DE10253004A1 - Electronic drive control system for road vehicle internal combustion engine has overrun resistance monitor and internal resistance monitor producing control correction signals - Google Patents

Abstract

A control block (10) handles driver control inputs. It includes a vehicle speed regulator (11), an engine control map (12) and an overrun adjustment module (13). Outputs from the map and the overrun adjustment are added (14). A maximum value circuit (15) is connected to a moment coordination module (20) whose output is divided by a control input signal (U). The result may pass to a gear control circuit (22). The output (FWU) passes to subtractors (45,46) producing a value for the inner moment of the engine (IM). Further circuits produce a desired value signal (SM).

Description

State of technology

The invention is based on one Method for operating an internal combustion engine, in particular one Motor vehicle in which a frictional torque is generated, which in the Operation represents existing internal friction of the internal combustion engine, where an idle torque is generated by an idle controller, and in which the friction torque and the idling torque are linked and used to control and / or regulate the internal combustion engine become. The invention also relates to a corresponding control device for an internal combustion engine and a corresponding internal combustion engine.

It is known to be an idle controller to use with a first controller concept, which is essentially consists of a pilot control. In this case, the idle controller delivers in the adjusted state, a manipulated variable that is zero. alternative it is known to have an idle controller with a second controller concept to be used which generates a manipulated variable in the regulated state, that is not zero.

For the two different idle controllers it is necessary the rest Control and / or regulation of the internal combustion engine also in each case train different ones. It is not possible with that alternatively, both idle controllers described in a uniform, common parent Include regulation.

The object of the invention is a Method for operating an internal combustion engine, in particular one To create a motor vehicle in which the two controller concepts described for the Idle controllers can alternatively be used.

This task is done in a process of the type mentioned in the invention solved in that the friction torque is linked to a correction variable, which is based on the controller concept of the idle controller is.

According to the invention, a correction quantity is therefore introduced, the for the two described controller concepts is different. At a alternative use of the controller concepts, it is only necessary the correction variable depending on to change the controller concept used in each case. A is such a change very simple and therefore inexpensive feasible. The two controller concepts for the idle controller so without much effort alternatively used at will.

In an advantageous embodiment The invention uses the friction losses as a correction variable weighting factor representing the internal combustion engine if the idle controller is based on a controller concept, which essentially consists of a pilot control. By the weighting factor can therefore use the first controller concept in a simple manner come.

It is particularly advantageous if the ratio of the target speed as the weighting factor to the actual speed of the internal combustion engine is used.

Another advantageous Embodiment of the invention, the correction quantity is set to "one", if the idle controller is based on a controller concept in which generated by the idle controller in the regulated state, a manipulated variable that is non-zero. So the second can easily Controller concept can be applied.

With an advantageous further education The invention creates an accessory moment that for the Operation of additional devices to be generated by the internal combustion engine Represents moment and that the additional moment with the Correction variable is linked. On this way the different controller concepts also with regard to if necessary existing additional equipment of the internal combustion engine is taken into account become.

embodiments the invention

Other features, possible applications and advantages of the invention will become apparent from the following description of embodiments of the invention, which are shown in the drawing. Make it up all described or illustrated features on their own or in any combination the subject of the invention, regardless of its summary in the claims or their relationship back as well as regardless of their formulation or presentation in the description or in the drawing.

The only figure in the drawing shows is a schematic block diagram of an embodiment of a method according to the invention for operating an internal combustion engine, in particular for a motor vehicle.

An internal combustion engine, for example of a motor vehicle, is known to be provided with an electronic control device which is suitable for providing the operating variables required for the operation of the internal combustion engine. These operating variables are, for example, the start of injection and the duration of injection, from and during which the fuel of the internal combustion engine by means of an injection valve di injected directly or fed through an intake pipe. The ignition point in time at which the injected fuel is ignited by means of a spark plug represents another example of an operating variable of the internal combustion engine.

These operating variables are used by the control unit for all operating states of the Internal combustion engine generated, i.e. for the partial or full load of the internal combustion engine or for the pushing operation or the idling operation of the internal combustion engine. In the operating states mentioned are the company sizes of Internal combustion engine controlled or regulated. This is for idle operation known to provide an idle controller. Especially in idle mode is achieved with the help of the control or regulation that the speed of the internal combustion engine has a desired idling speed.

To carry out such controls and Regulations is the control unit provided with a computer and a memory. Are in the store Computer programs stored that run on the computer and thus the desired functions To run can. About appropriate electrical Circuits are then e.g. the injectors from the control unit with the determined operating variables controlled.

With regard to the idle controller at least two different controller concepts are known.

It is possible that the idle controller consists essentially only of a pilot control. In this case are the friction losses of the internal combustion engine in advance as a function the speed and possibly the engine temperature. This friction loss are used by the idle controller as a weighting factor of a higher-level Scheme fed. The idle controller, for example a PI controller, works on the Basis of torque changes and just corrects the weighting factor. With the engine idling The weighting factor causes the speed of the internal combustion engine focus on the desired Idle speed. Because of the pilot control described is the manipulated variable of the idle controller zero when idling.

As an alternative, it is possible to Idle controller in the parent Integrate regulation. In this case, the idle controller works with absolute moment values. The friction losses of the internal combustion engine are from the idle controller, for example, with falling speed corrected with the help of a DT1 element. With the engine idling is the manipulated variable of the idle controller therefore not equal to zero.

In the figure is a method for Operating an internal combustion engine of a motor vehicle, in which the two controller concepts explained above for the idle controller can alternatively be integrated. The method shown in the figure and explained below can be used in internal combustion engines with direct injection or with intake manifold injection, as with Petrol or diesel engines are used.

A block 10 the figure is provided for determining a driver's request. The block 10 contains a vehicle speed control ll, a map 12 and a so-called overrun adjustment 13 ,

With the cruise control 11 A driver of the motor vehicle can preselect a desired driving speed, which is then automatically maintained by the method shown. The cruise control generates the output signal 11 a target torque that is required to reach the preselected driving speed based on the current speed.

The map 12 is acted upon by the instantaneous speed v of the motor vehicle and the accelerator pedal position FP of an accelerator pedal which can be operated by the driver. The map generates depending on this 12 a setpoint torque that is required in order to reach the driving speed based on the current speed that is desired by the driver via the accelerator pedal position.

The overrun adjustment 13 is acted upon by the accelerator pedal position FP, a loss quantity VG and a first correction quantity KR1. The function of overrun adjustment 13 will be explained below. The overrun adjustment 13 generates a correction moment from an addition 14 to that of the map 12 generated target torque is added.

That from the cruise control 11 generated target torque and that from the addition 14 Sum torque generated are fed to a maximum value selection 15, of which the larger of the two mentioned moments is passed on as the desired propulsion torque. This propulsion torque represents the torque that is required to control the vehicle speed 11 or to implement the accelerator pedal FP from the driver's request specified by the driver.

There is moment coordination in the figure 20 provided, which is acted upon by the desired propulsion torque. The moment coordination 20 can contain, among other things, a so-called electronic control program (ESP), which acts on the torque to be generated by the internal combustion engine. Generally the moment coordination 20 intended to automatically correct the desired propulsion torque. If, for example, the drive wheels of the motor vehicle "spin", this can be done by torque coordination 20 can be prevented by reducing the driving torque.

The corrected driving torque is calculated with the help of a division 21 to a transmission ratio Ü of the transmission present in the motor vehicle fit. The corrected and translated propulsion torque acts on a transmission intervention 22 , with which the aforementioned propulsion torque is adapted to the different gear stages of the transmission, among other things. The transmission intervention 22 generates a driver's desired torque FWM, which ultimately represents an engine input torque for the internal combustion engine.

In the figure is a block 30 shown, which is to represent additional devices of the motor vehicle. This can be a generator, an air conditioning system and the like. Such additional devices are driven at least indirectly by the internal combustion engine and must therefore be taken into account with regard to the torque to be generated by the internal combustion engine. For this purpose the block creates 30 an additional device torque ZEM, which in turn ultimately represents an engine input torque for the internal combustion engine.

In the figure is a broken line 35 shown. Left of this line 35 the functions explained so far are available. These refer to the motor vehicle. To the right of the line 35 there are functions which are explained below and which relate to the internal combustion engine. The driver's desired torque FWM and the additional device torque ZEM, which have also already been explained, represent requirements of the driver and the motor vehicle for the internal combustion engine.

The internal friction present during the operation of the internal combustion engine is shown in the figure by a block 40 represents. This block 40 generates a frictional torque RM, which represents the moment that must be applied by the internal combustion engine in order to overcome the internal friction.

The additional device moment ZEM and the friction moment RM are from an addition 41 summarized and a multiplication 42 fed. From multiplication 42 the already mentioned transmission ratio U of the transmission in the motor vehicle is taken into account. The multiplication generates the loss quantity VG already mentioned, that of the overrun adjustment 13 is fed.

According to the figure, the additional device torque ZEM and the friction torque RM are each a multiplication 43 . 44 fed. There they are multiplied by a second correction variable KR2. The corrected accessory torque and the corrected friction torque each become a subtraction 45 . 46 supplied, with the help of which the two aforementioned moments are subtracted from the driver's desired torque FWM. As a result, the internal moment IM of the internal combustion engine is created.

The idle controller mentioned at the beginning is in the figure by the block 50 represents. As will be explained below, the two explained controller concepts for the idle controller can alternatively be used.

The block 50 generates an idle torque LLM using an addition 51 is added to the internal moment IM of the internal combustion engine. In this way, a setpoint torque SM arises, which is passed on as an input signal for the above-mentioned higher-level control.

Will in the block 50 If the first-described controller concept is used, in which the idle controller essentially consists of a pilot control, the following applies: KR2 = 1 + KR1. In general, the first correction variable KR1 can be the weighting factor already mentioned in connection with the feedforward control. For example, the following can apply here: KR1 = nset / nact, with nset = setpoint speed of the internal combustion engine and nact = actual speed of the internal combustion engine.

In particular, by forming the second correction variable KR2 as the sum of the first correction variable KR1 plus one, it is taken into account that the idle controller of the block 50 is designed as a pilot control. The second correction variable KR2 has a value not equal to one, which has the consequence that the intervention of the second correction variable KR2 over the two multiplications 43 . 44 has an influence on the generated inner moment IM. The one in the block 50 Idle speed controller implemented in this case, as already mentioned, essentially does not make any contribution to the target torque SM in the adjusted state. Ultimately, this is done using the two multiplications 43 . 44 ,

Will in the block 50 uses the second controller concept described, the following applies: KR2 = 1 and KR1 = LLM / RM + ZEM. As a result, the two multiplications 43 . 44 have no influence on the generated inner moment IM. The one in the block 50 Idling controller implemented in this case can thus make its own contribution to the target torque SM via the idling torque LLM.

As has been explained, the first correction variable KR1 acts on the overrun adjustment 13 on. This overrun adjustment 13 It is provided that negative moments at the output of the transmission of the motor vehicle can also be taken into account with the described method. The Gverrun adaptation 13 is thus geared towards the transition from a pulling operation into a pushing operation of the internal combustion engine and vice versa.

As can be seen from the indicated characteristic curve in the figure, the overrun adjustment 13 the accelerator pedal position FP is not linearly converted into the correction torque mentioned at the outset, but is flattened. This flattening depends on the overrun adjustment 13 supplied loss variable VG and the first correction variable KR1.

The described method can, as described, be used with an idle controller, which essentially consists of a pilot control stands, and which therefore provides essentially no manipulated variable in the regulated state. In this first case, the two correction variables KR1, KR2 must be set accordingly. The procedure can also be used with an idle controller, which supplies its own control variable in the adjusted state. In this second case, KR2 = 1 applies and the first correction variable KR1 must be set accordingly.

The method described can thus be done without further explained with both at the beginning Regulator concepts of the idle controller are used.

Claims (11)

Method for operating an internal combustion engine, in particular of a motor vehicle, in which a frictional torque (RM) is generated which represents the internal friction of the internal combustion engine during operation, in which an idling torque (LLM) is generated by an idling controller, and in which the frictional torque ( RM) and the idle torque (LLM) are linked to one another and used to control and / or regulate the internal combustion engine, characterized in that the friction torque (RM) is linked to a correction variable (KR2) which is dependent on the controller concept of the idle controller. A method according to claim 1, characterized in that as a correction variable (KR2) a weighting factor representing the frictional losses of the internal combustion engine is used when the idle controller is based on a controller concept lies, which consists essentially of a pilot control. A method according to claim 2, characterized in that as a weighting factor the ratio of the target speed (nsoll) to the actual speed (nist) of the internal combustion engine becomes. A method according to claim 1, characterized in that the correction quantity (KR1) is set to "one" when the idle controller is based on a controller concept in which generates a manipulated variable to the idle controller in the regulated state that is non-zero. Method according to one of the preceding claims, characterized characterized that the friction torque (RM) from a driver's desired torque (FWM) is subtracted, the driver's desired torque (FWM) being an input torque for the internal combustion engine and that the idle torque (LLM) results in the Subtraction added becomes. Method according to one of the preceding claims, characterized characterized that an additional device moment (ZEM) generates is that for the operation of additional equipment from the internal combustion engine generating moment and that the accessory moment (ZEM) with the correction variable (KR2) connected becomes. A method according to claim 6, characterized in that the auxiliary device torque (ZEM) is from a driver request torque (FWM) is deducted, the driver's desired torque (FWM) being an input torque for the Internal combustion engine represents, and that the idle torque (LLM) too is added to the result of the subtraction. Computer program with program instructions that are suitable for this are to carry out the method according to any one of claims 1 to 7 if they run on a computer become. Memory, in particular flash memory, on which a computer program is stored, which has program instructions suitable for this are to carry out the method according to any one of claims 1 to 7 if they run on a computer become. control unit for one Internal combustion engine, in particular of a motor vehicle, of which one Frictional torque (RM) is generated, which is the existing internal one during operation Friction of the internal combustion engine represents an idling torque (LLM) is generated by an idle controller, and from which the friction torque (RM) and the idle torque (LLM) are linked and used to control and / or regulate the internal combustion engine are characterized in that the friction torque (RM) of the control unit with a correction variable (KR2) connected which is dependent on the controller concept of the idle controller. Internal combustion engine, in particular for a motor vehicle, with a control unit, from which a frictional torque (RM) is generated which corresponds to the existing represents internal friction of the internal combustion engine, of which an idling torque (LLM) is generated by an idle regulator, and from which the friction torque (RM) and the idle torque (LLM) are linked and used to control and / or regulate the internal combustion engine are characterized in that the friction torque (RM) of the control unit with a correction variable (KR2) connected which is dependent on the controller concept of the idle controller.