JP6036048B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device.

  Conventionally, in a vehicle control device capable of automatically stopping and restarting an engine, a main battery electrically coupled to a starter, a sub battery electrically coupled to an electric load of the vehicle, a main battery and a sub battery There is known a technology that includes a relay that can be switched on / off by whether or not the battery is electrically coupled, and operates the starter by turning off the relay when restarting after automatic engine stop ( Patent Document 1). Thereby, it is possible to prevent the voltage drop (instantaneous drop) of the sub-battery from occurring when the starter is operated, and it is possible to prevent a shortage of power supply to the electric load. Further, the main battery and the sub battery can be charged by the alternator driven by the engine with the relay turned on.

JP 2008-82275 A

  However, in the vehicle control apparatus described above, the following problem occurs when an off-fixing failure occurs in which the relay between the main battery and the sub-battery continues to be turned off. In other words, if a relay off-fixing failure occurs when a command to turn on the relay is issued and the alternator tries to charge the main battery and the sub battery, the sub battery cannot be charged. The voltage decreases, and there is a possibility that insufficient power supply from the sub-battery to the electric load occurs.

  An object of the present invention is to detect an off-fixation failure of a relay between a main battery and a sub battery.

A vehicle control apparatus according to the present invention includes a motor generator mechanically coupled to an output shaft of an engine, a first battery electrically coupled to the motor generator, and a first battery electrically coupled to an electric load of the vehicle. 2 battery, a relay that can switch whether to electrically couple the first battery and the second battery by ON / OFF of its own, and the relay is turned off during the power running operation of the motor generator, and the regenerative operation of the motor generator A relay control means for turning on the relay is provided. In this vehicle control device, the relay is fixed off when the difference between the voltage of the first battery and the voltage of the second battery becomes larger than a predetermined voltage in a state where a command to turn on the relay is issued. Relay failure diagnosis means for determining that the The relay failure diagnosing means is in a state in which a command to turn on the relay is issued and a difference between the voltage of the first battery and the voltage of the second battery is larger than a second predetermined voltage higher than the first predetermined voltage. When a second predetermined time shorter than the first predetermined time elapses, it is determined that the relay is fixed off. The first predetermined voltage is higher than the maximum voltage difference between the first battery and the second battery that occurs in a steady state in which a steady current flows. The second predetermined voltage is higher than the maximum voltage difference between the first battery and the second battery that occurs when a transient current flows between the first battery and the second battery.

  According to the present invention, the difference between the voltage of the first battery and the voltage of the second battery is larger than the predetermined voltage while the motor generator is in the regenerative operation and the command to turn on the relay is issued. In this case, since it is determined that the relay is stuck off, a relay off stuck failure can be detected with high accuracy.

FIG. 1 is a schematic configuration diagram of a vehicle control device according to an embodiment. FIG. 2 is a control system diagram of the gasoline engine. FIG. 3 is a detailed circuit configuration diagram including a main battery, a sub battery, a relay box including a relay, and an engine control module. FIG. 4 is another example of a detailed circuit configuration diagram including a main battery, a sub battery, a relay box including a relay, and an engine control module. FIG. 5 is a diagram illustrating timing for diagnosing a relay-off stuck failure. FIG. 6 is a flowchart illustrating a flow of a relay-off-fixation failure diagnosis process performed by the vehicle control device according to the embodiment.

  FIG. 1 is a schematic configuration diagram of a vehicle control device according to an embodiment. In FIG. 1, a vehicle 1 is provided with an engine 2, a motor generator 21, and an air conditioner compressor 31. Specifically, the output shaft 3 of the engine 2, the rotating shaft 22 of the motor generator 21, and the rotating shaft 32 of the air conditioner compressor 31 are arranged in parallel, and the crank pulley 4 is connected to the rotating shafts 22 and 32 at one end of the output shaft 3. The pulleys 23 and 33 are attached to each other. A belt 5 is wound around each of the three pulleys 4, 23, and 33, and power is transmitted (conducted) between the output shaft 3 and the rotary shafts 23 and 33 of the engine 2 by the belt 5.

  The starter 6 is used for starting the engine 2. A torque converter 8 and a belt type automatic transmission 9 are connected to the other end of the output shaft 3 of the engine 2. The torque converter 8 has a pump impeller and a turbine runner (not shown). The belt-type automatic transmission 9 includes a primary pulley and a secondary pulley (not shown) and a steel belt that is wound around these pulleys. The rotational driving force of the engine 2 is finally transmitted to vehicle drive wheels (not shown) via the torque converter 8 and the automatic transmission 9.

  As a power source for the vehicle 1, a main battery 41 and a sub battery 42 are provided. Both are 14V batteries. Two relays 43a and 43b arranged in parallel are connected between the two batteries 41 and. The reason why the two relays 43a and 43b are provided is for backup when one of the relays breaks down, and also for extending the number of durable operation times of the relay as compared with the case where only one relay is provided. .

  The starter 6 and the motor generator 21 are connected between the main battery 41 and the relays 43 a and 43 b, and power is supplied from the main battery 41. Since motor generator 21 is composed of an AC machine, inverter 24 for converting DC from main battery 41 to AC is attached.

  The electric load 44 is a load that does not affect its own operation even when a voltage sag in which the voltage of the battery instantaneously drops occurs, and power is supplied from the main battery 41. On the other hand, the electrical load 45 is a load that affects its own operation when an instantaneous drop occurs, and power is supplied from the sub-battery 42.

  The engine control module (ECM) 51 controls the engine 2, the starter 6, the motor generator 21, and the relays 43a and 43b. For example, the engine control module 51 turns off the relays 43 a and 43 b during the power running operation of the motor generator 21 to disconnect the electrical connection between the main battery 41 and the sub battery 42, and the relay 43 a or 43 b during the regenerative operation of the motor generator 21. The main battery 41 and the sub-battery 42 are electrically coupled by turning on 43b. Further, the engine control module 51 diagnoses whether an off-fixing failure of the relays 43a and 43b has occurred by a method described later.

  FIG. 2 is a control system diagram of a gasoline engine. Each intake port (not shown) is provided with a fuel injection valve 7. The fuel injection valve 7 supplies fuel to the engine 2 intermittently.

  The intake passage 11 is provided with an electronically controlled throttle valve 12, and an opening degree of the throttle valve 12 (hereinafter referred to as “throttle opening degree”) is controlled by a throttle motor 13. The actual throttle opening is detected by the throttle sensor 14 and input to the engine control module 51.

  The engine control module 51 receives an accelerator opening signal (amount of depression of the accelerator pedal 52) from the accelerator sensor 53, a crank angle signal from the crank angle sensor 54, and an intake air amount signal from the air flow meter 55. The From the signal of the crank angle sensor 54, the rotational speed of the engine 2 is calculated. The engine control module 51 calculates the target intake air amount and the target fuel injection amount based on these signals, and the throttle motor 13 and each fuel injection valve 7 so as to obtain the target intake air amount and the target fuel injection amount. Command.

  Here, the control of the intake air amount will be outlined (refer to Japanese Patent Laid-Open No. 9-287513). By searching a predetermined map from the accelerator opening APO and the engine speed Ne, the target basic intake air amount and the target equivalent ratio tDML are respectively calculated. A value obtained by dividing the target basic intake air amount by the target equivalent ratio tDML is set as the target intake air amount. The target throttle valve opening is obtained by searching a predetermined map from the target intake air amount and the engine speed. The target throttle valve opening is converted into a command value and output to the throttle motor 13.

Next, control of fuel injection (fuel injection amount and fuel injection timing) will be outlined. The output of the air flow meter 55 is A / D converted and linearized to calculate the intake air amount Qa. From this intake air amount Qa and the engine speed Ne, the basic injection pulse width Tp0 [ms] that provides an air-fuel mixture with a substantially stoichiometric air-fuel ratio (equivalent ratio = 1.0) is expressed as Tp0 = K × Qa / Ne (where K is determined as a constant). next,
Tp = Tp0 × Fload + Tp−1 × (1−Fload)
Where Fload: weighted average coefficient,
Tp-1: Previous Tp,
The cylinder air amount equivalent pulse width Tp [ms] is obtained by the following equation. This is because the air amount flowing into the cylinder (combustion chamber) (that is, the cylinder air amount) has a response delay with respect to the intake air amount in the air flow meter section, and this response delay is approximated by a primary delay. The weighted average coefficient Fload [nameless number] which is a coefficient of the first order lag is obtained by searching a predetermined map from the product Ne · V of the rotational speed Ne and the cylinder volume V and the total flow path area Aa of the intake pipe. Based on the cylinder air amount equivalent pulse width Tp thus determined, the fuel injection pulse width Ti [ms] given to the fuel injection valve 7 is
Ti = Tp × tDML × (α + αm−1) × 2 + Ts
However, tDML: target equivalent ratio [anonymous number],
α: Air-fuel ratio feedback correction coefficient [anonymous number]
αm: Air-fuel ratio learning value [anonymous number]
Ts: Invalid injection pulse width [anonymous number],
It is calculated by the following formula. When the predetermined fuel injection timing comes, the fuel injection valve 7 is opened for the period of this fuel injection pulse width Ti.

  The gasoline engine 2 includes a spark plug facing the combustion chamber (cylinder). The engine control module 51 generates a spark in the spark plug by cutting off the primary current of the ignition coil at a predetermined time before the compression top dead center, thereby igniting the air-fuel mixture in the combustion chamber.

  When the engine control module 51 determines that there is an initial start request based on a signal from the starter switch 56, the engine control module 51 drives the starter 6 to start the engine 2.

  The engine control module 51 performs idle stop control for the purpose of improving fuel consumption. That is, when the accelerator pedal 52 is not depressed (APO = 0), the brake pedal 57 is depressed (the brake switch 58 is ON), and the vehicle 1 is in a stopped state (vehicle speed VSP = 0), the idle stop is performed. The permission condition is satisfied. When the idle stop permission condition is satisfied, the fuel injection from the fuel injection valve 7 to the intake port is shut off, and the engine 2 is stopped. Thereby, useless fuel consumption is reduced.

  Thereafter, when the accelerator pedal 52 is depressed or the brake pedal 57 is returned (the brake switch 58 is OFF) in the idle stop state, the idle stop permission condition is not satisfied. If the idle stop permission condition is not satisfied, the engine 2 is cranked using the motor generator 21 as a starter, the fuel injection from the fuel injection valve 7 and the spark ignition by the spark plug are restarted, and the engine 2 is restarted. .

  Thus, by using the motor generator 21 exclusively for engine restart from idle stop, the use frequency of the starter 6 is reduced and the starter 6 is protected. When the starter 6 and the motor generator 21 are driven, the engine control module 51 cuts off both the two relays 43a and 43b to electrically disconnect the main battery 41 and the sub-battery 42. This prevents the voltage of the sub-battery 42 from fluctuating with the starting operation of the engine 2.

  Returning to FIG. 1, the description will be continued. The vehicle 1 is provided with an automatic transmission control unit (CVTCU) 61. The automatic transmission control unit 61 controls the gear ratio of the automatic transmission 9 in a stepless manner according to the vehicle running conditions determined from the vehicle speed and the throttle opening. The torque converter 8 having a pump impeller and a turbine runner is provided with a mechanical lockup clutch for fastening and releasing the pump impeller and the turbine runner. The travel range of the vehicle that engages the lockup clutch is predetermined as a lockup region (vehicle speed and throttle opening are used as parameters). The automatic transmission control unit 61 engages the lock-up clutch to directly connect the engine 2 and the transmission 9 when the vehicle driving condition is in the lock-up region, and the vehicle driving condition is not in the lock-up region. Sometimes the lockup clutch is released. When the engine 2 and the transmission 9 are in a directly connected state, the torque converter 8 does not absorb the torque, and the fuel efficiency is improved accordingly.

  The vehicle 1 also includes a vehicle dynamics control unit (VDCCU) 62, a vehicle speed sensitive electric power steering control unit (EPSCU) 63, an air conditioner auto amplifier 64, and a combination meter 66. Is provided. When the vehicle dynamic control unit 62 is about to cause a side slip or a tail swing of the vehicle, the sensor detects a side slip state, and improves vehicle stability during traveling by brake control and engine output control. The vehicle speed sensitive electric power steering control unit 63 outputs an optimum assist torque signal to the EPS motor from the steering torque input from the torque sensor and the vehicle speed.

  The automatic transmission control unit 61, the vehicle dynamic control unit 62, the vehicle speed sensitive power steering control unit 63, and the combination meter 66 are electric loads that cannot tolerate a voltage drop. Therefore, these are supplied with power from the sub-battery 42.

  The engine control module 51 and each of the three control units 61 to 63, an air conditioner auto amplifier (A / C Amp) 64, and a combination meter 66 are connected by a CAN (Controller Area Network). A vehicle speed signal is input from the combination meter 66 to the engine control module 51.

  The motor generator 21 is used not only for engine restart from idle stop but also for torque assist during vehicle travel. When permitting torque assist, the main battery 41 is used as a power source so that the engine 2 is torque-assisted, and a predetermined assist torque is generated in the motor generator 21. When torque assist is prohibited, no assist torque is generated. As a result, after the engine 2 is started and the vehicle 1 starts to travel, good acceleration response (driability) is obtained.

  The inverter 24 and the engine control module 51 are connected by a LIN (Local Internet Network). Via the LIN, the engine control module 51 instructs the inverter 24 whether to drive the motor generator 21 or to generate electric power with the motor generator 21 or how much current to flow to drive the motor.

  FIG. 3 is a detailed circuit configuration diagram including the main battery 41, the sub battery 42, the relay box 43 including the relays 43 a and 43 b, and the engine control module 51. Based on the voltage difference between the voltage of the main battery 41 and the voltage of the sub battery 42, the engine control module 51 detects an off-fixation failure in which the relays 43a and 43b are kept off.

  The engine control module 51 calculates the voltage of the main battery based on the charge / discharge current of the main battery 41 detected by the current sensor 71 and the predicted values of the harness and the internal resistance of the main battery 41. Further, the voltage of the sub battery 42 is calculated based on the charge / discharge current of the sub battery 42 detected by the current sensor 72 and the predicted value of the harness and the internal resistance of the sub battery 42.

  The engine control module 51 alternately turns on one of the relays 43a and 43b when the relays 43a and 43b are normally turned on and when the relays 43a and 43b are turned on normally. . More specifically, both of the relays 43a and 43b are turned off during the power running operation of the motor generator 21, and one of the relays 43a and 43b is turned on during the regenerative operation of the motor generator 21. As a result, the relays 43a and 43b can be evenly consumed, and the number of durability operations can be increased as compared with the case where only one relay is provided.

  FIG. 4 is another example of a detailed circuit configuration diagram including a main battery 41, a sub battery 42, a relay box 43 including relays 43a and 43b, and an engine control module 51. The difference from the circuit configuration diagram shown in FIG. 3 is the position where the current sensors 71 and 72 are provided.

  FIG. 5 is a diagram illustrating timing for diagnosing a relay-off stuck failure. In FIG. 5, the vehicle speed V, the state of the engine 2, the states of the relays 43a and 43b, and the state of the relay-off fixing diagnosis are shown in order from the top. As shown in FIG. 5, when a command to turn on either one of the relays 43a and 43b is issued, such as when the engine 2 is stopped after the initial start, when the vehicle is accelerated or decelerated, or after restarting from an idle stop. Execute relay off adhesion diagnosis.

  As described above, during the regenerative operation of the motor generator 21, either one of the relays 43a and 43b is turned on to charge the main battery 41 and the sub battery 42 by supplying a charging current. At this time, if an off-fixing failure has occurred in the relay that has been issued the ON command, the sub battery 42 cannot be charged, and only the sub battery 42 is discharged, and the voltage continues to decrease. The voltage difference between the main battery 41 and the sub battery 42 that continues to discharge is widened.

  Therefore, in this embodiment, when the voltage difference between the main battery 41 and the sub-battery 42 becomes larger than a predetermined voltage, it is determined that an off-fixing failure has occurred in the relay to which the on command is issued. More specifically, when a later-described first condition or second condition is satisfied, it is determined that a relay-off stuck failure has occurred.

The case where the first condition is satisfied is a case where all of the following conditions (a) to (c) are satisfied.
(A) A command is issued to turn on one of the relays 43a and 43b.
(B) The ignition switch is turned on.
(C) The voltage difference between the main battery 41 and the sub-battery 42 is not less than a first predetermined voltage (for example, 1.04 V) and the discharge current is flowing from the sub-battery 42 for a first predetermined time (for example, , 25.5 sec) elapsed

  The first predetermined voltage is determined in advance based on a maximum voltage difference V1 between the batteries that is theoretically generated in a steady state in which a steady current flows between the main battery 41 and the sub-battery 42. More specifically, the first predetermined voltage is set to a value higher than the maximum voltage difference V1. The maximum voltage difference V1 between the batteries that is theoretically generated in a steady state where a steady current flows is expressed by the following equation (1). However, the harness resistance value in the expression (1) is the resistance value of the harness between the main battery 41 and the sub battery 42. Further, the battery voltage calculation error of the engine control module 51 includes current detection errors of the current sensors 71 and 72.

  Maximum voltage difference V1 = voltage drop in relays 43a and 43b + (harness resistance value × maximum value of steady energization current) + battery voltage calculation error of engine control module 51 (1)

  When a command to turn on one of the relays 43a and 43b is issued in a steady state where a steady current is flowing, the voltage difference between the main battery 41 and the sub battery 42 is turned on if the relay to which the command is issued is turned on. Does not exceed the aforementioned maximum voltage difference V1. That is, if the voltage difference between the main battery 41 and the sub-battery 42 is equal to or greater than the first predetermined voltage, it can be determined that a relay-off stuck failure has occurred, but the voltage difference between the batteries is equal to or greater than the first predetermined voltage. In order to determine that the relay-off fixing failure has occurred in a state where the occurrence of the failure is stable, the first predetermined time as the determination time is a relatively long time (for example, the maximum value that can be set by the engine control module 51). Set.

  On the other hand, the case where the second condition is satisfied is a case where all of the above conditions (a), (b) and the following (d) are satisfied.

  (D) In a state where the voltage difference between the main battery 41 and the sub-battery 42 is equal to or higher than a second predetermined voltage (eg, 1.44 V) higher than the first predetermined voltage, and a discharge current is flowing from the sub-battery 42, Elapsed second predetermined time (for example, 100 msec) shorter than the first predetermined time

  The second predetermined voltage is determined in advance based on the maximum voltage difference V2 between the batteries that is theoretically generated in a state where a transient current flows between the main battery 41 and the sub battery 42. More specifically, the second predetermined voltage is set to a value higher than the maximum voltage difference V2. The maximum voltage difference V2 between the batteries that is theoretically generated in a state where the transient current flows is expressed by the following equation (2).

  Maximum voltage difference V2 = voltage drop in relays 43a and 43b + (harness resistance value × maximum value of transient energization current) + battery voltage calculation error of engine control module 51 (2)

  When the voltage difference between the main battery 41 and the sub-battery 42 is equal to or higher than the second predetermined voltage higher than the first predetermined voltage, it is necessary to quickly determine that a relay-off failure has occurred. The time is set to a value that is as short as possible and does not cause a false diagnosis due to a small voltage fluctuation such as noise.

  FIG. 6 is a flowchart illustrating a flow of a relay-off-fixation failure diagnosis process performed by the vehicle control device according to the embodiment. When the ignition switch is turned on, the engine control module 51 starts the process of step S10 at a predetermined cycle.

  In step S10, it is determined whether or not a command to turn on one of the relays 43a and 43b is issued. If it is determined that a command to turn on one of the relays 43a and 43b has been issued, the process proceeds to step S20.

  In step S20, a voltage difference between the main battery 41 and the sub battery 42 is calculated.

  In step S30, it is determined whether or not the voltage difference calculated in step S20 is greater than or equal to a second predetermined voltage and whether or not a discharge current is flowing from the sub-battery 42. If it is determined that the battery voltage difference is equal to or greater than the second predetermined voltage and a discharge current is flowing from the sub-battery 42, the process proceeds to step S40. Otherwise, the process proceeds to step S60.

  In step S40, 1 is added to the counter Ta. The initial value of the counter Ta is 0.

  In step S50, it is determined whether the counter Ta is greater than a predetermined threshold value Th2. The predetermined threshold value Th2 is set in advance as a value for determining whether or not the second predetermined time has elapsed since the determination in step S30 was affirmed. If it is determined that the counter Ta is equal to or smaller than the predetermined threshold value Th2, the process returns to step S20. If it is determined that the counter Ta is greater than the predetermined threshold value Th2 (second predetermined time has elapsed), the process proceeds to step S90.

  In step S60, it is determined whether or not the voltage difference calculated in step S20 is greater than or equal to the first predetermined voltage and whether or not a discharge current is flowing from the sub-battery 42. If it is determined that the battery voltage difference is equal to or greater than the first predetermined voltage and the discharge current is flowing from the sub-battery 42, the process proceeds to step S70. Otherwise, the process of the flowchart is terminated.

  In step S70, 1 is added to the counter Tb. Note that the initial value of the counter Tb is 0.

  In step S80, it is determined whether or not the counter Tb is greater than a predetermined threshold value Th1. The predetermined threshold value Th1 is set in advance to determine whether or not the first predetermined time has elapsed since the determination in step S60 was affirmed. If it is determined that the counter Tb is equal to or smaller than the predetermined threshold value Th1, the process returns to step S20. If it is determined that the counter Tb is greater than the predetermined threshold value Th1, the process proceeds to step S90.

  In step S90, it is determined that an off-fixing failure has occurred in the relay for which the on command has been issued.

  As described above, according to the vehicle control apparatus in the embodiment, the motor generator 21 mechanically coupled to the output shaft of the engine, the main battery 41 electrically coupled to the motor generator 21, and the electric load of the vehicle And a sub-battery 42 electrically coupled to the main battery 41 and relays 43a and 43b capable of switching whether or not the main battery 41 and the sub-battery 42 are electrically coupled to each other. During the power running operation, the relays 43a and 43b are turned off, and during the regenerative operation of the motor generator 21, the relay 43a or 43b is controlled to be turned on. A command to turn on is issued when the difference between the voltage and the voltage of the sub-battery 42 is greater than a predetermined voltage. It determines that the relay is stuck off. During regenerative operation of the motor generator 21, if either one of the relays 43a and 43b is on, charging current is supplied to the main battery 41 and the sub-battery 42 to perform charging, but an on command is issued. If an off-fixing failure occurs in the relay, the sub-battery 42 cannot be charged, only the sub-battery 42 is discharged and the voltage continues to decrease, and the voltage difference between the main battery 41 and the sub-battery 42 Spread. Therefore, when the command to turn on the relay 43a or 43b is issued, if the difference between the voltage of the main battery 41 and the voltage of the sub-battery 42 is greater than a predetermined voltage, it is certain that a relay-off stuck failure has occurred. Can be detected.

  In particular, when a command to turn on the relay is issued and the difference between the voltage of the main battery 41 and the voltage of the sub-battery 42 is larger than the first predetermined voltage and the first predetermined time elapses, the relay turns on. It is determined that the relay for which the command to issue is issued is stuck off. As a result, it is possible to accurately detect an off-fixation failure of the relay.

  In addition, in a state where a command to turn on the relay is issued, the first predetermined voltage in a state where the difference between the voltage of the main battery 41 and the voltage of the sub battery 42 is larger than the second predetermined voltage higher than the first predetermined voltage. When a second predetermined time shorter than the time has elapsed, it is determined that the relay that has been instructed to turn on is stuck off. As a result, it is possible to quickly detect an off-fixation failure of the relay.

  The present invention is not limited to the above-described embodiment, and various modifications and applications are possible without departing from the gist of the present invention. For example, the voltages of the main battery 41 and the sub-battery 42 are calculated from the charge / discharge current of the battery and the predicted value of the internal resistance of the battery, but may be directly detected by providing a voltage sensor.

2 ... Engine 21 ... Motor generator 41 ... Main battery (first battery)
42 ... Sub battery (second battery)
43a, 43b ... relay 51 ... engine control module (relay control means, relay failure diagnosis means)

Claims (2)

A motor generator mechanically coupled to the output shaft of the engine;
A first battery electrically coupled to the motor generator;
A second battery electrically coupled to an electrical load of the vehicle;
A relay capable of switching whether or not to electrically couple the first battery and the second battery by ON / OFF of the first battery and the second battery;
During the power running operation of the motor generator, the relay is turned off to disconnect the electrical connection between the first battery and the second battery, and during the regenerative operation of the motor generator, the relay is turned on to turn the first battery and Relay control means for electrically coupling the second battery;
When the command to turn on the relay is issued and the difference between the voltage of the first battery and the voltage of the second battery is greater than a predetermined voltage, it is determined that the relay is fixed off. Relay failure diagnosis means to
Equipped with a,
The relay failure diagnosing means is configured to output a second predetermined voltage in which a difference between the voltage of the first battery and the voltage of the second battery is higher than the first predetermined voltage in a state where a command to turn on the relay is issued. When a second predetermined time shorter than the first predetermined time elapses in a state larger than the voltage, it is determined that the relay is fixed off,
The first predetermined voltage is higher than a maximum voltage difference between the first battery and the second battery that occurs in a steady state in which a steady current flows.
The second predetermined voltage is higher than a maximum voltage difference between the first battery and the second battery that occurs in a state where a transient current flows between the first battery and the second battery. A control device for a vehicle. The vehicle control device according to claim 1,
The relay failure diagnosing means is in a state where a command to turn on the relay is issued, and a difference between the voltage of the first battery and the voltage of the second battery is greater than a first predetermined voltage. When a predetermined time has elapsed, it is determined that the relay is fixed off,
A control apparatus for a vehicle.

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