SE538336C2 - Procedure and system for fuel pump control - Google Patents

Abstract

Summary The present invention relates to a method of fuel pump control in a fuel system at a vehicle (100), said vehicle (100) comprising an internal combustion engine (101) and an internal combustion engine (101) associated with said internal combustion engine (101) at the vehicle (204). further comprising a first main tank (215A) for receiving fuel and a first fuel pump (212A; 210A) for use in transferring fuel between said first main tank (215A) and said fuel supply system (204). A second fuel pump (212B; 210B) is arranged to operate in parallel with said first fuel pump (212A; 210A) in transferring fuel between said first main tank (215A) and said fuel supply system (204), and the method comprises: by means of said first (212A; 210A) and second (212B; 210B) fuel pumps based at least in part on a representation of a combined efficiency of said first (212A; 210A) and second (212B; 210B) fuel pumps.

Description

FIELD OF THE INVENTION The present invention relates to a method of fuel pump control in a fuel system according to the preamble of claim 1. The invention also relates to a system and a vehicle, as well as the invention according to the invention. for fuel systems for wide vehicles, and in particular for 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.

With regard to fuel systems, it is generally the case that in many vehicles of today a fuel pump arranged in connection with the internal combustion engine is used for sucking up fuel, when the fuel pump is mechanically coupled to the internal combustion engine and is driven by the drive shaft of the internal combustion engine. This solution means that the fuel pump must be able to pump a relatively large amount of fuel already at low rotational speeds, ie. bearing rotation 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 starter motor is working for the internal combustion engine to be able to start at all. This in turn means that the fuel pump during travel will be oversized, and thus continuously pumps a large amount of fuel which then has to be diverted and returned to the fuel tank. This excess pumping leads, as will be appreciated, to undesirable losses.

Furthermore, a fuel pump driven by the internal combustion engine output shaft, if it starts to suck air, e.g. due to the low fuel level, start cavitating with the consequence that the pump does not start sucking fuel without being stopped first, which means that the vehicle must be stopped before the fuel supply can be resumed. In order to avoid such situations, a fuel reserve can be applied which at least partially reduces the risk of the fuel pump starting to suck air.

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. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of fuel pump control in a fuel system. This object is achieved by a method according to claim 1.

The present invention relates to a method for 10 fuel pump control in a fuel system of a vehicle, said vehicle comprising an internal combustion engine and a fuel supply system associated with said internal combustion engine, the vehicle further comprising a first main tank for receiving fuel and fuel said first main tank and said fuel supply system. A second fuel pump is arranged to operate in parallel with said first fuel pump in the transfer of fuel between said first main tank and said fuel supply system, and the method comprises: - controlling the transfer of fuel by said first and second fuel pump at least in part based on each contract. other fuel pump.

According to the above, there are disadvantages with the use of internal combustion pumps driven by the output shaft of the internal combustion engine. Such problems can be mitigated by the use of an electrically powered fuel pump, whereby the electrically driven pump can be started / stopped if necessary. Furthermore, in particular with regard to heavy vehicles, operational reliability is a very important parameter, and as will be appreciated, a functioning fuel supply is also a very important parameter for operational safety. For this reason, according to the present invention, a system is applied in which two parallel-working and electrically driven fuel pumps are used for the transfer of fuel from the vehicle's fuel tank to the said fuel supply system, such as e.g. one fuel injection system. The fuel pumps are arranged for individual control through individual control of the respective associated electric motor. By utilizing fuel pumps operating in parallel, e.g. a redundancy, whereby it is possible for fuel to be transferred even when one of the fuel pump is malfunctioning.

The present invention, however, relates to a method which, in addition to increasing the operational reliability, results in an economical consumption, economical operation of the parallel fuel pumps, and according to a preferred embodiment below, a method which can further improve the operational reliability.

Regarding economic operation of the fuel pumps, the invention is achieved according to the invention by controlling the combined work of the fuel pumps based on a representation of the efficiency of the fuel pumps, the fuel pumps being controlled based on their total efficiency. Thus, the combined efficiency can e.g. maximized. The efficiency of a fuel pump can vary greatly over its operating range, and by utilizing the present invention, the fuel pumps can be controlled towards as good a common efficiency as possible. Thus, the manner in which the fuel pumps are controlled will depend on the specific operating point, such as with respect to the resulting flow and differential pressure across the fuel pumps to be produced.

Since operational reliability is of very great importance, according to an embodiment of the invention, in addition to efficiency, additional parameters are also taken into account when determining how the fuel pumps are to be controlled. According to one embodiment, control of the fuel pumps takes into account at least one parameter regarding the pourability / service life of the pumps. This parameter can e.g. consists of the number of start, stop and / or operating cycles, ie. the number of threads and each pump has been started and stopped. In general, start / stop means wear and tear, and by e.g. distribute the operation between the pumps in the event of an operation when only one pump needs to be in operation, the wear can be kept even. Likewise, the total operating time can be used as a parameter, whereby the pumps e.g. can be regulated so that the total pump operation over time is distributed evenly between the pumps. Another parameter that can be taken into account when controlling the pumps is the prevailing temperature, varvidt.ex. a temperature sensor arranged in / at each pump / electric motor, alternatively a modeled temperature, eg based on an ambient temperature for pump or electric motor and model of temperature change in operation / out of operation, the interaction of the can pumps is controlled so that undesirably high temperatures, with associated risk of damage , in particular with regard to the windings of the electric motor, can be avoided as far as possible.

According to one embodiment, an at least one main tank, arranged transfer tank, also called "catch-tank" or "tech-tank", also referred to below said fuel supply system, is said, the method comprising supplying fuel to the said transfer tank from said first feed tank. fuel supply system from said transfer tank, and wherein said transfer tank is represented by a smaller tank compared to said first fuel tank. The volume of the transfer tank may, for example, 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 susceptible to fuel sludge movements in the tank due to movements and wave slopes. When the transfer tank is full, it therefore functions as a buffer when the fuel can not be sucked out of the main tank, e.g. due to low fuel level in combination with sloping surface, whereby fuel can be transferred to the fuel supply system from the transfer tank even when fuel in 10 said first main tank is not available, and whereby the transfer tank eats can be refilled 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 filling is required. According to one embodiment, said first and second fuel pumps, respectively, are used to transfer fuel to said transfer tank from said at least one main tank. According to another embodiment, said first and second fuel pump, respectively, are used for transferring fuel from said transfer tank to said fuel supply system. According to one embodiment, a first pair of parallel operating fuel pumps is used for the transfer of 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.

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 can 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 the appearance of the efficiency of a fuel pump. Fig. 5 shows an example of the overall efficiency appearance of a pair of parallel operating fuel pumps. 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 l00 shown schematically in Fig. 1 comprises a driveline with a single-combustion engine l01, which in a conventional manner, via a shaft outgoing on the internal combustion engine l01, usually via a flywheel l02, is connected to a gearbox l03 via a single clutch l06. The internal combustion engine l01 is controlled by the vehicle's control system via an engine control unit 115. Likewise, in the present example, clutch l06 and gearbox, respectively, are controlled by a control unit ll6.

Furthermore, a shaft l07 emanating from the gearbox l03 drives drive wheels ll3, l4 via a final gear l08, such as e.g. unusual differential, as well as drive shafts l04, l05 connected to the aforementioned final gear l08. Fig. 1A thus shows a driveline of a non-specific type, but the invention is applicable to all types of drivelines, and also to all types of vehicles, as long as these are driven by an internal combustion engine.

The vehicle shown also includes a fuel system, which is shown below. 1A shows two main fuel tanks 215A, 215B from which fuel is supplied to a combustion supply system arranged at the internal combustion engine 110, in the present example a injection system 204, via a transfer tank 209. The functions of the fuel system are controlled by a control unit 230. Further details in the example are shown below. .

According to the above, the present invention relates to the control of fuel pumps for transferring fuel from one or more fuel tanks to a fuel sludge supply system by utilizing 10 of parallel operating fuel pumps. The method according to the invention may be arranged to be performed by any control unit present in the vehicle control system of the vehicle, and may for example be arranged to be performed by the control unit 230 or alternatively applicable control unit existing at the vehicle, such as the engine control unit 115. The control unit can thus consist of any existing control unit in the control system of the vehicle. The invention can also be implemented in a control unit dedicated to the present invention.

Generally, such control systems consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECUs), or controllers, and various components arranged on the vehicle 100. Such a control system can thus comprise a large number of control units, and the responsibility for a specific function can be divided into more than one control unit. For the sake of simplicity, Fig. 1A shows only 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 may e.g. may depend on signals from different sensors, examples of such sensors being described below in connection with Fig. 2. 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. The control can also depend on output signals from one or more other control units, such as data regarding the vehicle's scale in front of the vehicle received from the control unit 117.

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 a 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 the computing unit 120 needs 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 waveforms, pulses, or other attributes, which the input devices 122, 125 for receiving input signals are 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 to 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 exhaling 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.

An exemplary method for controlling fuel pumps according to the invention is shown in Fig. 3, and the invention will be exemplified in connection with the fuel cutting system shown in Fig. 2. The present invention is applicable to all types of fuel systems, i.e. also in the case of fuel systems without a transfer tank, and is a particularly applicable wide fuel system of the type shown in Fig. 2, and the variants of fuel system described in connection with Fig. 2.

Regarding the method 300 in Fig. 3, this begins in step 301, when it is determined whether well sludge transfer by means of fuel sludge pumps is to be performed. When the fuel sludge transfer is to be carried out, the process proceeds to step 302. According to one embodiment, regulation of the fuel sludge pumps during fuel sludge transfer may be arranged to be carried out continuously according to the present invention as soon as a fuel sludge pump is to be activated. Furthermore, in cases where more than one pair of parallel fuel pumps is used, the respective pairs can be arranged to be regulated individually. The method shown can thus be used individually for the pairs of fuel pumps arranged in parallel shown 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 quantity of fuel in the range of 300-100 liters. The use of several tanks can make it possible to obtain a larger total fuel capacity than might otherwise be possible when using a single tank as larger interconnected spaces can constitute a shortage of vehicles, and whereby it can thus be difficult to find a possible place 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 the fuel in the main tank 215B also flows, via a fuel fitting 213. The inlet 213A of the fuel fitting 2l3 is preferably arranged longitudinally down in the tank, i.e. close to the bottom of the tank, to enable as much volume as possible to be absorbed. Some 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 217. 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, in the present example, through a separate filter. method, to an intermediate tank 209, transfer tank, as above, which is substantially smaller than the 12 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 pumps 212A, 212B are arranged for parallel operation, are used 13 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 to the injection system. By arranging the fuel pumps 210A, 210B, 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 recycled fuel can also consist of lubricating fuel pre-pressure pump 204 and the injectors 202, etc. The recycled fuel is usually heated, whereby this excess heat can be used for heating fuel by returning it to the applicable fuel tank as above.

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 fuel is thus to be pumped, parameters 30 for use in determining the control of the fuel pumps are determined in step 302, the procedure continuing to step 303 for determining how the fuel pumps are regulated, the control then being performed in step 304. The procedure can then be returned to step 301. . The process shown may be arranged to be performed separately for each pair of fuel pumps 210A-B; 2l2A-B.

Regarding the determination of parameters in step 302, the pre-use in determining the control of the fuel pumps can consist of parameters of different types. As mentioned above, regulation according to the invention is performed based at least on the total efficiency of the fuel pumps. Regarding the efficiency, there are often available fuel pumps of the type shown, where the efficiency can depend on e.g. pressure and flow. Such data can be found available from the supplier or e.g. measured up, and ifig. 4 shows an example of an efficiency characteristic of an exemplary fuel pump. The x-axis represents flow, the y-axis represents the pressure difference across the fuel pump, and in graphene angles the efficiency, where the corresponding pump rotation speed is also indicated. Such data are preferably stored for each pump, either in tabular form, alternatively a model of the fuel pump's efficiency can be applied, where the modeling can be performed in the appropriate manner by using e.g. a pump model from the prior art.

By utilizing such data regarding the two pumps in a parallel operating pair, a total efficiency of the two pumps can be determined. This can be determined in an appropriate manner, and e.g. is calculated using the following equations: qT = q1 + q2 (eq. 1) where qT constitutes the total pumped flow and qpqz the flow before the respective pump.A fl. = AR == AQ (eq. 2) Ie. the pressure difference across the pumps is the same when connecting in parallel.

The efficiency can then be written as: qAP q AP q q: fm 'fi fl z: ilm' fi fl zqTAPT qTAPT qT qT OUT (eq. 3) 16 When OUT is the total efficiency and UNUZ the efficiency for the respective pump. Fig. 5 shows an example of a resultant diagram for a certain pressure AE determined by utilizing the above equations, where total efficiency is shown as a function of pump speed and when total flow is also indicated. Such representations of aggregate efficiency can thus be obtained for applicable differential pressures across the fuel pumps.

In step 302, e.g. a control of the fuel pumps which entails a maximization of the total efficiency of the fuel pumps is determined, whereby the respective pumps can be controlled based on this result. This can e.g. achieved by look-up in tabulated care or by solution of an optimization problem, which can be performed in an appropriate manner and with e.g. boundary conditions in the form of maximum pump speed c. Depending on the appearance of the total efficiency, the result can be that one pump at a time is activated at e.g. lower flows, alternatively that the pumps are activated simultaneously but with different loads.

Thus, the operation of the parallel fuel pumps can be optimized for each moment / change in pressure / flow, with the result that long-term energy consumption is optimized. According to the above, this optimization can be performed individually for each pair of fuel pumps in systems of the type shown in Fig. 2.

According to one embodiment, however, the present invention is not only used for optimizing energy consumption, but also pre-optimization from a operational reliability perspective. This is achieved by, in addition to optimization based on efficiency, also daring into additional parameters.

There are a number of factors that affect the life of an electrically powered fuel pump. In particular, the service life is determined by the service life of the components included, and in the case of an electrically driven pump, this consists primarily of the bearing and motor. The component with the shortest service life will determine the service life of the pump. The service life of the constituent components is affected by various factors, and according to one embodiment, empirical tests are performed to determine the impact of various factors on the service life. Such data can also be found at least partially available via, for example, the pump manufacturer. In determining, different considerations can be taken into account, and a cost function can also be applied to advantage to minimize the “cost” with respect to pump operation, whereby pump operation can thus be optimized based on set criteria.

Examples of factors that affect the components of the fuel pump are e.g. regarding bearings of the pump load, rotational speed, number of operating cycles, lubrication and operating temperature. Regarding electric motors, this is the factor that has the greatest impact on the service life of motor winding temperature. If insufficient cooling is obtained, the winding temperature will rise, with the risk of damage as a result. The factors that primarily affect the winding temperature consist of applied current and ambient temperature.

From a regulatory point of view, the factors that can be directly affected are load and rotational speed. The lower these years, the lower the resulting temperature of the pump / electric motor will be, and the need for lubrication will also decrease.

According to the present invention, a cost function can be applied when different factors are weighted. In general, wide motor vehicles, such as cars, trucks, buses or the like, are often applied to cost functions in different optimization algorithms in order to determine control parameters for controlling different vehicle functions, and such methods can thus be applied here as well, where input weights are calculated and / or fixed. In this case, feel e.g. the end tail tails / stops as a bulb meter, since the service life of the pump / electric machine is a direct relay read to the end operation cycles. Similarly, common operating time e.g. is also used as a perimeter, as well as temperature, operating time, load, etc. also change In how the pump is regulated, it is felt as a fencing, whereby, for example, large regulatory changes are felt to be "punished" for reducing the occurrence of such events.

The regulation is always performed as a cost-cutting function where one or two factors are taken into account when determining how the fuel pumps are to be controlled. The food chains know e.g. is calculated through utilization of a quadratic dietary network function or even applicable dietary network function, whereby the regulation feels like a common weighting of pumpärnäs' common energy consumption, wear and tear e.g. expressed in pump recirculation count, measured / calculated pump temperature etc. tail / stop and risk override, where this risk is known to be higher than average age / operating time etc. The resulting control of pump counters will thus come with time, e.g. feel the resultant end-of-life diet function will be the same as a side effect cream feel accepted when the pump is worn out if this reduces the risk of breakage.

In principle, the regulation feels like a mainstay should follow a "valley gang" in the boardroom, and e.g. happen continuously. In systems also shown in Fig. 2, the type of pump may be controlled in different ways, where 2110A, 210b supplying the engine may be continuously in operation while the pumps 212A, 212B which fill the tank are not continuously connected. stationary / intermittent. 19 Eg. operation of the pumps 212A, 212B can, as far as possible, be arranged so that filling of the transfer tank takes place during engine braking, ie. when the fuel supply to the internal combustion engine is switched off, then the energy for driving the fuel pumps is available free of charge from the generator. In this regard, the control unit 230 may be arranged to continuously receive data regarding the scale in front of the vehicle from the control unit which handles such information. This information can e.g. consists of map data together with positioning data, alternatively another applicable description of the nature of the scale in front of the vehicle. For example, it is becoming more common for vehicles to include a so-called Look Ahead (LA) function, a forward-looking function, which controls various vehicle functions such as cruise control functions based on how the wave looks in front of the vehicle. This forward-looking function, or similar function, can thus be used so that the front control unit 230 with information about how the wave in front of the vehicle is out, whereby operation of the pumps for filling the transfer tank can be controlled as far as possible towards wave sections which can be performed free of charge. In the present example, this functionality is provided by a control unit 117 (Fig. 1A).

As has been mentioned above, however, the present invention is not limited to fuel tank systems with transfer tank, the invention is applicable to all types of fuel system in which parallel operating and electrically driven fuel pumps can be provided.

Further embodiments of the method and system according to the invention are found in the appended claims. It should also be noted that the system may be modified according to various embodiments of the method according to the invention (and vice versa) and that the present invention is thus in no way limited to the embodiments of the invention described above, but relates to and includes all embodiments within the scope of the appended independent claims.

Claims (18)

A method for fuel pump control in an industry system riding a vehicle (100), said vehicle (100) comprising an internal combustion engine (101) and an industry feed system (204) associated with said internal combustion engine (101), the vehicle (100) further comprising At least a first main tank (215A) for receiving bransie and a first bransie pump (212A; 210A) for use riding. transfer of fuel between said first main tank (215A) and said fuel supply system (204), characterized in that a second fuel pump (212B; 210B) is arranged to operate in parallel with said first fuel pump (212A; 210A). said first main tank (215A) and said fuel supply system (204), the method comprising a tax to: - regulate the transfer of bransie by means of said. first (212A; 210A) and second (212B; 210B) fuel pumps At least in part based on a representation of a combined efficiency of said first (212A; 210A) cob second (21213; 2100) fuel pump, said fuel transfer being regulated based also on at least one parameter regarding the service life of said fuel pumps. The method of claim 1, further comprising: - controlling said first (212A; 210A) (Doh second fuel pump (2120; 2100) based on a total efficiency determined based on an individual efficiency of said first (2121; 210A) and audra, respectively. . (2120; 2100) fuel pump. The method of claim 1 or 2, further comprising determining said aggregate effect for said first (212A; 2100) and others. (212B,: 2100) brauslepump 21 haserat pa. a modeled and / or tabulated representation of the efficiency of said first (212A; 210A) and second (21213,; 210B) heat pumps, respectively. Procedure according to any of the preceding claims, vaxvid. said Efficiency consists of a speed and / or flow and / or differential pressure dependent efficiency. A method according to any preceding claim, further comprising controlling the operation of said first (212A; 210A) and second (212B; 210B) fuel pump by utilizing a cost function, said cost function providing a function of AtmAnstone efficiency and at least one parameter relating to the service life of the said first (212A; 210A) and second fuel pumps, respectively (212B; 210B). Procedure according to any one of the preceding claims, vaxvid. said at least one parameter relating to the service life of said first and / or second fuel pump comprises one or more of: 1. a radiating and / or operation related temperature for said first and / or second brake pump; 2. challenge start and / or stop and / or operating cycles for said first and / or second industry pump; 3. a dr: ft time, such as an accumulated dxift time, for the said first and second fuel pumps, respectively; - .., -, - speed rid drft of the named fir sta and / or other hranslepump. A method according to any one of the preceding claims, further comprising, yid said government: 1. weighted efficiency with a first weight and respectively of said atmlnstone a parameter regarding longevity. with. a second weight. 22 8. A method according to any one of the preceding claims, further comprising, according to the said government: - weighted efficiency with a first weight and respectively of said at least one parameter with respect to a second weight with a second weight, wherein the first and second weights are arranged therein. to change over time. A method according to claim 8, wherein said weights are arranged such that rendering is performed to a lesser extent based on efficiency -idmfirt with based on lifespan with increasing total operating time and / or increasing number of operating cycles for said first and / or second noise pump. . A method according to any one of the preceding claims, wherein said vehicle (100) further comprises taking at least one first main tank (215A) arranged between said fuel supply system (204) and said at least one main tank (215A). transfer tank (209), the method comprising supplying fuel to said transfer tank (209) from said first main tank (215A) and Iran said transfer tank to said fuel storage system (204), wherein said. transfer tank (209) constitutes a -IdmfOrt with ndmnda first main tank (209A) smaller tank, and wherein ndmnda first and second hrdnslepump are used for Transferring brdnsie from ndmnda first main tank (215A) to ndmnda transfer tank (nnmd transfertan to ndmnda fuel supply system (204), The method of claim 10, wherein a first. For parallel work arranged pairs of pumps are used for Transfer of fuel Iran mentioned at least one main tank (209A) to said transfer tank, and in other pairs arranged for parallel work used pumps for Transfer of fuel from ndmndd transfer tank to 23 named. bralislematningssvstem (204), wherein. habit pair of bronze pumps is controlled according to the requirements of claims 1-10. Passing according to the name of the hazardous tray, further comprising controlling the transfer of fuel from said main tank to said transfer tank at least in part based on data relating to the road driving the vehicle (100), the fuel being transferred when the industry feed1 to said internal combustion engine is shut off. Computer program comprising program code, which when said program code is executed in a computer produces the species named. computer performs the procedure according to any one of claims 1-12. A computer program product comprising a computer age medium and a computer program according to claim 13, wherein said computer program is anatrate. i ndmnda computerldsbara medium. A system for fuel pump control in an industry system at a vehicle (100), said vehicle (100) comprising a combustion engine (101) and an industry feed system (204) associated with said combustion engine (101), the vehicle (100) further comprising a first main tank (215A) for receiving fuel and a first fuel pump (212A; 210A) for use in passing fuel between said first. main tank (21571) and named. fuel supply system (204), characterized in that the vehicle comprises a second fuel pump (2123; 210B) arranged to operate on: ralielite with said first fuel pump (212A; 210A) in transferring bran between said first main tank (21571) and said industry feed system (204) , and wherein the system comprises means for alt: - regulating the transmission of branish mete 1st said first (21271; 21071) and other (212B; 210B) branish pump atmAnstone partly based on a representation of a total efficiency of said first (212A; 210A) and other 24 (21213; 21013) bransie pump, - means for regulating the said transfers of bransie based also on At least one parameter concerning the service life of the name. bransiepumpar, r A system according to claim 15, wherein said transfer tank (209) is constituted by a tank with a head which is constituted by a junction with the width and the depth, respectively, the higher height. A system according to claim 15 or 16, wherein the size dr of the transfer tank (209) is in the order of 15-50 liters, or of a size corresponding to the combined volume of one or more main tanks (Thr. = ', A, 21513). volume in the range 1-10%, or 1-5%, of the total volume of said main tanks (215A, 21513). 18. System according to any ay. claims 15-17, wherein said industry supply system (204) is generated by an industry injection system. Vehicle (100), characterized in that it comprises a SySLeM according to claim 15. 106 106 215, 209 204 FIG. 'IA 100 21 101 117 16 103 13 5B 107, 10 2/6