DE10047821B4 - Method for Radmomentkonstanthaltung in a motor vehicle and corresponding idle control arrangement - Google Patents

Abstract

Method for maintaining wheel constants in a motor vehicle, wherein the operating behavior of a drive motor coupled to at least one drive wheel (4) of the motor vehicle is regulated by means of an idle controller (3) during idling, characterized in that the idling controller (3) during a ratio change of the transmission (2) is initialized such that due to the ratio change no additional idling control torque (MII) is caused.

Description

The present invention relates to a method for maintaining the wheel moment in a motor vehicle according to the preamble of claim 1 and to a corresponding idler control arrangement according to the preamble of claim 7.

It is known that in motor vehicles idle speed controller for controlling the engine speed in idle mode, ie in no-load operation used. For this purpose, for example, in idling mode, the instantaneous speed of the engine can be detected and compared with a target speed. If the current speed (actual speed) is smaller than the target speed, a control signal for increasing the motor torque is generated, while a control signal for reducing the motor torque is generated if the actual speed is greater than the target speed is. A corresponding idle controller is for example in the JP S63-94 079 A described. In a diesel engine, the amount of fuel supplied to the individual combustion chambers of the diesel engine is usually adjusted by means of the idle controller in order to regulate the engine speed or torque during idling operation in this way.

An adjustment of the engine torque at a change in the transmission ratio is from the DE 43 09 903 A1 known. In the document, when changing the gear ratio, the engine speed is controlled from a 1st value to a 2nd value, and a firing angle correction is made.

In the DE 195 08 889 A1 is first determined in dependence on a desired performance with a first stored map an associated Radmomentwert. Via a second stored map, a transmission gear is determined in order to achieve the Radmomentwert the most economical.

From the DE 34 00 951 A1 is a scheme for switching operations is known in which the throttle valve is controlled in the switching operation to prevent speed drops or speed overshoot. A similar method for control in overrun or idle is from the DE 37 44 222 A1 known.

Conventional idling controllers generally have a proportional component (P component) and an integrating component (I component). If the motor vehicle is currently in idling mode and the engine speed is increased beyond the setpoint speed actually intended for idling operation during idling operation by depression of the accelerator pedal, the different effects of the P component and the I component in this specific operating case will cause the I. Share against the driver's request. To prevent this effect, the I-part of the idle controller is frozen in this particular operating case, d. H. disabled, so that the I component remains constant at its old value. This has the consequence that in this special case always only the speed proportional shares (P-shares) are effective.

In particular, in so-called AMS systems ("aggregate management systems"), ie systems in which the wheel torque is to be kept constant, by calculating the gear ratio transmitted to the drive wheels wheel torque at a constant accelerator pedal, ie at the same driver's request, before and after one Circuit kept constant. Since a ratio change associated with a circuit leads to an engine speed change, this can result in the lower speed range, that the idle controller an additional idle control torque is caused, which provides an additional contribution to the driver's request. In this case, the wheel torque is not constant. This will be explained in more detail below with reference to 3 be explained.

In 3 In general, a switching process is shown when a translation U _{old is switched} to a _new translation U. The course of the translation is in 3 denoted by U. As long as the shift has not yet been initiated and the translation U = U _old , the idle controller is compensated. It is now assumed that the driver with constantly depressed accelerator pedal, ie at the same driver's request, the in 3 shown circuit or ratio change from U _old to U _new performs, ie during the circuit, the accelerator pedal is constantly depressed by the driver. With the in 3 shown switching process is connected to a reduction of the engine speed N _mot . Due to the reduced engine speed N _{mot of} the idle controller is active, wherein the P portion of the idle controller according to 3 increasing moment M _p generated. Since the I component of the idle controller M _{i is} constant, the increase of the P component results in a corresponding increase in the total idle controller torque M _II . The resulting increase in the idling controller total torque M _II causes a corresponding increase in the transmitted to the drive wheels of the motor vehicle wheel torque M _rad , as in 3 is shown above. The wheel torque is thus increased by the amount M _rad = M _II × U _new and accelerates the vehicle accordingly, although the accelerator pedal is constantly depressed by the driver during the shift, ie the wheel torque M _rad is not constant despite the constant driver's request.

The present invention is therefore based on the object to propose a method for Radmomentkonstanthaltung in a motor vehicle and a corresponding idle controller arrangement, whereby the wheel torque can be kept constant even during a shift, ie during a ratio change, with constant driver's request.

This object is achieved by a method having the features of claim 1 and an idler control arrangement with the features of claim 7. The subclaims each define preferred and advantageous embodiments of the present invention.

According to the invention it is proposed that the idle controller during a ratio change, d. H. during a shift, to initialize such that no change in the wheel torque actually transmitted to the drive wheels is caused by an idle control torque caused by the idle controller. In the case of an idle controller with an I component, this can be done in particular by initializing the I component during the ratio change accordingly.

For this purpose, at the beginning of a gear change, the moment supplied by the I-part may be "frozen", i. H. are detected and the I-part of the idle controller depending on the value thus detected, the old translation, the new translation and the P-part of the idle controller are initialized accordingly. With continuous translation changes, initialization, i. H. Adjustment of the I component, to be carried out continuously during the switching process or during each sampling step.

The present invention is particularly suitable for motor vehicles with AMS ("Aggregate Management Systems") for keeping constant the wheel torque during a switching operation, as by the initialization of the I-part of the idle controller, the wheel torque can be kept constant even if during the switching operation, the accelerator pedal is constantly depressed by the driver.

The present invention will be explained in more detail below with reference to the accompanying drawings with reference to a preferred embodiment.

1 shows a simplified block diagram of an open-loop regulator arrangement according to a preferred embodiment of the present invention,

2 shows a diagram for explaining the operation of the present invention during a switching operation, and

3 shows a diagram for explaining the associated with a switching operation problems according to the prior art.

In 1 is an internal combustion engine 1 , For example, a diesel engine, shown, which via a transmission input shaft with an automatic transmission 2 a motor vehicle is coupled. From the transmission 2 becomes a driving torque on wheels 4 of the motor vehicle.

Furthermore, in 1 an idle controller 3 which has a P-component and an I-component C in the example described below. The idle controller 3 contains control means 5 which is continuously one of the transmission 2 supplied control signal, the instantaneous translation of the transmission 2 corresponds, evaluate. In this way, the control means 5 determine when a switching operation and consequently a ratio change is performed. In addition, the tax credits 5 always the instantaneous transmission ratio 2 known. The control means 5 are designed such that they by evaluating the of the transmission 2 provided control signal on the one hand detect the beginning of a translation change and on the other hand, the I-share 6 of the idle controller 3 initialize during the ratio change such that due to a ratio change no changed wheel torque, ie no increase or reduction of the drive wheels 4 transmitted wheel torque is caused.

This will be explained in more detail below in accordance with 2 illustrated exemplary representation of a switching operation are explained, wherein according to the in 3 shown representation is assumed that with the aid of a switching operation, the ratio U of the transmission 2 is switched from a translation U _old to a translation U _new . The instantaneous value of the transmission ratio 2 is always defined by the quotient U = wheel torque / clutch torque.

How out 2 is apparent, is with the switching operation whose duration in 2 is denoted by T, a corresponding reduction of the engine speed N _mot connected (see also 3 ). Unlike the in 3 shown procedure in which the I-share M _i is constant over the entire switching process, is in accordance with 2 proposed, during the ratio change to initialize the I-part of the idle controller such that adjust, depending on the value of the P-portion of the idle controller, no increase in the drive wheels 4 transmitted wheel torque M _{rad is} caused. Ideally, the I component of the idle controller is initialized such that the I component M _{i of} the idle controller torque compensates for the P component M _{p of} the idle controller torque.

For this purpose, at the beginning of the change in the conversion, the I component of the idle-control torque is "frozen", ie held in the form of the value M ₀ . The I-part M _{i of} the idle-control torque is now initialized as a function of the values U _old , U _new , M ₀ and M _p as follows: M _i = (U _old / U _new ) × M ₀ - M _p

Since the in 1 shown control means 5 always the instantaneous value of the gear ratio 2 It can be known in a continuous translation change, as in 2 is shown, according to the I-share M _i according to the above formula continuously adjusted when the new value of the translation U _new always the instantaneous value of the translation U is used during the shift or during the ratio change. In this case, the results in 2 shown course of the I component M _{i of} the idle controller torque.

How out 2 can be seen, is ensured in this way that during or as a result of a switching operation or a ratio change, no increase of the idle controller 3 generated idle controller total torque M _{II is} caused. Accordingly - as well as out 2 it can be seen - that on the drive wheels 4 transmitted wheel torque M _{rad be} kept constant regardless of the switching operation.

Overall, it is thus ensured that a constant wheel torque M _{rad is} generated even during a gear ratio change while the accelerator pedal is depressed, which thus corresponds to the driver's request.

LIST OF REFERENCE NUMBERS

1

internal combustion engine

2

transmission

3

Idle controller

4

drive wheel

5

control means

8th

I-part of the idle controller

U

translation

U _old

old translation value

U _new

new translation value

M _rad

wheel torque

M _II

Idle regulator total moment

M _i

I-part of the idling torque

M _p

P component of the idling torque

N _mot

Engine speed

M _o

Value of the I component of the idling torque at the beginning of a gear change

T

Duration of the translation change

Claims (9)

Method for keeping the wheel moment constant in a motor vehicle, with the aid of an idling controller ( 3 ) the operating behavior of a via a transmission ( 2 ) with at least one drive wheel ( 4 ) of the motor vehicle coupled drive motor is controlled at idle, characterized in that the idle controller ( 3 ) during a ratio change of the transmission ( 2 ) is initialized such that due to the ratio change no additional idling control torque (M _II ) is caused. Method according to claim 1, wherein the idle controller ( 3 ) has an I component (6) and a P component, characterized in that the I component (6) of the idle controller ( 3 ) during the ratio change of the transmission ( 2 ) is initialized such that due to the ratio change no additional idling control torque (M _II ) is caused. A method according to claim 2, characterized in that the I-part (6) of the idle controller ( 3 ) during the ratio change of the transmission ( 2 ) is initialized such that an I-portion M _i of the idle controller ( 3 ) and a P-part M _p of the idle controller ( 3 ) compensated for idling control torque generated. Method according to Claim 2 or 3, characterized in that, at the beginning of the ratio change, the instantaneous value of the I component M ₀ of the idling controller ( 3 ) and then the I-part M _{i of} the idle-control torque in dependence on the P Is initialized proportion M _{p of} the idling torque according to the following relationship: M _i = (U _old / U _new ) × M ₀ - M _p , where U _{old is} the gear ratio ( 2 ) at the beginning of the ratio change and U _new the transmission ratio ( 2 ) after the translation change. Method according to Claim 2 or 3, characterized in that, at the beginning of the ratio change, the instantaneous value of the I component M ₀ of the idling controller ( 3 ) and then the I-part M _{i of} the idle-control torque is initialized in dependence on the P-part M _{p of} the idle-control torque according to the following relationship: M _i = (U _old / U _new ) × M ₀ - M _p , where U _{old is} the gear ratio ( 2 ) at the beginning of the ratio change and U _new the instantaneous value of the transmission ratio ( 2 ) designated. Method according to claim 5, characterized in that of the transmission ( 2 ) continuously the instantaneous value of the ratio (U) of the transmission ( 2 ) is made available. Idle control arrangement for a motor vehicle, with an idle controller ( 3 ) for controlling the operating behavior of a via a transmission ( 2 ) with at least one drive wheel ( 4 ) of the motor vehicle coupled to the engine idling, characterized in that control means ( 5 ) for initializing the idle controller ( 3 ) during a ratio change of the transmission ( 2 ) are provided such that due to the ratio change of the transmission ( 2 ) no additional from the idle controller ( 3 ) produced idle control torque (M _II ) is caused. Idling controller arrangement according to claim 7, characterized in that the idle controller ( 3 ) or the control means ( 5 ) are configured for carrying out the method according to one of claims 1-6. Idler controller arrangement according to claim 7 or 8, characterized in that the control means ( 5 ) in the idle controller ( 3 ) are integrated.

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