SE1050042A1 - Method and apparatus for preventing fuel accumulation in an exhaust system of a motor vehicle - Google Patents

Abstract

SUMMARY The invention relates to a method for improving the performance of a motor vehicle (100; 110) having an engine (230) and an exhaust system with a particle filter (261). The method comprises the step of determining (s440) whether a predetermined operating condition of said vehicle (100; 110) is met, said operating condition relating to a condition where there is an increased risk of accumulation of fuel in the exhaust system. The method also includes the step of, if said operating condition is met, taking (s460) at least one action to counteract said accumulation of fuel. The invention also relates to a computer program product comprising program code (P) for a computer (200; 210) for implementing a method according to the invention. The invention also relates to a device for improving the performance of a motor vehicle (100; 110) having an engine (230) and an exhaust system with a particulate filter (261) and a motor vehicle equipped with the device. Figure 2 for publication

Description

10 15 20 25 30 If the fuel is injected into an exhaust stream at unfavorable operating points the fuel can hit one and the same point in the exhaust duct, leading to the fuel does not evaporate at the intended place or time and can thus accumulating and flowing inside the exhaust duct.

A possible consequence problem may be that the distribution in the oxidation catalyst and thus the oxidation of the fuel becomes worse than desired, which can result in a lower efficiency and possible fuel grinding, whereby fuel comes through the exhaust system without reacting.

Another possible consequence problem is that the non-evaporated fuel can penetrate through leaky pipes and fittings of the exhaust system, which can also result in a lower efficiency. In addition, this can also lead to one noticeable and unwanted white smoke from the vehicle or industrial engine.

In other words, during operation under certain operating conditions, it has been found to be added fuel does not evaporate and reacts at the rate desired and that said supplied fuel thus accumulates in the exhaust system. This Accumulation of fuel is undesirable and entails a number of different disadvantages. One disadvantage of poorly distributed fuel in the exhaust system is that the finishing system can be damaged or have deteriorated performance e.g. if too much liquid fuel is transported to a downstream device diesel particulate filter or a the aftertreatment system of the vehicle has been damaged, it is costly for one catalyst. In that case driver or owner of the vehicle to be forced to visit a workshop for unplanned repair of the vehicle. The repair is also in itself associated with some costs and potentially large resource consumption.

There is thus a need to rectify the problems that are associated with certain DPF techniques. 10 15 20 25 30 SUMMARY OF THE INVENTION An object of the present invention is to provide a novel and advantageous procedure for improving the performance of a motor vehicle having an engine and an exhaust system with a particulate filter.

Another object of the invention is to provide a new and advantageous device and a new and advantageous computer program to improve performance of a motor vehicle that has an engine and an exhaust system with a particulate filter.

A further object of the invention is to provide a method, a device and a computer program to achieve a more robust exhaust system of a vehicle which results in a reduced maintenance of the same becomes necessary.

A further object of the invention is to provide a method, a device and a computer program to achieve a more cost effective operation of a motor vehicle.

These objects are achieved by a method according to claim 1.

According to one aspect of the invention, there is provided a method of improvement performance of a motor vehicle that has an engine and an exhaust system with a particulate filter, including the steps of: determine whether a predetermined operating condition of said vehicle is fulfilled, wherein said operating permit refers to a permit where there is an increased risk of accumulation of fuel in the exhaust system is present; and if the said operating permit is complied with, take at least one measure to: counteract said accumulation of fuel. 10 15 20 25 30 By predicting that an accumulation of fuel in the exhaust system of the vehicle is about to occur, and to subsequently take active measures to counteract and / or prevent this, an improved performance is achieved in the vehicle. This makes it possible to prevent a driver of the vehicle from having to make unplanned visits to a workshop to perform a costly repair.

An active measure is to control the engine in such a way that an exhaust mass feed thereby changing in a desirable manner, i.e. so that an accumulation of fuel in the exhaust system is counteracted and / or prevented.

An active measure is to influence one in an arbitrarily appropriate way exhaust mass flow in a desirable manner, i.e. so that an accumulation of fuel in the exhaust system is counteracted and / or prevented.

The fuel is the fuel intended to react in an oxidation catalyst of one SCR system of the vehicle. The fuel can e.g. be petrol or diesel.

Said accumulated fuel is the result of an injection of fuel into the exhaust system with less favorable distribution.

An advantage of the present invention is that, where applicable, the active ones the measures can be initiated extremely quickly. The adoption of active measures can be initiated within a time period that is in e.g. of the order of 0.5-10 seconds. The taking of active measures can alternatively be initiated within a time period of the order of 10 seconds to 5 minutes.

The step of determining the operating state may include the step of determining again the vehicle has been operated statically for a certain period of time. By detecting unfavorable operation of the vehicle where the injection of diesel into the exhaust system is directed at one point or a relatively small defined area may be active measures to counteract the accumulation of diesel is deployed at an early stage. The invention takes advantage of the fact that the accumulation of fuel in the exhaust system and 10 15 20 25 30 The operating condition of the vehicle is correlated to define limit values for determination of static or unfavorable operation of the vehicle. determine the operating condition the standard deviation and / or the variance of the engine speed over a period of time The step of including evaluating e.g. and / or to evaluate e.g. the standard deviation and / or the variance for the load of the vehicle for a certain period of time. By evaluating the standard deviation for for example an engine speed can be predicted when a vehicle is in operating points where it is disadvantageous to dispense fuel into an exhaust system.

If the evaluation gives an indication that an unwanted operating condition existing, active measures can be taken and used to change one exhaust flow of the vehicle and / or to change a prevailing temperature in the exhaust system to return to a more favorable operating point of the vehicle.

Alternatively, the dosage of the fuel can be adjusted. It should be noted that the evaluation of e.g. the standard deviation and / or variance of the vehicle load for a certain period of time can be performed in any desired manner to determine whether the predetermined operating permit exists. The predetermined the operating license is an operating license where there is an increased risk of accumulation of fuel in the exhaust system exists.

The innovative procedure makes it possible to improve an efficiency for one regeneration of the particulate filter by detecting and determining one predetermined operating license representing a license including a operating point that is less advantageous from a fuel oxidation perspective by evaluate e.g. the standard deviation of the vehicle's load and / or engine speed.

Such an operating condition may be a static operating condition. A predetermined one operating condition can be an operating condition where the standard deviation and / or is located Another predetermined operating condition may be one the variance of the vehicle's load and / or engine speed within one predetermined interval. operating condition where the standard deviation and / or the variance of the vehicle's load and / or engine speed exceeds predetermined limit values for. Mentioned 10 15 20 25 30 intervals and predetermined limits may be arbitrarily appropriate intervals and predetermined limits.

A predetermined operating condition is an unfavorable operating condition. With unfavorable operating license refers to an operating license where there is an increased risk of accumulation of fuel in the exhaust system exists. This operating permit does not necessarily have to be a stationary operating condition, although the description of the accompanying figures refers to that particular example.

The step of determining the operating state may include the step of determining again the standard deviation and / or variance of the engine speed is less than one predetermined value for a certain period of time. The standard deviation and variance are reliable dimensions that are not computationally heavy for computational units of the vehicle. The engine speed is a parameter that is already detected for today different purposes, so that an additional use of existing information can achieved according to an aspect of the invention. By analyzing variations in engine speed over time can be a possible static operation, or other unfavorable operating condition of the vehicle is determined in a reliable manner.

The step of determining the operating state may include the step of determining again the standard deviation and / or the variance of the vehicle load is less than one predetermined value for a certain period of time. The load of the vehicle is a parameter that today is already calculated for different purposes, why an additional use of existing information can be provided according to one aspect of the invention. With the vehicle's load can e.g. refers to a prevailing torque of an output shaft at the engine of the vehicle. By analyzing variations in the vehicle's load in time, a possible static operation, or other unfavorable operating condition, at the vehicle is reliably determined.

According to a preferred embodiment, the step of determining the operating state may include the step of determining whether the standard deviation and / or the variance of the load of the vehicle and the speed of the engine are less than a predetermined value 10 15 20 25 30 during a certain time. By considering these variables, one can be more reliable procedure for improving the performance of a motor vehicle is provided.

The procedure may further comprise the steps of, before taking the said action: -determine a prevailing temperature at one or fl your arbitrarily selected points between a position for injection of fuel and a position for the particulate filter, and / or - determine a prevailing gas mass flow downstream of the engine and / or - determine a value representing an amount of fuel that has been added the exhaust system for a certain period of time.

By considering more parameters than e.g. engine speed and vehicle load before taking active measures to prevent the accumulation of fuel in The exhaust system allows a safer and more robust procedure to improve performance of the vehicle is achieved.

A selection of active action can be performed on the basis of e.g. a prevailing temperature at the filter, a prevailing gas mass flow downstream of the engine and / or history bet applies to diesel dosing.

A selection of active action can be performed on the basis of e.g. a prevailing temperature at an arbitrarily selected point between a fuel injection position and a position of the particle filter.

The step of taking action may include the step of regulating the supply of fuel into the exhaust system. By reducing the amount of added fuel can improved conditions for evaporating fuel already present in the exhaust system and to evaporate the reduced amount of fuel that should supplied to the exhaust system.

The step of taking action may include the step of varying the temperature of the exhaust gases downstream of the engine. This has the effect of being effective reduce the risk of fuel accumulation in the exhaust system. In particular can 10 15 20 25 30 the step of taking action includes the step of temporarily raising the temperature of the exhaust gases downstream of the engine.

The temperature of the exhaust gases can be varied by controlling the engine on one predetermined way. This is an effective measure to raise relatively quickly the temperature of the exhaust gases.

The procedure is easy to implement in existing motor vehicles. Software for to improve the performance of a motor vehicle having one engine and one exhaust system with a particle filter according to the invention can be installed in a control unit of the vehicle in the manufacture of the same. A buyer of the vehicle may thus be able to choose the function of the procedure as an option.

Alternatively, software including program code can perform the innovative the procedure for improving the performance of a motor vehicle having an engine and an exhaust system with a particle filter is installed in a control unit of the vehicle when upgrading at a service station. In this case, the software can loaded into a memory in the controller. Implementation of the innovative the procedure is thus cost-effective, especially since no further sensors need to be installed in the vehicle. Required hardware is already today the vehicle. thus provided in the Invention thus provides a cost-effective solution to the above problems.

Software that includes program code to improve the performance of a motor vehicles that have an engine and an exhaust system with a particulate filter can easily upgraded or replaced. Furthermore, different parts of the software such as includes program code to improve the performance of a motor vehicle replaced independent of each other. This modular configuration is advantageous from one maintenance perspective.

According to one aspect of the present invention, there is provided an apparatus according to claim 10. 10 15 20 25 30 According to one aspect of the invention, there is provided an apparatus for improving performance of a motor vehicle that has an engine and an exhaust system with a particulate filter. The device comprises means for determining whether a predetermined operating condition of said vehicle is fulfilled, wherein said operating license refers to a license where there is an increased risk of accumulation of fuel in the exhaust system is present; and means for, if said operating condition is fulfilled, take at least one measure to counteract the accumulation of fuel.

The device may further comprise means for determining whether the vehicle has operated statically for a certain period of time.

The device may include means for evaluating the standard deviation and / or the variance of the engine speed over a period of time and / or that evaluate the standard deviation and / or the variance of the vehicle load during a certain time.

The device may further comprise means for determining whether the standard deviation and / or variance of the engine speed is less than one predetermined value for a certain period of time. re-establish the standard deviation and / or the variance of the vehicle load is less than one The device may further comprise means for predetermined value for a certain period of time.

According to a preferred embodiment, the device may comprise means for determine whether the standard deviation and / or the variance of the vehicle's load and the engine speed is less than a predetermined value for a certain period of time.

By considering these variables, a more reliable device for improve the performance of a motor vehicle is achieved. 10 15 20 25 30 10 The device may further comprise means for determining a prevailing one temperature of one or more arbitrarily selected points between a position for injection of fuel and a position for the particulate filter, and / or means for determine a prevailing gas mass flow downstream of the engine and / or means for determine a value representing an amount of fuel that has been added the exhaust system for a certain period of time.

The device may further comprise means for regulating the supply of fuel into the device the exhaust system.

The device may further comprise means for varying the temperature of the exhaust gases downstream of the engine. In particular, said means are arranged to temporarily raise the temperature of the exhaust gases downstream of the engine.

The means for varying the temperature of the exhaust gases downstream of the engine can be arranged to control the engine in a predetermined manner.

The above objects are also achieved with a motor vehicle which includes the special device for improving the performance of a motor vehicle.

The motor vehicle can be a truck, bus or car.

According to one aspect of the invention, there is provided an apparatus for improving performance of a marine engine that has an exhaust system with a particulate filter.

The device includes means for determining whether a predetermined operating condition of said marine engine is met, said operating condition refers to a condition where there is an increased risk of accumulation of fuel in the exhaust system is present; and means for, if said operating condition is fulfilled, take at least one measure to counteract the accumulation of fuel.

According to one aspect of the invention, there is provided an apparatus for improving performance of an industrial engine that has an exhaust system with a 10 15 20 25 30 11 particulate filter. The device comprises means for determining whether a predetermined operating condition of said industrial engine is met, wherein said operating license refers to a license where there is an increased risk of accumulation of fuel in the exhaust system is present; and means for, if said operating permit is fulfilled, take at least one measure to counteract the said accumulation of fuel.

It should be noted that the innovative procedure for improving the performance of a motor vehicle described herein can also be used to on a similar ways to improve the performance of other systems or products, such as e.g. one marine engine or industrial engine. The industrial motor can be used to drive one generator. The marine engine may be mounted on a watercraft, such as e.g. a road ferry.

According to one aspect of the invention, there is provided a computer program for improve the performance of a motor vehicle, wherein said computer program includes program code stored on a computer-readable medium to cause one electronic control unit or another computer connected to the electronic the control unit to perform the steps according to any one of claims 1-9.

According to one aspect of the invention, there is provided a computer software product comprising a program code stored on a computer readable medium for performing the method steps according to any one of claims 1-9, when said computer programs run on an electronic controller or other computer connected to the electronic control unit.

Additional objects, advantages and novel features of the present invention the invention will be apparent to those skilled in the art from the following details, as well via the practice of the invention. While the invention is described below, it will be apparent that the invention is not limited to those specifically described the details. Those who have access to the teachings herein will recognize 10 15 20 12 additional applications, modifications and incorporations within others areas which are within the scope of the invention. SUMMARY DESCRIPTION OF THE FIGURES For a more complete understanding of the present invention and further purposes and benefits thereof, reference is now made to the following detailed description to be read together with the accompanying figures there equally reference numerals refer to equal parts in the various figures, and in which: Figure 1 schematically illustrates a vehicle, according to an embodiment of the invention; Figure 2 schematically illustrates a subsystem of the vehicle shown in Figure 1, according to an embodiment of the invention; Figure 3a schematically illustrates a graph showing how a speed of an engine of the vehicle and the standard deviation thereof depends on the time, according to an example; Figure 3b schematically illustrates a graph showing how a load of the vehicle and the standard deviation thereof depends on the time, according to an example; Figure 4a schematically illustrates a flow chart of a method, according to a embodiment of the invention; Figure 4b schematically illustrates in further detail a flow chart over one method, according to an embodiment of the invention; and Figure 5 schematically illustrates a computer, according to an embodiment of the invention. 10 15 20 25 30 13 DETAILED DESCRIPTION OF THE FIGURES Referring to Figure 1, a side view of a vehicle 100 is shown The exemplary vehicle 100 consists of a tractor 110 and a trailer 112.

The vehicle can be a heavy vehicle, such as a truck or a bus. The vehicle can alternatively be a car.

Here, the term "link" refers to a communication link that may be one physical wire, such as an opto-electronic communications wire, or a non-physical wiring, such as a wireless connection, such as a radio or microwave link k.

Herein, the term "static operation" of the vehicle 100 refers to a condition there the vehicle is operated in such a way that the supply of fuel to the exhaust system can entail an increased risk of accumulation of non-evaporated fuel. Accumulation of fuel can occur when the vehicle is driving in extremely static injection points, which usually happens when the vehicle is driving statically. Static operation of the vehicle can include that variations in engine speed are small over time. Static operation of the vehicle may involve small variations in the load of the vehicle over time.

Here, the term "load" refers to a torque of one starting from the engine shaft in the driveline. The term "load" may alternatively refer to a torque of a shaft emanating from the engine in the driveline relative to a maximum available torque. One skilled in the art will recognize that various definitions of the term "load" may be used within the scope of the present invention.

Referring to Figure 2, a subsystem 299 of the vehicle is shown schematically 100. The subsystem 299 is arranged in the tractor 110. The subsystem 299 consists of a motor 230 arranged to drive the vehicle 100. The motor 230 is one internal combustion engine. The engine 230 can be a diesel engine with an arbitrary number of cylinders, such as e.g. 4, 5 or 6 cylinders. 10 15 20 25 30 14 The exhaust gases generated by the engine 230 during operation of the vehicle 100 are arranged to be led in a first tube 235 to a particle filter 261. The filter 261 is according to this exemplary embodiment a so-called DPF. The filter 261 may have a catalytic coating. The filter 261 is connected to a second tube 265 which is arranged to discharge the exhaust gases from the vehicle 100 to an environment thereof. It appears for one skilled in the art that subsystem 299 may include additional components, such as e.g. an SCR catalyst or other catalyst to reduce emissions from the vehicle 100. These other components have been omitted for to clarify the invention.

A first sensor 245 is arranged upstream of the filter 261 at the first tube 235. The first sensor 245 is arranged to measure a gas mass flow therein the first tube 235. The first sensor 245 is arranged continuously detecting values representing gas mass flow in the first tube 235. The the first sensor 245 is arranged to detect gas mass flow in it in real time the first tube 235. The first sensor 245 is arranged for communication with an emission controller 220 via a link 246. The first sensor 245 is arranged to continuously send signals including information about a the first tube 235 to The emission control unit 220 is arranged to receive the signals transmitted from gas mass flow in the emission control unit 220. the first sensor 245.

A second sensor 275 is provided at the filter 261. The second sensor 275 is arranged to measure a prevailing temperature of the filter 261. The second sensor 275 is arranged to continuously detect a prevailing temperature of the filter 261. The second sensor 275 is arranged to detect a prevailing one in real time temperature of the filter 261. According to a preferred embodiment, the other is the sensor 275 arranged to determine a prevailing temperature of a arbitrarily selected point between a fuel injection mode and a mode for the particle filter 261. The second sensor 275 is arranged for communication with the emission controller 220 via a link 276. The second sensor 275 is 10 15 20 25 30 15 arranged to continuously send signals including information about a prevailing temperature of the filter 261 to the emission controller 220. The other the sensor 275 is alternatively arranged to continuously send signals including information about a prevailing temperature of an arbitrarily selected one point between a position for injecting fuel and a position for the particulate filter 261 to the emission control unit 220. The emission control unit 220 is arranged to receiving the signals transmitted from the second sensor 275.

The emission control unit 220 is arranged for communication with a fuel injector 255 via a link 256. Fuel injector 255 is present arranged at the first tube 235. The emission control unit 220 is arranged to control the fuel injector 255 by means of control signals transmitted via the link 256.

The fuel injector 255 is arranged to inject fuel into the first tube 235 i depending on the received control signals.

According to this embodiment, the fuel injector 255 is arranged to inject diesel in the first tube 235. A container, such as e.g. a fuel tank (no shown) is arranged to hold said diesel. The container is flow-connected to the injector 255 via a passage arranged to lead said diesel to the injector 255 to be injected into the first tube 235.

By injecting diesel, or other suitable fuel, a regeneration of the filter 261.

During static operation, fuel supplied to the first pipe 235 may accumulate, instead to evaporate and be effectively burned, thus forming an unwanted volume of substantially liquid fuel in the first tube 235. During prolonged static operation of the vehicle, this volume can be built up in such a way that the vehicle's performance deteriorates. The present invention aims to prevent this accumulation of liquid fuel. 10 15 20 25 30 16 It will be apparent to one skilled in the art that the first sensor 245, the second sensor 270 and the fuel injector 255 may be of a suitable type and that they may be configured appropriately in subsystem 299.

According to one embodiment, a motor control unit 200 is arranged for communication with the emission control unit 220 via a link 226. The motor control unit 200 is also referred to as a first control unit 200. The first control unit 200 is arranged to control the emission control unit 220 by continuously transmitting control signals to the same. In the first control unit 220 there is one emission model stored in a memory. The first control unit 200 can be included using the stored emission model to estimate a prevailing gas mass flow in the first pipe 235. The first control unit 200 can with using the stored emission model also estimate a prevailing temperature in the filter 261. According to one embodiment of the invention, the first the control unit 200 arranged to estimate a prevailing gas mass flow in the first the pipe 235 which should be present at a given operating case of the vehicle 100. On a similarly, the first control unit 200 is arranged to estimate one prevailing temperature of the filter 261 which should be present at a given operating case in the vehicle 100.

The first control unit 200 is arranged to calculate one in a conventional manner prevailing load on the vehicle, such as e.g. a prevailing torque in a output shaft of the engine 230.

According to one example, the first controller 200 may be a Master and the emission controller can be a Slave. The first control unit 200 is arranged to control injection of fuel into the first tube 235 according to stored drivers.

The first control unit 200 is arranged to control the temperature of the exhaust gases downstream of the engine by e.g. change the injection angle of at least one cylinder of the engine. 10 15 20 25 30 17 The first control unit 200 is arranged to control the motor 230 on one predetermined way to regulate the temperature of the exhaust gases downstream the motor 230. The first control unit 200 is arranged to control regeneration of the particulate filter 261 of the exhaust system when required.

A second control unit 210 is provided for communication with the first the control unit 200 via a link 216. The second control unit 210 may be detachably connected to the first control unit 200. The second control unit 210 may be an external control unit for the vehicle 100. The second control unit 210 may be arranged to perform the innovative process steps according to the invention. The second control unit 210 can be used to overload software for the first control unit 200, in particular software for performing the innovative procedure. The second control unit 210 may alternatively be arranged for communication with the first control unit 200 via an internal network in the vehicle. The second control unit 210 may be arranged to perform substantially the same functions as the first control unit 200, such as e.g. to determine whether a predetermined operating condition of said vehicle is fulfilled, wherein said operating permit refers to a permit where there is an increased risk of accumulation of fuel in the exhaust system is present and, if mentioned operating permit is fulfilled, take at least one measure to counteract the said accumulation of fuel.

According to the embodiment described with reference to Figure 2, the first the sensor 245, the other sensor 275 and the injector 255 are signal connected to emission controller 220. It should be noted that other configurations may realized. For example. the first sensor 245, the second sensor 275 and the injector 255 may be signal connected to the first control unit 200 and / or the second controller 210. One skilled in the art will recognize that various variants are possible to realize. Parts of the innovative process can be stored software is executed in the first controller 200, the second controller 210 and the emission controller 220, or a combination thereof. It should be pointed out 10 15 20 25 30 18 that the first control unit 200, the second control unit 210 and the emission controller 220 may be physically separated, alternatively partially or fully integrated.

Figure 3a schematically illustrates a graph showing how a speed rpm of a engine of the vehicle and the standard deviation said thereof depends on the time, according to one example.

The engine speed rpm is described by graph a. It is shown according to this example that the vehicle 100 is driven non-statically until a time T1a. After the time T1a, the vehicle 100 is driven in a static manner. If the vehicle 100 is driven on this static methods increase the risk of accumulation of fuel in the exhaust system of the vehicle.

The standard deviation said of the speed rpm is also illustrated in Figure 3a. Of natural reasons reduce the standard deviation said to a minimum (0) when the vehicle is operated at a substantially constant speed, such as after the time T1a.

In case the standard deviation said of the speed rpm is less than a predetermined one level L1a for a certain time ATa it can be determined that an operating condition of said vehicle is fulfilled, wherein said operating condition refers to a condition where there is an increased risk of accumulation of fuel in the exhaust system. With others words, it is hereby established that the vehicle has been driven in a static manner during a some critical time, whereby an increased risk of accumulation of fuel in the exhaust system exists. The time ATa is an arbitrary predetermined time.

Figure 3b schematically illustrates a graph showing how a load Tq of the vehicle and the standard deviation sb thereof depends on the time, according to an example. According to in this example, the load Tq is the torque of one exiting the motor shoulder. 10 15 20 25 30 19 The load Tq is described by graph b. It appears from this example that the vehicle 100 is driven non-statically until a time T1b. After time T1b is operated vehicle 100 in a static manner. If the vehicle 100 is driven in this static manner increases the risk of accumulation of fuel in the vehicle's exhaust system.

The standard deviation sb of the load Tq is also illustrated in Figure 3b. Of natural reasons, the standard deviation sb decreases to a minimum (0) when the vehicle is driven with a substantially constant load, such as after time T1b.

In case the standard deviation sb of the load Tq is less than a predetermined one level L1b for a certain time ATb, it can be determined that an operating condition of said vehicle is fulfilled, wherein said operating condition refers to a condition where there is an increased risk of accumulation of fuel in the exhaust system. With others words, it is hereby established that the vehicle has been driven in a static manner during a some critical time, the exhaust system exists. The time ATb is an arbitrary predetermined time. whereby an increased risk of accumulation of fuel in With reference to Figure 3a and Figure 3b, two different ways of determine whether a static operating condition of the vehicle has been present during a predetermined time, the exhaust system of the vehicle is present. whereby an increased risk of accumulation of fuel in One skilled in the art will recognize that there are a number of different ways to determine whether one vehicles are operated statically for a predetermined period of time. For example. would a procedure there the variance of the vehicle's speed and load can be used in a similar way way. Alternatively, a static operating condition of the vehicle would can be determined by analyzing a first or second derivative characteristics over time for engine speed and / or load.

It should be noted that parameters other than the engine speed and load can be used to determine whether a static operating condition of the vehicle 10 15 20 25 30 20 exists. For example. the exhaust gas mass flow parameter could be used to determine whether there is a static operating condition of the vehicle.

Here, the parameters engine speed and vehicle load have been selected to be clear exemplify a couple of embodiments of the present invention. On a similarly have the use of the standard deviation of these parameters selected to exemplify some embodiments of the present invention.

Figure 4a schematically illustrates a flow chart of a method for improve the performance of a motor vehicle that has one engine and one exhaust system with a particle filter, according to an embodiment of the invention.

The method comprises a first method step s401. Includes s401 included the steps to: determine whether a predetermined operating condition of said vehicle is fulfilled, wherein said operating permit refers to a permit where there is an increased risk of accumulation of fuel in the exhaust system is present; and if the said operating permit is complied with, take at least one measure to: counteract said accumulation of fuel.

Figure 4b schematically illustrates in further detail a flow chart over one procedure for improving the performance of a motor vehicle having an engine and an exhaust system with a particulate filter, according to an embodiment of the invention.

The method includes a first method step s410. Procedure step s410 involves the step of determining an arbitrary number of parameter values. According to this example detects a number of values for the prevailing speed rpm of the engine 230 of the vehicle 100. Alternatively, e.g. a number of values for prevailing load Tq of the vehicle is calculated in a conventional way. After the process step s410 performs a subsequent process step s420. 10 15 20 25 30 21 The process step s420 includes the step of processing the determined ones the parameter values. According to this example, the standard deviation is calculated for the detected values of current rpm of the engine 230. According to that alternative example, the standard deviation sb is calculated for the calculated ones the values for the prevailing load Tq of the vehicle. After the procedure step s420 is performed a subsequent procedure step s430.

The method step s430 includes the step of determining whether it calculated standard deviation said is less than a predetermined threshold value L18 ATa. the process step s430 the step of determining whether the calculated a predetermined threshold value L1b regarding a predetermined time Alternatively includes the standard deviation sb is less than regarding a predetermined time ATb.

It should be noted that the step of determining whether the standard deviation said falls below the predetermined threshold value L1a with respect to the predetermined one the time ATa and the step of determining whether it is calculated the standard deviation sb is less than the predetermined threshold value L1b with respect to the predetermined time ATb is only an example. to determine whether the standard deviation said exceeds a predetermined threshold value for a Step s430 may alternatively include step predetermined time and / or the step of determining whether it is calculated the standard deviation sb exceeds a predetermined threshold value for a predetermined time.

Step s430 may alternatively include the more general step of determining operating state by evaluating whether at least one parameter meets a condition. This may include evaluating the standard deviation and / or the variance of the engine speed over a period of time and / or that evaluate the standard deviation and / or the variance of the vehicle load during a certain time. 10 15 20 25 30 22 Said conditions may constitute a case where the standard deviation is less than that predetermined threshold value L1a with respect to the predetermined time ATa and / or where the calculated standard deviation sb is less than that predetermined threshold value L1 b with respect to the predetermined time ATb Said condition may constitute a case where the standard deviation said exceeds one predetermined threshold value for a predetermined time and / or where it calculated standard deviation sb exceeds a predetermined threshold value regarding a predetermined time.

If said condition is met, a subsequent procedure step s440 is performed. If said condition is not met, the step step s410 is performed again.

The method step s440 includes the step of determining that a predetermined operating license is available. The operating permit refers to a condition where there is an increased risk for the accumulation of fuel in the exhaust system. After the procedure step s440, a subsequent procedure step s450 is performed.

The step step s450 includes the step of checking whether it is applicable to take measures to counteract the said accumulation of fuel. This may include the step of determining a prevailing temperature of the particulate filter 261 and comparing this temperature with a reference temperature to determine if it is appropriate to take the said measures. This may include the step to determine a prevailing temperature at an arbitrarily selected point between a position for fuel injection and a position for the particulate filter 261 and compare this temperature with a reference temperature to determine if it is applicable to take the said measures. Alternatively, it may include the step to determine a prevailing gas mass flow downstream of the engine 230 and compare this value with a reference mass flow to determine if it is applicable to take the said measures. Alternatively, it may include the step of determining one value representing an amount of fuel that has been supplied to the exhaust system 10 15 20 25 30 23 for a certain period of time to determine whether it is appropriate to take the said measures. After the process step s440, a subsequent process step is performed s460.

The process step s460 includes the step of, if applicable, on the basis of as a result of previous procedural steps, take active steps to: counteract said accumulation of fuel. After the procedure step s460 the procedure is terminated.

Referring to Figure 5, a diagram of an embodiment of one is shown device 500. The control units 200 and 210 described with reference to Figure 2 may in one embodiment comprise the device 500. The device 500 includes a non-volatile memory 520, a data processing unit 510, and a read / write memory 550. The non-volatile memory 520 has a first memory portion 530 wherein a computer program, such as an operating system, is stored for control the function of the device 200. Furthermore, the device 500 comprises a bus controller, a serial communication port, an I / O device, an A / D converter, a time and date input and transfer unit, an event counter and an interrupt controller (not shown). The non-volatile memory 520 also has a second memory part 540.

A computer program P is provided which includes routines for improvement performance of a motor vehicle 100 having an engine of 230 and one exhaust system with a particulate filter 261, according to the innovative procedure.

Program P includes routines for determining whether a predetermined operating condition of said vehicle is fulfilled, wherein said operating condition relates to a state where there is an increased risk of accumulation of fuel in the exhaust system exists. The program P includes routines for, if said operating condition is fulfilled, take at least one measure to counteract the accumulation of fuel, in accordance with the innovative procedure. The program P can be stored in an executable manner or compressed in a memory 560 and / or in a read / write memory 550. When it is described that the data processing unit 510 10 15 20 25 30 24 performs a certain function, it should be understood that the data processing unit 510 performs one certain part of the program which is stored in memory 560, or a certain part of the program stored in the Read / Write memory 550.

The data processing device 510 can communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is for communication with the data processing unit 510 via a data bus 512. The separate memory 560 is intended to communicate with the data processing unit 510 via a data bus 511. the data processing unit 510 via a data bus 514. To the data port 599 can for example links 206, 216, 226, 246, 256 and 276 are connected (see Figure 2).

The read / write memory 550 is arranged to communicate with When data is received on data port 599, it is temporarily stored in the other 540. When the data processing unit 510 is prepared to perform code execution on the memory part received input data has been temporarily stored, is a manner described above. According to one embodiment, signals include received on the data port 599 information of a prevailing speed of the engine 230 of the vehicle 100. According to one embodiment, signals received at the data port include 599 information about a current load on the vehicle. The received signals on the data port 599 can be used by the device 500 to determine if the vehicle 100 is operated in a manner which increases the risk of accumulation of fuel in the exhaust system. The device 500 is arranged to, if said condition exist, take active measures to counteract the said accumulation of fuel in the exhaust system. Parts of the methods described herein can be performed by the device 500 by means of the running data processing unit 510 the program stored in the memory 560 or the read / write memory 550. When the device 500 runs the program, the procedures described herein are executed.

The foregoing description of the preferred embodiments of the present invention has been provided for the purpose of illustrating and describing the invention. It is not intended to be exhaustive or restrictive the invention to the described variants. Obviously many will come 25 modifications and variations to be apparent to those skilled in the art. The embodiments was selected and described to best explain the principles of the invention and its practical applications, thus enabling professionals to understand the invention for different embodiments and with the different modifications as are suitable for the intended use.

Claims (22)

10 15 20 25 30 26 PATENT REQUIREMENTS A method of improving the performance of a motor vehicle (100; 110) having an engine (230) and an exhaust system with a particulate filter (261), the method being characterized by the steps of: - determining (s440) whether a predetermined operating condition of said vehicle (100; 110) is met, said operating condition relating to a condition where there is an increased risk of accumulation of fuel in the exhaust system; and - if said operating permit is fulfilled, take (s460) at least one measure to counteract said accumulation of fuel. The method of claim 1, wherein the step of determining the operating state comprises determining (s430) whether the vehicle (100; 110) has been statically driven for a certain time (ATa; ATb). A method according to claim 1 or 2, wherein the step of determining the operating condition comprises evaluating the standard deviation (sa) and / or the variance (sza) of the engine speed (rpm) over a certain time (ATa) and / or evaluating the standard deviation (sb). and / or the variance (szb) of the vehicle load (Tq) over a given period of time (ATb). A method according to any one of claims 1-3, wherein the step of determining the operating state (s430) the variance (sza) of the engine speed (rpm) is less than a predetermined value (L1a) for a certain time (ATa). involves determining whether the standard deviation (sa) and / or A method according to any one of the preceding claims, wherein the step of determining the operating condition comprises the step of determining (s430) whether the standard deviation (sb) and / or the variance (szb) of the vehicle load (Tq) is less than a predetermined value (L1b) for a certain time (ATb). 10 15 20 25 30 27 A method according to any one of the preceding claims, further comprising the steps of, before taking said action: - determining (450) a prevailing temperature at an arbitrarily selected point between a position for injecting fuel and a position for the particulate filter (261), and / or - determining (s450) a prevailing gas mass flow downstream of the engine (230); and / or - determining (s450) a value representing an amount of fuel that has been supplied to the exhaust system for a certain period of time. A method according to any one of the preceding claims, wherein the step of taking a measure comprises the step of: - regulating the supply of fuel into the exhaust system. A method according to any one of the preceding claims, wherein the step of taking action comprises the step of: - varying the temperature of the exhaust gases downstream of the engine (230). The method of claim 8, wherein the temperature of the exhaust gases is varied by controlling the engine (230) in a predetermined manner. Device for improving the performance of a motor vehicle (100; 110) having an engine (230) and an exhaust system with a particulate filter (261), characterized by: - means (200; 210; 220; 500) for determining whether a predetermined operating condition of said vehicle (100; 110) is fulfilled, said operating condition relating to a condition where there is an increased risk of accumulation of fuel in the exhaust system; and - means (200; 210; 220; 500) for, if the said operating permit is fulfilled, taking at least one measure to counteract the accumulation of fuel. The apparatus of claim 10, further comprising means for determining whether the vehicle (100; 110) has been statically driven for a period of time (ATa; ATb). 10 15 20 25 30 28 Device according to claim 10 or 11, comprising means (200; 210; 220; 500) for evaluating the standard deviation (sa) and / or the variance (sza) of the engine speed (rpm) for a certain time (ATa) and / or to evaluate the standard deviation (sb) and / or the variance (szb) of the vehicle load (Tq) during a certain time (ATb). Device according to any one of claims 10-12, further comprising: - means (200; 210; 500) for determining whether the standard deviation (sa) and / or the variance (sza) of the engine speed (rpm) is less than a predetermined value (L1a ) for a certain period of time (ATa). Device according to any one of claims 10-13, further comprising: - means (200; 210; 500) for determining whether the standard deviation (sb) and / or the variance (szb) of the vehicle load (Tq) is less than a predetermined value (L1b ) for a certain period of time (ATb). An apparatus according to any one of claims 10 to 14, further comprising: - means (270, 220) for determining a prevailing temperature of an arbitrarily selected point between a position for injecting fuel and a position for the particulate filter (261), and / or - means (245; 220) for determining a prevailing gas mass flow downstream of the engine (230): and / or means (200; 210; 220) for determining a value representing an amount of fuel which has been supplied to the exhaust system for a certain period of time. An apparatus according to any one of claims 10-15, further comprising: means (200; 210; 220; 255) for regulating the supply of fuel into the exhaust system. The apparatus of any of claims 10-16, further comprising: means (200; 210; 220) for varying the temperature of the exhaust gases downstream of the engine (230). Device according to claim 17, wherein means (200; 210; 220) for varying the temperature of the exhaust gases downstream of the engine (230) are arranged to: - control the engine (230) in a predetermined manner. A motor vehicle (100; 110) comprising a device according to any one of claims 10-16. The motor vehicle (100; 110) according to claim 19, wherein the motor vehicle is something of a truck, bus or passenger car. A computer program (P) for improving the performance of a motor vehicle (100; 110) having an engine (230) and an exhaust system with a particulate filter (261), said computer program (P) comprising program code stored on a computer, readable medium for causing an electronic control unit (200; 500) or another computer (210; 220; 500) connected to the electronic control unit (200; 500) to perform the steps according to any one of claims 1-9. A computer program product comprising a program code stored on a computer readable medium for performing the method steps of any of claims 1-9, when said computer program is run on an electronic control unit (200; 500) or another computer (210; 220; 500) connected to the electronic control unit (200; 500).