EP0227536A1 - Feedback control apparatus for an internal-combustion engine, and method using such an apparatus - Google Patents

Abstract

This combustion engine regulation device (1), the operation of which is governed by a set of parameters P _i (1 ≦ i ≦ n), essentially comprises a set of "m regulation loops (2 _1. 3 _1. 3 ₂ . 3 _3. 4 _1. 6 ₁ ) allowing to regulate 'm' parameters (with m ≦ n). A set of "q" sensors (3 _4. 3 _s ) (with q = nm) allowing to measure the parameters possibly not regulated and a regulator (5. 8) common to all of these "m" loops allowing, from the different setpoints and the values read by the different sensors, to develop a control signal for the different actuators so to ensure the evolution of each of the regulated parameters, in conjunction with the evolution of all or part of the other parameters, regulable or not, regulated or not, and thus to maintain the engine in optimum condition at all times.

Application to motor regulation.

Description

The present invention relates to the regulation of combustion engines.

A combustion engine, for example petrol or diesel. can be considered a complex system whose operation is governed by a certain number of parameters. such as air flow. diesel flow. air temperature. air pressure. motor speed. power ... etc.

Current regulation devices are generally designed to provide either a single regulation function, such as speed regulation, or flow regulation, or richness regulation, etc., or several regulation functions, but in a completely independent manner.

These devices have the drawback of changing each of the parameters completely independently of the others. However, these different parameters interact with each other, all the more closely since the engine is complex and defined by a large number of parameters.

The subject of the present invention is a regulation device making it possible to carry out different types of regulation taking into account the interactions between the different parameters, and thus to maintain the engine at all times in an optimal operating state, hence in particular an optimal efficiency. and an improved lifespan.

• - un ensemble de "m" boucles de régulation. permettant de réguler "m" paramètres (avec m≦n). comportant chacune notamment un ou plusieurs organes d'entrée de consigne, un ou plusieurs actionneurs pour agir sur le moteur de façon à modifier la valeur du ou des paramètres correspondants, et un ou plusieurs capteurs pour mesurer la valeur du ou des paramètres ainsi modifiés :
• - un ensemble de "q" capteurs (avec q = n-m) permettant de mesurer des paramètres éventuellement non régulables ;
• - un régulateur commun à l'ensemble de ces "m" boucles, permettant, à partir des différentes consignes et des valeurs relevées par les différents capteurs, d'élaborer un signal de commande des différents actionneurs de façon à assurer l'évolution de chacun des paramètres régulés, en liaison avec l'évolution de tout ou partie des autres paramètres. régulables ou non, régulés ou non.

According to the invention, a combustion engine regulation device, the operation of which is governed by a set of parameters Pi (1 ≦ i ≦ n). is essentially characterized in that it comprises:

• - a set of "m" regulation loops. allowing to regulate "m" parameters (with m ≦ n). each comprising in particular one or more setpoint input members, one or more actuators for acting on the motor so as to modify the value of the corresponding parameter or parameters, and one or more sensors for measuring the value of the parameter or parameters thus modified:
• - a set of "q" sensors (with q = nm) making it possible to measure possibly non-controllable parameters;
• - a regulator common to all of these "m" loops, making it possible, from the different setpoints and values recorded by the different sensors, to develop a control signal from the different actuators so as to ensure the evolution of each regulated parameters, in connection with the evolution of all or part of the other parameters. regulable or not, regulated or not.

• - la figure 1 est un schéma d un dispositif de régulation suivant l'invention
• - les figures 2a. 2b. 2c. 2d et 2e sont des exemples de courbes relatifs à différents types de régulation pouvant être mis en oeuvre par le dispositif de régulation suivant l'invention :
• - la figure 3 est un exemple d'organigramme général de fonctionnement du dispositif suivant l'invention :
• - la figure 4 montre plus en détail un exemple de réalisation de la phase de régulation proprement dite. intervenant dans l'organigramme de la figure 3.

Other objects and characteristics of the present invention will appear more clearly on reading the following description of an exemplary embodiment. made in connection with the attached drawings in which:

• - Figure 1 is a diagram of a regulating device according to the invention
• - Figures 2a. 2b. 2c. 2d and 2e are examples of curves relating to different types of regulation that can be implemented by the regulation device according to the invention:
• FIG. 3 is an example of a general flowchart of operation of the device according to the invention:
• - Figure 4 shows in more detail an embodiment of the actual regulation phase. involved in the flowchart of figure 3.

According to the example described in FIG. 1, the regulation of a motor 1 is carried out by means of three regulation loops allowing one to achieve a power regulation, another a speed regulation and another a richness regulation.

• - un organe de commande, permettant à l'opérateur de fixer la valeur de la consigne, respectivement de puissance : 2₁, de vitesse : 2₂ et de richesse 2₃ ;
• - un capteur, respectivement de puissance : 3i, de vitesse : 3₂, et de richesse : 3₃ ;
• - un organe de comparaison de la consigne et de la grandeur correspondante mesurée par le capteur, respectivement 4₁, 4₂ et 4₃ ;
• - un actionneur, respectivement de puissance : 6₁, de vitesse : 6₂ et de richesse 6₃, agissant sur les paramètres correspondants du moteur.

Each of these loops comprises in known manner:

• - a control member, allowing the operator to set the setpoint value, respectively of power: 2 ₁ , of speed: 2 ₂ and of richness 2 ₃ ;
• - a sensor, respectively of power: 3i, of speed: 3 ₂ , and of richness: 3 ₃ ;
• a member for comparing the setpoint and the corresponding quantity measured by the sensor, respectively 4 ₁ , 4 ₂ and 4 ₃ ;
• - an actuator, respectively of power: 6 ₁ , of speed: 6 ₂ and of richness 6 ₃ , acting on the corresponding parameters of the motor.

The device according to the invention also comprises a regulator 5 which is common to all of the regulation loops and which makes it possible to carry out different types of regulation taking into account the interactions between the different parameters.

This regulator 5 receives the output signals from the various comparison bodies 4 _i , 4 ₂ , 4 ₃ , as well as the signals from sensors 3 ₄ and 3 ₅ for example making it possible to ensure the acquisition of certain parameters which cannot be regulated by this device, such as temperature and pressure, and delivers the input signals of the various actuators.

There are also provided, between the three comparators 4 ,, 4 ₂ and 4 ₃ , and the regulator 5, a set of three other comparators. respectively 7 ₁ , 7 ₂ , 7 ₃ . allowing the parameters relating to each of the control loops, namely power, speed and richness, to be compared with three extreme values called respectively power stop, speed stop and richness stop, so as to ensure the operation of the motor below of these extreme values.

A module 10 carries out the acquisitions of the different setpoints or commands, their processing and filtering to make them usable by the comparators and the regulator. The respective setpoint weighting operations are also carried out, and this according to the parameters recorded by the man-machine interface 9.

The assembly formed by this module 10 by the various comparators and by the regulator is in fact constituted by a computer 8 which is programmed in a manner which will be described later. in relation to FIGS. 3 and 4, to carry out different types of regulation such as those described now. for exemple. in relation to Figures 2a to 2e. the selection between these different types of regulation being carried out by the operator by means of a man-machine interface 9 which communicates with the computer 8.

The device according to the invention allows, for example, the realization of speed regulation. of wealth. of power, either independently. either in combination, simultaneously or separately.

• - réalisation d'une régulation de vitesse : le régulateur génère une loi de commande de l'actionneur de vitesse en fonction de la consigne de vitesse. telle que celle représentée à titre d'exemple sur la figure 2a, de façon à assurer une évolution ou un maintien de la vitesse du moteur en liaison avec l'évolution ou le maintien de la consigne de vitesse (par exemple accélérateur), les autres paramètres pouvant amener des corrections.

In the context of carrying out independent regulations, three cases are possible:

• - implementation of speed regulation: the regulator generates a speed actuator control law according to the speed setpoint. such as that shown by way of example in FIG. 2a, so as to ensure an evolution or a maintenance of the speed of the motor in connection with the evolution or the maintenance of the speed reference (for example accelerator), the others parameters that can lead to corrections.

de la consigne de vitesse C_v et des autres paramètres Pi :

avec i variable de 1 à n, où n est le nombre de paramètres régissant le fonctionnement du moteur : - réalisation d'une régulation de puissance : le régulateur génère une loi de commande de l'actionneur de puissance en fonction de la consigne de puissance, telle que celle représentée à titre d'exemple sur la figure 2b. Les autres paramètres peuvent amener des corrections. ce qui conduit à une expression de la position de l'actionneur puissance "PAP" sous la forme d'une certaine fonction

de la consigne de puissance C_P et des autres paramètres P_i :

- réalisation d'une régulation de richesse : le régulateur génère une loi de commande de l'actionneur de richesse en fonction de la consigne de richesse, telle que celle représentée à titre d'exemple sur la figure 2c. Les autres paramètres peuvent amener des corrections, ce qui conduit à une expression de la position de l'actionneur richesse "PAR" sous la forme d'une fonction de la consigne de puissance Cp et des autres paramètres P_i :

The position of the speed actuator "PAV", can thus be written in the form of a certain function

the speed setpoint C _v and the other parameters Pi:

with i variable from 1 to n, where n is the number of parameters governing the operation of the motor: - carrying out power regulation: the regulator generates a power actuator control law as a function of the power setpoint , such as that shown by way of example in FIG. 2b. The other parameters can lead to corrections. which leads to an expression of the position of the power actuator "PAP" in the form of a certain function

of the power setpoint C _P and of the other parameters P _i :

- Realization of wealth regulation: the regulator generates a law for controlling the wealth actuator as a function of the wealth instruction, such as that shown by way of example in FIG. 2c. The other parameters can lead to corrections, which leads to an expression of the position of the wealth actuator "PAR" in the form of a function of the power setpoint Cp and of the other parameters P _i :

de la consigne de vitesse Cv et autres paramètres

et si cette consigne est inférieure à la valeur de seuil Cvs, le régulateur assure par exemple une régulation de type vitesse, pouvant s'exprimer sous la forme d'une certaine fonction

de la consigne de vitesse Cv et des autres paramètres

peuvent être des fonctions différentes des fonctions

définies précédemment.In the case of combined but separate regulations, for example speed regulation and wealth regulation as in Figure 2c. the regulator implements a single type of regulation at a given instant, but this type of regulation can change over time, as a function of a criterion which is the value of the setpoint. For example, if the setpoint (for example the speed setpoint) is less than a threshold value Cvs, the regulator provides richness type regulation for example, which can be expressed in the form of a certain function

of the speed reference Cv and other parameters

and if this setpoint is less than the threshold value Cvs, the regulator provides for example speed-type regulation, which can be expressed in the form of a certain function

the speed reference Cv and other parameters

may be functions different from functions

defined above.

In the case of combined and simultaneous regulations (case of Figure 2e), the regulator implements several types of regulation at a given time (for example speed, power and richness), each of which can be expressed in the form of a certain function of the corresponding setpoint and all or part of all of the other parameters, adjustable or not, regulated or not:

désignent des fonctions qui peuvent être différentes des fonctions

définies précédemment, sont calculées simultanément, ce qui permet de générer des lois optimales de commande des différents actionneurs.So the different expressions:

designate functions which may be different from functions

defined above, are calculated simultaneously, which makes it possible to generate optimal control laws for the different actuators.

The general flowchart of operation of the regulator is now described in relation to FIG. 3. This flowchart begins with the introduction of data by the operator: in particular the type of regulation desired (namely independent, or combined regulations, and for the case of combined regulations, separately or simultaneously, as defined above), and associated setpoint values. The regulator then proceeds to acquire tion of the various parameters of the system, via the various sensors. The regulator then checks the validity of the data entered by the operator. in order to verify that they are indeed compatible with the current state of the various parameters of the system and do not in particular entail operation in a critical zone.

The computer 8 also makes it possible to systematically store the various parameters governing the operation of the engine. and a control of their evolution over time thus ensuring a predictive diagnosis of failures.

In the event that these data are not compatible with the current state of the system, the operator is notified thereof by means of the man-machine interface 9. Otherwise. the information received from the sensors is compared to the different setpoints and stops, then the actual regulation is carried out, the operator being kept informed of the values of the different parameters and of the operating state of the system by means of the human interface - machine 9.

The actual regulation phase is described in the form of a flowchart in FIG. 4. For simplicity, this flowchart corresponds to the specific examples of regulation described in relation to FIGS. 2a to 2e. Depending on the type of regulation chosen (independent regulations. Combined separately or combined simultaneously), such or such formulas defined above in relation to FIGS. 2a to 2e are applied. with the corresponding values of the setpoints and parameters.

The different functions "f" defined above are predetermined as a function of each type of regulation and of the characteristics of the engine.

Furthermore, the different types of regulation described have been given only by way of examples. There are of course other possibilities. in particular the possibility of providing for each type of regulation different functions "f" according to the parameters Pi selected by the operator. or the possibility of carrying out intermediate types of regulation to those described (for example independent regulations on certain parameters, combined regulations on other parameters ... etc).

According to the embodiment which has been described, each regulation loop relating to a given parameter comprises a setpoint input member, a comparator, an actuator and a sensor, all relating to the parameter considered. More generally. there can be an interaction between the different parameters, not only with regard to the elaboration of the law of regulation of each of the parameters, as we saw previously, but also with regard to the very constitution of each of the regulation loops. in the sense that each of them can comprise several setpoint input members. several comparators. several actuators and several comparators. related to different parameters. which allows to change a given parameter. according to the desired regulatory law. by action on different parameters. and measurement and comparison of different parameters with corresponding set values.

The device according to the invention thus makes it possible to establish according to optimal control laws. monovariable or multivariable input-output type regulations. related to the parameters governing engine operation.

Claims (4)

1. A combustion engine regulation device (1), the operation of which is governed by a set of parameters P _I (1 ≦ i ≦ n), characterized in that it comprises: - a set of "m" regulation loops, making it possible to regulate "m" parameters (with m ≦ n), and each comprising in particular one or more setpoint input organs (2 ₁ ), one or more actuators (6d) to act on the engine so as to modify the value of the corresponding parameter or parameters, and one or more sensors (3 ₁ , 3 _2. 3 ₃ ) to measure the value of the parameter or parameters thus modified; - a set of "q" sensors (3 ₄ , 3s) (with q = nm) making it possible to measure parameters which may not be controllable; - a regulator (5, 8) common to all of these "m" loops, making it possible, on the basis of the different setpoints and the values recorded by the different sensors, to develop a control signal for the different actuators so as to ensure the evolution of each of the regulated parameters, in connection with the revolution of all or part of the other parameters, regulable or not, regulated or not. 2. Method for using the device according to claim 1. characterized in that the regulator (5, 8) makes it possible to regulate several parameters simultaneously, depending, for each of these parameters, on the corresponding setpoints and on any or part of the other parameters, regulable or not, regulated or not. 3. Method of using the device according to claim 1, characterized in that the regulator (5, 8) makes it possible to carry out the regulation of a single parameter at all times, but this can vary over time depending of the value of a determined setpoint. 4. Method of using the device according to claim 1, characterized in that the regulator (5, 8) makes it possible to carry out the regulation of a single parameter at all times, as a function of the value of the corresponding setpoint and of all or part of the other parameters. adjustable or not.

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