JP2987269B2 - Vehicle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vehicle having a constant speed traveling control function.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing an example of a conventional constant speed traveling control device. In the figure, reference numeral 2 denotes an intake pipe of an internal combustion engine of a vehicle, and a throttle valve 11 installed therein.
The adjustment of the intake air amount is performed according to the above. By transmitting the operation of the accelerator pedal 41 or the vacuum actuator 15 to the throttle link 19 via the pulley 14, the throttle valve 11 is driven to the open side (the intake air amount is large). If there is no operation by the accelerator pedal 41 and the vacuum actuator 15 is the throttle valve 11 is full <br/> closed side by a return spring 12 (the intake air amount is minimum) is returned to. In addition, when the accelerator pedal 41 and the vacuum actuator 15 both open the throttle valve 11 at the same time, the pulley 14 transmits a larger operation amount as an operation of the throttle link 19.

The constant-speed running control is performed by operating a throttle valve 11 using a vacuum actuator 15. Hereinafter, the configuration of the constant speed traveling control section will be described. The vacuum pump 18 generates a negative pressure as a power source for driving the vacuum actuator 15. The negative pressure generated by the vacuum pump 18 is adjusted by the control valve 16. The opening valve 17 sets the vacuum system 15 to all atmospheric pressures,
To stop the driving of the motor. The vacuum pump 18, the control valve 16 and the release valve 17 are connected to a constant speed control unit (hereinafter referred to as “ACC”) 7.
The throttle valve 11 is controlled by driving or opening the vehicle based on the vehicle speed information from the vehicle speed sensor 3.

The ACC 7 includes a set switch 51 for instructing the start of the constant-speed running control, a return switch 52 for instructing a restart of the constant-speed running control at the set vehicle speed stored in the ACC 7, and a constant-speed running control. Switches, such as a release switch 53 for instructing the stop of the operation, and a brake switch 54 that is linked with the brake and releases the constant speed traveling control when the brake is operated.

Next, the operation of the ACC 7 will be described with reference to FIG. First, in step S31, it is determined whether or not start of constant-speed traveling control has been instructed by the set switch 51. If there is an instruction, the actual vehicle speed detected by the vehicle speed sensor 3 is stored as the target vehicle speed in step S32. Next, in step S33, a vacuum pump drive time shown in FIG. 11B for obtaining the required throttle valve opening corresponding to the target vehicle speed shown in FIG.
As shown in FIG. 2, the vacuum pump 18 is driven by supplying an initial pulse to set an initial throttle opening.

Next, in step S34, according to the deviation between the target vehicle speed and the actual vehicle speed detected by the vehicle speed sensor 3 after the output of the initial pulse, as shown in FIG.
, Or by intermittently opening the control valve 16 to correct the throttle opening. Next, a feedback pulse is supplied to the vacuum pump 18 as shown in FIG. 12 so that the actual vehicle speed detected by the vehicle speed sensor 3 becomes the target vehicle speed in step S35, or the control valve 16 is intermittently driven. And the throttle opening is feedback controlled.
A known control technique such as PID control is used for this feedback control.

Next, a failure determination is made in step S36. That is, it is determined whether the vehicle speed control cannot be performed due to a failure of the throttle valve drive system or the like. If the vehicle speed cannot be controlled, the control valve 16 and the release valve 17 are determined in step S37.
Is opened and the throttle valve 11 is closed by the return spring 12 to ensure the safety of the vehicle. Step S
If the vehicle speed control is not impossible at 36, it is determined at step S38 whether or not the control is released. That is, when the brake operation is detected by the brake switch 54 or when the release of the control is instructed by the release switch 53, it is determined that the control is released. When it is not determined that the control is released, the process returns to step S35 to continue the feedback control. When it is determined that the control is released, the control valve 16 and the release valve 17 are opened in step S39, the throttle valve 11 is closed by the return spring 12, and the process returns to step S1 to wait for the next control start instruction.

[0008]

The conventional constant speed cruise control device is configured as described above. When the constant speed cruise control is released, the vacuum actuator is controlled by the control valve 16 and the release valve 17 in two systems. Release the negative pressure of 15,
By the action of the return spring 12, the throttle valve 11
Is closed, the vacuum actuator 15 or
Although the opening failure of the throttle valve 11 due to the failure of the control valve 16 and the opening valve 17 is unlikely to occur, the rotation shaft of the throttle valve 11 or the throttle link 19
If the drive system such as is trapped or foreign matter is caught, the throttle valve 11 will not return to the closed side,
Unintentional rise in engine speed of the driver causes difficulty in driving the vehicle, especially if this condition continues, it may cause runaway of the vehicle and is extremely dangerous for driving the vehicle And so on.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. When the throttle valve control becomes impossible during the constant-speed running control, an excessively high engine speed contrary to the driver's will is required. An object of the present invention is to provide a vehicular control device that can prevent the vehicle from rising and secure a limp home function of the vehicle.

[0010]

A vehicle control device according to the present invention includes an accelerator position sensor for detecting an opening of an accelerator pedal and a throttle valve provided in an intake pipe for supplying air to an engine. A throttle position sensor for detecting, a vehicle speed sensor for detecting the vehicle speed,
First control means for controlling the opening of the throttle valve based on the output of the vehicle speed sensor so that the vehicle speed becomes the target vehicle speed and outputting a fail signal when the throttle valve cannot be controlled; an accelerator position sensor and a throttle; Cylinder control related to position sensor output
And a second control means for performing a partial cylinder deactivation control of the engine based on the cylinder deactivation control map, wherein when the first control means outputs a fail signal, the second control means is provided. In this case, the engine is output controlled by performing partial cylinder rest control. Further, the second control means controls the cooling of the engine.
Fail-cut map related to cooling water temperature and engine speed
And usually fail according to the engine coolant temperature.
Change the number of rotations to cut the fail cut at low temperatures.
The rotational speed is set higher.

[0011]

According to the present invention, when the throttle valve cannot be controlled during the cruise control, the engine output can be controlled by the partial cylinder deactivation control of the engine in accordance with the accelerator opening. In addition to preventing an excessive increase in the engine speed, it is possible to secure the limp home function of the vehicle by operating the accelerator in the same manner as during normal operation.

[0012]

【Example】

Embodiment 1 FIG. Hereinafter, an embodiment of a vehicle control device according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a constant speed traveling control device. In FIG. 1, portions corresponding to those in FIG. 9 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, reference numeral 63 denotes a case where the vehicle speed control becomes impossible due to a failure of the throttle valve drive system during the constant speed traveling control by the ACC (constant speed traveling control unit) 7.
This is a fail signal output from ACC7. The fail signal 63 is supplied to an engine control unit of an engine control device described later.

Reference numeral 21 denotes a throttle position sensor (hereinafter referred to as "TP") for detecting the opening of the throttle valve 11.
S ”), 61 is an accelerator opening (accelerator pedal 4
An accelerator position sensor (hereinafter, referred to as "APS") 62 detects an air flow sensor (hereinafter, referred to as "AFS") that measures the amount of air drawn into an engine (not shown) through the intake pipe 2. It is. These sensors 21, 61, and 62 are components of an engine control device described later, and supply their respective outputs to an engine control unit of the engine control device described later. FIG.
Is configured as described above, and the other configuration is the same as the example of FIG.

FIG. 2 is a block diagram showing the engine control device. This example is a configuration example applied to a vehicle equipped with a six-cylinder engine and an automatic transmission. The engine control device uses the T
PS21, APS61, AFS62, a crank angle sensor 82 for detecting a position of an engine crankshaft and an engine speed, and an inhibitor switch 80 for determining a shift position (N, P range) of the automatic transmission.
And a water temperature sensor 81 for detecting a cooling water temperature, and injectors 84 to 89 for # 1 to # 6 for supplying fuel to each cylinder.
And an igniter 83 that energizes and shuts off ignition coils 90 to 95 of # 1 to # 6 to ignite ignition plugs 96 to 101, and an engine control unit that performs fuel and ignition control corresponding to each sensor input ( Hereinafter, it is referred to as “ECU”.

The operation of the constant speed traveling control device of the example of FIG. 1 will be described with reference to the flowchart of FIG. Step S
The processes from 31 to S39 are exactly the same as the processes in the flowchart in FIG. In the example of FIG. 1, following the fail process of step S37, the process proceeds to step 40 to perform the fail process. The fail process in step 40 is a process for generating a fail signal 63. That is, when the vehicle speed control becomes impossible due to a failure of the throttle valve drive system during the constant speed traveling control, the failure signal 63 is output,
It is supplied to the ECU 8 of the engine control device.

The ECU 8 normally measures the amount of air taken into the engine by the AFS 62, and outputs the crank angle sensor 82
The fuel is supplied by driving the injectors 84 to 89 for each cylinder based on the engine speed and the crank angle measured in the above, and the igniter 83, the ignition coil 90 to
95, the ignition plugs 96 to 101 perform ignition control of each cylinder. When the failure control of the throttle valve 11 is notified by the above-mentioned fail signal 63,
The ECU 8 controls the output of the engine by performing fuel cut of some of the cylinders according to the outputs of the APS 61 and the TPS 21. Hereinafter, the limp home function by this control will be described.

When the throttle valve cannot be controlled, the control valve 16 and the release valve 17 are opened.
Is stopped, and the throttle valve 11 is returned to the fully closed direction by the return spring 12. However, at this time, if a mechanical lock failure of the rotation shaft of the throttle valve 11 or a catch of the throttle link 19 has occurred, the throttle valve 11
Is fixed at the opening when the failure occurs.

When the throttle valve cannot be controlled, the ECU
8 determines that a failure has occurred based on the fail signal 63,
Only when the throttle opening detected in S21 is larger than the predetermined value, the cylinder closing control is performed according to the map shown in FIG. In the cylinder closed according to FIG.
If 1 fails due to full opening, the cylinder output can be varied between the cylinder rest levels 5 to 3 by the detected value of the APS 61, so that the engine output can be adjusted by the operation amount of the accelerator pedal 41. FIG.
(B) shows an example of the cylinder rest level. In the example of FIG. 3B, when the cylinder stall level is the same, a specific cylinder is ceased. However, in practice, the number of cylinders ceased is kept constant and the cylinders are changed to change the cylinders between cylinders. Reduce variation.

While the above-described partial cylinder rest can control the engine output during traveling, fluctuations in idle rotation due to cylinder deactivation and a shift shock due to an increase in engine speed during gear shifting (shifting by shift levers such as P → N, N → D) can occur. Because it occurs
By using the inhibitor switch 80, the fuel control different from that during the traveling is performed in the P and N ranges. Hereinafter, the fuel injection control in the P and N ranges will be described.

The cylinder-stop control when the shift position is in the N or P range uses a cylinder-stop map shown in FIG. In the cylinder rest map, the cylinder is not set to be closed in the low opening range of the throttle valve 11. In addition, even if the cylinders are closed according to this map, the engine speed remains between 2000 and 3000.
rpm (R or D
Shifting to the range causes a large shock and causes poor driving performance), and all-cylinder fuel cut is performed using the fuel cut map shown in FIG. The reason why the fuel cut speed is changed by the water temperature is to cope with an increase in friction loss inside the engine at a low temperature and to improve the drivability at the time of a limp home.

Next, a control flow of the ECU 8 for realizing the above-described limp home function will be described. Figure 5 shows the EC
It is a flowchart which shows the process of the main routine of the control microcomputer not shown inside U8. First, the internal initialization is performed immediately after the power is turned on (step S
1). Next, fuel injection and fuel ignition control are performed (step S
2) Control other engine auxiliary devices such as an idle speed control valve (not shown) (step S3).

Next, it is determined whether or not a throttle failure has occurred (step S4). When the failure signal 63 is supplied from the ACC 7, it is determined that a throttle failure has occurred. If it is not a throttle failure, the processing of steps S2 and S3 is performed. If it is a throttle failure, it is determined whether or not the throttle opening is equal to or less than a predetermined value (step S).
5). If the throttle opening is equal to or less than the predetermined value, the processing of steps S2 and S3 is performed as in the normal state. If the throttle opening is larger than the predetermined value, the fuel cut engine speed is calculated and the cylinder rest level is determined (step S).
6).

When the automatic transmission is in the N and P ranges, the value obtained from the map shown in FIG. 3C is used as the fuel cut rotation speed, and when the automatic transmission is not in the N and P ranges, for example, 4000 rpm is fixed to prevent overrun. And Also, cylinder stop control is performed when the automatic transmission is in the N or P range.
Two values are used: a value obtained from the map shown in FIG. 4A and a value obtained from the map shown in FIG.

Next, the shift position is determined (step S7). Steps S8 and S14 are performed for the N and P ranges and other than the N and P ranges, respectively.
The following processing is performed. In cases other than the N and P ranges, the cylinder rest level obtained from the map of FIG. 4 is set as a cylinder rest instruction (step S8). The execution of the cylinder stop and the fuel cut will be described later with reference to FIG.

Next, it is determined whether or not fuel cut is being executed (step S9). If the fuel cut is being executed, it is determined that the fuel cut is to be canceled (step S12). If it is not higher than the fuel cut release rotation speed, the fuel cut command is released (step S13). The fuel cut release rotation speed is 3900r, which is lower than the fuel cut rotation speed of 4000rpm.
A hysteresis of 100 rpm is provided as pm.
When the fuel cut is not being executed, the execution of the fuel cut is determined (step S10). When the fuel cut speed is 4000 rpm or more,
Set fuel cut command (step S1)
1). When a series of determinations and processes subsequent to step S8 are completed, the process returns to step S2 to execute the following various processes.

If it is determined in step S7 that the engine is in the N or P range, a cylinder stop command is set according to the cylinder stop map shown in FIG. 3A (step S14), and it is determined whether or not fuel cut is being executed. (Step S1
5). If it is being executed, it is determined that fuel cut is to be canceled (step S17), and if it is not being executed, it is determined that fuel cut is to be executed (step S16).

The fuel cut release determination and execution determination use the engine speed corresponding to the water temperature in FIG. 3 (c). In this case, the engine speed for the release determination and the execution determination has a hysteresis of 100 rpm. The setting of the fuel cut command and the release command is performed in step S11.
And S13. When a series of determinations and processes subsequent to step S14 are completed, the process returns to step S2 to execute the following various processes.

Next, the execution of fuel cut will be described with reference to FIG. In the case of the cylinder injection as in the present embodiment, generally, as shown in FIG. 7A, the fuel injection is performed based on the crank angle signal of the crank angle sensor 82 before the intake process of each cylinder. Inject fuel every time. This fuel injection pulse is generated using interrupt processing of a microcomputer inside the ECU 8 every time the crank angle signal rises in FIG.

FIG. 6 is a flowchart of the above-described interrupt processing. First, cylinder determination is performed (step S2).
1). The cylinder discrimination is detected by performing the level judgment of the cylinder discrimination sensor at the time of the rise of the crank angle signal shown in FIG. Next, it is determined whether or not a throttle failure has occurred (step S22). If it is during a throttle failure, it is determined whether or not there is a fuel cut command in FIG. 5 (step S23). If there is a fuel cut command, the interrupt flag is cleared and the interrupt processing ends (step S26).

In step S23, when there is no fuel cut command, it is determined whether or not the cylinder number of the cylinder deactivated by the cylinder deactivation instruction is equal to the current crank angle (cylinder number #n before the suction process) (step S23). S24). If they are the same, the interrupt flag is cleared and the interrupt processing ends (step S26). On the other hand, if they are not the same, after driving the injector of #n (step S25), the interrupt flag is cleared and the interrupt processing is ended (step S26).

If the throttle failure has not occurred in step S22, the injector #n is driven (step S25), and then the interrupt flag is cleared and the interrupt process is terminated (step S26). An off timer is set so that the driving of the injector #n is stopped after a predetermined time from the start of driving of the injector #n (for example, a free-run timer built in a microcomputer and an output compare function are used).

Based on the flowcharts shown in FIG. 5 and FIG.
Fig. 7 (b) shows an example of the fuel injection timing when
Is shown in

Embodiment 2 FIG. In the above-described embodiment, the present invention is applied to a six-cylinder low-voltage power distribution vehicle. However, the present invention can be applied to a high-voltage power distribution vehicle, or an eight- or twelve-cylinder power vehicle. Further, although the constant speed traveling control device of the above-described embodiment uses the vacuum type throttle actuator 15, it can be applied to a system in which the throttle link 19 is directly operated by a DC motor.

[0034]

As described above, according to the present invention, the accelerator position sensor for detecting the opening of the accelerator pedal and the throttle position for detecting the opening of the throttle valve provided in the intake pipe for supplying air to the engine. A vehicle speed sensor that detects a vehicle speed, and a throttle valve that controls the opening of the throttle valve based on the output of the vehicle speed sensor so that the vehicle speed reaches the target vehicle speed, and outputs a fail signal when the throttle valve cannot be controlled. 1 control means, and a cylinder closing control map related to outputs of an accelerator position sensor and a throttle position sensor .
Second control means for performing partial cylinder deactivation control of the engine based on the cylinder deactivation control map, wherein when the first control means outputs a fail signal, the second control means controls the partial cylinder deactivation control. To control the output of the engine.
If the throttle valve cannot be controlled during cruise control, the engine output can be controlled by controlling the partial cylinder deactivation of the engine according to the accelerator opening, resulting in an excessive increase in engine speed contrary to the driver's will. And the limp home function of the vehicle can be secured by the same accelerator operation as during normal operation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a constant speed traveling control device in an embodiment of a vehicle control device according to the present invention.

FIG. 2 is a block diagram showing an engine control device in one embodiment of the vehicle control device according to the present invention.

FIG. 3 is a diagram showing a cylinder-stop control map in the P and N ranges, a relationship between the cylinder-stop level and the cylinder-inactive cylinder, and a fuel cut control map in the N and P ranges.

FIG. 4 is a diagram showing a cylinder stop control map other than in the P and N ranges.

FIG. 5 is a flowchart showing a control operation (main routine) of the engine control device.

FIG. 6 shows a control operation of the engine control device (interrupt processing).
It is a flowchart which shows.

FIG. 7 is a time chart showing a fuel injection operation in a normal state and a throttle failure.

FIG. 8 is a flowchart showing a control operation of the constant speed traveling control device.

FIG. 9 is a block diagram showing a conventional constant speed traveling control device.

FIG. 10 is a flowchart showing a control operation of a conventional constant speed traveling control device.

FIG. 11 is a diagram showing a relationship between a vehicle speed and a required throttle valve opening, and a relationship between a set vehicle speed and a vacuum pump driving time used in a conventional constant speed traveling control device.

FIG. 12 is a time chart illustrating an example of control of a conventional constant-speed traveling control device.

[Explanation of symbols]

 2 Intake pipe 7 Constant speed traveling control unit 8 Engine control unit 11 Throttle valve 12 Return spring 14 Pulley 15 Vacuum actuator 16 Control valve 17 Open valve 18 Vacuum pump 19 Throttle link 21 Throttle position sensor 41 Accelerator pedal 51 Set switch 52 Return switch 53 Release switch 54 Brake switch 61 Accelerator position sensor 62 Air flow sensor 63 Fail signal 80 Inhibitor switch 82 Crank angle sensor 83 Igniter 84-89 Injector 90-95 Ignition coil 96-101 Spark plug

Claims (2)

(57) [Claims] 1. An accelerator position sensor for detecting an opening of an accelerator pedal, a throttle position sensor for detecting an opening of a throttle valve provided in an intake pipe for supplying air to an engine, and a vehicle speed sensor for detecting a vehicle speed. First control means for controlling the opening of the throttle valve based on the output of the vehicle speed sensor so that the vehicle speed becomes the target vehicle speed, and outputting a fail signal when the throttle valve cannot be controlled; It has a cylinder rest control map related to the output of the position sensor and the throttle position sensor.
And second control means for performing a partial cylinder deactivation control of the engine based on the cylinder deactivation control map, wherein when the first control means outputs a fail signal, the second control means And a control unit for controlling the output of the engine by performing the partial cylinder rest control. 2. The engine according to claim 1, wherein said second control means includes means for cooling the engine.
Fail cut map related to water temperature and engine speed
Which usually has a fail
Change the rotation speed of the motor,
Claims characterized in that the number of turns is set higher.
Item 4. The vehicle control device according to Item 1 .