ES2257994T3 - PROCEDURE AND DEVICE FOR THE CONTROL OF AN INTERNAL COMBUSTION ENGINE. - Google Patents

Abstract

Procedure for the control of an internal combustion engine (100) with a regulation / control (140), which influences the number of revolutions (N) of the internal combustion engine (100), in which depending on at least one variable characteristic of the operation (N) of the internal combustion engine (100) a quantity variable can be predetermined, which determines the amount of fuel injected into the internal combustion engine (100), and in which, from a first variable (D), which characterizes the performance of the amount of fuel injected, can influence the behavior of the regulation / control (140), characterized in that the first variable (D) corresponds to the relationship between the modification of the variable of quantity and the modification, which is derived from it, of a second variable, which characterizes the moment of the internal combustion engine (100).

Description

Procedure and device for controlling a Internal combustion engine.

State of the art

The invention relates to a method and a device for controlling an internal combustion engine according to the preambles of the independent claims.

In the control of internal combustion engines, especially for diesel internal combustion engines, different speed regulations contribute to comfort of the March. Examples of such regulators of the number of revolutions are a regulator of idling, a shock absorber, a regulator of the stability of the gear and / or regulation of the flow compensation. The variable  The adjustment of all these regulators is the amount of injection. Especially in internal combustion injection engines Direct, in normal operation, the amount of injection is approximately proportional to the torque, which is available for The internal combustion engine. This affects in a way advantageous about the activity of the regulator.

A procedure and a device for speed regulation are known, for example, to from document DE 195 27 218. This regulation / control influences on the number of revolutions of the internal combustion engine, being predetermined, based on at least one value of the number of revolutions, a variable that determines the amount of fuel injected into the internal combustion engine.

For the reduction of emissions are used, especially in diesel internal combustion engines, concepts of post-treatment of exhaust gases. Such concepts of post-treatment of exhaust gases they contain, among others, the so-called accumulation catalysts of NOx as well as particle filters. Such treatment systems subsequent exhaust gases require interventions in the fuel injection In this case, the amount of injection, the beginning of the injection as well as the distribution of the amount of injection over a previous injection, an injection main and, if necessary, a subsequent injection depending on the control of the post-treatment system of gases escape. In addition, the system of post-treatment of gases from exhaust can influence the air supply to the engine of internal combustion in the sense of a reduction in the amount of air or in the sense of a decrease in the Lambda value of Exhaust gases

A post gas treatment system Exhaust is known, for example, from DE 195 47 646. There fuel is further dosed, contributing the additional fuel in the after-treatment system of exhaust gases to the reduction of azo oxides.

System control interventions post-treatment of exhaust gases may have an impact on a very strong way about regulating the number of revolutions, since in this case the basic precondition for the regulator it is that the amount is proportional to the torque, no or not already in the same way that is carried out in the state of usual operation of the internal combustion engine. A simple disconnection of speed regulators it can lead, on the one hand, to considerable damage to the comfort and, on the other hand, to an increase in emissions of exhaust gases.

Otherwise, it is known from document DE 40 28 809 (US 5,313,855) a system, in which several systems partials act on the dosage of the fuel. In this In this case, different priorities are associated with partial systems individual.

They are known from US 5,685,270 A a procedure and control of an internal combustion engine with a to regulation / control, which influence the number of internal combustion engine revolutions. Depending on one characteristic variable of combustion engine operation internal a quantity variable is predetermined, which determines the amount of fuel injected into the internal combustion engine.  The characteristic variable of the internal combustion engine is provided, for example, the actual engine speed of internal combustion, which is fed to a PID regulator. At least one PID regulator parameter is variable, and you can learn the value. Accordingly, the regulation / control can be influenced by a variable, which characterizes the actions of the amount of fuel injected. As variable is predetermined modification of engine speed internal combustion.

Advantages of the invention

Through the procedure according to the invention the damages of the ride comfort through system interventions post treatment of exhaust gases. The repercussions of the interventions of other systems on the injection of fuel and the speed regulation is They can clearly reduce. No knowledge of the intervention of the post-treatment system of gases exhaust or other systems on fuel dosing during the correction in the speed controller. Is that the causes of the damage in the speed regulator.

The advantages and configurations and Convenient developments of the invention are indicated in the dependent claims.

He drew

The invention is explained below with the help of the embodiments represented in the drawing. The Figure 1 shows a block diagram of the device according with the invention and figure 2 shows a block diagram of the procedure according to the invention.

Description of the embodiment example

The following describes how to proceed from according to the invention in the example of the control of a motor of Diesel internal combustion. But the way to proceed according to the invention is not limited to the application in combustion engines Diesel internal, but can also be used in other engines Internal combustion

The method of proceeding according to the invention is described in the example of a system for the subsequent treatment of exhaust gases. The exhaust gas after-treatment system intervenes in the control of the quantity and / or air in such a way that the relationship between the amount of fuel injected and the engine torque is no longer constant. But the procedure according to the invention is not limited to this application. It can also be used in other systems, which perform an intervention
correspondent.

Figure 1 shows how to proceed according to the invention with the help of a block diagram. An internal combustion engine is designated 100. In it is provided a speed sensor 105. To the engine of internal combustion 100 fuel is dosed through a quantity regulator 110. The fuel dosage is carried carried out based on a distribution of the quantity 115, which activates the quantity regulator 110. The distribution of the quantity 115 processes the output signal of a link point 120 at whose first input is the output signal of a point of link 125. In the first entry of link point 125, find the output signal of a device for determining the desire of driver 130, which is fed as input variable at least the output signal of a pedal indicator of the throttle 135. This throttle pedal indicator 135 It provides a signal, which characterizes the driver's desire. In instead of an accelerator pedal you can also use a E gas system or other means, which supply a signal, which Characterize the driver's desire.

In the second entry of link point 125, find the output signal of a regulator of the number of revolutions 140, which is driven by the output signal N of the speed sensor. In place and / or as a complement of the speed regulator can be provided also a regulator of gait stability, a regulation of the amount compensation. The concept of regulator of number of revolutions 140 must be understood in the sense that from a signal of the number of revolutions a fuel quantity as adjustment variable. In particular, the speed regulator 140 can be set as control

In the second entry of link point 120, find the output signal of a treatment device rear exhaust 150, which drives with signals additionally an air control 145 as well as the device quantity distribution 115. Air control 145 drives a air regulator 120, which influences the amount of air fed to the internal combustion engine. Instead of the device after treatment of exhaust gases 150 can be also use other systems, which influence the amount of fuel and / or over the amount of air.

The mode of operation of these elements is Know regularly. The default driver through the pedal of the throttle 135 a desire of the driver, which is converted by the driver desire determination device 130 in a amount of fuel The distribution device of the quantity 115 distributes this amount of fuel in at least a partial injection In normal operation, it is dosed the entire amount of fuel in a preferred manner by means of a partial injection device. In the newest systems it may be provided that for the minimization of noise, in certain operating states, the injection is distributed in a previous injection and a main injection.

The speed regulator 140 guarantees that the number of revolutions does not fall below a minimum speed For the rest, the number regulator of revolutions 140 contains different functions, such as a shock absorber, a regulator of the stability of the gear or a quantity compensation regulation. Usually, speed regulators 140 are designed in such a way that a certain adjustment variable, which corresponds to a certain amount of fuel, has as consequence a certain modification of the engine torque in the engine Internal combustion

The most recent systems are equipped with a after-treatment system for exhaust gases 150. Thus, for example, it may be provided that for the regeneration of a accumulation catalyst and / or a carbon black filter or another after-treatment system for exhaust gases, in a determined moment, under certain operating conditions, internal combustion engine control can be performed so that the lambda air index is less than 1. This means that in the cylinder is a rich mixture. This has of again as a consequence that part of the fuel has arrived not burned to the gas exhaust duct and reacted there in the Exhaust gas after-treatment system. For the In addition, it may be planned to dose from the device distribution of the quantity 115 a part of the quantity of fuel injected after dosing itself of fuel as a subsequent injection. Also this fuel Fill unburned to the exhaust pipe. These effects have as a consequence that the amount of fuel injected and The emitted motor torque is no longer proportional to each other.

To maintain its theoretical value, the regulator of number of revolutions 140 must inject a high amount of fuel. The exact forecast of the amount through the speed regulator is only possible when know the exact relationships of the post treatment system of exhaust gases and the mode of action.

To avoid this, it is planned in accordance with the invention that defines a variable, which is designated below as intervention In this case, it is about the relationship between the torque and injection quantity. The standardized intervention D is obtained through the division of the intervention by a value of the intervention, which is present in normal functioning. As normal operation, the operating state is designated usual diesel engine with excess air, that is, with a value Lambda greater than 1. Next, the intervention is designated normalized as an intervention of quantity D.

In normal operation, the intervention of the quantity is D = 1. In the rich operating mode, that is, with a Lambda value less than 1, the standardized intervention of the quantity D adopts values less than 1. In the extreme case, the value D becomes 0. This means that the regulator of the number of  revolutions no longer exerts any action on the torque. This corresponds to a separation of the number regulation circuit of revolutions. According to the invention, the regulator of the number of revolutions takes into account the intervention of the quantity D. In this case, consideration of the intervention of the quantity D is independent of the cause that causes the modification of the intervention of the quantity.

In normal operation, the intervention of the quantity D adopts the value 1. It is especially advantageous that also with values, which are insignificantly less than 1, it carry out normal operation. This means that in a first range of intervention values of the quantity, it It performs normal operation.

If the intervention of the quantity is D = 0, it is say, if the speed controller does not already have no torque intervention, then disconnects or else freezes the speed controller in one way adequate. It is especially advantageous for the regulator to be frozen. with integral behavior, as for example in the case of regulation of quantity compensation or regulation of the gait stability of the portion I of the regulator. Is especially advantageous that also with values, which are insignificantly greater than 0, measures can be taken corresponding. This means that in a second interval of intervention values of the quantity, the speed regulator 140.

If the quantity intervention is greater than 0 and less than or equal to 1, the speed regulator still has an intervention of moments on the amount of injection. This intervention may be weakened, however, versus normal operation. According to the invention, the regulator compensates for this reduced intervention from the amount to through the adaptation of the regulator parameters. By example, in the case of a PI regulator, the constants corresponding are high with respect to operation normal. This means that between the first range of values and the second range of values the relationship of the speed regulation 140 in such a way that compensates for the weakened performance of the amount of fuel injected

To this end it is planned that a determination of the intervention of the quantity 160 drive the number regulator of revolutions 140 with a corresponding D signal. The determination of the intervention of the quantity 160 receives signals from a Lambda 165 sensor and / or from the quantity distribution 115

According to the invention, the intervention of the quantity D is determined from the Lambda air index. TO for this purpose, a 165 sensor can be used especially. But also it is possible to determine the air index by calculation from the theoretical amount of injection and the amount of fresh air. By otherwise, the Lambda air index can be determined by a model from other input variables.

Another possibility to determine variable D it consists in predetermining the intervention of the quantity D, to from the distribution of the injection in previous injection, main injection and subsequent injection. In particular, it is placed zero quantity intervention when a subsequent injection If no subsequent injection is made, then it starts from a D = 1.

Otherwise, there is the possibility of determining D, when corresponding sensors are present, in a way direct from the amount of injection and engine torque.

The speed regulator 140 has consider the intervention of quantity D through the adaptation of the regulation parameters. To avoid, in the as much as possible, interventions through the device after treatment of exhaust gases 150, especially in critical situations for regulators of the number of revolutions, it is provided, according to the invention, that transmit a signal to the post-treatment device of the exhaust gases 150, which ensures that the quantity intervention. This can be done because the after-treatment device for exhaust gases 150 assume the intervention as quickly as possible or abandons a planned intervention.

To this end, a signal is expected to arrive from the throttle pedal position indicator 135 and signals arrive from other sensors 175 towards a forecast of priority 170. This forecast of priority 170 drives from new exhaust gas after-treatment device 150 with a corresponding priority signal.

Thus, for example, it can be provided especially that in a state of operation, in which the pedal value or the pedal value gradient adopts a very small value, a priority signal is transmitted corresponding, which allows an intervention of the quantity corresponding through the speed regulator. In this way, the idle speed regulator is achieved present sufficient adjustment reserves to maintain the engine of internal combustion in the minimum speed.

For the rest, it is planned to be contemplated a coupling switch, which guarantees the regulation of the number of revolutions of the internal combustion engine in the state disengaged.

Otherwise, it may be expected that transmit a signal, which indicates the position of the march. Of this mode it is possible that in certain gears, in which they appear several times shaking phenomena, the shock absorber of the Shakes receive, in addition, the intervention of the amount.

Otherwise, other variables are possible, which are conditioned by the electronic control of the gearbox or by the automatic gearbox, which characterizes a desired force drag on the drive section. This way is guaranteed that in certain operating states, the intervention of the quantity adopts the value 1 or a near value to 1.

This means that through the signal of priority of the forecast of priority 170 is achieved that the after-treatment device for exhaust gases 150 it recovers its intervention and thus the intervention of the quantity adopts the value 1.

Figure 2 shows how to proceed according to the invention. In a first stage 200 it is determined intervention of the normalized amount D. This can be perform, for example, because in a characteristic field deposits the relationship between a lambda value, which is detected by means of a Lambda sensor and the D value. Next, query 210 check if the intervention of the normalized quantity is D = 1. Yes this is not the case, then query 215 is carried out. In it is verified if the intervention of the quantity is D = 0. Yes this is the case, then in step 220 a counter is placed to zero. Next, corresponding measures are carried out. Thus, for example, portion I of the number regulator is frozen of revolutions. That is, the momentary value of the integrator.

If query 215 recognizes that the intervention of the quantity D is not equal to zero, then it is placed in the stage 225 marker M also zero. For the rest, they start in the stage 125 different measures to compensate for the intervention of the reduced quantity That is, especially the expansion of  the proportional portion.

It is especially advantageous that query 215 verify if the intervention of quantity D is less than a value threshold. In this way, it is guaranteed that in the case of very small intervention of quantity D, can be started corresponding measures as in the case of an intervention of the amount of D = 0. This is especially important when the value D is wrong or can only be determined very little exact.

If query 210 recognizes that the value is D = 1, then it is checked in step 230 if the marker is M = 0. The marker M = 0 indicates that in the previous development of the program They have initiated special measures. If this is not the case, then the program continues normal operation with step 240. If the value is set M = 0, then they are reset in step 235 the measures from the previous cycle of the program, that is, by example, portion I of the different ones is initialized again regulators, portions I are initialized in a preferred manner With the memorized values. This means that portion I has been frozen with a recognized value of D = 0 or less than a value threshold.

Claims (7)

1. Procedure for the control of an internal combustion engine (100) with a regulation / control (140), which influences the number of revolutions (N) of the internal combustion engine (100), in which depending on the minus a characteristic variable of the operation (N) of the internal combustion engine (100) a quantity variable can be predetermined, which determines the amount of fuel injected into the internal combustion engine (100), and in which, from a first variable (D), which characterizes the performance of the amount of fuel injected, can influence the behavior of the regulation / control (140), characterized in that the first variable (D) corresponds to the relationship between the modification of the quantity variable and the modification, which derives from it, from a second variable, which characterizes the moment of the internal combustion engine (100). 2. Method according to claim 1, characterized in that a normal operation is carried out in a second range of values of the first variable (D). 3. Method according to claim 1 or 2, characterized in that the regulation / control (140) is switched off in a second range of values of the first variable (D). Method according to one of the preceding claims, characterized in that the regulation / control is frozen (140). 5. Method according to one of the preceding claims, characterized in that between the first range of values and the second range of values the behavior of the regulation / control (140) is modified so that the weakened performance of the amount of fuel is compensated injected Method according to one of the preceding claims, characterized in that the first variable (D) is calculated from a Lambda value and / or an injection curve. 7. Device for the control of an internal combustion engine (100) with a regulation / control (140); that influences the number of revolutions (N) of the internal combustion engine (100), with means, which predetermine, depending on at least one characteristic variable of operation (N) of the internal combustion engine (100), a variable of quantity, which determines the amount of fuel injected into the internal combustion engine (100), with means, which starting from a first variable (D), which characterizes the performance of the amount of fuel injected, influence the behavior of the regulation / control (140), characterized in that the first variable (D) corresponds to the relationship between the modification of the quantity variable and the modification resulting from a second variable, which characterizes the moment of the internal combustion engine
(100)