JP2012070568A - Vehicle system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle system which prevents deterioration (high rate deterioration) of a battery by high rate discharge by restricting acceleration of a vehicle.SOLUTION: The vehicle system controls a vehicle 1 equipped with a power source including a secondary battery 11 and a motor which performs power running by electric energy from the secondary battery, and has an acceleration limiting means which limits magnitude of acceleration in a speed increasing direction so that a control value C, obtained by using acceleration B in a direction of acceleration detected by an acceleration detecting means and battery temperature T (S2) detected by a battery temperature detecting means and by setting the influence of increase of acceleration B and the influence of the increase of the battery temperature T to a conflicting relation, may satisfy a predefined range (below A)(S3).

Description

  The present invention relates to a vehicle system that controls a vehicle including a secondary battery and a power source.

In recent years, vehicles such as hybrid vehicles, plug-in hybrid vehicles, and electric vehicles using a chargeable / dischargeable secondary battery (hereinafter also simply referred to as a battery) as a driving power source are known.
For such a vehicle, for example, Patent Document 1 discloses that the deterioration of the secondary battery due to the discharge performed at a relatively large current with respect to the battery capacity, which is referred to as high-rate discharge, is suppressed in the power performance of the vehicle. A control device for a secondary battery is disclosed. The control device detects a discharge current value from the secondary battery, and calculates an evaluation value related to deterioration of the secondary battery due to high-rate discharge based on the history of the discharge current value. And based on this evaluation value, the value of discharge electric power is controlled.

JP 2009-123435 A

By the way, as will be described in detail later, according to the study by the present inventors, the deterioration of the battery due to a large current discharge (hereinafter also referred to as a high rate discharge) that causes a relatively large discharge current (for example, 10 C or more) than usual (hereinafter also referred to as high rate discharge). It has been found that there is a correlation between the relationship between the acceleration of the vehicle and the battery temperature.
However, the secondary battery control device disclosed in Patent Document 1 does not describe the detection of the acceleration of the vehicle or the battery temperature of the battery, or the use thereof.

  This invention is made | formed in view of this knowledge, Comprising: The vehicle system which restrict | limits the acceleration of a vehicle and prevents the deterioration (high-rate deterioration) of the battery by high-rate discharge is provided.

  One aspect of the present invention is a vehicle comprising: a secondary battery mounted on a vehicle; and a power source that drives the vehicle and includes a motor that performs powering by electric energy from the secondary battery. Is a vehicle system for controlling the acceleration of the vehicle, the acceleration detecting means for detecting the acceleration in the acceleration direction of the vehicle, the battery temperature detecting means for detecting the battery temperature of the secondary battery, and the acceleration detecting means A control value obtained by using the acceleration in the acceleration direction and the battery temperature detected by the battery temperature detecting means, and determining a relationship in which the influence of the increase in acceleration and the influence of the increase in battery temperature are in conflict Is a vehicle system having acceleration limiting means for limiting the magnitude of acceleration in the speed increasing direction so as to satisfy a predetermined range.

By the way, when the battery is discharged to obtain acceleration in the acceleration direction of the vehicle, the higher the acceleration, the larger the required discharge power from the battery, and the higher the rate of discharge, the higher the battery's high rate deterioration. Easy to progress.
In addition, since the discharge power that can be taken out from the battery is smaller as the battery temperature is lower, when considering the battery temperature with the same discharge power, the lower the battery temperature, the greater the burden on the battery 11 during high-rate discharge. Deterioration is easy to progress. That is, the acceleration of the vehicle and the battery temperature have characteristics opposite to the deterioration of the battery (the battery is more likely to deteriorate as the acceleration increases and the battery temperature decreases).

  On the other hand, in the above-described vehicle system, using a control value determined in a relationship in which the influence of the increase in acceleration and the influence of the increase in battery temperature are contradictory, so that the control value satisfies a predetermined range, Acceleration limiting means for limiting the magnitude of acceleration of the vehicle is provided. For example, the control value changes in the same direction depending on whether the acceleration in the acceleration direction, which is the direction in which the high rate deterioration of the battery proceeds, is large or the battery temperature is low. Two parameters (acceleration and battery temperature) are integrated and control is possible using one control value. Therefore, control is easy. In addition, according to the vehicle system described above, the discharge of large discharge power from the battery (occurrence of high-rate discharge) accompanying the rapid acceleration of the vehicle is limited according to the battery temperature, and high-rate deterioration of the battery is prevented. In particular, when the battery temperature at which deterioration is likely to occur is low, the magnitude of acceleration is likely to be limited, so that high-rate deterioration of the battery can be prevented appropriately.

In addition, as a control value determined in a relationship in which the influence of the increase in acceleration and the influence of the increase in battery temperature are contradictory, when acceleration is B and the battery temperature is T, for example, C = B / T is given. A control value C is mentioned. In addition, the control value C can be set to C = mB−nT (m and n are positive constants), C = B / T ^2, and the like according to the battery characteristics.

In addition to a motor driven by a battery, the power source for driving the vehicle may include an engine (an internal combustion engine). Further, the motor may be a motor that performs power running with electric energy from the battery, but may be a motor that can perform power regeneration in addition to power running.
Further, driving control by a known inverter or power running / regenerative control can be used for driving the motor.

The acceleration detection means may be any acceleration detection means that can detect acceleration in the acceleration direction of the vehicle, but can also detect acceleration in the deceleration direction. Moreover, as an acceleration detection means, the detection means using the acceleration sensor which detects the acceleration of a vehicle is mentioned. In addition, there is a means for calculating the acceleration by calculation from the rotation (rotation speed) of the wheel or the output of the vehicle speed sensor.
Examples of the battery temperature detection means include detection means using a temperature sensor such as a thermistor or an infrared radiation temperature sensor for measuring the battery temperature of a battery mounted on the vehicle.

  Further, the acceleration limiting means acts on the driving condition of the vehicle driving source when the control value exceeds a predetermined range, and reduces the acceleration in the acceleration direction, that is, the driving force by the driving source. It is means for changing the driving condition in the direction of decreasing. For example, when the drive source is a motor (in the case of HV, PHV, EV), control of the inverter that instructs the inverter that controls the power supplied from the battery to the motor to reduce the supplied power Means are mentioned. In addition, when an engine is also provided as a driving source (in the case of HV and PHV), an injector for injecting fuel into the combustion chamber is instructed to limit the amount of fuel to be injected or to perform fuel cut. A control means is mentioned.

  Further, in the above vehicle system, when the acceleration is B and the battery temperature is T, the acceleration limiting means gives the control value C by C = B / T, and the control value C is It is preferable that the vehicle system limit the magnitude of the acceleration so that C <A with respect to a predetermined threshold A.

According to the study by the present inventors, the rate of increase in internal resistance per unit distance in an in-vehicle secondary battery, which is an index of the deterioration rate of the battery, and the value obtained by dividing the vehicle acceleration B by the battery temperature T It has been found that there is a correlation with (= B / T). This is because, as described above, the vehicle acceleration B and the battery temperature T have characteristics that conflict with the deterioration of the battery. Therefore, by setting B / T to be the control value C, the control value C does not exceed the threshold value A (C <A), so that the deterioration of the battery progresses, for example, the internal resistance per unit distance in the battery increases. It is thought that the rate can be reduced.
Based on this, in the vehicle system described above, the acceleration limiting means gives the control value C by C = B / T, and the acceleration value is such that C <A with respect to the predetermined threshold A. Limit the size. Thus, high rate deterioration of the battery can be reliably prevented.

  Furthermore, the vehicle system described above includes threshold setting means for setting the threshold A, and the threshold setting means for setting the threshold A to a smaller value as the deterioration of the secondary battery progresses. Good.

  The vehicle system described above includes threshold setting means for setting the threshold A to a smaller value as the battery progresses. For this reason, since the control value C is controlled to be smaller as the deterioration of the battery progresses, the progress speed of the battery deterioration can be further reduced as the deterioration of the battery progresses.

  Furthermore, in the above-described vehicle system, the vehicle system further includes a deterioration detection unit that detects a degree of deterioration of the secondary battery, and the threshold setting unit increases the degree of deterioration detected by the deterioration detection unit. A vehicle system in which the threshold A is set to a small value is preferable.

  The vehicle system described above includes a deterioration detection unit that detects the degree of battery deterioration, and the threshold A is set to a smaller value as the degree of battery deterioration detected by the threshold setting unit increases. For this reason, the vehicle system itself can appropriately suppress the progress rate of the battery deterioration according to the degree of battery deterioration, and can sufficiently draw out the battery characteristics.

  As the deterioration detection means, for example, a battery measured by a direct current resistance (DC-IR) measurement method (or a method according to the DC-IR measurement method) using current values and voltage values in a battery in use. And calculating the numerical value obtained by dividing the internal resistance value by the initial value of the internal resistance of the battery to detect the degree of deterioration of the battery.

  Furthermore, in any one of the vehicle systems described above, the secondary battery may be a vehicle system that is a non-aqueous electrolyte type secondary battery.

By the way, a non-aqueous electrolyte type secondary battery such as a lithium ion secondary battery is more likely to be diffusion-controlled than an aqueous electrolyte type secondary battery such as a Ni-MH battery, and thus the above-mentioned problem of high rate deterioration occurs. It's easy to do.
Based on this, in the above-described vehicle system, the secondary battery is a non-aqueous electrolyte type secondary battery in which diffusion rate control is likely to occur. Therefore, it is possible to reliably prevent high-rate deterioration occurring in the non-aqueous electrolyte type secondary battery. it can.

It is explanatory drawing which shows the vehicle provided with the vehicle system concerning Embodiment 1 and modification 1. FIG. It is a graph which shows the relationship between the control value C and the internal resistance increase rate per unit distance of a battery. 3 is a flowchart showing control contents of the vehicle system according to the first embodiment. 7 is a flowchart showing control contents of a vehicle system according to a first modification. 7 is a flowchart showing control contents of a vehicle system according to a first modification.

(Embodiment 1)
Next, the vehicle system according to the first embodiment of the present invention will be described with reference to FIGS.
First, a vehicle 1 to which a vehicle system VS1 according to the first embodiment is applied will be described with reference to FIG.
The vehicle 1 includes a battery pack 10, a motor 20, an engine 30, an acceleration sensor 40, and a plurality of lithium ion secondary batteries (hereinafter simply referred to as batteries) 11, 11. The hybrid vehicle includes a temperature sensor 50 and an ECU (Electronic Control Unit) 60. The vehicle 1 includes a power generator 70, a PCU (Power Control Unit) 80, a power distribution mechanism 90 that distributes power generated by the engine 30, a speed reducer 100 that reduces and outputs the rotational speed of the power, and the speed reducer. A wheel 110 is rotated by power output through 100.
The vehicle system VS1 is realized by a program executed by the ECU 60.

Of the vehicle 1, the PCU 80 includes an inverter 81 that converts AC power generated by the generator 70 into DC power, and a converter 82 that adjusts voltage.
The engine 30 is an internal combustion engine that includes a plurality of fuel chambers and injectors that inject fuel into the fuel chambers, all not shown. Note that the amount of fuel injected by the injector is controlled by the ECU 60 described above. Also, the power generated by the engine 30 is distributed by the power distribution mechanism 90 into a path for driving the wheels 110 via the speed reducer 100 and a path for generating power by driving the generator 70.
Among these, the electric energy generated by the generator 70 is used by the motor 20 or stored in the battery 11 (the assembled battery 10) according to the driving state of the vehicle 1 and the charged state of the battery 11 (the assembled battery 10). It is done.

  The motor 20 is a three-phase AC motor, and is driven by electric energy generated by the generator 70 in addition to electric energy stored in the battery 11 (the assembled battery 10). Specifically, the driving force generated by the motor 20 is transmitted to the wheel 110 via the speed reducer 100. Accordingly, the motor 20 assists the engine 30 to travel (power running) the vehicle 1 or causes the vehicle 1 to travel (power running) only by the driving force from the motor 20.

  The acceleration sensor 40 is a known semiconductor type acceleration sensor, and is disposed in the passenger compartment (near the driver's seat) of the vehicle 1 and measures a change in vehicle speed (acceleration B). Further, the temperature sensor 50 is arranged such that the temperature measuring unit is in contact with the outside of the battery case of one battery 11 in the assembled battery 10, and measures the battery temperature T of the battery 11.

  The ECU 60 includes a microcomputer (hereinafter also referred to as a microcomputer) 61 that includes a CPU, a ROM, and a RAM (not shown) and operates according to a predetermined program. The ECU 60 is connected to the assembled battery 10, the motor 20, the engine 30, the acceleration sensor 40, the temperature sensor 50, the generator 70 and the PCU 80, and the driving state of the vehicle 1, the acceleration B measured by the acceleration sensor 40, The devices mounted on the vehicle 1 are controlled based on the battery temperature T of the battery 11 measured by the temperature sensor 50.

  By the way, the present inventors examined the relationship between the acceleration B in the speed increasing direction of the vehicle and the battery temperature T against the deterioration of the battery mounted on the vehicle. Specifically, a running experiment was performed using a vehicle VH1 equipped with the same battery 11 as the battery 11 (the assembled battery 10) described above, and the progress of deterioration of the battery 11 before and after the running experiment was confirmed. In addition, this vehicle VH1 is a vehicle which does not have the acceleration limiting means (steps S3-S6) mentioned later among the vehicles 1 mentioned above.

First, the internal resistance of the battery 11 (the assembled battery 10) was measured before the running test with the vehicle VH1. Specifically, before the vehicle is mounted, the internal resistance Rx of the battery 11 is measured in a temperature environment of 25 ° C. by a known DC resistance (DC-IR) measurement method using a DC power supply device, a voltmeter and an ammeter (not shown). taking measurement.
After the measurement, a plurality of batteries 11, 11 were assembled in the assembled battery 10 and mounted on the vehicle VH1, and a running test was performed. Specifically, on a flat road, the vehicle is stopped once by sudden acceleration (to the extent that the vehicle speed increases from 0 km / h to 100 km / h in 10 seconds) and sudden deceleration once each. This was repeated as a run. At the time of sudden acceleration in each run, the discharge current of the battery 11 reaches a maximum of 30 C, which is a high rate discharge. In addition, the maximum acceleration in one driving | running | working (rapid acceleration) is made into acceleration BP1 of the time, and let the average of acceleration BP1 of each time be average acceleration AB1. Further, an average value of the battery temperature T during the running test is defined as an average battery temperature AT1. Then, for the vehicle VH1, a value AC1 (= AB1 / AT1) obtained by dividing the average acceleration AB1 by the average battery temperature AT1 was calculated.
Furthermore, after carrying out the running test, the internal resistance of the battery 11 was measured again. Specifically, the internal resistance of the battery 11 dropped from the vehicle VH1 was measured in the same manner as before the running test.

Further, vehicles VH2 and VH3 similar to the vehicle VH1 were prepared. Like the vehicle VH1, these vehicles VH2 and VH3 are vehicles that do not have the acceleration limiting means (steps S3 to S6) described later, among the vehicles 1 described above.
A running test was also conducted on these vehicles VH2 and VH3. However, for the vehicle VH2, sudden acceleration (specifically, the vehicle speed is 0 km / h during 30 seconds under the condition that the maximum acceleration BP2 of the vehicle VH2 is smaller than the maximum acceleration BP1 of the vehicle VH1 described above. The vehicle VH1 is different from the vehicle VH1 in that the vehicle travels at a speed of about 80 km / h. In each running of the vehicle VH2, even during rapid acceleration, the battery 11 is subjected to a high rate discharge in which a maximum discharge current of 20 C flows.
The vehicle VH3 repeated the same traveling as the vehicle VH2, but differs from the vehicle VH2 in that a traveling test was performed when the battery temperature T was relatively high as compared to the vehicle VH2. For example, the running test of the vehicle VH3 was performed in a region where the outside air temperature was generally higher than the region where the running test of the vehicles VH1 and VH2 was performed. In each run of the vehicle VH3, the battery 11 is subjected to high-rate discharge in which a maximum discharge current of 20 C flows through the battery 11 during rapid acceleration.

For the vehicles VH2 and VH3, the internal resistance was measured before and after the running test in the same manner as the vehicle VH1. And the change of the internal resistance of the battery 11 in each vehicle VH1, VH2, VH3 before and after a running test was investigated. Specifically, the difference obtained by subtracting the internal resistance Rx before the running test from the value of the internal resistance Ry after the running test of each battery 11 of each vehicle VH1, VH2, VH3 is divided by the internal resistance Rx before the running test. The internal resistance increase rate Rm (= (Ry−) per unit distance is calculated by calculating the internal resistance increase rate ((Ry−Rx) / Rx) and dividing the internal resistance increase rate by the total travel distance M of the travel test. Rx) / Rx / M) was calculated. The internal resistance increase rates Rm per unit distance of the vehicles VH1, VH2, and VH3 are Rm1, Rm2, and Rm3, respectively.
Further, for each battery 11 of each vehicle VH2, VH3, values AC2 (= AB2 / AT2), AC3 (= AB3 / AT3) obtained by dividing average accelerations AB2, AB3 by average battery temperatures AT2, AT3 in the same manner as vehicle VH1. ) Respectively.

  FIG. 2 is a graph showing the relationship between the value AC (= AB / AT) obtained by dividing the average acceleration AB by the average battery temperature AT and the internal resistance increase rate Rm per unit distance of the battery 11. On this graph, plot points corresponding to the vehicles VH1, VH2, and VH3 are shown. And the approximated curve was created on the graph from these plot points. From this result, it can be seen that as the value AC increases, the internal resistance increase rate Rm per unit distance increases.

By the way, in the vehicle 1 in which the battery 11 which is a lithium ion secondary battery is mounted on the vehicle, when the acceleration B in the acceleration direction of the vehicle 1 is obtained, the required discharge power from the battery 11 increases as the acceleration B is increased. Is likely to be high, and a high rate discharge is likely to occur. For this reason, the high-rate deterioration of the battery 11 of the vehicle 1 is likely to proceed. In FIG. 2, in the vehicle VH1 in which the average acceleration AB1 is relatively larger than that of the vehicle VH2, the internal resistance increase rate Rm1 is larger than the internal resistance increase rate Rm2 per unit distance in the vehicle VH2, that is, the deterioration. Is supported by the large
Further, since the discharge power that can be taken out from the battery 11 is smaller as the battery temperature T is lower, when considering the battery temperature with the same discharge power, the lower the battery temperature T, the greater the burden on the battery 11 during high-rate discharge. High-rate deterioration of the battery 11 is likely to proceed. This is because in the vehicle VH1 whose average battery temperature AT1 is relatively lower than that of the vehicle VH3, the internal resistance increase rate Rm1 is larger than the internal resistance increase rate Rm3 per unit distance in the vehicle VH3, that is, the deterioration is large. It is supported from.
Therefore, the larger the value AC, that is, the greater the average acceleration AB, or the lower the average battery temperature AT, the greater the internal resistance increase rate Rm per unit distance that indicates the deterioration of the battery 11. I understand that.

Based on the above knowledge, in the first embodiment, a control value obtained by integrating two contradictory parameters (acceleration B and battery temperature T) with a value obtained by dividing the acceleration B at each time point during traveling of the vehicle 1 by the battery temperature T. Used as C, control is performed so that the control value C satisfies a predetermined range. Thereby, the magnitude of the acceleration B of the vehicle 1 at each time point is limited according to the battery temperature T.
Therefore, the control of the vehicle system VS1 of the first embodiment executed by the ECU 60 will be described in detail below with reference to the flowchart (main routine MR1) of FIG.
Note that a threshold value A of the control value C is stored in advance in a ROM (not shown) in the microcomputer 61 of the ECU 60. This threshold A is a value set in consideration of the results of the above-described running test and the target life of the battery 11 in the vehicle 1, for example.

First, in the main routine MR1, when the operation of the vehicle 1 is started (key-on) (YES in step S1), the process proceeds to step S2.
In step S2, the temperature sensor 50 and the acceleration sensor 40 are used to measure the battery temperature T of the battery 11 and the acceleration B in the speed increasing direction of the vehicle 1, respectively. Note that steps S2 to S8 are repeated at a predetermined cycle time TC (for example, every 0.1 second) until the vehicle 1 is keyed off.

Subsequently, in step S3, it is determined whether or not a control value C given by C = acceleration B / battery temperature T is equal to or greater than a threshold value A. As the threshold A, a value stored in advance in the microcomputer 61 is used.
If YES, that is, if the control value C is greater than or equal to the threshold value A (C ≧ A), the process proceeds to step S4 to determine whether or not the battery 11 (the assembled battery 10) is being discharged. On the other hand, if NO, that is, if the control value C is smaller than the threshold value A (C <A), steps S4 to S6 are skipped and the process proceeds to step S7.

Since the vehicle 1 is a hybrid vehicle as described above, the vehicle 1 is accelerated and the acceleration B in the acceleration direction is generated in the vehicle 1 so that the control value C becomes equal to or greater than the threshold value A. Is driving the wheel 110 via the speed reducer 100, the motor 20 is driving the wheel 110 by the discharge power discharged by the battery 11 (the assembled battery 10), and the engine 30 and the battery 11 ( There is a case where the wheel 110 is driven by the motor 20).
In this step S4, YES, that is, when the battery 11 is discharged, it is considered that the vehicle 1 is accelerated by driving the motor 20 by at least the electric energy discharged from the battery 11 (the assembled battery 10). 11 is limited (step S5). Specifically, the discharge power value is limited to an upper limit value corresponding to the battery temperature T. By limiting the discharge power of the battery 11 in this way, the output of the motor 20 is reduced, and the acceleration B is limited so that the control value C becomes smaller than the threshold value A.

On the other hand, in step S4, if the vehicle 1 is accelerating, that is, if the battery 11 is not discharged, the vehicle 1 is considered to be accelerating by driving the engine 30. Therefore, the amount of fuel injected from the injector of the engine 30 is limited (step S6). By limiting the injection amount in this way, the output of the engine 30 is reduced, and the acceleration B is limited so that the control value C becomes smaller than the threshold value A.
In addition, after step S5 and step S6, it progresses to step S7.

In step S7, it is determined whether or not the vehicle 1 is keyed off. Here, if NO, the process proceeds to step S8, while if YES, the process ends.
In step S8, it is determined whether or not a predetermined cycle time TC (0.1 second) has elapsed from the measurement of the battery temperature T of the battery 11 and the acceleration B of the vehicle 1 performed in step S2.
If NO, that is, if the predetermined cycle time TC has not elapsed since the previous measurement, the process returns to step S7 and repeats steps S7 and S8 (that is, waits until the cycle time TC elapses). On the other hand, if YES, that is, if the cycle time TC has elapsed from the measurement in step S2, the process returns to step S2, and steps S2 to S8 are repeated.

  In the first embodiment, the motor 20 and the engine 30 correspond to the power source, the acceleration sensor 40 corresponds to the acceleration detection means, the temperature sensor 50 corresponds to the battery temperature detection means, and steps S3 to S6 correspond to the acceleration limiting means. .

In the vehicle system VS1 according to the first embodiment, the control value C determined to have a relationship in which the influence of the increase in the acceleration B in the vehicle 1 and the influence of the increase in the battery temperature T in the battery 11 (the assembled battery 10) conflict. Used, there are steps S3 to S6 for limiting the magnitude of the acceleration B of the vehicle 1 so that the control value C satisfies a predetermined range (in the first embodiment, the threshold A or less). For example, the control value C changes in the same direction when the acceleration B in the acceleration direction, which is the direction in which the high-rate deterioration of the battery 11 progresses, is increased and when the battery temperature T is decreased. Integrating two contradictory parameters (acceleration B and battery temperature T) enables control using one control value C. Therefore, control is easy.
Moreover, according to the vehicle system VS1, the discharge of a large discharge power (generation of high rate discharge) from the battery 11 (the assembled battery 10) accompanying the rapid acceleration of the vehicle 1 is limited according to the battery temperature T, and the battery 11 High-rate deterioration of (assembled battery 10) is prevented. In particular, when the battery temperature T at which deterioration is likely to occur is low, the magnitude of the acceleration B is easily limited, so that high-rate deterioration of the battery 11 can be appropriately prevented.

  Steps S3 to S6 give the control value C at C = B / T, and limit the magnitude of the acceleration B so that the control value C satisfies C <A with respect to a predetermined threshold A. Thus, high rate deterioration of the battery 11 can be reliably prevented.

  In addition, since the battery 11 is a lithium ion secondary battery that is a non-aqueous electrolyte secondary battery in which diffusion rate control is likely to occur, high rate deterioration that occurs in the battery 11 can be reliably prevented.

(Modification 1)
Next, modification 1 of the present invention will be described with reference to the drawings.
In the first embodiment, the threshold value A is a constant value. In contrast, the vehicle system VS2 according to the first modification includes threshold setting means for setting the threshold A to a smaller value as the battery deterioration progresses, and deterioration detection means for detecting the degree of battery deterioration. This is different from the first embodiment described above.
Therefore, differences from the first embodiment will be mainly described, and description of the same parts as those of the first embodiment will be omitted or simplified. In addition, about the same part as Embodiment 1, the same effect is produced. In addition, the same contents are described with the same numbers.

First, a vehicle 201 to which the vehicle system VS2 according to the first modification is applied will be described with reference to FIG.
Similar to the vehicle 1 of the first embodiment, the vehicle 201 includes a battery pack 10, a motor 20, an engine 30, an acceleration sensor 40, and a temperature sensor 50, each of which includes a plurality (60) of lithium ion secondary batteries 11 and 11. In addition, the ECU 260 includes a voltage sensor 210 and a current sensor 220.
The vehicle system VS2 is realized by a program executed by the ECU 260.

In the vehicle 201 described above, the voltage sensor 210 is a known voltmeter installed so as to be able to measure the voltage V between the positive electrode and the negative electrode of the battery 11. The current sensor 220 is a known DC current sensor installed so that the magnitude of the DC current flowing through the battery 11 (the assembled battery 10) can be measured.
The ECU 260 includes a CPU, a ROM, and a RAM (not shown), and has a microcomputer 261 that operates according to a predetermined program.

The ROM of the microcomputer 261 includes a plurality of threshold values used as the threshold value A (first threshold value A1, second threshold value A2, and third threshold value A3), and a first internal resistance threshold value R1 used for selecting the plurality of threshold values. A second internal resistance threshold value R2 is stored in advance.
The first threshold value A1, the second threshold value A2, and the third threshold value A3 have a relationship of A3 <A2 <A1. The first threshold value A1, the second threshold value A2, and the third threshold value A3 are selected as the threshold value A of the control value C according to the magnitude of the internal resistance R of the battery 11. Specifically, when the internal resistance R of the battery 11 is equal to or less than the first internal resistance threshold R1 (R ≦ R1), the first threshold A1 is selected as the threshold A of the control value C. When the internal resistance R is greater than the first internal resistance threshold R1 and equal to or less than the second internal resistance threshold R2 (R1 <R ≦ R2), the second threshold A2 is selected. Furthermore, when the internal resistance R is larger than the second internal resistance threshold R2 (R> R2), the third threshold A3 is selected. Thereby, as the internal resistance R of the battery 11 increases (as the deterioration progresses), the threshold A is set to a smaller value, so that the control value C is limited to a smaller value. The first threshold value A1 is assigned in advance as the initial value of the threshold value A.

Next, the control of the vehicle system VS2 of the first modification will be described in detail below with reference to the flowcharts of FIGS. 4 and 5 (main routine MR2 and R detection subroutine S30).
First, in the main routine MR2, when the operation of the vehicle 201 is started (key-on) (YES in step S1), the process proceeds to step S21.
In this step S21, using the temperature sensor 50, the acceleration sensor 40, the current sensor 220, and the voltage sensor 210, the battery temperature T of the battery 11 at that time, the acceleration B in the speed increasing direction of the vehicle 201, and the current value of the battery 11 I and the inter-terminal voltage V are measured.

Subsequently, in step S22, it is determined whether or not the timing for detecting the internal resistance R of the battery 11 has come. Specifically, for example, at least 3 months after the assembled battery 10 (battery 11) is mounted on the vehicle 201, or at least 3 months since the last time the internal resistance R was detected and stored in the microcomputer 261 Is the timing for detecting the internal resistance R.
If YES, that is, when it is time to detect the internal resistance R, the process proceeds to the R detection subroutine of step S30. On the other hand, if NO, that is, if the timing for detecting the internal resistance R has not come, the process proceeds to step S3.

Next, the R detection subroutine S30 will be described with reference to FIG.
First, in step S31, it is determined whether or not the vehicle 201 is in a condition that allows the internal resistance R to be detected. Specifically, for example, the vehicle 201 is stopped and the battery 11 (the assembled battery 10) is not charged or discharged.
If YES, that is, if the vehicle 201 is in a condition where the internal resistance R can be detected, the process proceeds to step S32. On the other hand, if NO, that is, if the vehicle 201 is not in a condition that can detect the internal resistance R, the R detection subroutine S30 is terminated, the process returns to the main routine MR2, and the process proceeds to step S3.

  In step S32, the internal resistance R of the battery 11 is detected. Specifically, the internal resistance R of the battery 11 is detected using, for example, a known direct current resistance (DC-IR) measurement method (or a method simulating it). The detected internal resistance R is stored in the RAM of the microcomputer 261.

Next, in step S33, it is determined whether or not the detected internal resistance R of the battery 11 is equal to or less than the first internal resistance threshold value R1 described above.
If YES, that is, if the internal resistance R is equal to or less than the first internal resistance threshold value R1, the process proceeds to step S34, and the first threshold value A1 is substituted for the threshold value A of the control value C. On the other hand, if NO, that is, if the internal resistance R is greater than the first internal resistance threshold value R1, the process proceeds to step S35.

In step S35, it is determined whether or not the internal resistance R of the battery 11 is equal to or less than the second internal resistance threshold value R2.
If YES, that is, if the internal resistance R is greater than the first internal resistance threshold value R1 and equal to or less than the second internal resistance threshold value R2, the process proceeds to step S36, and the second threshold value A2 is substituted for the threshold value A of the control value C. On the other hand, if NO, that is, if the internal resistance R is larger than the second internal resistance threshold R2, the process proceeds to step S37, and the third threshold A3 is substituted for the threshold A of the control value C.
In addition, after step S34, step S36, and step S37, it returns to main routine MR2, and progresses to step S3.

Steps S3 to S8 are the same as those in the first embodiment, and a description thereof will be omitted. However, the control value C is controlled according to the value substituted for the threshold A. For example, when the first threshold value A1 is substituted for the threshold value A (step S34), the acceleration B is limited so that the control value C is smaller than the first threshold value A1.
When the second threshold value A2 having a value smaller than the first threshold value A1 is substituted for the threshold value A, the acceleration B is higher than when the first threshold value A1 is used so that the control value C is smaller than the second threshold value A2. Is further limited.
In this way, when the deterioration of the battery 11 progresses and the internal resistance R increases, the threshold value A of the control value C is controlled to be smaller, and the progress rate of the high-rate deterioration of the battery 11 is suppressed to a lower level. Can do.

  In the first modification, steps S33 to S37 correspond to threshold setting means, and S32 corresponds to deterioration detection means.

  As described above, the vehicle system VS <b> 2 according to the first modification includes steps S <b> 33 to S <b> 37 that set the threshold value A to a smaller value as the deterioration of the battery 11 progresses. For this reason, the control value C is controlled to be smaller as the deterioration of the battery 11 progresses. Therefore, the progress speed of the deterioration of the battery 11 can be further suppressed as the deterioration of the battery 11 progresses.

  Moreover, it has step S32 which detects the grade of deterioration of the battery 11, and the threshold value A is set to a smaller value as the internal resistance R of the battery 11 detected in step S32 is larger. For this reason, this vehicle system VS2 itself can detect the degree of deterioration of the battery 11 and set the threshold A. Therefore, the vehicle system VS2 itself can appropriately suppress the progress speed of the deterioration of the battery 11 according to the degree of the deterioration of the battery 11, and can sufficiently draw out the characteristics of the battery 11.

In the above, the present invention has been described according to the first embodiment and the first modified embodiment. However, the present invention is not limited to the above-described embodiment, and can be applied with appropriate modifications without departing from the gist thereof. Needless to say.
For example, in Embodiment 1 or the like, a hybrid vehicle is used as a vehicle, but the present invention may be applied to, for example, an electric vehicle (EV) that is driven only by a motor.
In the first embodiment, the limit value C is calculated as C = B / T using the vehicle acceleration B and the battery temperature T. However, for example, as the control value C, C = mB−nT (m and n are positive constants), C = B / T ² or the like can be used.

1,201 Vehicle 11 Secondary battery 20 Motor (drive source)
30 engine (drive source)
40 Acceleration sensor (acceleration detection means)
50 Temperature sensor (battery temperature detection means)
A threshold value B acceleration C control value T battery temperature VS1, VS2 vehicle system

Claims (5)

A secondary battery mounted on the vehicle;
A power source for driving the vehicle,
A vehicle system that controls a vehicle including a power source including a motor that performs powering by electric energy from the secondary battery,
Acceleration detecting means for detecting acceleration in the acceleration direction of the vehicle;
Battery temperature detection means for detecting the battery temperature of the secondary battery, and
It is obtained using the acceleration in the acceleration direction detected by the acceleration detection means and the battery temperature detected by the battery temperature detection means, and the influence of the increase in acceleration and the influence of the increase in battery temperature are contradictory. The vehicle system which has an acceleration limiting means which restrict | limits the magnitude | size of the acceleration of the said acceleration direction so that the control value defined in the relationship may satisfy the predetermined range. The vehicle system according to claim 1,
The acceleration is B,
When the battery temperature is T,
The acceleration limiting means includes
The control value C is given by C = B / T,
A vehicle system that limits the magnitude of the acceleration such that the control value C is C <A with respect to a predetermined threshold A. The vehicle system according to claim 2,
Threshold setting means for setting the threshold A,
The vehicle system which has a threshold value setting means which sets the said threshold value A to a small value, so that deterioration of the said secondary battery progresses. The vehicle system according to claim 3,
Having a deterioration detecting means for detecting the degree of deterioration of the secondary battery,
The threshold setting means includes
The vehicle system which sets the said threshold value A to a small value, so that the degree of the said deterioration detected by the said deterioration detection means is large. The vehicle system according to any one of claims 1 to 4, wherein
The vehicle system, wherein the secondary battery is a non-aqueous electrolyte type secondary battery.

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