JP2008302822A - State detecting method of in-vehicle battery, power supply control method, state detecting device of in-vehicle battery, and power supply control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-vehicle battery state detecting method for detecting an in-vehicle battery state at a low component cost without using a current sensor. <P>SOLUTION: While the number of revolutions of an engine is lower than the predetermined number of revolutions (S5), an input terminal voltage of distributing equipment is sequentially detected (S9). The detected input terminal voltage value and a generating voltage instruction value are sequentially compared with each other (S11), and the generating voltage instruction value is repeatedly changed (S7) so that the input terminal voltage value and the generating voltage instruction value are matched with each other (S13). An open circuit voltage of the in-vehicle battery is found (S15) based on an input terminal voltage value when the input terminal voltage value and the generating voltage value instruction value are matched with each other (S13), and based on the found open circuit voltage value, the state of the in-vehicle battery is detected (S17, 19). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention uses an output voltage of an on-vehicle generator that controls an output voltage by a regulator, generates power in conjunction with an engine, supplies the generated power to a plurality of electric loads through a power distribution device, and charges a battery. The present invention relates to an in-vehicle battery state detection method, a power supply control method, an in-vehicle battery state detection device, and a power supply control device.

  The number of electrical components mounted on vehicles is increasing steadily in terms of safety, convenience, comfort, and product power. Large-capacity electric loads such as wind defoggers and seat heaters for cold regions are adopted, and equipment that has been operated with hydraulic pressure or engine power is electrified to improve control performance and efficiency. It is out. Electric loads such as an electric brake and an electric power steering device (EPS) that require high reliability are also adopted, and the importance of the power supply device of the vehicle is only increasing.

In Patent Document 1, the amount of power generated by the vehicle generator is controlled based on a control signal input from the outside, and it is monitored whether or not the output voltage of the vehicle generator is included in the monitoring range. A vehicle power generation control device that prohibits control based on a control signal and controls a power generation voltage using a target value included in the monitoring range when out of the monitoring range is disclosed.
JP 2006-156619 A

  In a power supply device equipped with an in-vehicle generator and an in-vehicle battery, it is not easy to detect the state of the in-vehicle battery because a polarization phenomenon is attached to the in-vehicle battery. Conventionally, a current sensor is attached to the in-vehicle battery. Various methods have been considered, such as integrating input and output currents. However, in the method of integrating the input / output current using the current sensor, there is also a natural discharge of the in-vehicle battery, etc. There is also a problem that it is possible to suddenly encounter a battery exhaustion condition without notice.

The present invention has been made in view of the circumstances as described above, and in the first invention, the state of the in-vehicle battery that can detect the state of the in-vehicle battery without using a current sensor and at a low component cost. It aims to provide a method.
In the second invention, an object of the present invention is to provide a power supply control method capable of avoiding a battery run-up state based on the state of the in-vehicle battery detected by the in-vehicle battery state detection method according to the first invention.

In the third invention, an object of the present invention is to provide an in-vehicle battery state detection device that can detect the state of an in-vehicle battery without using a current sensor and at a low component cost.
In the fourth invention, an object of the present invention is to provide a power supply control device that includes the on-vehicle battery state detection device according to the third invention and that can avoid a battery-up state based on the state of the on-vehicle battery detected by the state detection device. .

  The electric power generated by the in-vehicle generator is distributed to each electric load through a power distribution box (distribution device), but due to the harness resistance between the in-vehicle generator and the power distribution box, the terminal voltage value of the in-vehicle generator is It is not the same as the terminal voltage value (= battery terminal voltage value) of the power distribution box. As shown in FIGS. 2A and 2B, the terminal voltage value of the power distribution box is lower than the terminal voltage value of the in-vehicle generator as the generated current of the in-vehicle generator increases, and the harness resistance is known. For example, as shown in FIG. 2B, the output current value of the on-vehicle generator can be estimated.

  Assuming that the power generation voltage command value to the in-vehicle generator is equal to the terminal voltage value of the in-vehicle generator, reducing the power generation voltage command value to lower the power generation voltage value of the in-vehicle generator will reduce the generated current. go. When the generated current is 0, the terminal voltage value of the in-vehicle generator matches the terminal voltage value of the in-vehicle battery, and the terminal voltage value of the in-vehicle battery at this time can be handled as an open voltage value.

Actually, when the generated voltage command value is changed, the terminal voltage value of the in-vehicle battery follows the generated voltage command value with a delay of several seconds in the region higher than the in-vehicle battery open voltage value. In a region lower than the voltage value, the terminal voltage value of the in-vehicle battery cannot follow with a delay of several seconds, and a phenomenon of drastically decreasing is observed.
Therefore, by utilizing this phenomenon, the open voltage value of the in-vehicle battery can be detected by determining the following speed of the terminal voltage value of the in-vehicle battery while gradually changing the generated voltage command value to high or low. it can.

  The on-vehicle battery state detection method according to the first aspect of the invention is such that the output voltage is controlled by a regulator to which a power generation voltage command value is given, power is generated in conjunction with the engine, and the generated power is supplied to a plurality of electric loads through a power distribution device. And an on-vehicle battery state detection method for detecting the state of the on-vehicle battery using the output voltage of the on-vehicle generator that charges the on-vehicle battery, wherein the engine speed is lower than a predetermined speed, The input terminal voltage value of the power distribution device is sequentially detected, the detected input terminal voltage value and the generated voltage command value are sequentially compared, and the input terminal voltage value and the generated voltage command value are matched. The generated voltage command value is repeatedly changed, and the open-circuit voltage value of the in-vehicle battery is obtained based on the input terminal voltage value when the input terminal voltage value and the generated voltage command value match. Based on the open-circuit voltage value obtained, and detecting a state of the vehicle battery.

  A power supply control method according to a second invention is a power supply control method for controlling a generated voltage command value or a plurality of electric loads based on an open-circuit voltage value obtained by the vehicle battery state detection method according to the first invention, The open-circuit voltage value is compared with the first voltage value and a second voltage value lower than the first voltage value. When the open-circuit voltage value is equal to or higher than the first voltage value, the generated voltage command value is set to the second voltage value. When the open voltage value is less than the first voltage value, the generated voltage command value is set higher than the first voltage value, and the open voltage value is less than the second voltage value. In some cases, an alarm display or the reduction of the electric load is executed.

  An on-vehicle battery state detection device according to a third aspect of the present invention has an output voltage controlled by a regulator to which a generated voltage command value is given, generates power in conjunction with the engine, and supplies the generated power to a plurality of electric loads through a power distribution device And an on-vehicle battery state detection device that detects the state of the on-vehicle battery using an output voltage of the on-vehicle generator that charges the on-vehicle battery, and whether or not the engine speed is lower than a predetermined engine speed. Means for sequentially detecting the input terminal voltage value of the power distribution device, the input terminal voltage value detected by the means, and the generated voltage command value during the period when the means is determined to be low. Means for successively comparing, and means for repeatedly changing the generated voltage command value so that the input terminal voltage value and the generated voltage command value match in the comparison result of the means, An open voltage value of the in-vehicle battery is obtained based on an input terminal voltage value when a child voltage value and a generated voltage command value coincide with each other, and a state of the in-vehicle battery is detected based on the obtained open voltage value. To do.

  In the vehicle battery status detection method according to the first invention and the vehicle battery status detection device according to the third invention, the output voltage is controlled by the regulator to which the power generation voltage command value is given, and the power is generated in conjunction with the engine to generate power. While supplying electric power to a plurality of electric loads through a power distribution device, the state of the vehicle battery is detected using the output voltage of the vehicle generator that charges the vehicle battery. It is determined whether or not the engine speed is lower than the predetermined engine speed. During the period when the engine speed is determined to be low, the input terminal voltage value of the power distribution device is sequentially detected, and the detected input terminal voltage value and generated voltage command value are detected. Are compared sequentially. Based on the input terminal voltage value when the input terminal voltage value and the generated voltage command value match, the generated voltage command value is repeatedly changed so that the input terminal voltage value and the generated voltage command value match in the comparison result. The open-circuit voltage value of the battery is obtained, and the state of the in-vehicle battery is detected based on the obtained open-circuit voltage value.

  A power supply control device according to a fourth aspect of the present invention includes the on-vehicle battery state detection device according to the third aspect of the invention, and generates a power generation voltage command value or a plurality of electric loads based on the open-circuit voltage value obtained by the on-vehicle battery state detection device. A power supply control device for controlling, the means for comparing the open-circuit voltage value with the first voltage value and the second voltage value lower than the first voltage value, the comparison result of the means, the open-circuit voltage value is the first When the voltage value is equal to or greater than one voltage value, the power generation voltage command value is set to be less than the second voltage value, and when the comparison result is that the open-circuit voltage value is less than the first voltage value, the generated voltage A means for setting a command value higher than the first voltage value; a means for displaying an alarm when the comparison result is less than the second voltage value; or a means for reducing the electrical load. It is characterized by providing.

  In the power supply control method according to the second invention and the power supply control device according to the fourth invention, the generated voltage command value or the plurality of electric loads are controlled based on the open-circuit voltage value obtained by the on-vehicle battery state detection device according to the third invention. To do. The obtained open-circuit voltage value is compared with the first voltage value and the second voltage value lower than the first voltage value, and when the comparison result is that the open-circuit voltage value is equal to or greater than the first voltage value, the generated voltage command value is Set to less than the second voltage value. When the open circuit voltage value is less than the first voltage value, the generated voltage command value is set higher than the first voltage value. When the open-circuit voltage value is less than the second voltage value, an alarm is displayed or the electric load is reduced.

  According to the state detection method for the in-vehicle battery according to the first aspect of the present invention, it is possible to realize the state detection method for the in-vehicle battery that can detect the state of the in-vehicle battery without using a current sensor and at a low component cost.

  According to the power supply control method according to the second aspect of the present invention, it is possible to avoid the battery run-up state based on the state of the in-vehicle battery detected by the in-vehicle battery state detection method according to the first aspect of the invention, and to prevent the in-vehicle generator from generating unnecessary power generation. Therefore, it is possible to realize a power supply control method that can improve the fuel efficiency of the vehicle.

  According to the in-vehicle battery state detection device according to the third aspect of the present invention, it is possible to realize an in-vehicle battery state detection device that can detect the state of the in-vehicle battery at a low component cost without using a current sensor.

  According to the power supply control device according to the fourth aspect of the invention, it is possible to avoid the battery running-up state based on the state of the in-vehicle battery detected by the state detection device according to the third aspect of the invention, and to prevent the in-vehicle generator from generating useless power generation. Therefore, it is possible to realize a power supply control device that can improve the fuel efficiency.

Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a vehicle-mounted battery state detection method, a power supply control method, a vehicle-mounted battery state detection device, and a power supply control device according to the present invention.
In this in-vehicle battery state detection device and power supply control device, DC power generated and rectified by the in-vehicle generator (alternator, AC generator) 1 is supplied to the in-vehicle battery 3 connected in parallel to the in-vehicle generator 1.

  The DC power generated and rectified by the in-vehicle generator 1 is supplied to each of the ignition switches (hereinafter referred to as IG switches) 10 and the switches S1 to S4 disposed in the power distribution box (distribution device) 8. Supplied to electric loads R1 to R4. The IG switch 10 is turned on / off when the IG key 5 is operated, and the operation signal is given to a power supply control unit 6 (described later). Here, it is assumed that the IG switch 10 includes an accessory switch.

A power supply control unit 6 is disposed in the power distribution box 8, and the power supply control unit 6 controls on / off of the switches S1 to S4.
The voltage detector (detecting means) 4 detects the terminal voltage value of the in-vehicle battery 3 and supplies it to the power supply control unit 6. The terminal voltage value of the in-vehicle battery 3 and the input terminal voltage value of the power distribution box (distribution device) 8 are treated as the same voltage value.
The wire harness between the in-vehicle generator 1 and the power distribution box (distribution device) 8 has a resistance Rh.

The in-vehicle generator 1 is provided with a regulator 2 that controls the output voltage based on the generated voltage command value given from the power supply control unit 6.
The power supply controller 6 is provided with the engine speed detected by the engine speed detector 9, and has a built-in memory 7. While the power generation voltage command value is gradually changed to high or low, the in-vehicle battery 3 By determining the change in the terminal voltage value, the open-circuit voltage value of the in-vehicle battery 3 is detected, and when the open-circuit voltage is too low, a warning is displayed on the display unit 11 (display means).

Hereinafter, the operations of the on-vehicle battery state detection device and the power supply control device having such a configuration will be described with reference to the flowchart of FIG.
When the IG switch 10 is turned on (S1), the power controller 6 reads the engine speed detected by the speed detector 9 (S3), and the read engine speed is idling. It is determined whether or not the rotation speed is equal to or less than a predetermined rotation speed (S5). If the read rotation speed is not less than the predetermined rotation speed, the engine rotation speed is read (S3).

If the engine speed is equal to or lower than the predetermined engine speed (S5), the power controller 6 starts an operation of gradually increasing or decreasing the power generation voltage command value to the regulator 2 (S7), and the voltage detector 4 The detected terminal voltage value of the in-vehicle battery 3 is sequentially read (S9), and the generated voltage command value and the terminal voltage value are compared (S11).
When the power supply control unit 6 gradually increases or decreases the power generation voltage command value to the regulator 2, for example, the power generation voltage command value is changed stepwise every few seconds. The voltage command value and the terminal voltage value are compared (S11), and the speed at which the terminal voltage value follows the generated voltage command value is determined. Then, it is determined whether or not it matches the terminal voltage value from when the generated voltage command value is changed, and the matching voltage value is searched (S13).

  When the generated voltage command value is reduced in a region higher than the open-circuit voltage value of the in-vehicle battery 3, the terminal voltage value follows the generated voltage command value within approximately several seconds. When the generated voltage command value is reduced in a region lower than the open circuit voltage value, the terminal voltage value does not coincide with the generated voltage command value in about 10 seconds, and the following speed becomes extremely slow.

When the power generation voltage command value does not coincide with the terminal voltage value from when the power generation voltage command value is changed (S13), the power supply control unit 6 changes the power generation voltage command value stepwise every few seconds, and each time the power generation voltage command value is changed, the in-vehicle battery 3 The generated voltage command value and the terminal voltage value are compared (S11), and the speed at which the terminal voltage value follows the generated voltage command value is determined.
When the generated voltage command value is changed and the power supply control unit 6 matches the terminal voltage value (S13), the power supply control unit 6 determines the matched voltage value as the open-circuit voltage value V0 of the in-vehicle battery 3 (S15).

Next, the power supply control unit 6 determines whether or not the determined open-circuit voltage value V0 (S15) is equal to or higher than the voltage value V1 (for example, 13V) (S17). The command value is set to be less than a voltage value V2 (for example, 12V) (S23), and the engine speed is read (S3). By setting the power generation voltage command value to be less than the voltage value V2, the fuel efficiency of the vehicle can be improved.
If the open voltage value V0 (S15) is not equal to or greater than the voltage value V1 (S17), the power supply controller 6 determines whether the open voltage value V0 is equal to or greater than the voltage value V2 (S19). If it is V2 or more, the generated voltage command value is set to a voltage value exceeding the voltage value V1 (S25), and the engine speed is read (S3).

  If the open-circuit voltage value V0 (S15) is not equal to or greater than the voltage value V2 (S19), the power supply control unit 6 warns the display unit 11 that the voltage value of the in-vehicle battery 3 is too low and the battery may run out. After the display (S21), the generated voltage command value is set to a voltage value exceeding the voltage value V1 (S25), and the engine speed is read (S3). At this time, any of the switches S1 to S4 may be turned off, and any of the electric loads R1 to R4 in use may be stopped from the least necessary level.

It is a block diagram which shows schematic structure of embodiment of the vehicle-mounted battery state detection method, power supply control method, vehicle-mounted battery state detection apparatus, and power supply control apparatus which concern on this invention. It is a characteristic view which shows the characteristic of a generator terminal voltage, a vehicle-mounted battery terminal voltage, and a generated current. It is a flowchart which shows operation | movement of the vehicle-mounted battery state detection apparatus and power supply control apparatus which concern on this invention.

Explanation of symbols

1 On-vehicle generator (alternator, alternator)
2 Regulator 3 In-vehicle battery 4 Voltage detector 5 IG key 6 Power supply control unit 8 Power distribution box (distribution device)
9 Speed detector 10 IG switch (ignition switch)
11 Display (display means)
R1-R4 Electric load Rh Harness resistance S1-S4 Switch

Claims (4)

The output voltage is controlled by the regulator to which the generated voltage command value is given, and the output of the in-vehicle generator that generates power in conjunction with the engine, supplies the generated power to multiple electric loads through the power distribution device, and charges the in-vehicle battery A state detection method for a vehicle battery that detects a state of the vehicle battery using a voltage,
In a period in which the engine speed is lower than a predetermined speed, the input terminal voltage value of the power distribution device is sequentially detected, the detected input terminal voltage value and the generated voltage command value are sequentially compared, and the input terminal The in-vehicle battery is opened based on the input terminal voltage value when the input terminal voltage value and the generated voltage command value match by repeatedly changing the generated voltage command value so that the voltage value and the generated voltage command value match. An in-vehicle battery state detection method comprising: obtaining a voltage value and detecting the state of the in-vehicle battery based on the obtained open-circuit voltage value. A power supply control method for controlling a power generation voltage command value or a plurality of electric loads based on an open-circuit voltage value obtained by an on-vehicle battery state detection method according to claim 1,
The open-circuit voltage value is compared with the first voltage value and a second voltage value lower than the first voltage value. When the open-circuit voltage value is equal to or higher than the first voltage value, the generated voltage command value is set to the second voltage value. When the open voltage value is less than the first voltage value, the generated voltage command value is set higher than the first voltage value, and the open voltage value is less than the second voltage value. When there is, a power supply control method characterized by executing alarm display or reduction of the electric load. The output voltage is controlled by the regulator to which the generated voltage command value is given, and the output of the in-vehicle generator that generates power in conjunction with the engine, supplies the generated power to multiple electric loads through the power distribution device, and charges the in-vehicle battery A vehicle-mounted battery state detection device that detects the state of the vehicle-mounted battery using a voltage,
Means for determining whether the rotational speed of the engine is lower than a predetermined rotational speed; means for sequentially detecting an input terminal voltage value of the power distribution device during a period when the means is determined to be low; Means for successively comparing the input terminal voltage value detected by the power generation unit and the generated voltage command value, and repeatedly changing the generated voltage command value so that the input terminal voltage value and the generated voltage command value coincide with each other as a result of the comparison. Means for obtaining an open-circuit voltage value of the in-vehicle battery based on the input terminal voltage value when the input terminal voltage value and the generated voltage command value coincide with each other, and based on the obtained open-circuit voltage value, An on-vehicle battery state detection device characterized by detecting a state. A power supply control device comprising the vehicle-mounted battery state detection device according to claim 3 and controlling a generated voltage command value or a plurality of electric loads based on an open-circuit voltage value obtained by the vehicle-mounted battery state detection device. ,
The means for comparing the open-circuit voltage value with the first voltage value and the second voltage value lower than the first voltage value, and the comparison result of the means is that the open-circuit voltage value is equal to or greater than the first voltage value, When the generated voltage command value is less than the second voltage value, and the comparison result indicates that the open voltage value is less than the first voltage value, the generated voltage command value is set to be less than the first voltage value. A power supply comprising: a means for setting a high value; and a means for displaying an alarm when the comparison result indicates that the open-circuit voltage value is less than the second voltage value, or a means for reducing the electric load. Control device.

Images