• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a method of diagnosing a fuel system at a vehicle (100), said vehicle (100) comprising an internal combustion engine. (101) and at least one fuel tank (215A, 215B; 209) for receiving fuel, said fuel system comprising a first fuel pump (212A; 210A) for use in transferring fuel between said first fuel tank (215A, 215B; 209) and said an internal combustion engine (101), a second fuel pump (212B; 210B) arranged to operate in parallel with said first fuel pump (212A; 210A) in transferring fuel between said first fuel tank (215A, 215B; 209) and said internal combustion engine (101), and a in said fuel system upstream of said first and second fuel pump, respectively, arranged pressure sensor means (228, 229). The method comprises: - filtering said signal from said first pressure sensor means (228, 229) by using a first filter, and - based on said filtered signal determining a presence of a first fuel soldering error in said fuel system. 3
    公开号:SE1550926A1
    申请号:SE1550926
    申请日:2015-07-01
    公开日:2017-01-02
    发明作者:Stenlåås Ola；Jacobsson Susanna；Jorques Moreno Carlos；Ellnefjärd Andre
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    FIELD OF THE INVENTION The present invention relates to a method for diagnosing a fuel system according to the preamble of claim 1. The invention also relates to a system and a vehicle, as well as to a computer according to the invention. Background The present invention relates to fuel systems for wide vehicles, and in particular to heavy vehicles such as trucks, buses and work machines. These types of vehicles are often relatively heavy, and also often travel long distances. Taken together, this entails a requirement that the vehicles be equipped with relatively large fuel tanks. For example. such vehicle goods can be provided with a fuel tank accommodating in the order of 500-100 liters, as this volume can also be distributed over two fuel tanks arranged at the vehicle.
    The fuel tanks thus consist of relatively large volumes, which means that when the fuel level decreases, the remaining fuel will be moved around in the fuel tank depending on the movements of the vehicle. Fuel transfer from the fuel tank to the vehicle's internal combustion engine is usually performed by using a sinker in the fuel tank with an inlet through which the fuel is sucked up by means of a pump. In order for fuel to be sucked by means of the said pump, however, it is required that the inlet of the luminaire is surrounded by fuel and not by air.
    Regarding fuel systems in vehicles, a fuel pump is often used arranged in connection with the internal combustion engine for 10 suction of fuel, where the fuel pump is mechanically coupled to the internal combustion engine and is driven by the internal combustion engine drive shaft. This solution means that the fuel pump must be able to pump a relatively large amount of fuel already at position rotation speed, ie. lower rotational speed than the idle speed of the internal combustion engine, in order to be able to pump a sufficient amount of fuel to the internal combustion engine when the starting engine operates so that the internal combustion engine can start at all. This in turn means that the fuel pump during operation will be oversized with associated losses as a result.
    Furthermore, a fuel pump driven by the internal combustion engine output shaft, if it starts to suck air, e.g. due to low fuel level, start cavitating with the result that the pump does not start sucking fuel without first stopping, which means that the vehicle must be stopped before the fuel supply can be resumed.
    The above disadvantages can be reduced by using electrically powered, ie. A fuel pump driven by an electric motor, wherein the speed of the fuel pump can be regulated independently of the speed of the output shaft of the internal combustion engine. Furthermore, in such systems the operational reliability can be increased by using parallel operating fuel pumps. Summary of the invention It is an object of the present invention. a fuel system for vehicles. This object is achieved by a method according to claim 1.
    The present invention relates to a method for diagnosing a fuel system in a vehicle, said vehicle comprising an internal combustion engine and at least one fuel tank for receiving fuel, said 10 fuel system comprising a first fuel pump for use in transferring fuel between said fuel and said first fuel. second fuel pump arranged to operate in parallel with said first fuel pump in transferring fuel between said first fuel tank and said internal combustion engine, and a pressure sensor means upstream of said first and second fuel pump upstream in said fuel system. The method comprises: - filtering said signal from said first pressure sensor means by using a first filter, and - based on said filtered signal determining a presence of a first fuel flow error in said fuel system.
    The use of electrically driven fuel pumps can alleviate problems that can arise when using fuel pumps driven by the output shaft of the internal combustion engine. Furthermore, especially with regard to heavy vehicles, operational safety is an important parameter, and as will be appreciated, a functioning fuel supply is also a very important parameter of operational safety. For this reason, the present invention applies a system in which two parallel-operating and electrically driven fuel pumps are used for the transfer of fuel from the vehicle's fuel tank to the vehicle's internal combustion engine, for example to a fuel supply system arranged at said internal combustion engine, such as e.g. a fuel injection system.
    The fuel pumps can be arranged for individual control, e.g. by individual control of a respective associate sub-motor. By using parallel operating fuel pumps, e.g. a redundancy, which enables fuel to be transferred even when one fuel pump is malfunctioning. With regard to fuel systems in general, operational reliability is very important, and thus it is also desirable to be able to identify faulty function in the fuel system at an early stage as possible, and the present invention also provides a method for diagnosing a system with pearl-fueled fuel. Furthermore, if an error occurs, it is desirable to be able to identify the fault claimant other than for comprehensive troubleshooting. For example. known components in a fuel metering system are difficult to access, e.g. Basically, components such as fuel pumps are located inside a fuel tank. In particular, the present invention provides a method for enabling the identification of the occurrence of, and / or cause of, faults in the fuel flow.
    According to the invention, this is provided in particular through utilization of information from upstream of the fuel pump and other pressure sensors, such as one or more pressure sensors. The signal from the pressure sensor means through the filter race also utilized a filter, in which case the pressure signal station part, the zero frequency component in the pressure signal, is suppressed, filtered out, to the extent that the noise signal becomes dominant. In addition to the zero frequency component, very low frequency components can be suppressed, filtered out, such as e.g. frequencies in the range O-0.5 Hz or O-0.2 Hz.
    By suppressing the zero-frequency component, the filter-ready pressure signal will essentially consist of the measuring noise, which is known to be emitted and used to detect the occurrence of errors in the fuel flow. For example. known noise signal amplitude is compared with an amplitude level at which errors are present, whereby e.g. unexpectedly high amplitudes are also used as an indication of the presence of faults. According to one embodiment, the amplitude of that filtering signal can be compared to any applicable amplitude at which errors are present for a plurality of consecutive times during a first time period of said filtering signal, a signal indicating a fault in said fuel system may be generated when the amplitude of said filtered filter exceeds said filter. amplitude at least a first plurality of times during said first time period.
    The method may also be arranged to compare the amplitude of the filtered signal with any applicable amplitude during a first time period of the filtered signal, and when the amplitude of the filtered signal exceeds said applicable amplitude at least for a certain time of said first time period a signal indicating a fuel flow fault system may occur. By requiring that the noise amplitude repeatedly exceeds an amplitude level, the risk of erroneous error detection can be reduced.
    According to an embodiment of the invention, said filtered signal is transformed into a frequency plane, e.g. utilization of EFT (Fast Fourier Transform) or other applicable transformer, as well as other applicable Fourier transform, wherein the occurrence of fuel flow errors in said fuel system is determined at least partly based on a frequency analysis mentioned transformed signal. For example. For example, the presence of a certain frequency in the transformed signal can be used as an indication of the presence of a fault.
    According to an embodiment of the invention, when said frequency analysis indicates the presence of an error, a second, different frequency analysis from different, analysis can be performed for the purpose of confirming the error, whereby errors can be considered correct only if another analysis also indicates so. Alternatively, said second analysis can be used to identify the error. According to one embodiment, a second analysis is used where the said fuel pumps are controlled to a first speed, such as e.g. a maximum speed or other applicable speed. The resulting pressure determined by the average pressure sensor can then be compared with a first pressure, whereby the presence of said first fuel flow error can be considered to exist when the signal generated by said pressure sensor deviates from said first pressure by a first pressure difference.
    According to one embodiment, this second method is used to detect the type of error. If the pressure determined by means of the pressure sensor deviates from said first pressure by more than one first pressure difference, e.g. the fault is identified as a leak on the suction side of the fuel pumps, while, conversely, the fault can be identified as a leak on the pressure side of the fuel pumps in the event that the pressure difference does not exceed any applicable value.
    The invention is applicable to different types of fuel systems, and according to an embodiment, an intermediate combustion engine and said first at least one main tank, arranged transfer tank, also called "catch-tank" or "tech-tank", hereinafter referred to as transfer tank, are applied, the method comprising supplying fuel to said transfer tank from said first main tank before transfer takes place to said fuel supply system from said transfer tank, and wherein said transfer tank preferably constitutes a smaller tank compared with said first fuel tank. Transfer tank volume edge.ex. constitute a volume in the range 1-10%, or 1-5%, of said total volume of at least one main tank.
    The transfer tank is thus significantly smaller than the main tank, which means that it is also less sensitive to the movements of the fuel in the tank due to movements and road inclines. When the transfer tank is filled, it therefore functions as a buffer at times when fuel cannot be sucked out of the main tank, e.g. due to low fuel level in combination with sloping surfaces, whereby fuel can be transferred to the fuel supply system from the transfer tank even when the fuel mentioned first main tank is not available, and whereby the transfer tank eats can be filled when conditions allow this and the main tank fuel is available. Such a solution thus allows an even larger proportion of the main tank fuel to be used before refueling is required.
    According to one embodiment, said first and second fuel pump, respectively, are used for transferring fuel to said transfer tank from said at least one main tank on the path of the fuel opposite said internal combustion engine. According to another embodiment, said first and second fuel pump, respectively, are used for pre-transfer of fuel from said transfer tank to said fuel supply system. According to one embodiment, a first pair of parallel operating fuel pumps is used to transfer fuel to said transfer tank from said at least one main tank, and a second pair of parallel operating fuel pumps for transferring fuel from said transfer tank to said fuel supply system, the present invention being applicable to either on separate occasions for each couple.
    Additional features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments and the accompanying drawings. Brief Description of the Drawings Fig. 1A schematically shows a vehicle in which the present invention may be used to advantage.
    Fig. 1B shows a control unit in a vehicle control system.
    Fig. 2 schematically shows a fuel system to which the present invention can be applied.
    Fig. 3 schematically shows an exemplary method according to one embodiment of the present invention.
    Fig. 4 shows an example of a filtered pressure signal.
    Figs. 5A-B show an example of a step response test at or without the presence of a leak.
    Figs. 6A-D show an example of filtering a pressure signal and transforming into a frequency plane of said filtered pressure signal. Detailed Description of Preferred Embodiments Fig. 1A schematically shows a driveline in a vehicle 100 according to an embodiment of the present invention. The vehicle 100 shown schematically in Fig. 1 comprises a driveline with a single-combustion engine 101, which is connected in a conventional manner, via a shaft extending via the internal combustion engine 101, usually via a flywheel 102, to a gearbox 103 via a single clutch 106. The internal combustion engine 101 is controlled by the vehicle a motor control unit 115. Similarly, in the present example, clutch 106 and gearbox, respectively, are controlled by a control unit 116.
    Furthermore, a shaft 107 extending from the gearbox 103 drives drive wheels 113, 114 via an end gear 108, such as e.g. unusual differential, and drive shafts 104, 105 connected to said final gear 108. Fig. 1A thus shows a driveline of a specific type, but the invention is applicable to all types of drivelines, and also to all types of vehicles, as long as they are driven by an internal combustion engine.
    The vehicle shown also comprises a fuel system, in which fig. 1A, two main fuel tanks 215A, 215B are shown from which fuel is supplied to the internal combustion engine by supply to a fuel metering system connected to the internal combustion engine 101, in the present example an injection system 204, in the inlet tank 209. The fuel system is also controlled in accordance with the control system. described below.
    According to the above, the present invention relates to the diagnosis of the fuel system. The method according to the invention can be carried out by a control unit present in any vehicle applicable to the vehicle's control system, and may, for example, be controlled by a control unit 230 or evenly applicable to the vehicle's control unit, such as the engine control unit 115. control unit in the control system of the vehicle. The invention can also be implemented in a control unit dedicated to the present invention.
    In general, such control systems consist of a communication bus system consisting of one or more communication buses for a single-pair electronic control units (ECUs), or controllers, and different components of the vehicle 100. Such a control system thus feels like it has a large number of control units, and the difficulty for a specific function can be divided into piles rather than a control unit. For the sake of simplicity, Fig. 1A only shows a very limited number of control units.
    The function of the control unit 230 (or the control unit (s) to which the present invention is implemented) according to the present invention is known e.g. will also depend on signals from different sensors, such as e.g. signals from pressure sensors 228, 229 as shown below. Furthermore, the function according to the invention may depend on signals from the fuel pump (s) which provide for the transfer of fuel from the fuel tank injection system as below, when the signals may include information regarding e.g. speed, torque delivered, fuel flow, and / or power consumption. The control can also depend on signals from one or more other control units.
    Furthermore, the control is often performed by programmed instructions. These programmed instructions typically consist of a computer program, which when executed in the control unit causes the control unit to perform the desired control, such as method steps according to the present invention.
    The computer program usually forms part of an end computer program product, the computer program product comprising an appropriate storage medium 121 (see Fig. 1B) with the computer program stored on said storage medium 121. The computer program may be non-volatile stored on said storage medium. The said digital storage medium 121 may, for example, consist of one of the group: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc., and be arranged in or in connection with the control unit, the computer program being executed by the control unit. By changing the instructions of the computer program, the behavior of the vehicle in a specific situation can thus be adapted.
    An exemplary control unit (control unit 230) is shown schematically in Fig. 1B, wherein the control unit may in turn comprise a calculation unit 120, which may consist of e.g. any type of flashlight of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or a single application with a predetermined specific function (ApplicationSpecific Integrated Circuit, ASIC).
    The computing unit 120 is connected to a memory unit 121, which provides the computing unit 120 e.g. the stored program code and / or the stored data calculation unit 120 need to be able to perform calculations, e.g. to determine whether a single error code should be activated. The calculation unit 120 is also arranged to store partial or final results of calculations in the memory unit 121.
    Furthermore, the control unit is provided with devices 122, 123, 124, 125 for receiving and transmitting input and output signals, respectively. These input and output signals may contain path shapes, pulses, or other attributes, which the devices 122, 125 for receiving input signals may be detected as information for processing the computing unit 120. The output signals 123, 124 for transmitting output signals are arranged to convert calculation results from the calculation unit 120 into output signals for transmission to other parts of the vehicle control system and / or the decomponent (s) for which the signals are intended. Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may consist of one or more of a cable; a data bus, such as a CAN bus (ControllerArea Network bus), a MOST bus (Media Oriented SystemsTransport), or any other bus configuration; or by a wireless connection.
    A first exemplary method for diagnosing the fuel system is shown in Fig. 3. The method is exemplified in connection with the fuel system shown in Fig. 2, which is described in more detail below, but is also applicable to other types of fuel systems where parallel fuel pumps are used. The present invention is thus applicable to all types of fuel systems, i.e. even for fuel systems without a transfer tank. Regarding the method 300 in Fig. 3, this begins in step 301, when it is determined whether the fuel system is being diagnosed as damaged. When diagnosing the fuel system is to proceed, the process proceeds to step 302. According to one embodiment, diagnostics of the fuel system may be arranged to be performed continuously according to the present invention as soon as a fuel pump is to be activated or activated. According to one embodiment, the transition from step 301 to step 302 can be arranged to take place e.g. when a signal from a pressure sensor, such as from any of the pressure sensors 228,229 below, indicates abnormally high and / or low pressure, and / or one or more parameters regarding fuel pump control, such as with respect to speed or power consumption, indicate that the system may be malfunctioning. The transition from step 301 to step 302 may also be arranged to be controlled by a detection of the occurrence of interruptions of a certain type in a pressure sensor signal. For example. occurrence of noise signals, e.g. exceeding a certain amplitude some applicable frequency band, is used as a criterion for the transition to step 302. The choice of frequency for analysis edge.ex. be arranged to depend on the prevailing pump speed and / or current flow. This analysis of the pressure signal can thus be arranged to be performed continuously or at applied interval, whereby the diagnosis can be performed when the analysis of the pressure signal indicates that an error may occur. According to one embodiment, the diagnosis according to the invention can be arranged to be performed e.g. at appropriate intervals.
    Furthermore, in cases where more than one pair of parallel fuel pumps is used, as in the example shown in Fig. 2, the fuel system for each pair may be arranged to be diagnosed individually. The method shown can thus be used individually, simultaneously or sequentially, 10 13 for each of the pairs of fuel pumps arranged in parallel described below.
    Fig. 2 shows the fuel system in Fig. 1A in more detail. In the ifig. 2, two main tanks 215A, 215B are used, each of which holds a relatively large amount of fuel, such as e.g. a fuel quantity in the range of 300-100 liters. The use of several tanks can make it possible to obtain a larger fuel leakage capacity than what might otherwise be possible when using a single tank as larger interconnected spaces can constitute a shortage of vehicles, and thus it can be difficult to find a possible location for a single tank of the desired size.
    The two main tanks 215A, 215B are connected to each other via passage 216 in the lower part of the tanks 215A, 215B, whereby fuel can flow from one to the other tank. Likewise, the tanks at the top are connected to each other via a vent filter 214.
    Fuel is sucked up from the main tank 215A, to which thus also the fuel in the main tank 215B flows, via a fuel fitting 2l3. The inlet 2l3 of the fuel fitting 2l3A is arranged arranged far down in the tank, ie. reach the bottom of the tank, to enable as much volume as possible to be absorbed. A certain distance from the bottom of the tank can be advantageous, for example in order to avoid the absorption of gravel, debris and other objects that may have entered the tank. The fuel level in the tank can be determined by using a level sensor 277. The fuel is sucked up by at least one of a pair of parallel arranged fuel pumps 212A, 212B, and the fuel sucked up by the fuel pumps 212A, 212B is pumped via separate water, for example in the present case. sated, to an intermediate tank 209, transfer tank, as above, which is substantially smaller than the main tanks 215A, 215B. Transfer tank 209 size edge.ex. be in the order of 15-50 liters, or e.g. have a size which in relation to the total volume of the main tanks constitutes a volume in the range 1-10%, or 1-5%, the total volume of the main tanks. Furthermore, the transfer tank geometry is presently such that it has a height exceeding, or preferably slightly exceeding, the width and depth, respectively. The transfer tank is thus relatively high and relatively narrow in order to reduce the negative impact of splashing as much as possible.
    The pumps 212A, 212B for transferring fuel from the main tanks 215A, 215B to the transfer tank 209 may advantageously be arranged inside the transfer tank 209, which is indicated by dashed lines in Fig. 2. However, as will be appreciated, this is not the case, and as also realized, Fig. 2h a logical diagram of the fuel system that makes proportional comparisons between different units included in the fuel system can be performed. For example. can show fuel pumps be of the same type. Nor can any conclusions be drawn regarding the physical location of the respective constituent components other than that it is explicitly indicated in the figures that the fuel pumps in the example shown can be arranged in the transfer tank. According to another embodiment of the present invention, however, this is not the case. The fuel pumps 212A, 212B, as well as the fuel pumps 210A, 210B described below, are electrically driven fuel pumps, in which a respective electric motor 222A, 222B, 221A, 221B is used for driving the respective fuel pump below. A fuel pump with an associated electric motor can in practice consist of an integral part.
    The fuel pumps 210A, 210B, which in a manner corresponding to the fuel pumps 212A, 212B are arranged for parallel operation, are used for transferring fuel from the transfer tank 209 to the injection system 101 of the internal combustion engine 101. These electric motor-driven fuel pumps 210A, 210B can also be arranged in the transfer tank 209, as can the fuel filter 211. In the system shown, two pairs of fuel pumps 210A-B, 212A-B are thus shown for transferring fuel from the main tank injection system. By arranging the fuel pumps 2110A, 212B, 212A, 212B, and associated electric motors, the transfer tank 209, the fuel in the transfer tank can be used to cool components, while, conversely, the fuel can be heated by excess heat from electric motors / fuel pumps. The respective fuel pumps, as well as the fuel filter 211, may alternatively be arranged in another applicable place, such as e.g. in any of the main tanks or completely outside the fuel tanks.
    The fuel is conveyed, in the present example, from the transfer tank 209 via a line 218 and a second fuel filter 207 to an injection system, where a high pressure pump (or other mechanical pressure raising device such as a unit injector) 204 pressurizes the fuel to a very high pressure supplied to a common pipe. ) 201 for supplying the combustion chamber of the internal combustion engine via the respective injectors 202.
    The injection system shown in Fig. 2 thus consists of a so-called Common Rail system, which means that all injectors (and thus combustion chambers) are served by the common fuel pipe 201 (Common Rail). The pressure in the fuel pipe 201 can be regulated by using a valve 203. Regarding the fuel filters, their function is not described here, as the function of these is generally known. Excess fuel from the high pressure pump 204 may be returned to the transfer tank 209 (according to the present example), alternatively the main tanks 215A, 215B (indicated by a dashed line 225) via a line 219, 224. Likewise, excess fuel from injectors 202 and / or fuel may be returned excess line 220, 224. The refueled fuel can also consist of lubricating fuel pre-pressure pump 204 and the injectors 202, etc. The refueled fuel is usually heated, whereby this excess heat can be used for heating fuel through flow to the applicable fuel tank as above. Also shown in Fig. 2 are pressure sensors 228 and 229, respectively, intended to determine the pressure of the fuel flow upstream of the respective pairs of fuel pumps operating in parallel.
    The solution shown has the advantage that by using the substantially smaller transfer tank as above, which is thus significantly less sensitive to the sloping fuel or vehicle inclination, together with the use of electrically driven fuel pumps, various advantages can be achieved, such as e.g. improved range by allowing a larger outlet of the main tanks before refilling is required. Furthermore, co-use of electrically driven pumps in itself has advantages with respect to e.g. energy consumption compared with a fuel pump driven by the output shaft of the internal combustion engine.
    When it is determined in step 301 that the fuel system is undiagnosed with respect to the fuel transfer from main tank 215A, 215B to transfer tank 209, step 302 determines a representation of the pressure by means of the pressure sensor 228 before the applicable length t1, i.e. the variations of the representation pressure signal during the time length t1 are determined. This can e.g. have an appearance according to Fig. 4 below.
    The process then proceeds to step 303, where the signal determined in step 302 is filtered with the appropriate filter, such as e.g. an analog or digital filter. For example. a Butterworth type filter or other applicable type can be used, such as e.g. a high-pass filter with a low cut-off frequency, such as. applicable cut-off frequency in the range 0-1 Hz or in the range 0-0.2 Hz. This filtering thus filters out the static, zero-frequency component and, if applicable, the slowly varying part of the pressure signal in order to obtain the noise in the pressure signal as a result after the filtration.
    The process then proceeds to step 304 at the same time as the timer is started. In step 304, the filtered signal is analyzed for amplitude, where this amplitude thus represents the noise amplitude. This is illustrated in Fig. 4, in which an example of a filtered pressure signal is shown, where at time a leakage of the suction side of the fuel pumps 212A, 212B suddenly arises, to cease again at time 70. In general, the pressure difference with respect to the pumped fuel in case of leakage may be , but as can be seen ifig. 4, on the other hand, the noise amplitude changes markedly during the time the leakage occurs, so a leakage can be detected by comparing the noise amplitude with a first amplitude limit nhmy. The amplitude limit nlm fl, shown as a dashed line in Fig. 4, can be set to a value which the noise signal rarely exceeds during normal operation. The amplitude limit nlm fl can e.g. consists of a measured value-based on previous measurements in the same or equivalent system. Furthermore, the amplitude limit nlm fl can be arranged to depend on e.g. pressure and / or fuel pump speed, etc. If it is determined in step 304 that the noise amplitude exceeds the amplitude limit m, a leak can be considered to have occurred, whereby an error indicator, such as a flag in the vehicle's control system, can be activated. an upcoming workshop visit. Furthermore, if the filtered signal does not indicate the presence of a fault, the method can return to step 301 pending re-diagnosis.
    According to one embodiment it may happen that the noise amplitude exceeds the boundary value only once, but according to the illustrated embodiment this is not sufficient, the robustness of the outside error detection can be improved by requiring the amplitude limit nlm fl to be exceeded several times or specified time for a certain time, e.g. a first number of times for a first number of seconds, or a certain percentage of the first number of seconds. This is illustrated in Fig. 3, where a single counter x is counted up each time the boundary value is exceeded. In step 305, it is then determined whether the number of times the border care has been exceeded amounts to some appropriate number xl. As long as the case is not the case, the method returns to step 304, via a step 306, when it is determined whether the time interval t for which the analysis is performed has reached a limit tx, in which the case procedure ends without an error signal being generated. If it is determined in step 305 that the boundary value has been exceeded at least x1 times, it is verified in step 307 that the time limit tx has not been reached, whereby when no error signal indicating error has occurred in the fuel system, step 308 is generated. consists of an activation of an error code in the vehicle's control system. Procedure can then be terminated.
    According to one embodiment, the method shown in Fig. 3 is performed for a certain fuel pump speed, where the diagnosis can be arranged to be performed when the fuel pump is operated at this speed, whereby the noise amplitude can be specifically measured for this speed. According to one embodiment, however, different amplitude limits may be specified for different speeds, whereby diagnostics can be performed at in principle arbitrary 19 times during normal operation of the vehicle. The amplitude limit can also be universal regardless of the prevailing pump speed.
    According to one embodiment, the method shown in Fig. 3 is used as an indication that a leak is likely to occur, whereby when such an indication is generated, further diagnostics can be performed to ensure the error can be performed. This can be done in different ways, and an example is shown in Fig. 5.
    Figs. 5A-B show a step response test, in which Fig. 5A shows the speed of the fuel pumps as a function of time, and in which Fig. 5B shows the corresponding pressure measured with the pressure sensor 228 as a function of time. According to the example, at the time of single gearing of the fuel pumps 212A, 212B to maximum speed, or other applicable speed, a lower speed is required, with the result that the pressure upstream of the fuel pumps 212A, 212B rises. When the pressure has stabilized and thus no increase in pressure occurs, as at time t2 in the example shown, the resulting pressure at / after time t2, the pressure sensor output pressure is indicated by bar curve 501 in Fig. 5B, can be determined, this pressure being compared with an expected pressure , shown in solid line 502 in Fig. 5B.
    In the event that the measured pressure deviates (falls below) the expected pressure, e.g. by any applicable margin, the candida is used as a confirmation of the presence of leakage. The expected pressure can e.g. consist of a calculated pressure, or be determined by empirical measurements in advance. Instead of comparing pressure, the power consumption of the alternative fuel pumps can be compared. The power consumption comparison can also be arranged to be performed as an additional test. In cases where leakage occurs, the load of the fuel pumps will be reduced due to the presence of gas in the pumped liquid, with the result that the power consumption is reduced, which e.g. can be determined by utilizing the fuel consumption of the fuel pumps.
    The present invention can thus be used to determine by means of average frequency analysis the potential occurrence of leakage, whereby further diagnosis, according to one embodiment, can be used to verify the occurrence of leakage. The frequency analysis further has the advantage that it can be performed during normal operation without affecting it.
    In Figs. 3,4,5A-B, identification of a suction leakage downstream fuel pumps 212A, 212B for transferring fuel from main tank to transfer tank has been exemplified. The sample diagnostics can be used analogously to the fuel pumps 210A, 21B for transferring fuel from the transfer tank to the injection system 204. Thus, a corresponding frequency analysis can be performed, where the noise amplitude can be evaluated accordingly to determine the potential for leakage.
    The fuel pumps used for transfer between the main tank and the transfer tank, respectively between the transfer tank and the injection system, can be of different types. For example. The fuel pumps 212A, 212B may be of a larger dimension which do not need to pump fuel continuously, but may be arranged to fill the transfer tank at appropriate intervals, while the fuel pumps 210A, 210B may be arranged to substantially continuously transfer fuel to the injection system. out for different types of pumps.
    This is illustrated in Figs. 6A-D, where Fig. 6A shows pressure variation before and after a leakage which occurs at time t = approx. l6. The pressure leak gives rise to pressure changes, but in the example shown the variations are 21 between approx. l, 10-ca. 1.16 bar, which gives a very small difference that can be very difficult to draw conclusions from.
    Fig. 6B shows a high-pass filtered signal, and as can be clearly seen, a moment after the onset of the leakage, a clear amplitude change in the noise signal occurs, which can be detected in exactly the same manner as described above. However, the example shown in Fig. 6A is an example where further analysis is performed. The signal in Fig. 6B shows after the time t = approx. 22 a clear frequency dependence, which in itself can be used. Once the signal has been filtered, e.g. is filtered once more with a bandpass or low-pass filter in order to filter out high-frequency components. Fig. 6C shows the signal of FIG. 6B after such a bandpass filtering, the low frequency content becomes clearer, and which is further clarified by transformation to the frequency plane, such as e.g. by using FFT (Fast Fourier Transform). This is illustrated in Fig. 6D, when it appears that the leakage thus gives rise to a very clear frequency signal, which can thus be detected and when the amplitude of this can be used in the same way as above as an indication of the presence of leakage. . Also in this case, step response test as above can be performed, the low pressure, after this has been stabilized for any applicable speed as above, can be compared with an expected pressure.
    Likewise, power consumption tests can be performed as above.
    The invention has hitherto been described in connection with the diagnosis of leakage on the suction side of the fuel pumps. However, the invention is applicable for detecting the leakage current on the pressure side of the fuel pumps. For example. leakage may occur at the pre-filter 212 or the main filter 207. These errors are detected in the corresponding manner as described above with respect to frequency analysis, where also transformation to the frequency plane 22 can be used. The amplitude of the bridge signal will also be higher in these cases compared with situations when no leakage occurs, likewise one / several specific frequencies may appear in the signal in the event of a leak as above, and which is detected. Likewise, step response tests can be performed in order to retrieve a second indication of an indicated error. Regarding leakage on the high pressure side, however, a one-step response test is likely to give variations that are within the pressure sensor error margin, ie. the pressure difference between a situation where leakage occurs and where leakage does not occur is so small that conclusions can no longer be drawn with certainty. This means on the other hand that the step response test can be used to distinguish leakage on the pressure side from leakage on the suction side. That is, in the case where the frequency analysis indicates a fault at the same time as the step response test indicates a fault, it can be determined that a leak is on the suction side of the fuel pumps. Conversely, in the fall frequency analysis indicating errors while the step response test is not a clear indication, it can be determined that the leak is on the pressure side.
    Taken together, the invention means that a good indication of what is working incorrectly can be obtained with the invention, and by utilizing the frequency analysis, errors can be identified which can otherwise be very difficult to identify.
    Furthermore, the present invention can be applied in conjunction with a diagnostic method described in the parallel Swedish patent application entitled "PROCEDURE AND SYSTEM PRE-DIAGNOSIS OF A FUEL SYSTEM", with the same filing date as the present application, and the same inventors being described in the present application. type, where the power consumption of a pair of parallel fuel pumps is used to detect malfunction .10 23 Signals from pressure sensors corresponding to the above-mentioned pressure sensors can also be applied to determine the cause of malfunction. Thus, both methods according to the present application and methods according to said application are used in diagnosing said application. .
    Furthermore, signals from more / other pressure sensors in the fuel system than shown above can be used in diagnosing the fuel system.
    Furthermore, as has been mentioned above, the present invention is not limited to fuel systems with transfer tank, the invention is applicable to all types of fuel systems where parallel operating and electrically driven fuel pumps are arranged. Furthermore, more than two, such as e.g. three fuel pumps can be arranged to work in parallel, whereby a representation of power consumption for each fuel pump can be used in the diagnosis.
    Further embodiments of the method and system according to the invention are found in the appended claims. It should be noted that the system can be modified according to various embodiments of the method according to the invention (and vice versa) and that the present invention is not in any way limited to the above-described embodiments of the method according to the invention, but relates to and includes all embodiments within the scope of the appended independent claims.
    权利要求:
    Claims (1)
    [1]
    A method of diagnosing a fuel system wide vehicle (100), said vehicle (100) comprising an internal combustion engine (101) and at least one fuel tank (215A, 215B; 209) for receiving fuel, said fuel system comprising a first fuel pump (212A; 210A) for use in transferring fuel between said first fuel tank (215A, 215B; 209) and said internal combustion engine (101), a second fuel pump (212B; 210B) arranged to operate in parallel with said first fuel pump (212A; 2100A of first fuel). fuel tank (1515A, 155B; 209) and said internal combustion engine (110), and a pressure sensor means (228, 229) arranged in the name fuel system upstream of said first and second fuel pump, characterized in that the method comprises: filtering said signal from said first means (22) of by using a first filter, and - based on said filtered signal determining a single occurrence of a first fuel flow fe l in the said industry system. The method of claim 1, further comprising: - in said filtering, suppressing a zero frequency component in said pressure signal from said first pressure sensor means (228, 229). A method according to claim 1 or 2, further comprising: - in said filtering, suppressing frequency components in said pressure signal from said first pressure sensor means (228, 229) less frequencies in the range 0-0.5 Hz or 0-0.2 Hz. A method according to any one of claims 1-3, further comprising: - comparing the amplitude (nmms) of said filtered signal with a first amplitude (nhml), and - when the amplitude (nmms) of said filtered signal exceeds said first amplitude (nlm fl), generating a single signal indicating a fuel flow fault in said fuel system. The method of claim 4, further comprising: - comparing the amplitude (nmms) of said filtered signal with a first amplitude (nlm fl) for a plurality of consecutive times during a first time period (tx) of said filtered signal, and - when the amplitude (nmms) of said filter filtered signal exceeds said first amplitude (nlm fl) at least a first plurality (xl) times during said first time period, generating a signal indicating a fuel flow error in said fuel system. The method of claim 4, further comprising: - comparing the amplitude (nmms) of said filtered signal with a first amplitude (nlm fl) during a first time period (tx) of said filtered signal, and - when the amplitude (nmms) of said filtered signal exceeds said first amplitude (nlm fl) at least during a certain time of said first time period, generate a single signal indicating a fuel flow error in said fuel system. A method according to any preceding claim, further comprising: - transforming said filtered signal into a frequency plane, and - determining the occurrence of fuel flow errors in said fuel system at least in part based on a frequency analysis of said transformed signal. The method of claim 7, further comprising: - determining the occurrence of fuel flow errors in said combustion system at least in part based on an occurrence of a first frequency in said transformed signal. A method according to claim 7 or 8, further comprising transforming said filtered signal into a frequency plane by using a Fourier transform, such as FFT (Fast Fourier Transform). Method according to one of the preceding claims, further comprising reaching, based on said filtering signal, a fuel flow error is considered to occur: - performing a second, different from said frequency analysis, diagnosis, whereby a signal indicating a well flow error is generated based also on said second analysis. A method according to any one of the preceding claims, further comprising: - controlling said fuel pumps to a first speed, and comparing a resultant pressure determined by means of said pressure sensor-generated signal with a first pressure, wherein the presence of said first fuel flow error is considered to be present when the average the signal fixed pressure differs from said first pressure by a first pressure difference. A method according to any one of the preceding claims, further comprising: - controlling said fuel pumps to a first speed, - comparing a resulting result determined by said pressure sensor generated by said pressure sensor with a 13. 14. 15. 27 first pressure, - wherein the presence of a first fuel flow error is considered to be present when the pressure determined by said pressure sensor-generated signal deviates from said first pressure by more than a first pressure difference, and - in which case the presence of a second fuel flow error is considered to exist when the first pressure sensor not detected by said pressure sensor than a first pressure difference. Method according to any one of the preceding claims, further comprising: - based on said filtered signal, determining a single occurrence of a leakage downstream and / or upstream of said first and / or second fuel pump. A method according to any preceding claim, wherein said vehicle (100) further comprises a transfer tank (209) disposed between said fuel supply system (204) and said at least one first main tank (255A), the method comprising supplying fuel to said main tank (209) to said fuel from said main tank (209). 155A) and from said transfer tank to said fuel supply system (204), said transfer tank (209) being a smaller tank compared to said first main tank (209A), and said first and second fuel pumps being used to transfer fuel from said main source ( transfer tank (209) or from said transfer tank to said fuel supply system (204). A method according to claim 14, wherein a first pre-parallel work arranged pair of pumps is used for transferring fuel from said at least one first 16. 17. 18. 19. 20. 28 main tank (209A) to said transfer tank, and wherein another pair of parallel work arranged pumps are used for transferring fuel from said transfer tank to said fuel supply system (204), each pair of fuel pumps being controlled according to any one of claims 1-13. A method according to any one of the preceding claims, wherein said at least one fuel tank consists of a main tank or a transfer tank arranged between said internal combustion engine and said main tank. A method according to any preceding claim, further comprising: - performing said filtering of said signal from said first pressure sensor means when a filtered pressure signal indicates the presence of noise signals in a first frequency band, such as a speed and / or flow dependent frequency band. 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 of claims 1-17. A computer program product comprising a computer readable medium and a computer program according to claim 17, wherein said computer program is included in said computer readable medium. A system for diagnosing a fuel system in a vehicle (100), said vehicle (100) comprising an internal combustion engine (101) and at least one fuel tank (215A, 215B; 209) for receiving fuel, said fuel system comprising a first fuel pump (212A; 211); for use in transferring fuel between said first fuel tank (215A, 215B; 209) and said internal combustion engine (101), a second fuel pump (212B; 2110B) arranged to operate in parallel with said first fuel pump (2112A; 2110A) in transferring fuel 29. between said first fuel tank (215A, 215B; 209) and said internal combustion engine (110), and a pressure sensor means (228, 229) arranged in said fuel system upstream of said first and second fuel pump, characterized in that the system comprises means for: filtering said said first pressure sensor means (228, 229) by utilizing a first filter, and - based on said filtered signal determining a presence of a first board nsleflow error in said fuel system. Vehicle (100), characterized in that it comprises a system according to claim 20.
    类似技术:
    公开号 | 公开日 | 专利标题
    DE60117090T2|2006-11-02|Method for determining leaks in an injection system with distribution line in an internal combustion engine
    GB2538735B|2019-06-12|Variable sensitivity pressure differential detection in a vehicle aftertreatment system
    CN101281053B|2013-03-27|System for detecting failures in fuel systems
    CN105189969A|2015-12-23|Anomaly determination system and anomaly determination method
    CN105402115A|2016-03-16|Automotive electronic fuel pump detection system
    SE1150562A1|2011-12-22|Process of an HC dosing system and an HC dosing system
    WO2018017010A1|2018-01-25|Fuel system for an internal combustion engine
    SE536319C2|2013-08-20|Device and method for fault detection in a fuel supply system of a motor vehicle
    SE1350527A1|2014-10-31|Fuel quality detection method and system
    SE1550926A1|2017-01-02|Fuel system diagnostic method and system ii
    CN108204321B|2020-05-19|Fuel oil transfer device
    SE541143C2|2019-04-16|Device for fuel supply and associated process
    US20170335788A1|2017-11-23|Method for checking a parameter correlating with a pressure in a pressure-dependent fluid-conveying system, control device and fluid-conveying system
    SE1550927A1|2017-01-02|Procedure and system for diagnosing a fuel system
    EP2976520B1|2018-05-16|Fuel system for combustion engine and a method for controlling a fuel system
    CN114174656A|2022-03-11|Method for monitoring a fuel supply system of an internal combustion engine and internal combustion engine for carrying out such a method
    CN208651333U|2019-03-26|A kind of filtration system and hydraulic system
    SE537965C2|2015-12-15|Procedure and system for determining the scope of a single vehicle
    SE540260C2|2018-05-15|Fuel system and method for indicating water in fuel by use of a conductivity sensor
    WO2016028211A1|2016-02-25|Method to detect faults relating to mounting of fuel filters
    WO2014168563A1|2014-10-16|Method and device for functional check of fuel supply conduit
    WO2020060471A1|2020-03-26|Method for diagnosing a fuel filter, and control device therefor
    DE102017208635A1|2018-11-22|Exhaust control for a hybrid vehicle with particle filter
    CN108533427A|2018-09-14|A kind of automotive fuel oil system
    CN113404594A|2021-09-17|Intelligent monitoring system and method for power equipment
    同族专利:
    公开号 | 公开日
    WO2017003366A1|2017-01-05|
    SE541174C2|2019-04-23|
    DE112016002216T5|2018-04-19|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE19908352A1|1999-02-26|2000-08-31|Bosch Gmbh Robert|Fuel injection method for an internal combustion engine|
    DE10001829A1|2000-01-18|2001-07-19|Bosch Gmbh Robert|Demand-driven regulation of fuel feed pump in multi-pump systems involves switching auxiliary fuel supply system on depending on main fuel supply system threshold values|
    US6840222B2|2000-05-03|2005-01-11|Robert Bosch Gmbh|Method and device for monitoring a fuel system of an internal combustion engine|
    EP1870586B1|2006-06-16|2018-12-05|Delphi International Operations Luxembourg S.à r.l.|Apparatus for detecting and identifying component failure in a fuel system|
    JP4488017B2|2007-03-16|2010-06-23|株式会社デンソー|Accumulated fuel injection device and accumulator fuel injection system|
    US8483932B2|2009-10-30|2013-07-09|Ford Global Technologies, Llc|Fuel delivery system control strategy|
    法律状态:
    2021-03-02| NUG| Patent has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    SE1550926A|SE541174C2|2015-07-01|2015-07-01|Procedure and system for diagnosing a fuel system|SE1550926A| SE541174C2|2015-07-01|2015-07-01|Procedure and system for diagnosing a fuel system|
    PCT/SE2016/050669| WO2017003366A1|2015-07-01|2016-06-30|Method and system for diagnosing a fuel system ii|
    DE112016002216.6T| DE112016002216T5|2015-07-01|2016-06-30|Method and system for diagnosing a fuel system II|
    [返回顶部]