JP2001073848A - Controlling method and device for rotating speed of drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce the overshoot of revolving speed in the starting process of an internal-combustion engine. SOLUTION: A controlling method and device for the revolving speed of a drive unit include a control means which adjusts the ignition angle of an internal-combustion engine as a function of deviation of the actual revolving speed from its target value. The control device has at least one variable parameter, which takes a value at starting different from the value during the normal control operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a rotational speed of a drive unit.

[0002]

2. Description of the Related Art Such a method or such a device is known, for example, from EP-A-33 616. There, an idle speed control device is proposed, which, as a function of the deviation of the measured engine speed from a predetermined target value, so as to bring the speed close to a predetermined target speed. The amount of air supply to the internal combustion engine is adjusted via the first engagement path, and the ignition angle of the internal combustion engine is adjusted via the second engagement path. In such an idle rotation speed control device, a relatively large rotation speed overshoot exceeding the target steady-state rotation speed occurs within the range of the starting process regardless of the engagement path to the ignition angle. Control comfort and riding comfort may be adversely affected.

[0003]

It is an object of the present invention to provide a method and an apparatus for effectively reducing such overshoot of an internal combustion engine.

[0004]

According to the above-mentioned object, a deviation of a rotation speed of a drive unit from a predetermined rotation speed is formed,
As a function of this deviation, at least 1
In a method for controlling the rotational speed of a drive unit, an operating signal for adjusting the rotational speed is generated using two variable parameters, during a starting process of the internal combustion engine, the value of the at least one parameter of the control device is increased. This is achieved by a method for controlling the rotational speed of a drive unit according to the invention, characterized in that it is varied.

[0005] The above object also comprises a control device for generating a manipulated variable for adjusting the rotational speed as a function of the deviation of the rotational speed of the internal combustion engine from a predetermined target rotational speed, said control device comprising at least one variable parameter. A control device for controlling the rotational speed of the drive unit, wherein the control device is provided with switching means, and the switching means sets at least one parameter when starting the drive unit to another value different from the normal control operation. This is achieved by the control device for controlling the rotational speed of the drive unit according to the present invention, characterized in that:

[0006] The setting of at least one parameter which is particularly adapted for the rotational speed control device for effecting the ignition angle engagement at start-up effectively reduces the rotational speed overshoot in this process. In this case, the starting process is a process of engine operation in which the rotation speed is controlled by operating a starting device or by turning on ignition (supply voltage) until the rotation speed reaches a range of a target steady-state value (which changes in an operating state). Is understood. In a preferred embodiment, the starting process is terminated when the rotational speed first falls below the predetermined rotational speed value again after overshooting above the steady rotational speed.

[0007] It is particularly advantageous during the start-up process that at least one parameter is selected to dynamically and effectively reduce the rotational speed overshoot. Therefore, a parameter that leads to instability in the control circuit may be selected in a steady operation other than the starting process.

It is particularly advantageous that the selection of the parameters is adapted to the form of the rotational speed overshoot, so that an optimal adjustment of the rotational speed overshoot is made.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. FIG. 1 shows a flow chart of the idle speed control device, which adjusts not only the supply amount to the internal combustion engine but also the ignition angle of the internal combustion engine so that the actual rotation speed approaches the target rotation speed. In a preferred embodiment, the flowchart shows a microprocessor program, which is part of a control unit for controlling the internal combustion engine. The control unit or the microprocessor is designated in FIG. Control unit 10 or microprocessor 10
In the meantime, signals representing operating variables are supplied by a corresponding measuring device, which is not shown in FIG.
A signal value representing the engine speed NIST is supplied via the first input line. Via other input variables, the engine temperature TMOT, the state S of auxiliary consumers, such as air conditioners,
Signals for other operating variables of the engine or vehicle, such as T, vehicle speed VFZ, etc., are provided. In addition, the microcomputer or control unit 10 outputs a signal ZUE relating to the activation of the ignition switch (where "UE" stands for U umlaut in German) (alternatively, the activation of the starting device or the activation signal of the supply voltage). receive. When the control unit is switched on, a target idle speed NSOLLL is determined in a target value forming stage 12 as a function of a supply operating variable such as, for example, the engine temperature and / or the state of the auxiliary device. This is performed on the basis of a characteristic curve, a group of characteristic curves, a table or a calculation step, respectively, depending on the embodiment. In a preferred embodiment, the target value forming stage 12 is formed as a program of the microcomputer 10. Then, in a comparison stage 14 (also formed as a program step), a deviation Δ between the thus formed target idle speed NSOLL and the received actual speed NIST is formed.
Next, the control deviation Δ is supplied to the idling control device 16 shown by a broken line.

In a preferred embodiment, the idling controller 16 consists essentially of a conventional PID controller (a controller having a proportional, a derivative and an integral part), where the P and D parts are , Are provided in duplicate. In the illustrated embodiment, PI
The D control acts on the charge (air supply) and the PD control (only the proportional and derivative parts) acts on the ignition angle. In a preferred embodiment, the derivative for the ignition angle path operates only at rotational speeds well below idle speed. Thus, in this embodiment, the proportional part to the ignition angle path is used for the effect of the idling control device on the ignition angle. In a preferred embodiment, the output signal of the proportional part is formed from the product of the rotational speed deviation Δ and the characteristic curve. This characteristic curve is a function of the rotational speed deviation, in which case the parameters (proportional coefficients) of the characteristic curve are chosen such that the engine rotational speed is stable. In this case, this coefficient may be varied as a function of the value of the control deviation. This coefficient indicates the slope of the characteristic curve. In another embodiment, the D portion operates within the entire rotational speed range. Furthermore, in other embodiments, other control types are used, in which case at least one variable parameter that affects the dynamics of the control device is always provided.

In the flow chart of FIG. 1, the control deviation is determined for the air supply path by an integral part 18, a proportional and differential part 2
0 and for the ignition angle path to a differentiating part 22 and a proportional part 24, respectively. Within the individual control components, the control deviation is evaluated accordingly, integrated in the integrator 18, differentiated in the derivative part, and amplified, for example, in the proportional part as described above. in this case,
The output signals of the control components are collected for the charging path and the ignition angle path, respectively. Therefore, the integrator 18
And the output signal of the proportional / differential section 20 are combined (eg, summed) in a combining stage 26 and output to an electrically operated throttle valve 28, for example, as an output signal for air charge control. Similarly, in a combining stage 30, the output signal of the derivative portion 22 and the output signal of the proportional portion 24 for the ignition angle path are combined (eg, summed) and the combined signal is output via an output line for adjustment of the ignition angle. Output.

Further, a threshold stage 32 is provided, to which a signal representing the engine speed NIST is supplied. If the engine speed NIST is too low, this threshold stage 32 outputs a signal which activates the differentiating part 22 of the ignition angle control. If the engine speed NIST exceeds the threshold value checked in the threshold stage 32, the derivative part is deactivated again.

For the proportional part 24 of the ignition angle control, two different values or characteristic curves are stored in the memory cells 34 and 36 for the normal operation and the start-up process. In addition, a switching element 38 (formed as a program step) is provided, the switching element 38 being activated during the start-up process of the internal combustion engine. l
By lrst, the normal position shown by the solid line is switched to the starting position shown by the broken line. This signal is generated in the signal forming stage 40 (formed as a program step) on the basis of the control deviation Δ or, in another embodiment, the target rotational speed NSOLL and the actual rotational speed NIST and a signal ZUE (indicating the start of the starting process). It is formed on the basis of ignition on, supply voltage supply or operation of a starter.

When the internal combustion engine is started, it is assumed that the engine rotation speed increases and first exceeds the target rotation speed NSOLL. Thereafter, a rotational speed overshoot occurs, and this overshoot disappears after a predetermined time.
If the engine speed initially drops below the threshold value, in a preferred embodiment the starting process is deemed to have ended and the signal B set by turning on the supply voltage or by operating the starting device. llrst is reset. This means that if the rotational speed threshold is exceeded, the parameter P for normal operation is based on the ignition angle adjustment instead of the parameter PST for the starting process. During the rotational speed overshoot, the idle rotational speed control device is activated, so that the idle rotational speed control device acts in the opposite direction to the rotational speed overshoot. Therefore, the parameters for the starting process are designed to optimally reduce the rotational speed overshoot. That is, within reference numeral 40, after the supply voltage is applied, the actual rotational speed and the target rotational speed are compared with each other, and when the actual rotational speed decreases from the higher rotational speed, a predetermined threshold (for example, NSOLLL +
ΔN). If the actual rotational speed falls below this predetermined threshold, the signal B llrst is reset, so that the parameter P for normal operation is loaded instead of the parameter PST, and the parameter P is selected in terms of comfortable and stable control. Instead of the threshold value, the end of the starting process and the resetting of the signal are guided when the rotational speed is being controlled to an essentially steady rotational speed.

[0015] With a particular choice of proportional amplification of the ignition angle control, it is possible to achieve a larger circuit amplification of the control and thus to effectively suppress overshoot. Since the normal amplification is switched again after the start overshoot disappears, there is no possibility that the control circuit becomes unstable. In this case, the signal B for the entire operation cycle llrst is reset. This signal is set again with the next start-up process. The rotational speed threshold is determined by the application for each use case and may be greater than, less than or equal to the steady-state target rotational speed.

FIG. 2 shows the operation of the method in a time diagram. In this case, FIG.
The time lapse of mot (actual rotation speed NIST), the time lapse of the ignition angle ZW in FIG. 2B, and the time lapse of the ignition angle ZW in FIG.
Control signal B The time course of llrst is graduated.

In FIG. 2A, a typical progress of the engine speed at the time of starting the internal combustion engine is shown by a solid line. At time t0, the starting device is operated and the internal combustion engine is started. Since the fuel supply amount is increased at the time of starting, the engine rotation speed is increased beyond the steady target rotation speed nStat. This causes an overshoot, which is reduced by the corresponding engagement of the idle speed control device, and finally causes the speed to converge to the steady-state target idle speed at time t4. The progression of the ignition angle is shown in FIG. The normal course of the ignition angle in the idle speed control device is shown by a solid line, and the ignition angle is designed based on the running operation. The ignition angle is the basic ignition angle ZWBA
It is possible to change between S and the minimum ignition angle ZWMIN. At the basic ignition angle, a large torque is generated, and at the minimum ignition angle, a small torque is generated. The progress of the ignition angle indicated by the solid line shows the situation in which normal amplification for steady-state idling control is also used in the starting process. The course is selected so that the idling is as stable as possible. Since the ignition angle change is hardly dynamic, it does not utilize the full potential of torque reduction. Therefore, the overshoot (see the solid line) shown in FIG. 2A increases correspondingly.

As described above, at time t0, the signal B is output from the starting device of the internal combustion engine. llrst is set.
This provides optimum amplification for the starting process.
Correspondingly, the ignition angle curve ZW 'shown by the broken line is shown in FIG.
(B), the ignition angle curve ZW '
In, the ignition angle is reduced to the minimum ignition angle. As a result, as shown by a broken line in FIG. 2A, the rotational speed overshoot nmot 'is essentially reduced. Time t
1, when the engine rotation speed falls below a predetermined rotation speed threshold value (here, the threshold value is nStat + ΔN), as shown in FIG. llrst is reset and the ignition angle control is given an amplification for normal operation. As a result, the rotation speed overshoot at the time of starting is reduced, and quick control of the rotation speed to the steady target rotation speed is obtained.

In the preferred embodiment, the switching does not occur abruptly, but is smoothed by a filter function. In another embodiment, instead of or in addition to the above-mentioned effect on the proportional amplification factor of the ignition angle control device, the derivative of this control device and / or the charging control device (18 The corresponding coefficient of −22) is changed. In this case, only one coefficient of the control device, or any combination of selected coefficients, or all coefficients may be changed.

[0020] Depending on the embodiment, at least one
One variable parameter has only one value or a plurality of values (for example, in the form of a characteristic curve) during the start-up process, corresponding to the method for normal control operation.

[Brief description of the drawings]

FIG. 1 is a flowchart of an idling control device having air engagement and ignition angle engagement.

FIGS. 2A and 2B are time diagrams showing the effect of parameter switching in the starting process, wherein FIG. 2A shows the time lapse of the engine speed nmot, FIG. 2B shows the time lapse of the ignition angle ZW, and FIG. B The time elapse of llrst is shown.

DESCRIPTION OF SYMBOLS 10 Control unit (microprocessor) 12 Target value forming stage 14 Comparison stage 16 Idling control device 18 Integral part 20 Proportional and integral part 22 Differential part 24 Proportional part 26, 30 Coupling stage 28 Electrically operated throttle valve 32 Threshold stage 34, 36 memory cell 38 switching means (switching element) 40 signal forming stage

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 41/06 310 F02D 41/06 310 41/08 310 41/08 310 43/00 301 43/00 301B 301K F02P 5/15 F02P 5/15 E (72) Inventor Mario Kustsch 71706 Markgrey Ningen, Aof Hart 75/1

Claims (11)

[Claims] 1. A deviation of the rotational speed of the drive unit from a predetermined rotational speed is formed, and as a function of this deviation, the rotational speed is determined by the control device (16) using at least one variable parameter (P). A method for controlling the rotational speed of a drive unit, in which an operating signal for adjusting is generated, wherein the value of this at least one parameter (P) of the control device (16) is changed during the starting process of the internal combustion engine. A method for controlling the rotational speed of a drive unit, characterized in that: 2. The method according to claim 1, wherein a first value of at least one parameter for the starting process is set after the start and until the first rotational speed overshoot ends, and thereafter the operation is switched to a normal operation. The described method. 3. The method according to claim 1, wherein the end of the rotational speed overshoot is detected when the rotational speed falls below a predetermined rotational speed threshold value. 4. The method according to claim 1, wherein the at least one parameter is a proportional amplification factor. 5. The method according to claim 1, wherein at least one parameter is designed to achieve a maximum ignition angle change having a maximum possible dynamic characteristic in order to reduce the rotational speed overshoot during the starting process. The method according to any one of claims 1 to 4. 6. The method according to claim 1, wherein the control device has a derivative part and a proportional part. 7. The method according to claim 6, wherein the differentiating part is effective only at low rotational speeds. 8. The method according to claim 1, wherein the operating signal of the control device adjusts the ignition angle of the internal combustion engine. 9. A further control device is provided as a function of the rotational speed deviation, said other control device preferably having a proportional part, a differential part and an integral part, and a manipulated variable of said other control device. 9. A method as claimed in any one of the preceding claims, wherein a engages the air supply of the internal combustion engine. 10. A switching signal is generated at the start of the starting process, preferably at the time of ignition, wherein said switching signal operates parameter switching of said control device, and said switching signal is reset at the end of said starting process. 10. The method according to claim 1, wherein this operates a switch to a parameter for normal operation. 11. A control unit (16) for generating a manipulated variable for adjusting the rotational speed as a function of the deviation of the rotational speed of the internal combustion engine from a predetermined target rotational speed, said control unit comprising at least one variable parameter. (P) The control device for the rotation speed of the drive unit, wherein the control device (16) is provided with switching means (38),
The control device for controlling the rotation speed of the drive unit, wherein the switching means (38) switches at least one parameter to another value different from the normal control operation when the drive unit is started.