JP2015124655A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control device which can determine that an abnormality occurs in the transition of a power supply state when performing idling stop control.SOLUTION: In an ECU 20 employed to a vehicle in which a power supply state of a battery 11 is transited between an on-state that an engine 21 is brought into an operable state and a non on-state that the engine is not in the on-state on the basis of a state transition pattern which is defined according to a state of a vehicle when an operation signal of a power supply switch 12 is outputted, the ECU automatically stops the engine 21 by the establishment of a prescribed automatic stop condition when the power supply state is in the on-state, performs idling stop control for automatically restarting the engine 21 by the establishment of a prescribed automatic restart condition, and determines that a transition abnormality of the power supply state occurs when the power supply state is transited to a state that the power supply state is not regulated by the state transition pattern in a state that the engine 21 is automatically stopped.

Description

  The present invention relates to an engine control device that is applied to a vehicle that performs idling stop control for automatically stopping and restarting an engine.

  A push type (push button type) ignition switch that switches the power supply state from the battery by a driver's pressing operation has appeared. In the case of a push-type switch, the power supply state transitions depending on the condition when the switch is pressed, that is, whether the position of the shift lever or the brake pedal is depressed.

  That is, the power supply state is an off state in which power is not supplied to the accessory device and the engine, an accessory state in which power is supplied only to the accessory device, an on state in which power is supplied to the accessory device and the engine, and power is supplied to the starter motor and the engine. Is switched to an engine start state for starting the engine.

  Also, an engine control device that performs idling stop control when a predetermined automatic stop condition is satisfied is known in order to reduce fuel consumption and exhaust emissions. For example, in Patent Document 1, when the power supply state is on, the engine is automatically stopped when a predetermined automatic stop condition is satisfied, and the engine is automatically restarted when a predetermined automatic restart condition is satisfied. An engine control device that performs idling stop control is disclosed.

JP 2013-189879 A

  By the way, in the power supply system of a vehicle, it is considered that the power supply state may unintentionally shift from the on state to the off state. If such unintended state transition occurs during the automatic engine stop, the engine is automatically restarted. There may be a situation where the start cannot be performed. However, after the power supply state is unintentionally turned off, it is not an abnormal situation that the engine cannot be automatically restarted under the off state. The occurrence of inconvenience that it is not determined that it has occurred can be considered.

  It is a technical object of the present invention to provide an engine control device that can appropriately determine that an abnormality has occurred in the transition of the power supply state when performing idling stop control.

  In the present invention, when an operation signal is output in response to manual operation of the power switch, the battery power supply state is determined based on the state transition pattern determined in accordance with the vehicle state, and the engine can be operated. Applied to a vehicle that is transitioned between an on-state and a non-on-state that is not the on-state. When the power supply state is on-state, the engine is automatically stopped when a predetermined automatic stop condition is satisfied. And idling stop control means for automatically restarting the engine when a predetermined automatic restart condition is satisfied, and the power supply state is defined by the state transition pattern from the on state under the state where the engine is automatically stopped. A state determination unit that determines whether or not a transition has been made to a non-existing state, and a power supply state is not defined by the state transition pattern by the state determination unit. If it is determined that the transition to the state, characterized in that it comprises an abnormality determination means for determining a transition abnormal power supply state has occurred, the.

  In the above invention, when the engine is automatically stopped, it is determined whether or not the power supply state has transitioned from the on state to a state not defined by the state transition pattern, and it has been determined that such a state transition has occurred. In this case, it is determined that a transition abnormality of the power supply state has occurred. In this case, the abnormality determination can be appropriately performed by determining the abnormality of the state transition in consideration of the state transition pattern in the engine automatic stop state.

The block diagram which shows schematic structure of an engine control system. Explanatory drawing about the transition of an electric power supply state. The flowchart of the process sequence of idling stop control. The flowchart of an abnormality determination process. Explanatory drawing of the example of an abnormality determination process.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the engine control system.

  In FIG. 1, the engine control system includes a battery 11, a power supply ECU 10 that switches a power supply state of the battery 11, a push-type power switch 12, a brake sensor 13, a shift position sensor 14, and an accessory device 16 that is an in-vehicle various electrical equipment, An engine ECU 20 that controls the operating state of the engine, an engine 21, a starter motor 25, relays 15, 17, and 18, various sensors 22 to 24, and the like are provided.

  The power supply ECU 10 and the accessory device 16 are connected via an accessory relay (hereinafter referred to as ACC relay 15), and power supply from the battery 11 to the accessory device 16 is performed by switching the ACC relay 15 on and off. The presence or absence is switched. An ignition relay (hereinafter referred to as IG relay 17) is provided between the power supply ECU 10 and the engine ECU 20, and whether or not power is supplied from the battery 11 to the engine ECU 20 by switching the IG relay 17 on and off. Is switched. Further, a starter relay (hereinafter referred to as STA relay 18) is provided between the power supply ECU 10 and the starter motor 25, and switching from the battery 11 to the starter motor 25 by switching the STA relay 18 on and off. The presence or absence of power supply is switched. Such switching of the relays is performed by the power supply ECU 10.

  The power switch 12 is a push button type switch, and outputs an operation signal (an ON signal that is a switching signal for switching the power supply state) every time the power switch 12 is pushed by the user. The brake sensor 13 detects a depression state of a brake pedal (not shown), and outputs a depression signal when the brake pedal is depressed.

  The shift position sensor 14 detects a shift position of a transmission (not shown) mounted on the vehicle. That is, the shift position sensor 14 detects whether a shift lever (not shown) is in a drive position (D), neutral position (N), parking position (P), back position (B), or the like. A position signal based on the result is output.

  The power supply ECU 10 takes in an operation signal output from the power switch 12, a depression signal output from the brake sensor 13, and a position signal output from the shift position sensor 14, and the power supply state of the battery 11 is based on these signals. Are switched to a power off state (OFF state), an accessory state (ACC state), an on state (IG state), and an engine start state (STA state). Of these states, the OFF state and the ACC state correspond to the “non-on state”.

  The OFF state is a state in which power is not supplied to the accessory device 16 and the engine 21. The ACC state is a state in which power is supplied to the accessory device 16 and power is not supplied to the engine 21. In the ACC state, the ACC relay 15 is switched on, and the power of the battery 11 is supplied to the accessory device 16 via the ACC relay 15. The accessory device 16 is, for example, a car navigation system or an audio device.

  The IG state is a state in which power is supplied to both the accessory device 16 and each part of the engine control system. In the IG state, the ACC relay 15 is turned on and the power of the battery 11 is supplied to the accessory device 16, and the IG relay 17 is turned on and the power of the battery 11 is supplied to the engine ECU 20.

  The STA state is a state in which power is supplied to the accessory device 16 and each part of the engine control system, and power is supplied to the starter motor 25 in order to start the stopped engine 21. In the STA state, the STA relay 18 is turned on and the power of the battery 11 is supplied to the starter motor 25. When the starter motor 25 is driven in the STA state, cranking of the engine 21 is started. After the start of the engine 21 is completed, the operation state of the engine 21 is continued by automatically changing from the STA state to the IG state.

  The engine ECU 20 captures signals from various sensors that detect the operating state of the vehicle and the engine 21 such as the brake sensor 13, the shift position sensor 14, the vehicle speed sensor 22, the water temperature sensor 23, the accelerator sensor 24, and the like, thereby changing the operating state of the engine 21. Control.

  Specifically, the engine ECU 20 performs idling stop control as control of the operating state of the engine 21. In the idling stop control, the engine 21 is automatically operated when it is determined that a predetermined automatic stop condition is satisfied based on the signals acquired from the sensors 22 to 24 in a state where the depression signal of the brake sensor 13 is acquired. Stop. Then, control is performed to automatically restart the engine 21 when it is determined that the depression signal of the brake sensor 13 has not been acquired and a predetermined automatic restart condition is satisfied. For example, the accelerator operation amount is zero, the brake operation is performed, the vehicle speed is equal to or lower than a predetermined value (for example, 10 km / h or lower), and the cooling water temperature of the engine 21 is equal to or higher than a predetermined temperature (for example, 35 ° C.). Based on the fact that the state of charge (SOC) of the battery 11 is equal to or higher than a predetermined value (for example, 80% or higher), it is determined that the automatic stop condition is satisfied. Further, it is determined that the automatic restart condition is satisfied when the brake operation is released.

  By the way, when the push type power switch 12 is used, the on / off state of each relay is not mechanically held unlike the case where the key type power switch is used. For this reason, there is a concern that the state of each relay may change unintentionally due to some malfunction, resulting in an unintended transition of the power supply state. In addition, when the engine 21 is automatically stopped and the transition to the OFF state occurs due to the unintended transition of the power supply state, there is a possibility that the engine 21 cannot be automatically restarted.

  The transition operation of the power supply state performed by the power supply ECU 10 based on the operation signal of the power switch 12 will be described. FIG. 2 is an explanatory diagram showing a state transition pattern of the power supply state. FIG. 2 shows state transitions when the power switch 12 is pushed in each of the OFF state, the ACC state, the IG state, and the STA state. In particular, in the IG state, when the engine is stopped (during automatic stop), the engine The state transition in each during rotation is shown. Here, in particular, the state transition in the brake-on state where the brake pedal is depressed will be described in detail.

  First, the case where the shift position is in the P range will be described. When the power switch 12 is pushed in the brake-on state, if the power supply state is any of the OFF state, the ACC state, and the IG state when the engine is stopped, the state transits to the STA state. As a result, the engine is started. When the power switch 12 is pushed while the engine is rotating and the brake is on, the power supply state changes from the IG state to the OFF state. The state transition in the P range and the brake off state is as shown in the figure.

  When the shift position is in the N range, the state transition when the power switch 12 is pushed in the brake-on state is the same as the state transition in the P range. When the power switch 12 is pushed while the engine is rotating and the brake is on, the power supply state transitions from the IG state to the ACC state. The state transition in the N range and the brake off state is as shown in the figure.

  Furthermore, when the shift position is in a range other than the P or N range (D range), when the power switch 12 is pushed in the brake on state, the power supply state is changed from the OFF state to the IG state (however, the engine is stopped), ACC. Transition from state to IG state (however, the engine is stopped). When the power switch 12 is pushed while the engine is rotating and the brake is on, the power supply state transitions from the IG state to the ACC state. The state transition in the D range and the brake off state is as shown in the figure.

  Here, assuming an automatic stop by idling stop control, the shift position is in the D or N range and the brake is on, and even if the power switch 12 is pushed in this state, the state transition from the IG state is Not specified. That is, during the automatic stop by the idling stop control, even if the power switch 12 is pushed, the transition to the ACC state or the OFF state does not occur.

  In the present embodiment, a state in which the power supply state is not defined by the state transition pattern from the IG state during the automatic stop of the engine 21 using the state transition pattern defined as described above (OFF state). It is determined whether or not a transition abnormality of the power supply state has occurred when it is determined whether or not an unspecified state transition has occurred. When it is determined that a power supply state transition abnormality has occurred, the abnormality occurrence information is stored in a backup memory such as a flash memory and used for subsequent abnormality diagnosis. The abnormality occurrence information may be stored together with history information such as the total travel distance of the vehicle, the travel distance since the IG state, and the travel time after the IG state.

  Next, engine control performed by the engine ECU 20 will be described. FIG. 3 is a flowchart of a processing procedure for idling stop control. The process of FIG. 3 is started when the power supply state becomes the IG state, and thereafter repeatedly performed in predetermined steps.

  First, in step S11, it is determined whether or not the brake is depressed (ON). If a positive determination is made, it is determined in step S12 whether the engine stop flag is off. The engine stop flag is turned on when it is determined that the engine 21 is in a stopped state in the process described later.

  If it is determined that the engine stop flag is off, it is determined in step S13 whether an automatic stop condition is satisfied. For example, when there is no input signal accompanying the accelerator operation, it is determined that the automatic stop condition for the engine 21 is satisfied when the vehicle speed is less than a predetermined value.

  If the determination is affirmative, the engine 21 is stopped in step S14, and the engine stop flag is turned on in subsequent step S15. It is also possible to turn on the engine stop flag when the vehicle speed becomes zero after instructing the engine stop.

  On the other hand, if it is determined in step S12 that the engine stop flag is on, the process proceeds to step S16, and abnormality determination processing is performed. FIG. 4 shows a flowchart of the abnormality determination process performed in step S16 of FIG. First, in step S20, it is determined whether or not the power supply state is other than the OFF state. Note that the determination of which state the power supply state is in may be implemented by monitoring the states of the ACC relay 15 and the IG relay 17, for example. When it is determined that the power supply state is the ACC state or the IG state and is not the OFF state, the process proceeds to step S21, and it is determined that the power supply state transition abnormality has not occurred.

  If it is determined in step S20 that it is in the OFF state, the process proceeds to step S22, and it is determined that a power supply state transition abnormality has occurred. Then, the process proceeds to step S23, and the travel history of the vehicle is acquired. At the subsequent step S24, information on the occurrence of abnormality is stored in association with the travel history. When an abnormality occurs, an abnormality warning lamp provided on the instrument panel or the like may be turned on.

  Returning to the description of FIG. 3, if it is determined in step S11 that the brake is off, the process proceeds to step S17 to determine whether or not the engine stop flag is on. If the determination is affirmative, the engine stop flag is turned off in step S18, and the process proceeds to step S19. In step S19, the engine 21 is automatically restarted.

  Next, an execution example of the above process will be described with reference to FIG. FIG. 5 shows the transition of the power supply state from the vehicle stop state, and the initial power supply state is the OFF state.

  When the power switch 12 is pressed at time t1, an operation signal is generated. At this time, if the shift position is in the P range and the brake is on, the power supply state transitions from the OFF state to the STA state. Thereafter, when the start (cranking) of the engine 21 is completed, the engine 21 enters an operating state, and the power supply state automatically transitions to the IG state. The engine speed NE changes according to changes in the cranking state and the operating state.

  Thereafter, when the automatic stop condition is satisfied at time t2, the engine 21 is automatically stopped. During the engine stop, it is determined whether there is a transition abnormality in the power supply state. In this case, during the automatic stop, the shift position is originally in the D range (or N range) and the brake is on, and even if the user presses the power switch 12, the power supply state does not change at all and is OFF. There should be no transition to the state. However, when a transition abnormality occurs due to some trouble, the power supply state unintentionally transitions to the OFF state as at time t3, and it is determined that the abnormality has occurred by the state transition. In this case, when the power supply state transitions to the OFF state, automatic restart is not performed even if the restart condition is subsequently satisfied. However, since the history of the transition of the power supply state to the OFF state (abnormality occurrence information) is stored, the cause of the automatic restart failure can be specified.

  According to the above, the following excellent effects can be obtained.

  (1) From the state in which the engine 21 is automatically stopped by the idling stop control, the failure of the engine 21 not being automatically restarted even if the automatic restart condition is satisfied may be caused by a power supply state unintentionally other than the on state. A transition to the non-on state is assumed. In this case, the fact that the automatic restart of the engine 21 is not performed in a non-on state is not an abnormal situation. Therefore, even if an attempt is made to identify the cause of the automatic restart being impossible, the cause This is thought to impede the identification. Then, considering this point, it is determined whether the power supply state has transitioned from an on state to a state not defined by the state transition pattern under a state in which the engine 21 is automatically stopped. When it is determined that the power supply state has occurred, it is determined that a power supply state transition abnormality has occurred. In this case, the abnormality determination can be appropriately performed by determining the abnormality of the state transition in consideration of the state transition pattern in the engine automatic stop state.

  (2) In the state where the engine 21 is automatically stopped, the state transition from the IG state does not occur even when the power switch 12 is pressed. Therefore, when it is detected that the vehicle is in the off state under the automatic stop state, it is not determined by the switch operation, and it is determined that the power supply state is unintentionally shifted to the off state, that is, an abnormal state transition has occurred. Can do.

  (3) When the power supply state is the IG state, the state transition mode (transition pattern) differs depending on whether or not the engine 21 is in the automatic stop state. If the engine 21 is in the automatic stop state, the operation signal Even if output occurs, the power supply state does not change. In this case, since the state transition under the automatic stop state of the engine 21 is prohibited, it can be appropriately determined that an abnormal state transition has occurred.

  (4) When it is determined that a power supply state transition abnormality has occurred, the travel information of the vehicle is stored together so that the cause of the abnormality can be suitably removed thereafter.

  The present invention is not limited to the description of the above embodiment, and may be implemented as follows.

  -It is good also as a structure which determines with the transition abnormality of a power supply state having arisen, when the power supply state changes to the ACC state unintentionally during the engine 21 automatic stop. Also in this case, since the power supply state has transitioned from the IG state to an unspecified state, it is still determined that a power supply state transition abnormality has occurred.

  The state transition pattern of the power supply state may be defined so that the state transition from the IG state to the ACC state occurs when the power switch 12 is pushed while the engine 21 is automatically stopped. That is, when the power switch 12 is pushed during the automatic stop, the state is changed to the ACC state but not changed to the OFF state. Even in such a configuration, during the automatic stop of the engine 21, it is determined whether or not the power supply state has transitioned from the IG state to a state (OFF state) that is not defined by the state transition pattern. When it is determined that a power supply state has occurred, it may be determined that a power supply state transition abnormality has occurred.

  Note that when the transition is made to the ACC state during the automatic stop, the automatic restart fails as in the case of the transition to the OFF state, but this treatment itself is not abnormal. In this configuration, whether or not the automatic restart failed in both the transition to the ACC state and the transition to the OFF state during the automatic stop, and whether or not the power supply state transition abnormality occurred due to the failure of the automatic restart alone Is unknown, but it is possible to identify the cause by leaving history information that a transition abnormality has occurred.

  -When an abnormality occurs in which the power supply state transitions from the IG state to the OFF state while the engine 21 is automatically stopped, information on the occurrence of the abnormality is stored in association with the travel history, and the cause is specific May be specified. Possible causes of the power supply state unintentionally transitioning from the IG state to the OFF state are assumed to be a mechanical failure such as disconnection or an abnormality in signal processing such as erroneous determination of a signal by the power supply ECU 10. When such a power supply state transition abnormality occurs, when the cause is a disconnection, it is considered that self-recovery from the abnormal state does not occur. That is, it is considered that the OFF state is maintained as it is. On the other hand, when the cause is an erroneous determination of signal processing by the ECU 50, self-recovery from the abnormal state may occur. That is, there is a possibility of returning from the OFF state to the IG state. Therefore, after determining that a transition abnormality of the power supply state has occurred, information on whether or not the power supply state returns to the IG state is acquired. By detecting such a change in the power supply state, it is possible to more specifically identify the cause of the abnormality, which can be used for diagnosis for removing the cause of the abnormality.

  In the above, an example is shown in which the abnormality determination is performed when the engine stop flag is on, that is, when the engine 21 is automatically stopped. In addition to this, when there is an automatic restart request of the engine 21, when it is determined that the automatic restart has not been performed, the abnormality determination shown in FIG. 4 may be performed. That is, in FIG. 3, when it is determined in step S19 that there is a request for automatic restart, and it is determined that the engine 21 has not been automatically restarted even after a predetermined time has elapsed, the abnormality determination in FIG. These processes may be performed.

  The power switch 12 may be a switch other than the push-type switch, for example, a touch-type switch, a slide-type switch, or a rotary-type switch. In any case, what is necessary is just to output a binary operation signal (ON signal) according to the manual operation of the user.

  DESCRIPTION OF SYMBOLS 11 ... Battery, 12 ... Power switch, 20 ... Engine ECU, 21 ... Engine.

Claims (5)

When an operation signal is output in response to a manual operation of the power switch (12), the power supply state of the battery (11) is determined based on the state transition pattern determined in accordance with the state of the vehicle. Applied to a vehicle that is transitioned between an on-state where the vehicle is drivable and a non-on-state that is not the on-state,
An idling stop control that automatically stops the engine when a predetermined automatic stop condition is satisfied and automatically restarts the engine when a predetermined automatic restart condition is satisfied when the power supply state is on. Means,
State determination means for determining whether or not the power supply state has transitioned from the on state to a state not defined by the state transition pattern under a state in which the engine is automatically stopped;
An abnormality determination unit that determines that a transition abnormality of the power supply state has occurred when the state determination unit determines that the power supply state has transitioned to a state that is not defined by the state transition pattern;
An engine control device comprising: The non-on state includes an accessory state that enables power supply to the vehicle-mounted electrical device (16) and an off state that disables power supply to the electrical device,
In the state transition pattern, when the operation signal is output by manual operation of the power switch under the automatic stop state of the engine, the power supply state is left in the on state or the accessory state is set. Is defined to transition,
The state determination means determines whether the power supply state has transitioned from the on state to the off state under an automatic stop state of the engine,
The engine control apparatus according to claim 1, wherein the abnormality determination unit determines that a transition abnormality of the power supply state has occurred when the state determination unit determines that the power supply state has transitioned to the off state. . In the state transition pattern, when the power supply state is the on state, if the engine is not in the automatic stop state, the power supply state is transitioned to the non-on state according to the output of the operation signal, If the engine is in an automatic stop state, the power supply state is defined to remain in the on state according to the output of the operation signal,
The state determination means determines whether the power supply state has transitioned from the on state to the non-on state under an automatic stop state of the engine,
The engine control according to claim 1, wherein the abnormality determination unit determines that a transition abnormality of the power supply state has occurred when the state determination unit determines that the power supply state has transitioned to the non-on state. apparatus.   The abnormality determining means determines that the transition abnormality is caused by signal processing when the power supply state self-returns to the on state after determining that a transition abnormality of the power supply state has occurred. The engine control device according to any one of claims 1 to 3, wherein when the power supply state does not self-return to an on state, the transition abnormality is determined to be caused by a disconnection.   When it is determined that a transition abnormality of the power supply state has occurred, travel information including either the total travel distance of the vehicle, the travel distance after the power supply state transitions to the on state, or the elapsed time The engine control apparatus according to any one of claims 1 to 4, further comprising a storage unit that acquires and stores information indicating that the transition abnormality has occurred and the travel information in association with each other.

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