SE1350825A1 - Analysis of a function for at least one system related to an internal combustion engine - Google Patents

Abstract

Summary A procedure and system for analyzing a function of at least one system related to an internal combustion engine in a vehicle is described. The system comprises a motor load unit, which is arranged to build up a motor load L for the vehicle, where this motor load L has a size suitable for the analysis of the function and where the motor load unit is arranged to use at least one service braking system in the vehicle when building the motor load L. The invention also comprises an analysis unit, which is arranged to perform the analysis of the function of the at least one system for a period of time, ionary, where the built-up motor load L is essentially maintained stationary during the period of 'stationary by continuing to use the at least one service braking system.

Description

TECHNICAL FIELD The present invention relates to a process for analyzing a function of at least one system related to an internal combustion engine in a vehicle according to the preamble of claim 1. The present invention also relates to a system for a combustion engine. analysis of a function for at least one system related to an internal combustion engine in a vehicle according to the preamble of claim 22, and a computer program and a computer program product, which implement the method according to the invention.

Background The following background description is a description of the background to the present invention, and thus does not necessarily have to be prior art.

Internal combustion engines, such as internal combustion engines included in vehicles, are powered by fuel, such as diesel, petrol, ethanol, or mixtures of such industries with each other and / or with additives of various kinds. The fuel is provided to the combustion engine by a fuel system, including one or more fuel tanks and devices which transport the fuel from the fuel tanks to the combustion engine. The devices which transport the fuel to the engine may comprise, for example, lines for transporting the fuel to the vehicle, one or more pumps, which may be divided into legal or high-pressure circuits, filters, couplings, and other devices for fuel transport. The fuel is injected into the engine cylinders by an fuel injection system which includes an injection means, also called an injector or injector, per 2 cylinders. The injection means can, for example, be supplied with fuel by a common rail unit, which supplies pressurized fuel to all the injection means, or by separate units with pressurized branch for each injection means.

The internal combustion engine also needs to be supplied with air for the combustion of the fuel, which can be done, for example, by a turbo unit.

During the combustion of the fuel in the engine, exhaust gases are formed. To warn the environment and people, as well as to meet emissions requirements met by authorities, the exhaust gases from the internal combustion engine are purified in an exhaust gas treatment system before they are emitted from the unit containing the engine, for example a vehicle.

Brief Description of the Invention It is desirable that the same amount of fuel be injected into each of the engine cylinders when the engine is started to receive an even torque from the engine.

However, the injectors often inject different amounts of fuel into the cylinders due to individual variations of the injectors. Such individual variations may be due to small differences in the manufacture of the respective injection means.

The injection means are also subjected to a mechanical wear over time, for which an average wear for the entire population of injection means can be determined. In some cases, the injection system may also correct for this wear and tear to limit its impact on the driving of the vehicle. However, individual differences between the wears of individual injectors may also exist due to the fact that the injectors have individual properties, which may be due to manufacturing differences between the injectors and / or in the wear of the injectors. In particular, the different wear behaviors of the injection means, which result in individually different wear of the injection means, are responsible for determining and correcting for previous known solutions.

Since the injection means are subjected to mechanical wear over time, problems can also arise if one or more injection means are replaced in the vehicle. The new injection member (s) mounted in the vehicle will therefore not be worn and will behave differently from the injection members which have not been replaced.

The various properties that can arise for the injection means mean that the torque provided by the internal combustion engine becomes uneven. This is schematically illustrated in Figures 1a and 1b, in which the speed a, which is related to the torque M of the engine, of an eight-cylinder four-stroke engine is shown as a function of the crank angle of the engine shaft. Figure 1a shows a schematic example of an engine with injection means with substantially equal properties, i.e. Atta injection means which inject substantially the same amount of fuel into each cylinder, whereby the speed increases and decreases substantially the same when injecting fuel into each other. the cylinders. If, for example, the injection means are manufactured with substantially equal properties and then wear substantially in the same way, the speed according to Figure 1a can thus be obtained.

If one or more injection means injects a deviating amount of fuel into the respective cylinder, an uneven torque is obtained, as illustrated in Figure 1b. In the schematic example in Figure 1b, the injector in the first cylinder injects too much fuel, which is slightly more fuel than other injectors, which causes the speed to increase too much in the injection for this cylinder and also that the speed of at least the second cylinder is affected so that even its speed becomes too high. Then the speed of the injections in the subsequent cylinders decreases again until the injections of the next cycle begin. The example shown in Figure 1b would give a torque unevenly supplied by the engine, which has a negative effect on the performance of the vehicle.

In addition, the uneven moment can interact with resonances in, for example, a vehicle, such as resonances in the driveline, which means that the resonances and the uneven moment reinforce each other and result in relatively large oscillations due to the driveline and / or the engine torque. Fluctuations for the driveline and / or torque can be assumed to be relatively large and will be experienced by a driver of a vehicle as annoying and / or unpleasant.

The function of the exhaust gas treatment system can also deteriorate over time, for example due to clogging of particulate filters, or due to reduced efficiency of one or more of the catalysts present in the exhaust gas treatment system. A common fault in exhaust gas treatment systems is that the nitrogen oxide sensors in the exhaust gas treatment system do not work properly. Accumulation of reducing agents, such as urea, in the catalyst can also be dangerous. This results in a premature purification of exhaust gases formed during combustion in the engine, which in some cases can force an outage due to non-compliance with regulatory requirements for emissions.

The air supply to the engine, for example the supply of a turbocharger or another air supply device for creating compressed air for the combustion of the engine in the cylinders, can also be reduced over time, which reduces the engine performance. One or more boost pressure sensors can Oven give incorrect values. The declining performance of the engine and / or the incorrect boost pressure values can in turn lead to sub-optimized controls of various systems in, for example, a vehicle, such as a sub-optimized cruise control, which can have negative effects, such as increased fuel consumption and / or increased exhaust emissions and / or or a disjointed tub experience.

Thus, one or more systems related to the combustion engine of a vehicle, such as the fuel injection system, the exhaust gas treatment system and / or the air supply system, may have an unsatisfactory and / or substandard function, which adversely affects the vehicle's behavior and / or how the vehicle is experienced by a driver.

To be able to know that these systems related to the combustion engine have a satisfactory function, a reliable method is required for analysis / diagnosis of the function. Such an analysis may be necessary after a period of operation. Even after replacement of components, as after replacement of a faulty injection member, it may be appropriate to analyze the function of the new component to verify that the fault has been remedied by the replacement of the component.

One way to perform this analysis / diagnosis of the systems Or to use in the vehicle built Monitoring / analysis / diagnosis systems that normally monitor the systems in the vehicle. Many built-in Monitoring / Analysis / Diagnosis systems require that the Monitored system be subjected to a high load for a reliable analysis / diagnosis to be performed.

An earlier application for achieving this high load has been to drive the vehicle heavily loaded on an uphill slope for a relatively long period of time. This loading has a problem in that it requires things for a small access slope, which is not always available at a workshop. For example, in regions or countries with little topographical variation, for example in the country Holland, it can be difficult for a suitable uphill slope to carry out the analysis of why expensive workshop and downtime is spent transporting the vehicle to a limp uphill slope. In other cases, this is a costly and time-consuming method of achieving the high load.

According to other known solutions, auxiliary brakes in the vehicle have been used to compensate for the high load. Liar has retarder brakes, where resistance is created by activating oil, and / or exhaust brakes, where resistance is created by closing a spike in the exhaust treatment system, which means that the exhaust flow is slower, activated while the engine gives full torque to create the high load.

Only certain vehicles are equipped with retarder brakes, which means that the method that includes retarder braking cannot be applied to a large number of vehicles. If the vehicles equipped with a retarder also lose a considerable amount of cooling of the retarder, this is done by creating the high load in this way, which can lead to a high load on the cooling system. Retardation braking can also lead to oscillations in the driveline, which can disrupt the analysis and make the result incorrect, or at least not reliable. Relatively many vehicles do not have exhaust brakes, which means that the method that includes exhaust braking is not applied to all vehicles either. Exhaust braking can also lead to oscillations in the driveline, which can be great for analysis. In addition, it can be black, sometimes impossible, and at least take time to achieve the high load required by exhaust braking.

It is therefore an object of the present invention to provide a method and a system for analyzing a function of at least one system related to an internal combustion engine in a vehicle which at least partially solves the above-mentioned problems.

This object is achieved by the above-mentioned method according to the characterizing part of claim 1. The object is also achieved by the above-mentioned system according to the characterizing part of claim 22 and by the above-mentioned computer program and computer program product.

According to the present invention, an engine load L is built up of the vehicle by utilizing at least one service brake system in the vehicle, where this built-up engine load L was a size suitable for the analysis of the function. Then the analysis of the function is performed, it receives at least one system for a period of time Tstationaryr during which the built-up motor load L is essentially maintained stationary during the time period 'stationary by continuing to use the at least one service braking system.

By utilizing the method according to the present invention, a substantially stationary motor load L is obtained during the analysis, which means that transients of various kinds can largely be avoided in the systems to be analyzed. This results in a high-quality, robust and reliable analysis of the 8 systems, since the analysis is performed under stationary conditions for the systems to be analyzed.

According to the present invention, one or more service brake systems are used to build up and maintain the engine load L, which means that the analysis according to the present invention can be carried out in all vehicles, since the construction and maintenance of the engine load L can be carried out on all vehicles which include service brakes. all vehicles.

In addition, the use of the service brakes provides a more reliable analysis than previous known solutions, since the use of the service brakes provides an accurate and reliable structure of the motor load L, as well as an accurate and reliable maintenance of the motor load L at its constructed value.

According to an embodiment of the invention, the analysis control unit, which controls the method according to the present invention, communicates and uses at least one control unit for the service brake system, which may for instance consist of at least a so-called EBS control unit (Electronic Brake System), for creating and maintaining the motor load L Thus, the present invention can utilize in vehicles already existing braking systems and control units for these braking systems, which minimizes the addition in complexity in implementing the present invention. In other words, reliable analyzes can be performed by utilizing the existing monitoring / analysis / diagnosis system in the vehicle, which has implementation and cost advantages.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further elucidated below with reference to the accompanying drawings, in which like reference numerals are used for like parts, and of: 9 Figures 1a-b schematically show examples of torque / speed in an engine for injection means having similar and different properties, Figure Figure 2 schematically shows an exemplary vehicle, Figure 3 shows a flow chart of the method according to the present invention, Figure 4 shows an example of a vessel case in which the present invention is used, Figure 5 schematically shows a control unit according to the present invention.

Description of Preferred Embodiments Figure 2 schematically shows an exemplary vehicle 100 which may incorporate the present invention. The vehicle 100, which may be a passenger car, a truck, a bus, or another vehicle, includes a driveline, which transmits power to drive wheels 111, 112 in the vehicle 100. The driveline includes an internal combustion engine 101, which in a conventional manner, via a shaft 102 on the internal combustion engine 101 is connected to a gearbox 103 via a coupling 106. Of course, the vehicle's driveline may also be of another type, such as a type of conventional automatic transmission, of a type with a hybrid driveline, etc.

The internal combustion engine 101 is driven by fuel, which is provided by a fuel system 120 comprising, inter alia, one or more fuel tanks and devices 125 which transport the fuel from the fuel tanks to the engine 101, and a fuel injection system which is arranged to inject fuel into the engine cylinders with a number N injection means 121_12N. , where N may be, for example, the number 5, 8, 12, or another appropriate number for the number of cylinders in the engine 101. The fuel transport devices 125 shown are very schematic, but may include, for example, one or more lines for transporting the fuel in the vehicle, a or several pumps, which may be divided into respective high pressure circuits, filters, couplings, and other devices for industry transport. The internal combustion engine 101 is controlled by the vehicle control system via a control unit 140, which is schematically illustrated in Figure 2. The fuel system is controlled by the vehicle control system via a control unit 140, which is schematically illustrated in Figure 2 as the same control unit 140 which controls the combustion engine, but which can be arranged separately. this control unit 140. The control unit 140 may be included in, or cooperate with, an EMS (Engine Management System) circuit in the vehicle.

The combustion engine 101 needs Oven stuffed with air for the combustion of the industry. This air can be supplied to the engine 101 by a supercharger 160, which may for example be a turbocharger which may be driven by a turbine, or flake other type of air compressor driven by another unit On a turbine, for example by the internal combustion engine 101 cm the air compressor Or connected to the crankshaft .

A shaft 107 emanating from the gearbox 103 drives the drive wheels 111, 112 via an end shaft 108, such as e.g. a conventional differential, and drive shafts 104, 105 connected to said end shaft 108.

Exhaust gases created by the engine 101 during its combustion of the fuel are purified by an exhaust gas treatment system 130 before being discharged from the vehicle. The exhaust gas treatment system 130, which has been very schematically illustrated, may comprise one or more of 11 particle filters, oxidation catalysts, reduction catalysts. The purification of the exhaust gases is controlled by a control unit 140, which controls, for example, the dosing of reducing agents, which may include, or be converted to, ammonia, such as urea. The control unit which controls the exhaust gas treatment system is schematically illustrated in Figure 2 as the same control unit which controls the combustion engine and / or the fuel system 120, but which can also be arranged separately from this control unit 140.

The vehicle also comprises at least one having schematically illustrated service brake system 150, comprising a steering unit 155, which in Figure 2 is illustrated as two separate steering units 155 for the tram and rear wheels 111, 112, 113, 114, respectively, but which can also be constituted by a common steering unit for the tram and rear wheels. The service braking system 150 also comprises one or more service braking devices 151, 152, 153, 154 which are arranged in connection with two or more of the vehicle's wheels 111, 112, 113, 114. The service braking devices 151, 152, 153, 154 are controlled by the control unit 155, which in Figure 2 is schematically illustrated as separated from the control unit 140 which controls the combustion engine and / or fuel system 120 and / or the exhaust treatment system 130. However, the control unit 155 for the cruise control devices may also be incorporated in the control unit 140 which controls the internal combustion engine and / or fuel system 1 and / or the exhaust treatment system 130.

The control unit 140 is connected to the engine 101, and to the service brake system 150, and to one or more of the exhaust gas treatment system 130 and the fuel system 120. According to the present invention, the control unit 140 can communicate with an analysis control unit 170, which includes an engine load unit 171 and an analysis unit 172. 2 are illustrated as separate units, but which can also be implemented in a common unit. The motor load unit 171 and the analysis unit 172 are described in more detail below. Analysis control unit 170 can also be arranged as incorporated in the control unit 140.

Figure 3 shows a flow diagram of a method according to the present invention, the viii story of the method for analyzing a function of at least one system related to the combustion engine.

In a first step 301, the procedure starts.

In a second step 302 of the procedure, for example by using the motor load unit 171 described below, a motor load L is built up the vehicle 100. The construction of the motor load L comprises the use of at least one service brake system 150 in the vehicle, which may comprise one or more service brake devices 151. 152, 153, 154. The motor load L thus created has a suitable size for the analysis, which may be different for different types of analyzes. Thus, the engine load L is created by the driving force created by the engine 101 being counteracted by the service brake system 150 in the vehicle.

In a third step 303 of the procedure, for example by using the analysis unit 172 described below, the analysis of the function of the at least one system during a time period Tstationary is performed. According to the present invention, the motor load L constructed in the second stage 302 is essentially maintained stationary during the time period T stationary when the analysis is performed. The maintained engine load L is achieved by a continued use of the at least one service braking system. Thus, the service brake system 150 continues to counteract the driving force created by the engine 101 in such a way that the engine load L is caused to maintain the appropriate size for the analysis during the time period Tstationary when the analysis is performed. Using the method according to the present invention, a substantially stationary motor load L is obtained during the analysis, the viii saga during the time period T stationary. This is very advantageous in the analysis of the at least one system, since the substantially stationary motor load L allows transients of different types to star part can be avoided in the systems to be analyzed. This significantly increases the possibilities for a reliable analysis.

There are often connections and / or cross-connections between different parameters in a system, and also between different parameters in different systems, in a vehicle. This means that changes due to transients have the motor load L can propagate sip in an often harmless way, and can also create and / or amplify resonant oscillations in the vehicle. This makes it very difficult to determine whether the characteristics of the analysis result for a system have originated from the system itself or from a transient has the motor load L. In short, transients for the motor load L cause a great deal of uncertainty about the reliability of the analysis, which is described more below.

According to the present invention, therefore, the analysis must instead be carried out under a substantially stationary motor load L. This is per a high-quality and reliable analysis of the one or more systems, since the analysis is carried out under stationary conditions for the systems.

According to the present invention, as described above, the service brake system 150 is used to build up and maintain the engine load L. This has an advantage in that this construction and this maintenance of the engine load L can be performed on essentially all vehicles, since essentially all vehicles comprise service brakes. This has a major advantage over previous known loads, in which different types of auxiliary brakes, such as 14 retarder or exhaust brakes, which are present in relatively few vehicles, are used to create load.

In addition, the use of the service brakes provides a more precise and reliable construction of the motor load L, as well as a more precise and reliable maintenance of the motor load L at its built-up value. This is because the service brakes can provide more braking force than the auxiliary brakes and the service brakes are located at the wheels 111, 112, 113, 114. Since the driveline is not completely rigid in a vehicle, braking by means of auxiliary brakes can give driveline oscillations and varying braking force. Using the feed brakes as a hazardous invention therefore provides an increased accuracy for the analysis compared to previously known solutions which use auxiliary brakes.

According to an embodiment of the present invention, the system to be analyzed emits a fuel injection system for the internal combustion engine, the analysis being used to create a diagnosis for at least one injection means 121_12N in the fuel injection system.

The assay of the present invention can, according to one embodiment, be used to ensure that the fuel injection system functions satisfactorily after at least one injection member 121_12N has been replaced. A replacement of injection means 121_12N can take place after the injection means 121_12N has been worn in so much that an uneven torque is provided by the engine, see for example the illustration in figure 1b, whereby the vehicle is taken to a workshop for replacement of injection means 121_12N.

After the change Is it important to make sure that a torque is provided by the motor, that is to say that the torque, for example, has an appearance corresponding to that in figure 1a. Then the procedure according to the present invention is suitably carried out. The analysis can be performed in a workshop test, which is performed in a workshop environment.

Even when adapting at least two injection means 121_12N in said fuel injection system, the present invention can be used. The analysis according to the hazardous father is thus used to see if one or more of the injection means 121_12N are to be adjusted to be adapted to other injection means 121_12N in order to achieve a substantially uniform moment as shown in figure 1a. This analysis, with subsequent adaptation, can be performed relatively soon after the replacement of one or more injection means 121_12N, or also after a long period of operation of the vehicle after changes have been made in the fuel injection system.

According to an embodiment of the present invention, the system to be analyzed is an exhaust gas treatment system 130 arranged to clean exhaust gases from the internal combustion engine 101, the analysis of the exhaust gas purification system 130 being used to create a diagnosis for at least one component of the exhaust gas treatment system 130.

Exhaust gas treatment systems 130 in modern vehicles may include a variety of components, such as a reduction catalyst, a particulate filter, an oxidation catalyst, and an abrasive catalyst. The exhaust gas treatment system 130 may also include additional components, such as means arranged for dosing additives, for example urea, into the exhaust gases, or other types of catalysts.

According to the embodiment, the analysis of the exhaust gas treatment system 130 is used to ensure that the exhaust gas treatment system 130 functions satisfactorily, for example after at least one component of the exhaust gas treatment system 130 has been replaced, or after a long period of operation of the vehicle after changes have been made to the exhaust gas treatment system 130. workshop test, which is performed in a workshop environment.

Exhaust gas treatment system 130 generally needs to achieve a relatively high operating temperature for all components to be active so that efficient exhaust gas purification can be achieved. Being able to carry out the analysis under high and precise engine load L, which is possible by utilizing the present invention, is therefore advantageous because the high engine load causes the operating temperature of the exhaust gas treatment system to be sufficiently high.

In addition, substantially constant exhaust surfaces and / or constant emission levels as well as substantially constant exhaust and / or catalyst temperatures are desirable in certain analyzes and / or diagnoses for exhaust gas treatment systems. Since the present invention can provide analysis / diagnosis under stationary conditions, it also allows for analysis / diagnosis at substantially constant exhaust flow and / or substantially constant emission levels and / or substantially constant exhaust temperatures and / or substantially constant catalyst temperatures.

According to one embodiment of the present invention, the system to be analyzed is provided by an overcharger 160 which compresses air entering the combustion engine 101.

The supercharger may be considered to be a turbine-powered device, such as a turbocharger, or another suitable and substantially arbitrary type of air compressor driven by another unit into a turbine. For example, the air compressor can be driven by the engine. Here, the present invention can be used to make a diagnosis of the supercharger 160. According to the embodiment, the analysis of the supercharger is used to ensure that the function of the supercharger is satisfactory, for example after the supercharger 160 has been replaced, or after a long period of operation of the vehicle. The analysis can be performed in a workshop test, which is performed in a workshop environment.

Engines can have one or more pressure sensors which supply the boost pressure. The analysis of the supercharger can also be used to identify faulty pressure sensors. For example, an analysis at a high stationary engine load L, and since the engine is equipped with two or more pressure sensors, gave one and the same relatively high boost pressure for each of the two or more pressure sensors. If the charging pressure fed by the two or more sensors differs, a diagnosis can be made which states that the sensor fault is dangerous. This analysis can also be used to diagnose a leak in the supercharger.

The analysis of the function of at least one system is controlled according to an embodiment of at least one analysis control unit 170. The analysis control unit 170 is arranged to communicate with at least one control unit 140 of the at least one system 120, 130, 160 to be analyzed.

The analysis control unit 170 comprises a motor load unit 171 and an analysis unit 172. The analysis control unit 170, more particularly the motor load unit 171, is arranged to communicate with at least one control unit 155 of the front brake system 150, which can be performed by at least one so-called Electronic Brake System. Thus, the present invention can utilize already existing braking systems in vehicles and control systems for braking with the front brake, which means that the addition in complexity through the implementation of the present invention becomes small. According to one embodiment, the motor load unit 171 provides motor load L and then maintains substantially stations during the time period. The stationary cra analysis according to the present invention is performed by requesting a braking torque M-brake of the at least one control unit 155 for the service braking system 150.

The analysis control unit 170 thus produces the motor load L and this built-up motor load L essentially maintains stations during the analysis according to the present invention. According to one embodiment, this is accomplished by the analysis control unit 170 by requesting a wheel speed vwheel from the EBS control unit 155 for the at least one service brake device 151, 152, 153, 154 in the service brake system 150.

According to an embodiment of the present invention, the suitable size of the substantially stationary built-up motor load L constitutes a high motor load L, which is thus maintained and used in the analysis. This high engine load L may have corresponded to approximately 80-100% of a maximum possible engine load Lmax for the vehicle / engine, and may dangerously correspond to 90% -95% of the maximum possible engine load Lmax. The maximum possible engine load Lmax depends on a speed for the internal combustion engine 101. As mentioned above, many built-in monitoring / analysis / diagnosis systems require that the system being monitored is subjected to a high load in order for a reliable analysis / diagnosis to be performed. Thus, this embodiment of the present invention allows reliable analyzes to be performed with in-vehicle monitoring / analysis / diagnosis systems, which have implementation and cost benefits.

According to an embodiment of the present invention, instead of the suitable size, the substantially stationary motor load L to be maintained and utilized during the analysis is a medium motor load L. This medium motor load L corresponds to about 40% -60% of the maximum maximum motor load. max for said vehicle, and preferably corresponds to about 50% -55% of the maximum possible engine load Lmax. The maximum possible engine load Lmax also depends on the speed of the internal combustion engine 101.

Figure 4 schematically shows an example of when an analysis of a fuel injection system according to the present invention is to be performed. The rough curve shows how much fuel is supplied to the engine by the injection means 121_12N Over time. The middle curve shows what the engine speed looks like over time, which depends, among other things, on the amount of fuel injected and on the braking effect on the vehicle. The bottom curve shows the charge pressure, which is related to the motor load L, Over time.

Charging pressure Or the pressure in the inlet rudder for air to the engine cylinders. It is usually dangerous for the air, with the aid of a compressor, to be forced into the engine during the engine's gas exchange rate in order to achieve a higher engine power.

The Or compressor is often connected to a turbine. When the engine load drops, the oven turbine will wind up, whereby the compressor gradually increases the boost pressure. An increased charging pressure thus corresponds to an increased engine load L. The increased charging pressure also means that there is access to more oxygen in the engine's cylinders, which means that the fuel supply can also be increased to increase torque and power for the engine.

As shown in Figure 4, braking is initiated by activating the front brakes at a brake activation time Tbraxe., Which can essentially coincide with an industry increase time Tfuel increase • This builds up the charge pressure, and above the motor load L, during a first time period 'transients can occur. As is schematically illustrated in the example in Figure 4, for example, oscillations in speed o, and thus also oscillations for the moment M from the motor, occur during the first time period T transient 1 with transients. Since many parameters have a cross-sectional effect on each other and / or between systems in the vehicle, the oscillated speed will affect several systems in the vehicle. Therefore, according to the present invention, no analysis of the systems related to the motor 101 is performed during the first time period.

When the motor load L has been built up by applying the service brakes and the transients / oscillations have subsided, the analysis according to the present invention begins at the analysis start time "analysis zone. As shown in the figure, the charge pressure is maintained and thus the motor load L is essentially stationary / constant for a period of time. When the analysis ends at the analysis end point 'analysis off and / or when the time period' stationary with essentially stationary engine load L ends, the service brakes are deactivated at a brake deactivation time Tbrai „off. After the time period 'stationary dl analysis is performed, there may again be transient processes. the systems during a second time period with transients T transicnt 2r because the charge pressure, and thus the motor load L, drops, which in turn can give transients / oscillations.

Some previously known systems have built up an engine load before the analysis is performed and have since reduced this engine load during the analysis itself. It can be said that the previous kanda lasings have had a corresponding construction phase which the invention during the first time period 'transient dl 21 transients can be dangerous, but then they have not maintained the built-up motor load during the analysis, but have instead let the motor load fall directly from this built-up motor load while the feeds are gars. According to the previous kanda lasings, the second time period with transients Ttransient 2 has followed immediately after the first time period T transient 1AA transients may occur, the viii saga without an intermediate time period 'stationary with essentially stationary motor load L. This causes the feeds in the previous The known readings will be made during a second time period Ttransient 2 where transients occur. The analysis according to the previous known solutions therefore becomes at best unreliable and at most completely incorrect due to the negative impact the transients have on the supplies.

Those skilled in the art will appreciate that a procedure for analyzing a function of at least one system related to an internal combustion engine 101 according to the present invention may additionally be implemented in a computer program, which when executed in a computer causes the computer to perform the procedure. The computer program usually forms part of a computer program product 503, where the computer program product comprises a suitable digital storage medium on which the computer program Or is stored. Said computer lashara medium consists of a readable memory, such as: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc .

Figure 5 schematically shows a control unit 500. The control unit 500 comprises a computing unit 501, which may be constituted by substantially any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or an Application Specific Integrated Circuit (ASIC). The calculating unit 501 is connected to a memory unit 502 arranged in the control unit 500, which provides the calculating unit 501 e.g. the stored program code and / or the stored data calculation unit 501 need to be able to perform calculations. The calculating unit 501 is also arranged to store partial or final results of calculations in the memory unit 502.

Furthermore, the control unit 500 is provided with devices 511, 512, 513, 514 for receiving and transmitting input and output signals, respectively. These input and output signals may contain waveforms, pulses, or other attributes, which of the input signals receiving devices 511, 513 may be detected as information and may be converted into signals which may be processed by the calculating unit 501. These signals are then provided to the calculating unit 501. The devices 512 , 514 for sanding out output signals are arranged to convert bending results from the bending unit 501 into output signals for transmission to other parts of the vehicle control system and / or the component (s) for which the signals are intended, for example to the EBS control unit 155, or any other control unit and / or any other system 120, 130, 160.

Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may be one or more of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Orientated Systems Transport bus), or any other bus configuration; or by a wired connection.

One skilled in the art will appreciate that the above-mentioned computer may be constituted by the storage unit 501 and that the above-mentioned memory may be constituted by the memory unit 502. 23 General control systems in modern vehicles consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECU). : er), or controllers, and various p1 vehicle located components. Such a control system can comprise a large number of control units, and the responsibility for a specific function can be divided into several in one control unit. Vehicles of the type shown thus often significantly comprise their control units in what is shown in Figure 5, which is the choice for the person skilled in the art.

The present invention is in the embodiment shown implemented in the control unit 500. However, the invention may be implemented in whole or in part in one or more other control units already existing in the vehicle or in a control unit dedicated to any of the present invention.

According to one aspect of the present invention, there is provided a system arranged for analysis of a function of at least one system related to an internal combustion engine 101 in a vehicle 100. The system comprises a motor load unit 171, arranged for building a motor load L for the vehicle, where this motor load L has For the analysis of the function suitable size and the motor load unit 171 is arranged to use at least one service brake system in the vehicle when crushing the motor load L. The system also comprises an analysis unit 172, arranged to perform the analysis of the function of the at least one function-analyzed system for a period of time. the built-up motor load L is essentially maintained stationary during the time period Tstationary by continuing to use the At least one four-brake system.

The system according to the present invention can be arranged to carry out all the method embodiments described above, and in the claims, the system for each embodiment receiving the above-described advantages for each embodiment.

Those skilled in the art will also recognize that the above system may be modified according to the various embodiments of the method of the invention.

In addition, the invention relates to a motor vehicle 1, for example a truck or a bus, comprising at least one system for analyzing a function for at least one system related to an internal combustion engine.

The present invention is not limited to the embodiments of the invention described above, but relates to and includes all embodiments within the scope of the appended independent claims.

Claims (20)

A method for analyzing a function of at least one system related to an internal combustion engine (101) in a vehicle (100); characterized by: - building up an engine load L for said vehicle, wherein said engine load L has a size suitable for said analysis and wherein said building up of said engine load L comprises utilizing at least one service brake system (150) in said vehicle (100); and - performing said analysis during a period of time Tstationaryr in which said built-up motor load L is substantially maintained stationary during said period of time Tstationary by continuing to use said at least one feed brake system (150). The method of claim 1, wherein said At least one front braking system (150) applies a braking action to at least one wheel (111, 112, 113, 114) of said vehicle (100). A method according to any one of claims 1-2, wherein said system is a fuel injection system (120) for said internal combustion engine (101). A method according to claim 3, wherein said assay is used to make a diagnosis at least one injection means (121_12N) in said fuel injection system (120). A method according to any one of claims 3-4, wherein said assay is used to ensure that said fuel injection system (120) functions satisfactorily after a replacement of at least one injector (121_12N). A method according to any one of claims 3-4, wherein said assay is used for an adaptation of at least two injection means (121_12N) in said fuel injection system (120). A method according to any one of claims 1-2, wherein said system is an exhaust gas treatment system (130) which purifies exhaust gases from said combustion engine (101). The method of claim 7, wherein said assay is used to create a diagnosis of at least one component of said exhaust gas treatment system (130). A process according to claim 8, wherein said At least one component comprises one or more in the group of: - a reduction catalyst; - a particulate filter; an oxidation catalyst; and - a slip catalyst. A method according to any one of claims 1-2, wherein said system is an overcharger (160) which compresses air entering said combustion engine (101). The method of claim 10, wherein said assay is used to create a diagnosis for said supercharger (160). A method according to any one of claims 1-11, wherein said analysis of said function for at least one system is controlled by at least one analysis control unit (170), which communicates with at least one control unit (140, 155) for said at least one system. A method according to any one of claims 1-12, wherein said analysis of said function comprises at least one system controlled by at least one analysis control unit (170), which communicates with at least one control unit (155) for said at least one service brake system (150). A method according to claim 13, wherein said analysis control unit (170) provides and maintains said substantially stationary built-up motor load L by requesting a braking torque m-breaking of at least one control unit (155) for said at least one service braking system (150). The method of claim 13, wherein said analysis control unit (170) provides and maintains said substantially stationary built-up motor load L by requesting a wheel speed vwheel of said at least one control unit (155) for said at least one front brake system (150). A method according to any one of claims 1-15, wherein said lamp size for said substantially stationary constructed motor load L emits a high motor load L, corresponding to 80-100% of a maximum possible motor load Lmax passes to said vehicle, and dangerously corresponds to 90% -95 % of said maximum possible engine load Lmax. A method according to any one of claims 1-15, wherein said lamp size for said substantially stationary constructed engine load L produces a medium engine load L, corresponding to 40% -60% of a maximum possible engine load Lmax for said vehicle, and preferably corresponding to 50% - 55% of the said maximum possible engine load A method according to any one of claims 16-17, wherein said maximum angular engine load Lmax depends on a speed of said internal combustion engine (101). A method according to any one of claims 1-18, wherein said analysis of at least one system is part of a workshop test. 28 A computer program comprising program code, which when said program code is executed in a computer causes said computer to perform the method according to any one of claims 1 to 19. A computer program product comprising a computer readable medium and a computer program according to claim 20, wherein said computer program is included in said computer readable medium. A system arranged for analyzing a function of at least one system related to a combustion engine (101) in a vehicle (100); characterized by: - an engine load unit (171), arranged to build up an engine load L for said vehicle, where said engine load L has a father said analysis suitable size and where said engine load unit (171) Or arranged to use at least one service braking system (150) in said vehicle (100) in said construction of said motor load L; and - an analysis unit (172), arranged to perform said analysis during a period T stationary while said built-up motor load L is substantially maintained at stations during said period Tstationary by continuing to use said at least one service brake system (150). - ■ • 1440 Crank angle \ 1440 Crank angle OC1. 1. 91.) (1 ° L I. 171. ZLI. I.L1. B01 .---- Zg 1.ozi. _F --- gcl. () LO I. 9i (Z (COI. 1. 171 . 1 .-- r __--- 1791. c91. £ 1.1 .--- / Z '01d 3 / 301. Start 302. Build up engine load I by means of cruise control 303. Perform analysis with maintained engine load