JP2011064130A - Engine speed control method, and control device for performing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform control so that engine speed does not exceed a predetermined limiting speed in every situation without causing an increase in cost. <P>SOLUTION: In this engine speed control method, an engine speed control device determines a target throttle opening 3 based on the detected engine speed 1 and outputs a drive signal for setting to the target throttle opening 3 to an electronic control throttle 5 arranged in the intake passage of an engine 6, thereby performing limit control so that the engine speed 1 does not exceed a target engine speed 2 as the predetermined limiting speed while adjusting a throttle opening 4. When the engine speed 1 exceeds the target engine sped 2, the throttle opening 4 at that time is stored. The target throttle opening 3 is determined so that the engine speed 1 is kept within the target engine speed 2 by using a predetermined mathematical expression based on the stored throttle opening 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an engine rotational speed control method and a control apparatus that performs the same, and more particularly, to an engine rotational speed control method that performs limit control so that an engine does not exceed a predetermined rotational speed, and a control apparatus that performs the same.

In the rotational speed control of an automobile engine, in general, limit control is performed so that the engine rotational speed does not exceed a predetermined speed (limit) in consideration of engine durability and the like. That is, when the engine speed exceeds a predetermined speed, the target throttle opening (θ _d ) is determined by reading from table data obtained experimentally in advance based on the value of the engine speed (N). Has been.

However, at this time, the target throttle opening (θ _d ) is obtained from only the information about the engine speed (N), and there is a problem that the speed limit cannot be kept constant due to engine load fluctuation. This is because even if the throttle opening is the same, the engine speed varies depending on the load.

  In response to this problem, Japanese Patent Laid-Open No. 2000-104617 discloses that the engine speed does not exceed a predetermined speed limit while the parameter setting unit changes the parameter based on the determination result by the engine load state determination unit. An engine speed control device for controlling the engine has been proposed, and in addition to the engine speed, engine load data detected by a means for detecting a neutral state, a means for detecting an engaged / disengaged state of a clutch, a means for detecting a gear position, etc. Can be used to cope with engine load fluctuations.

  However, newly arranging the sensors constituting the engine load state determination means in addition to the engine rotation speed detection means leads to an increase in system manufacturing cost. For this reason, it has been desired to develop a technology that enables engine speed limit control to be performed at high speed and high accuracy without adding new components to the conventional system.

JP 2000-104617 A

  An object of the present invention is to solve the above-described problems, and it is an object of the present invention to enable control so that the engine rotation speed does not exceed a predetermined speed limit in any situation without causing an increase in cost. To do.

  In view of this, the present invention provides an engine rotational speed control device that determines a target throttle opening based on a detected engine rotational speed and outputs a drive signal to an actuator for opening and closing a throttle valve disposed in an intake passage of the engine. In the engine speed control method for executing limit control so that the engine speed does not exceed a predetermined speed limit while adjusting the throttle opening, the throttle at that time when the engine speed exceeds the speed limit The opening is stored, and the target throttle opening is determined using a predetermined mathematical formula based on the stored throttle opening so that the engine speed is within the speed limit.

  In this way, rather than simply determining the target throttle opening based on only the information on the engine speed, the throttle opening at the time when the detected engine speed exceeds the speed limit is used as a base, By calculating the target throttle opening so that the amount of intake air that falls within the speed limit is achieved, the engine load fluctuates without requiring the addition of new parts to detect the engine load condition. Even in such a case, the limit control can be sufficiently executed.

（但し、θ_dは目標スロットル開度、Ｎ_dは目標エンジン回転速度、Ｎはエンジン回転速度、eはエンジン回転速度の目標エンジン回転速度に対する誤差、ＡＰＳ_holはリミット制御起動条件成立時のアクセルペダル信号から求められた目標スロットル開度、Ｋ₁〜Ｋ₃は定数）である、ことを特徴としたものとすれば、高速高精度なリミット制御が可能なものとなる。 Also, the mathematical formula used in this engine speed control method is

(However, θ _d is the target throttle opening, N _d is the target engine speed, N is the engine speed, e is the error of the engine speed with respect to the target engine speed, and APS _hol is the accelerator pedal when the limit control activation condition is satisfied. If the target throttle opening obtained from the signal, K _{1 to} K ₃ are constants), high-speed and high-precision limit control is possible.

  Furthermore, in the engine speed control method described above, the target throttle opening determined by the mathematical formula is compared with the throttle opening by the input accelerator pedal signal, and the smaller one is output as the final target throttle opening. If it is characterized by, it is possible to make it difficult to impair the operability of the driver.

  Further, the throttle opening is adjusted by determining the target throttle opening based on the engine rotation speed and outputting a drive signal to the opening / closing actuator. A control device that performs limit control so that the engine speed does not exceed a predetermined speed limit, and includes a control program for performing the engine speed control method described above. Assuming that the control device is the above-described control device, the engine speed control method described above can be implemented simply by disposing it in the system.

  According to the present invention, the target throttle opening is determined so that it falls within the speed limit based on the throttle opening when the engine speed exceeds the speed limit. The speed can be controlled so as not to exceed a predetermined speed limit.

It is a functional block diagram of an engine speed limit control system according to the control method of the present invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows a functional block diagram of an engine rotational speed limit control system according to the engine rotational speed control method of the present embodiment. This control method actually implements an engine rotational speed control method described later. A control device (engine speed control device) having a control program for this purpose is automatically executed as a control subject.

  As described above, in the conventional engine speed control method, since the control device is a method for obtaining the target throttle opening degree from only the information on the engine speed, the speed limit cannot be kept constant with respect to the engine load fluctuation. There were drawbacks. On the other hand, the present invention overcomes such drawbacks and aims to realize higher speed and higher accuracy engine speed control. As described in detail below, the present invention reduces the speed deviation from the target engine speed. The engine speed limit control is performed by controlling the air flow rate by the electronic control throttle based on this.

  As shown in FIG. 1, the present embodiment has an engine speed (signal) 1, a target engine speed (signal) 2, a target throttle opening (signal) 3, a throttle opening (signal) 4, an electronic control throttle ( ETC) 5, engine 6, hold block 7, and accelerator pedal signal (APS) 8. The target throttle opening degree 3 is determined as follows.

尚、誤差信号は次の数式２による。

ここで、θ_dは目標スロットル開度、Ｎ_dは目標エンジン回転速度、Ｎはエンジン回転速度、eはエンジン回転速度の目標エンジン回転速度に対する誤差、ＡＰＳ_holはリミット制御起動条件成立時のアクセルペダル信号から求められた目標スロットル開度、Ｋ₁〜Ｋ₃は定数であり、条件不成立時は正常の制御に戻る。 When N> Nd, which is the starting condition for engine speed limit control, is satisfied, the target throttle opening 3 is obtained from the error signal between the target engine speed 2 and the engine speed 1 by the following formula 1.

The error signal is given by the following formula 2.

Here, θ _d is the target throttle opening, N _d is the target engine speed, N is the engine speed, e is the error of the engine speed with respect to the target engine speed, and APS _hol is the accelerator pedal when the limit control activation condition is satisfied. The target throttle opening degree K ₁ -K ₃ obtained from the signal is a constant, and returns to normal control when the condition is not satisfied.

  The present invention relates to the intake air for the engine rotation speed 1 to become the target (limit) engine rotation speed 2 in accordance with the intake air amount sucked into the engine 6 by the electronic control throttle 5 with respect to the engine rotation speed limit control system. This is a new engine speed control method to which the model base control for determining the amount, that is, the target throttle opening 3, is applied.

  The purpose of this limit control is to control the actual engine speed 1 so that it does not exceed the determined target engine speed 2 under all operating conditions. When the engine 6 is started, the engine speed 1 Then, the value of the target engine speed 2 is compared. If the actual engine speed 1 is larger than the target engine speed 2, the value of the accelerator pedal signal (APS) 8 that is the input at that time is held in the hold block 7. Is held (stored).

  Based on this value, the target throttle opening degree 3 is obtained by using the above formula 1 so that the engine rotational speed 1 becomes the target engine rotational speed 2, and further, the obtained target throttle opening degree 3 and the input accelerator. The value of the pedal signal (APS) 8 is compared, and the smaller one is set as the actual target throttle opening 3.

  Then, it is assumed that the electronic control throttle 5 is controlled so that the throttle opening 4 becomes the target throttle opening 3, and the engine speed 1 is set to the target in accordance with the intake air amount sucked into the engine 6 by the electronic control throttle 5. (Limit) The engine 6 is controlled so that the engine speed 2 is reached.

  Therefore, even when the load on the engine 6 fluctuates and the engine speed 1 suddenly increases, the actual engine speed 1 can be kept within the specified target (limit) engine speed 2 in the direction of high speed and high speed. It can be controlled with high accuracy.

  As described above, according to the present invention, the engine speed can be controlled so as not to exceed a predetermined speed limit even in a situation where the engine load fluctuates without causing an increase in cost.

1 engine speed, 2 target engine speed, 3 target throttle opening, 4 throttle opening, 5 electronic control throttle, 6 engine, 7 hold block, 8 accelerator pedal signal

Claims (4)

  The engine speed control device determines the target throttle opening based on the detected engine speed and outputs a drive signal to an actuator for opening and closing the throttle valve disposed in the intake passage of the engine. In an engine speed control method for executing limit control so that the engine speed does not exceed a predetermined speed limit while adjusting, when the engine speed exceeds the speed limit, the throttle opening at that time is set. An engine rotational speed control method, comprising: storing and determining the target throttle opening so that the engine rotational speed is within a speed limit using a predetermined mathematical formula based on the stored throttle opening. The formula is

(However, θ _d is the target throttle opening, N _d is the target engine speed, N is the engine speed, e is the error of the engine speed with respect to the target engine speed, and APS _hol is the accelerator pedal when the limit control activation condition is satisfied. target throttle opening degree obtained from the signal, K ₁ ~K ₃ is a constant), the engine rotational speed control method according to claim 1, characterized in that.   2. The target throttle opening determined by the mathematical formula is compared with the throttle opening by the input accelerator pedal signal, and the smaller one is output as the final target throttle opening. Or the engine speed control method described in 2. The throttle opening is connected to an engine speed detecting means and an actuator for opening / closing the throttle valve, and determines the target throttle opening based on the engine speed and outputs a drive signal to the opening / closing actuator. A control device that executes the limit control so that the engine speed does not exceed a predetermined speed limit while adjusting the engine speed, and implements the engine speed control method according to claim 1, 2, or 3 A control device comprising a control program.

Images