JP2008279901A - Power feeding system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit operation position information to an electronic control unit when abnormality is generated on a communication line for transmitting the operation position information to the electronic control unit for controlling feeding of power to respective loads according to an operation position of an ignition switch. <P>SOLUTION: The power feeding system for the vehicle is provided with a power distributor providing a voltage adjustment circuit for voltage-boosting on a power circuit connected to a battery; a first ECU connected to the voltage adjustment circuit of the power distributor and detecting the operation position of the ignition switch; and a second ECU fed with the power from the power distributor, receiving the operation position information of the ignition switch from the first ECU through the communication line and feeding the power to the load connected according to the operation position information. In generation of abnormality of communication between the first ECU and the second ECU, the first ECU transmits a voltage control signal to the power distributor and a power voltage is boosted by the voltage adjustment circuit. The second ECU obtains the operation position information of the ignition by the boosted voltage fed from the power distributor and feeds the power to the load according to the operation position information. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle power supply system, and more particularly, to a power supply system that supplies power to a load in accordance with an operation position (off position, accessory position, on position) of an ignition switch.

Usually, in a vehicle power supply system, an occupant operates an ignition key and a push button (hereinafter collectively referred to as an ignition switch), and an electronic control unit (ECU) is operated according to an off position, an accessory (ACC) position, and an on position. The power supply is distributed to the required load including the switch.
In this type of vehicle power supply system, in order to reduce the number of power lines that supply power to the load via the power lines at the ignition switch operation positions (off position, accessory position, on position), the operation of the ignition switch There is provided a system for providing a dedicated electronic control unit for controlling the power distribution to each load according to the position, and controlling the load for distributing the power according to the operation position of the ignition switch by the electronic control unit.

For example, a vehicle power supply system disclosed in Japanese Patent Laid-Open No. 2002-144985 (Patent Document 1) includes a fusible link box 2 connected to a battery 1 and a junction box 3 connected to a load, as shown in FIG. Each of the CPUs is housed, and the CPUs are connected to each other by a power line 4 and a control signal multiplex line 5.
In normal times, control signals are transmitted / received via the control signal multiplex line 5 to supply power to the load according to the operation position of the ignition switch, and the state of the control signal multiplex line 5 is monitored by the CPU of the fusible link box 2; When an abnormality of the control signal multiplex line 5 is detected, a control signal is superimposed on the power line 4 and a control signal is extracted from the power source superimposed on the junction box 3 side. Based on the extracted control signal Distributes power to the connected load.

  However, in the vehicle power supply system 1 provided in Patent Document 1, since a control signal having an amplitude is superimposed on the power supply line 4, it becomes a noise source for the power supply voltage and adversely affects the equipment to which the power is supplied. May cause effects.

JP 2002-144985 A

  The present invention has been made in view of the above problems, and when an abnormality occurs in a communication line that transmits a control signal of operation position information of an ignition switch, a control signal that becomes a noise source is not superimposed on the power line. An object of the present invention is to enable transmission of operation position information of an ignition switch to an electronic control unit that controls power supply to a load.

In order to solve the above-mentioned problems, the present invention provides a power supply distributor in which a voltage adjustment circuit for boosting is provided in a power supply circuit connected to a battery,
A first electronic control unit connected to the voltage adjusting circuit of the power distributor and detecting an operation position (off position, accessory position, on position) of the ignition switch;
Power is supplied from the power distributor, and the operation position information of the ignition switch is received from the first electronic control unit via a communication line, and the power is supplied to the connected load according to the operation position information. A second electronic control unit;
With
When a communication abnormality occurs between the first electronic control unit and the second electronic control unit, the first electronic control unit transmits a voltage control signal to the power supply distributor, and boosts the power supply voltage by the voltage adjustment circuit, The second electronic control unit obtains ignition operation position information with a boosted voltage supplied from a power distributor, and supplies power to the load according to the operation position information. A power supply system is provided.

In the vehicular power supply system configured as described above, when a communication abnormality occurs between the first electronic control unit and the second electronic control unit, the power supply voltage is ignited by the voltage adjustment circuit for boosting the power distributor. The pressure is increased according to the operation position of the switch. The second electronic control unit that controls power supply to the load acquires operation position information of the ignition from the boosted voltage, and supplies power to the load according to the operation position information.
Therefore, even if a communication abnormality occurs between the first electronic control unit and the second electronic control unit, power can be supplied to a required load according to the operation position of the ignition switch. In addition, since the control signal for generating the amplitude as in the conventional example is not superimposed on the power supply line, no noise is generated in the voltage, and a stable and constant voltage supplied to the device connected to the power supply distributor is provided. Can be supplied.

The power supply divider is provided with the voltage adjustment circuit for boosting in parallel via a relay in the power supply circuit connecting the battery and the second electronic control unit, and from the first electronic control unit to the power supply divider. Switching the relay with a relay control signal to be transmitted and connecting a voltage adjustment circuit for boosting to the second electronic control unit;
In addition, it is preferable that the voltage to be boosted is made different according to the accessory position and the on position of the ignition switch by the voltage control signal from the first electronic control unit.

  For example, the 12-volt power supply is boosted to 16 volts when the ignition switch is in the accessory position, and to 18 volts when the ignition switch is in the on position, so that the second electronic control unit can detect the operation position of the ignition switch based on the boosted voltage. Yes.

When the second electronic control unit detects that the operation position of the ignition switch is the accessory position based on the detected voltage, the second electronic control unit supplies power to a load such as a cigarette lighter.
Similarly, when it is detected that the operation position of the ignition switch is the on position, power is supplied to a load such as a wiper or an air conditioner.

  The second electronic control unit includes a step-down voltage adjustment circuit that steps down the stepped-up voltage to make a constant voltage, and an A / D conversion circuit in parallel, and a digital signal converted by the A / D conversion circuit It is preferable that the operation position information of the ignition switch is acquired by the above and the power source stepped down by the step-down voltage adjustment circuit according to the operation position information is supplied to the load.

  According to the above configuration, the power supply voltage is boosted to transmit the operation position of the ignition switch to the second electronic control unit. However, in the voltage adjustment circuit for stepping down the second electronic control unit, the boosted power supply voltage is Since the voltage is returned to the predetermined voltage before boosting, the supply voltage to the load can be kept constant.

The first electronic control unit includes an abnormality detection unit provided with an interruption period threshold value of a signal periodically transmitted from the second electronic control unit, and the voltage control is performed when a communication abnormality is detected by the abnormality detection unit. Preferably, a signal is transmitted to the power distributor.
In this way, the reception interval of signals (for example, signals related to sensor information and the activation state of the electronic control unit) transmitted from the second electronic control unit to the first electronic control unit via the communication line at a constant cycle is counted. In addition, since the first electronic control unit is provided with an abnormality detection unit that detects an abnormality when reception is interrupted for a certain period of time, communication abnormality between the first electronic control unit and the second electronic control unit is ensured. Can be detected. In addition, since the transmission of the signal via the communication line is faster than the case where the signal is superimposed on the power line, for example, if the interruption period threshold is 10 seconds, the abnormality is quickly detected 10 seconds after the occurrence of the communication abnormality. Then, the means for transmitting the operation position information of the ignition switch can be switched to the means for transmitting the operation position information of the ignition switch by changing the power supply voltage from the means for transmitting the operation position information of the ignition switch using the communication line.

As described above, according to the present invention, when the operation position information of the ignition switch cannot be transmitted to the second electronic control unit that controls the power supply to the load via the communication line, the voltage adjustment of the power distributor is performed. The circuit boosts the power supply voltage according to the operation position of the ignition switch, obtains the operation position information of the ignition from the boosted voltage by the second electronic control unit, and supplies power to the load according to the operation position information. Can be supplied.
Therefore, even if a communication abnormality occurs between the first electronic control unit and the second electronic control unit that detect the operation position of the ignition switch, power is supplied to a required load according to the operation position of the ignition switch. In addition, since the signal related to the operation position information of the ignition switch is not superimposed on the power supply line, no noise is generated in the power supply, and a stable power supply can be supplied to the load.

Embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment of the present invention.
The vehicle power supply system 10 according to the present embodiment is connected to a power distributor 12 that distributes power supplied from a battery 11 to a plurality of loads, and an ignition switch 13, and detects the operation position of the ignition switch. A control unit 14 (hereinafter referred to as a first ECU) and a second electronic control unit 15 (hereinafter referred to as a first ECU) that supplies power from the power distributor 12 and supplies power to the load 16 according to the operation position of the ignition switch. (Referred to as a second ECU).

As shown in FIG. 1, the power distributor 12 is connected to the battery 11 via the power line 21 and is also connected to the second ECU 15 via the power line 22 to boost the power circuit of the power distributor 12. Voltage adjustment circuit 12a is provided.
The voltage adjustment circuit 12 is a battery of 12 volts depending on the operation position (off position, accessory position, on position) of the ignition switch 13 when an abnormality occurs in communication between the first ECU 14 and the second ECU 15 described later. This circuit boosts the power supply.
In the present embodiment, the power supply voltage is not boosted when the ignition switch 13 is in the off position, the power supply voltage is boosted to 16 volts when the ignition switch 13 is in the accessory position, and the power supply voltage is boosted to 18 volts when the ignition switch 13 is in the on position. .

The first ECU 14 connected to the ignition switch 13 is connected to the second ECU 15 and the voltage adjustment circuit 12a for boosting the power distributor 12 via communication lines 23 and 24, respectively.
The first ECU 14 includes an operation position detection unit 14 a that detects the operation position of the ignition switch 13 and an abnormality detection unit 14 b that detects an abnormality in the communication line 23.
The operation position detector 14a detects the operation position (off position, accessory position, on position) of the ignition switch 13, and transmits the detected operation position information of the ignition switch to the second ECU 15 via the communication line 23. The power supply to the load is controlled according to the operation position information.

Further, the abnormality detection unit 14b is provided with an interruption period threshold value of a signal periodically transmitted from the second ECU 15 via the communication line 23, and the signal periodically transmitted from the second ECU 15 is longer than the interruption period threshold value. If the transmission line 23 is not transmitted, the abnormality is detected as an abnormality has occurred in the communication line 23. When an abnormality is detected by the abnormality detection unit 14b, a voltage control signal is transmitted to the voltage adjustment circuit 12a for boosting the power distributor 12 via the communication line 24, and the voltage adjustment for boosting received the voltage control signal. In the circuit 12a, the power supply voltage is boosted as described above in accordance with the operation position of the ignition switch.
In the present embodiment, the interruption period threshold value in the abnormality detection unit 14b is set to 10 seconds, and an abnormality occurs when the interruption of the signal from the second ECU 15 exceeds 10 seconds.

A load 16 to be controlled is connected to the second ECU 15.
The second ECU 15 includes an intelligent power switch 15a (hereinafter referred to as IPS), and controls the power supply to the load 16 by turning on / off the IPS 15a according to the operation position information of the ignition switch. In the present embodiment, power is supplied from the second ECU 15 to the load 16 only when the load 16 is composed of a wiper, an air conditioner, or the like, and the operation position information of the ignition switch is in the on position.
The second ECU 15 also includes a step-down voltage adjustment circuit (DC / DC converter) 15b that steps down the voltage stepped up by the step-up voltage adjustment circuit 12a of the power distributor 12 to obtain a constant voltage of 12 volts. An A / D conversion circuit 15c that converts the boosted voltage into a digital signal is provided in parallel.

When the boosted power is supplied to the second ECU 15, the voltage is reduced to 12 volts by the step-down voltage adjustment circuit 15b, and the voltage boosted by the A / D conversion circuit 15c is converted into a digital signal. Thus, the operation position information of the ignition switch is acquired, and the IPS 15a is turned on / off according to the operation position information. When the IPS 15a is turned on by the operation position information, the 12-volt power source stepped down by the voltage adjustment circuit 15b for step-down is supplied to the load 16, and when the IPS 15a is turned off by the operation position information, the load 16 is not supplied with power. .
The vehicle power supply system 10 of the present embodiment includes a plurality of second ECUs 15 and a load 16. Each of the second ECUs 15 is connected to the power distributor 12 via the power line 22 and the first ECU 14 via the communication line 23. Although they are connected, illustration is omitted.

Next, operation | movement of the vehicle power supply system 10 of this embodiment is demonstrated with reference to the flowchart of FIG.
First, if no abnormality is detected by the abnormality detection unit 14b of the first ECU 14, the operation position information of the ignition switch detected by the operation position detection unit 14a is transmitted from the first ECU 14 to the second ECU 15 via the communication line 23 ( Step S1).
In the second ECU 15 that has received the operation position information of the ignition switch, the IPS 15a is turned on / off according to the operation position information, and when the IPS 15a is turned on by the operation position information, power is supplied to the load 16 (step) S2).
As described above, when there is no abnormality in the communication line 23, the operation position information of the ignition switch is transmitted from the first ECU 14 to the second ECU 15 via the communication line 23 between the first ECU 14 and the second ECU 15, and the power distributor 12 The voltage adjustment circuit 12a for boosting does not boost the power supply.

On the other hand, when an abnormality is detected by the abnormality detection unit 14b of the first ECU 14, a voltage control signal instructing the voltage adjustment circuit 12a of the power distributor 12 to boost the power is sent from the first ECU 14 to the power distributor 12. It is transmitted (step S3).
When the power supply distributor 12 receives the voltage control signal, the voltage adjustment circuit 12a for boosting boosts the power supply voltage according to the operation position of the ignition switch (step S4). That is, the power supply voltage is not boosted when the ignition switch 13 is in the off position, the power supply voltage is boosted to 16 volts when in the accessory position, and the power supply voltage is boosted to 18 volts when in the on position.
In the second ECU 15 supplied with the boosted power as described above, the boosted voltage is stepped down to 12 volts by the step-down voltage adjustment circuit 15b, and the boosted voltage is converted into a voltage by the A / D conversion circuit 15c. It converts into the digital signal according to a value, and acquires the operation position information of an ignition switch (step S5).
When the IPS 15a is turned on / off according to the acquired operation position information and the IPS 15a is turned on according to the operation position information, the power reduced by the voltage adjustment circuit 15b for step-down is supplied to the load 16 (step S6). .
As described above, when an abnormality occurs in the communication line 23, the power supply voltage is boosted according to the operation position of the ignition switch, and the second ECU 15 acquires the operation position information of the ignition switch from the boosted power supply voltage value. I can do it.

According to the above configuration, when the operation position information of the ignition switch cannot be transmitted to the second ECU 15 that controls the power supply to the load 16 via the communication line 23, the voltage adjustment circuit 12a for boosting the power distributor 12 is provided. Thus, the power supply voltage is boosted in accordance with the operation position of the ignition switch, and the operation position information of the ignition is obtained from the boosted voltage in the second ECU, and the power is supplied to the load 16 in accordance with the operation position information. be able to.
Therefore, even if a communication abnormality occurs between the first ECU 14 and the second ECU 15, power can be supplied to the required load 16 according to the operation position of the ignition switch. In addition, since the control signal related to the operation position information of the ignition switch is not superimposed on the power supply line 22, no noise is generated in the power supply, and a stable power supply can be supplied to the load 16.

3 and 4 show a second embodiment of the present invention.
In the vehicle power supply system 10 of the present embodiment, the configuration of the power distributor 12 is different from that of the first embodiment.
In the power distributor 12 of the present embodiment, a voltage adjusting circuit for boosting is not provided in series in the power circuit connecting the battery 11 and the second ECU 15, but the voltage adjusting circuit for boosting is connected to the power circuit via the relay 12b. 12a are provided in parallel. Therefore, by switching the relay 12b, when the power supply voltage does not need to be boosted, the power is supplied to the load 16 without going through the voltage adjustment circuit 12a, while the voltage adjustment is performed only when the power supply voltage needs to be boosted. The circuit 12a boosts the power supply.

  The voltage adjustment circuit 12a for boosting and the relay 12b are connected to the first ECU 14 via communication lines 25 and 26, respectively, and a relay control signal is transmitted from the first ECU 14 to the relay 12b via the communication line 26. A voltage control signal is transmitted from the first ECU 14 to the voltage adjustment circuit 12a for boosting via the communication line 25.

  While the communication between the first ECU 14 and the second ECU 15 is normally performed and the operation position information of the ignition switch is transmitted from the first ECU 14 to the second ECU 15, the voltage adjustment circuit 12a for boosting is connected to the power circuit as shown in FIG. Not connected to. Therefore, the power supplied from the battery 11 is supplied to the second ECU 15 without being boosted by the voltage adjustment circuit 12a for boosting. In the second ECU 15, the power is loaded according to the operation position information of the ignition switch received from the first ECU 14. 16 is supplied.

  On the other hand, when an abnormality of the communication line 23 is detected by the abnormality detection unit 14b of the first ECU 14, a relay control signal is transmitted from the first ECU 14 to the relay 12b via the communication line 26. As shown in FIG. By switching, a voltage adjustment circuit 12a for boosting is interposed in the power supply circuit. Therefore, the power supplied from the battery 11 is boosted to a required voltage in accordance with the voltage control signal transmitted from the first ECU 14 in the voltage adjustment circuit 12a for boosting, and the boosted power is supplied to the second ECU 15. . The power supplied to the second ECU 15 is stepped down to a predetermined voltage by the step-down voltage adjustment circuit 15b and digitally converted by the A / D conversion circuit 15c, as in the first embodiment, and the operation position information of the ignition switch. Is acquired, and power is supplied to the load 16 in accordance with the operation position information.

According to the above configuration, when the operation position information of the ignition switch cannot be transmitted to the second ECU 15 that controls the power supply to the load 16 via the communication line 23, the relay 12b of the power distributor 12 is switched to increase the voltage. The voltage adjustment circuit 12a can boost the power supply voltage according to the operation position of the ignition switch. Then, the operation position information of the ignition can be acquired from the boosted voltage in the second ECU, and power can be supplied to the load 16 according to the operation position information.
Therefore, even if a communication abnormality occurs between the first ECU 14 and the second ECU 15, power can be supplied to the required load 16 according to the operation position of the ignition switch, and control related to operation position information of the ignition switch Since no signal is superimposed on the power supply line 22, no noise is generated in the power supply, and a stable power supply can be supplied to the load 16.
In addition, since another structure and an effect are the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

It is a block diagram of the power supply system for vehicles of a 1st embodiment of the present invention. It is a flowchart which shows operation | movement of the power supply system for vehicles. It is a block diagram of the vehicle power supply system at the normal time of the second embodiment. It is a block diagram of the power supply system for vehicles at the time of abnormality occurrence. It is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle power supply system 11 Battery 12 Power distributor 12a Voltage adjustment circuit 12b for boosting 12b Relay 13 Ignition switch 14 1st electronic control unit (1ECU)
14a Operation position detection unit 14b Abnormality detection unit 15 Second electronic control unit (second ECU)
15b Voltage adjustment circuit for step-down 15c A / D conversion circuit 16 Load 23 Communication line

Claims (4)

A power distributor provided with a voltage adjusting circuit for boosting in a power circuit connected to the battery;
A first electronic control unit connected to the voltage adjusting circuit of the power distributor and detecting an operation position (off position, accessory position, on position) of the ignition switch;
Power is supplied from the power distributor, and the operation position information of the ignition switch is received from the first electronic control unit via a communication line, and the power is supplied to the connected load according to the operation position information. A second electronic control unit;
With
When a communication abnormality occurs between the first electronic control unit and the second electronic control unit, the first electronic control unit transmits a voltage control signal to the power supply divider, and boosts the power supply voltage by the voltage adjustment circuit, The second electronic control unit obtains ignition operation position information with a boosted voltage supplied from a power distributor, and supplies power to the load according to the operation position information. Power supply system. The power supply divider is provided with the voltage adjustment circuit for boosting in parallel via a relay in the power supply circuit connecting the battery and the second electronic control unit, and from the first electronic control unit to the power supply divider. Switching the relay with a relay control signal to be transmitted and connecting a voltage adjustment circuit for boosting to the second electronic control unit;
The vehicle power supply system according to claim 1, wherein the voltage to be boosted is varied according to the accessory position and the on position of the ignition switch by a voltage control signal from the first electronic control unit.   The second electronic control unit includes a step-down voltage adjustment circuit that steps down the stepped-up voltage to make a constant voltage, and an A / D conversion circuit in parallel, and a digital signal converted by the A / D conversion circuit 3. The vehicle power supply system according to claim 1, wherein operation position information of the ignition switch is acquired by the step S <b> 1, and power that is stepped down by the step-down voltage adjustment circuit is supplied to the load according to the operation position information.   The first electronic control unit includes an abnormality detection unit provided with an interruption period threshold value of a signal periodically transmitted from the second electronic control unit, and the voltage control is performed when a communication abnormality is detected by the abnormality detection unit. The vehicle power supply system according to any one of claims 1 to 3, wherein a signal is transmitted to the power distributor.

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