JP7139071B2 - Automotive controller - Google Patents

Description

The present invention relates to an in-vehicle control device.

In recent years, a telematics device has been provided as a wireless communication device mounted on a vehicle. A telematics device is a device that performs data communication with an information system outside the vehicle using mobile wireless data communication, the Internet, a satellite positioning system, etc., in order to provide various information and services to the vehicle.

Japanese Patent Application Laid-Open No. 2003-278418

A telematics device operates by being supplied with electric power from a main battery (auxiliary battery) mounted on a vehicle. Therefore, when the engine is cranked, the voltage of the main battery temporarily drops significantly due to the operation of the starter, and the voltage supplied to the telematics device falls below the predetermined lower limit of operable voltage, causing the telematics device to reset (initialize). ).

SUMMARY OF THE INVENTION It is an object of the present invention to provide an in-vehicle control device capable of suppressing resetting of a telematics device due to a drop in voltage of a main battery.

In order to achieve the above object, an in-vehicle control device according to the present invention is an in-vehicle control device mounted in a vehicle including a main battery and an electric motor receiving electric power from the main battery to drive an engine. A telematics device that normally operates at a predetermined operable voltage or higher by incorporating a control unit powered by the main battery and a backup battery that is charged by the power supplied by the main battery and supplies power to the control unit. and reverse current prevention means for passing current in one direction from the main battery to the telematics device and blocking current in the opposite direction.

According to this configuration, since the telematics device has a built-in backup battery, even if the current supplied to the electric motor increases when the engine is started (during cranking) and the voltage of the main battery drops significantly, The voltage supplied to the control unit is ensured. Therefore, resetting of the telematics device due to a drop in the voltage of the main battery can be suppressed.

Also, the reverse current prevention means can prevent power from being taken out from the backup battery to the electric motor. Moreover, since power can be continuously supplied in one direction from the main battery to the backup battery, unlike a configuration in which the main battery and the backup battery are simply disconnected, the backup battery may not be fully charged. can be suppressed.

The reverse current prevention means may be built in the telematics device or may be provided outside the telematics device.

Also, the on-vehicle control device according to the present invention is particularly suitable for vehicles employing idling stop (IDS) control for stopping the engine when it is not needed. That is, when the engine is restarted (returned from the idling stop state) due to the establishment of a predetermined restart condition, it is possible to prevent the telematics device from being reset due to power shortage, and to ensure the normal operation of the telematics device.

According to the present invention, resetting of the telematics device due to a drop in the voltage of the main battery can be suppressed.

1 is a block diagram showing the configuration of a vehicle equipped with an in-vehicle control device according to an embodiment of the present invention; FIG. It is a figure which shows an example of the time change of the voltage of a vehicle battery.

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Main parts of the vehicle>
FIG. 1 is a block diagram showing the configuration of a vehicle 1 equipped with an in-vehicle control device according to one embodiment of the present invention.

A vehicle 1 includes a vehicle battery (main battery) 2 that supplies electric power to an electrical load such as an auxiliary device, and a starter motor 3 that receives power from the vehicle battery 2 and cranks the engine. The vehicle battery 2 is composed of, for example, a DC 12 V (volt) lead battery.

A vehicle 1 is equipped with a TCU (Telematics Communication Unit) 4 . The TCU 4 is a device that performs data communication with an information system outside the vehicle using mobile wireless data communication, the Internet, a satellite positioning system, etc., in order to provide various information and services to the vehicle 1 .

The TCU 4 is provided with a power supply line 11 to which voltage is supplied from the vehicle battery 2 . The power supply line 11 is connected to the power supply IC 12 . The power supply IC 12 is a switch IC for switching between supply and stop of power supply to the load 13 built in the TCU 4 . It should be noted that the power supply line 11 may be connected to a load by interposing a power supply IC in addition to the power supply IC 12 . The load 13 integrates functions such as a communication IC that communicates with the inside and outside of the vehicle, an antenna for mobile wireless data communication, and an antenna that receives radio waves from GNSS (Global Navigation Satellite System) satellites. This includes telematics antennas.

A reverse current prevention diode 14 is interposed in the power supply line 11 . The reverse current prevention diode 14 passes current in one direction from the vehicle battery 2 to the power supply IC 12 and blocks current in the opposite direction.

The TCU 4 is also provided with a BUB (Back Up Battery) 21 and a booster circuit 22 . The BUB 21 is a backup power supply that supplies power to each part of the TCU 4 when the power supply from the vehicle battery 2 is cut off. BUB 21 is connected to the input side of booster circuit 22 . The output side of the booster circuit 22 is connected to the portion of the power supply line 11 between the reverse current prevention diode 14 and the power supply IC 12 via the reverse current prevention diode 23 . The reverse current prevention diode 23 passes current from the booster circuit 22 to the power supply line 11 and blocks reverse current.

One end of a charging line 25 is connected to a power feeding line 24 from the power supply IC 12 to the load 13 . The other end of charging line 25 is connected to BUB 21 . A charging IC 26 is interposed in the charging line 25 . The charging IC 26 switches between supplying and stopping the charging current flowing through the charging line 25 to the BUB 21 . Also, the charging IC 26 controls the booster circuit 22 to switch between discharging and stopping the BUB 21 . A discharge voltage (output voltage) from the BUB 21 is boosted by the booster circuit 22 and supplied to the power supply line 11 .

<Voltage drop prevention treatment>
FIG. 2 is a diagram showing an example of a time change of the voltage of the vehicle battery 2. As shown in FIG.

While the ignition switch of the vehicle 1 is turned on (IG-ON), the charging IC 26 A/D-converts the voltage of the power supply line 11 into a digital value at a constant detection cycle, thereby increasing the voltage of the vehicle battery 2 ( BAT voltage) is detected.

In order to start the engine of the vehicle 1, electric power is supplied from the vehicle battery 2 to the starter motor 3, and when the starter motor 3 operates (ST-ON), the voltage of the vehicle battery 2 (BAT voltage) drops sharply and greatly. .

When the detected value of the voltage of the vehicle battery 2 drops to the BUB supply start voltage, the charging IC 26 controls the booster circuit 22 to start discharging from the BUB 21 and boost the discharge voltage to the operating voltage of the power supply IC 12 or higher. . The BUB supply start voltage is set to a value higher than the operable voltages of the power supply IC 12 and the charging IC 26 . As a result, in response to the detected value of the voltage of the vehicle battery 2 dropping to the BUB supply start voltage, discharge from the BUB 21 is started, thereby maintaining the voltage of the power supply line 11 at or above the BUB supply start voltage. can be done.

<Effect>
As described above, since the BUB 21 is built in the TCU 4, even if the current supplied to the starter motor 3 increases when the engine is started (during cranking) and the voltage of the vehicle battery 2 drops significantly, The voltage supplied to the power supply IC 12 and the like is ensured. Therefore, resetting of the TCU 4 due to a drop in the voltage of the vehicle battery 2 can be suppressed.

In addition, the reverse current prevention diode 14 can prevent electric power from being taken out from the BUB 21 to the starter motor 3 . Moreover, since electric power can be continuously supplied in one direction from the vehicle battery 2 to the BUB 21, unlike the configuration in which the vehicle battery 2 and the BUB 21 are simply cut off, the BUB 21 is prevented from being sufficiently charged. can be suppressed.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, reverse current prevention diode 14 may be provided outside TCU 4 .

In addition, although the starter motor 3 is taken up as an example of the electric motor, a configuration including a motor generator directly connected to the engine instead of the starter motor 3, or an ISG (integrated starter generator) used for driving assistance ), the present invention can also be applied to a configuration provided with

In addition, various design changes can be made to the above configuration within the scope of the matters described in the claims.

1: Vehicle 2: Vehicle battery (main battery)
3: Starter motor (electric motor)
4: TCU (Telematics Unit)
12: Power supply IC (control unit)
14: reverse current prevention diode (reverse current prevention means)
26: Charging IC (control unit)

Claims (2)

An in-vehicle control device mounted in a vehicle including a main battery and an electric motor receiving power supply from the main battery to drive an engine,
A control unit supplied with power from the main battery, a backup battery charged with the power supplied from the main battery and supplying power to the control unit , and a booster circuit boosting the discharge voltage from the backup battery are incorporated. and a telematics device that normally operates at a predetermined operable voltage or higher;
a first reverse current prevention means which is interposed in a power supply line from the main battery to the control unit to allow current to flow in one direction from the main battery to the telematics device and block current in the opposite direction ;
a second reverse current prevention means for passing a current from the booster circuit to the power supply line and blocking a reverse current ;
The input side of the booster circuit is connected to the backup battery, and the output side of the booster circuit is connected to the first reverse current prevention means in the power supply line and the control section via the second reverse current prevention means. In-vehicle controller connected to the part between The electric motor is connected to the power supply line,
2. The in-vehicle control according to claim 1, wherein said first reverse current prevention means is interposed downstream in one direction from said main battery toward said telematics device from a connecting portion of said electric motor in said power supply line. Device.

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