JPS6316155A - Engine control device - Google Patents

Abstract

PURPOSE:To improve acceleration while relieving a clutch shock by forcedly controlling an engine as a power mode when both the down shift of a transmission and the stepping in of an accelerator are detected. CONSTITUTION:In a control part 14, the optimum map is selected out of plural maps 15 by a selecting/setting part 16 based on information on an engine condition and a vehicle traveling condition, etc. from a detecting part 13. And, by setting the increasing rate K of a throttle gain, a target throttle opening thetaT corresponding to an accelerator opening alpha is obtained. Further, a control part 17 carries out a feedback control based on control gains G0-G4 determined by the information of the detecting part 13. In this case, when both the down shift of a transmission and the stepping in the an accelerator are detected, the throttle gain is increased forcedly controlling an engine as a power mode. Thereby, a good acceleration can be obtained while relieving a shock at the time of connecting a clutch and, further, facilitating the connection of the clutch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides an engine control system that allows the engine output control mode to be selectively switched between power mode and economy mode depending on the driving situation. 'in device.

(Prior Art) Various types of vehicles have been proposed in the past that improve the running characteristics of a vehicle by switching the engine output control mode depending on the driving situation. For example, in Japanese Patent Application Laid-Open No. 59-74341, a plurality of different throttle opening characteristics are stored in advance for the accelerator opening, and the throttle valve is adjusted based on the Mero 5 Torr opening characteristic selected by a selection switch. An accelerator control device is disclosed in which the opening degree is controlled in accordance with accelerator operation. When equipped with selectable control modes like this, the control mode that focuses on output characteristics and increases the throttle control gain is generally called the power mode.
The control mode in which the throttle control gain is reduced with emphasis on fuel efficiency characteristics is called the economy mode.

Incidentally, in an M/T vehicle, opportunities for acceleration accompanied by downshifting of the transmission occur relatively frequently during driving. During acceleration like this, the driver usually indicates a request to obtain a relatively large acceleration force, and at such times, if the engine output mode mentioned above is economy, the driver's request is However, it was not possible to achieve the same acceleration as expected, and the driver had to switch to power mode at the same time, which was cumbersome. In addition, when performing such acceleration, first reduce the throttle opening to zero and depress the clutch pedal to disconnect the engine from the transmission, then downshift the gear from the neutral position, and at the same time press the accelerator. A series of actions is performed: depressing the pedal, opening the throttle valve, and accelerating. At this time, the engine rotation speed Ne, which had been the same as the clutch output shaft rotation speed Nc, becomes lower than the clutch output shaft rotation speed Nc due to the clutch disengagement due to the accelerator opening becoming zero. On the other hand, since the clutch output shaft is coaxial with the input of the transmission, its rotational speed Nc rapidly increases as the gear is downshifted, so that the difference from the engine rotational speed Ne becomes large.

Therefore, the clutch is connected while the accelerator pedal is depressed and the engine speed Ne is increased, but if the engine control mode is the economy mode at this time, the degree of increase in the engine speed Ne is small. Good acceleration characteristics cannot be obtained, and the driver feels a shock due to the large difference between the clutch output shaft rotation speed Nc and the engine rotation speed Ne when the clutch is engaged.
There was a problem in that skill was required to connect the clutch.

(Object of the Invention) In view of the above-mentioned circumstances, an object of the present invention is to provide an engine control device that can improve the acceleration performance during acceleration accompanied by downshifting and reduce the shock when the clutch is engaged as described above. do.

(Structure of the Invention) The present invention provides an engine control device capable of selectively switching an engine output control mode between a power mode and an economy mode, in which both a downshift of a transmission and depression of an accelerator are detected. In some cases, the engine is forcibly controlled in the power mode.

(Effects of the Invention) According to the present invention, since the throttle gain becomes large during acceleration accompanied by a downshift, the engine speed Ne rises quickly, good acceleration performance is obtained, and the shock when the clutch is engaged is reduced. This has the advantage of making the clutch connection easier.

(Example) An example of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a system configuration diagram of an engine control device according to the present invention, in which 1 is an engine, 2 is a clutch, 3 is a transmission, 4 is a throttle valve, 5 is a control unit consisting of a microcomputer, and 6 is a throttle opening. The sensors include a vehicle speed sensor 7, an engine rotation speed sensor 8, and a DC motor 9 as an actuator for the throttle valve 4.

The control unit 5 receives signals from the mode selector switch, accelerator opening α indicating the amount of depression of the accelerator pedal, throttle opening θ from the throttle opening sensor 6, vehicle speed ■ from the vehicle speed sensor 7, and the transmission 3. Signals indicating the gear position from the engine, the engine speed Ne from the engine speed sensor 8, etc. are input, and the control unit 5, based on these input signals,
It is configured to generate an output signal for driving the DC motor and control the throttle valve 4.

FIG. 2 is a diagram illustrating the basic configuration and operation of the throttle control system according to the present invention. When the driver depresses the accelerator pedal 11, the accelerator opening signal generator 12 detects the accelerator opening α. , generates a signal corresponding to this accelerator opening degree α. In addition, the information detection unit 13
detects the vehicle's engine condition, surrounding conditions, etc., and generates signals to alert these conditions. 1st
The control section 14 corresponding to the control unit 5 in the figure is
A plurality of maps 15 that generate a predetermined throttle opening f(α) corresponding to the accelerator opening α are selected by a signal from the information detection unit 13, and a throttle gain increase rate K (normally 1) a section 16 for setting 1);
It consists of a feedback control section 17 and a control gain determination section 18 that determines control gains G0 to GaC (described later) based on the signal from the information fullf detection section I3. Two operations are performed in this control section 14. That is, one map is selected from the plurality of α-f(α) maps 15, and the throttle gain increase rate K is determined to determine the target accelerator opening degree (8 points (θa *fCα)) gain characteristic. These are a control operation and a feedback control operation for controlling the throttle valve 4. In the latter feedback control operation, the signal from the information detection section 13 causes
Control gains G0 to G4 of the feedback control section 17 are determined. This makes the transient response of the throttle opening θ variable. Output from the feedback control section 17 (OU
T) is applied to a servo drive section 19 corresponding to the DC motor 9 in FIG. 1, and this servo drive section 19 drives the throttle valve 4. Further, a throttle opening signal generating section 20 corresponding to the throttle opening sensor 6 shown in FIG. 1 detects the actual throttle opening .theta. and feeds back the value of .theta. to the feedback control section. The control operation performed by the control unit 14 in this case is based on PID, which has a fast response speed.
It is a control (proportional action + integral action + differential action), and its block diagram is shown in FIG. With this throttle control,
The target throttle opening θa is determined based on the accelerator opening α, and the control formula for determining the target throttle opening θ7 is shown in equation [1] below. In addition, G+, Gz,
Gy is a constant 10 G that represents the proportional gain, integral gain, and differential gain, respectively! (θa θ)′ ・−−−
-m-------(1) Since it is necessary to control this ill2 in units of time, it is necessary to obtain a value differentiated with respect to time.

Differentiating θ, θT'=Gl(θ, -〇)'+GK(θ, -θ)+G3
(θ7−θ)“ −1−−−・−−−−1−・−・
−・・−(2) Here, let the current throttle opening deviation θa θ=EN, the throttle opening deviation in the previous control cycle be ENl, and the throttle opening deviation in the control cycle before the previous one be EN2, then +2 ) From 2, θT
'=Gl* (EN-ENI)+G, *EN+Ct*
((EN-ENI)-(ENI-EN2)1 =G, *(EN-ENI)+Gg'4'EN+Gz
” (EN-2*EN 1 +EN2)----・-・
(3) Next, FIG. 4 shows the flow of the main program for throttle control performed by the control unit 5 in the present invention. First step 3
1, initialize the system. Next, in step 32, an interrupt permission process is performed, and then in step 33, a target throttle opening degree θ7 for the accelerator opening degree α is determined.

Next, FIG. 5 shows the flow of an interrupt program for determining the amount of operation of the throttle actuator.

This program is executed every 30III seconds.

First, in step 5I, interrupts are prohibited, and in the next step 52, the accelerator opening degree α, throttle opening degree θ, and gear position are read. Then, in step 53, D in FIG.
The operation IMN of the throttle actuator corresponding to the C motor 9 is calculated using the above-mentioned formula (3) (PID
control). That is, EN←θ, -〇MN-MN + Go*(G+ *(EN EN
1)+Gz*EN +Gi*(EN-2+kEN1+EN2))ENI←E
N ENZ &-ENI Note that Go is a constant that represents the control gain of the entire system, and is normally set to Go''l.For the next calculation, the current throttle opening deviation EN is set to the previous throttle opening. The previous throttle opening deviation ENI is memory-shifted to the previous throttle opening deviation EN2 to the deviation ENI. Next, the process proceeds to step 54, where the manipulated variable MN calculated in step 53 is output to the actuator. Since the actuator is a DC motor, the amount of operation M
N is converted into a voltage by a D/A converter and output.

Then, in step 55, interrupts are enabled and this interrupt program is ended.

FIG. 6 shows an example of a control flow for determining the target throttle opening degree θ in step 33 of FIG. If it is in the economy mode, the gear shift position of the transmission 3 is detected in step 101. When the gear shift position is at the neutral position or the reverse position, the process proceeds to step 110, where the throttle gain increase rate K is set to 1. When the gear has been shifted to the forward position, the process proceeds to step 102, where the gear shift position before downshifting is stored as, for example, "shift 1".The gear position after the next gear shift is set as "shift 2", and in step 103, the shift I is and shift 2.

And if a shift or down is performed, step 10
Proceed to step 4, set the downshift flag, then step 1
Proceed to step 06. If shift amplification is performed, set down the shift down flag in step 105 and then proceed to step 10.
If there is no change in the shift position, the process directly proceeds to step 106. In step 106, the shift position "shift 2" after the gear change is stored in place of "shift 1."

Then, in step 107, it is determined whether or not the accelerator has been depressed, and if the determination result is YES, step 10
Determine whether the downshift flag is set at step 8,
Only when it is determined that a flag should be raised, that is, when an acceleration accompanied by a downshift is detected,
In step 109, the throttle gain increase rate K is set to a predetermined value ε (ε>1), the engine control mode is switched to power mode, and the process proceeds to step 111. Note that if the determination result in step 100 is power mode, step 109 is immediately performed. Proceed to. Further, when it is determined in step 107 that the accelerator is not depressed, or that the downshift flag is not set in step 108, the process moves to step 110 and the throttle gain increase rate is set to 1. Proceed to step 111. In step 111, for example, the seventh
As shown in the figure, accelerator opening α and throttle opening f(α
) Select one map from multiple maps that shows the relationship between the map and the map. In FIG. 7, the straight line A is the gear shift a3 in FIG.
This is a map showing the relationship between the accelerator opening α and the throttle opening f(α) when the gear position is neutral, reverse, or 1st to 3rd gear. Songs wAB and C are maps when the gear position is 4th and 3rd gear, respectively. The map is shown when the vehicle is in 5th gear. When the gear position is 4th or 5th, the driving force of the tires is small and the running resistance is large, so
In step 112, the gain of throttle opening f(α) with respect to accelerator opening α is increased, the accelerator opening α is increased according to the map selected in step 111.
7) The value of the throttle opening f(σ)m is determined, and in step 113, the target throttle opening θ is determined by multiplying this throttle opening f(α) by the throttle gain increase rate K.

FIG. 8 is an explanatory diagram showing temporal changes in gear position, clutch pedal operation amount, engine rotational speed Ne, clutch output shaft rotational speed Nc, and throttle opening degree θ during acceleration accompanied by downshifting. When the throttle gain is increased when both the aircraft downshift and the accelerator depression are detected (K-ε, ε〉l)
), that is, the engine rotational speed Ne when the engine is controlled in the power mode sub-door is shown by a solid line, and the engine rotational speed when K=1, that is, the engine is controlled in the economy mode, is shown by a broken line. As is clear from Fig. 8, when the throttle gain is large, the acceleration is large, and since the difference ΔN between the clutch output shaft rotation speed Nc and the engine rotation speed when the clutch is engaged is small, the clutch engagement shock is also small. On the other hand, when the throttle gain is small, the acceleration performance is small and ΔN is large, so the clutch engagement shock is also large.

In the above embodiment, the engine control mode is changed by changing the throttle gain, but the air-fuel ratio may also be changed.

In the above embodiment, a throttle valve is used as an adjusting means for adjusting engine output in an automatic cycle engine in which the intake air amount, that is, output is adjusted by a throttle valve. However, the output adjustment means in the present invention is not limited to the throttle valve as in the above embodiment, but may be any means that changes and controls factors that significantly contribute to engine output. For example, in the case of a diesel engine whose output basically changes depending on the amount of fuel injected into the cylinder,
The fuel injection amount control device may be used as an output adjustment means.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of an engine control device according to the present invention, FIG. 2 is an explanatory diagram of the operation of a throttle control system,
Figure 3 is a block diagram of the throttle control system, Figure 4 is a block diagram of the throttle control system.
The figure is a flowchart of the main program, Figure 5 is a flowchart of an interrupt program that determines the control amount of the throttle actuator, Figure 6 is a flowchart for determining the target throttle opening, and Figure 7 is the #apple throttle for the accelerator opening. FIG. 8 is a diagram for explaining the present invention in detail. 1--Engine 2--Clutch 3--Speed change fi 4--Throttle valve 5-Control unit 6-Throttle opening sensor 7--Vehicle speed sensor 8--Engine speed sensor 9--DC motor

Claims (1)

[Claims] In an engine control device that can selectively switch the engine output control mode between a power mode that emphasizes output and an economy mode that emphasizes fuel efficiency, when both a downshift of the transmission and depression of the accelerator are detected, An engine control device comprising means for forcibly controlling the engine in the power mode.