JP3981052B2 - Automotive control device - Google Patents

Description

  The present invention relates to an automotive control device that operates by being supplied with electric power from a vehicle-mounted battery via a key switch circuit and controls driving and stopping of the vehicle-mounted equipment.

A computing device miniaturized by IC technology is mounted on an automobile. An engine controller that controls the engine, an AT controller that controls the automatic transmission, a brake controller that controls the brake operation, a general-purpose controller that controls the navigation device and the in-vehicle audio device, and the like.
These control devices operate by being supplied with electric power from a vehicle-mounted battery via a key switch, and control driving, stopping, momentary operation state, etc. of the vehicle-mounted equipment in charge. Since the conventional control device is supplied with power from the vehicle battery via the key switch circuit, all the control devices are cut off from power supply and stopped at the same time as the key switch of the vehicle is turned off. The on-vehicle equipment whose ON / OFF is controlled by the operation is also stopped.

By the way, there is a case where it is desired to operate a specific in-vehicle facility after the key switch is turned off. For example, when it is desired to cool the engine room after the engine is stopped.
That is, simultaneously with turning off the key switch, the functions of the radiator and the cooling fan are stopped and the temperature of the engine room rises. The temperature rise in the engine room deteriorates the start of the engine when the fuel is vaporized in the fuel injection pump or the fuel pipe to generate bubbles and the engine is restarted after a short stop time. Such a problem has been raised in Japanese Patent Laid-Open No. 2-112611.
In Japanese Patent Laid-Open No. 2-112611, in order to solve such a problem, the radiator cooling fan is rotated in the reverse rotation state after the key switch is turned OFF until the temperature in the engine room becomes a predetermined value or less. The hot air in the engine room is discharged outside.
JP-A-2-112611

  However, there is no description about the power source of a controller (arithmetic unit) that performs 0N-OFF control of the radiator cooling fan. In order to continue the control of the radiator cooling fan even if the key switch is turned off, for example, it is considered that the controller is directly connected to the in-vehicle battery. In this case, however, the temperature in the engine room drops below a predetermined value. Even after the cooling fan is stopped, the controller continues to take out unnecessary current from the in-vehicle battery. As a result, the in-vehicle battery may rise by the time the key switch is turned on next time, which may hinder engine startup.

In addition to the method of directly connecting the control device to the in-vehicle battery, several methods for enabling the operation of the in-vehicle equipment after the key switch is turned off are considered, and these are summarized as follows.
(1) A control device in charge of controlling an in-vehicle facility to be operated is directly connected to the in-vehicle battery and operated regardless of ON / OFF of the key switch.
(2) A switch circuit with an OFF timer for supplying power directly from the in-vehicle battery to the in-vehicle equipment is provided, and at the same time the key switch is turned off, the OFF timer is activated.
(3) A control device dedicated to the on-vehicle equipment to be operated is provided, and this control device is directly connected to the on-board battery and operated regardless of ON / OFF of the key switch.

When it is desired to operate a specific in-vehicle facility after the key switch is turned OFF, the above three methods cause the following problems.
(1) When the control device in charge of controlling the in-vehicle equipment to be operated is directly connected to the in-vehicle battery, as described above, the control device continues to consume the electric power stored in the in-vehicle battery even after the key switch is turned off. There is a possibility that the in-vehicle battery will be discharged (raised) by the time the key is turned on next time.

On the other hand, (2) When a switch circuit with an OFF timer that directly supplies power from a vehicle-mounted battery to a specific vehicle-mounted facility is provided, the operation continues simply for a certain period of time, and detailed control that refers to the sensor output, etc. Can not do.
For example, if the exhaust fan that discharges hot air in the engine room to the outside is controlled by the OFF timer, the exhaust fan is operated even when the temperature in the engine room is low and cooling is not required, and the battery capacity is wasted. Is done.
Furthermore, the addition of a timer, securing of a timer installation location, a significant change in wiring, and the like cause a cost time increase.
In addition, (3) When a control device dedicated to the on-vehicle equipment that is to be operated is provided, the power taken out from the on-vehicle battery can be suppressed by using a power saving program or the like. The wiring state and the connection relationship with existing sensors and control devices are also complicated.

  The present invention has a circuit configuration for continuing the control of an in-vehicle facility after the key switch is turned off, and requires less power to be taken from the in-vehicle battery to operate a specific in-vehicle facility after the key switch is turned off. The object is to provide a control device for an automobile in which additions and changes of programs are minimized.

FIG. 1 is an explanatory diagram of the configuration of the present invention.
The invention according to claim 1 is an automotive control device having an arithmetic unit 14 that operates by being supplied with electric power from a vehicle-mounted battery 11 via a key switch circuit 12 and controls driving and stopping of the vehicle-mounted equipment 13. A switching circuit 15 that is disposed between the arithmetic devices 14 and that can supply bypass power to the arithmetic device 14 itself according to a command from the arithmetic device 14 is provided, and the self-power supply control program is stored in the arithmetic device, Even after the key switch circuit 12 is turned off, the power supply for bypass via the switching circuit 15 is continued to operate the arithmetic unit 14.

That is, the self-power supply control program executes a first calculation process for identifying ON / OFF of the key switch circuit 12 and until a first predetermined time elapses after it is determined that the key switch circuit 12 is OFF in the first calculation process. a second arithmetic processing to continue the bypass power supply via the switching circuit 15, before after the first predetermined time has elapsed, if the further second predetermined time has elapsed, or when the second predetermined time elapses However, when it is determined that the driving of the in-vehicle equipment is unnecessary, the third arithmetic processing for turning off the switching circuit 15 is included.

  According to a second aspect of the present invention, there is provided a control apparatus for an automobile in which the switching circuit 15 in the configuration of the first or second aspect is configured by a switching transistor controlled by the arithmetic device 14 and is housed in the same unit of the arithmetic device 14. .

In FIG. 1, in the vehicle control device according to claim 1, even after the operator operates the key switch of the vehicle to turn off the key switch circuit 12, the calculation device 14 is supplied by bypass power supply through the switching circuit 15. It continues to operate as it is. The arithmetic device 14 continues to control the driving, stopping, momentary operation state, etc. of the in-vehicle equipment 13 in accordance with the stored control program.
Then, after the key switch is turned off, when the predetermined operation of the in-vehicle equipment 13 is completed, the switching circuit 15 is turned off by the power supply control program, and the arithmetic device 14 stops its power consumption.
Therefore, even after the key switch is turned off, the arithmetic unit 14 can perform fine control on the in-vehicle equipment 13 according to the output of the sensor and other devices. After the power supply control program turns off the switching circuit 15, all functions and power consumption of the computing device 14 are maintained in a completely stopped state as before until the operator turns on the key switch again.

More specifically, the self-power supply control program continues to control the on-vehicle equipment 13 that is ON / OFF controlled depending on the situation. However, one limit of control continuation after the key switch is turned off is limited by the timer counting process on the program. It is set as the first predetermined time .
The arithmetic unit 14 identifies that the key switch circuit 12 is OFF, and starts the timer counting process when it is OFF. The computing device 14 identifies whether or not the first predetermined time has elapsed, and continues the on-off control of the in-vehicle equipment 13 if it has not elapsed.
That is, the arithmetic unit 14 continues to monitor the situation even after the on-vehicle equipment 13 is turned off within a predetermined time range, and immediately turns on the on-vehicle equipment 13 when it is necessary to turn it on.
Then, after the first predetermined time has elapsed, the timer counting process is further performed, and if the on-vehicle equipment 13 needs to be controlled, the switching circuit 15 is continuously turned on until the second predetermined time elapses. If it is determined that driving the on-vehicle equipment is unnecessary even before the passage, the switching circuit 15 is turned OFF at that time.

Therefore, according to the first aspect of the present invention, even after the key switch is turned OFF, the necessary control of the in-vehicle equipment can be continued by “the same fineness as before the key switch is turned OFF” by the arithmetic device. After the necessary control of the in-vehicle equipment is completed, the arithmetic unit turns off the switching circuit and stops its own power consumption. Thus, unnecessary consumption of the in-vehicle battery capacity can be avoided as before, and the engine restarts. Will not be adversely affected.
Changes in the device configuration and circuit configuration necessary for obtaining such functions are minimal, and there is no need to add a sensor or timer as a dedicated device. The control program that is run by the arithmetic unit can also be added with a few steps, and the normal control steps before the key switch OFF can be used for many of the steps necessary for the control after the key switch OFF.
And combined with the timer counting process, for a predetermined time after the key switch is turned off, the situation monitoring is continued even after the on-vehicle equipment is turned off. it can.

In the vehicle control device according to the second aspect, power is supplied to the arithmetic device through the switching circuit constituted by the switching transistor.
Since the switching circuit is constituted by a transistor circuit and stored in the unit of the arithmetic unit, it is not necessary to change the wiring relating to the switching circuit outside the unit. Therefore, mounting on an existing vehicle body is easy.

  Next, embodiments of the present invention will be described by way of examples.

The engine room fan control of the first embodiment will be described with reference to FIGS. 2 is an explanatory diagram of a device configuration of the first embodiment, FIG. 3 is a circuit diagram, FIGS. 4 and 5 are flowcharts of arithmetic processing, and FIG. 6 is a time chart of fan control.
In FIG. 5, (a) is an extended timer process, and (b) is a timer count process.
In FIG. 6, (a) shows the case of rapid cooling, and (b) shows the case of slow cooling.

In FIG. 2, the engine room 20 is provided under the floor of a passenger compartment of a one-box type automobile (not shown) and stores the engine 24 and the automatic transmission 25. An engine room fan 21 is installed approximately at the center of the vehicle body of the engine room 20. The engine room fan 21 forcibly exhausts high-temperature air accumulated in the engine room 20 to the outside, and causes cold outside air to enter the engine room 20.
An engine room temperature sensor 22 is disposed in the engine room 20. The engine room temperature sensor 22 outputs an analog signal corresponding to the temperature level of the engine room 20.

  A control unit 23 is arranged in a vehicle compartment (not shown). The control unit 23 is an arithmetic device that mainly executes a comprehensive control program for the engine 24, and is connected to a plurality of sensors 28 and a plurality of inputs / outputs 28 that are provided in the engine 24 and are directed to attached equipment. The control unit 23 is connected to the battery 27 via the key switch 26 and operates by receiving power supply from the battery 27. The control unit 23 starts to be activated as soon as the key switch 26 is turned on.

  The control unit 23 controls ON / OFF of the engine room fan 21 according to the engine room fan control program inserted into the engine control program. Even after the key switch 26 is turned off, the control unit 23 receives power supply from the battery 27 through the bypass line 27B and continues to control the engine room fan 21.

In FIG. 3, the control unit 23 includes a calculation unit 31, a power supply circuit 32, a key switch reading circuit 33, a power connection / disconnection circuit 34, an AD converter 36, a driver 35, and the like. The power supply circuit 32 inputs power supplied from the battery 27 and outputs a power supply voltage of 5V. The computing unit 31 operates with a 5 V power supply voltage output from the power supply circuit 32. The AD converter 36 converts the analog output of the engine room temperature sensor 22 into a digital value and inputs the digital value to the calculation unit 31.
The calculation unit 31 identifies the air temperature in the engine room 20 from the output of the engine room temperature sensor 22 input via the AD converter 36. When the air temperature exceeds a predetermined limit value (ON set value), the engine room fan 21 starts to operate, and when the air temperature falls into another limit value (OFF set value), the engine room fan 21 is stopped.
That is, when the arithmetic unit 31 turns on the driver 35 and the fan relay 21R is turned on, the engine room fan 21 is turned on. Then, the engine room fan 21 is turned off when the calculation unit 31 turns off the driver 35. The engine room fan 21 is directly connected to the output of the battery 27.

  The computing unit 31 identifies ON / OFF of the key switch 26 from the output of the key switch reading circuit 33. During the period when the key switch 26 is turned on, the voltage at the connection point of the stacks of the resistors R1 and R2 is suppressed to an excessive voltage by the Zener diode D1 and is maintained at the H level. When the key switch 26 is turned off, the diode D2 blocks the voltage on the bypass line 27B side, and the entire stack of the resistors R1 and R2 becomes L level.

The output voltage of the battery 27 through the bypass line 27B is input from the diode D3 to the power supply circuit 32 through the transistor T2 if the transistor T2 is in the ON state. In addition, the transistor T2 is turned on when the calculation unit 31 turns on the transistor T1.
That is, during the period in which the transistor T2 is turned on, the power supply circuit 32 continues to output a power supply voltage of 5 V by supplying power from the bypass line 27B through the power supply disconnection circuit 34 even when the key switch 26 is turned off. As a result, the calculation unit 31 continues to function, and the engine room fan 21 can be controlled in the same manner as before the key switch 26 is turned off.

  The calculation unit 31 executes various calculation processes using a large number of other inputs in accordance with the stored calculation program, and forms a large number of other outputs. The control program for the engine room fan 21 occupies a part of the arithmetic program stored in the arithmetic unit 31.

In FIG. 4, when the key switch 26 of FIG. 3 is turned on, a control program for the engine room fan 21 is started together with a program for executing the other control 206. In step 201, the power connection / disconnection circuit 34 (transistor T1) is turned on, and initial values are taken into the cooling timer and the extension timer executed on the program.
Therefore, thereafter, the power supply voltage of the power supply circuit 32 is maintained and the calculation unit 31 continues to function until the calculation unit 31 turns off the power supply / disconnection circuit 34 (transistor T1).
The cooling timer is a time for monitoring the temperature rise in the engine room 20 after the key switch 26 is turned off and continuing to control the fan 21. In the cooling timer, 300 counts corresponding to 5 minutes is set as an initial value.
The extension timer is a time for which the control of the fan 21 is continued when the cooling of the engine room 20 is not completed when the cooling timer expires. The extension timer is also set with an initial value of 300 counts corresponding to 5 minutes.

In step 202, the output of the engine room temperature sensor 22 is captured and the temperature ART of the engine room 20 is identified.
If it is determined in step 203 that the temperature ART is equal to or higher than the ON set value, the engine room fan 21 is started in step 204.
On the other hand, when it is determined in step 203 that the temperature ART is less than the ON set value, and in the next step 210, it is determined that the temperature ART is less than the OFF set value, the engine room fan 21 is stopped in step 211.
On the other hand, if it is determined in step 210 that the value is equal to or larger than the OFF set value, step 211 is bypassed and the process proceeds to step 205 as it is. As a result, the engine room fan 21 is maintained in the ON state.

In step 205, ON / OFF of the key switch 26 is identified. When the key switch is ON, other normal control 206 is executed.
On the other hand, when the key switch 26 is OFF, control using a cooling timer and an extension timer is executed.
At step 212, a distinction between mid-counting / time-up in the cooling timer is identified.
If the cooling timer is in the middle of counting, the processes of steps 202 to 205 and 210 to 211 are repeated. That is, during the counting of the cooling timer, the engine room fan 21 is maintained in the ON state or turned off based on the feedback whether or not the temperature ART from the engine room temperature sensor 22 is equal to or higher than the OFF set value. .
When the cooling timer expires, the temperature ART of the engine room 20 is compared with the OFF set value.

Here, if the temperature ART of the engine room 20 is less than the OFF set value, it means that the cooling is completed. In step 214, the power connection / disconnection circuit 34 is turned OFF, and the functions of the entire control unit 23 including the calculation unit 31 are Stop power consumption.
On the other hand, if the temperature ART of the engine room 20 is equal to or higher than the OFF setting value, it means that the cooling is insufficient, and the continuation of the engine room fan 21 control by the extension timer is selected.

That is, the distinction between counting halfway / time-up in the extension timer is identified in step 221 of FIG. 5A, and if the extension timer is in the middle of counting, the processing in steps 202 to 205 and 210 to 211 is repeated. Therefore, the engine room fan 21 is maintained in the ON state or turned off based on the feedback from the engine room temperature sensor 22 even during the count of the extension timer.
On the other hand, when the extension timer expires, the power connection / disconnection circuit 34 is immediately turned OFF at that time, and the function and power consumption of the entire control unit 23 including the calculation unit 31 are stopped.

During the process shown in FIGS. 4 and 5A, the interrupt process shown in FIG. 5B is executed every second. The interrupt process of FIG. 5B starts the count of the cooling timer when the key switch 26 is turned off, and starts the count of the extension timer when the cooling timer expires.
In step 222, ON / OFF of the key switch 26 is identified. When the key switch is ON, the count values of the cooling timer and the extension timer are not changed and are maintained at the initial values.
On the other hand, if the key switch 26 is OFF, the count value of the cooling timer is decremented by 1 every second in step 225 until the time-out of the cooling timer is identified in step 223. After the cooling timer time-up is identified in step 223, the count value of the cooling timer is decreased by 1 every second in step 226 until the extension timer time-out is identified in step 224.

The actual operation of the engine room fan 21 configured and controlled in this way will be described with reference to FIGS.
In (a), the temperature of the engine room 20 exceeds the ON set value during the period in which the key switch 26 is in the ON state (during driving and running), and the engine room fan 21 is activated. The key switch 26 was turned off after the temperature in the engine room 20 reached a steady state due to the effect of the engine room fan 21.
After the key switch 26 is turned off, the engine room fan 21 is stopped when the temperature in the engine room 20 becomes less than the OFF set value, and then the power connection / disconnection circuit 34 is turned off when the cooling timer expires. Is done.
In this case, since the temperature in the engine room 20 is lower than the OFF setting value when the cooling timer expires, the extension timer is not started.

In (b), after the key switch 26 is turned OFF, the temperature of the engine room 20 exceeds the ON set value, and the engine room fan 21 is activated. In this case, the temperature in the engine room 20 continues to rise even after the engine room fan 21 is activated, and the temperature in the engine room 20 still exceeds the OFF set value when the cooling timer expires.
Therefore, the count of the extension timer is started following the time-up of the cooling timer, and the engine room fan 21 is stopped because the temperature in the engine room 20 becomes less than the OFF set value before the time-up of the extension timer. Immediately, the power connection / disconnection circuit 34 is turned off.

  Even when the temperature in the engine room 20 is delayed and the extension timer times out, the engine room fan 21 and the power connection / disconnection circuit 34 are immediately turned off even when the temperature in the engine room 20 is equal to or higher than the OFF set value. And try to avoid further consumption of the battery.

  According to the engine room fan control of the first embodiment configured as described above, since the temperature rise of the engine room after the key switch is turned off is suppressed, there is no fear of fuel vaporizing in the fuel pump or the pipe. The problem that the engine is difficult to start when the engine is restarted is solved.

Also, the control unit judges the temperature rise in the engine room and starts the engine room fan, and judges the temperature drop in the engine room and stops the engine room fan. Compared to the case where the room fan is operated, finer control can be performed in accordance with the actual situation.
That is, the engine room fan is not operated even when the temperature of the engine room is low, and the battery capacity is not wasted. The engine room fan does not continue to operate meaninglessly after the engine room has been cooled.
Conversely, if engine room cooling is delayed because the key switch was turned off immediately after high-temperature, high-output operation for a long time, etc., the engine room fan should be operated until the temperature actually decreases. Continued to ensure the effectiveness of engine room cooling.

  Further, since the fan stop temperature is set lower than the fan start temperature and the hysteresis characteristic is given to the operation of the engine room fan, a temperature rise and a temperature fall are detected instead of a simple temperature level. As a result, the start-up is surely performed in the process of increasing the engine room temperature, while the cool-down process is left to natural cooling to eliminate meaningless start-up. At the same time, it is possible to avoid repeated ON-OFF of the engine room fan.

  Furthermore, since the control is stopped using the cooling timer and the power supply of the control unit itself is also turned off, after the power supply is turned off, the control unit The associated sensor consumes no power and does not drain battery capacity. Therefore, there is no fear that the battery will rise even after a long stoppage period.

Further, when the necessary temperature drop cannot be obtained within the set time of the cooling timer, the extension timer is started and the engine room cooling is continued by feedback, so that the engine room cooling is ensured. Compared with the case where the cooling timer is set for a long time from the beginning, there is no useless waiting state of the control unit when the cooling is completed earlier, and the power can be cut off earlier to save power.
Also, if the cooling is not completed when the extension timer expires, the control unit is immediately turned off to avoid further battery capacity consumption. In such a case, since it is considered that there is a special reason such as an abnormally high outside air temperature, there is no benefit of continuing to operate the engine room fan indefinitely.

An engine room cooling system having such a function can be implemented by adding a few parts to the existing configuration and adding a few program steps in the control unit.
Since the cooling timer and extension timer are implemented by program execution, the added components are only a circuit for supplying power by bypass and a circuit for detecting the key switch OFF. A power line that does not pass through the switch is only provided between the battery and the control unit, and no change is required for the engine room fan and its ON-OFF control circuit.
Further, the program steps to be added are only the timer counting process and the ON / OFF function of the bypass circuit, and no change is necessary for the ON / OFF control function of the engine room fan.

In the first embodiment, the engine room fan is controlled by the control unit even after the key switch is turned off. However, the on-board load to be controlled is not limited to the engine room fan. For example, by detecting the darkness of the outside world and turning on the foot lighting for a certain period of time, it is possible to ensure the convenience when the driver leaves the car, or when the driver detects slipping of the car body or rolling of the wheel, It is good also as an alarm process which requires countermeasures before leaving.
The first embodiment is engine room cooling in a one-box body automobile, but the same cooling operation is performed for a general sedan type structure in which the engine is stored in the hood and other engine rooms. May be.

FIG. 7 is an explanatory diagram of engine room fan control of the second embodiment. Here, the engine room fan is controlled in the same way as in the first embodiment, but the element that turns on and off the bypass power supply is the relay 54.
In FIG. 7, the calculation unit 51 is operated by a 5 V power supply voltage supplied from the power supply circuit 52. In addition to the line 52A for supplying the battery output voltage through the key switch 46, a line 52B for supplying the battery output voltage through the relay 54 is connected to the power supply circuit 52.
The contact of the relay 54 is connected when the calculation unit 51 turns on the driver 56. The computing unit 51 ensures that the control of the engine room fan 41 can be continued when the key switch 46 is turned on and the driver 56 is turned on at any time when the key switch 46 is turned off.

  The engine room fan 41 driven by the battery voltage is activated when the calculation unit 51 turns on the driver 55 and is stopped when the driver 55 is turned off.

In the engine room fan control of the second embodiment configured as described above, control of the engine room fan 41 is continued even after the key switch 46 is turned off to ensure the effectiveness of engine room cooling. Then, the control is completed when the cooling of the engine room is completed or the set time elapses, and the relay 54 is turned off by itself to avoid wasting battery capacity.
Therefore, the same effect as the first embodiment can be obtained.

It is explanatory drawing of the structure of this invention. It is explanatory drawing of the apparatus structure of 1st Example. 1 is a circuit diagram of a first embodiment. It is a flowchart of a calculation process. It is a flowchart of a calculation process. It is a time chart of fan control. It is explanatory drawing of the engine room fan control of 2nd Example.

Explanation of symbols

11 On-board battery
DESCRIPTION OF SYMBOLS 12 Key switch circuit 13 In-vehicle equipment 14 Arithmetic device 15 Switching circuit 21, 41 Engine room fan 22 Engine room temperature sensor 23 Control unit 24 Engine 25 Automatic transmission 26, 46 Key switch 27 Battery 28 Other input / output 31, 51 Calculation unit 32 , 52 Power supply circuit 33, 53 Key switch reading circuit 34 Power connection / disconnection circuit 35, 55, 56 Driver 36 AD converter 21R, 54 Relay 27B, 52B Bypass line R1, R2 Resistor D1, D2, D3 Diode T1, T2 Transistor

Claims (2)

In an automotive control device having an arithmetic unit that operates by being supplied with electric power from a vehicle battery via a key switch circuit and controls driving and stopping of the vehicle equipment,
A switching circuit is provided between the in-vehicle battery and the arithmetic device, and is capable of supplying bypass power to the arithmetic device itself according to a command from the arithmetic device,
A self-power supply control program is stored in the arithmetic device,
The self-power control program is
A first calculation process for identifying ON / OFF of the key switch circuit;
A second arithmetic processing to continue the bypass power supply via said switching circuit to the first predetermined time has elapsed after the OFF judgment of the key switch circuit in the first arithmetic processing,
When the second predetermined time has elapsed after the first predetermined time has elapsed, or when it is determined that driving of the on-vehicle equipment is unnecessary even before the second predetermined time has elapsed, And a third arithmetic process for turning off the switching circuit. 2. The automotive control device according to claim 1, wherein the switching circuit includes a switching transistor controlled by the arithmetic device, and is housed in the same unit of the arithmetic device.

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