JPS6316145A - Engine control device - Google Patents

Abstract

PURPOSE:To obtain the same drivability in the whole speed area without being affected by traveling resistance by making the changing speed of engine output control with respect to the same acceleration changing quantity higher the higher is a vehicle speed at the time of controlling said engine output in accor dance with an acceleration controlling quantity. CONSTITUTION:A control part 14 selects one map out of accelerator opening - target throttle opening maps 15 based on an accelerator opening alpha from an accelerator opening signal generating part 12 and the detected values of an information detecting part 13 for vehicle speed, gear position, etc. to determine a target throttle opening. And, based on the deviation between an actual throttle opening and the target throttle opening, and proportional, differential, and integral gains from a control gain determining part 18, a feedback control part 17 feedback controls a throttle opening. In this case, since the target throttle opening is set larger, the higher is the vehicle speed, the changing speed of the controlling quantity gets higher with the increase in vehicle speed.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention converts the amount of accelerator operation into an amount of electricity, and adjusts the engine output in accordance with this amount of electricity through an engine output adjustment means such as a throttle valve. The present invention relates to a control B2i arrangement of a vehicle engine.

(Conventional technology) Conventionally, the amount of accelerator operation is extracted as an electrical signal,
Various engine control devices have been proposed that operate actuators to open and close throttle valves based on this electrical signal.

Furthermore, there is also a known technique for improving driving performance by changing the relationship between the opening amount of the throttle valve and the amount of accelerator operation depending on the driving condition of the vehicle.
The throttle valve control device described in Publication No. 49 detects a factor that acts as a resistance to engine acceleration, that is, when the weight of the vehicle is large, and opens the throttle valve wide to ensure acceleration. There is.

By the way, when accelerating a vehicle, the running resistance increases as the vehicle speed increases, so there is a problem that the response of the engine output is slower at high speeds than at low speeds, deteriorating drivability.

(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 provide substantially the same drivability regardless of the vehicle speed.

(Structure of the Invention) The present invention provides an engine control device that controls engine output based on an accelerator operation amount, and includes means for increasing the rate of change of the engine output control amount for the same accelerator change amount as the vehicle speed increases. It is characterized by comprising:

(Effects of the Invention) According to the present invention, substantially the same drivability can be obtained over the entire speed range without being affected by running resistance.

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

Figure 1 shows 'control of the engine according to the present invention? 11 shows a system configuration diagram of devices, 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, 6 is a throttle opening sensor, 7 is a vehicle speed sensor, and 8 is a A DC motor serves as an actuator for the throttle valve 4. The control unit 5 receives the accelerator opening α indicating the amount of depression of the accelerator pedal, the throttle opening θ from the throttle opening sensor 6, the vehicle speed V from the vehicle speed sensor 7, the gear position from the transmission 3, etc. The control unit 5 is configured to generate output signals for driving the DC motor and control the throttle valve 4 based on these human input signals.

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 produce a predetermined throttle opening f(α) corresponding to the accelerator opening α are selected by a signal from the information f8 detection unit 13, and a throttle gain correction coefficient K (usually 1), a feed bank control section 17, and a J gain determination section 18 that determines control gains G, to G4 (described later) based on signals from the information detection section 13. And this control section 1
4, two operations are performed. That is, one map is selected from the plurality of α-f(α) maps 15, and the throttle gain correction coefficient K is determined to determine the target accelerator opening degree θ (θT=to*f(α)). These are a gain characteristic control operation and a feedback control operation for controlling the throttle valve 4.

In the latter feedback control operation, the control gains 00 to G4 of the feedback control section 17 are determined based on the signal from the information detection section 13.

This makes the transient response of the throttle opening θ variable. The output (OUT) from the feedback control section 17 is
The signal is applied to a servo drive section 19 corresponding to the DC motor 8 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.
Feedbanking to the l1 section. Control unit 1 in this case
The control rg operation performed by No. 4 is PID control (proportional operation + integral operation + differential operation) with a fast response speed, and the block diagram of this throttle control is shown in Fig. 3. The target throttle opening θ is determined, and the control formula for determining the target throttle opening θ7 is shown in the following equation +11, where G, , G, , ca
are constants that represent the proportional gain, integral gain, and differential gain, respectively.

10G, (θ7−θ)′−・−−−−−−−−・・−・−
(ll Since it is necessary to differentiate this +11 formula with respect to time in order to control it in units of time, if we differentiate θ7, we get θy""G+(θ, -〇)'102(θ, -θ)-1-
G, (θ1-θ)” −・−−−−−−−−−
・−(21 Here, the current throttle opening deviation θ, −θ=
EN, the throttle opening deviation in the previous control cycle is ENI, and the throttle opening deviation in the control cycle before the previous control cycle is EN2. From (2) 2, θr'
=G+'l' (EN EN 1)+G2*EN+Q
, * ((EN EN 1) (EN 1-EN2
)1 -G, * (EN ENI) + Gz'kEN+ Q,
*(EN 2 * EN 1 + EN 2) Next, FIG. 4 shows the flow of the main program for throttle control performed by the control unit 5 in the present invention.

First, in step 31, the system is initialized. Next, after performing interrupt permission processing in step 32,
In step 33, the relationship between the accelerator opening α and the throttle opening f(α) shown next to the L
Select one map. MAP A is transmission 3 in Figure 1.
This is a map showing the relationship between the accelerator opening α and the throttle opening f(α) when the gear position is, for example, neutral, reverse, or 1st to 3rd gear position. This is a map showing the relationship between the accelerator opening degree α and the throttle opening degree r(α) when the vehicle is in the 5th and 5th speed positions. Next, in step 34, the throttle opening f(α) for the Ansel opening α is determined from the map selected in step 33, and then in step 35
Read the ■-ρ map shown next to it, and find the throttle opening correction amount ρ from the vehicle speed ■. This ρ corresponds to running resistance and increases in proportion to vehicle speed V. Then in step 36 =
1, and in step 37, *f(α)+ρ is calculated for θa. In this way, the target throttle opening θ is determined, but since ρ is a value proportional to the vehicle speed V, even if the change in accelerator opening α is the same, the opening speed of the throttle valve will be greater than the vehicle speed V. The larger the speed, the faster it will be. Fig. 5 is a graph showing the relationship between the accelerator opening α obtained in this way and the target throttle opening θ1.When the vehicle speed is low or low speed ■1, it changes linearly along the straight line ○P. The target throttle opening θ7 becomes 100% when starting with the accelerator fully open, but
At medium speed ■2, the target throttle opening θ becomes 100% when the accelerator opening α is about 75%, and the relationship between the accelerator opening α and the target throttle opening θ changes along the broken line OQP. become. Furthermore, at high speed ■, the accelerator opening α is about 50% and the target throttle opening θ7 is 100%.
Therefore, the relationship between the accelerator opening degree α and the target throttle opening degree θ changes along the broken line ORP. Therefore, when the vehicle speed ■ is high, in the high throttle opening range, the target throttle opening θ changes with respect to the change in the accelerator opening α.
.

There is no change in , which is unfavorable in terms of responsiveness to the accelerator opening degree α. Therefore, in this embodiment, a straight line A as shown in FIG. 6 is set in step 38 of FIG. Even in the high throttle opening range, when the throttle opening α changes, consideration is given so that the target throttle distance θa always changes.

That is, in step 38 of FIG. 4, the value of A is determined from the throttle opening α, and in step 39, θ and A are compared, and θ
When A≦A, the value of θ1 is adopted as is, but θ7>
If A, then θT=A is set in step 40.

Next, FIG. 7 shows the flow of an interrupt program for determining the amount of operation of the throttle actuator.

This program is executed every 10m5ec.

First, in step 51, interrupts are prohibited, and in the next step 52, the accelerator opening degree α, throttle opening degree θ, and gear position are read. Next, in step 53, a map shown nearby is read to determine a constant 60 that determines the control gain of the entire system depending on the vehicle speed (or gear position). Next, in step 54, the operation amount MN of the throttle actuator corresponding to the DC motor 8 in FIG.
) is calculated using the formula (PAD control). That is, E.N.
←θ, -θ MN←MN + G o ” (G l * (E N
-E N 1 )+c2*EN 10G, +k(EN-2*EN]+EN2)IENI ←
EN EN2←EN1 Also, for the next calculation, the current throttle opening deviation E
N is the previous throttle opening deviation ENI, and the previous throttle opening deviation ENI is the throttle opening deviation EN from the time before last.
2, the memory is shifted to 0, respectively. Next, the process proceeds to step 55, and the operation IMN+KMN (K
MN is an offset value) is output to the actuator.6 In this embodiment, the actuator is a DC motor, so the manipulated variable MN is converted into a voltage by a D/A converter and output. Then, in step 56, interrupts are enabled and this interrupt program is ended.

As is clear from the above explanation, the present invention is configured such that the rate of change of the engine output control amount for the same accelerator operation amount is made faster as the vehicle speed increases, so that the engine output control amount changes faster over the entire speed range without being affected by running resistance. The same drivability can be obtained with

In the above embodiment, a throttle valve is used as an adjusting means for adjusting the engine output in an automatic cycle engine in which the intake air amount, that is, the engine output is adjusted by the 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 the 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, Figures 5 and 6 are graphs showing the relationship between accelerator opening α and target throttle opening θ1, and Figure 7 is a flowchart of an interrupt program that determines the control amount of the throttle actuator. . l・-Engine 2・-・Clutch 3-Speed a
, 4--Throttle valve 5--Control unit 6--Throttle opening sensor 7--Vehicle speed sensor 8--DC motor

Claims (1)

[Claims] An engine control device for controlling engine output based on an accelerator operation amount, characterized in that the engine control device is equipped with means for increasing the rate of change of the engine output control amount for the same accelerator change amount as the vehicle speed increases. Control device.