KR20040012514A - Method for controlling and/or regulating internal combustion engine - Google Patents

Abstract

PURPOSE: A control and/or regulation method for an internal combustion engine is provided to supply a torque set value that secures a favorable consumption of fuel. CONSTITUTION: A control and/or regulation method for an internal combustion engine comprises an intake tract having a throttle valve and a breather in a pipe parallel to the throttle valve and an accelerator pedal mechanically combining with the throttle valve and having an accelerator with a sensor for detecting positions for a pedal and the throttle valve. The control/regulation method is composed of steps for computing a value(40) for torque as a function of an accelerator pedal position(36); outputting a minimum value(44) of the torque for a reference value of the ignition angle and injection amount at a present pedal position and a breather-closed state; and comparing the computed value with the minimum value of the torque and transmitting the value larger than a torque set value(68) in two values to drive the internal combustion engine.

Description

METHOD FOR CONTROLLING AND / OR REGULATING INTERNAL COMBUSTION ENGINE}

The present invention relates to a method for controlling and / or adjusting an internal combustion engine having a throttle valve and an intake tract having a breather in a tube parallel to the throttle valve. The internal combustion engine also has an accelerator that is mechanically coupled to the throttle valve and a sensor for detecting the pedal position and the throttle valve position.

Internal combustion engines are known which have an intake side on which a throttle valve is installed and a bypass that runs parallel to the throttle valve. A breather is provided in the bypass. In this case, the set value of the crankshaft torque is calculated as a function of the accelerator position and corrected based on the control function of the internal combustion engine.

DE 198 03 664 A1 discloses a control method for calculating torque setpoints that can be used even in the case of an internal combustion engine with a throttle valve mechanically coupled to an accelerator. However, in the known method, for example, due to component tolerances, the torque setting in the calculation of the accelerator position and the preset throttle valve position is so low that the adjustment of the ignition angle must be delayed compared to the optimum state when the bypass breather is fully closed. This can happen. As a result, fuel consumption is increased and even the exhaust gas critical temperature can be reached.

In addition, a situation may occur in which the torque setting value is selected too high when the accelerator position is preset.

Apparatuses and methods are known for controlling an internal combustion engine from DE 100 65 516 A1. Here, the set value of the load variable is calculated based on the adjustable maximum load variable value and the variable representing the driver's intention. As a result, the value of the set torque and the amount of air are calculated based on the accelerator position.

It is an object of the present invention to provide a method for controlling and / or adjusting an internal combustion engine that provides a torque setpoint that can be realized with as advantageous fuel consumption as possible.

1 schematically shows an internal combustion engine with an engine control device.

2 is a block diagram illustrating a process for calculating a torque set value.

3 is a curve of intake air and torque, expressed as a function of accelerator pedal position.

* Description of the major symbols in the drawings *

10: internal combustion engine 20: suction tract

22: Throttle Valve 23: Accelerator Pedal

24: parallel tube 26: breather

32: sensor 36: accelerator pedal position

50: flow cross section 58: characteristic map

This object is achieved through a method comprising the features of claims 1 and / or 4 or 5 according to the invention. The dependent claims describe preferred embodiments of the method according to the invention.

The method according to the invention relates to a control method and / or an adjustment method of an internal combustion engine having a throttle valve and an intake tract having a breather in a tube parallel to the throttle valve. The internal combustion engine further includes an accelerator pedal mechanically coupled to the throttle valve, which includes an accelerator including a sensor for detecting the pedal position and the throttle valve position. The value of the torque is calculated based on the pedal position in a manner known per se. In the next step, the minimum value of torque is calculated when the breather is closed and at the current pedal position. When the breather in the parallel tube is closed, the air flow in the cylinder is only preset by the current pedal position or the throttle valve position associated with it. If the optimum ignition angle is maintained and the fuel injection amount does not change, then the minimum torque value that can be reached at a given pedal position becomes the prescribed minimum value, and a preset value may be added to the minimum value. In the final step, the calculated and minimum values for torque are compared with each other. The larger of the two values is then transferred as a setpoint for driving the internal combustion engine, and in some cases corrected by a control function. Using the method according to the invention it is ensured that the torque setpoint for driving the internal combustion engine is not transmitted without the intervention of a specific control function, which makes the adjustment of the ignition angle or the like necessary. . In the method according to the invention the torque setpoint is not smaller than the minimum value calculated for the torque at the breather closing and at the current pedal position.

Preferably, in order to limit the setpoint for the drive of the internal combustion engine, the minimum value for the torque is used only after the pedal position exceeds a preset minimum pedal position. In this way, the lower limit of the torque setpoint in the idle state is not limited.

The object according to the invention is also achieved through the method according to the preamble of claim 4, in which the value of torque is first calculated as a function of the accelerator position. The maximum value of torque is calculated for the fully open breather and the current pedal position. In a subsequent comparison step, the value passed as the setpoint for the drive of the internal combustion engine is limited to the calculated minimum value or slightly larger than the minimum value. Using the method according to the invention, the maximum torque achievable is calculated in a similar manner as in the calculation of the minimum torque.

The object according to the invention is also achieved through the method according to the preamble of claim 5, in which the relative demand torque is first calculated as a function of the accelerator position. The maximum value of torque is calculated for the case where the breather is fully open and for the current pedal position. The reference upper limit value for the relative demand torque is then set to a value corresponding to the maximum value or the maximum value increased by a predetermined value. The difference from the method according to claim 3 is that the relative demand torque is calculated, not the absolute value for the demand torque. The relative demand torque indicates which relative value of the torque interval should be used as the torque setting value. In this case, the maximum value is defined with respect to the upper limit of the torque range.

The advantage of the method according to the invention in the embodiments according to claims 1, 4 and 5 is that the effect on the driving force is greater than when the driver's intention is adjusted globally using a correction factor, for example in DE 198 09 664 A1. More dominant. In the method according to the invention using data that can be used in engine control, the minimum air volume and / or maximum air volume, i.e. the air amount at the closing of the breather and / or the air opening at the breather opening, is determined for the current pedal position. From the air volume the associated torque provided at the optimum ignition angle is calculated. In this way, adjustment of the ignition angle or a torque setpoint that is not feasible is avoided.

In one preferred embodiment, the minimum and / or maximum value for the torque is determined based on the value when the flow cross section in the throttle valve is reduced. The amount of air generated in the internal combustion engine depends on the reduced flow cross section at the throttle valve and the breather. Preferably the value for the reduced flow cross section is corrected for the situation.

In the following the method according to the invention is described in more detail with reference to the examples.

1 schematically shows an internal combustion engine 10 having a cylinder 12. For better understanding, only one cylinder of the internal combustion engine is shown in FIG. 1. The cylinder 12 is assigned a piston 14 including a connecting rod 16. The connecting rod 16 is connected to the piston 14 and the crankshaft 18.

The internal combustion engine has a suction tract 20 including a throttle valve 22. The throttle valve 22 is mechanically connected to the accelerator pedal 24 (not shown). The bypass pipe 24 is arrange | positioned in parallel with the tract 20 of the suction side in which the throttle valve 22 was provided inside. In the bypass 24, a breather 26 is installed, and the actuator of the breather 26 can be controlled by the engine control device 28. The breather 26 may also be referred to as an idle regulator.

The amount of air sucked in through the suction tract 20 and the bypass tube 24 is introduced into the cylinder in the region of the cylinder head, where combustion is carried out together with the fuel.

The signals of the speed sensor 30 are transmitted to the engine control device 28 as well as the signals of the accelerator pedal position 32.

In figure 2 the process according to the invention is described in more detail in the form of a block diagram. The detected speed value 34 and the pedal position 36 are applied to the characteristic map 38 (獨: anliegen). In the characteristic map 38, the torque coefficient TQ_FAC 40 is calculated in a manner known in principle. The torque coefficient 40 indicates what ratio is required between the lower limit reference value and the upper limit reference value according to the accelerator pedal position 36. Torque coefficient 40 is compared to minimum torque 44 at process step 42. The minimum torque TQ_MIN 44 is determined based on the minimum air amount MAF_KGH_MIN 46 in the engine. In this case, the minimum air amount is preferably calculated in units of kg / h.

The process according to the invention begins with the minimum reduced cross section ARED_MIN 50 available in step 48 for the calculation of the minimum air volume 46. The value of ARED_MIN is originally calculated in a known manner and can preferably be corrected for the situation. The calculation process is further subdivided in the block circuit diagram 48. First, the reduction cross section 50 is multiplied by the temperature dependent parameter K (52), and then divided by parameter A (54) of the absorption characteristic curve. The resulting value is applied to the property map 58 as variable X 56. In addition, the second parameter Y 62 for the characteristic map 58 is determined according to the pressure 60 before the throttle valve. To do this, the pressure 60 before the throttle valve is multiplied by parameter A 54 of the absorption characteristic curve. This product divides the second parameter B 64 of the absorption characteristic curve. The resultant value is applied to the characteristic map 58 as the variable Y 62.

The output variable of the characteristic map 58 is the pressure ratio PQ 66 at the throttle valve. This pressure ratio is multiplied by the product of the pressure 60 before the throttle valve and the parameter 54 of the absorption characteristic curve. From this product, parameter B is subtracted as the second variable of the absorption characteristic curve, and as a result, the minimum amount of air is supplied to the engine. The calculation performed is based on the following equation for the minimum air mass flow at steady state.

MAF_KGH_MIN = ARED_MIN * PSI (PQ) * PRS_UP_THR * K

= PRS_UP_THR * PQ * A-B

From this equation, the equation solved by the characteristic map 58 is derived using the auxiliary variables X and Y.

X = ARED_MIN * K / A

Y = B / (A * PRS_UP_THR)

PQ = X * PSI (PQ) + Y

Physically the process is based on the idea described in more detail in accordance with FIG. 3 below. The left side of FIG. 3 shows the air mass MAF per cylinder stroke relative to the throttle valve position or the current pedal position PV. Curve "68" shows the amount of air when the bypass bleeder is completely closed, and curve "70" shows the amount of air when the bypass bleeder is fully open. These two curves show that as soon as the throttle valve opens slightly at a preset speed, the position of the bypass bleeder makes a distinct difference in terms of the amount of air available. In this respect, of course, the expert knows that the difference is further reduced by the higher rotational speed.

The diagram shown on the right of FIG. 3 shows the limit value for torque at the optimum ignition angle as a function of pedal position. If the number of revolutions is constant, the curve progression of curves "68" and "70" representing the amount of air almost coincides with the progression of the torque curves 72 and 74. If the torque is located below the curve 72 at the preset pedal position, such a situation can only be achieved by a later ignition angle. If the torque is located in the area B above the curve "74", this situation cannot be achieved. In the process according to the invention, as shown in FIG. 2, a value greater than the torque setting value 68 is transmitted from the torque value calculated based on the value “44” and the variable TQ_FAC 40 in block 42.

In order not to conflict with the idling state, a comparison is made only from the correct minimum pedal operation in the block circuit diagram 42. For this purpose the variable PV 36 is further considered in the block circuit diagram 42.

In Fig. 2 the process according to the invention is depicted in terms of the lower limit of the torque setpoint. As can be seen in FIG. 3, the process according to the invention can be suitably used for limiting the upper limit of the torque setpoint.

The present invention can provide a method for controlling and / or adjusting an internal combustion engine that provides a torque setpoint that can be realized with as advantageous fuel consumption as possible.

Claims (11)

An accelerator comprising a throttle valve and an intake tract comprising a breather in a tube parallel to the throttle valve, and an sensor mechanically coupled to the throttle valve and detecting a pedal position and a throttle valve position. In the method for controlling and / or adjusting an internal combustion engine having: Calculate a value 40 for torque as a function of said accelerator pedal position 36, A minimum value 44 of said torque is calculated relative to the reference value of the ignition angle and the injection amount, with the breather closed and the current pedal position, Comparing the calculated value 40 and the minimum value 44 of the torque to each other (42) and conveying the greater of the two torque values than the torque set value (68) for driving the internal combustion engine; Controlling and / or adjusting the internal combustion engine. Method according to claim 1, characterized in that the comparison is carried out under addition of a preset value. Method according to claim 1 or 2, characterized in that the comparison is made only if the pedal position (36) exceeds a preset minimum pedal position. An intake tract including a breather in a throttle valve and a tube parallel to the throttle valve, and a sensor 32 mechanically coupled to the throttle valve and detecting a pedal position and a throttle valve position. A method for controlling and / or adjusting an internal combustion engine having an accelerator comprising: Calculate a value 40 for torque as a function of said accelerator pedal position 36, -Calculates the maximum value for torque at the breather fully open and at the current pedal position, Preferably, under addition of a preset value, the calculated value 40 and the maximum value 44 for the torque are compared with each other (42), and the torque set value of the two values for driving the internal combustion engine; A method of controlling and / or adjusting an internal combustion engine, characterized in that a value smaller than (68) is transmitted. An intake tract including a breather in a throttle valve and a tube parallel to the throttle valve, and a sensor 32 mechanically coupled to the throttle valve and detecting a pedal position and a throttle valve position. A method for controlling and / or adjusting an internal combustion engine having an accelerator comprising: Calculate a relative required torque as a function of said accelerator pedal position 36, -Calculates the maximum torque at the breather fully open and at the current pedal position, Setting an upper reference value of the relative demand torque to a value corresponding to a maximum value or a value increased by a predetermined value relative to the maximum value, Calculating a torque setpoint to be transmitted for the drive of the internal combustion engine from the relative demand torque and the reference value. 6. Control and / or internal combustion engine according to any one of the preceding claims, characterized in that a minimum and / or maximum value of torque is determined at a predetermined ignition angle, preferably at an optimum ignition angle. Adjustment method. The internal combustion according to one of the preceding claims, characterized in that the minimum and / or maximum value of the torque is determined based on the value of the reduced flow cross section 50 at the throttle valve. Method of control and / or coordination of the organ. 8. A method according to claim 7, wherein the value of the reduced flow cross section of the throttle valve is adapted to the situation. 9. Use according to any of the preceding claims, depending on the temperature of the intake air, the parameter characterizing the engine absorption characteristic curve, the pressure 60 before the throttle valve and the value 50 of the reduced flow cross section. A method of controlling and / or adjusting an internal combustion engine, characterized in that the minimum possible amount of air or the maximum amount of air is determined. 10. The minimum and / or maximum pressure ratio 66 at the throttle valve is determined using a characteristic map 58, and 2 as input variables used in the characteristic map. Parameters 56 and 62 are used, which in turn relate to the temperature variable of the intake air, to characterize the engine absorption characteristic curve, to the pressure 60 before the throttle valve and to the reduced flow cross section. A method of controlling and / or adjusting an internal combustion engine, characterized in that it depends on the value (50). Method according to claim 10, characterized in that the minimum and / or maximum air quantity available is determined from the minimum and / or maximum pressure ratio at the throttle valve.