JPH0617689A - Internal combustion engine controller - Google Patents

Abstract

PURPOSE:To improve controllability in carrying out constant speed traveling control together with other control for internal combustion engine output, in a controller which controls switching of the throttle control mode for changing the control characteristics of the opening of a throttle valve to the output torque of an internal combustion engine. CONSTITUTION:In controlling the switching of a throttle control mode for switching the characteristics of the opening of the first throttle valve 21 vs. the output torque of an engine 1 by controlling the second throttle valve 22 according to the opening of the first throttle valve 21, a gain G for constant speed traveling control by a constant speed traveling control circuit 10 is changed to a larger value when a change in the output torque of the engine 1 to a change in the opening of the first throttle valve 21 is moderate. As a result, in a throttle control mode for low mu road, the driving amount of a constant speed traveling actuator 25 for a deviation between actual vehicle speed and an objective vehicle speed is set to a larger value, and the vehicle speed is controlled to the objective vehicle speed immediately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine control device, and more particularly to an internal combustion engine control device having a function of changing the relationship of the output change of the internal combustion engine with respect to the drive amount of an actuator that changes the intake air amount.

[0002]

2. Description of the Related Art The output of an internal combustion engine is usually controlled by the amount of intake air. As a mechanism to change the intake air amount,
For example, it is common to change the opening of a throttle valve provided in the intake passage. Many throttle valves are connected to an accelerator pedal by a mechanical link, but it is also known that the throttle valve is driven by an actuator such as a motor. Further, recently, there has been proposed one in which another throttle valve (hereinafter referred to as a sub-throttle valve) is provided in the intake air passage and the opening of the sub-throttle valve is controlled according to the opening of the main throttle valve. ing. In such a configuration, by controlling the sub-throttle valve, the output characteristics of the internal combustion engine are made different with respect to the opening of the main throttle valve, and a plurality of throttle control modes are realized. The throttle control mode is switched based on the running state of the vehicle to properly control the output of the internal combustion engine.

An example of such throttle control mode switching control is one that determines the friction coefficient μ of the road surface and suppresses an increase in the output torque of the internal combustion engine due to the operation of opening the main throttle valve on a low μ road. . The output of the internal combustion engine is suppressed according to the friction coefficient μ of the road surface to prevent the occurrence of slip. This control will be described with reference to FIG. 8 showing the characteristics of the internal combustion engine when the relationship between the opening of the main throttle valve and the output torque of the internal combustion engine is made different by controlling the sub throttle valve. In the figure, the solid line A indicates the output torque of the internal combustion engine with respect to the main throttle valve opening α when the sub throttle control is not performed, that is, when the sub throttle valve is fully opened. The broken line B indicates the characteristics for high μ road, and the dashed line C
Shows the characteristics for low μ road. In the high-μ road sub-throttle control, the opening of the sub-throttle valve is controlled so that a high internal combustion engine output torque is obtained with respect to the opening of the main throttle valve. On the other hand, on the low μ road, the sub-throttle control is performed to suppress the output torque of the internal combustion engine with respect to the opening of the main throttle valve.

As is apparent from the figure, when the sub-throttle valve is controlled for the low μ road, the output torque of the internal combustion engine is suppressed to a low level even if the main throttle valve is considerably opened, and the drive wheels are excessively large. Torque is not transmitted. Therefore, on a low μ road, slip or the like will not occur due to excessive accelerator operation. Another advantage of controlling the sub-throttle valve is that the relationship between the output torque of the internal combustion engine and the opening degree of the main throttle valve (accelerator operation amount) can be freely designed. Therefore, for example, it is easy to realize a characteristic excellent in driving operability, such as a linear relationship between the two.

[0005]

However, in the internal combustion engine control device for performing such switching control of the throttle control mode, another control for controlling a physical quantity (for example, vehicle speed, acceleration, etc.) related to vehicle running which can be controlled by the output of the internal combustion engine. If, for example, constant speed traveling control (cruise control) is also performed, there is a problem that other controls do not function sufficiently in a specific throttle control mode. This problem will be described with reference to FIG. 8 described above as an example of a configuration in which constant speed traveling control is performed by controlling the opening of the main throttle valve.

When performing constant-speed traveling control, the traveling speed of the vehicle is detected by a vehicle speed sensor or the like, the deviation from the target vehicle speed is obtained, and the main throttle valve is driven. Normally, in such constant speed traveling control, the main throttle opening required for the target vehicle speed is estimated, and the actuator is driven until the required main throttle opening is obtained.
When a deviation occurs between the target vehicle speed and the actual traveling speed, feedback control is performed based on this deviation or in addition to this, an amount that integrates the deviation to open the throttle to maintain constant speed traveling. Control the degree.

Now, assuming that the output torque of the internal combustion engine required to achieve the target vehicle speed is Q0, as shown in FIG. 8, when the sub-throttle valve is controlled for a high μ road (broken line B ), The opening of the main throttle valve to be realized is B0. If, for example, the vehicle speed decreases from this state due to approaching an ascending slope and the required torque for maintaining constant speed traveling becomes Q1, the required opening degree of the main throttle valve becomes B1. Therefore, the actuator follows the target vehicle speed by controlling the main throttle valve from the opening B0 to the opening B1. On the other hand, when the sub-throttle valve is controlled for the low μ road (dashed line C), the main throttle valve opening for obtaining the output torque Q0 becomes C0, and the required torque becomes Q1 due to the climbing gradient. Then,
The required opening degree of the main throttle valve is C1. In this case, the actuator has to control the main throttle valve from the opening C0 to the opening C1, and compared with the case where the sub-throttle control for the high μ road is being performed (B0 → B1), the opening should be controlled. It will be immediately understood that the degree of change is large and it takes time to complete the control.

In actual control, the output torque Q1 for maintaining constant speed running against disturbance such as road gradient is not known at the start of control, so the actuator is driven with a drive amount based on the deviation between the target vehicle speed and the actual vehicle speed. However, the vehicle speed will gradually approach the target vehicle speed. If it takes time to complete the control of the main throttle valve, that is, to obtain the required engine torque, it takes a considerable time for the reduced vehicle speed to return to the target vehicle speed. Therefore, the fluctuation of the vehicle speed during that time becomes large. For such a problem, simply increasing the drive amount based on the vehicle speed deviation would cause the internal combustion engine output torque to change greatly even if the opening of the main throttle valve changes slightly when sub-throttle control is not performed. However, it causes a new problem such as an overshoot in the control of vehicle speed, which is not a realistic solution.

The above is a detailed description of the problems in the case of performing constant-speed running control together with the vehicle in which the sub-throttle control is performed. However, these problems are not limited to the case where the sub-throttle control is performed, and the intake air amount Essentially, there is a structure in which the relationship between the variable drive amount of the actuator and the change in the output of the internal combustion engine can be changed. For example,
A configuration for switching the number of ignition cylinders in a multi-cylinder internal combustion engine,
In a configuration in which a single throttle valve is driven by an actuator and a plurality of throttle control modes are realized by switching the calculation formulas and maps for calculating the drive amount, constant speed running control and traction control, etc. are performed together with these controls. If you do, the same problem occurs.

The internal combustion engine control device of the present invention solves these problems and makes it possible to change the relationship between the drive amount of the actuator that changes the intake air amount and the output change of the internal combustion engine. An object of the present invention is to suitably control a controllable physical quantity that is influenced by the output of the engine and is related to vehicle travel.

[0011]

The internal combustion engine control system of the present invention is driven by an actuator AC as shown by the solid line in the block diagram of FIG. 1 to vary the intake air amount of the internal combustion engine EG. Means M1, an internal combustion engine characteristic changing means M2 that changes the relationship of the output change of the internal combustion engine EG with respect to the drive amount of the actuator AC, and vehicle speed, acceleration, etc. that are influenced by the output of the internal combustion engine EG and are related to vehicle travel. An actuator control means M3 for determining a drive amount of the actuator AC is provided in a direction to bring a controllable physical quantity closer to a target value, and the actuator control means M3 further includes the drive amount by the internal combustion engine characteristic changing means M2. And the output of the internal combustion engine are affected by the output of the internal combustion engine EG being small with respect to the change in the drive amount. In the state that has been changed to the engagement,
In determining the drive amount, the gist is that the drive amount determining / correcting means M4 for increasing the drive amount is provided.

When this internal combustion engine control device is applied to vehicle speed control, in addition to the above configuration, vehicle speed detection means N1 for detecting the speed of the vehicle, as additionally shown in FIG. 1 with a broken line.
And a target vehicle speed setting means N2 for setting a target vehicle speed, the intake air amount varying means M1 is a throttle valve SV whose opening is adjusted by an actuator AC, and the actuator control means M3 is used for the vehicle speed and the target vehicle speed. The vehicle speed response control means N3 that applies feedback control to the actuator AC in a direction to reduce the deviation can be provided.

Further, considering a so-called sub-throttle control configuration as a configuration in which the relationship between the drive amount of the actuator AC for varying the intake air amount and the output change of the internal combustion engine EG can be varied, a broken line is similarly drawn. As additionally shown, the intake air amount varying means M1 has a first throttle valve SV whose opening is adjusted by the first actuator AC1.
1 and a second throttle valve SV2 whose opening is adjusted by a second actuator AC2, and the internal combustion engine characteristic changing means M2 is a throttle having a relationship between the first throttle valve opening and the internal combustion engine output. Characteristic specifying means L21 for specifying the characteristic of the valve opening and the actual first throttle valve opening are detected, and the second throttle valve opening relative to the first throttle valve opening is specified by the output of the internal combustion engine. Second throttle valve opening control means L22 for controlling so as to obtain the specified characteristics.
The drive amount determination / correction means M4 is a means for compensating the drive amount of the second actuator AC2 in accordance with the throttle valve opening characteristic realized by the internal combustion engine characteristic changing means M2. Can be taken.

[0014]

In the internal combustion engine control device of the present invention configured as described above, the internal combustion engine characteristic changing means M2 is related to the internal combustion engine EG whose intake air amount is changed by the intake air amount changing means M1 driven by the actuator AC. , The change of the output of the internal combustion engine EG with respect to the drive amount of the actuator AC is changed. On the other hand, the actuator control means M3
The drive amount of the actuator AC is determined in such a direction that a controllable physical quantity that is influenced by the output of the internal combustion engine EG and is controllable for vehicle running, such as vehicle speed and acceleration, approaches a target value.

When the physical quantity is controlled in a state where the output characteristics of the internal combustion engine EG are different, in the internal combustion engine control device of the present invention, the drive amount determination correction means M4 provided in the actuator control means M3 drives the actuator AC. In the state where the relationship between the amount and the internal combustion engine output is changed to a relationship in which the output of the internal combustion engine EG is slightly affected by the change in the drive amount, when determining the drive amount, the drive amount is set to a larger value. To do. Therefore, the drive amount of the actuator AC is determined so as to compensate for the characteristic of the output of the internal combustion engine EG, and the control of the physical amount is improved as compared with the case where the drive amount determination correction means M4 is not acted.

For example, the vehicle speed is taken as the physical quantity to be controlled, and the vehicle speed response control means N3 provided in the actuator control means M3 determines the drive amount of the actuator AC based on the deviation between the actual vehicle speed and the target vehicle speed. Consider a case where constant speed traveling control is performed. When the vehicle speed increases or decreases due to the gradient of the road, the vehicle speed response control means N3 determines the drive amount of the actuator AC.
In a state in which the output of the internal combustion engine EG is changed to have a small influence on the change in the drive amount of the above, the conventional method of driving the actuator AC with the same drive amount causes a delay in control and increases the vehicle speed. It takes time to recover the vehicle speed such as a fall. On the other hand, in the internal combustion engine control device of the present invention, in the state where the drive amount determination correction means M4 is changed to a relationship in which the output of the internal combustion engine EG is slightly affected by the change in the drive amount of the actuator AC. The AC drive amount of the actuator is set to a large value. Therefore, the delay of the vehicle speed control becomes small, the decrease in the vehicle speed becomes small, and the vehicle speed returns to the target vehicle speed in a short period of time.

Furthermore, the present invention is applied to a structure for performing so-called sub-throttle control, and internal combustion engine characteristic changing means M2 is applied.
The characteristic specifying means L21 provided in the first throttle valve S whose opening is adjusted by the first actuator AC1.
The throttle valve opening characteristic, which is the relationship between the opening of V1 and the output of the internal combustion engine, is specified, and the second throttle valve opening control means L2.
Consider a case in which the second controller detects the actual first throttle valve opening and controls the second throttle valve opening relative to the first throttle valve opening so that the output of the internal combustion engine has the specified characteristic. In this case, by controlling the opening of the second throttle valve according to the opening of the first throttle valve,
The output of the internal combustion engine is made different for the same first throttle valve opening to realize a specified one of the plurality of throttle valve opening characteristics. The drive amount of the second actuator is compensated according to the throttle valve opening characteristic. Therefore, no matter how the relationship between the output of the internal combustion engine EG and the opening of the first throttle valve SV1 is set, the drive amount of the first actuator AC1 for controlling the physical quantity depends on the throttle opening characteristic. The delay of control is corrected to compensate for the delay of control.

[0018]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above. FIG. 2 is a schematic configuration diagram of an internal combustion engine control device as an embodiment. This internal combustion engine control system uses an engine 1
An intake air adjusting mechanism 5 that is provided in an intake passage 3 that communicates with the intake manifold 2 of FIG.
It is composed of a constant speed traveling control circuit 10 for performing constant speed traveling control for keeping the vehicle speed constant, an engine output control circuit 15 for controlling the sub-throttle valve, and other sensors and switch groups. First, the configuration of each unit will be described.

The intake air adjusting mechanism 5 corresponding to the intake air amount varying means includes a first throttle valve 21 connected to an accelerator pedal 20 by a mechanical link, a second throttle valve 22 provided upstream of the first throttle valve 21, and a first throttle valve 21. Is a constant speed traveling actuator 25 that is connected by a well-known link mechanism and drives the same, a throttle actuator 27 that drives the second throttle valve 22, and a first
A first throttle valve opening sensor 31 that detects the opening of the throttle valve 21 and a second throttle valve opening sensor 32 that detects the opening of the second throttle valve 22 are provided.

The first throttle valve 21 is connected to the accelerator pedal 20 and the constant speed traveling actuator 25. The relationship between the constant speed traveling actuator 25 and the accelerator pedal 20 is as follows. The first throttle valve 21 is configured such that the opening / closing control of the first throttle valve 21 by the constant speed traveling actuator 25 has priority over the opening / closing of the first throttle valve 21 by the driver's operation of the accelerator pedal 20. . However, if the first throttle valve opening indicated by the operation of the accelerator pedal 20 exceeds the first throttle valve opening as a result of the opening / closing control of the first throttle valve 21 by the constant speed traveling actuator 25, the accelerator pedal 20 The first throttle valve opening instructed by stepping has priority.

The constant speed traveling control circuit 10 has an internal circuit 4 for converting an input signal into a digital signal or the like as its internal circuit.
1 and a CPU (Central Processing Unit) 43 as a central processing unit incorporating ROM and RAM
And an output circuit 45 that outputs various output signals in response to an instruction from the CPU 43. A control program and initial data are stored in the ROM incorporated in the CPU 43, and similarly, the data input via the input circuit 41 and the data necessary for arithmetic control are temporarily stored in the RAM, and the CPU 43 is provided at any time. Read and written by. In this input circuit 41, the vehicle speed detection value from the vehicle speed sensor 47,
The state of the constant speed traveling set switch 49 for setting the constant speed traveling instruction and the target vehicle speed, the actuator opening signal from the constant speed traveling actuator 25, and the first throttle valve from the first throttle valve opening sensor 31. An opening signal (including an ON / OFF signal of an idle contact) and an output signal from an engine output control circuit 15 described later are input. On the other hand, the output circuit 45 outputs a signal to the engine output control circuit 15, which will be described later, together with a drive signal to the constant speed traveling actuator 25.

The constant-speed traveling control circuit 10 has a vehicle speed sensor 47 when the constant-speed traveling set switch 49 is turned on.
The vehicle speed detection value is taken in to monitor the vehicle speed, and a drive signal corresponding to the deviation between the vehicle speed and the set vehicle speed (target vehicle speed) is output to the constant speed traveling actuator 25 via the output circuit 45. Constant speed traveling actuator 25 that receives this drive signal
Opens and closes the first throttle valve 21 via the link mechanism. As a result, the intake air amount of the engine 1 increases and decreases, and the output thereof also increases and decreases, and the vehicle speed is gradually controlled toward the target vehicle speed. Details such as calculation of the drive signal of the constant speed traveling actuator 25 will be described later.

The engine output control circuit 15 has almost the same internal circuit as the constant speed traveling control circuit 10. That is, an input circuit 51 for converting an input signal from an external sensor or the like into a digital signal, a CPU (Central Processing Unit) 53 as a central processing unit having a built-in ROM and RAM, and various instructions received from the CPU 53. And an output circuit 55 that outputs the output signal of. Input circuit 5
1, a communication signal from the constant speed traveling control circuit 10, a signal from each switch and sensor group, a throttle control mode instruction signal from the throttle control mode changeover switch 57, and a second throttle valve opening degree. Sensor 32
The second throttle valve opening signal from the first throttle valve opening signal and the first throttle valve opening signal from the first throttle valve opening sensor 31 are input. Although illustration of the detector is omitted, the front wheel speed detection value and the rear wheel speed detection value corresponding to the rotation speeds of the front wheels and the rear wheels, the engine rotation speed signal indicating the rotation speed of the engine 1, and the transmission (not shown) A shift position signal indicating the shift shift position of is also input. On the other hand, the output circuit 5
Reference numeral 5 outputs a lighting / extinguishing signal of a control mode display indicator 59 provided in the instrument panel, and also outputs information of the throttle control mode to the input circuit 41 of the constant speed traveling control circuit 10. In this embodiment, information is exchanged between the constant speed traveling control circuit 10 and the engine output control circuit 15 by using an input / output circuit as a simple on / off signal, but using a communication port. It is also possible to connect both of them and exchange necessary information by communication according to a predetermined protocol.

The engine output control circuit 15 includes front wheels
The engine output is controlled based on the determination of the high μ road / low μ road performed by calculating the slip ratio of the driving wheels from the rotational speed of the rear wheels, or based on the setting of the control mode changeover switch 57. For example, when it is determined that the slip ratio is appropriate and the vehicle is traveling on a high μ road and it is basically unnecessary to suppress the engine output, as shown in FIG. 3, the opening degree of the first throttle valve 21 is increased. In order that the output torque Q of the engine 1 has a substantially linear relationship with respect to α (broken line B),
The opening β of the second throttle valve 22 is controlled. In this case, the opening of the first throttle valve 21 and the engine 1
The mode that realizes the relationship with the output torque of is referred to as a high μ road throttle control mode. For reference, the solid line A shows the relationship between the first throttle valve opening α and the engine output torque Q when the second throttle valve 22 is fully opened.

On the other hand, when it is judged that the vehicle is traveling on a low μ road with a high slip ratio, the opening of the second throttle valve 22 relative to the opening of the first throttle valve 21 is set to the total of both throttle valves. Control is performed so that the opening degree of is reduced. That is, as shown by the one-dot chain line C in FIG. 3, even if the accelerator pedal 20 is operated in the same manner as the high μ road to open the first throttle valve 21, the output torque of the engine 1 is suppressed so that the second torque is suppressed. Throttle valve 22
Is controlled. The mode that realizes the relationship between the opening of the first throttle valve 21 and the output torque of the engine 1 in this case is called a low μ road throttle control mode. The opening degree of the second throttle valve 22 relative to the opening degree of the first throttle valve 21 for the high μ road throttle control mode and the low μ road throttle control mode is determined by the CPU 5
Each of them is stored in advance in the ROM built in 3.
Instead of the determination of the high μ road / low μ road, the second throttle valve opening control is performed according to the instruction signal of the throttle control mode changeover switch 57 operated by the driver, that is, the throttle control mode desired by the driver. You can also do The control of the opening degree of the second throttle valve 22 corresponds to the internal combustion engine characteristic changing means.

The configurations and functions of the constant speed traveling control circuit 10 and the engine output control circuit 15 have been briefly described above. Next, the processing performed by the constant speed traveling control circuit 10 will be described in detail. FIG. 4 is a flowchart showing a gain setting processing routine executed by the interrupt processing at every predetermined time, and FIG. 5 is a flowchart showing a constant speed traveling control routine executed by the constant speed traveling control circuit 10. Both processes correspond to the drive amount determination correction means and the actuator control means.

The gain setting processing routine will be described first. This routine is activated by the timer built in the CPU 43 at predetermined time intervals, and first performs a process of reading the throttle control mode being executed by the engine output control circuit 15 via the input circuit 41 (step S100). Since the engine output control circuit 15 outputs the throttle control mode currently being controlled to the output circuit 55, the constant speed traveling control circuit 10 can read the current throttle control mode by reading this signal. it can.

Subsequently, the read throttle control mode is determined (step S110), and when the throttle control is not performed (other cases), the driving gain G of the constant speed traveling actuator 25 is set to a predetermined value G.
a is set (step S120), and "RTN" is set as it is.
To exit this routine. On the other hand, when it is determined that the throttle control mode or the control mode for the high μ road is set, the gain G is set to a value Gb corresponding to a gain larger than the predetermined value Ga (step S130), and the other is for the low μ road. If it is determined that the throttle control mode is
A value Gc larger than the value Gb is set in the gain G (step S140), the process goes to "RTN" and the present routine ends.

Through the above processing, the engine output control circuit 15 determines whether the road surface is a high μ road or a low μ road based on the slip ratio of the wheels, and the opening degree of the second throttle valve 22 is set in the throttle control mode according to this. When controlling, the constant speed traveling control circuit 10 sets the driving gain G of the constant speed traveling actuator 25 to a value according to the throttle control mode.

On the other hand, the constant speed traveling control circuit 10 executes a constant speed traveling control routine by an interrupt processing routine which is started every predetermined time TM, in addition to the gain setting processing routine. When this constant speed traveling control routine is started, first, a process of reading the vehicle speed Vn from the vehicle speed sensor 47 via the input circuit 41 is performed (step S200). Then, a process for obtaining the acceleration a based on the vehicle speed Vn is performed (step S210). The acceleration a can be obtained by differentiating the vehicle speed Vn, but in the embodiment, it can be easily obtained from the interval TM of the interrupt processing routine and the vehicle speed change between them.

Then, a process for obtaining the predicted vehicle speed Vsk is performed (step S220). The predicted vehicle speed Vsk is a speed at which the vehicle is predicted to reach after Tsk when the vehicle accelerates and decelerates at the current acceleration with respect to the current vehicle speed Vn, and is calculated by the following equation (1). Vsk = Vn + a · Tsk (1)

Next, a process for obtaining the target opening MA of the constant speed traveling actuator 25 is performed (step S230).
The target opening MA is calculated by the following equation (2). In this formula (2), SA is the necessary actuator opening for traveling on a flat road at a certain vehicle speed, and is the initial opening when performing constant speed traveling. Further, IDLn is an opening (margin opening) corresponding to a play in the rotation angle of the constant speed traveling actuator 25 that exists before the first throttle valve 21 starts to open from the fully closed state. Vt is the target vehicle speed Vsk
Is the predicted vehicle speed, so (Vt-Vsk) is the interval T
It becomes the vehicle speed deviation after SK. This predicted vehicle speed Vsk
Instead, the actual vehicle speed Vn itself may be used. The product of the vehicle speed deviation and the control gain G, the auxiliary coefficient K, the initial opening SA
And the target actuator opening MA is obtained by adding the margin opening IDLn.

Then, based on the target opening MA thus obtained and the current opening An of the constant speed traveling actuator 25, a process for calculating the drive amount D for the constant speed traveling actuator 25 is performed (step S240). The drive amount D for the constant speed traveling actuator 25 is obtained by the following equation (3). D = C · (MA-An) (3) In the equation (3), C is a correction coefficient. Since the drive amount D is obtained according to the equation (3), the drive amount D becomes a value proportional to the deviation between the current constant speed traveling actuator 25 opening MA and the target opening An.

Next, the constant speed traveling actuator 25 is driven by the driving amount D thus obtained (step S25).
0), exit to "RTN" and end this routine. In the present embodiment, the constant speed traveling actuator 25 is a DC motor and is driven by supplying a current having a duty ratio proportional to the driving amount D. If the result of the calculation is negative, the polarity of the current flowing through the constant speed traveling actuator 25 is reversed to control the forward / reverse rotation of the constant speed traveling actuator 25.

According to the present embodiment described above, the constant speed traveling control circuit 10 determines the current throttle control mode, and the gain G in the constant speed traveling control is determined according to the throttle control mode by the engine output control circuit 15. Is set. In the low μ road throttle control mode in which the output change of the engine 1 is small with respect to the opening change of the first throttle valve 21, the gain G is set to a value Gc higher than that in the high μ road throttle control mode. . As a result,
In the present embodiment, as illustrated by the solid line in FIG. 6, when the vehicle approaches a climbing slope from a flat road, the first throttle valve opening α immediately increases and the control is completed within the time T1. To do. Therefore, the fall of the vehicle speed V can be suppressed within a small range ΔV1. Further, when the vehicle approaches the road surface with a downward slope, the first throttle valve 21 is immediately controlled in the closing direction, and the control is completed within the time T3. In the figure, the variation of the vehicle speed V in this case is suppressed within the range of ΔV3.

On the other hand, in the conventional configuration, when the throttle control mode is the mode for the low μ road, the gain G is not changed to a particularly large value. As shown in FIG.
The change in the output of the engine 1 with respect to the change in the opening degree was small. Therefore, in this case, the opening degree α of the first throttle valve 21 changes only slowly, as illustrated by the broken line in FIG. 6, and as an example, when the control reaches the climbing slope, the time T2 is reached. It took time T4 when approaching the downhill slope. Same drive amount D
Since the change in the opening α of the first throttle valve 21 with respect to is small, the variation of the vehicle speed V becomes large compared to the present embodiment in which the gain G is set to a large value Gc (ΔV2, Δ V4).

In the present embodiment, on the other hand, in the calculation of the drive amount D according to the equation (3), the gain G is switched according to the throttle control mode. Therefore, the gain G is increased in the throttle control mode for low μ road (G = G
c) In the throttle control mode for the high μ road or the control mode in which the throttle control is not performed (the state where the second throttle valve is fully opened), the gain G is set lower than that in the throttle control mode for the low μ road (G = Gb, G
a). Therefore, regardless of the throttle control mode, the time to complete the control is short, and hunting or the like does not occur in the control. In the embodiment, the gain G
c was set to about twice the gain Gb, but the gain G
The setting may be determined for each vehicle type based on the traveling characteristics of the vehicle, the throttle control mode, and the like. Further, it may be configured to learn the optimum gain.

Since the constant speed running control can be appropriately performed regardless of the state of the throttle control mode, for example, when the driver depresses the accelerator pedal 20 to perform acceleration or the like during execution of the constant speed running control. Indicates that the throttle control according to the road surface condition is continued and the output torque of the engine 1 is not unnecessarily increased on the low μ road. Therefore,
Even in such a case, the occurrence of slip can be prevented in advance.

Next, a second embodiment of the present invention will be described. The engine control device as the second embodiment has the same hardware configuration as that of the first embodiment, and is different only in the processing performed by the constant speed traveling control circuit 10. The constant speed running control circuit 10 of the second embodiment executes the auxiliary coefficient processing routine shown in FIG. 7 instead of the gain setting processing shown in FIG.

When the constant speed running control circuit 10 of this embodiment starts the auxiliary coefficient processing routine shown in FIG. 7 by the timer built in the CPU 43 at predetermined time intervals, first, the engine output control circuit is executed via the input circuit 41. A process of reading the throttle control mode that is being executed by 15 is performed (step S300). Since the engine output control circuit 15 outputs the throttle control mode currently being controlled to the output circuit 55, the constant speed traveling control circuit 10 can read the current throttle control mode by reading this signal. it can.

Subsequently, the read throttle control mode is discriminated (step S310), and particularly when the throttle control is not performed (in other cases), the auxiliary coefficient K used for calculating the drive amount of the constant speed traveling actuator 25. Then, a predetermined value Ka is set (step S320), and the process directly goes to "RTN" to end the present routine. On the other hand, when it is determined that the throttle control mode or the control mode for the high μ road is set, the auxiliary coefficient K is set to a value Kb larger than the predetermined value Ka (step S330), and the low μ is set.
If it is determined that the road throttle control mode is set, the auxiliary coefficient K is set to a value Kc larger than the value Kb (step S340), the routine goes to "RTN", and this routine ends.

By the above processing, the engine output control circuit 15 determines whether the road surface is a high μ road or a low μ road based on the slip ratio of the wheels or the state of the switch 57, and the second throttle valve is operated in the throttle control mode according to this. When the opening degree of 22 is controlled, the constant speed traveling control circuit 10 sets the auxiliary coefficient K when obtaining the drive amount of the constant speed traveling actuator 25 to a value according to the throttle control mode. Therefore, when the throttle control mode corresponding to the low μ road is selected, similarly to the case where the gain G is set to a large value in the calculation of the drive amount D in the constant speed traveling control routine shown in FIG. Since the drive amount D is set to a larger value than the conventional value, even if the vehicle speed changes due to a disturbance such as a gradient, the fluctuation of the vehicle speed can be suppressed to be small. Also,
The vehicle speed can be returned to the target speed in a short time.

Although the auxiliary coefficient K is changed to a large value in this embodiment, the drive amount is changed by changing the initial opening SA in the equation (2) and the correction coefficient C in the equation (3) to a large value. It is also possible to correct to a larger value. It is also possible to temporarily correct the target vehicle speed Vt by changing it to a large value.

The embodiment of the present invention has been described above.
The present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention.

For example, in the embodiment, the circuit for controlling the constant speed running and the circuit for controlling the engine output are separately provided, but a single control circuit may be used. When it is performed by a single control circuit, a program for constant speed traveling control and a program for engine output control are run by, for example, time division processing, and as a result, both processing can be realized.

Further, the structure for controlling the intake air amount is not limited to the one using the throttle valve, and any structure such as a throttle shape may be adopted. Further, the actuator is not limited to the motor, and various types such as a rotary solenoid, a linear solenoid, and an actuator using air pressure can be used. As for changing the opening degree of the actuator and the characteristics of the output of the internal combustion engine, other than using the sub-throttle valve, as in the embodiment,
It can also be applied to control for suspending a part of a plurality of cylinders, control by ignition timing, and the like. Even if some cylinders are deactivated, the change in the engine output with respect to the drive amount of the throttle valve becomes gradual. Therefore, the drive amount is corrected to a large value to improve the control characteristics of the constant speed traveling control. be able to.

Further, a linkless throttle is constructed in which the operation amount of the accelerator pedal is detected by a sensor, the drive amount is obtained from the operation amount of the accelerator pedal by referring to a table, and the opening amount of the throttle valve is controlled by this drive amount. In this case, by preparing a plurality of these tables, it is possible to realize a plurality of throttle control modes with a single throttle valve. In this case, if a configuration is adopted in which constant-speed traveling control is performed by converting into the operation amount of the accelerator pedal, it is easy for the vehicle speed to change due to disturbance in the throttle control mode for low μ roads. The configuration is the same as that described above using the throttle valve. Even in such a case, the same effect can be obtained by applying the present invention and increasing the gain or the like when converting the operation amount of the accelerator pedal.

In the above embodiment, as the physical quantity to be controlled,
Although only the vehicle speed is taken up, needless to say, the physical quantity may be any quantity as long as the physical quantity is influenced by the output of the internal combustion engine and is a controllable quantity related to vehicle running. Examples of such physical quantities include physical quantities such as the speed and acceleration of an automatically traveling vehicle, the driving speed of an in-vehicle pump or generator driven by an in-vehicle internal combustion engine as a drive source, various quantities in power train control, and the like.

[0049]

As described above, in the internal combustion engine control device of the present invention, when the physical quantity is controlled in a state where the output characteristics of the internal combustion engine EG are different, the drive amount determination / correction means provided in the actuator control means M3. In the state where M4 is changed to the relationship in which the output of the internal combustion engine EG is slightly affected by the change in the drive amount, the relationship between the drive amount of the actuator AC and the output of the internal combustion engine is changed when determining the drive amount. Increase the drive amount. Therefore, the drive amount of the actuator AC is determined so as to compensate for the characteristic of the output of the internal combustion engine EG, and the control of the physical amount is improved as compared with the case where the drive amount determination correction means M4 is not acted. As a result, the fluctuation of the controlled physical quantity becomes small, and the time until the fluctuation is corrected becomes short.

For example, when the constant speed traveling control is performed by controlling the intake air amount, the delay of the vehicle speed control can be reduced and the vehicle speed can be reduced by correcting the drive amount of the actuator that controls the intake air amount. As the vehicle speed decreases, the vehicle speed returns to the target vehicle speed in a short time, which is a remarkable effect.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of the present invention.

FIG. 2 is a schematic configuration diagram of an internal combustion engine controller that is an embodiment of the present invention.

FIG. 3 is a graph showing a relationship between a first throttle valve opening α and an output torque Q of an engine.

FIG. 4 is a flowchart showing a gain setting processing routine executed by the constant speed traveling control circuit 10.

FIG. 5 is a flowchart showing a constant speed traveling control routine that is also executed by the constant speed traveling control circuit 10.

FIG. 6 is a graph showing how vehicle speed control deviates due to a change in road gradient.

FIG. 7 is a flowchart showing an auxiliary coefficient setting processing routine executed by the constant speed traveling control circuit 10 in the second embodiment.

FIG. 8 is a graph for explaining the relationship between changes in the first throttle valve opening α and changes in the engine output torque Q in a plurality of throttle control modes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Intake manifold 3 ... Intake passage 5 ... Intake air adjusting mechanism 10 ... Constant speed running control circuit 15 ... Engine output control circuit 20 ... Accelerator pedal 21 ... First throttle valve 22 ... Second throttle valve 25 ... Constant speed Travel actuator 27 ... Throttle actuator 31 ... First throttle valve opening sensor 32 ... Second throttle valve opening sensor 41 ... Input circuit 43 ... CPU 45 ... Output circuit 47 ... Vehicle speed sensor 49 ... Constant speed travel set switch 51 ... Input circuit 53 ... CPU 55 ... Output circuit 57 ... Switch 59 ... Control mode display indicator AC ... Actuator AC1 ... First actuator AC2 ... Second actuator EG ... Internal combustion engine L21 ... Characteristic specifying means L22 ... Second throttle opening control means M1 ... intake Varying means M2 ... engine characteristic changing means M3 ... actuator control means M4 ... drive quantity determining correction means N1 ... vehicle speed detecting means N2 ... target vehicle speed setting means N3 ... vehicle speed responsive control means

Claims (3)

[Claims] 1. An intake air amount changing means for changing an intake air amount of an internal combustion engine driven by an actuator, an internal combustion engine characteristic changing means for changing a relation of an output change of the internal combustion engine with respect to a driving amount of the actuator, and a vehicle speed. , And an actuator control means for determining a drive amount of the actuator in a direction in which a controllable physical quantity that is influenced by the output of the internal combustion engine and is related to vehicle travel, such as acceleration, approaches a target value. In the state where the relationship between the drive amount and the internal combustion engine output is changed by the internal combustion engine characteristic changing means to a relationship in which the output of the internal combustion engine is slightly affected by the change in the drive amount, the driving means An internal combustion engine control device comprising a drive amount determining / correcting means for increasing the drive amount when determining the amount. 2. The internal combustion engine controller according to claim 1, further comprising a vehicle speed detecting means for detecting a vehicle speed and a target vehicle speed setting means for setting a target vehicle speed, wherein the intake air amount varying means is an actuator. A throttle valve whose opening is adjusted, and the actuator control means includes a vehicle speed response control means that applies feedback control to the actuator in a direction to reduce the deviation between the vehicle speed and the target vehicle speed. Internal combustion engine control device provided. 3. The internal combustion engine controller according to claim 1, wherein the intake air amount varying means has a first throttle valve whose opening degree is adjusted by a first actuator, and an opening degree is adjusted by a second actuator. The internal combustion engine characteristic changing means includes a characteristic specifying means for specifying a characteristic of the throttle valve opening, which is a relationship between the first throttle valve opening and the internal combustion engine output, and an actual internal combustion engine characteristic changing means. A second throttle valve opening degree is detected, and a second throttle valve opening degree with respect to the first throttle valve opening degree is controlled so that the output of the internal combustion engine has the specified characteristic.
Throttle valve opening control means, and the drive amount determination / correction means compensates the drive amount of the second actuator in accordance with the throttle valve opening characteristic realized by the internal combustion engine characteristic changing means. Internal combustion engine controller.