JP2007112364A - Car-mounted power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the dark current after ignition-off without bringing about a functional drop in monitoring the condition of an in-vehicle switch. <P>SOLUTION: A car-mounted power supply system is structured so that power is supplied from a car-mounted battery by turning on a transistor and the conditional monitoring of the in-vehicle switch by a microcomputer of a load ECU is made possible, whereby the conditional monitoring is executed normally at all times. Discrimination is made whether any person exists in the cabin (Step 200), and also the On-Off state of an ignition switch is discriminated. In a case no person exists in the cabin during execution of the conditional monitoring of the in-vehicle switch in the ignition-off state, power supplying from the battery is prohibited by turning off the transistor so as to interrupt the conditional monitoring of the in-vehicle switch (Step 106). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-vehicle power supply system, and more particularly to an in-vehicle power supply system mounted on a vehicle including a state monitoring unit that can monitor the state of a vehicle interior switch when power is supplied from an in-vehicle battery.

2. Description of the Related Art Conventionally, an in-vehicle power supply system that supplies power from a battery to a load to be operated when the ignition is off is known (see, for example, Patent Document 1). In this system, it is determined whether the ignition switch is on or off, and the elapsed time from when the ignition switch is switched from on to off is calculated. Then, when the elapsed time reaches a predetermined set time (for example, 8 days), power supply from the battery to the electric load is cut off. Therefore, according to the above system, it is possible to reduce the dark current in the ignition-off state, thereby preventing the battery from running out.
JP 10-225033 A

  However, if the power supply from the battery to the electric load is not cut off until a certain time has elapsed after the ignition switch is turned off as in the above-described conventional system, the power supply to the electric load is actually supplied after the ignition switch is turned off. The power supply may be executed even when the power supply is unnecessary. In this respect, there remains room for further reduction in dark current.

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide an in-vehicle power supply system capable of reducing dark current as much as possible in an ignition-off state.

  The above-described object is a power supply system mounted on a vehicle including a state monitoring unit capable of monitoring the state of a vehicle interior switch by supplying power from a vehicle-mounted battery, and whether or not a person exists in the vehicle interior. A person presence determining means for determining whether or not there is no passenger in the vehicle interior by the person presence determining means, and prohibiting the power supply from the in-vehicle battery to prevent This is achieved by an in-vehicle power supply system including state monitoring stopping means for stopping state monitoring.

  In the invention of this aspect, the state monitoring means can monitor the state of the switch in the vehicle interior by supplying power from the in-vehicle battery. In addition, when there are no more passengers in the vehicle interior, the power monitoring from the in-vehicle battery is prohibited, and the state monitoring of the vehicle interior switch by the state monitoring means is stopped. If no passengers are present in the vehicle compartment, it is not necessary to monitor the state of the vehicle interior switch, and it is not necessary to supply power from the in-vehicle battery for monitoring the state. Therefore, according to the present invention, power supply from the in-vehicle battery is prohibited when no passenger is present in the vehicle interior, so that dark current is reduced in the ignition off state without degrading the function of monitoring the state of the vehicle interior switch. Can be achieved as much as possible.

  In this case, in the above-described in-vehicle power supply system, the state monitoring stop unit prohibits power supply from the in-vehicle battery when it is determined by the human presence determination unit that no occupant is present in the ignition off state. Thus, the state monitoring of the vehicle interior switch by the state monitoring means may be stopped.

  In addition, in the above-described in-vehicle power supply system, when a state of a predetermined sensor or switch changes, if provided with a release unit that cancels the stop of the state monitoring of the vehicle interior switch by the state monitoring stop unit, Even when the monitoring of the vehicle interior switch is stopped due to the prohibition of power supply from the in-vehicle battery, if the state of the predetermined sensor or switch subsequently changes, the power supply from the in-vehicle battery will again supply the vehicle interior switch. It becomes possible to perform state monitoring.

  According to the present invention, it is possible to reduce the dark current in the ignition-off state without causing a deterioration in the function of monitoring the state of the vehicle interior switch.

  FIG. 1 shows a configuration diagram of an in-vehicle power supply system mounted on a vehicle according to an embodiment of the present invention. The in-vehicle power supply system of the present embodiment includes an in-vehicle battery 10 as shown in FIG. The in-vehicle battery 10 is a power source that outputs a predetermined output voltage (for example, DC 12 volts).

  An electronic control unit (hereinafter referred to as a load ECU) 12 is connected to the in-vehicle battery 10 as an electric load. The load ECU 12 includes a power supply IC 14 and a microcomputer (hereinafter referred to as a microcomputer) 16. The power supply IC 14 is a switching power supply circuit configured by a DC-DC converter using a switching transistor, and rectifies and smoothes an induced voltage obtained by switching the output voltage from the battery 10 to a predetermined voltage (for example, DC 5 volts). ) Is output. The output voltage of the power supply IC 14 is supplied to the microcomputer 16. The microcomputer 16 can operate when power is supplied from the power supply IC 14.

  Connected to the microcomputer 16 are a plurality (n) of vehicle interior switches 20 that are provided in the vehicle interior and can be operated by an occupant (especially a driver) riding in the vehicle. The vehicle interior switch 20 includes, for example, a headlamp switch for switching the headlamp and taillight on / off, a hazard switch for switching the hazard lamp on / off, a seat switch for changing the seat position, and a steering column switch. It is a tilt telescopic switch for operating a tilt mechanism and a telescopic mechanism, etc., and is a switch that can normally operate its controlled object even when an ignition switch described later is in an off state that is neither IG on nor ACC on .

  The microcomputer 16 has a ROM for storing data and a control program and a RAM for temporarily storing the data, and has a function of monitoring the state of the vehicle interior switch 20. The microcomputer 16 is connected to the input side of the power supply IC 14 and is connected to a transistor 24 connected via a resistor 22 between the microcomputer 16 and the vehicle interior switch 20. The transistor 24 is turned on / off according to a command from the microcomputer 16. The microcomputer 16 supplies a command signal to the transistor 24 so that the transistor 24 is turned on when the state of the vehicle interior switch 20 should be monitored.

  The microcomputer 16 is also connected with an ignition switch 26 operated by a vehicle driver. The ignition switch 26 has a starter contact for starting the engine, an IG contact for continuing operation of the started engine and enabling various electrical components, and stopping the operation of the engine and predetermined electrical components. And an ACC contact for enabling operation. The microcomputer 16 has a function of determining on / off of the IG contact and the ACC contact of the ignition switch 26.

  Moreover, the vehicle-mounted power supply system of a present Example is provided with master ECU30 which operate | moves by always supplying power. An occupant detection device 32 mounted on the vehicle is connected to the master ECU 30 in order to detect whether an occupant is present in the passenger compartment. The occupant detection device 32 is, for example, an infrared sensor that outputs a signal corresponding to the temperature distribution in the vehicle interior, a seating sensor that outputs a signal corresponding to the seat load, a camera that captures an image of the vehicle interior, and a signal corresponding to an odor in the vehicle interior. Odor sensor, tire pressure sensor that outputs signals according to vehicle tire pressure, inclination sensor that outputs signals according to vehicle body tilt, vehicle height sensor that outputs signals according to vehicle body height, getting off It is a getting-off switch that is sometimes operated by a passenger to notify that it gets off. An output signal from the occupant detection device 32 is supplied to the master ECU 30. The master ECU 30 determines whether there is an occupant in the passenger compartment, threshold values and switch states relating to the passenger compartment temperature distribution, seat load, image recognition, odor, tire pressure, tire inclination angle, or vehicle height. Based on the output from the infrared sensor, seating sensor, camera, odor sensor, tire pressure sensor, tilt sensor, vehicle height sensor, or alighting switch as the occupant detection device 32. It is determined whether or not there is a passenger.

  It should be noted that the determination of whether or not there is an occupant in the vehicle interior may be performed by combining the outputs of a plurality of sensors and switches as described above, and according to such a configuration, the determination accuracy of passenger detection in the vehicle interior is improved. To do. Further, this determination may determine that no occupant is present in the vehicle interior when a predetermined time elapses without the state of the output of the vehicle interior switch 20 or the sensor provided in the vehicle interior changing. In addition, it is further determined that there is no occupant in the passenger compartment when the ignition switch 26 is turned off (IG contact and ACC contact are both turned off) and the vehicle door closing state does not change and a predetermined time elapses. Also good.

  The master ECU 30 is further connected to a vehicle state detection device 34 mounted on the vehicle in order to detect whether or not a person is about to get on by switching the vehicle from the outside of the vehicle. The vehicle state detection device 34 outputs, for example, an infrared sensor or receiver that outputs a signal according to whether or not a person has approached the vehicle from the outside, or a signal that depends on whether or not the vehicle is unlocked from the outside. A door unlock device, a courtesy switch that outputs a signal according to the open / closed state of the vehicle door. An output signal of the vehicle state detection device 34 is supplied to the master ECU 30. Based on the output of sensors and switches as the vehicle state detection device 34, the master ECU 30 moves from the outside of the vehicle to the vehicle, the vehicle door is shifted from the locked state to the unlocked state, and the vehicle door is changed from the closed state to the open state. It is determined whether or not there is a change in the vehicle state such as whether or not the vehicle has been shifted, and it is determined whether or not a person is going to get on the vehicle from outside.

  The master ECU 30 is connected to the microcomputer 16 of the load ECU 12 described above via the in-vehicle LAN 36. The master ECU 30 determines whether or not a passenger is present in the vehicle interior based on the output of the occupant detection device 32 and whether or not a person based on the output of the vehicle state detection device 34 is about to get on the vehicle from the outside. These determination results are supplied to the microcomputer 16 through the in-vehicle LAN 36, and the microcomputer 16 grasps the determination results based on information supplied from the master ECU 30.

  Next, with reference to FIG.2 and FIG.3, operation | movement of the vehicle-mounted power supply system of a present Example is demonstrated. FIG. 2 shows a time chart for explaining the operation of the in-vehicle power supply system of this embodiment. FIG. 3 shows a flowchart of an example of a control routine executed in the in-vehicle power supply system of this embodiment.

  In the system of the present embodiment, the microcomputer 16 of the load ECU 12 supplies a command signal to the transistor 24 so as to be in an ON state in order to constantly monitor the state of the vehicle interior switch 20 except when described later ( Step 100). When such supply is performed, the transistor 24 is turned on, and current flows from the in-vehicle battery 10 through the resistor 22 to the contact with the microcomputer 16 of the vehicle interior switch 20.

  The microcomputer 16 monitors the state of the vehicle interior switch 20 based on the voltage generated at the contact point with the vehicle interior switch 20 when the transistor 24 is turned on and current is supplied from the in-vehicle battery 10 as described above. Specifically, when the above voltage is at a high voltage, it is determined that the vehicle interior switch 20 is in an off state, and when the above voltage is at a low voltage (ground voltage), the vehicle interior switch 20 is turned on. It is determined that it is in a state. When the state change of the vehicle interior switch 20 occurs, a command for changing the operation of a control target (for example, a headlamp) corresponding to the vehicle interior switch 20 that has caused the state change is issued. In this case, even in a situation where the ignition switch 26 is in the off state, the controlled object changes its operation in accordance with the state change of the vehicle interior switch 20.

  In the system of this embodiment, when the ignition switch 26 is turned off from the on state, the IG contact and the ACC contact are turned off, so that the operation of the vehicle engine is stopped and the operation of various electrical components is stopped. Is done. The microcomputer 16 determines the on / off state of the ignition switch 26 (step 102).

  Further, in the system of the present embodiment, the master ECU 30 determines whether or not there is an occupant in the passenger compartment based on the output from the occupant detection device 32 at all times or at predetermined time intervals (step 200). If there is an occupant in the vehicle interior, the vehicle interior switch 20 may be operated to change the state, so the microcomputer 16 must monitor the state of the vehicle interior switch 20. Therefore, when such a determination is made (when an affirmative determination is made in step 200), information indicating that no occupant is present in the vehicle compartment is not transmitted to the microcomputer 16, and the microcomputer 16 does not normally transmit the vehicle-mounted battery 10 Therefore, the power supply from the vehicle interior switch 20 to the vehicle interior switch 20 side is performed to monitor the state of the vehicle interior switch 20.

  On the other hand, when no occupant is present in the vehicle interior, the vehicle interior switch 20 is not operated and the state thereof does not change, so it is not necessary to monitor the state of the vehicle interior switch 20. Therefore, when such a determination is made (time t2 shown in FIG. 2; negative determination at step 200), information indicating that no occupant is present in the passenger compartment is transmitted to the microcomputer 16 via the in-vehicle LAN 36 (step 202). .

  In the situation where the microcomputer 16 is monitoring the state of the vehicle interior switch 20 by supplying power from the in-vehicle battery 10 in the ignition off state (after time t1 shown in FIG. 2; at the time of affirmative determination in step 102). When the information indicating that no passenger is present in the vehicle interior transmitted from the master ECU 30 is received (step 104), it is determined that there is no possibility that the vehicle interior switch 20 will be operated thereafter, and the state of the vehicle interior switch 20 is determined. In order to stop the monitoring, the on command to the transistor 24 is stopped to prohibit the power supply from the in-vehicle battery 10 to the contact of the microcomputer 16 of the in-vehicle switch 20 and the sleep function in which the state monitoring function of the microcomputer 16 is not exhibited. The mode is entered (step 106). In this case, thereafter, the state monitoring of the vehicle interior switch 20 by the microcomputer 16 is stopped.

  Thus, according to the vehicle-mounted power supply system of the present embodiment, the state of the vehicle interior switch 20 can be monitored by supplying power from the vehicle-mounted battery 10 even in the ignition-off state, while such an ignition-off state is provided. If the passenger is no longer in the passenger compartment while the vehicle interior switch 20 is being monitored, the state monitoring of the vehicle interior switch 20 should be stopped by prohibiting the power supply from the in-vehicle battery 10 thereafter. Can do. If no passenger is present in the vehicle interior, the vehicle interior switch 20 is not operated, and it is not necessary to monitor the state of the vehicle interior switch 20. There is no need to supply power.

  Therefore, according to the system of the present embodiment, when the ignition is off and no occupant is present in the vehicle compartment, the current consumed by the microcomputer 16 from the in-vehicle battery 10 to the microcomputer 16 via the power supply IC 14 (see FIG. 1, the current required for realizing the state monitoring function of the vehicle interior switch 20 does not flow, and the vehicle interior switch that goes from the in-vehicle battery 10 to the vehicle interior switch 20 side through the transistor 24 and the resistor 22. Since the current consumed to monitor the state 20 (Id2 in FIG. 1) does not flow, the dark current in the ignition-off state is not reduced without causing a deterioration in the function of monitoring the state of the vehicle interior switch 20 when the ignition is off. Can be reduced. For this reason, according to the present Example, it is possible to suppress the battery running out of the vehicle-mounted battery 10 when the ignition is off.

  In this embodiment, the master ECU 30 transmits information indicating that no occupant is present in the vehicle interior to the microcomputer 16 of the load ECU 12 as described above, and then determines the vehicle state based on the output from the vehicle state detection device 34. It is determined whether or not there is a change (step 204). As a result, when it is determined that there is a change in the vehicle state (time t3 shown in FIG. 2; at the time of an affirmative determination in step 204), it can be determined that a person is about to get into the vehicle from the outside of the vehicle. In order to wake up the microcomputer 16 by an external interrupt, the wakeup command is transmitted to the microcomputer 16 through the in-vehicle LAN 36 (step 206).

  When the microcomputer 16 receives the wake-up command transmitted from the master ECU 30 in the situation where the state monitoring of the vehicle interior switch 20 is stopped as described above (step 108), the microcomputer 16 sets the sleep mode of the microcomputer 16 by an external interrupt. After that, it is determined that the vehicle interior switch 20 may be operated, and an on command is supplied to the transistor 24 from the in-vehicle battery 10 in order to cancel the suspension of the state monitoring of the vehicle interior switch 20. The power supply to the vehicle interior switch 20 side is resumed (step 110). In this case, the state monitoring of the vehicle interior switch 20 by the microcomputer 16 is resumed thereafter.

  As described above, according to the in-vehicle power supply system of the present embodiment, the ignition is off and the occupant is not present in the vehicle interior, so that the power supply from the in-vehicle battery 10 is prohibited and the state of the vehicle interior switch 20 is monitored. Even when the vehicle is stopped, if the vehicle state changes due to an operation from outside the vehicle such as when a person approaches the vehicle or the door is locked or the vehicle door is opened, the power from the in-vehicle battery 10 is again applied. The state of the vehicle interior switch 20 can be monitored by supplying. If a person tries to get into the parked vehicle by the above external operation, the vehicle interior switch 20 may be operated after that. Therefore, the state of the vehicle interior switch 20 is monitored before the person gets on the vehicle, that is, before the operation. It is appropriate to do. Therefore, according to the present embodiment, it is possible to reliably prevent the function of monitoring the state of the vehicle interior switch 20 from being deteriorated.

  In the above embodiment, the state monitor of the vehicle interior switch 20 is monitored by the microcomputer 16 of the load ECU 12 by supplying power from the in-vehicle battery 10. The detection device 34 corresponds to the “predetermined sensor or switch” described in the claims, and the master ECU 30 executes the process of step 200 in the routine shown in FIG. The “person presence determination means” described in the above is executed when the microcomputer 16 executes the process of step 106, and the “state monitoring stop means” described in the claims of the claims is executed by executing the process of step 110. "Release means" described in the range is realized respectively.

  By the way, in the above-described embodiment, the master ECU 30 is made to determine whether there is an occupant in the vehicle interior using the occupant detection device 32, and whether there is a change in the vehicle state using the vehicle state detection device 34. Power is transmitted to the microcomputer 16 of the load ECU 12, and the microcomputer 16 controls the driving of the transistor 24 based on the information transmitted from the master ECU 30, thereby allowing the electric power from the in-vehicle battery 10 to be determined. The supply is executed or prohibited, and the state monitoring of the vehicle interior switch 20 is stopped or restarted. However, the method of stopping or restarting the state monitoring of the vehicle interior switch 20 by the microcomputer 16 is limited to this. Instead of the above, the following system may be used.

  That is, in addition to the configuration of the above embodiment, the ignition switch 26 is connected to the master ECU 30 to determine whether the IG contact and the ACC contact of the ignition switch 26 are on / off, and between the in-vehicle battery 10 and the load ECU 12. Is provided with a relay switch for connecting and disconnecting the connection. In such a configuration, the master ECU 30 determines whether or not there is an occupant in the vehicle interior using the occupant detection device 32 in the ignition off (IG contact off and ACC contact off) state, and the vehicle state detection device 34 is To determine whether there is a change in the vehicle state. Then, the master ECU 30 turns on the relay switch to execute power supply from the in-vehicle battery 10 to the load ECU 12 until no occupant is present in the vehicle compartment when the ignition is off, and causes the microcomputer 16 to execute the vehicle interior switch 20. When the occupant is no longer present in the vehicle interior, the relay switch is turned off to prohibit power supply from the in-vehicle battery 10 to the load ECU 12, and the vehicle interior switch 20 in the microcomputer 16. Stop monitoring the status of Further, when the state of the vehicle interior switch 20 is stopped by the microcomputer 16 and the vehicle state is changed due to an operation from the outside of the vehicle, the master ECU 30 turns on the relay switch to switch the vehicle-mounted battery 10 to the load ECU 12. The microcomputer 16 is restarted, and the microcomputer 16 is restarted to monitor the state of the vehicle interior switch 20.

  Also in the configuration of such a modified example, as in the above-described embodiment, the state of the vehicle interior switch 20 is monitored by supplying power from the vehicle-mounted battery 10 even in the ignition-off state, while in the ignition-off state. When there is no occupant in the passenger compartment during the switch state monitoring of the vehicle, the state monitoring of the vehicle interior switch 20 can be stopped by prohibiting the power supply from the in-vehicle battery 10 thereafter. It is possible to reduce the dark current in the ignition off state without deteriorating the function of monitoring the state of the indoor switch 20. Further, after the state monitoring of the vehicle interior switch 20 as described above is stopped, when the vehicle state changes due to an operation from the outside of the vehicle, the power supply from the in-vehicle battery 10 is performed again to monitor the state of the vehicle interior switch 20. Therefore, it is possible to reliably prevent the function of monitoring the state of the vehicle interior switch 20 from being deteriorated.

  In the above-described embodiment, only one load ECU 12 is provided, and a plurality of vehicle interior switches 20 are connected to the load ECU 12 to monitor the state thereof. However, a plurality of load ECUs 12 are connected via the in-vehicle LAN 36. It is also possible to provide one vehicle interior switch 20 to one load ECU 12.

It is a block diagram of the vehicle-mounted power supply system which is one Example of this invention. It is a time chart for demonstrating operation | movement of the vehicle-mounted power supply system of a present Example. It is a flowchart of an example of the control routine performed in the vehicle-mounted power supply system of a present Example.

Explanation of symbols

10 onboard battery 12 load ECU
16 Microcomputer 20 Car interior switch 26 Ignition switch 30 Master ECU
32 occupant detection device 34 vehicle state detection device

Claims (3)

A power supply system mounted on a vehicle including a state monitoring unit that can monitor the state of a vehicle interior switch by supplying power from an in-vehicle battery,
Person presence determination means for determining whether or not there is a person in the passenger compartment;
State monitoring stopping means for stopping the state monitoring of the vehicle interior switch by the state monitoring means by prohibiting power supply from the in-vehicle battery when it is determined by the person presence determining means that no passenger is present in the vehicle interior; ,
An in-vehicle power supply system comprising:   The state monitoring canceling means prohibits the power supply from the in-vehicle battery when the person presence determination means determines that no passenger is present in the vehicle compartment in the ignition-off state, so that the vehicle interior switch by the state monitoring means The in-vehicle power supply system according to claim 1, wherein the state monitoring is stopped.   The in-vehicle power supply system according to claim 1, further comprising: a release unit that cancels the stop of the state monitoring of the vehicle interior switch by the state monitoring stop unit when a state of a predetermined sensor or switch is changed.

Images