JPH01249532A - Vehicle control device - Google Patents

Abstract

PURPOSE:To appropriately control a vehicle by stopping the operation of a constant speed running device while restraining the output power of an internal combustion engine when the vehicle speed is below a predetermined value with no depression of an accelerator pedal while the load exceeds a predetermined value. CONSTITUTION:A constant speed running device 100 feed-back controls the opening degree of a throttle valve in an internal combustion engine 101 so as to make the actual speed of a vehicle coincident with a desired vehicle speed, and accordingly, the vehicle runs automatically and constantly at the desired speed. In this arrangement, various detecting means 102 through 104 detect a vehicle speed, a degree of depression of an accelerator pedal and a load of the internal combustion engine. A control means 105 stops the operation of the constant speed running device 100 and restrains the output power of the internal combustion engine 101 when such a condition that the vehicle speed is below a predetermined value with no depression of the accelerator pedal while the load exceeds a predetermined value is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device for a vehicle equipped with a so-called constant speed traveling device that automatically causes the vehicle to travel at a constant speed.

[Prior art]

BACKGROUND ART Conventionally, various so-called constant speed traveling devices that automatically make a vehicle travel at a constant speed have been developed (for example, as described in US Pat. No. 3,070,185).

In vehicles equipped with such constant-speed driving devices, the opening of the throttle valve is automatically adjusted when the driver operates a switch or the like to set the desired constant-speed driving, for example on a highway. The vehicle can be driven continuously at a desired constant speed, which is extremely convenient as the driver does not have to constantly press the accelerator pedal.

[Problem to be solved by the invention]

However, in the conventional vehicle control device as described above, depending on the state of the control device, there may be cases where the vehicle does not travel at a desired target speed, for example, the actual traveling speed may become lower than the target speed.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a vehicle control device that can perform more appropriate control depending on the state of the control device.

[Means to solve the problem]

FIG. 1 is a block diagram showing the functionality of the present invention.

In FIG. 1, 100 is a known constant speed traveling device,
For example, the part consisting of 1 to 18 in FIGS. 2 and 3 described later controls the opening degree of the throttle valve of the internal combustion engine 101 so as to eliminate the deviation between the actual vehicle speed and the specified target vehicle speed. This device automatically causes the vehicle to run at a specified constant speed.

Further, toi is an internal combustion engine, and includes a fuel injection control device, an ignition timing control device, and the like.

Further, 102 is a vehicle speed detection means for detecting the vehicle speed, and corresponds to, for example, the vehicle speed sensor 24 in FIG. 2, which will be described later. Further, 103 is an accelerator pedal detection means for detecting whether or not the accelerator pedal is depressed, and corresponds to, for example, the accelerator pedal sensor 25 in FIG. 2, which will be described later.

Further, 104 is a load detection means for detecting the load amount of the internal combustion engine, for example.

This corresponds to the load sensor 26 in FIG. 2, which will be described later. Note that the throttle valve opening of the internal combustion engine, the amount of intake air, etc. can be used as the load amount.

In addition, when the vehicle speed is below a predetermined value and the accelerator pedal is not depressed, but the load amount is above a predetermined value, the control means 105 controls the constant speed traveling device 105.
At the same time as stopping the operation of the internal combustion engine r! This control is performed to limit the output of A101. This control means 10
4 corresponds to, for example, the control means 22 and the switching means 21 in FIG. 2, which will be described later.

As a method for stopping the operation of the constant speed traveling device 100 as described above, for example, as shown in FIG. A method may be used in which the connection point X with the control unit 13 is cut off or grounded.

Further, as a method for limiting the output of the internal combustion engine 101 as described above, for example, as shown in FIG. There is a method of setting the ignition timing to a value lower than normal (details will be described later), and there is also a method of delaying the ignition timing set by the ignition timing control device from the appropriate value.

[Effect]

A constant speed traveling device is used when traveling continuously at a constant speed on an expressway or the like.

Therefore, the constant speed traveling device is normally set to be able to operate only when the speed is equal to or higher than a predetermined set speed (for example, 60 km/h) in accordance with the traveling speed of the expressway.

Therefore, it is not necessary to activate the constant speed traveling device when starting from a stopped state or when driving at a low speed that is significantly slower than the set speed above, and if the constant speed traveling device is activated in such a state, it may malfunction. It can be determined that

In addition, if the load on the internal combustion engine is large even though the accelerator pedal is not depressed, a malfunction of the constant speed traveling device or a failure such as the throttle link system connecting the accelerator pedal and throttle valve may occur. The throttle valve may be open even though the accelerator pedal is not depressed.

Based on the above consideration, the present invention is based on the above consideration, and the present invention is based on the above considerations, and the present invention is designed to reduce the load on the internal combustion engine when the vehicle speed is less than a predetermined vehicle speed (for example, 401 m/h), which falls within the unnecessary range of the constant speed traveling device, and even though the accelerator pedal is not depressed. When the amount is equal to or greater than a predetermined value, the constant speed traveling device is stopped from operating and the output of the internal combustion engine is limited.

With the above configuration, in the present invention,
If the constant speed traveling device operates when starting or driving at low speed, or if the vehicle is not running at the desired target speed due to a failure in the throttle link system, etc., the constant speed traveling device will be automatically and reliably set. Since the operation of the speed traveling device can be stopped and the output of the internal combustion engine can be limited, controllability can be further improved than in the past.

[Embodiments of the invention]

FIG. 2 and FIG. 3 are diagrams showing one embodiment of the present invention, and FIG.
The figure is an overall configuration diagram, and FIG. 3 is a diagram showing the configuration of the actuator control section and its operation details.

First, in Fig. 2, the part consisting of 1 to 18 (17 is shown in Fig. 3) is a constant speed traveling device (ASCD).
It is.

A battery is connected to the power supply terminal 1 via an ignition switch and a fuse (not shown).

Further, the switching means 21 is turned on when the constant speed traveling device is in normal operation (details will be described later).
The D relay 3 is energized when the main switch 4 of the ASCD is turned on, and its contacts are turned on. A battery (not shown) is connected to the power terminal 1. It is connected to the operating circuit 6 via the switching means 21 and the contacts of the ASCD relay, and is also connected to the controller 9 via the inhibit switch 11 and the brake switch 12. Therefore, during normal operation when the switching means 21 is on, when the main switch 4 is turned on, A
The contact of the SCD relay 3 is turned on, power is connected to the constant speed traveling device, and the constant speed traveling device is put into operation. In this state, the main lamp 4 lights up to indicate that the constant speed traveling device is operating.

On the other hand, a battery is also connected to the power supply terminal 2 via an ignition switch and a fuse (not shown). This power supply terminal 2 is connected to a controller 9 via a stop lamp switch 7 that is turned on when the brake pedal is depressed, and is also connected to a stop lamp 8 that is turned on when the switch is turned on. Therefore, when the brake pedal is depressed, the stop lamp switch 7 is turned on, and information indicating that a brake operation has been performed is transmitted to the controller 9.

Next, the operation circuit 6 will be explained.

The operating circuit 6 is installed on the steering wheel from the viewpoint of operability, and is connected to the controller 9 via a slip ring, that is, a sliding contact provided on the rotating part of the steering wheel.

The operation circuit 6 is composed of a set switch, an acceleration switch, and a resume switch, one end of each of which is connected to the battery via the ASCD relay 3. Further, the other ends of each of the switches are independently connected to the controller 9.

Next, the functions of the set switch, acceleration switch, and resume switch of the operation circuit 6 will be explained.

First, the set switch is a switch for setting the constant speed driving state. For example, if the set switch is temporarily closed while the vehicle is traveling at 60 km/h, the vehicle will continue to travel at a constant speed of 60 km/h. do. In such a constant speed running state, if the set switch is further closed, the vehicle speed is gradually reduced by the internal combustion engine brake. That is, the set switch also has the function of a coast switch.

Next, the accelerate switch has an accelerator function, and if the accelerate switch is kept closed while driving at a constant speed, the vehicle speed will increase sequentially, and then when the accelerate switch is released, the vehicle speed will be maintained at the current speed when the accelerate switch is released. Execute fast driving.

In addition, the resume switch is set to +a at the speed of 60 as mentioned above.
After setting the constant speed driving state in The speed of the previous constant speed run stored in the storage means explained in .

That is, in the above example, the vehicle is reset to a constant speed running state of 60 km/h.

Next, the vehicle speed sensor 10 is connected to the controller 9 and sends speed information to the controller 9 according to the traveling speed of the vehicle. For example, the vehicle speed sensor 10 has a built-in switching means that opens and closes depending on the traveling speed of the vehicle.
As the traveling speed of the vehicle increases, the opening/closing operation of the switching means becomes faster, and an intermittent signal due to the opening/closing operation of the switching means is output as speed information.

In addition, as mentioned above, the power supply terminal 1 is connected to the ASCD relay to the inhibit switch 11 and the brake switch 12.
It is connected to the controller 9 via. The inhibit switch 11 is turned off when the gear lever of the automatic transmission is set to parking range P or neutral range N, and turned on when it is set to other ranges (drive D and reverse R). This is a point of contact.

Further, the brake switch 12, which is a normally closed contact, is turned off when the brake pedal is depressed.

Inhibit switch 11 and brake switch 1 above
2 is turned off, the controller 9
Constant speed driving control is canceled.

Next, the controller 9 will be explained.

The controller 9 includes a microcomputer that executes various control processes related to constant speed driving, a storage device for storing information related to constant speed driving, and a digital computer that calculates the vehicle speed based on speed information from the vehicle speed sensor 10. It has a built-in circuit-based vehicle speed determination section, etc., and outputs various control signals based on information from the operation circuit 6 and vehicle speed sensor 10.

For example, when it is determined that the set switch has been operated based on information from the operation circuit 6, the vehicle speed at the time the set switch was operated is calculated based on speed information from the vehicle speed sensor 10 and stored in the storage means. At the same time, based on the calculated vehicle speed, a control signal is output to indicate a transition to a constant speed driving state at the vehicle speed. Further, when the controller 9 determines that the acceleration switch has been operated, it outputs a control signal to sequentially increase the traveling speed of the constant speed traveling at a predetermined rate. Furthermore, when it is determined that the resume switch has been operated during driving after the constant speed running state has been temporarily canceled due to the operation of the brake switch 12 in conjunction with the brake operation, the speed stored in the storage means is changed. The information is read out and, based on the speed information, a control signal to return to the original constant speed running state is output.

The actuator control section 13 is controlled by each control signal as described above.

Next, the actuator control section 13 will be explained based on FIG.

As shown in FIG. 3(A), the actuator control section 13
is a negative pressure pump 14. It is composed of an air valve 15 and a release valve 16.

Then, according to the control signal given from the controller 9 as described above, the negative pressure pump 1
4. By controlling the operations of the air valve 15 and the release valve 1G, desired negative pressure is generated, and the actuator 17 (negative pressure valve) is actuated by the negative pressure.

As shown in FIG. 3(B), when the constant speed running control is not activated, the negative pressure pump 14 is stopped, and the air valve 15 and release valve 16 are always "open" so that the inside of the actuator 17 is not activated. becomes atmospheric pressure, and the actuator 17
The operating amount of is O. Also, when constant speed driving control is activated,
Depending on the relationship between the target speed and the actual vehicle speed, the negative pressure pump 1
At the same time, the opening and closing of the air valve 15 and the release valve 16 are controlled, thereby controlling the amount of operation of the actuator 17.

The actuator 17 is connected to a throttle valve of an internal combustion engine (not shown) by an ASCD wire, and the throttle valve opening is adjusted according to the operating amount of the actuator 17, thereby controlling the vehicle speed to the desired target speed as described above. be done.

Further, in FIG. 2, when the constant speed driving device is in operation, the cruise lamp 18 is turned on in response to a signal from the controller 9, indicating that the vehicle is in a constant speed driving state.

- Next, the control means, which is a feature of the present invention, including the switching means 21 described above, will be explained.

In FIG. 2, numeral 24 is a vehicle speed sensor that detects the vehicle speed, and for example, a sensor similar to the aforementioned vehicle speed sensor IO can be used. Further, it can also be used in common with the vehicle speed sensor 10.

Further, 25 is an accelerator pedal sensor that detects whether the accelerator pedal is being depressed, and for example, a switch that is turned on when the accelerator pedal is being depressed can be used.

Further, 26 is a load sensor that detects the amount of load on the internal combustion engine, and for example, a sensor that detects the throttle valve opening of the internal combustion engine or a sensor that detects the amount of intake air can be used.

Note that each of the above-mentioned sensors 24 to 26 may be provided as an independent sensor, but a device provided as a sensor for a fuel injection control device of an internal combustion engine may be used in common for the device of the present invention. Good too.

Next, the control means 22 is composed of a dedicated analog circuit, a dedicated digital circuit, or a microcomputer (can be shared with a computer for a fuel injection control device, etc.), and receives signals from each of the means 24 to 26 above. , based on these detection results, performs a determination calculation as described later, and outputs an ASCD cut signal 23 and a fuel restriction command signal 28 when a predetermined state is determined.

Further, the switching means 21 is a transistor switching circuit or a relay, and is normally turned on, but turned off when the ASCD cut signal 23 mentioned above is applied.

When the switching means 21 is turned off as described above, the power to the constant speed traveling device such as the controller 9 is cut off, in the same way as when the main switch 4 is turned off, so that the operation of the constant speed traveling device is ensured. be stopped.

In addition, instead of the switching means 21, a switching device is used in which the output terminal (1) of the controller 9, that is, the connection point You can also use means.

In addition to stopping the operation of the constant speed traveling device as described above, it also limits the amount of fuel supplied to the fuel supply device 27 (fuel injection control device or electronically controlled carburetor) by the fuel restriction command signal 28, or shuts off the fuel. The output of the internal combustion engine can be limited by lowering the rotational speed. Note that details regarding each of the above controls will be described later.

Next, the state determination calculation in the control means 22 will be explained.

FIG. 4 is a flowchart showing an embodiment of the state determination calculation when the control means 22 is constructed of a microcomputer. This flow is repeatedly calculated at predetermined time intervals.

In FIG. 4, at P□, the vehicle speed is a predetermined value (for example, 4 o
b/h) or less.

Next, in P2, it is determined whether the accelerator pedal is depressed.

Next, at P, the load amount (throttle valve opening or intake air i)
is greater than or equal to a predetermined value. Note that this predetermined value is 1
For example, the load amount is set to a value slightly larger than the load amount when the accelerator pedal is not depressed during normal operation, that is, when the throttle valve is fully open (idle opening).

If all of the above P
At Ps, the fuel restriction command signal 28 is output to limit the output of the internal combustion engine, and at Ps, the A S CD cuff h (
No. 71 (ASCD cut signal 23 in FIG. 2 (7) above) is output. This signal turns off the switching means 21 of FIG. 2 as described above.

The operation of the constant speed traveling device is stopped.

Next, a method of limiting the output of the internal combustion engine at P4 will be described.

Examples of methods to limit the output of an internal combustion engine include: ■ Setting a predetermined upper limit on the amount of fuel supplied; ■ Setting the fuel cutoff rotational speed (the rotational speed at which fuel is cut off when it reaches that rotational speed) from the normal value. There is a way to set it to a lower value.

First, ■method of setting a predetermined upper limit value for the fuel supply amount is to set the upper limit value of the fuel supply amount to 1, for example, 3 of the normal maximum fuel supply amount.
This limit is set to a value of about 0%, so that even if the throttle valve is opened wide and the amount of intake air increases, fuel will not be supplied above the above upper limit value. In this way, even if the throttle valve is fully opened, only a small amount of fuel will be supplied, resulting in a lean mixture and lean combustion, which will significantly reduce the engine's output and make rapid acceleration impossible. . In this state, the engine will be in a malfunction state, but if the above upper limit value is set appropriately, there is no risk that the engine will stop.

To realize this method, for example, if the fuel supply device 27 is a fuel injection control device, it is sufficient to set an upper limit value for the fuel injection pulse @TP that is lower than the maximum value in normal times. Furthermore, in the case of an electronically controlled carburetor, the fuel passage or mixture passage of the main system of the carburetor may be configured to be shut off by a solenoid valve. In this case, the slow system and power system can be operated, so low speed driving is possible and the vehicle will not be completely unable to travel.

Next, ■method of setting the fuel cutoff rotational speed to a value lower than the normal value is to set the fuel cutoff rotational speed to the normal value (a value determined depending on the type of internal combustion engine, for example 7000rpm).
a+) (e.g. 2500 rpm)
It is set to . In this way, the throttle valve is opened and the rotational speed increases, and as soon as the above-mentioned set value is reached, the fuel is cut off, so that the rotational speed does not increase above that value.

Next, FIG. 5 is a flowchart 1 to 1 showing calculations for realizing the method (2) above when the fuel supply device 27 is a fuel injection control device.

In FIG. 5, first, PLll reads the basic injection pulse IIIgTp. The value of Tp is also calculated from the intake air amount Q and the rotational speed N according to the formula Tp=-Q/N (K is a constant). Note that the actual injection amount Ti is obtained by applying various corrections to the above TP as described later.

Next, in P1□, various correction coefficients COE F are read. Examples of this correction coefficient include correction coefficients such as low water temperature increase, starting increase, post-start increase, post-idling increase, acceleration/deceleration correction, and high water temperature increase.

Next, in P□2, the air-fuel ratio correction coefficient α is read.

This air-fuel ratio correction coefficient α is a correction coefficient when feedback control is performed to maintain the air-fuel ratio of the air-fuel mixture at a predetermined value.

Next, in the P-engine, the voltage correction amount Ts corresponding to the fluctuation of the battery voltage is read.

Next, P2. Now, the above P□. ~P1. Fuel injection; i T i is calculated from the value read in.

Note that the above Ti is calculated, for example, according to the following equation (1).

Ti=TpXCOEFXα+Ts −(1) Then, P
o, it is determined whether the rotational speed N of the internal combustion engine is equal to or higher than the fuel cutoff rotational speed NC=D set at P4 in FIG. In this case, go to PlG and set the FC flag, then go to Pi□ to set the fuel injection amount Ti to Q (that is, fuel cutoff) and output it.

P8. If the answer is No, the process goes to Pz8, and it is determined whether the rotational speed N is equal to or higher than the recovery rotational speed NR (a value at which fuel cutoff is stopped and fuel supply is restarted when the rotational speed becomes lower than the recovery rotational speed NR).

If Pz8 is No, that is, if the rotational speed has decreased to less than the recovery rotational speed NR, P2. After clearing the FC flag in step P2□, the value of the fuel injection amount Ti calculated in step P14 is output as is.

If YES in Pz8, go to Pz9.

In the case of SET in Plg, the FC flag is set to Sera 1~
In the case of the fuel cut-off state, the process goes to P□7 and continues the fuel cut-off state.

In the case of CLR at Po, the value of the fuel injection amount Ti is output as is through the path Pz o s P z □.

As described above, in the flowchart of FIG. 5, fuel is cut off when the rotational speed of the internal combustion engine reaches NG, so it is possible to control the rotational speed so that it does not exceed NC. Therefore, for example, even if a failure occurs such as a jam in the throttle link system that adjusts the throttle valve opening and the throttle valve is left open, the rotation speed can be controlled so that it does not exceed N0. I can do it.

Therefore, if the value of NC=D is set to a low value that does not cause any operational problems, stable control can always be performed.

〔Effect of the invention〕

As explained above, in the present invention, when the vehicle speed is below a predetermined vehicle speed that falls within the unnecessary range of the constant speed traveling device,
In addition, if the load on the internal combustion engine is equal to or higher than a predetermined value even though the accelerator pedal is not depressed, the system is configured to stop the operation of the constant speed traveling device and limit the output of the internal combustion engine. Therefore, if the constant speed traveling device operates when starting or driving at low speed, or if the vehicle does not travel at the desired target speed due to a failure in the throttle link system, etc., the automatic and reliable Since it is possible to stop the operation of the constant speed traveling device and to limit the output of the internal combustion engine, an excellent effect can be obtained in that controllability can be further improved than in the past.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the functions of the present invention, FIGS. 2 and 3 are illustrations of an embodiment of the invention, and FIGS. 4 and 5 are flowcharts showing the calculation contents in the above embodiment. This is an example diagram. Explanation of symbols> 1.2...Power terminal 3...ASCD relay 4
...Main switch 5...Main lamp 6...
Operation circuit 7...stop lamp switch 8...stop lamp 9...controller 1
0... Vehicle speed sensor 1 inhibit switch 12... Brake switch 13... Actuator control section I4... Negative pressure pump I5... Air valve 16
...Release valve 17...Actuator 1
8...Cruise lamp 2I...Switching means 22...Control means 23...ASCD cutie number a 24...Vehicle speed sensor 25...Accelerator pedal sensor 26...Load sensor 27...Fuel supply device 28...Fuel restriction command signal ioo...Constant speed traveling device 101...Internal combustion engine 1
02...Vehicle speed detection means 103...Accelerator pedal detection means

Claims (1)

[Claims] In a control device for a vehicle equipped with a constant speed traveling device that automatically runs the vehicle at a predetermined target speed by feedback controlling the throttle valve opening of the internal combustion engine so that the actual vehicle speed matches the target vehicle speed, a vehicle speed detection means for detecting the
an accelerator pedal detection means for detecting whether or not the accelerator pedal is depressed; a load detection means for detecting the amount of load on the internal combustion engine; and a load detection means for detecting the amount of load on the internal combustion engine. A control device for a vehicle, comprising: control means for stopping the operation of the constant speed traveling device and limiting the output of the internal combustion engine when the load amount is equal to or higher than a predetermined value when the engine is not running.