JP2773552B2 - Total control system for traction and differential limiting torque - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction and differential limiting torque control system applied to a vehicle equipped with both a traction control system based on throttle valve opening and closing control and a differential limiting torque control system.

[0002]

2. Description of the Related Art Conventionally, as a vehicle throttle control device, for example, a device disclosed in Japanese Patent Application Laid-Open No. 62-45944 has been known.

In this conventional source, a second throttle valve, which can be opened and closed from the outside, is provided in series with an intake passage of an engine in addition to a first throttle valve interlocked with an accelerator operation, and when a throttle control condition is satisfied, that is, When the driving wheel slip exceeds the throttle control threshold value, the second throttle valve is controlled in three modes of opening, closing, and holding according to the driving wheel slip occurrence state, and the engine output is controlled to be reduced. A technique for suppressing wheel slip is disclosed.

[0004]

However, in such a conventional vehicle throttle control device, the throttle closing speed is kept constant when the throttle valve is closed in the throttle control for suppressing the driving wheel slip. When the throttle valve is opened, the throttle opening speed is controlled to be lower as the deviation between the driving wheel speed and the driven wheel speed is larger. Therefore, on a low friction coefficient road, the hunting of the control is performed by the high throttle valve opening speed. And the convergence and stability of the drive wheel slip are deteriorated.
On the road with a high friction coefficient, the first throttle valve linked with the accelerator operation is not effective immediately after the closing speed of the throttle valve is high and the throttle control is started, so that the accelerator control region of the driver is narrow and the acceleration is impaired.

Therefore, the present applicant has filed a Japanese Patent Application No. Hei 3-1233.
According to the specifications and drawings of No. 7, the convergence and stability of the drive wheel slip are achieved when traveling on a road with a low friction coefficient, and the accelerator control area of the driver is expanded when traveling on a road with a high friction coefficient to ensure acceleration. The road friction coefficient is determined by detecting the lateral acceleration and the longitudinal acceleration, and when it is determined that the road is a low friction coefficient road, the closing speed of the throttle valve is increased to a high speed and the opening speed is reduced to a high friction coefficient road. When it is determined that the throttle valve is closed, a solution is proposed in which the closing speed of the throttle valve is reduced and the opening speed is increased.

A differential limiting torque control system is mounted on a vehicle equipped with this control system, and the differential limiting torque control system has a large throttle opening in order to achieve both turning acceleration and accelerator control. It is assumed that the control for increasing the differential limiting torque is performed as the lateral acceleration increases.

In the case of this combined system, the high μ near the limit is used.
During road running, when the recovery control for opening the throttle valve is performed on the throttle control side, the opening speed of the throttle valve is high, so if this throttle valve opening information is directly taken in on the differential limiting torque control system side,
The differential limiting torque will increase sharply.

As a result, especially at the time of turning at a high lateral acceleration, a sudden increase in the driving torque transmitted to the turning outer wheel side may be caused, and the stability of the vehicle may be impaired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and is different from a traction system applied to a vehicle equipped with both a traction control system by opening and closing control of a throttle valve and a differential limiting torque control system. An object of the present invention is to achieve both stability and acceleration by accelerator control when traveling on a road with a high friction coefficient near the limit in a comprehensive control device with dynamic limiting torque.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a total control system for traction and differential limiting torque according to the present invention has a differential law having a control law that increases the differential limiting torque as the throttle opening increases. As a control throttle opening used in the limiting torque control system, at least when the throttle valve is driven in the opening direction by the recovery control, a throttle opening setting based on an opening speed slower than the actual opening speed is set. Means were provided.

That is, as shown in the claim correspondence diagram of FIG. 1, a valve actuator b for opening and closing the throttle valve a independently of the accelerator operation, and an acceleration detecting means c for detecting a lateral acceleration and a longitudinal acceleration. A traction control system e having a traction control means d having a control law for increasing the recovery opening speed of the throttle valve a as the value becomes larger, and an increase / decrease of the differential limiting torque by an external command to the differential limiting torque applying means f. A differential limiting torque control system i having a differential limiting actuator g for performing control and differential limiting torque control means h having a control law for increasing the differential limiting torque as the throttle opening increases, As the control throttle opening used in the torque control system i, at least the throttle valve a When driven in the opening direction by the cover control and a control for the throttle opening setting means j for setting the throttle opening by the opening speed that is slower than the actual opening speed.

[0012]

When the traction control system e performs the recovery control due to the convergence of the acceleration slip, for example, during straight running or turning running on a road with a high friction coefficient, acceleration detecting means for detecting lateral acceleration and longitudinal acceleration. A command to open the throttle valve a at a high opening speed is output from the traction control unit d to the valve actuator b based on a control law that increases the recovery opening speed of the throttle valve a as the acceleration detection value from c increases. .

On the other hand, in the controlled differential limiting torque control system i having a control law of increasing the differential limiting torque as the throttle opening increases, the control throttle opening setting means j controls the differential limiting torque control. As the control throttle opening used in the system i, a throttle opening based on an opening speed slower than the actual opening speed is set when at least the throttle valve a is driven in the opening direction by the recovery control. For this reason, during the throttle recovery control, the differential limiting torque
, A control command for increasing the differential limiting torque in accordance with the control throttle opening set is output.

Therefore, at the time of the throttle recovery control, the control for suppressing the increase of the differential limiting torque is performed at the control throttle opening lower than the actual throttle opening of the throttle valve a, and the differential limiting torque is reduced. By avoiding a sudden increase, vehicle stability is ensured, especially during high lateral acceleration turning.

Further, by using the throttle opening for control on the differential limiting torque control system i side, the acceleration performance by the differential limiting torque control is impaired, but the traction control system e side having the same purpose is used. In the above, the control law for increasing the recovery opening speed of the throttle valve a as the acceleration detection value from the acceleration detection means c for detecting the lateral acceleration and the longitudinal acceleration is maintained as it is, so that the acceleration by the accelerator control is secured. Will be.

That is, when the two control systems simultaneously perform control operations to achieve the same purpose, control interference that results in excessive control occurs.
The throttle control side is left as it is, and the differential limit control side suppresses excess control, thereby adjusting both control systems.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration will be described. FIG. 2 is an overall control system of a rear-wheel drive vehicle to which the integrated control device for traction and differential limiting torque according to the embodiment of the present invention is applied.

As the traction control system, a combined system of TCS throttle control for controlling the motor throttle opening degree and TCS brake control for controlling the brake pressure of the rear wheels so that the rear wheel slip ratio is within the optimum allowable range is mounted. Have been.

Further, as a differential limiting torque control system, a system for controlling the differential limiting torque by controlling the hydraulic pressure of the differential limiting clutch is mounted.

The TCS throttle control is performed by a throttle motor 3 (corresponding to a valve actuator) for opening and closing a second throttle valve 2 (corresponding to a throttle valve) provided in series with a first throttle valve 1 which operates in conjunction with an accelerator pedal. ) Is performed by applying a motor drive current from the throttle control controller 5 based on a control command from the LSD / TCS controller 4.

The TCS brake control is performed by outputting a control command from an LSD / TCS controller 4 to a TCS brake actuator 9 for generating a control oil pressure based on an oil pressure from an external oil pressure source 8 in left and right wheel cylinders 6 and 7. Done.

The differential limiting torque control is performed by an LSD hydraulic unit 12 (corresponding to a differential limiting actuator) which generates a clutch control hydraulic pressure for a differential limiting clutch 11 (corresponding to a differential limiting torque applying means) built in the differential 10. ) Is performed by outputting a control command from the LSD / TCS controller 4.

The LSD / TCS controller 4 includes:
And right front wheel speed V _{A NR} from front right sensor 13, and the left front wheel speed V _ANL from front left sensor 14, and the right rear wheel speed V _NAR from the rear wheel right sensor 15, the left from Kowahidari sensor 16 Rear wheel speed V
_NAL and lateral acceleration sensor 17 (corresponding to acceleration detection means)
And the lateral acceleration Y _G from a longitudinal acceleration X _G from the longitudinal acceleration sensor 18 (corresponding to the acceleration detecting means), a switch signal from the TCS ON / OFF switch 19, a switch signal from the brake lamp switch 20, the throttle The first throttle opening θ _1, the second throttle opening θ _{2, and the} like are input from the controller 5.

The LSD / TCS controller 4 outputs an ABS control command to the ABS actuator 21 in addition to the above output.
A lighting command is output to the indicator 22, a lighting command is output to the TCS warning lamp 23 when TCS fails, a lighting command is output to the ABS warning lamp 24 when ABS fails, and a lighting command is output to the LSD warning lamp 25 when LSD fails. You.

The throttle control controller 5 is a control circuit mainly including a throttle motor drive circuit.
The first throttle opening θ ₁ from the throttle sensor 26
, The second throttle opening θ ₂ from the second throttle sensor 27 is input.

In this control system, as a peripheral system, as shown in FIG.
An engine centralized electronic control system with CS, an automatic transmission control system with A / T controller, and a constant speed cruise control system with ASCD actuator and ASCD controller are provided.

Next, the operation will be described.

(A) TCS throttle opening speed calculation processing FIG. 3A is a flowchart showing a TCS throttle opening speed calculation routine performed by the LSD / TCS controller 4.

[0030] At step 30, the acceleration X _G and the lateral acceleration Y _G front and rear are input.

[0031] At step 31, the opening speed set gain K _G1 decide TCS throttle opening speed V _TO based on the longitudinal acceleration X _G is obtained.

The opening speed setting gain K _G1 is _calculated as shown in FIG.
As shown in, the small constant value when the longitudinal acceleration X _G is less than X _GL, longitudinal acceleration when the longitudinal acceleration X _G exceeds X _GL
Is set by the higher becomes the value in proportion to the magnitude of X _G.

In step 32, it is determined whether or not the value of the lateral acceleration absolute value | Y _G | exceeds the low lateral acceleration set value Y _GL . When | Y _G |> Y _GL , the routine proceeds to step 33, where the throttle is opened. The speed V _TO is determined by the equation V _TO = K _G1 · | Y _G | + b.

When | Y _G | ≦ Y _GL , the _routine proceeds to step 34, where the TCS throttle opening speed V _TO is set to V _TO = V _TOMIN .

[0035] At step 35, TCS throttle opening speed V _TO calculated in step 33 whether V _TO> V _TOMAX is determined, when a V _TO> V _TOMAX is the V _TO = V _TOMAX in step 36 Is set.

[0036] At step 37, the value obtained in step 33 or step 34 or step 36 is set as the TCS throttle opening speed V _TO. That, TCS throttle opening speed V _TO, as shown in FIG. 4 (a) would be set to a high speed value larger the longitudinal acceleration X _G and the lateral acceleration Y _G.

(B) LSD throttle opening speed calculation processing FIG. 3B is a flowchart showing an LSD throttle opening speed calculation routine performed by the LSD / TCS controller 4.

As shown in FIG. 4B, the opening speed setting gain K _GD is given with a lower gain than the opening speed setting gain K _G1 , and the LSD throttle opening speed minimum value V _DOMIN
And the maximum value of the LSD throttle opening speed V _DOMAX are shown in FIG.
As shown in (2), the TCS throttle opening speed calculation process is different from the TCS throttle opening speed calculation process in that it is given a value lower than the TCS throttle opening speed minimum value V _TOMIN and the TCS throttle opening speed maximum value V _TOMAX .

In the processing itself, since steps 30 to 37 correspond to steps 40 to 47 as they are, a description of each step will be omitted.

By this processing, the LSD throttle opening speed V
_DO, as shown in FIG. 4 (a), similarly to the TCS throttle opening speed V _TO, but is set to a high speed value larger the longitudinal acceleration X _G and the lateral acceleration Y _G, the lateral acceleration Y _G In the front area,
It will be set at a lower speed than in the TCS throttle opening speed V _TO.

(C) Motor throttle opening control operation FIG. 4 is a flowchart showing the flow of the motor throttle opening control operation performed by the LSD / TCS controller 4 (corresponding to traction control means).

In step 70, each wheel speed sensor 1,
From 2, 3, 4 to right front wheel speed V _ANR , left front wheel speed V _ANL , right rear wheel speed
V _NAR and left rear wheel speed V _NAL are read.

In step 71, the vehicle speed V _MNA is calculated from the average value of the front right wheel speed V _ANR and the front left wheel speed V _ANL .

[0044] At step 72, the drive wheel average velocity V _{M AN} is calculated by the average value of the right rear wheel speed V _NAR and the left rear wheel speed V _NAL.

[0045] At step 73, the front and rear wheel average velocity [Delta] V _A by the difference between the drive wheel average velocity V _MAN and the vehicle speed V _MNA is calculated.

[0046] At step 74, the drive-wheel average velocity V _MAN and the vehicle speed V _MNA and the throttle control slip ratio S _S is calculated.

In step 75, the comparison between the vehicle speed V _MNA , the average front-rear wheel speed ΔV _A , and the throttle control slip ratio S _S obtained by the calculation is compared with the preset throttle control threshold map shown in step 76. Done.

In step 77, it is determined whether the result of comparison in step 75 is to hold the throttle open or to close the throttle.

[0049] If a result of determination that the throttle opening, the process proceeds to step 78, the throttle opening speed V _TO set in the routine shown in the loaded (a) in FIG. 3, the throttle in step 79 opening speed V _TO A command to open the second throttle valve 21 is output.

If the result of the determination is that the throttle is to be held, the routine proceeds to step 80, where a command to hold the valve opening of the second throttle valve 21 is output.

In the case of a decision result that the throttle is closed,
Proceeds to step 81, the throttle shutting speed V _TC is set to a low speed value larger the longitudinal acceleration X _G and the lateral acceleration Y _G (see Japanese Patent Application No. 3-12337) is read, step 8
The second throttle valve 21 is closed command is output at 2 in the throttle closing speed V _TC.

(D) Differential limiting torque control operation FIG. 6A is a flowchart showing the flow of the differential limiting torque control operation performed by the LSD / TCS controller 4 (corresponding to differential limiting torque control means). .

In step 50, the first throttle opening θ ₁ corresponding to the accelerator depression amount and the second throttle opening θ ₂ whose opening is controlled to be increased or decreased by the TCS throttle control.
And the lateral acceleration Y _G are read.

In step 51, the LSD control throttle opening θa set by the LSD control throttle opening calculation routine described later is read.

[0055] At step 52, the throttle opening sensing gain Ka according to the lateral acceleration Y _G is calculated. The throttle opening sensitivity gain Ka is given as a constant value in a low lateral acceleration range where the lateral acceleration Y _G is equal to or less than a predetermined value, and is gradually increased when the lateral acceleration Y _G exceeds the predetermined value.

In step 53, the throttle opening sensitivity torque Ta is calculated according to the LSD control throttle opening θa and the throttle opening sensitivity gain Ka. The throttle opening sensitivity torque Ta is given as a value that is zero until the LSD control throttle opening θa reaches a predetermined value, and gradually increases at an increasing ratio according to the throttle opening sensitivity gain Ka when the throttle opening θa exceeds the predetermined value.

In step 54, the throttle opening-sensitive torque Ta calculated in step 53 is converted into a current i for obtaining the torque Ta.

In step 55, the current i obtained in step 54 is output to the LSD hydraulic unit 12.

FIG. 6B is a flow chart showing a routine for calculating the throttle opening θa for LSD control (corresponding to control throttle opening setting means).

In step 60, it is determined whether or not TCS throttle control is not performed.

[0061] At step 61, the absolute value of the difference between the LSD control throttle opening θa and the first throttle opening theta ₁ whether less than the set value a is determined.

[0062] At step 62, LSD control throttle opening θa whether the first throttle opening degree θ less than ₁ is determined.

In step 63, the first throttle opening θ
₁ is set as the LSD control throttle opening θa.

[0064] In step 64, shown in FIG. 3 (b) of LSD throttle opening speed calculated on the throttle opening which is calculated in accordance with the LSD throttle opening speed V _DO obtained in calculating routine LSD control throttle opening θa Is set as

In step 65, the first throttle opening θ
₁ and whether the difference between the second throttle opening theta ₂ is greater than zero is determined.

In step 66, θ _MX = θ ₁ is set, and θ _MN = θ ₂ is set. Here, θ _MX represents θ _MAX , and θ _MN represents θ _MIN .

In step 67, θ _MX = θ ₂ is set, and θ _MN = θ ₁ is set.

In step 68, it is determined whether or not the throttle opening θa for LSD control is equal to or _larger than the minimum throttle opening θ _MN .

In step 69, the throttle opening minimum value θ _MN is set as the throttle opening θa for LSD control.

That is, as is clear from the time chart showing the setting status of the LSD control throttle opening θa in FIG. 7, when the TCS throttle control is ON, the first throttle opening θ ₁ is set in steps 65 to 67 in step S67. The second throttle opening θ ₂ is selected low, and θ ₁ <θ
_If it is ₂ , the first throttle opening θ ₁ is determined in step 69.
, The throttle opening θa for LSD control is set. When θ ₁ ≧ θ ₂ holds and the second throttle valve 2 is held or controlled in the closing direction, the throttle opening θa for LSD control is set in step 69 following the second throttle opening θ _2. You. Further, when the second throttle valve 2 is controlled in the opening direction by the recovery control, the routine proceeds to step 64, where the LSD throttle opening speed is controlled.
It is set to LSD control throttle opening θa corresponding to V _DO.

When the TCS throttle control is OFF, the control is turned OFF, but when the LSD control throttle opening θa has not caught up with the first throttle opening θ ₁ , that is, NO is determined in step 61. The throttle opening θa for LSD control corresponding to the LSD throttle opening speed V _DO is set only when YES is determined in step 62, otherwise, the first throttle opening θ _{1 is set.}
Is directly set as the LSD control throttle opening θa.

(E) When traveling on a road with a low friction coefficient When traveling straight or turning on a road with a low friction coefficient, the lateral acceleration Y _G detected by the lateral acceleration sensor 17 is also detected by the longitudinal acceleration sensor 18. The acceleration _XG also has a small value.

[0073] Thus, in TCS throttle control side is set to high speed of the throttle closing speed V _TC, would be set to the low speed of the throttle opening speed V _TO, sufficient reduction of the engine torque is achieved, the driving wheel slip High convergence and stability are achieved.

[0074] On the other hand, the differential limiting torque control side, by the lateral acceleration Y _G is smaller, small throttle opening sensing gain Ka, also the throttle opening θ for LSD control
a second throttle opening degree is low by the throttle control theta ₂
In many cases, the differential limiting torque is hardly applied. However, if there is a difference in rotational speed between the left and right rear wheels on a split μ road or the like, the difference between the left and right rotational speeds is suppressed by performing control to apply a differential limiting torque according to the difference in left and right rotational speeds. Will be secured.

(F) When traveling on a road with a high friction coefficient At the time of turning acceleration on a road with a high friction coefficient, the lateral acceleration sensor 1
The lateral acceleration Y _G detected by the sensor 7 is also the longitudinal acceleration sensor 18.
The longitudinal acceleration X _G also large value detected by.

Therefore, on the TCS throttle control side, the throttle closing speed V _TC is set to the low speed, and the throttle opening speed V _TO is set to the high speed. When a driving wheel slip occurs, the throttle closing speed V _{TC is set.} Is low speed, the first throttle valve 1 works effectively with the accelerator operation for a while even after entering throttle control, and when the drive wheel slip converges, the throttle opening speed _VTO becomes high. As a result, the effect of the first throttle valve 1 is ensured with good response from the convergence of the drive wheel slip, and the accelerator control area of the driver is expanded, and the acceleration performance is not impaired.

[0077] On the other hand, the differential limiting torque control side, by the lateral acceleration Y _G is large value, large throttle opening sensing gain Ka is, the throttle recovery control, the second
When the throttle opening θ ₂ increases, if the second throttle opening θ ₂ is used as it is as the LSD control throttle opening θa, the differential limiting torque rapidly increases.

However, when the second throttle valve 2 is controlled in the opening direction by the recovery control, the throttle opening θa for LSD control corresponding to the LSD throttle opening speed V _DO lower than the TCS throttle opening speed V _TO must be set. Thus, control is performed in which an increase in the differential limiting torque is suppressed, and since the differential limiting torque does not increase abruptly, vehicle stability is ensured, especially during high lateral acceleration turning.

As described above, when the two control systems of the TCS throttle and the differential limiting torque simultaneously perform control operations to achieve the same purpose of acceleration, control interference resulting in excessive control occurs. To cope with this control interference, the TCS throttle control side is left as it is, and the differential control torque control side suppresses excessive control, thereby adjusting both control systems.

As described above, in the embodiment, in the integrated control system of the traction by the opening / closing control of the throttle valve and the differential limiting torque, the control for increasing the differential limiting torque as the throttle opening increases. as a control a throttle opening θa used in the differential limiting torque control system with law, throttle the calculated when the second throttle valve 2 is driven by the recovery control in the opening direction which is slower than the actual throttle opening speed V _tO set the control throttle opening θa by using the opening speed V _DO, since the control throttle opening θa is the device for controlling to increase the differential limiting torque in a region of a predetermined value or more, the marginally high When traveling on a road with a friction coefficient, it is possible to ensure both stability and acceleration by accelerator control.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment. For example, in the embodiment, the example in which the throttle control is performed by the second throttle valve of the tandem throttle has been described. .

Further, in the embodiment, the example of the traction control system using both the throttle control and the brake control has been described, but the present invention can also be applied to a system using only the brake control.

[0083]

As described above, according to the present invention, in a total control system of the traction by opening and closing control of the throttle valve and the differential limiting torque, the differential limiting torque increases as the throttle opening increases. As a control throttle opening used in a differential limiting torque control system having a control law, a throttle opening based on a calculated opening speed that is lower than an actual opening speed at least when the throttle valve is driven in an opening direction by recovery control. The control throttle opening setting means is provided for setting the vehicle speed, so that when traveling on a road with a high coefficient of friction near the limit, it is possible to obtain both the effect of securing stability and the effect of ensuring acceleration by accelerator control. .

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram showing an overall control device for traction and differential limiting torque according to the present invention.

FIG. 2 is an overall view of a control system for a rear-wheel drive vehicle to which the integrated control device for traction and differential limiting torque according to the embodiment is applied.

FIG. 3 (a) is a flowchart showing a TCS throttle opening speed calculation routine performed by the LSD / TCS controller of the embodiment device, and FIG. 3 (b) is performed by the LSD / TCS controller of the embodiment device; 9 is a flowchart showing an LSD throttle opening speed calculation routine to be performed.

FIG. 4A is a throttle opening speed characteristic diagram,
FIG. 4B is an opening speed setting gain characteristic diagram.

FIG. 5 is a flowchart showing a flow of a motor throttle opening control operation performed by an LSD / TCS controller of the embodiment device.

FIG. 6 (a) is a flowchart showing a flow of a differential limiting torque control operation performed by an LSD / TCS controller of the embodiment device, and FIG. 6 (b) is a flowchart of an LSD control throttle opening. 9 is a flowchart illustrating a calculation routine.

FIG. 7 is a time chart showing a setting situation of a throttle opening for LSD control before and after TCS throttle control.

[Explanation of symbols]

 a throttle valve b valve actuator c acceleration detecting means d traction control means e traction control system f differential limiting torque applying means g differential limiting actuator h differential limiting torque control means i differential limiting torque control system

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁶ identification code FI F02D 29/02 311 F02D 29/02 311A 41/04 310 41/04 310G (58) Investigated field (Int. Cl. ⁶ , DB Name) B60K 41/00-41/28 B60K 23/04 B60K 28/16 F02D 29/00-29/06 F02D 41/00-41/40

Claims (1)

(57) [Claims] 1. A valve actuator for opening and closing a throttle valve irrespective of an accelerator operation, and a control for increasing a recovery opening speed of the throttle valve as an acceleration detection value from an acceleration detecting means for detecting a lateral acceleration or a longitudinal acceleration increases. A traction control system having traction control means having a law, a differential limiting actuator for increasing / decreasing a differential limiting torque by an external command to a differential limiting torque applying means, and a differential limiting as the throttle opening increases. A differential limiting torque control system having a differential limiting torque control means having a control law for increasing torque; and a throttle opening for control used in the differential limiting torque control system, at least a throttle valve is opened by recovery control. When driving at a lower speed than the actual opening speed The general control unit of the traction and differential limiting torque, characterized in that it comprises a control throttle opening setting means for setting a throttle opening by opening speed.