JP3967423B2 - Vehicle control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle control apparatus suitable for use in a cylinder direct-injection internal combustion engine equipped with an electronic throttle control apparatus (drive-by-wire).
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an engine such as an automobile, a drive-by-wire (hereinafter referred to as “DBW”) has been developed that communicates between an accelerator pedal and a throttle valve with an electric signal. In such DBW, the accelerator pedal and the throttle valve are not mechanically connected, and the virtual accelerator opening is calculated by a computer based on various parameters in addition to the operation amount of the accelerator pedal (accelerator opening). (Pseudo accelerator opening) can be set and the throttle valve can be controlled in accordance with this, which is also referred to as an electronic throttle control device.
[0003]
Therefore, for example, during idle operation when the accelerator pedal is not operated (that is, the accelerator opening is less than a predetermined value), the idle speed can be controlled while finely adjusting the throttle valve. By setting the pseudo accelerator opening so as to correct the accelerator opening (operating by the driver) according to the driving state of the vehicle, the engine can be operated with good feeling by throttle control based on this. .
[0004]
On the other hand, in recent years, an internal combustion engine (generally a gasoline engine) that ignites sparks with an ignition plug and a spark ignition type in-cylinder injection internal combustion engine (hereinafter referred to as an engine) that directly injects fuel into the cylinder has been put into practical use. Has been. In such an engine, it is possible to achieve both improvement in the fuel efficiency performance and improvement in the output performance of the engine by utilizing the characteristic that the fuel injection timing can be freely controlled and the formation state of the air-fuel mixture can be freely controlled.
[0005]
In other words, in this spark ignition type in-cylinder injection engine, the fuel is injected in the compression stroke, so that the fuel is operated in a very lean state (that is, the air-fuel ratio is extremely larger than the stoichiometric air-fuel ratio) due to the stratified combustion ( (Super-lean combustion operation) can be performed, and the super-lean operation mode (compression stroke injection mode) is provided as the combustion mode, so that the fuel consumption rate can be greatly improved.
[0006]
In a spark ignition type cylinder injection engine, a premixed combustion operation in which fuel is mainly injected in the intake stroke can be naturally performed. In this case, by directly injecting fuel into the combustion chamber (inside the cylinder), Since most of the fuel injected in each combustion cycle can be reliably burned in the combustion cycle, the engine output can be improved.
[0007]
Such a premixed combustion operation is also performed in a lean state of fuel (that is, the air-fuel ratio is larger than the theoretical air-fuel ratio), although not as much as the super-lean operation mode, and an intake lean operation mode. O so that the air-fuel ratio becomes the stoichiometric air-fuel ratio. ₂ A stoichiometric operation mode (stoichio feedback operation mode) in which feedback control is performed based on sensor information and the like, and an enrich operation mode (in which the air-fuel ratio is smaller than the stoichiometric air-fuel ratio) (open) Loop mode) can be set as the combustion mode.
[0008]
In general, if the required output to the engine is small, that is, if the engine speed is low and the load is small, the fuel consumption is improved as a compression lean operation mode, and as the engine speed and engine load increase more than this, The intake lean operation mode, the stoichiometric operation mode, and the enrich operation mode are selected in this order.
[0009]
By the way, in the case of super lean combustion operation (compression lean operation), in order to increase the air-fuel ratio, it is necessary to supply more air to the combustion chamber. This compression lean operation is a region where the engine load is low, that is, Since the operation is performed in a region where the amount of depression of the accelerator pedal (accelerator opening) is small, the required air-fuel ratio cannot be satisfied with the throttle valve opening corresponding to the accelerator opening.
[0010]
Therefore, an air bypass passage that bypasses the intake passage provided with the throttle valve is provided, and an electronic control valve (air bypass valve) is provided in the air bypass passage. Therefore, a technique has been developed in which the air bypass valve is opened according to the required air amount to supply air.
[0011]
[Problems to be solved by the invention]
By the way, it is also conceivable to apply the aforementioned drive-by-wire (DBW) to the above-described spark ignition type in-cylinder injection type engine. In other words, the DBW can control the throttle valve opening without corresponding to the accelerator opening, so that a larger amount of air than the amount corresponding to the accelerator opening can be supplied to the combustion chamber, and spark ignition type cylinder injection Even when the accelerator opening is small, for example, during the compression lean operation of the type engine, the required amount of air can be supplied to the combustion chamber.
[0012]
However, when adopting such a DBW, it is desirable to prepare a countermeasure against an unexpected failure of the DBW, not limited to the cylinder injection type engine.
For example, the cause of the failure of the DBW is not only short-circuiting or disconnection of sensors such as an accelerator opening sensor, but also dust contained in exhaust gas, blow-by gas, etc., which is recirculated by an exhaust gas recirculation device by a throttle valve controlled by the DBW. It is also conceivable that the foreign matter such as is stuck due to biting.
[0013]
If such a DBW fails, the throttle valve opening control by the DBW cannot be performed properly, and the driver's intention to request output cannot be reflected in the engine output.
In particular, reverse operation is usually performed with a low engine output. Therefore, during such reverse operation, if the engine output does not become low, the driving operation becomes difficult. It is.
[0014]
The present invention has been devised in view of the above-described problems, and the electronic throttle control device fails. Teshi It is an object of the present invention to provide a vehicle control device that can ensure stable running performance of a vehicle even when the vehicle is stuck, and in particular, can ensure operability when reversing.
[0015]
[Means for Solving the Problems]
For this reason, the vehicle control apparatus according to the first aspect of the present invention is a vehicle including an engine having an electronic throttle control device for electrically driving a throttle valve, and a transmission connected to the output shaft of the engine. A control device for detecting that the electronic throttle control device is malfunctioning Therefore, it can be detected from the failure signal and the opening information of the throttle valve that the throttle valve is malfunctioning due to the valve closing and sticking at a predetermined opening or less. Failure detection means, accelerator opening detection means for detecting the accelerator opening of the engine, By the failure detection means The throttle valve Has been determined to be stuck closed Sometimes , A limp home valve that is installed so as to be able to supply air to each combustion chamber of the engine and is controlled to be turned on and off without adjusting the intake air amount; By controlling the fuel supply to a predetermined cylinder of the engine to stop Output reduction means for reducing the output of the engine; e, The output lowering means is When it is detected by the failure detection means that the throttle valve is closed and closed, when the forward gear is selected in the transmission, the accelerator opening detected by the accelerator opening detection means is Reduce the engine output on condition that it is below a predetermined opening, When the reverse gear is selected in the transmission, it responds to the detection result of the accelerator opening detection means. Jar Without always The It is characterized by lowering the engine output.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 5 show a vehicle control apparatus as an embodiment of the present invention, and will be described based on these drawings.
[Overall description of the engine mounted on the vehicle]
First, the engine (internal combustion engine) according to this embodiment is a spark ignition type cylinder injection internal combustion engine (hereinafter also referred to as cylinder injection engine), and the configuration thereof will be described with reference to FIG.
[0020]
In FIG. 2, 1 is an engine body, 2 is an intake passage, 3 is a throttle valve installation portion, and 4 is an air cleaner. The intake passage 2 has a configuration in which an intake pipe 7, a throttle body 5, a surge tank 8, and an intake manifold 9 are connected in this order from the upstream side.
The throttle body 5 is provided with an electronically controlled electronic throttle valve (throttle valve) 15 that is electrically controlled. The electronically controlled throttle valve 15 is a throttle control computer (throttle controller, also referred to herein as ETV) described later. The opening degree is controlled through 160. The target opening of the throttle valve (target throttle opening) is determined by an engine control computer (engine ECU) 16 described later. First It is set according to the depression amount (accelerator opening) of the accelerator pedal 50 and the engine operating state detected by the accelerator position sensor (APS1) 51A.
[0021]
An electronic throttle control device [namely, drive-by-wire (DBW)] 150 (see FIG. 1) is constituted by the electronic control throttle valve 15, the engine ECU 16, the throttle controller 160, and the like.
A limp home valve device (LHV) 12 is provided in parallel with the electronically controlled throttle valve 15. The LHV 12 is for supplying air so that combustion of the engine is established when an electronic control throttle valve failure (closed failure), which will be described later, is established. The LHV 12 is upstream of the surge tank 8 so as to bypass the electronic control throttle valve 15. The LHV main body 14 is composed of a linear solenoid (not shown) controlled by an engine control computer (engine ECU) 16 described later. It is designed to be driven.
[0022]
Reference numeral 17 denotes an exhaust passage, and 18 denotes a combustion chamber. The intake passage 2 and the openings of the exhaust passage 17 to the combustion chamber 18, that is, the intake port 2A and the exhaust port 17A are equipped with an intake valve 19 and an exhaust valve 20. Has been. Furthermore, 21 is a fuel injection valve (injector), and in this embodiment, the injector 21 is disposed so as to inject fuel directly into the combustion chamber 18.
[0023]
Further, 22 is a fuel tank, 23A to 23E are fuel supply passages, 24 is a low pressure fuel pump, 25 is a high pressure fuel pump, 26 is a low pressure regulator, 27 is a high pressure regulator, and 28 is a delivery pipe. Is driven by a low-pressure fuel pump 24 and further pressurized by a high-pressure fuel pump 25 to be supplied to the injector 21 through fuel supply passages 23A and 23B and a delivery pipe 28 in a predetermined high-pressure state. At this time, the fuel pressure discharged from the low-pressure fuel pump 24 is regulated by the low-pressure regulator 26, and the fuel pressure pressurized by the high-pressure fuel pump 25 and guided to the delivery pipe 28 is regulated by the high-pressure regulator 27. It has become.
[0024]
Further, 29 is an exhaust gas recirculation passage (EGR passage) for recirculating a part of the exhaust gas to the intake passage 2, and 30 is an EGR valve (exhaust gas amount adjusting means) for adjusting the recirculation amount of the exhaust gas through the EGR 29. 32 is a flow path for reducing blow-by gas, 33 is a valve for positive ventilation in the crank chamber, 34 is a canister, and 35 is a catalyst for purifying exhaust gas (here, a three-way catalyst).
[0025]
As shown in FIG. 2, the engine ECU 16 performs drive control of the injector 21, drive control of an ignition coil that operates a spark plug (not shown), opening control of the EGR valve, fuel pressure control by the high pressure regulator 27, and the like. In addition, the control of the LHV 12 is performed in accordance with the engine operating state or failure state. The throttle controller 160 controls the opening / closing of the electronically controlled throttle valve 15 in accordance with the driver's accelerator command, the engine operating state, and the failure state.
[0026]
Therefore, the engine ECU 16 detects a first accelerator position sensor (APS1) 51A, an air flow sensor (not shown), an intake air temperature sensor 36, and a throttle opening, as shown in FIG. Second Throttle position sensor (TPS 2 37B, idle switch 38, air conditioner switch (not shown), shift position sensor (not shown), vehicle speed sensor (not shown), power steering switch (not shown) for detecting the operating state of the power steering, starter switch (not shown) , First cylinder detection sensor 40, crank angle sensor 41, water temperature sensor 42 for detecting the cooling water temperature of the engine, O for detecting the oxygen concentration in the exhaust gas. ₂ A detection signal is transmitted from the sensor 43 or the like. Since the engine speed (engine speed) can be calculated based on the crank angle sensor 41, the crank angle sensor 41 is referred to as an engine speed sensor for convenience.
[0027]
Further, as shown in FIG. Second Accelerator position sensor (APS 2 51B, First Throttle position sensor (TPS 1 ) A detection signal is transmitted from 37A or the like.
The engine ECU 16 and the throttle controller 160 are configured to exchange information by communication with each other.
[0028]
Further, the engine is provided with an automatic transmission (AT) 170 and an automatic transmission controller (AT controller) 171 for controlling the automatic transmission 170, and between the engine ECU 16 and the AT controller 171. Information is exchanged by communication.
The engine is also provided with an auto-cruise function, and throttle opening control by the throttle controller 160 is performed in accordance with input information related to auto-cruise.
[0029]
By the way, in this engine, there are a late lean combustion operation mode (compression stroke injection mode), a first lean fuel combustion operation mode, a stoichiometric feedback operation combustion operation mode, and an open loop combustion operation mode. One of these modes is selected according to the state (that is, the engine speed and the engine load), the traveling state of the vehicle, and the like.
[0030]
Of these, in the late lean combustion operation mode, fuel injection is performed at a stage very close to the ignition timing as in the latter half of the compression stroke, and the fuel is collected in the vicinity of the spark plug to be partially rich and made lean overall. However, this is a mode in which stratified combustion is performed, and is an ultra-lean combustion mode in which saving operation can be performed while ensuring ignitability and combustion stability. In this embodiment, the total air-fuel ratio is set to a region of about 24 or more, and the leanest combustion can be realized. However, the total air-fuel ratio is lower than that of this embodiment (for example, the total air-fuel ratio is about It may be set to a range of about 23 or more), or may be set to a region higher than that of the present embodiment.
[0031]
The first lean lean operation mode is also a lean combustion mode. In this mode, fuel injection is performed before the second lean combustion operation mode (mainly, the intake stroke), and the fuel is premixed to achieve the overall theory. This is a mode in which a saving operation is performed while obtaining a certain level of output while ensuring ignitability and combustion stability while being leaner than the air-fuel ratio. Here, the region of the first lean combustion operation mode is set to a region where the total air-fuel ratio is about 24 or less and the stoichiometric air-fuel ratio or more.
[0032]
The stoichiometric feedback combustion operation mode is O ₂ Based on the output of the sensor, sufficient engine output can be obtained efficiently while maintaining the air-fuel ratio in the stoichiometric state. In this mode, premixed combustion based on fuel injection in the intake stroke is performed.
Further, in the open loop combustion operation mode, combustion is performed at stoichiometric or rich air-fuel ratio by open loop control so that sufficient output can be obtained at the time of acceleration or starting. In this mode, premixed combustion based on fuel injection in the intake stroke is performed.
[0033]
Each of these operation modes is selected by an engine ECU 16 to be described later in accordance with the engine speed and the engine load. Normally, the low lean combustion mode is selected in the low rotation and low load state, and the engine speed is selected. When the engine load increases, the lean combustion operation mode and the stoichiometric combustion operation mode are switched in this order, and when the engine speed and the engine load further increase, the operation mode is switched to the open loop mode (enrich combustion operation mode).
[0034]
The engine ECU 16 performs various controls after selecting the operation mode as described above. Focusing on the throttle valve control, in the late lean combustion operation mode in which the fuel is injected during the compression stroke and the air-fuel ratio is extremely large, the target air-fuel ratio is selected. To achieve this, air is insufficient at the throttle valve opening according to the accelerator opening, so a target opening (pseudo target opening) that is significantly larger than the throttle valve opening according to the accelerator opening is set. Based on this, the opening degree of the throttle valve is controlled. In addition, even in the stoichiometric feedback combustion operation mode and the open loop combustion operation mode, there is a case where the air is insufficient at the throttle valve opening corresponding to the accelerator opening. In this case, the throttle valve opening corresponding to the accelerator opening. A target opening (pseudo target opening) that is appropriately larger than that is set, and the opening degree of the throttle valve is controlled based on the target opening.
[Description of intake control system]
Here, the electronic throttle control device (DBW) 150 and the LHV 12 control system (that is, the limp home valve control device) 120 relating to the control device of the present invention will be described. As shown in FIG. Configured.
[0035]
That is, the electronically controlled throttle valve 15 constituting the DBW 150 is externally attached to the butterfly valve 151 interposed in the intake passage 5A in the throttle body 5 and the shaft 152 that supports the butterfly valve 151, and the butterfly valve 151 is closed. A return spring 153 for applying a force, an electric motor (throttle actuator) 154 for rotating the shaft 152, and a gear mechanism 155 interposed between the actuator 154 and the shaft 152 are provided.
[0036]
The shaft 152 has a first throttle position sensor (TPS1) 37A for detecting the opening degree of the butterfly valve 151 (throttle valve opening degree) 37A and a second throttle position sensor (TPS2). 37B And are attached. Thus, in this apparatus, as the throttle position sensor 37, First and second Two throttle position sensors (TPS1, TPS2) 37A, 37B are provided. First and second This is provided when the throttle position sensors 37A and 37B fail.
[0037]
The DBW 150 controls the operation of the actuator 154 based on the electronic throttle valve 15, the engine ECU 16 that sets the target opening of the electronic control throttle valve 15, and the target opening set by the engine ECU 16. The throttle controller 160 adjusts the throttle valve opening.
[0038]
For this reason, as shown in FIG. 1, the engine ECU 16 is provided with a target opening setting unit 16A, and the throttle controller 160 is provided with a throttle opening feedback control unit 160A.
FIG. 3 is a control block diagram focusing on the throttle control. As shown in FIG. 3, the target opening degree setting unit 16A of the engine ECU 16 includes detection information and a crank angle from the first accelerator position sensor (APS1) 51A. A function 16a for setting the target engine torque from the engine speed obtained from the detection result of the sensor 41 (see FIG. 2), a function 16b for performing intake air temperature correction and atmospheric pressure correction to the set target engine torque, and an air conditioner , A function 16c for correcting the electric load and the like, and a function 16d for setting the target throttle opening from the corrected target engine torque and engine speed.
[0039]
The target opening setting unit 16A further includes a function 16e for setting a dashpot control opening based on detection information from the second throttle position sensor (TPS2) 37B, and an engine detected by the water temperature sensor (WTS). A function 16f for setting the idle speed control opening according to the cooling water temperature information and the like, and a function 16g for selecting the maximum value from these setting opening degrees are provided. Is output to the throttle controller 160 as the target opening of the throttle valve.
[0040]
The throttle opening feedback control unit 160A of the throttle controller 160 determines the motor drive current according to the throttle valve target opening output from the engine ECU 16, and controls the driving of the actuator (also referred to as a throttle control servo) 154. However, at this time, in the throttle controller 160, the throttle valve is feedback-controlled according to the throttle valve opening (actual opening) detected by the first throttle position sensor (TPS1) 37A.
[0041]
By the way, in this apparatus, as shown in FIG. First and second As in the case of the throttle position sensors (TPS1, TPS2) 37A, 37B, the accelerator position sensor 51 is also provided with a first accelerator position sensor (APS1) 51A and a second accelerator position sensor (APS2) 51B. However, this is also provided at the time of failure.
[0042]
The detection signal from the first accelerator position sensor (APS1) 51A is input to the engine ECU 16 and used to set the throttle valve target opening, and the detection signal from the second accelerator position sensor (APS2) 51B is used as the throttle controller 160. When the first accelerator position sensor 51A fails, the detection signal of the second accelerator position sensor 51B is transmitted from the throttle controller 160 to the engine ECU 16 by communication to be used for setting the throttle valve target opening. It has become.
[0043]
Also for the throttle position sensor, the detection signal of the first throttle position sensor (TPS1) 37A is input to the throttle controller 160 to be used for feedback control of the throttle valve, and the detection signal of the second throttle position sensor (TPS2) 37B is In addition to being input to the engine ECU 16 and used for the above-described dashpot control or the like, the second throttle position sensor 37B is used when the first throttle position sensor 37A fails. of A detection signal is transmitted from the engine ECU 16 to the throttle controller 160 by communication and used for feedback control of the throttle valve.
[0044]
On the other hand, the limp home valve device 12 includes a bypass passage 13 provided in parallel with the intake passage 5A in the throttle body 5 (that is, between the upstream side and the downstream side of the butterfly valve 151 of the electronically controlled throttle valve 15). In this bypass passage 13 Provided The LHV main body 14, a linear solenoid (not shown) that drives the LHV main body 14 to open and close, and an engine ECU 16 that controls the operation of the linear solenoid, and its control system (limp home valve control device) 120 include a linear solenoid, It is comprised from engine ECU16.
[0045]
The limp home valve device 12 is provided to cope with an emergency failure of the DBW 150. In this device, the engine ECU 16 and the throttle controller 160 perform various failure determinations as a countermeasure against such failure of the DBW 150. Thus, for each failure determination, for example, the limp home valve device 12 is used to perform the corresponding processing.
[0046]
As shown in FIG. 1, a power supply relay 62 is interposed in the power supply circuit from the battery 61 to the throttle controller 160 so that it can be used for this failure handling process. It can be turned off. Reference numeral 180 denotes a warning light that is turned on during limp home processing.
Here, each failure determination process will be described. This failure determination process is performed based on various detection information and control information by a failure determination means (failure detection means) 70 provided in the engine ECU 16 and the throttle controller 160. Specifically, the failure determination process is as follows. Each determination process is performed.
[0047]
A. Position feedback failure
First, a determination process for a failure (position feedback failure) in which the opening degree (position) of the electronic control throttle valve 15 cannot be adjusted as instructed will be described.
The failure of position feedback includes (1) valve system sticking (including fully closed sticking) and (2) motor output open fault. When a position feedback fault signal is received, it is determined as a fault.
[0048]
However, (1) the ignition switch is on. (2) The motor relay is on, or a communication abnormality from the engine ECU 16 to the throttle controller 160 has occurred. (3) The battery voltage Vb is equal to or greater than a predetermined value. (4) An abnormality in communication from the throttle controller 160 to the engine ECU 16 has not occurred. This failure determination is performed when all of the failure determination preconditions are satisfied.
[0049]
One of the position feedback failures is that the electronic control throttle valve 15 is stuck. In this case, the opening degree of the electronic control throttle valve 15 stuck by the first throttle position sensor (APS1) 37A can be detected. Therefore, based on the opening information, when the throttle valve 15 is stuck at a first predetermined opening or more (valve open sticking), an open sticking handling process (valve open sticking fail process) is performed, and the throttle valve 15 is When it is stuck at a predetermined opening or less (valve closed sticking), a closed sticking handling process (valve closed sticking fail process) is performed.
[0050]
In the open sticking handling process (valve open sticking fail process), the following processes are performed.
(1) In order to limit the intake air amount, the LHV 12 is turned off (closed).
(2) The fuel injection mode is limited to the compression lean mode (the forced compression lean mode is used).
(3) The fuel supply to some cylinders (for example, 3 cylinders for a 6-cylinder engine) is stopped (partial cylinder fuel cut).
[0051]
(4) Stop the EGR control (EGR cut).
(5) If the engine speed Ne is within a predetermined high speed range (Ne≥3000 rpm), the fuel supply is stopped (fuel cut) for all cylinders.
{Circle around (6)} Auxiliary machines driven by the engine that do not adversely affect the engine operation due to the stoppage are set to stop the operation (here, the air conditioner is stopped).
[0052]
In addition, as the valve closed fixed fail processing, the late lean combustion operation mode and the early lean combustion operation mode included in the lean combustion mode are selected as the operation mode so that stable combustion can be performed even with a small intake amount. The process of prohibiting is performed. That is, as the valve-closed and stuck-failure process, a process for switching the operation mode to the theoretical air-fuel ratio mode (stoichiometric feedback operation combustion operation mode, open loop combustion operation mode) is performed.
[0053]
In addition, when the valve is malfunctioning (including valve closing sticking) other than when the valve is stuck open, it is difficult to secure the intake air amount through the throttle valve. In order to secure the intake air, limp home processing is performed.
B. Motor failure
The motor failure includes (1) motor ground fault and (2) motor power fault (overcurrent detection). When a motor output ground fault and power fault signal is received, it is determined that the motor is faulty. However, (1) the motor relay is on. (2) Communication abnormality from the throttle controller 160 to the engine ECU 16 has not occurred. This failure determination is performed when all of the failure determination preconditions are satisfied. When such a motor failure occurs, limp home mode processing described later is performed.
[0054]
C. TPS failure
The throttle position sensor has first and second TPSs 37A and 37B. The first throttle position sensor (TPS1) 37A used for feedback control by the throttle controller 160 is as follows. (1) Open current circuit Or, there is a failure due to a short circuit and (2) a linearity failure. For the second throttle position sensor (TPS2) 37B, there are a (3) characteristic abnormality and a (4) failure due to an open or short circuit of the current circuit. A failure is determined when a failure signal is received.
[0055]
However, in this failure determination, (1) the ignition switch is on. (2) Communication abnormality from the throttle controller 160 to the engine ECU 16 has not occurred. This is performed when all the failure determination prerequisites are satisfied.
When the first throttle position sensor (TPS1) 37A fails, the throttle valve feedback control is hindered, and therefore, processing for limiting the engine operating range is performed. Further, when the first throttle position sensor (TPS1) 37A fails, the second throttle position sensor (TPS2) 37B has already failed, or a communication abnormality described later (communication abnormality from the engine ECU 16 to the throttle controller 160) occurs. If there is, limp home processing is performed.
[0056]
D. Communication failure
Communication is performed between the engine ECU 16 and the throttle controller 160, and communication failures include a communication abnormality from the engine ECU 16 to the throttle controller 160 and a communication abnormality from the throttle controller 160 to the engine ECU 16.
[0057]
A communication abnormality from the engine ECU 16 to the throttle controller 160 is determined to be a failure when the throttle controller 160 receives a communication failure signal from the engine ECU 16.
However, in this failure determination, (1) the battery voltage Vb is a predetermined value or more. (2) Communication abnormality from the throttle controller 160 to the engine ECU 16 has not occurred. This is performed when all the failure determination preconditions are satisfied.
[0058]
At the time of this communication failure, the target opening of the throttle valve set by the engine ECU 16 cannot be taken in by the throttle controller 160, and there is a high possibility that the intake air amount control cannot be performed appropriately. Therefore, the following processing is performed.
(1) Lean operation prohibition processing
(2) Cruise control control prohibition processing
(3) Fuel cut process at high engine speed (eg Ne ≧ 3000rpm)
A communication abnormality from the throttle controller 160 to the engine ECU 16 is determined as a failure when any of the following conditions is satisfied.
[0059]
(1) There is a checksum error.
(2) There is an overrun framing error.
(3) Communication is not completed for a predetermined time (for example, for 25 msec).
However, in this failure determination, (1) the battery voltage Vb is a predetermined value or more. (2) Cruising switch is off. This is performed when all the failure determination preconditions are satisfied.
[0060]
Even when this communication failure occurs, the engine ECU 16 cannot take in a control signal or the like from the throttle controller 160, and there is a high possibility that the intake air amount control cannot be performed appropriately. Therefore, the following processing is performed.
(1) Send a communication failure to the throttle controller 160
(2) Lean operation prohibition processing
(3) Cruise control control prohibition process
(4) Fuel cut process at high engine speed (eg Ne ≧ 3000rpm)
(5) When the brake is depressed, the command target opening degree of the throttle valve 15 from the engine ECU 16 is clipped to the upper limit.
[0061]
E. Throttle controller failure (ETV failure)
The failure of the throttle controller 160 is determined as a failure when all of the following conditions (1) to (4) are satisfied, or when all the following conditions (5) to (8) are satisfied.
(1) The ignition switch is on.
[0062]
(2) There is no abnormality in the second accelerator position sensor (APS2) 51B and the second throttle position sensor (TPS2) 37B.
(3) An abnormality in communication from the engine ECU 16 to the throttle controller 160 has occurred.
▲ 4 ▼ | (V _APS2 ) / 2- (5v-V _TPS2 ) | ≧ 1v
(5) The ignition switch is on.
[0063]
(6) There is no abnormality in the second accelerator position sensor (APS2) 51B and the second throttle position sensor (TPS2) 37B.
(7) An abnormality in communication from the throttle controller 160 to the engine ECU 16 has occurred.
▲ 8 ▼ | (Engine ECU command opening voltage -V _TPS2 ) | ≧ 1v
When it is determined that the throttle controller 160 has failed, limp home processing is performed.
[0064]
F. APS failure
The accelerator position sensor includes first and second APSs 51A and 51B. The first and second accelerator position sensors (APS1 and APS2) 51A and 51B are as follows. Failure due to sensor GND open, failure due to sensor GND open, failure due to (2) current circuit open, failure due to sensor GND short, and (3) characteristic abnormality.
・ A failure caused by a short circuit in the current circuit of the second accelerator position sensor (APS2) 51B or a failure caused by opening the sensor GND causes (1) no communication abnormality and (2) the first accelerator position sensor (APS1) 51A On the premise that the condition that there is no abnormality is satisfied, it is determined if both of the following conditions are satisfied.
[0065]
(1) Output value V of the second accelerator position sensor 51B _APS2 Is equal to or greater than a predetermined value V1 (for example, if V1 = 4.5v, V _APS2 ≧ 4.5v).
(2) Output value V of the first accelerator position sensor 51A _APS1 Is within a predetermined area (for example, 0.2v ≦ V _APS1 ≦ 2.5v).
A failure due to the opening of the current circuit of the second accelerator position sensor (APS2) 51B or a failure due to a short of the sensor GND causes an output value V of the second accelerator position sensor 51B. _APS2 Is less than or equal to a predetermined value V2 (for example, if V2 = 0.2v, V _APS2 <0.2 v).
・ A failure caused by a short circuit in the current circuit of the first accelerator position sensor (APS1) 51A or a failure caused by opening of the sensor GND causes (1) no communication abnormality and (2) the second accelerator position sensor (APS2) 51B. On the premise that the condition that there is no abnormality is satisfied, it is determined if both of the following conditions are satisfied.
[0066]
(1) Output value V of the first accelerator position sensor 51A _APS1 Is equal to or greater than a predetermined value V3 (for example, if V2 = 4.5v, V _APS1 ≧ 4.5v).
(2) Output value V of the second accelerator position sensor 51B _APS2 Is within a predetermined area (for example, 0.2v ≦ V _APS2 ≦ 2.5v).
A failure due to the opening of the current circuit of the first accelerator position sensor (APS1) 51A or a failure due to a short of the sensor GND causes an output value V of the first accelerator position sensor 51A. _APS1 Is a predetermined value V4 or less (for example, if V4 = 0.2 v, V _APS1 <0.2 v).
・ Also, the characteristic of the accelerator position sensor is abnormal if the idle switch is on (ie, during idling). _APS2 Determination is made when ≧ 1.1v.
[0067]
Then, when the second accelerator position sensor 51B fails, the following processing is performed.
▲ 1 ▼ V _APS = V _APS1 Set to / 2.
(2) Lean operation prohibition processing
(3) Cruise control control prohibition process
(4) Engine output upper limit clip processing
However, if a communication abnormality from the throttle controller 160 to the engine ECU 16 occurs after detecting the failure of the second accelerator position sensor (APS2) 51B, a limp home process is performed.
[0068]
Further, when the first accelerator position sensor 51A fails, the following processing is performed.
▲ 1 ▼ V _APS = V _APS2 Set to / 2.
(2) Lean operation prohibition processing
(3) Cruise control control prohibition process
(4) Engine output upper limit clip processing
However, if the second accelerator position sensor (APS2) 51B has already failed, limp home processing is performed.
[0069]
When the accelerator position sensor characteristics are abnormal, the following processing is performed.
▲ 1 ▼ V _APS = V _APS1 Set to / 2.
(2) Lean operation prohibition processing
(3) Cruise control control prohibition process
(4) Engine output upper limit clip processing
However, if the first accelerator position sensor (APS1) 51A has already failed, limp home processing is performed.
[0070]
G. LHV failure
Regarding the failure of the LHV 12, (1) when the LHV solenoid is turned off and (2) the terminal voltage Lo is detected, it is determined that the LHV 12 has failed.
When the LHV 12 fails, the following processing is performed.
(1) Forced compression lean operation.
[0071]
(2) Fuel cut processing at high engine speed (eg Ne ≧ 3000rpm)
(3) Cut the EGR.
(4) Engine speed feedback control for idle speed control is prohibited.
By the way, the limp home process operates the LHV 12 so that air can be supplied to each combustion chamber of the engine. The LHV main body 14 of the LHV 12 is normally on / off controlled to operate the LHV 12. Turns on the LHV main body 14.
[0072]
Therefore, during limp home processing, the intake air amount is not adjusted and the engine output itself is adjusted. Set Instead, the vehicle speed control is set to be performed exclusively by the driver's brake operation.
For this reason, the amount of intake air during operation of the LHV 12 is suppressed so that the engine output is not excessive. In other words, when the LHV 12 is operated, a certain amount of intake air is obtained so that a constant traveling output can be obtained and the driver's braking operation does not interfere with deceleration or stopping.
[0073]
Specifically, the limp home process is performed as follows.
A: Fuel cut processing
1) When traveling forward
(1) The output value of the second accelerator position sensor (APS2) 51B is below a predetermined value [(5v-V _APS2 )> 1.5v], all cylinder fuel injection is performed.
[0074]
(2) The output value of the second accelerator position sensor (APS2) 51B exceeds a predetermined value [(5v-V _APS2 ) ≦ 1.5v], some of the cylinders (for example, 3 cylinders for all 6 cylinders) are cut by fuel injection.
{Circle around (3)} When the second accelerator position sensor (APS2) 51B fails, some cylinders (for example, three cylinders for all six cylinders) are cut off by fuel injection.
[0075]
(4) When the brakes are depressed, some of the cylinders (for example, 3 cylinders for all 6 cylinders) are cut off by fuel injection.
2) During reverse travel
Some cylinders (for example, 3 cylinders for all 6 cylinders) are cut off by fuel injection.
B: Turn off the motor relay.
[0076]
C: LHV12 is turned on [however, when the brake is depressed (when the brake switch is turned on), the LHV12 is duty-controlled at 5 Hz for a predetermined time (for example, 2 seconds).
D: Lean operation is prohibited.
E: Cruise control control prohibition processing
F: The engine speed feedback control is prohibited.
[0077]
G: The warning lamp 180 is turned on.
H: Once the limp home mode is entered, normal operation is not restored until the ignition switch is turned off.
In each fail process, the lean mode is prohibited. However, since the lean mode is a mode that is established based on highly accurate throttle control, there is a risk that stable combustion may be impaired in the lean mode when a TPS failure occurs. In order to avoid this, the lean mode is prohibited.
[0078]
Next, a failure determination process in the case of a position feedback failure due to the sticking of the electronic control throttle valve 15, which is a feature of the vehicle control apparatus according to the present embodiment, will be described.
For this failure determination processing, the throttle controller 160 is provided with a failure determination means 70 as shown in FIG. 1, but it is determined whether or not a failure has occurred due to the electronic control throttle valve 15 being stuck. According to the result of this determination, a process for switching the operation mode is performed.
[0079]
This failure determination means 70 includes First While reading the target opening set based on the detection information from the accelerator position sensor 51A, 2 The opening degree of the electronic control throttle valve 15 detected by the throttle position sensor (TPS2) 37B is read, and the target opening degree is compared with the opening degree of the electronic control throttle valve 15, and at a predetermined time (for example, 500 ms). If a difference in opening over a predetermined opening (for example, 1 °) continues, it is determined that a failure has occurred due to the electronic control throttle valve 15 being stuck.
[0080]
Also, First Although the target opening set based on the detection information from the accelerator position sensor 51A is small, the opening of the electronically controlled throttle valve 15 detected by the second throttle position sensor (TPS2) 37B is When it does not become small (that is, when it remains in a large opening state larger than the first predetermined opening), it is determined that the valve is stuck open, First Although the target opening set based on the detection information from the accelerator position sensor 51A is large, the opening of the electronically controlled throttle valve 15 detected by the second throttle position sensor (TPS2) 37B is When it does not become large (that is, when the small opening is smaller than the second predetermined opening), it is determined that the valve is closed.
[0081]
When the electronic control throttle valve 15 remains at the first predetermined opening or more and it is determined that the valve is stuck open, the above-mentioned sticking handling process (valve open sticking fail process) is performed. When the valve 15 remains at the second predetermined opening or less and it is determined that the valve is closed and closed, a closed sticking handling process (valve closed sticking fail process) is performed.
[0082]
By the way, when a valve failure other than this open fixing (full open fixing) occurs, limp home processing is performed. However, in the limp home processing, as described above, when the accelerator opening is greater than or equal to a predetermined opening, the entire limp home processing is performed. Fuel is injected into the cylinder (all cylinder injection). If the accelerator opening is equal to or less than a predetermined opening, fuel injection in some cylinders is stopped (partial cylinder injection cut).
[0083]
That is, when the accelerator opening is small at the time of valve failure, that is, when the driver does not request engine torque, fuel injection is performed not only in the operation region but also in some cylinders (here, 3 cylinders out of 6 cylinders). If the engine output is reduced and the accelerator opening is large, that is, if the driver requests engine torque, do not stop fuel injection in some cylinders, that is, inject fuel into all cylinders. To ensure engine output. The control function for appropriately stopping the fuel injection and reducing the engine output in this way is called output reduction means (not shown).
[0084]
As described above, this output reduction means always stops fuel injection in some cylinders (here, 3 cylinders out of 6 cylinders) during the reverse operation to reduce the engine output and ensure the engine output during the reverse operation. Can be reduced.
Even when it is determined that no failure has occurred in the failure determination processing in the case of such a position feedback failure relating to the electronically controlled throttle valve 15, the APSs 51A and 51B serving as the accelerator opening detection means have failed. However, in this case, since the intake air amount cannot be adjusted accurately, if the late lean combustion mode included in the lean combustion mode is selected, the combustion becomes unstable and the driver is anxious. It is possible to give a feeling.
[0085]
Therefore, in the control device according to the present embodiment, the failure determination process in the case of an APS failure is performed as described above (see “F. APS failure”).
For such failure determination processing, the throttle controller 160 is provided with an accelerator opening failure determination means (not shown), and it is determined whether or not the APS 51A, 51B has failed by this accelerator opening failure determination means. It comes to judge. If it is determined by the accelerator opening failure determination means that the APS 51A, 51B has failed, the intake air amount cannot be adjusted accurately, so that the opening of the electronically controlled throttle valve 15 is controlled by the DBW. While driving to a predetermined small opening state, the operation mode is switched to the stoichiometric air-fuel ratio mode.
[0086]
Since the vehicle control apparatus according to the embodiment of the present invention is configured as described above, the failure of the intake control system, that is, the failure of the electronic throttle control device (DBW) 150 and the LHV12 system, For example, as shown in FIG. That is, first, a process for determining an LHV failure is performed by an LHV failure determination routine (step A10). The determination of the LHV failure is as follows: (1) Whether the LHV solenoid is OFF and (2) whether the terminal voltage Lo is detected. (1) The LHV solenoid is OFF and the (2) terminal If the voltage Lo is detected, it is determined that there is an LHV failure. In this case, after the determination in step A20, engine output suppression processing is performed in step A30. Specifically, the following processes are performed.
[0087]
(1) Forcibly set the operation mode to the late lean combustion operation mode (compression stroke injection mode) to reduce engine output.
(2) When the engine speed Ne exceeds a predetermined speed (for example, 3000 rpm), the fuel of Cut (stop fuel supply) to reduce engine output.
(3) Cut (stop) EGR and give priority to stable combustion over exhaust gas purification.
[0088]
(4) For idle speed control, prohibit engine revolution feedback control and give priority to stable combustion.
On the other hand, if the LHV failure is not found, the process proceeds to step A40 through the determination in step A20, and the APS fail flag Ffail. ₁ Whether or not is 1 is determined. This APS fail flag Ffail ₁ Is First and second If either of the accelerator position sensors (APS) 51A, 51B fails, the value is 1. Otherwise, it is 0. Here, the flag Ffail ₁ Is 1, the process proceeds to the APS double failure determination routine in step A80, and the flag Ffail ₁ If is not 1, the process proceeds to the APS failure determination routine of step A50.
[0089]
In the APS failure determination routine of step A50, for each of the first accelerator position sensor (APS1) 51A and the second accelerator position sensor (APS2) 51B, (1) failure due to short circuit of the current circuit, failure due to sensor GND open, (2) The above-described determination process is performed for a failure due to an open current circuit, a failure due to a sensor GND short-circuit, and (3) a characteristic abnormality.
[0090]
If an APS failure is determined, the process proceeds to step A80 via step A70, where the APS failure is a double failure, that is, the first and second accelerator position sensors (APS1, APS2) 51A, 51B are both It is determined whether or not a failure has occurred. If the APS is a double failure, the process proceeds to step A300 to perform limp home processing. If the APS is not a double failure, that is, if only one of the two APSs is broken, the process proceeds to step A90.
[0091]
In Step A90, it is determined whether or not the brake switch is on, that is, whether or not a brake operation is being performed. If the brake operation has been performed, the process proceeds to step A100, where the throttle opening command value is clipped to a predetermined upper limit value to suppress the intake air amount, thereby suppressing the engine output. If the brake operation is not performed, the process proceeds to step A120, and each failure process is performed in response to the APS failure.
[0092]
That is, when the second accelerator position sensor 51B fails, (1) V _APS = V _APS1 Set to / 2, (2) prohibit lean operation, (3) prohibit cruise control, and (4) clip the engine output upper limit. However, if a communication abnormality from the throttle controller 160 to the engine ECU 16 occurs after detecting the failure of the second accelerator position sensor (APS2) 51B, a limp home process is performed.
[0093]
When the first accelerator position sensor 51A fails, (1) V _APS = V _APS2 Set to / 2, (2) prohibit lean operation, (3) prohibit cruise control, and (4) clip the engine output upper limit. However, if the second accelerator position sensor (APS2) 51B has already failed, limp home processing is performed.
When the accelerator position sensor characteristics are abnormal, (1) V _APS = V _APS1 Set to / 2, (2) prohibit lean operation, (3) prohibit cruise control, and (4) clip engine output upper limit. However, if the first accelerator position sensor (APS1) 51A has already failed, limp home processing is performed.
[0094]
On the other hand, if there is no APS failure, the process proceeds from step A60 to the ETV determination routine of step A130.
In this ETV determination routine, a failure of the throttle controller is determined. (1) The ignition switch is on, (2) There is no abnormality in the second accelerator position sensor (APS2) and the second throttle position sensor (TPS2), and (3) An abnormality in communication from the engine ECU 16 to the throttle controller 160 occurs. ▲ 4 ▼ | (V _APS2 ) / 2- (5v-V _TPS2 ) | ≧ 1v or (5) The ignition switch is on, (6) There is no abnormality in the second accelerator position sensor (APS2) and the second throttle position sensor (TPS2), and (7) Throttle controller An abnormality in communication from 160 to engine ECU 16 has occurred. {Circle over (8) | (engine ECU command opening voltage -V _TPS2 ) When | ≧ 1v, it is determined that the throttle controller has failed.
[0095]
If it is determined that the throttle controller has failed, the process proceeds to step A300 through step A140. Limp home processing is performed. If it is not determined that the throttle controller has failed, the process proceeds to a communication failure determination routine in step A150.
In this communication failure determination routine, a communication failure from the engine ECU 16 to the throttle controller 160 and a communication failure from the throttle controller 160 to the engine ECU 16 are determined as communication failures.
[0096]
Communication abnormality from the engine ECU 16 to the throttle controller 160 is determined under the condition (1) where the battery voltage Vb is equal to or higher than a predetermined value and (2) communication abnormality from the throttle controller 160 to the engine ECU 16 does not occur. When the throttle controller 160 receives a communication failure signal from the engine ECU 16, it is determined as a failure.
[0097]
Communication abnormality from the throttle controller 160 to the engine ECU 16 is determined under the condition (1) where the battery voltage Vb is equal to or higher than the predetermined value and (2) the cruising switch is off (1). Yes, (2) There is an overrun framing error, and (3) If the communication is incomplete for a predetermined time (for example, for 25 msec), it is determined that there is a failure.
[0098]
If such a communication failure is determined, the process proceeds to step A170 through step A160, and communication failure handling processing is performed.
That is, when there is an abnormality in communication from the engine ECU 16 to the throttle controller 160, there is a high possibility that the intake air amount control cannot be performed properly. Therefore, (1) lean operation is prohibited, (2) cruise control control is prohibited, and (3) At the time of high engine rotation (for example, Ne ≧ 3000 rpm), fuel cut is performed.
[0099]
In addition, when there is a communication error from the throttle controller 160 to the engine ECU 16, there is a high possibility that the intake air amount control cannot be performed properly. (1) A communication failure is transmitted to the throttle controller 160, and (2) lean operation is prohibited. , (3) Prohibit cruise control control, (4) Cut fuel at high engine speed (eg Ne≥3000rpm), (5) Set the throttle valve command target opening from the engine ECU 16 when the brake is depressed Clip the upper limit.
[0100]
If no communication failure is determined, the process proceeds to step A180 through the motor failure determination routine through step A160.
In the motor failure determination routine, (1) the motor relay is on, and (2) the motor output has a ground fault or a power fault when there is no communication abnormality from the throttle controller 160 to the engine ECU 16 (zone). When the signal is received, it is determined that the motor has failed.
[0101]
When this motor failure is determined, the process proceeds to step A300 through step A190, the limp home process is performed, and if the motor failure is not determined, the process proceeds to the TPS failure determination routine of step A200.
In the TPS failure determination routine, (1) when each failure signal is received under the situation (zone) that the ignition switch is on and (2) no communication abnormality from the throttle controller 160 to the engine ECU 16 has occurred. Then, it is determined as a failure. The first throttle position sensor (TPS1) 37A used for feedback control by the throttle controller 160 has (1) failure due to open or short of the current circuit and (2) poor linearity. As for the sensor (TPS2) 37B, there are (3) characteristic abnormality and (4) failure due to open or short of the current circuit.
[0102]
Based on the determination result of such a TPS failure determination routine, it is determined in step A210 whether one of TPS1 and TPS2 has failed. Here, if one of TPS1 and TPS2 has failed, the process proceeds to step A220, and it is determined whether both TPS1 and TPS2 have both failed.
[0103]
If both TPS1 and TPS2 are out of order, the process proceeds to step A300 and limp home processing is performed. Otherwise (ie, only one of TPS1 and TPS2 is out of order), step Proceeding to A230, a lean mode prohibition process is performed. In the lean mode prohibition process, the lean mode is a mode that is established based on highly accurate throttle control. Therefore, when the TPS fails, the lean mode may impair stable combustion. In order to avoid this, the lean mode is prohibited.
[0104]
On the other hand, if none of the throttle position sensors (TPS) has failed, the process proceeds to step S210 to a position feedback failure determination routine (POS F / B failure determination routine) in step S240.
In the position feedback failure judgment routine, position feedback failure, that is, (1) valve system sticking (including fully closed sticking) and (2) motor output open is judged. This judgment is made by (1) ignition switch. Is ON, and (2) the motor relay is ON, or communication abnormality from the engine ECU 16 to the throttle controller 160 has occurred, and (3) the battery voltage Vb is equal to or greater than a predetermined value, and (4) throttle A failure is determined when a position feedback failure signal is received in a situation (zone) where no communication abnormality has occurred from the controller 160 to the engine ECU 16.
[0105]
If a position feedback failure is not determined, the failure process is not performed (returns) through step A250. If a position feedback failure is determined, the process proceeds to step A260 via step A250, and the second throttle valve opening degree is determined. V _TPS2 Is greater than or equal to a predetermined value K1 (K1: a value close to full valve opening). Here, the second throttle valve opening V _TPS2 If the value is equal to or greater than the predetermined value K1, the process proceeds to step A280, and the valve open fixing fail process is performed.
[0106]
In step A260, the second throttle valve opening V _TPS2 Is not greater than or equal to the predetermined value K1, the process proceeds to step A270 where the second throttle valve opening V _TPS2 Is less than or equal to a predetermined value K2 (K2: a value close to the valve fully closed). Here, the second throttle valve opening V _TPS2 If the value is equal to or less than the predetermined value K2, the process proceeds to step A290, where the valve closed fixing fail process is performed.
[0107]
Also, the second throttle valve opening V _TPS2 If the value is between the predetermined values K1 and K2, the process proceeds to step A300 and limp home processing is performed.
Then, the limp home process in step A300 is performed as shown in FIG.
That is, the lean operation mode is prohibited (step B10). That is, the lean operation mode that requires highly accurate throttle control is avoided, and more stable combustion can be performed by the stoichiometric mode or the like.
[0108]
Next, the motor relay (power supply relay) 62 is turned off. As a result, power is not supplied to the throttle controller 160, throttle valve control through the throttle controller 160 is not performed, and only the limp home valve 14 is controlled to adjust the intake air amount.
Then, it is determined whether or not the brake switch is on, that is, whether or not a brake operation is being performed (step B30). If the brake switch is on, the limp home valve (LHV) 14 is duty-controlled for a predetermined time (for example, 2 seconds) (step B40).
[0109]
In other words, the limp home valve 14 is an on / off valve that is normally set to either on or off, but is an electromagnetic valve, and therefore duty control is possible. Here, for example, the LHV 14 has a duty of about 50%. The amount of air flowing through the bypass passage 13 can be reduced by suppressing the opening degree of the valve, whereby the negative pressure of the intake manifold 9 can be increased and the master back negative pressure can be secured. Yes. Therefore, even during limp home processing, a sufficient master back negative pressure can be obtained at the time of brake operation, and a braking force similar to that during normal operation can be ensured.
[0110]
In addition, a predetermined time (two seconds here) at the start of the brake operation is sufficient for such processing, and the duty control ends when the predetermined time elapses. In addition, durability of a solenoid is also ensured by restrict | limiting duty control of this limp home valve 14 within predetermined time.
On the other hand, if the brake switch is off, the limp home valve (LHV) 14 is turned on (opened) (step B50).
[0111]
And if the process of step B40, B50 is performed, it will progress to step B60 and it will be determined whether the vehicle is moving forward.
If the vehicle is not moving forward, it means that the vehicle is moving backward, and fuel cut of some cylinders is always performed (for example, 3 of the 6 cylinders are fuel cut) to suppress engine output (step B110). ). Thereby, it is possible to prevent the engine output from becoming excessive at the time of parking and entering the garage due to reverse running.
[0112]
If the vehicle is moving forward, the process proceeds to step B70, and whether or not the output value of the second accelerator position sensor (APS2) 51B is equal to or greater than a predetermined value [(5v-V _APS2 )> 1.5v or (5v-V _APS2 ) ≦ 1.5 v] is determined.
Where (5v-V _APS2 ) ≦ 1.5v, the process proceeds to step B110, where fuel cut is performed on some cylinders (for example, 3 of the 6 cylinders are fuel cut) to suppress engine output. In addition, (5v-V _APS2 )> 1.5v, the process proceeds to step B80 to determine whether or not the second accelerator position sensor (APS2) 51B is out of order. This failure determination is performed as described above.
[0113]
If APS2 is out of order, the process proceeds to step B110, where fuel cuts are performed on some cylinders (for example, three of the six cylinders are fuel cut) to suppress engine output. If the APS 2 has not failed, the process proceeds to step B90, and it is determined whether or not the brake switch is on, that is, whether or not the brake operation is being performed.
Here, if the brake switch is on, a fuel cut of a part of the cylinders (for example, a fuel cut of three of the six cylinders) is performed to suppress the engine output. If the brake switch is not on, the process proceeds to step B100, fuel is injected in all cylinders, and the output is secured.
[0114]
Further, during the limp home process, the warning lamp 180 is also turned on.
In this way, the limp home process is in forward travel, there is no APS2 failure (that is, the driver's speed request intention can be grasped from the APS2 information), the brake operation is not performed, and the accelerator opening is predetermined. If it is greater than the value, that is, when the driver is requesting engine output, fuel cut is not performed, but when traveling backward, when the APS2 fails, when the brake is operated, or when the accelerator opening is less than the predetermined value As a safety-side control, a fuel cut of a part of the cylinders (for example, 3 of the 6 cylinders is cut) is performed to suppress the engine output.
[0115]
The driver can obtain the vehicle speed if the brake is not operated, and can be decelerated and stopped if the brake is operated. Even when the intake system is broken, the remaining driver intention reflecting means is brake operation information. Based on this, the vehicle speed control reflecting the driver's intention can be performed at a certain level.
Next, processing at the time of valve failure, which is a feature of the control device according to the present embodiment, will be described.
[0116]
In the valve open fixing fail process (step A280 in FIG. 4), (1) the LHV 12 is turned off (closed) to limit the intake air amount, and (2) the fuel injection mode is limited to the compression lean mode (forced compression lean mode). Mode), (3) fuel supply to some cylinders (for example, 3 cylinders for a 6-cylinder engine) is stopped (partial cylinder fuel cut), (4) EGR control is stopped (EGR cut), and (5) ▼ If the engine speed Ne is within a predetermined high speed range (Ne ≧ 3000 rpm), the fuel supply is stopped (fuel cut) for all cylinders. ⑥ Among the auxiliary machines driven by the engine, the engine is activated by stopping. Those that do not have an adverse effect are stopped (here, the air conditioner is stopped).
[0117]
As described above, in the present control device, when the throttle valve 15 is stuck in a large opening state equal to or larger than the predetermined opening, the late lean combustion operation mode is selected or the fuel injection of a predetermined number of cylinders is stopped. The output of the engine is reliably reduced, and the situation where the output is excessively output even though the driver's output is not requested is surely avoided, and the driver's request is stabilized. There is an advantage that traveling can be secured.
[0118]
Furthermore, when it is determined that the throttle valve 15 is stuck in a large opening state greater than or equal to a predetermined opening degree, by reducing the load on the engine auxiliary equipment, the combustion in the lean combustion mode is stabilized, There is also an advantage that stable driving can be ensured while preventing the driver from feeling uneasy due to output fluctuation.
Further, for other valve failures (including when the valve is stuck closed), the limp home process as described above is performed in order to secure intake using the LHV 12.
[0119]
In the limp home process, from the viewpoint of valve failure, during forward travel, if the accelerator opening is greater than or equal to the predetermined opening, fuel is injected into all cylinders (all cylinder injection), and if the accelerator opening is less than the predetermined opening, some cylinders Is stopped (partial cylinder injection cut).
As a result, when the driver does not request engine torque, fuel injection in some cylinders (here, 3 cylinders out of 6 cylinders) is stopped to reduce engine output, and when the driver requests engine torque. The driver's intention to request the output can be reflected in the engine output without stopping the fuel injection of some cylinders, that is, by ensuring the engine output by injecting the fuel into all the cylinders.
[0120]
Further, at the time of reverse operation, the fuel injection of some cylinders (here, 3 cylinders out of 6 cylinders) is always stopped to reduce the engine output, and the engine output at the time of reverse operation can be surely reduced. This makes it possible to easily perform the driving operation during the reverse operation. That is, the drivability of the reverse operation can be improved.
[0121]
Note that when it is determined that the throttle valve 15 is stuck in a small opening state equal to or less than a predetermined opening, the lean combustion mode is prohibited, so that the engine output is secured and the driver output is requested. However, there is also an advantage that a stable driving according to the driver's request can be ensured by avoiding a state in which no output is output despite being.
Even if the failure determination means 70 does not determine the failure of the electronic throttle control device, if the accelerator opening detection means determines that the accelerator opening detection means has failed, the throttle valve opening is predetermined. Therefore, the lean combustion mode is prohibited from being selected, so that the combustion is stable, and there is an advantage that stable driving can be ensured without giving anxiety to the driver.
[0122]
In the control device of this embodiment, when it is determined that the valve is stuck open, an open sticking handling process (valve open sticking fail process) is performed, whereas when it is judged that the valve is stuck closed, a closing sticking handling process (valve closed sticking fail) is performed. However, only one of the processes may be performed.
Also, in this control device, fuel supply is stopped for some cylinders (fuel cut) to reduce output. The However, if combustion is established, the fuel supply may be stopped instead of the fuel supply stop.
[0123]
In the present control device, the compression stroke injection mode included in the lean combustion mode is switched. However, in an engine having only the intake stroke injection mode (preliminary lean combustion operation mode) included in the lean combustion mode, A process of switching to the intake stroke injection mode may be performed.
Further, in this control device, two accelerator position sensors are provided as accelerator opening detection means. However, even in a device having only one accelerator position sensor as the accelerator opening detection means, electronic throttle control is also possible. In the case where the device is not broken and the accelerator position sensor is broken, as a failure handling process, the electronically controlled throttle valve is set to a predetermined small opening state, and the lean combustion mode (particularly, A process of prohibiting the compression stroke injection mode) may be performed.
[0124]
The reset condition for fail judgment is briefly described. The reset condition includes ignition key OFF, battery OFF, etc. The above control is repeated at the time of the most travel, and normal control is performed when DBW is normal at the time of redetermination. Return to. In this case, if the fail content is stored in the computer (ECU or controller) as fail information, the DBW system can be rechecked during vehicle inspection.
[0125]
The present control device is described as a control device provided in a direct injection internal combustion engine, but is not limited to this, and the control device for an internal combustion engine capable of selecting a lean combustion mode and a stoichiometric air-fuel ratio mode. It can also be applied.
In the present embodiment, the control device uses an automatic transmission as a transmission, but it can be applied to a manual transmission.
[0126]
【The invention's effect】
As described in detail above, according to the vehicle control device of the present invention, when the electronic throttle control device is out of order, Withdrawal Since the engine output is reduced when traveling forward than when traveling forward, the engine output does not become excessive when traveling backward, and there is an advantage that drivability during backward traveling is improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a main part of a control device for a direct injection internal combustion engine according to a control device for a vehicle as an embodiment of the present invention.
FIG. 2 is a block diagram showing a control device for a direct injection internal combustion engine according to a control device for a vehicle as one embodiment of the present invention.
FIG. 3 is a block diagram showing an intake control system of a direct injection internal combustion engine according to the vehicle control apparatus as one embodiment of the present invention.
FIG. 4 is a flowchart showing a failure countermeasure process of the intake control system of the direct injection internal combustion engine according to the vehicle control apparatus as one embodiment of the present invention.
FIG. 5 is a flowchart showing a limp home process in an anti-failure process of an intake control system of a direct injection internal combustion engine according to a control apparatus for a vehicle as an embodiment of the present invention.
[Explanation of symbols]
1 Engine body
2 Intake passage
2A Intake port
3 Throttle valve installation part
4 Air cleaner
5 Throttle body
5A Intake passage in throttle body
7 Intake pipe
8 Surge tank
9 Intake manifold
12 Limp home valve device (LHV)
13 Bypass passage
14 Limp Home Valve
15 Electronically controlled throttle valve (throttle valve)
16 Engine control computer (engine ECU)
16A Target opening setting part
17 Exhaust passage
17A Exhaust port
18 Combustion chamber
19 Intake valve
20 Exhaust valve
21 Fuel injector (injector)
22 Fuel tank
23A-23E Fuel supply path
24 Low pressure fuel pump
25 High pressure fuel pump
26 Low pressure regulator
27 High pressure regulator
28 Delivery Pipe
29 Exhaust gas recirculation passage (EGR passage)
30 EGR valve (exhaust gas amount adjusting means)
32 Flow path for reducing blow-by gas
33 Valve for positive ventilation in the crankcase
34 Canister
35 Exhaust gas purification catalyst
36 Intake air temperature sensor
37A First throttle position sensor (TPS1)
37B Second throttle position sensor (TPS2)
38 Idle switch
40 First cylinder detection sensor
41 Crank angle sensor
42 Water temperature sensor
43 O ₂ Sensor
50 accelerator pedal
70 Failure determination means (failure detection means)
51A First accelerator position sensor (APS1)
51B Second accelerator position sensor (APS2)
120 Limp Home Valve Control Device
150 Electronic throttle control device [Drive-by-wire (DBW)]
151 Butterfly valve
152 Shaft supporting butterfly valve
153 Return spring
154 Electric motor (throttle actuator)
155 Gear mechanism
160 Throttle control computer (throttle controller)
160A Throttle opening feedback control unit
170 Automatic transmission (AT)
171 Automatic transmission controller (AT controller)
180 Warning light

Claims (1)

A vehicle control device comprising an engine having an electronic throttle control device for electrically driving a throttle valve, and a transmission connected to the output shaft of the engine,
It detects that the electronic throttle control device is malfunctioning , and malfunctions due to a closed valve that adheres the throttle valve at a predetermined opening or less from a malfunction signal and the opening information of the throttle valve. Fault detection means capable of detecting
Accelerator opening detection means for detecting the accelerator opening of the engine;
It is installed so that air can be supplied to each combustion chamber of the engine when it is determined by the failure detection means that the throttle valve is closed and fixed , and on / off control is performed without adjusting the intake air amount. Limp home valve,
Zona example an output reduction means for reducing the output of the engine by controlling to stop the fuel supply to a given cylinder of the engine,
Output reduction means when it is detected that the valve closed sticking wear of the throttle valve by the failure detecting means, when the forward gear is selected by the speed-change machine, detected by the accelerator opening detection means conditions reduced the output of the engine to the accelerator opening is equal to or less than a predetermined opening degree, when the reverse gear in the speed change device is selected, Turkey accordance with a detection result of the accelerator opening detection means and without, characterized in that reducing the output of the engine to normal, the vehicle control apparatus.

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