WO2019121690A1

WO2019121690A1 - Method for complying with legal limiting values for emissions when operating a motor vehicle with an internal combustion engine

Info

Publication number: WO2019121690A1
Application number: PCT/EP2018/085510
Authority: WO
Inventors: Dietmar Ellmer
Original assignee: Continental Automotive Gmbh
Priority date: 2017-12-19
Filing date: 2018-12-18
Publication date: 2019-06-27
Also published as: DE102017223209A1

Abstract

A method for complying with a legal limiting value for at least one material which is emitted during the operation of a motor vehicle with a drive system with an internal combustion engine, wherein a mass of at least one material which is emitted by the internal combustion engine per combustion process is calculated as a function of an operating state of the drive system.

Description

description

Method for compliance with legal limits for emissions during operation of a motor vehicle with an internal combustion engine

The operation of motor vehicles with internal combustion engines is subject to strict legislation regarding the emissions caused by combustion. Among other things, the legislator requires compliance with legally prescribed emission limits in real operation and a reduction in CO2 emissions and fuel consumption.

In addition, there are system-specific goals (optimization criteria) that determine the application of a system (component protection, component wear, durability, comfort and driving performance.

These goals are partially in conflict with the operation of the internal combustion engine. For example, in a diesel vehicle with a calibration which is designed for a C0 ₂ minimum, as a rule the NOx raw emission output increases. This conflict of objectives can only be resolved to a limited extent by innovative exhaust aftertreatment.

In addition, in real ferry operations there are driving conditions or constraints where assessment of the given limit values is not possible or useful, and therefore exempted from the legislation, or where a rating is not required.

The emission limit values prescribed and to be observed by the legislator are previously given in mass per distance traveled (kilometers), which must also be observed during real ferry operations in the field. In order to take account of all boundary conditions that occur in reality, such as inclines, ambient temperatures, vehicle load variations, an (emission) reference to the given power and speed is emerging in (future) legislation. Mathematic It uses filters that make it possible to assess the representation of the profile driven and the emissions emitted by the legislator.

The invention is based on the object to resolve the conflict of goals in accordance with the legal requirements.

The object is achieved by a method and a control device according to the independent claims. Advantageous developments are given in the dependent claims.

An inventive method relates to the operation of a motor vehicle with a drive system with at least one internal combustion engine. This can be, for example, a purely internal combustion engine drive system or even a hybrid drive system with at least one combustion engine and one electric motor as the traction engine. In order to comply with at least one predetermined limit value for at least one emitted during operation of the motor vehicle with a drive system with an internal combustion engine, the mass of the at least one combustion engine per Ver combustion process emitted substance is calculated according to an operating state of the drive system according to the invention. The limit can be prescribed by law.

When operating an internal combustion engine to drive a

Motor vehicle arise various products, which are emitted mainly via the exhaust system of the vehicle. These emitted substances sometimes have negative effects on the environment, the climate, or the health of humans and animals. Accordingly, some of these substances are referred to as pollutants. For substances regarded as harmful, legislators have set limits in some cases which must not exceed the emissions during operation of a vehicle. The process according to the invention is provided in particular for substances designated as pollutants, for which limit values are provided by the legislature. However, the invention is expressly not restricted to pollutants but can be applied to all substances emitted by the combustion engine, even if a harmful effect at the time of notification is not known.

For the different substances emitted during operation of the internal combustion engine, different limit values can be defined. The composition of the emissions, i. The ratio of the emitted masses of the substances to one another depends, among other things, on the fuel used and on an operating state of the internal combustion engine. The calculation according to the invention of the emitted mass of a substance therefore takes place as a function of the operating state of the drive system. Wherein the operating state of the drive system comprises at least one loading operating state of the internal combustion engine.

The operating state of the drive system is characterized, inter alia, by an instantaneous power, torque, or rotational speed and / or temperature of the drive components. It can be differentiated between stationary or dynamic ferry operation. The current state data are übli cherweise available in an engine control and can be evaluated to implement the method according to the invention.

Preferably, it is assumed for the calculation of the emitted masses that the entire drive system is in a perfect condition. The calculation is estimated, preferably based on a corresponding model that has been previously implemented.

Therefore, an advantageous variant of the method according to the invention also comprises, as a preceding step, the implementation of a model for calculating a mass of at least one substance emitted by the internal combustion engine per combustion process as a function of an operating state of the drive system.

The calculation of the substances emitted per combustion process is estimated. The accuracy of the calculation can be increased if, in addition to the operating state of the drive In addition, environmental parameters and / or information about the resources used are taken into account. Environmental parameters may be, for example, information about a prevailing atmospheric pressure, temperature or humidity. Additionally or alternatively, the Be used operating means, such as the quality of the fuel used to be considered.

To further increase the accuracy of the calculation, additional sensor data can be taken into account, which provide a conclusion on the actual emission behavior. Thus, for example, the nitrogen oxide output can be included in a measured value determined by a NOx sensor. The consideration of the measured values can either be incorporated directly into the calculation of the mass of material emitted, or such measured values can be used for model matching to correct the implemented model.

With the method according to the invention raw emissions can be expected be. Preferably, however, a catalyst efficiency is taken into account in the calculation. For this purpose, the values for raw emissions estimated using the calculation can be linked to a catalyst efficiency. This can be taken into account, for example aging effects of the catalyst. A dependency on the aging process of the catalyst can also be integrated directly in the calculation model so that the model directly calculates post-cat emissions.

Legal limits for limiting emissions of a particular substance are generally not applied to instantaneous values, but to averaged values. For an evaluation of the emissions in relation to legally prescribed limit values, the calculated masses of at least one substance emitted by the internal combustion engine per combustion process are therefore summed over all relevant combustion processes in a predefined interval, in accordance with an advantageous development of the method according to the invention. The resulting sum is related set to a reference characterizing the interval. This results in a specific value (MAX-IST) for the masses emitted.

For example, the interval is characterized by a length of a distance traveled, for example the last traveled x km, where x may be 10, 50 or 100, for example. The interval may also consist, for example, of a total distance or a partial length of the current journey. The calculated emissions of all combustion processes within this traveled route are then preferably summed up. The reference characterizing the interval is then in each case the length of the route traveled in the interval. Then it is then divided by the length of the distance traveled to obtain a MAX-IST value. The calculated MAX ACTUAL value thus corresponds to an average emission value per distance traveled in the relevant interval.

However, the interval could also be temporally characterized, e.g. by a journey time or any other characteristic technical quantity that reflects the use of the drive. Further examples of this are a power or CO 2 reference, such as according to the current "Emroad" method.

Preferably, all combustion events are summed up in the relevant interval. However, it could be that certain situations occur, such. For example, visit a workshop where irregular emissions occur, which are not considered for the evaluation. Therefore, it is envisaged to add only the relevant combustion processes in the relevant interval. Preferably, however, all combustion events within the interval are relevant. Only in exceptional cases should individual combustion processes be disregarded in accordance with statutory regulations. It may also be prescribed by law for the determination of average emissions a special algorithm. According to an alternative development of the method according to the invention, the specific value (MAX-IST) for a mass of a substance emitted during operation of the vehicle is then calculated in accordance with an algorithm (for example prescribed by the legislator). For this purpose, the calculated using a method according to the invention masses of the combustion engine emitted by combustion engine per combustion material are also based on. For example, an average movement cycle (moving average) value can be specified for the evaluation of the emissions during operation, the so-called RDE (Real Driving Emission).

The thus calculated MAX-ACTUAL VALUE is then preferably a maximum value, which was delivered in the worst case to the environment. The MAX ACTUAL value thus corresponds to a maximum output of the considered substance per kilometer, or per reference size.

In the calculation of the MAX ACTUAL value according to one of the two variants described, an initialization of the MAX ACTUAL value is preferably carried out on the basis of the preceding drive cycle or a previously defined defined route. This can be determined by further parameters which are relevant for emission technology, such as e.g. the shutdown duration or operating parameters of the system will experience an extension of the definition.

The thus calculated maximum pollutant emissions per reference variable (MAX actual value) is then compared according to a preferred development with the predetermined limit value. If the calculated MAX-IST value for the emissions of the substance is greater than or equal to the predetermined limit and / or greater than a predetermined threshold below the predetermined limit, measures are preferably taken to reduce the emission of the substance. A predetermined threshold value below the (eg legal) limit value can be predetermined in order to preferably mark a critical range below the limit value. If this predetermined threshold has been exceeded below the limit, the MAX ACT value is already close to the limit and measures will be taken to reduce the

Emissions advantageous to avoid exceeding the limit from the outset.

Suitable measures for limiting emissions may be, for example, a limitation of the operating range, displacement of a current operating point or a shift of drive power to other less polluting drive subsystems. In hybrid vehicles can be used for example reinforced the electric motor. Other measures include the temporary shutdown of subsystems, such as the air conditioning or ventilation, etc. Advantageously, the measures can be strengthened to the extent in which increases the currently driven route.

If the limit value and / or the threshold value have already been exceeded, the measures are preferably intensified to the extent that the limit value or the threshold value is exceeded. In this way you can react to how critical the limit violation is or how close the MAX-ACTUAL value is to the limit value violation.

In order to anticipate exceeding the limit value, according to a preferred development, a tendency of the MAX actual value is recorded and determined, and the measures for reducing the emissions are increased or reduced as a function of this tendency. Thus, if the MAX ACTUAL value increases and is close to a limit violation, the measures can be stepped up. If the

MAX-IST value is already decreasing or if it is probable that the limit value or the threshold value is undershot, the measures can be reduced. This can avoid unnecessary performance losses or restrictions of comfort if this is not required for compliance with the legal limit.

Further efficiency improvement in the initiation of action can be achieved by additionally considering predicted information on future journeys. By way of example, route information about preceding journeys may be present, for example by entering a destination in a navigation device. For repeated journeys, information about journeys ahead can also be obtained through machine learning.

Tracking systems or navigation devices may also be used to predict future trips to a limited extent without destination entry. For example, when driving uphill on a mountain pass is likely to take place a subsequent downhill. Further information about the routes ahead can be obtained, for example, via a communication between vehicle and infrastructure, vehicle to other vehicles or vehicle to a backend. In addition to information about the upcoming routes and legs, weather information and weather forecasts, for example, may also be taken into account when adjusting the measures to reduce emissions.

The method according to the invention is preferably carried out in an in-vehicle control device. The control device may be a central control device of the vehicle, in which, for example, a motor control is integrated in. The control device can also initiate measures to reduce emissions. There is no intervention by a driver. On the other hand, additional measures can be initiated by the driver if the driver is aware that a limit is exceeded, and in addition, the acceptance of the automatically initiated measures can be increased. Therefore, preferably the specific MAX ACTUAL value, which designates the maximum substance emission per kilometer and / or the initiation of measures or proposed measures for reducing the emissions to the driver of the vehicle are shared. This can be done acoustically or haptically or visually via suitable interfaces. A message about external devices such as smartphones, tablets and external displays or speakers is conceivable.

A control device with a processor unit, which is adapted to carry out the method according to the invention, as well as a motor vehicle with a corresponding Steuervor direction are independent aspects of the invention.

In the following, the invention will be explained by way of example with reference to the figures. They show schematically:

Figure 1: A motor vehicle with an internal combustion engine and a control device for carrying out the method according to the invention; and

Figure 2 is a flowchart of a preferred Ausfüh tion variant of the method according to the invention.

1 shows a motor vehicle 100 with a drive system 200 with an internal combustion engine 201 and with a Steuervor device 300, which is adapted to carry out the method according to the invention.

The sequence of the method according to a first embodiment variant is shown in FIG.

In step 10, a model for calculating the mass of a substance emitted per combustion process is implemented. In step 20, the calculation is based on the implemented model taking into account environmental parameters, such as Temperature and humidity and considering a fuel quality. The calculation is done according to the implemented model as post-cat emission. In step 30, the calculated emissions per combustion process are summed over all combustion events of the last x km traveled, xz.B. 100 km can be. In step 40, the distance x km is divided to obtain a specific MAX-IST value.

A comparison of the calculated MAX-IST value is performed in step 50. In step 60, a case distinction is made: If the calculated MAX-IST value is below a threshold value S below the legal limit value G, the method is ended, or it is continued and updated again in step 20.

If, however, it is determined in step 60 that the calculated MAX-IST value is above the threshold value S, then measures for reducing emissions are initiated in step 70. At closing, the method is continued with step 20.

Claims

claims

Anspruch [en] A method for maintaining at least one predetermined limit value (G) for at least one substance emitted during operation of a motor vehicle (100) with a drive system (200) with an internal combustion engine (201)

with the steps:

- Calculating (20) a mass of the at least one of the internal combustion engine (201) per combustion process emit-oriented substance as a function of an operating condition of the drive system.

2. The method according to claim 1, with the preceding step:

Implementing a model for calculating a mass of at least one substance emitted by the internal combustion engine (201) per combustion process as a function of an operating state of the drive system.

3. Method according to one of the preceding claims,

wherein calculating a mass of at least one of the internal combustion engine (201) per combustion process emit-oriented substance

in addition, depending on environmental parameters and / or used resources.

4. Method according to one of the preceding claims,

wherein the calculation of a mass of at least one of the internal combustion engine (201) per combustion process emit-oriented substance additionally takes place as a function of sensor data, which provide conclusions on the actual emis sion behavior.

5. The method according to claim one of the preceding An

claims,

wherein calculating a mass of at least one of the internal combustion engine (201) emit per combustion process Substance additionally takes place under consideration of a catalyst efficiency.

6. Method according to one of the preceding claims,

with the further steps:

- summation of the calculated masses of at least one of the internal combustion engine (201) per combustion process emitted substance over all relevant combustion processes in a predetermined interval; and

- relating the resulting sum to a reference characterizing the interval, resulting in a specific value (MAX-IST) for the emitted

Mixture results.

7. The method according to any one of claims 1 to 5,

with the further step:

- Calculating a specific value (MAX-IST) for an emitted during operation of the vehicle (100) mass of a substance according to a predetermined algorithm on the basis of a method according to any one of claims 1 to 5 calculated masses of the internal combustion engine (201) per combustion process emitted substance.

8. The method according to claim 5 or 6 with the other

Steps:

Comparing the calculated MAX-IST value with the predetermined limit value (G) for the emitted substance; and

- If the calculated maximum actual value is greater than or equal to the predetermined limit value (g) and / or greater than a predetermined threshold value (S) below the predetermined

Limit value (G) is,

- Take measures to reduce the emission of the substance.

9. The method according to claim 8, wherein

if the limit value and / or the threshold value are exceeded, the measures are intensified to the extent that the limit value (G) or the threshold value (S) is exceeded becomes .

10. The method according to any one of the preceding claims 8 or 9, wherein a tendency of the specific MAX-IST value is determined and the measures are increased or decreased depending on the tendency.

11. The method according to any one of claims 8 to 10,

the measures being adjusted according to predicted information about future journeys.

12. The method according to any one of claims 6 to 11, wherein the specific value (MAX-IST) for the emitted mass and / or measures to reduce emissions to a driver of the vehicle (100) are communicated.

13. Control device (300) with a processor unit which is set up to carry out a method according to one of the preceding claims.

14. Motor vehicle (100) with an internal combustion engine (201) and with a control device (300) according to claim 13.