S39 to Step S41, the peak detection unit 46 determines the current at the time when the current moving average values AI _Tc ,..., AI _Te from the change time Tc to the cranking end time _Te are maximum. The moving average value AI _t is detected. Peak detector 36 sets the thus detected current moving average AI _t the second peak P _2.
Other steps are the same as those in the first embodiment.

<Advantages of battery state diagnosis apparatus and battery state diagnosis method>
As described above, according to the present embodiment, as in the first embodiment, occurrence of erroneous detection of the second peak P ₂ due to the influence of environmental noise is suppressed, and the second peak P ₂ is accurately detected. be able to.

This is the end of the description of specific embodiments. However, aspects of the present invention are not limited to these embodiments, and modifications, improvements, and the like can be made as appropriate.
For example, in the first and second embodiments, the peak detector 36 and 46 is sequentially determined whether the current measurement value PI _t is equal to or less than the current threshold value TH, the current measured value PI _t is the current threshold TH Although it has been configured to detect the moment when the cranking is finished as Te, the present invention is not limited to this. For example, the cranking end time Te may be set in advance in the parameter storage area 22 of the memory 20, and the peak detectors 36 and 46 may read this value as appropriate.

Here, the features of the embodiment of the battery state diagnosis device and the battery state diagnosis method according to the present invention described above are briefly summarized and listed in the following [1] to [6], respectively.
[1]
A battery state diagnosis device (10) for diagnosing the state of a battery (B) when an engine (E) mounted on a vehicle is cranked,
In a predetermined sampling cycle, the voltage value (V) or current value (I) of the battery (B) is taken as a measurement value P (voltage measurement value: PV, current measurement value: PI) in chronological order t (t = 1, 2). ,..., T) and a storage unit (memory, 20)
For each of the measurement values P _t (voltage measurement value: PV _t , current measurement value: PI _t ) stored and held in the storage unit (20), the latest N (N is a natural number of 2 or more) pieces of the measurement. value _{(P t, P t-1} , P t-2, ..., P t-N + 1) { voltage _{measurement: (PV t, PV t-} 1, PV t-2, ..., PV t-N + 1), the current Measurement value: (PI _t , PI _t−1 , PI _t−2 ,..., PI _{t−N + 1} )} moving average value A _t (voltage moving average value: AV _t , current moving average value: AI _t ) is calculated. For each moving average value A _t (voltage moving average value: AV _t , current moving average value: AI _t ), the immediately preceding moving average value A _t-1 (voltage moving average value: AV _t-1). , the current moving average value: AI _t-1) sequentially determine rising or falling of the as compared to then, the determination result, the measured value _t (voltage measurement value: PV _t, current measurements: PI _t) is lowered from a raised when the voltage value of (V), the measurement value _{P t} (voltage measurement value: PV _t, current measurements: _PI t) Is a current value (I), a change time Tc from falling to rising is detected, and the moving average value (A _Tc ,..., A _Te ) between the change time Tc and the cranking end time Te is detected. {Voltage moving average value: (AV _Tc ,..., AV _Te ), current moving average value: (AI _Tc ,..., AI _Te )}, the measured value P _t (voltage measured value: PV _t , current measured value) : PI _t ) is the minimum when the voltage value (V), and the maximum when the measurement value P _t (voltage measurement value: PV _t , current measurement value: PI _t ) is the current value (I). the moving average value _{a t} (voltage moving average of: AV _t, current moving average The AI _t) as the second peak _{(P 2),} the measured value _{P t} (voltage measurement value at the second peak _{(P 2):} PV _t, current measurements: PI _t) or the moving average value _A t ( A control unit (microcomputer, 30) for diagnosing the state of the battery (B) based on the voltage moving average value: AV _t and the current moving average value: AI _t ;
A battery state diagnosis apparatus (10) comprising:
[2]
The control unit (microcomputer, 30) uses the measurement value P _t (voltage measurement value: voltage measurement value) as the determination result for each of the moving average value A _t (voltage movement average value: AV _t , current movement average value: AI _t ). When PV _t , current measurement value: PI _t ) is a voltage value (V), an increase occurs, and the measurement value P _t (voltage measurement value: PV _t , current measurement value: PI _t ) is equal to the current value (I). In this case, it is sequentially determined whether or not the number of consecutive descents is equal to or greater than M (M is a natural number equal to or greater than 2), and the determination is performed when it is determined that the number of consecutive decreases is equal to or greater than M. When the measurement value P _t (voltage measurement value: PV _t , current measurement value: PI _t ) is a voltage value (V), the result falls, and the measurement value P _t (voltage measurement value: PV _t , current measurement). value: PI _t) is the current value of the time to turn on the rise in the case of (I), wherein Battery condition diagnosis apparatus according to [1], wherein the detecting as of the time Tc (10).
[3]
The values of N and M are the moving average value (A _Tc ,..., A _Te ) {voltage moving average value: (AV _Tc ,..., AV _Te ) from the change time Tc to the cranking end time _Te. ,), Current moving average value: (AI _Tc ,..., AI _Te )} are set based on the fluctuation cycle of the waveform, respectively, and the battery state diagnosis device according to the above [1] or [2] (10).
[4]
A battery state diagnosis method for diagnosing the state of a battery (B) when an engine (E) mounted on a vehicle is cranked,
In a predetermined sampling cycle, the voltage value (V) or current value (I) of the battery (B) is taken as a measurement value P (voltage measurement value: PV, current measurement value: PI) in chronological order t (t = 1, 2). , ..., T)
For each of the stored measurement values P _t (voltage measurement value: PV _t , current measurement value: PI _t ), the latest N (N is a natural number of 2 or more) measurement values (P _t , P _{t). −1} , P _t−2 ,..., P _{t−N + 1} ) {Voltage measurement values: (PV _t , PV _t−1 , PV _t−2 ,..., PV _{t−N + 1} ), current measurement values: (PI _t , PI _t−1 , PI _t−2 ,..., PI _{t−N + 1} )} are calculated, and a moving average value A _t (voltage moving average value: AV _t , current moving average value: AI _t ) is calculated,
For each of the moving average value A _t (voltage moving average value: AV _t , current moving average value: AI _t ), the immediately preceding moving average value A _t-1 (voltage moving average value: AV _t-1 , current Moving average value: AI _t-1 ) and sequentially judging whether it is rising or falling,
When the measurement value P _t (voltage measurement value: PV _t , current measurement value: PI _t ) is a voltage value (V), the determination result is a decrease from an increase, and the measurement value P _t (voltage measurement value: PV _t , when the current measurement value PI _t ) is the current value (I), a change time Tc when the current value changes from falling to rising is detected.
The moving average value (A _Tc ,..., A _Te ) {Voltage moving average value: (AV _Tc ,..., AV _Te ) from the change time Tc to the cranking end time Te: Current moving average value: (AI _Tc ,..., AI _Te )}, when the measured value P _t (voltage measured value: PV _t , current measured value: PI _t ) is a voltage value (V), the measured value P _t ( When the voltage measurement value: PV _t , the current measurement value: PI _t ) is the current value (I), the moving average value A _t (voltage moving average value: AV _t , current moving average value: AI) at the time when the voltage reaches the maximum value. _t ) as the second peak (P ₂ ),
The measurement value P _t (voltage measurement value: PV _t , current measurement value: PI _t ) or the moving average value A _t (voltage moving average value: AV _t , current moving average value) at the second peak (P ₂ ): A battery state diagnosis method characterized by diagnosing the state of the battery (B) based on AI _t ).
[5]
As the determination result for each of the moving average value A _t (voltage moving average value: AV _t , current moving average value: AI _t ), the measured value P _t (voltage measured value: PV _t , current measured value: PI _t ) If the measured value P _t (voltage measured value: PV _t , current measured value: PI _t ) is the current value (I), the number of consecutive decreases Sequentially determine whether or not M (M is a natural number greater than or equal to 2) times,
When it is determined that the number of consecutive times is equal to or greater than the M times, the determination result indicates that the measurement value P _t (voltage measurement value: PV _t , current measurement value: PI _t ) is a voltage value (V). If the measured value P _t (voltage measured value: PV _t , current measured value: PI _t ) is the current value (I), the time point when the measured value P _t starts to rise is detected as the change time point Tc. The battery state diagnosis method according to [4] above, characterized by:
[6]
The values of N and M are the moving average value (A _Tc ,..., A _Te ) {voltage moving average value: (AV _Tc ,..., AV _Te ) from the change time Tc to the cranking end time _Te. ,), Current moving average value: (AI _Tc ,..., AI _Te )} are set based on the fluctuation cycle of the waveform, respectively, and the battery state diagnosis method according to the above [4] or [5] .

DESCRIPTION OF SYMBOLS 10 Battery condition diagnostic apparatus 11 Voltage sensor 12 Current sensor 13 Alarm 20 Memory (memory | storage part)
21 Measurement data storage area 22 Parameter storage area 30, 40 Microcomputer (control unit)
31, 41 Sample acquisition unit 32, 42 Moving average calculation unit 33, 43 Up / down determination unit 34, 44 Continuous determination unit 35, 45 Change detection unit 36, 46 Peak detection unit 37, 47 State diagnosis unit B Battery S Starter motor E Engine V Voltage value I Current value P Measured value PV Voltage measured value (Measured value)
PI Current measurement value (measurement value)
A Moving average value AV Voltage moving average value (moving average value)
AI Current moving average value (moving average value)
CD change direction F confirmation flag Tc change time Te cranking end time TH current threshold

Claims (4)

A battery state diagnosis device for diagnosing a battery state when an engine mounted on a vehicle is cranked,
A storage unit that stores and holds the voltage value or current value of the battery in a time-series order t (t = 1, 2,..., T) as a measurement value P at a predetermined sampling period;
For each of the measured values P _t stored and held in the storage unit, the latest N (N is a natural number of 2 or more) measured values (P _t , P _t−1 , P _t−2 ,..., P calculating a _{t-N + 1)} moving average value a _t of said moving relative to each average value a _t, sequentially determines whether raising or lowering of the as compared to the moving average value a _t-1 immediately preceding, the When the measurement value _Pt is a voltage value, the determination result detects a change time Tc that changes from rising to falling, and when the measurement value _Pt is a current value, the change time Tc changes from falling to rising. In the moving average value (A _Tc ,..., A _Te ) until the ranking end time Te, the minimum is obtained when the measured value P _t is a voltage value, and the measured value P _t is a current value. the moving average value a _t at which the maximum and the second peak, put the second peak A control unit for diagnosing the condition of the battery based on the measured value P _t or the moving average value A _t that,
A battery state diagnosis apparatus comprising: Wherein the control unit, as the determination result of the moving average value A _t respectively, increases when the measured value P _t is the voltage value, the measured value P _t is lowered in the case of current value, continuous In the case where it is sequentially determined whether or not the number of times is M (M is a natural number greater than or equal to 2) times, and the number of consecutive times is determined to be M or more, the determination result is the measured value P _t The battery state diagnosis apparatus according to claim 1, wherein a time point when the voltage value is decreasing and a time point when the measured value Pt is increased when the measured value _Pt is a current value is detected as the change time point Tc. The values of N and M are set based on the fluctuation period of the waveform of the moving average value (A _Tc ,..., A _Te ) from the change time Tc to the cranking end time Te. The battery state diagnosis apparatus according to claim 1 or 2, characterized in that A battery state diagnosis method for diagnosing a battery state when cranking an engine mounted on a vehicle,
The voltage value or current value of the battery is stored and held in time series order t (t = 1, 2,..., T) as a measured value P at a predetermined sampling period,
For each of the stored measurement values P _t , the latest N (N is a natural number of 2 or more) measurement values (P _t , P _t−1 , P _t−2 ,..., P _{t−N + 1} ). moving an average value a _t of,
The moving for each average value A _t, sequentially determines whether to raise or lower a of in comparison with the moving average value A _t-1 immediately preceding,
When the measurement value _Pt is a voltage value, the determination result detects a change time Tc when the measurement value Pt changes from an increase to a decrease, and when the measurement value _Pt is a current value, the change time Tc changes.
In the moving average value (A _Tc ,..., A _Te ) from the change time Tc to the cranking end time Te, when the measured value P _t is a voltage value, the minimum is the measured value P _t. the moving average value a _t at which the maximum and the second peak when the current value,
Battery condition diagnosis method characterized by diagnosing the status of the battery based on the measured value P _t or the moving average value A _t in the second peak.

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