JP7342804B2 - electronic control unit - Google Patents

Description

The present disclosure relates to an electronic control device that detects disconnection.

Patent Document 1 includes a first power supply line and a second power supply line connected to an external power supply, and a current inspection unit that detects a disconnection of the first power supply line. A controller configured to automatically enable the line is described.

Patent No. 6388932

In order to detect a disconnection of the first power line in the control device described in Patent Document 1, the control device starts up under normal control and transmits the amount of current requested by the control device to the current testing unit via the first power line. It needs to flow. Therefore, when detecting a disconnection for the first time, a current flows through the second power supply line before the power supplied to the actuator is limited. However, when a large current is required while the control device is placed in a high-temperature environment, the connector terminals generate heat due to the energized current, which may cause the connector terminals to exceed their allowable temperature, causing the connector terminals to melt.

For example, in a vehicle where the first power supply line is disconnected while the vehicle is running or after the vehicle has stopped, the above problem may occur if the vehicle is restarted immediately after the IG is turned off or when the temperature inside the control device is high due to dead soak. may occur.

The present disclosure aims to detect disconnection without flowing a large current.

One aspect of the present disclosure is an electronic control device (4) that controls a vehicle by being supplied with power supply voltage from an external power supply (5), and includes a plurality of power supply lines (21, 22, 23) and a current detection (25, 26, 27, 28, 29, 30), a current path for current detection (24), and a detection switch (31).

The plurality of power supply lines are connected to an external power supply and supply a power supply voltage from the external power supply.
The current detection section is configured to detect a plurality of power supply currents flowing through each of the plurality of power supply lines.

The current path for current detection is installed between a location downstream of the current detection section and the ground, and a power supply current flows through the current path.

The detection switch switches the current path for current detection between a conduction state and a cutoff state.
The electronic control device of the present disclosure configured in this manner is supplied with a power supply voltage from an external power supply via a plurality of power supply lines. Therefore, the electronic control device of the present disclosure can control the vehicle by receiving the power supply voltage from the external power supply unless disconnection occurs in all of the plurality of power supply lines.

Further, the electronic control device of the present disclosure can switch a current detection current path installed downstream of the plurality of power supply lines between a conductive state and a cutoff state using a detection switch. When the current detection current path is in a conductive state, a plurality of power supply currents flow through each of the plurality of power supply lines. At this time, the current detection unit detects the power supply current flowing through each of the plurality of power supply lines, so that the electronic control device of the present disclosure can detect whether or not the plurality of power supply lines are disconnected.

The electronic control device of the present disclosure makes the current detection current path conductive with the detection switch, thereby determining the time during which a plurality of power supply currents are flowing through each of the plurality of power supply lines, from the on state of the detection switch. Adjustment can be made by switching to the off state. That is, the electronic control device of the present disclosure can reduce the plurality of power supply currents flowing through each of the plurality of power supply lines as the time period during which the detection switch is continuously turned on is shortened. Therefore, the electronic control device of the present disclosure can detect disconnection without flowing a large current.

FIG. 1 is a block diagram showing the configuration of a vehicle control system according to a first embodiment. 7 is a flowchart showing a boosting execution process according to the first embodiment. 5 is a timing chart showing a boosting operation of the first embodiment. FIG. 2 is a block diagram showing the configuration of a vehicle control system according to a second embodiment. 7 is a flowchart showing a boosting execution process according to the second embodiment. 7 is a timing chart showing a boosting operation of the second embodiment. FIG. 3 is a block diagram showing the configuration of a vehicle control system according to a third embodiment. 12 is a flowchart showing a boosting execution process according to a third embodiment. 7 is a timing chart showing a boosting operation in a third embodiment.

[First embodiment]
A first embodiment of the present disclosure will be described below with reference to the drawings.
The vehicle control system 1 of this embodiment is mounted on a vehicle, and includes an engine speed control device 2, a fuel injection device 3, an electronic control device 4, and a battery 5, as shown in FIG.

Engine speed control device 2 controls the engine speed of an engine mounted on a vehicle. The fuel injection device 3 injects fuel into each cylinder of the engine based on the state of the engine.

The electronic control device 4 controls the engine speed control device 2 and the fuel injection device 3.
Battery 5 supplies battery voltage Vb to electronic control device 4 . The battery 5 includes a first power output terminal 101, a second power output terminal 102, and a third power output terminal 103 that output a battery voltage Vb.

The electronic control device 4 includes a first power input terminal 11 , a second power input terminal 12 , a third power input terminal 13 , a first signal output terminal 14 , a second signal output terminal 15 , and a microcomputer 16 . , a fuel injection drive IC 17, a detection section 18, a boost section 19, and a power supply pass capacitor 20.

The first, second, and third power input terminals 11, 12, and 13 are connected to the first, second, and third power output terminals 101, 102, and 103. As a result, the battery voltage Vb is applied to the first, second, and third power input terminals 11, 12, and 13.

The first signal output terminal 14 is connected to the engine speed control device 2 . The second signal output terminal 15 is connected to the fuel injection device 3.
The microcomputer 16 includes a CPU, ROM, RAM, and the like. Various functions of the microcomputer 16 are realized by the CPU executing programs stored in a non-transitive physical recording medium. In this example, the ROM corresponds to a non-transitive physical recording medium that stores a program. Furthermore, by executing this program, a method corresponding to the program is executed. Note that part or all of the functions executed by the CPU may be configured in hardware using one or more ICs. Furthermore, the number of microcomputers constituting the electronic control device 4 may be one or more.

The microcomputer 16 outputs an engine speed control signal for controlling the engine speed of the engine to the engine speed control device 2 via the first signal output terminal 14. Further, the microcomputer 16 outputs a fuel injection control signal for controlling the plurality of injectors included in the fuel injection device 3 to the fuel injection drive IC 17.

Based on the fuel injection control signal from the microcomputer 16, the fuel injection drive IC 17 sends a fuel injection drive signal to the fuel injection device via the second signal output terminal 15 to drive the plurality of injectors included in the fuel injection device 3. Output to 3.

The detection unit 18 includes a first power line 21, a second power line 22, a third power line 23, a current detection current path 24, a first current detection resistor 25, a second current detection resistor 26, It includes a third current detection resistor 27, a first comparator 28, a second comparator 29, a third comparator 30, a disconnection detection switch 31, and a disconnection detection capacitor 32.

The first power line 21 has one end connected to the first power input terminal 11 and the other end connected to one end of the power supply pass capacitor 20 . Note that the other end of the power supply pass capacitor 20 is grounded.
The second power line 22 has one end connected to the second power input terminal 12 and the other end connected to one end of the power supply pass capacitor 20 .

The third power supply line 23 has one end connected to the third power supply input terminal 13 and the other end connected to one end of the power supply pass capacitor 20 .
One end of the current detection current path 24 is connected to one end of the power supply pass capacitor 20, and the other end is grounded.

The first current detection resistor 25 is installed on the first power supply line 21 . The second current detection resistor 26 is installed on the second power supply line 22. The third current detection resistor 27 is installed on the third power supply line 23. The first, second, and third current detection resistors 25, 26, and 27 are shunt resistors.

The first comparator 28, the second comparator 29, and the third comparator 30 have a first input terminal, a second input terminal, and an output terminal. The first, second, and third comparators 28, 29, and 30 calculate a subtraction value by subtracting the voltage value applied to the second input terminal from the voltage value applied to the first input terminal, and add the subtraction value to the subtraction value. An analog signal having a corresponding voltage value is output from the output terminal. Hereinafter, the analog signals output from the first, second, and third comparators 28, 29, and 30 will be referred to as first, second, and third voltage detection signals, respectively.

One end of the first current detection resistor 25 is connected to the first input terminal of the first comparator 28, and the other end of the first current detection resistor 25 is connected to the second input terminal of the first comparator 28. The microcomputer 16 is connected to the output terminal of the 1 comparator 28.

One end of the second current detection resistor 26 is connected to the first input terminal of the second comparator 29, the other end of the second current detection resistor 26 is connected to the second input terminal of the second comparator 29, and the second current detection resistor 26 is connected to the second input terminal of the second comparator 29. The microcomputer 16 is connected to the output terminal of the comparator 29.

One end of the third current detection resistor 27 is connected to the first input terminal of the third comparator 30, the other end of the third current detection resistor 27 is connected to the second input terminal of the third comparator 30, and the other end of the third current detection resistor 27 is connected to the second input terminal of the third comparator 30. The microcomputer 16 is connected to the output terminal of the three comparators 30.

The disconnection detection switch 31 is installed on the current detection current path 24 . The disconnection detection switch 31 is switched between an on state and an off state according to a switch control signal from the microcomputer 16.

The disconnection detection capacitor 32 is installed on the current detection current path 24 downstream of the disconnection detection switch 31.
The booster 19 includes a diode 41, a switching element 42, a capacitor 43, an inductor 44, resistors 45, 46, 47, and a capacitor 48.

The diode 41 has a cathode connected to one end of the capacitor 43 and an anode connected to the drain of the switching element 42 .
The switching element 42 is an N-channel field effect transistor, and has a drain connected to the anode of the diode 41 and a source grounded via a resistor 45. Further, the gate of the switching element 42 is connected to the fuel injection drive IC 17 via a resistor 46. The fuel injection drive IC 17 outputs a boost control signal to the gate of the switching element 42 to switch the switching element 42 between an on state and an off state.

The capacitor 43 has one end connected to the cathode of the diode 41 and the other end grounded. The capacitor 43 is an electrolytic capacitor with a large capacitance so that the power supply can be sufficiently smoothed.

The inductor 44 has one end connected to the anode of the diode 41, and the other end connected to the first, second, and third power input terminals 11, 12, and 13 via the first, second, and third power supply lines 21, 22, and 23. be done.

The resistor 47 has one end connected to the source of the switching element 42 and the other end connected to the fuel injection drive IC 17. One end of the capacitor 48 is connected to the fuel injection drive IC 17, and the other end is grounded.

Next, the procedure of the boost execution process executed by the microcomputer 16 will be explained. The boost execution process is a process that is started immediately after the battery voltage Vb is applied to the electronic control device 4 and the microcomputer 16 is started.

When the boost execution process is executed, the microcomputer 16 first switches the disconnection detection switch 31 from the off state to the on state in S10, as shown in FIG.
Then, in S20, the microcomputer 16 repeatedly acquires the first, second, and third voltage detection signals from the first, second, and third comparators 28, 29, and 30 until the preset switch-on time elapses, The voltage values indicated by the first, second, and third voltage detection signals are stored in the RAM. Then, when the switch-on time has elapsed, the microcomputer 16 ends the process of S20.

When the process of S20 is completed, the microcomputer 16 switches the disconnection detection switch 31 from the on state to the off state in S30.
Next, the microcomputer 16 determines whether a disconnection has been detected based on the voltage value stored in the RAM.

Specifically, the microcomputer 16 determines the switch-on time based on the voltage values indicated by the first, second, and third voltage detection signals and the resistance values of the first, second, and third current detection resistors 25, 26, and 27. The values of the first, second, and third detection resistor currents flowing through the first, second, and third current detection resistors 25, 26, and 27 during this period are calculated.

Then, the microcomputer 16 determines whether the maximum values of the first, second, and third detection resistor current values within the switch-on time are equal to or less than the first, second, and third disconnection judgment values J1, J2, and J3, respectively, set in advance. to judge.

Then, the microcomputer 16 determines that when the maximum value of the first detection resistor current value is less than or equal to the first disconnection judgment value J1, a disconnection occurs in the first current path through which the current flows from the first power input terminal 11 to the booster 19. judge that it is.

Further, the microcomputer 16 determines that when the maximum value of the second detection resistor current value is less than or equal to the second disconnection determination value J2, a disconnection occurs in the second current path through which the current flows from the second power input terminal 12 to the booster 19. judge that it is.

Further, the microcomputer 16 determines that when the maximum value of the third detection resistor current value is less than or equal to the third disconnection judgment value J3, a disconnection occurs in the third current path through which the current flows from the third power input terminal 13 to the booster 19. judge that it is.

Here, if a disconnection is not detected, the microcomputer 16 moves to S60. On the other hand, if a disconnection is detected, the microcomputer 16 first calculates an appropriate engine speed and boost current value in order to suppress the boost current flowing through the boost unit 19 in S50. Further, in S50, the microcomputer 16 outputs an engine speed control signal indicating the calculated engine speed to the engine speed control device 2, so that a boost current having the calculated boost current value flows through the fuel injection device 3. A fuel injection control signal for driving is output to the fuel injection drive IC 17. When the process of S50 is completed, the microcomputer 16 moves to S60.

When proceeding to S60, the microcomputer 16 causes the fuel injection drive IC 17 to start the pressure increasing operation by the pressure increasing section 19. Then, in S70, the microcomputer 16 determines whether the boosting operation by the boosting section 19 has been completed.

Here, if the boosting operation is not completed, the microcomputer 16 repeats the process of S70 to wait until the boosting operation is completed. When the boosting operation is completed, the microcomputer 16 determines in S80 whether the vehicle starting state continues. Specifically, the microcomputer 16 determines that the vehicle activation state continues when the vehicle activation signal input from the vehicle is at a high level, and determines that the vehicle activation state continues when the vehicle activation signal is at a low level. , it is determined that the vehicle starting state is not continuing.

Here, if the vehicle starting state continues, the microcomputer 16 moves to S60. On the other hand, if the vehicle starting state is not continuing, the microcomputer 16 ends the boosting execution process.

FIG. 3 is a timing chart showing a boosting operation when a disconnection occurs in the first current path.
As shown in FIG. 3, the vehicle activation signal is at a low level at time t0. The vehicle starts, and the vehicle start signal changes from low level to high level at time t1. As the vehicle activation signal changes to high level, the disconnection detection switch 31 is switched from the off state to the on state at time t2. Further, at time t3, the disconnection detection switch 31 is switched from the on state to the off state.

As a result, current flows in the second current path and the third current path between time t2 and time t3. As the current flows through the second current path and the third current path, the voltage of the disconnection detection capacitor 32 (hereinafter referred to as capacitor charging voltage) increases between time t2 and time t3.

Then, the microcomputer 16 determines whether the maximum values of the first, second, and third detection resistance current values between time t2 and time t3 are equal to or less than the first, second, and third disconnection judgment values J1, J2, and J3, respectively. to judge. Here, since the maximum value of the first detection resistor current value is less than or equal to the first disconnection determination value J1, the microcomputer 16 determines that a disconnection has occurred in the first current path.

Then, between time t3 and time t4, the microcomputer 16 calculates an appropriate engine speed and boost current value to suppress the boost current. As a result, the boosting operation is performed with the boosting current being suppressed between time t4 and time t5.

When the boosted voltage is used at time t6, the boosting operation is performed again between time t7 and time t8 with the boosted current being suppressed in order to charge the reduced boosted voltage. The operations from time t4 to time 7 are repeatedly executed as long as the vehicle starting state continues.

The electronic control device 4 configured in this manner controls the vehicle by being supplied with the battery voltage Vb from the battery 5, and connects the first, second, and third power lines 21, 22, and 23 with the first, second, and third power lines. It includes current detection resistors 25, 26, and 27, first, second, and third comparators 28, 29, and 30, a current path 24 for current detection, and a switch 31 for disconnection detection.

The first, second, and third power lines 21, 22, and 23 are connected to the battery 5 and supply the battery voltage Vb from the battery 5.
The first, second, and third current detection resistors 25, 26, and 27 and the first, second, and third comparators 28, 29, and 30 are connected to the first, second, and third current detection resistors 25, 26, and 27, and the 2, 3 Detection resistor Detects current.

The current path 24 for current detection is a current detection circuit in which first, second, and third comparators 28, 29, and 30 detect the first, second, and third detection resistor currents in the first, second, and third power supply lines 21, 22, and 23. It is installed between a location downstream of the first, second, and third current detection resistors 25, 26, and 27 and the ground, and current flows through the first, second, and third detection resistors.

The disconnection detection switch 31 switches the current detection current path 24 between a conductive state and a cutoff state.
In this way, the electronic control device 4 is supplied with the battery voltage Vb from the battery 5 via the first, second, and third power lines 21, 22, and 23. Therefore, the electronic control device 4 can control the vehicle by receiving the battery voltage Vb from the battery 5 unless disconnection occurs in all of the first, second, and third power lines 21, 22, and 23. .

Furthermore, the electronic control device 4 uses the disconnection detection switch 31 to switch the current detection current path 24 installed downstream of the first, second, and third power supply lines 21, 22, and 23 between a conductive state and a cutoff state. Can be switched. When the current detection current path 24 is in a conductive state, first, second, and third detection resistance currents flow through the first, second, and third power supply lines 21, 22, and 23, respectively. At this time, the first, second, and third comparators 28, 29, and 30 detect the first, second, and third detection resistance currents flowing through the first, second, and third power supply lines 21, 22, and 23, respectively, so that The electronic control device 4 can detect whether the first, second, and third power supply lines 21, 22, and 23 are disconnected.

Then, the electronic control device 4 connects the first, second, and third detection resistors to the first, second, and third power supply lines 21, 22, and 23, respectively, by making the current detection current path 24 conductive by the disconnection detection switch 31. The time during which the current is flowing can be adjusted by switching the disconnection detection switch 31 from the on state to the off state. That is, the electronic control device 4 decreases the amount of power flowing through the first, second, and third power supply lines 21, 22, and 23, respectively, as the time period during which the disconnection detection switch 31 is continuously turned on is shortened. The detection resistor current can be reduced. Therefore, the electronic control device 4 can detect a disconnection without passing a large current.

The electronic control device 4 also includes a disconnection detection capacitor 32 installed downstream of the disconnection detection switch 31 in the current detection current path 24 . Thereby, the electronic control device 4 can suppress the first, second, and third detection resistor currents flowing through the current detection current path 24 to below the power storage capacity of the disconnection detection capacitor 32. Therefore, even if the disconnection detection switch 31 fails and the disconnection detection switch 31 cannot be switched from the on state to the off state, the electronic control device 4 is able to control the first, second, and third power supply lines. The first, second, and third detection resistor currents flowing through each of 21, 22, and 23 can be reduced. Therefore, the electronic control device 4 can detect a disconnection without passing a large current.

Further, the electronic control device 4 includes a pressure booster 19, a microcomputer 16, and a fuel injection drive IC 17. The booster 19 is supplied with the battery voltage Vb from the battery 5 via the first, second, and third power lines 21, 22, and 23, and is driven by being supplied with the battery voltage Vb. The microcomputer 16 and fuel injection drive IC 17 control the pressure booster 19 . The microcomputer 16 detects whether a disconnection has occurred in the first, second, and third power supply lines 21, 22, and 23 based on the detection results from the first, second, and third comparators 28, 29, and 30. The microcomputer 16 and the fuel injection drive IC 17 limit the current flowing to the booster 19 when detecting disconnection of the first, second, and third power supply lines 21, 22, and 23. Thereby, when detecting a wire breakage, the electronic control device 4 can suppress the amount of current flowing through the power supply line where the wire breakage has not occurred, thereby suppressing damage caused by heat generation inside the electronic control device 4.

The electronic control device 4 also includes a fuel injection drive IC 17 for driving the fuel injection device 3 that injects fuel into the engine, and a pressure booster 19. Thereby, even if the electronic control device 4 includes the fuel injection drive IC 17 and the booster 19 that require a large current to drive, it is possible to detect a disconnection without passing a large current.

In the embodiment described above, the battery 5 corresponds to an external power supply, the battery voltage Vb corresponds to a power supply voltage, and the first, second, and third power supply lines 21, 22, and 23 correspond to a plurality of power supply lines.
In addition, the first, second, and third detection resistor currents correspond to multiple power supply currents, and the first, second, and third current detection resistors 25, 26, and 27 and the first, second, and third comparators 28, 29, and 30 are currents. Corresponds to the detection section.

Further, the disconnection detection switch 31 corresponds to a detection switch, and the disconnection detection capacitor 32 corresponds to a detection capacitor.

Further, the booster 19 corresponds to a drive section, the microcomputer 16 and the fuel injection drive IC 17 correspond to a drive control section, and S10 to S40 correspond to processing as a disconnection detection section.
Further, the fuel injection drive IC 17 corresponds to a fuel injection drive circuit, the pressure booster 19 corresponds to a pressure boost circuit, and the engine corresponds to an internal combustion engine.

[Second embodiment]
A second embodiment of the present disclosure will be described below with reference to the drawings. Note that in the second embodiment, different parts from the first embodiment will be explained. Common configurations are given the same reference numerals.

The vehicle control system 1 of the second embodiment differs from the first embodiment in that the configuration of the detection unit 18 is changed and the boost execution process is changed.
The detection unit 18 of the second embodiment differs from the first embodiment in that, as shown in FIG. 4, a discharge path 50 and a discharge resistor 51 are added.

One end of the discharge path 50 is connected to a connection point between the disconnection detection switch 31 and the disconnection detection capacitor 32, and the other end is grounded. The discharge resistor 51 is installed on the discharge path 50. A discharge resistor 51 having a large constant is mounted so as not to inhibit the charging operation of the disconnection detection capacitor 32.

As shown in FIG. 5, the boost execution process of the second embodiment differs from the first embodiment in that the process of S110 is added and the process of S130 is added instead of S80.
That is, when a disconnection is detected in S40, the microcomputer 16 determines in S110 that the disconnection detected in S40 is a disconnection that occurred in the same current path as the current path detected in the disconnection detection in the previous boost execution process. Determine whether it exists or not.

Here, if the disconnection occurs in the same current path as the previous time, the microcomputer 16 moves to S60. On the other hand, if the disconnection does not occur in the same current path as last time, the microcomputer 16 moves to S50.

Further, when the boosting operation is completed in S70, the microcomputer 16 determines in S130 whether or not the vehicle starting state continues in the same manner as in S80. Here, if the vehicle starting state continues, the microcomputer 16 moves to S10. On the other hand, if the vehicle starting state is not continuing, the microcomputer 16 ends the boosting execution process.

FIG. 6 is a timing chart showing a boosting operation when a disconnection occurs in the first current path in the second embodiment.
As shown in FIG. 6, the vehicle activation signal is at a low level at time t0. The vehicle starts, and the vehicle start signal changes from low level to high level at time t1. As the vehicle activation signal changes to high level, the disconnection detection switch 31 is switched from the off state to the on state at time t2. Further, at time t3, the disconnection detection switch 31 is switched from the on state to the off state.

As a result, current flows in the second current path and the third current path between time t2 and time t3. As a result of current flowing through the second current path and the third current path, the capacitor charging voltage increases between time t2 and time t3.

Then, the microcomputer 16 determines whether the maximum values of the first, second, and third detection resistance current values between time t2 and time t3 are equal to or less than the first, second, and third disconnection judgment values J1, J2, and J3, respectively. to judge. Here, since the maximum value of the first detection resistor current value is less than or equal to the first disconnection determination value J1, the microcomputer 16 determines that a disconnection has occurred in the first current path.

Then, between time t3 and time t4, the microcomputer 16 calculates an appropriate engine speed and boost current value to suppress the boost current. As a result, the boosting operation is performed with the boosting current being suppressed between time t4 and time t5.

Furthermore, the disconnection detection switch 31 is switched from the on state to the off state at time t3, so that the capacitor charging voltage gradually decreases from time t3.
When the voltage boosting operation is completed at time t5, the disconnection detection switch 31 is switched from the off state to the on state at time t6. Further, at time t7, the disconnection detection switch 31 is switched from the on state to the off state.

When the boosted voltage is used at time t8, the boosting operation is performed again between time t9 and time t10 with the boosted current being suppressed in order to charge the reduced boosted voltage. The operations from time t4 to time 9 are repeatedly executed as long as the vehicle starting state continues.

The electronic control device 4 configured in this manner includes a discharge path 50 and a discharge resistor 51. The discharge path 50 branches from the current path 24 for current detection between the disconnection detection switch 31 and the disconnection detection capacitor 32. The discharge resistor 51 is provided on the discharge path 50. Thereby, the electronic control device 4 can discharge the charge stored in the disconnection detection capacitor 32 from the disconnection detection capacitor 32 via the discharge path 50 when detecting a disconnection. Therefore, the electronic control device 4 can repeatedly perform disconnection detection every time the charge stored in the disconnection detection capacitor 32 is released, and can improve the accuracy of disconnection detection.

[Third embodiment]
A third embodiment of the present disclosure will be described below with reference to the drawings. Note that in the third embodiment, parts different from the second embodiment will be explained. Common configurations are given the same reference numerals.

The vehicle control system 1 of the third embodiment differs from the second embodiment in that the configuration of the detection unit 18 is changed and the boost execution process is changed.
As shown in FIG. 7, the detection unit 18 of the third embodiment differs from the second embodiment in that a discharge switch 52 is added and a discharge resistor 53 is added instead of the discharge resistor 51. .

The discharge switch 52 is installed on the discharge path 50. The discharge switch 52 is switched between an on state and an off state according to a switch control signal from the microcomputer 16.

The discharge resistor 53 is installed downstream of the discharge switch 52 on the discharge path 50.
When releasing the charge charged in the disconnection detection capacitor 32, the disconnection detection switch 31 is turned off, and the discharge switch 52 is turned on.

When charging the disconnection detection capacitor 32, the disconnection detection switch 31 is in an on state, and the discharging switch 52 is in an off state. Therefore, the discharge resistor 53 does not affect the charging of the disconnection detection capacitor 32. Therefore, even if the discharge resistor 53 has a smaller resistance constant than the discharge resistor 51 of the second embodiment, it will not affect the charging operation, and it is possible to quickly release the charge charged in the disconnection detection capacitor 32. Become.

Next, the procedure of the boosting execution process according to the third embodiment will be explained.
When the boost execution process of the third embodiment is executed, the microcomputer 16 first stores 0 in the ON number C_on provided in the RAM in S210, as shown in FIG.

Then, in S220, the microcomputer 16 switches the disconnection detection switch 31 to the ON state and switches the discharge switch 52 to the OFF state.
Then, in S230, the microcomputer 16 repeatedly acquires the first, second, and third voltage detection signals from the first, second, and third comparators 28, 29, and 30 until the preset first switch-on time elapses. Then, the voltage values indicated by the first, second, and third voltage detection signals are stored in the RAM. Then, when the first switch-on time has elapsed, the microcomputer 16 ends the process of S230. Hereinafter, the period in which the first, second, and third voltage detection signals are repeatedly acquired in S230 will be referred to as a disconnection detection period.

When the process of S230 is completed, the microcomputer 16 switches the disconnection detection switch 31 to the OFF state and switches the discharge switch 52 to the ON state in S240. The microcomputer 16 then waits until the preset second switch-on time has elapsed, and when the second switch-on time has elapsed, ends the process of S240.

Next, the microcomputer 16 adds 1 to the value stored in the ON count C_on and stores the added value in the ON count C_on.
Then, the microcomputer 16 determines whether or not the value stored in the number of ON times C_on is greater than or equal to a preset number of times Je is the end of detection. In this embodiment, the number of detection ends Je is two.

Here, if the value stored in the on count C_on is less than the detection end count Je, the microcomputer 16 moves to S220. On the other hand, if the value stored in the on count C_on is equal to or greater than the detection end count Je, the microcomputer 16 switches the disconnection detection switch 31 to the off state and the discharge switch 52 to the off state in S270. Switch to

Next, in S280, the microcomputer 16 determines whether a disconnection has been detected based on the voltage value stored in the RAM. Specifically, the microcomputer 16 calculates the voltage values indicated by the first, second, and third voltage detection signals and the first, second, and third current detection resistors 25, 26 for each of the disconnection detection periods of the number of detection ends Je. , 27, the values of the first, second, and third detection resistor currents flowing through the first, second, and third current detection resistors 25, 26, and 27 within the disconnection detection period are calculated.

Then, the microcomputer 16 selects the first, second, and third disconnections in which the maximum values of the first, second, and third detection resistance current values within the disconnection detection period are respectively set in advance for each of the disconnection detection periods of the number of detection ends Je. It is determined whether or not it is less than or equal to the determination values J1, J2, and J3.

Specifically, the microcomputer 16 detects when the maximum value of the first detection resistance current value is equal to or less than the first disconnection judgment value J1 in at least one disconnection detection period among the disconnection detection periods of the number of times Je of detection ends. Then, it is determined that a disconnection has occurred in the first current path.

Further, the microcomputer 16 detects a second wire breakage when the maximum value of the second detection resistor current value is equal to or less than the second wire breakage determination value J2 in at least one wire breakage detection period of the number of wire breakage detection periods Je. It is determined that a disconnection has occurred in the current path.

In addition, the microcomputer 16 detects the third detection resistance current value when the maximum value of the third detection resistor current value is equal to or less than the third disconnection judgment value J3 in at least one disconnection detection period among the disconnection detection periods of the number of times Je of detection ends. It is determined that a disconnection has occurred in the current path.

Here, if a disconnection is not detected, the microcomputer 16 moves to S310. On the other hand, if a disconnection is detected, the microcomputer 16 determines in S290 whether the disconnection detected in S280 is a disconnection that occurred in the same current path as the current path detected in the disconnection detection in the previous boost execution process. Decide whether or not.

Here, if the disconnection occurs in the same current path as the previous time, the microcomputer 16 moves to S310. On the other hand, if the disconnection does not occur in the same current path as the previous time, the microcomputer 16 in S300 sets an appropriate engine speed and boost voltage in order to suppress the boost current flowing to the boost unit 19 in the same way as in S50. Calculate the current value. Further, in S300, the microcomputer 16 outputs an engine speed control signal to the engine speed control device 2 and a fuel injection control signal to the fuel injection drive IC 17 in the same manner as S50. When the process of S300 is finished, the microcomputer 16 moves to S310.

When the process moves to S310, the microcomputer 16 causes the fuel injection drive IC 17 to start the pressure increasing operation by the pressure boosting section 19 in the same manner as in S60. Then, in S320, the microcomputer 16 determines whether or not the boosting operation by the boosting section 19 has been completed, in the same manner as in S70.

Here, if the boosting operation is not completed, the microcomputer 16 repeats the process of S320 and waits until the boosting operation is completed. When the boosting operation is completed, the microcomputer 16 determines in S330 whether or not the vehicle starting state continues in the same manner as in S80.

Here, if the vehicle starting state continues, the microcomputer 16 moves to S210. On the other hand, if the vehicle starting state is not continuing, the microcomputer 16 ends the boosting execution process.

FIG. 9 is a timing chart showing a boosting operation when a disconnection occurs in the first current path in the third embodiment.
As shown in FIG. 9, the vehicle activation signal is at a low level at time t0. The vehicle starts, and the vehicle start signal changes from low level to high level at time t1. As the vehicle activation signal changes to high level, the disconnection detection switch 31 is switched from the off state to the on state at time t2. Further, at time t3, the disconnection detection switch 31 is switched from the on state to the off state.

As a result, current flows in the second current path and the third current path between time t2 and time t3. As a result of current flowing through the second current path and the third current path, the capacitor charging voltage increases between time t2 and time t3.

Further, at time t3, the disconnection detection switch 31 is switched from the on state to the off state, and the discharge switch 52 is switched from the off state to the on state. As a result, the capacitor charging voltage decreases from time t3.

Furthermore, at time t4, the disconnection detection switch 31 is switched from the off state to the on state, and the discharge switch 52 is switched from the on state to the off state. As a result, the capacitor charging voltage increases between time t4 and time t5.

Further, at time t5, the disconnection detection switch 31 is switched from the on state to the off state, and the discharge switch 52 is switched from the off state to the on state. As a result, the capacitor charging voltage decreases from time t5. Furthermore, at time t6, the discharge switch 52 is switched from the on state to the off state.

Then, the microcomputer 16 determines whether the maximum values of the first, second, and third detection resistance current values between time t2 and time t3 are equal to or less than the first, second, and third disconnection judgment values J1, J2, and J3, respectively. to judge. Furthermore, the microcomputer 16 determines whether the maximum values of the first, second, and third detection resistance current values between time t4 and time t5 are equal to or less than the first, second, and third disconnection determination values J1, J2, and J3, respectively. to judge.

Here, since the maximum value of the first detection resistor current value is equal to or less than the first disconnection judgment value J1 at least between the time t2 and the time t3 and the time t4 and the time t5, the microcomputer 16 determines that a disconnection has occurred in the first current path.

Then, between time t6 and time t7, the microcomputer 16 calculates an appropriate engine speed and boost current value to suppress the boost current. As a result, the boost operation is performed with the boost current suppressed between time t7 and time t8.

When the boost operation is completed at time t8, the disconnection detection switch 31 and the discharge switch 52 are switched between the on state and the off state between time t9 and time t10 in the same way as from time t2 to time t6. Repeat the switching action twice.

When the boosted voltage is used at time t11, the boosting operation is performed again between time t12 and time t13 with the boosted current being suppressed in order to charge the reduced boosted voltage. The operations from time t7 to time 12 are repeatedly executed as long as the vehicle starting state continues.

The electronic control device 4 configured in this manner includes a discharge switch 52 that is installed upstream of the discharge resistor 53 in the discharge path 50 and switches the discharge path 50 between a conductive state and a cutoff state. Thereby, the electronic control device 4 switches the discharge path 50 from the cutoff state to the conduction state with the discharge switch 52, so that the electric charge stored in the disconnection detection capacitor 32 is transferred to the discharge path 50 when detecting a disconnection. It can be discharged from the disconnection detection capacitor 32 via the disconnection detection capacitor 32. Therefore, the electronic control device 4 can repeatedly perform disconnection detection every time the charge stored in the disconnection detection capacitor 32 is released, and can improve the accuracy of disconnection detection.

Furthermore, by switching the discharge path 50 from the cutoff state to the conduction state with the discharge switch 52, the charge stored in the disconnection detection capacitor 32 is released, so that the resistance value of the discharge resistor 53 is changed from the disconnection detection capacitor 32. There is no need to increase the size to the extent that it does not impede the storage of electricity. Therefore, the electronic control device 4 can suppress the discharge resistance 53 from inhibiting the discharge of charge via the discharge path 50, and shorten the time required for discharge of the charge from the disconnection detection capacitor 32. .

In the embodiment described above, S210 to S280 correspond to processing by the disconnection detection section.
Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and can be implemented with various modifications.

[Modification 1]
For example, in the embodiment described above, a mode is shown in which one current path 24 for current detection is provided, but a plurality of current paths 24 for current detection may be provided. For example, in each of the first, second, and third power supply lines 21, 22, and 23, there are three different current detection current paths 24 installed downstream of the first, second, and third current detection resistors 25, 26, and 27. may be provided. In this case, three disconnection detection switches 31 and three disconnection detection capacitors 32 corresponding to each of the three current detection current paths 24 are provided.

Further, three discharge paths 50 and three discharge resistors 51 corresponding to each of the three current detection current paths 24 may be provided.
Moreover, you may make it provide three discharge paths 50, three discharge switches 52, and three discharge resistors 53 corresponding to each of the three current paths 24 for current detection.

The microcomputer 16 and techniques described in this disclosure utilize a special purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. May be realized. Alternatively, the microcomputer 16 and techniques described in this disclosure may be implemented by a special purpose computer provided by configuring the processor with one or more special purpose hardware logic circuits. Alternatively, the microcomputer 16 and techniques described in this disclosure may include a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. It may be realized by one or more dedicated computers configured with. The computer program may also be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. The method of realizing the functions of each part included in the microcomputer 16 does not necessarily need to include software, and all the functions may be realized using one or more pieces of hardware.

A plurality of functions of one component in the above embodiment may be realized by a plurality of components, and a function of one component may be realized by a plurality of components. Further, a plurality of functions possessed by a plurality of constituent elements may be realized by one constituent element, or one function realized by a plurality of constituent elements may be realized by one constituent element. Further, a part of the configuration of the above embodiment may be omitted. Further, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of other embodiments.

In addition to the above-mentioned electronic control device 4, a system including the electronic control device 4 as a component, a program for making a computer function as the electronic control device 4, and a non-transitional physical record such as a semiconductor memory in which this program is recorded. The present disclosure can also be implemented in various forms such as media and disconnection detection methods.

4... Electronic control device, 5... Battery, 16... Microcomputer, 21... First power line, 22... Second power line, 23... Third power line, 24... Current path for current detection, 25... First current detection Resistor, 26... Second current detection resistor, 27... Third current detection resistor, 28... First comparator, 29... Second comparator, 30... Third comparator, 31... Disconnection detection switch

Claims (8)

An electronic control device (4) that controls a vehicle by being supplied with power supply voltage from an external power source (5),
a plurality of power supply lines (21, 22, 23) connected to the external power supply and supplying the power supply voltage from the external power supply;
a current detection unit (25, 26, 27, 28, 29, 30) configured to detect a plurality of power supply currents flowing in each of the plurality of power supply lines;
a current detection current path (24) installed between a location downstream of the current detection section and ground, through which the power supply current flows;
An electronic control device comprising: a detection switch (31) that switches the current detection current path between a conduction state and a cutoff state. The electronic control device according to claim 1,
An electronic control device including a detection capacitor (32) installed downstream of the detection switch in the current detection current path. The electronic control device according to claim 2,
a discharge path (50) branching from the current detection current path between the detection switch and the detection capacitor;
An electronic control device comprising: a discharge resistor (51, 53) provided on the discharge path. The electronic control device according to claim 3,
An electronic control device including a discharge switch (52) that is installed upstream of the discharge resistor in the discharge path and switches the discharge path between a conductive state and a cutoff state. The electronic control device according to any one of claims 1 to 4,
The electronic control device has one current path for current detection. The electronic control device according to any one of claims 1 to 5,
The detection switch is an electronic control device controlled by a microcomputer to which a detection signal from the current detection section is input. The electronic control device according to any one of claims 1 to 6,
a drive unit (19) configured to be supplied with the power supply voltage from the external power supply via the plurality of power supply lines and to be driven by the supply of the power supply voltage;
a drive control section (16, 17) configured to control the drive section;
A disconnection detection unit (S10 to S40, S210 to S280) configured to detect whether or not a disconnection has occurred in at least one of the plurality of power supply lines based on a detection result by the current detection unit. Prepare,
The drive control unit is an electronic control device that limits the current flowing to the drive unit when the disconnection detection unit detects the disconnection. The electronic control device according to any one of claims 1 to 6,
An electronic control device that includes at least one of a fuel injection drive circuit (17) for driving a fuel injection device that injects fuel into an internal combustion engine, and a booster circuit (19).

Images