JPH06241103A - Engine controlling method - Google Patents

Abstract

PURPOSE:To improve following performance and stability of engine control by calculating acceleration up to a target value from rotating speed of an engine and the operating pattern of the target value of torque, and automatically converting control of the engine at the stabilized part and the transient part of the operating pattern. CONSTITUTION:The operating pattern of the target value (101) of rotating speed of an engine is outputted, and the deviation of the target value (101) from a command value (106) is found out. This deviation value is inputted into a control means 102 for carrying out integral control and a control means 103 for carrying out proportional control. Acceleration up to the target value is detected 104 from the stabilized part and the transient part of the operation pattern of the target value, and a converting device 105 is switched and controlled in complanc with the magnitude of the acceleration on the basis of its detected result. Namely, when control of the engine is carried out to the transient part, control of the engine is switched into proportional control for placing emphasis on good following performance. And when control of the engine is carried out to the stabilized part, control of the engine is switched into integral control for placing emphasis on stability so as to control engine while setting the output signal of a selected control means 102 or 103 as a command value 106.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control method for outputting a control value from an operation pattern of a target value of engine speed or torque.

[0002]

2. Description of the Related Art Conventionally, in this type of control method, as shown in FIG. 4, a target value is output in step 201, feedback control is subsequently performed (step 202), and a control value is output (step 203). I was doing. For example, in FIG. 2 showing the operation pattern of the engine speed-time characteristic, the operation pattern is changed from the stationary portion S of the stationary straight line A to the transient portion T of the transient straight line B that changes linearly and then again to the stationary straight line C. The target value is set so as to reach the section S.

[0003]

However, in the above-mentioned conventional control method, the whole area of the steady part S and the transient part T is set to the step 2
As shown in 02, since only one control is covered, a follow-up delay as shown by a thin line in FIG. The displacement curve b deviates greatly, or the steady portion S following the transitional portion T has a large overshoot and exhibits an unstable curve f lacking in stability. With this, it is difficult to operate the engine accurately with respect to the target value.

The present invention has been made in view of the above problems, and an object thereof is to obtain an engine control method capable of accurately operating an engine with respect to target values of engine speed and torque.

[0005]

According to the present invention, a known (proportional + integral) control operation in which proportional control is combined with integral control is used as automatic switching means for performing control of the engine. In order to overcome the limitation of operating accuracy of the engine due to having to cover both the stationary part and the transient part with one control method, the present inventors have detected acceleration and determined its magnitude. We focused on the fact that the control operation can be switched by. From this point of view, the present inventors first introduce an operation pattern for easily detecting the acceleration with respect to the target value of the engine speed or torque, and then, based on the acceleration detected from the target value. In order to solve the above problems in the steady part and the transient part, a control method that emphasizes stability is selected in the steady part according to its size, while in the transient part, control that emphasizes followability is selected. We have decided that it is preferable to switch the control so as to select the method.

Thus, according to the present invention, the acceleration with respect to the target value is calculated from the operation pattern of the target value of the engine speed or torque, and based on the calculation result, the control of the engine is performed by the steady part and the transient part of the operation pattern. The present invention provides an engine control method including automatic switching by.

That is, according to the present invention, by calculating the acceleration of the target value, the control of the engine is automatically switched by selecting the control method corresponding to each of the steady part and the transient part of the operation pattern, and thereby the steady state is achieved. It is possible to stabilize the unstable part and to alleviate the delay in tracking in the transient part.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an engine control method according to the present invention will be described below with reference to the drawings. In FIG. 1, in the engine control method, first, in step 101, an operation pattern of a target value of the engine speed is output, and subsequently feedback control (integral control) is performed (see step 102), and different feedback control is performed. (Proportional control)
Is also performed (see step 103). On the other hand, the acceleration with respect to the target value is calculated from the steady portion S and the transitional portion T of the operation pattern of the target value shown in FIG. 2 (see step 104), and the magnitude of the acceleration based on the calculation result (see FIG. 3)
When the control for the engine is performed on the transient portion T, the feedback control (proportional control) that emphasizes followability is switched, and when the control on the steady portion S is performed, the feedback control that emphasizes stability is performed. The mode is switched to (integral control) (see step 105). At this time, the magnitudes P and Q (P> Q) of the acceleration are as shown in FIG.
Is generally larger (size P) than that of the stationary part S (size Q). Further, the above switching can be performed, for example, by referring to the Y value (Y = constant) as the magnitude of acceleration in FIG. Further, an automatic switching device having a function of appropriately and automatically switching control (proportional / integral) to the engine based on the magnitudes P and Q of the acceleration is provided. Finally, in step 106, each command value is output as a control value.

As a result, curves d and g shown by dotted lines in FIG. 2 were obtained. That is, in the rising part of the transitional part T,
The displacement curve b has a shape in which the tracking delay is relaxed as compared with the displacement curve b which is largely deviated from the transient line B, and the steady portion S following the transient portion T has a large overshoot and lacks stability. It can be seen that a stable stable curve g having a smaller overshoot than the stable curve f is exhibited.

As described above, in this embodiment, the magnitude of the acceleration with respect to the target value is obtained from the operation pattern of the target value of the engine speed and the torque, and the proportional P and Q are used to switch to a known control method. Since the / integral switching control is used, a follow-up delay may occur at the rising portion of the transient portion T,
In the steady portion S following the transitional portion T, it is possible to prevent the overshoot from becoming large and lack of stability, and the engine can be operated accurately with respect to the target value.

[0011]

As described above, according to the present invention, by calculating the acceleration of the target value, the control of the engine is automatically switched by selecting the control method corresponding to each of the steady part and the transient part of the operation pattern. This makes it possible to stabilize the steady part that was unstable, and alleviate the tracking delay that occurred in the transient part.As a result, the trackability and stability of the engine speed and torque to the target values can be reduced. And the operating accuracy of the engine is improved.

[Brief description of drawings]

FIG. 1 is a flow chart configuration explanatory view showing an embodiment of the present invention.

FIG. 2 is an engine speed-time characteristic diagram showing an operation pattern of a target value of the engine speed and a control result.

FIG. 3 is a characteristic diagram showing acceleration of a target value in the above embodiment.

FIG. 4 is a flowchart showing a conventional example.

[Explanation of symbols]

A, C ... Steady straight line of target value operation pattern, B ... Transient straight line of target value operation pattern, S ... Steady part in target value operation pattern, T ... Transient part in target value operation pattern, P, Q ... The magnitude of acceleration.

Claims (2)

[Claims] 1. An acceleration for a target value is calculated from an operation pattern of a target value of engine speed and torque, and control of the engine is automatically switched between a steady part and a transient part of the operation pattern based on the calculation result. Engine control method consisting of things. 2. The automatic switching is performed such that integral control is performed in a steady part and proportional control is performed in a transient part.
The engine control method described in.