JP2012147574A - Amount-of-charge display device - Google Patents

Abstract

The present invention realizes a charge amount display capable of suppressing a driver from feeling uncomfortable even when a target value of a charge amount of a battery is changed according to a driving situation of a vehicle.
A charge amount display device is mounted on a vehicle including a battery. The charge amount display device includes a charge amount display means 11 and 13 for displaying an absolute value of the charge amount of the battery to the vehicle driver, a driving state of the vehicle, and a charge amount displayed by the charge amount display means. And a target value display means 11 and 13 for displaying the calculated target value for the driver of the vehicle.
[Selection] Figure 1

Description

  The present invention relates to a technical field of a charge amount display device for notifying a driver of an amount of electric power stored in a battery in a vehicle such as a hybrid vehicle or an electric vehicle.

  As this type of device, for example, the remaining capacity for display is calculated for each predetermined cycle based on the usable range of the power storage device, and when the upper limit or lower limit of the usable range is changed, gradually over a plurality of cycles. There has been proposed an apparatus for changing the display so as to approach the remaining display capacity corresponding to the usable range after the change (see Patent Document 1).

  In a vehicle equipped with this type of device, for example, the management target value of the state of charge of the power storage unit is varied depending on, for example, the traveling speed of the vehicle, thereby improving the capacity of the power storage unit in operation. (See Patent Document 2). Alternatively, by referring to a battery current detected based on an output signal from a current sensor provided between the battery and the motor / generator, a map determined in advance based on the battery temperature and the degree of deterioration of the battery. The battery capacity is determined by integrating the multiplication values (ie, battery current × correction coefficient) obtained by multiplying the calculated correction coefficient (see Patent Document 3).

JP 2010-110187 A JP-A-11-164402 JP 2002-340996 A

  However, according to Patent Document 1 described above, the remaining capacity displayed varies depending on the usable range, so that the behavior of the memory indicating the remaining capacity is not stable, and the driver may feel uncomfortable. There is a problem. In the techniques described in Patent Documents 2 and 3, it is extremely difficult to solve the technical problem.

  The present invention has been made in view of the above technical problems, for example, and even when the target value of the charge amount of the battery is changed according to the driving state of the vehicle, the driver feels uncomfortable. It is an object of the present invention to propose a charge amount display device capable of realizing a charge amount display capable of suppressing the above.

  In order to solve the above problems, a charge amount display device according to the present invention is mounted on a vehicle including a battery, and a charge amount display means for displaying an absolute value of the charge amount of the battery to a driver of the vehicle. A calculation means for calculating a target value of the charge amount based on the driving status of the vehicle and an absolute value of the charge amount displayed by the charge amount display means, and the calculation for the driver of the vehicle. Target value display means for displaying the set target value.

  The charge amount display device of the present invention is mounted on a vehicle including a battery such as a lithium ion battery or a nickel metal hydride battery. The vehicle may be an electric vehicle using only a battery as a power source, or may be a hybrid vehicle using a battery and an engine as power sources.

  For example, the charge amount display means including a memory, a processor, etc. displays the absolute value of the charge amount of the battery to the driver of the vehicle. Specifically, for example, the charge amount display means detects the charge amount of the battery based on the current value of the battery measured by an ammeter or the like, and the absolute value of the detected charge amount is displayed on a liquid crystal monitor or the like. By displaying on the display unit, the absolute value of the charge amount is notified to the driver.

  For example, the calculation means comprising a memory, a processor, etc. is based on, for example, the vehicle speed, acceleration, deceleration, driving conditions on the hill, etc., and the absolute value of the charge amount displayed by the charge amount display means. Then, the target value of the charge amount is calculated. In addition, for example, an electronic control unit of a vehicle such as an ECU (Electronic Control Unit: ECU) uses, for example, a generator or the like so that the amount of charge of the battery varies around the calculated target amount of charge. Control.

  For example, the target value display means including a memory, a processor, etc. displays the calculated target value to the driver of the vehicle.

  Here, according to the inventor's research, the following matters have been found. That is, in an electric vehicle or a hybrid vehicle, for example, when control that changes the target value of the battery charge amount according to the vehicle speed or the like is adopted or applied, the fuel gauge that displays only the absolute value of the battery charge amount Then, for example, the position of the needle or the like deviates from the median value of the fuel gauge relatively frequently. For example, the driver misunderstands that the driving efficiency is low although the driving is actually efficient. there is a possibility. On the other hand, by displaying the charge amount as a relative value, the target value of the charge amount can always be the center of the fuel gauge, but the behavior of the fuel gauge does not match the behavior of the actual charge amount Therefore, the driver may feel uncomfortable.

  Therefore, in the present invention, the absolute value of the charge amount of the battery is displayed by the charge amount display means, and the calculated target value is displayed by the target value display means. For this reason, the behavior of the displayed charge amount and the behavior of the actual charge amount can be matched, and the possibility of misunderstanding by the driver can be suppressed.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a block diagram which shows an example of a structure of the vehicle by which the charge amount display apparatus which concerns on embodiment of this invention is mounted. It is a conceptual diagram which shows an example of the residual amount display displayed by the charge amount display apparatus which concerns on embodiment of this invention. It is a conceptual diagram which shows an example of the residual amount display displayed by the charge amount display apparatus which concerns on a comparative example. It is a conceptual diagram which shows the other example of the residual amount display displayed by the charge amount display apparatus which concerns on a comparative example. It is a conceptual diagram which shows another example of the residual amount display displayed by the charge amount display apparatus which concerns on embodiment of this invention.

  Hereinafter, an embodiment according to a charge amount display device of the present invention will be described with reference to the drawings.

  First, the configuration of a vehicle on which the charge amount display device according to this embodiment is mounted will be described with reference to FIG. FIG. 1 is a block diagram illustrating an example of a configuration of a vehicle on which the charge amount display device according to the present embodiment is mounted. A solid line in FIG. 1 represents a mechanical connection, and a broken line represents an electrical connection. In FIG. 1, only members directly related to the present embodiment are shown, and the other members are not shown.

  In FIG. 1, a vehicle 10 includes an ECU 11, a battery 12, a display unit 13, and a motor / generator 14. Here, the vehicle 10 may further include an engine (that is, the vehicle 10 may be a hybrid vehicle) or may not include an engine (that is, the vehicle 10 may be an electric vehicle). Good).

  The battery 12 is, for example, a lithium ion battery, a nickel metal hydride battery, or the like, and the inter-terminal voltage is a relatively high voltage, such as 200 V (volts). The battery 12 can supply power to the motor / generator 14 and can be charged by regenerative power of the motor / generator 14.

  The display unit 13 is, for example, a liquid crystal display, and is disposed in, for example, an instrument panel. The display unit 13 may display not only the charging state (State of Charge: SOC) of the battery 12 described later, but also the speed of the vehicle 10, for example.

  The motor / generator 14 can generate a driving force with electric power supplied from the battery 12 and can generate regenerative electric power. The generated driving force is transmitted to the driving wheel W through a power transmission mechanism.

  The ECU 11 as a part of the charge amount display device 100 mounted on the vehicle 10 configured as described above (i) displays the absolute value of the charge amount of the battery 12 to the driver of the vehicle 10, and (ii) ) Calculate the target value of the charge amount of the battery 12 based on the driving situation of the vehicle 10 and the absolute value of the displayed charge amount; (iii) The calculated target value is given to the driver of the vehicle 10 indicate.

  Specifically, the ECU 11 as a part of the charge amount display device 100 includes a display unit 13 for informing the driver of the vehicle 10 of the absolute value of the charge amount of the battery 12 and the target value of the charge amount. On the top, for example, an SOC meter as shown in FIG. 2 is displayed. FIG. 2 is a conceptual diagram illustrating an example of a remaining amount display displayed by the charge amount display device according to the present embodiment.

  In FIG. 2, the SOC meter includes a meter 210 that indicates the absolute value of the charge amount of the battery 12 and a bar 220 that indicates the target value of the charge amount calculated by the ECU 11. In the SOC meter shown in FIG. 2, the target value of the charge amount is indicated by the needle 221 displayed on the bar 220.

  As described above, the target value of the charge amount is calculated by the ECU 11 based on the driving state of the vehicle 10 and the displayed absolute value of the charge amount. Various known methods can be applied to the method for detecting the absolute value of the amount of charge of the battery 12 and the method for calculating the target value of the amount of charge, and the details thereof will not be described here.

  This is for the following reason. That is, the SOC of the battery of the conventional vehicle is always controlled to be constant (for example, to maintain 60% of full charge). However, for example, when the vehicle decelerates from high speed travel at 100 km / h, only 40% of the battery charge due to regenerative braking can be secured until full charge, so the excess is released as heat by the mechanical brake. Inevitably, energy efficiency may be reduced. On the other hand, when the vehicle is accelerated from a stopped state or running at a low speed, only 60% of the battery capacity can be utilized until complete discharge, and it is difficult to fully utilize the battery's inherent charge capacity.

  Therefore, in the present embodiment, the target value of the charge amount is calculated according to the driving state of the vehicle 10 and the SOC of the battery 12, and the SOC of the battery 12 is managed according to the calculated target value, so that the energy The efficiency can be improved and the charging capacity of the battery 12 can be fully utilized.

  The “ECU 11” according to the present embodiment is an example of “charge amount display means”, “calculation means”, and “target value display means” according to the present invention. In the present embodiment, a part of the functions of the ECU 11 for various electronic controls of the vehicle 10 is used as a part of the charge amount display device 100.

<Comparative example>
Here, the charge amount display apparatus according to the comparative example will be described with reference to FIGS. 3 and 4. FIG. 3 is a conceptual diagram illustrating an example of the remaining amount display displayed by the charge amount display device according to the comparative example, and FIG. 4 is another example of the remaining amount display displayed by the charge amount display device according to the comparative example. It is a conceptual diagram which shows an example.

  As shown in FIG. 3, when only the meter 410 that displays the battery charge amount as an absolute value is displayed, control is performed in which the target value of the battery charge amount is changed according to the driving state of the vehicle or the like. The charge amount in meter 410 (second scale in FIG. 3) deviates relatively frequently from the median value (five scale in FIG. 3), so that the operation efficiency is actually improved despite the fact that the operation is efficient. There is a possibility that the driver will misunderstand that it is bad.

  On the other hand, as shown in FIG. 4, when only the meter 420 that displays the charge amount of the battery as a relative value with respect to the target value of the charge amount is displayed, the target value of the charge amount of the battery depends on the driving situation of the vehicle, etc. Even if the control to be changed is executed, it is possible to always set the target amount of charge to the center of the meter 420, but the behavior of the meter 420 does not match the behavior of the actual charge amount. May feel uncomfortable. Specifically, for example, even when the vehicle is decelerated from 100 km / h to 0 km / h (ie, stop), three scales are added for a target value for a certain charge amount, and four scales are used for target values for other charge amounts. There may be an increase in equality.

  Returning to FIG. 2 again, in the charge amount display device 100 according to this embodiment, a meter 210 indicating the absolute value of the charge amount of the battery 12 and a bar 220 indicating the target value of the charge amount are displayed on the display unit 13. The For this reason, the behavior of the displayed charge amount and the behavior of the actual charge amount can be matched, and the possibility of misunderstanding by the driver can be suppressed.

<Modification>
A modification of the charge amount display device 100 according to the present embodiment will be described with reference to FIG. FIG. 5 is a conceptual diagram illustrating another example of the remaining amount display displayed by the charge amount display device according to the present embodiment.

  As shown in FIG. 5, the SOC meter 300 according to this modification is a pointer-type meter. In FIG. 5, a needle 310 indicates an absolute value of the charge amount of the battery 12, and a needle 320 indicates a target value of the charge amount.

  The present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The apparatus is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... ECU, 12 ... Battery, 13 ... Display part, 14 ... Motor generator, 100 ... Charge amount display apparatus, W ... Drive wheel

Claims (1)

Mounted in a vehicle with a battery,
Charge amount display means for displaying an absolute value of the charge amount of the battery for the driver of the vehicle;
Calculation means for calculating a target value of the charge amount based on the driving status of the vehicle and the absolute value of the charge amount displayed by the charge amount display means;
Target value display means for displaying the calculated target value for the driver of the vehicle;
A charge amount display device comprising:

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