Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F9/00—Measuring volume flow relative to another variable, e.g. of liquid fuel for an engine
  • G01F9/008—Measuring volume flow relative to another variable, e.g. of liquid fuel for an engine where the other variable is the flight or running time
• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
  • G07C5/00—Registering or indicating the working of vehicles
  • G07C5/08—Registering or indicating performance data other than driving, working, idle, or waiting time, with or without registering driving, working, idle or waiting time
  • G07C5/0816—Indicating performance data, e.g. occurrence of a malfunction
  • G07C5/0825—Indicating performance data, e.g. occurrence of a malfunction using optical means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K6/00—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines
  • B60K6/20—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
  • B60K6/22—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs characterised by apparatus, components or means specially adapted for HEVs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F19/00—Calibrated capacity measures for fluids or fluent solid material, e.g. measuring cups
  • G01F19/002—Measuring spoons or scoops
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
  • G06Q10/00—Administration; Management
  • G06Q10/04—Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem"
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
  • G06Q10/00—Administration; Management
  • G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
  • G06Q10/00—Administration; Management
  • G06Q10/10—Office automation; Time management
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
  • G06Q50/00—Information and communication technology [ICT] specially adapted for implementation of business processes of specific business sectors, e.g. utilities or tourism
  • G06Q50/40—Business processes related to the transportation industry
• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
  • G07C5/00—Registering or indicating the working of vehicles
  • G07C5/08—Registering or indicating performance data other than driving, working, idle, or waiting time, with or without registering driving, working, idle or waiting time

Definitions

• the present invention relates to a hybrid system for vehicles, and in particular to a method for determining a fuel
• the invention relates also to a system and a
• Hybrid vehicle is a vehicle which uses two or more sources of power and/or fuel.
• a common type of hybrid vehicle comprises electric hybrid vehicles, which have a first power-generating source, e.g. a combustion engine, and one or more electrical machines, the latter being used to generate driving force which is conveyed to the vehicle's powered wheels.
• a first power-generating source e.g. a combustion engine
• electrical machines the latter being used to generate driving force which is conveyed to the vehicle's powered wheels.
• electrical machine can regenerate electrical energy for feeding back to the vehicle's electrical system.
• This regenerative braking affords the advantage that the energy generated can be used to charge up an energy store for storage of electrical energy. Energy stored in the energy store can be utilised by the electrical machine on the occasion of a subsequent acceleration and thereby reduce the load upon the combustion engine, with consequent reduction in fuel
• An object of the present invention is to propose a method which solves the above problem. This object is achieved by a method according to claim 1.
• the present invention relates to a method for comparing a fuel consumption of a first vehicle with a second vehicle, which first vehicle has a first energy converter in the form of a combustion engine to generate a first driving force for propulsion of said first vehicle, and at least a second energy converter in the form of a first electrical machine to
• said second vehicle having only one energy converter to generate driving force for its propulsion, in the form of a combustion engine which is substantially identical with said first combustion engine.
• the fuel consumption of the hybrid vehicle is thus compared with the fuel consumption which would have resulted from propulsion of the same vehicle, i.e. a vehicle equipped with a substantially identical combustion engine, and a preferably also identical gearbox, when driven along the same stretch of road.
• essential power train components i.e. combustion engine and gearbox, and preferably the same power train transmission ratio, it is possible to arrive at a very exact measure of amounts of fuel saved, and hence of cost of fuel saved, resulting in a simple way of presenting to the vehicle' s driver and/or owner the profitability of investing in a hybrid vehicle.
• the fuel saving may be presented graphically on a display to the vehicle's driver, thereby providing him/her with
• the fuel saving may for example be expressed in terms of total cumulative savings since the vehicle was first put into operation, or in terms of saving during a particular journey or period of time, e.g. a current month.
• the fuel saving may be presented as an amount of fuel and/or be
• the fuel saving may also be divided into savings in different situations.
• data may also be sent to the vehicle's owner, e.g. via an RTI (Road Traffic Informatics) system.
• the method comprises comparing a driving force delivered by the electrical machine with a driving force delivered by the combustion engine and thereby determining a difference in fuel consumption based on said driving forces delivered respectively by said electrical machine and
• Fig. la depicts a power train in a vehicle with which the present invention may with advantage be used.
• Fig. lb depicts an example of a control unit in a vehicle control system.
• Fig. 2 is a diagram of the fuel consumption of a combustion engine as a function of engine speed and torque.
• Fig. 3 depicts a method example according to the present invention.
• the power train in a hybrid vehicle comprises not only the components pertaining to a conventional vehicle but also a hybrid portion in the form of various further components, e.g. electrical machine, power electronics unit for running the electrical machine, energy store etc. These components are relatively expensive, with the natural consequence that the procurement cost of the hybrid vehicle is higher than that of a similar vehicle with no hybrid portion.
• the combustion engine and the electrical machine are the combustion engine and the electrical machine.
• the present invention resolves this by determining the hybrid vehicle's fuel saving relative to a conventional vehicle which apart from the hybrid portion is identical, when the conventional vehicle is driven along the same stretch of road as the hybrid vehicle.
• the power train of the parallel hybrid vehicle in Fig. la comprises a combustion engine 101.
• the combustion engine 101 is connected to a gearbox 103 in a conventional way, via an output shaft 102 from the engine 101.
• Gearboxes in heavy vehicles often take the form, as in the embodiment depicted, of a "manual" gearbox 103 in which gear changing is effected automatically (by means of the vehicle's control system).
• the vehicle 100 comprises also a clutch 106 for selectively connecting the output shaft 102 of the engine 101 to the gearbox 103.
• the clutch 106 is automatically controlled by the vehicle's control system, but it might also be manually controlled, since control systems in vehicles with a clutch which is controlled manually (by the driver) can in a known way effect gear changes with the clutch closed, i.e. without using the clutch.
• the automatically controlled clutch 106 is controlled by means of a clutch actuator (not depicted) on the basis of control signals from a control unit 116.
• the vehicle further comprises drive shafts 104, 105 which are connected to its powered wheels 113, 114 and which, as in a conventional combustion engine system, are powered by a gearbox output shaft 107 via an axle gear which may for example take the form of a conventional differential 108.
• the vehicle has also a pair of front wheels 111, 112.
• the vehicle depicted in Fig. la has also an electrical machine 110 connected to the input shaft 109 of the gearbox 103, "downstream" of the clutch 106, which means that the gearbox input shaft 109 can be driven by the electrical machine 110 even when the clutch 106 is open.
• Parallel hybrid vehicles can thus transmit power to powered wheels 113, 114 from two separate power sources
• the vehicle may be propelled by either power source individually, i.e. either by the combustion engine 101 or by the electrical machine 110.
• the electrical machine is situated upstream of the clutch or downstream of the gearbox.
• the vehicle cannot be run on electric drive alone if the electrical machine is situated upstream of the clutch.
• the vehicle may also be of a type with conventional automatic gearbox, with the electrical machine situated upstream or downstream of the gearbox.
• the electrical machine 110 may be of any suitable type.
• the electrical machine is a three-phase motor, so the power supply to the electrical machine 110 will be a three-phase power supply.
• Three-phase motors may be of both asynchronous and synchronous types, and a synchronous motor affords the advantage that exact
• the speed of an electrical machine is generally controlled by the frequency of the supply voltage by which the motor is powered, the speed of the electrical machine being directly proportional to that frequency.
• Speed control of an electrical machine thus entails being able to vary the voltage supplied to the motor. In the case of an alternating-current motor, this means that it has to be possible to vary the frequency of the AC supply voltage .
• the motor 110 depicted in Fig. 1 is therefore provided with by a three-phase power supply with variable frequency, generated by means of a power electronics unit 117.
• the electronics unit 117 works against an energy store 118, e.g. one or more batteries, supercapacitors etc.
• the energy store may be adapted to being charged in various different ways, e.g. by regenerative braking by means of the electrical machine 110 and/or by being plugged into an external power source, e.g. a conventional electricity network.
• the power electronics unit 117 depicted may be of a type commonly used in hybrid vehicles and therefore not described in more detail here. Generally speaking, however, the power electronics unit 117, in the case of an AC motor, converts the DC voltage of the energy store 118 to an AC voltage. The conversion is effected by means of a converter device which may for example comprise a number of IGBTs (insulated gate bipolar transistors) which can, by means of suitable
• the electrical machine 110 can thus be used to propel the vehicle 100 at vehicle speeds ranging from zero to maximum speed, or a lower speed, depending on the size of the
• Control systems in modern vehicles usually further comprise a communication bus system consisting of one or more
• Such a control system may comprise a large a number of control units, and the
• responsibility for a specific function may be divided among two or more of them.
• Fig. la only depicts, apart from the previously mentioned control unit 116, four further electronic control units 115, 119, 126, 127.
• the control unit 119 controls the engine 101, while the control unit 116 controls the clutch 106 and the gearbox 103 (two or more from among engine, gearbox and clutch may alternatively be arranged to be controlled by one and same control unit or by undepicted other control units) .
• the control unit 115 controls electrical machine/power electronics unit/energy store.
• the control units 115, 116, 119 can communicate with one another via said communication bus system, as illustrated by lines drawn between them in the diagram.
• the control unit 126 controls the vehicle's RTI (Road
• Transport Informatics system, which covers functions such as traffic information and vehicle navigation.
• the control unit 126 is also responsible for
• the RTI control unit is normally responsible for the vehicle's communication with, for example, a fleet management portal, making it possible for data to be transmitted to said portal for evaluation by the vehicle's owner.
• the control unit 127 controls data display on the instruments provided in the driving cab, which often comprise not only conventional indicating instruments but also one or more displays. By means of the control unit 127 it is possible for fuel consumption data to be presented on these one or more displays, or a display specifically intended for presentation of fuel consumption data to the vehicle's driver.
• Control units of the type referred to are normally adapted to receiving sensor signals from various parts of the vehicle, e.g. gearbox, engine, electrical machine, clutch and/or other control units or components of the vehicle.
• the control signals generated by control units normally depend both on signals from other control units and on signals from
• control exercised by the control unit 115 over the electrical machine 110/power electronics 117 etc. will depend on, for example, information received from, for example, the control units 119, 126, 127 and/or 116.
• the control units are further arranged to deliver control signals to various parts and components of the vehicle, e.g. to the electrical machine 110 and the power electronics unit 117, in order to control them.
• the present invention may be implemented in any of the above control units, or in some other suitable control unit in the vehicle's control system.
• the functions of the invention may also be divided among two or more of said or other control units.
• the control is often governed by programmed instructions.
• the computer programme takes typically the form of a computer programme which, when executed in a computer or control unit, causes the computer/control unit to effect desired forms of control action, e.g. method steps according to the present invention.
• the computer programme usually takes the form of a computer programme product 109 which is stored on a digital storage medium 121 (see Fig. lb), e.g. ROM (read-only memory) , PROM (programmable read-only memory) , EPROM (erasable PROM) , flash memory, EEPROM (electrically erasable PROM), a hard disc unit etc., in combination with or in the control unit, and which is executed by the control unit.
• ROM read-only memory
• PROM programmable read-only memory
• EPROM erasable PROM
• flash memory e.g. EEPROM (electrically erasable PROM), a hard disc unit etc.
• control unit 127) An example of a control unit (the control unit 127) is
• the calculation unit 120 is connected to a memory unit 121 which provides it with, for example, the stored programme code 109 and/or the stored data which the calculation unit 120 needs in order to be able to perform calculations.
• the calculation unit 120 is also arranged to store partial or final results of calculations in the memory unit 121.
• the control unit 115 is further provided with respective devices 122, 123, 124, 125 for receiving and sending input and output signals.
• These input and output signals may comprise waveforms, pulses or other attributes which the input signal receiving devices 122, 125 can detect as information and which can be converted to signals processable by the calculation unit 120. These signals are thereafter conveyed to the calculation unit 120.
• the output signal sending devices 123, 124 are arranged to convert signals received from the
• calculation unit 120 in order, e.g. by modulating them, to create output signals which can be transferred to other parts of the vehicle's control system and/or the
• Each of the connections to the respective devices for receiving and sending input and output signals may take the form of one or more from among a cable, a data bus, e.g. a CAN (Controller Area Network) bus, a MOST (Media Orientated Systems Transport) bus or some other bus configuration, or a wireless connection.
• a data bus e.g. a CAN (Controller Area Network) bus, a MOST (Media Orientated Systems Transport) bus or some other bus configuration, or a wireless connection.
• a method example 300 according to the present invention is depicted in Fig. 3.
• the basic concept of the present invention is to compare the fuel consumption of the hybrid vehicle with the fuel consumption which would arise from driving the same vehicle with no hybrid portion along the same stretch of road.
• the method 300 begins at step 301, which determines whether the fuel consumption difference is to be determined.
• the fuel consumption difference may for example be arranged to be determined at equal intervals of time, e.g. every second, every fifth second or some other suitable interval.
• the interval may also be arranged to be varied when the vehicle is in motion.
• the fuel consumption difference may be determined at shorter intervals in situations such as powerful accelerations which involve rapid changes in the operating point of the engine and/or the electrical machine.
• the method moves on from step 301 to 302, which determines the current fuel consumption of the hybrid vehicle 100, followed by step 303, which determines fuel consumption of a
• the difference in fuel consumption is determined at step 304 and is presented to the driver and/or the vehicle owner at step 305. The method may then go back to 301 for the next determination (at a point in time or over a period of time) .
• determining consumption explicitly for both types of vehicle, and
• steps 302-304 may be combined in a single step, as exemplified by the equations below.
• fuel may be saved by means of the hybrid system in various different situations. Examples of such situations are described below. It should however be appreciated that fuel savings may vary greatly from situation to situation. It should also be noted that at the same time as there being advantage in presenting the composite fuel saving for all of the fuel-saving situations, there may also be advantage in presenting fuel savings for only one or a limited number of the situations described below.
• embodiment example determines only the fuel saving achieved in situations where the engine's torque exceeds a predetermined value, since only this determination can provide a good indication of fuel saved.
• An alternative embodiment uses a combination of, for example, all of the calculation approaches exemplified below.
• the electrical machine is situated on the gearbox input shaft, making it possible for the combustion engine and the electrical machine either individually or in conjunction to drive the vehicle's powered wheels.
• the electrical machine helping the engine to propel the vehicle reduces the engine's fuel requirement.
• Fig. 2 is a diagram illustrating an example of how fuel consumption of an engine example may vary with its speed and torque delivered T.
• the fuel consumption is depicted as fuel flow in litres per hour. As may be seen in the diagram, the distance between the fuel flow curves is constant or
• the efficiency at point c is the same as at point a (the fuel flow per kilowatt power/newtonmetre developed is the same)
• the fuel saving due to the help from the electrical machine will be directly proportional (linear) to the torque (the power output) contributed by the electrical machine.
• the efficiency of injected will be linear to torque delivered. If the torque generated by the engine's combustion decreases by half, it means that fuel injected likewise decreases by half.
• the efficiency of a combustion engine is usually substantially constant at a given engine speed, in which case the fuel saved by means of the hybrid portion can be estimated at
• FuelSaved Y FuelRate ⁇ n) « ElMotorTorque(n) ⁇ ⁇ (/) eq ( 1 )
• At may as above vary in length depending on the particular driving situation.
• FuelSaved fuel saved, expressed in litres, cumulatively over the period t covered by the calculation.
• FuelR tein current fuel consumption at the time of measurement, e.g. expressed in litres per second. Fuel consumption may for example be determined by means of a model of the engine, which may be stored in the vehicle's control system as a
• EngineTorque(n) is the engine's torque for a specific measuring point/measurement period (n) .
• El Motor Torque(ri) is the electrical machine's torque for a
• Equation (1) might thus also be written
• FuelSaved Y FuelRate(n)x — —x At (/)
• the saving over the period ⁇ will be similar to the electrical machine's contribution relative to the engine's contribution. If the electrical machine delivers the same torque as the engine, the saving will thus be equal to the engine's current fuel consumption. If for example the
• Equation (1) for calculating fuel saving may be used so long as the engine' s torque is the same, or substantially the same, at the operating point at which the engine would operate with no contribution from the electrical machine, e.g. point a above, as at the operating point at which the engine operates with contribution from the
• the difference in the engine's efficiency between points a and c may for example be allowed to deviate by some value which depends on desired accuracy, e.g. 1%, i.e. the fuel consumption need not be completely linear to the engine's power output.
• the diagram in Fig. 2 may for example be stored in vehicle's control system in a suitable way, e.g. in the form of values for different (power output) torque/engine speed combinations, to make it possible on each occasion (n) to determine by means of said stored data whether equation (1) is applicable for use in the calculation in order to achieve the desired accuracy.
• equation (1) there may be certain parts of the engine's operating range in which it is not appropriate to employ equation (1) .
• only positive electrical machine torque is included in the calculation when using equation (1) .
• ElMotorTorque 0.
• calculation according to equation (1) is preferably only employed when the engine delivers positive power train torque. Even if the engine's combustion delivers positive torque, this may still mean, owing to engine friction and other losses, that the torque contribution to the power train is negative, i.e. there is engine braking, in which case saving according to equation (1) is not relevant.
• equation (1) may be arranged to be applicable only when the engine's torque, EngineTorque , or the torque delivered by its flywheel, is greater than a predetermined threshold value. This depends for example on the possibility of the engine's efficiency at low torque being comparatively low, so further compensation as below may be required.
• the engine usually also idles, often at an operating point with impaired efficiency. Depending on the operating point at which the engine would have run with no contribution from the electrical machine, the accuracy may therefore be impaired in this situation. If the engine would have run at an operating point with higher efficiency, the equation will not fit exactly (i.e. there is a difference in engine efficiency between the operating points), so a
• compensation factor may be applied where necessary.
• the calculated value may be compensated by - — verkn.grad e to cater for the fuel saving not being exactly the value arrived at by the equation.
• Other types of recalculation factors may of course also be used.
• the vehicle may also be propelled entirely electrically without the engine being run, in which case the saving will be the fuel which the engine would have consumed at the
• the result of the sum in equation (1) may be summarised in a parameter which is preferably not zeroed during the truck's service life. This means that the total fuel saved to date can be presented to the driver and/or the vehicle owner. The result may also be saved in the form of a parameter
• the vehicle may also be provided with current propellant costs, e.g. input of current propellant prices by its driver when refuelling. Knowing the propellant price makes it possible to present not only savings in terras of litres of fuel but also savings in economic terms.
• the fuel price may for example be obtained via some suitable wireless link, e.g. by means of the RTI system.
• a further example of a situation in which the hybrid portion of the power train may cause a fuel saving is when the vehicle is set in motion from stationary.
• the first is the elimination of energy losses due to clutch slip.
• the clutch normally closes enough to transmit the maximum torque which the engine can deliver at idling speed. This clutch position is then maintained until the gearbox input shaft reaches the engine's idling speed, whereupon the clutch closes completely. This clutch slip results in energy losses in the form of friction heat.
• the other factor is the fact that the
• FuelSavedldle FuelRateldle x At (I) .
• This increased fuel consumption may be calculated as
• fan and pump functions may be required for the hybrid portion of the power train (e.g. for cooling of electrical machine/energy store) , leading to electrical losses from the vehicle's conventional electrical system (usually a 24V system in heavy vehicles) .
• This energy loss may be compensated for when there is positive engine torque (when "negative" engine torque is required, charging may be effected at no cost by using the electrical machine for braking) .
• the power consumed in operating such ancillaries can be calculated in conventional and known ways.
• the total power consumption arising due to these ancillaries can then be converted to a corresponding engine torque by dividing by 2*n* EngineSpeed .
• the fuel losses can then be calculated by means of equation (1) above, in which
• the extra rolling resistance due to the increased weight of the hybrid vehicle has also to be taken into account.
• the rolling resistance may likewise be converted in a known way to a power output and be aggregated with the above ancillary losses when using equation (1) above.
• the increased weight due to the hybrid portion of the power train (which varies from vehicle to vehicle and depends on energy store capacity, but may in an example represent about 200 kg) also causes increased energy expenditure during acceleration and when driving uphill. So long as no active braking takes place, however, this energy is stored as extra kinetic energy which can be utilised on, for example, downhill runs to accelerate the vehicle, or to charge the energy store by means of the electrical machine. If however the stored kinetic energy is braked away, these losses have also to be taken into account.
• a further aspect to be catered for in the calculation is that in hybrid vehicles the electrical machine can be used to move the engine's operating point in order to improve emission characteristics. In certain cases, this saves fuel as
• diesel fuel is often used to burn particle filters clean. By moving the engine's operating point it is possible to raise exhaust temperatures without having to use diesel fuel to burn the particle filter clean. In this case the amount of diesel fuel which would normally have been used to burn the filter clean is added to the above.
• Each individual emission strategy requires a calculation algorithm of its own for saved fuel.
• fuel saving may be expressed as fuel saved during the particular journey, average fuel saving per hour or distance, or total fuel saved since zero reset.
• the driver may preferably do a trip data reset in a conventional way. In the control unit, however, there is no zeroing of the
• calculated parameters may likewise be sent to, for example, a fleet management portal, making it possible for the vehicle's owner to follow up saved fuel.
• Statistics may also be calculated about the routes, the driver/drivers or the type of driving for which the hybrid system is most advantageous and therefore most quickly saves against the increased purchase cost.
• the invention is described above in relation to a parallel hybrid system.
• the invention is nevertheless applicable to other types of hybrid system, provided that they incorporate a combustion engine and provided that fuel consumption is compared with a vehicle provided with a substantially
• a combustion engine which is provided with starter motor/generator and is otherwise similar to the engine of the hybrid vehicle is regarded in this context as identical with the engine of the hybrid vehicle.
• the engine may nevertheless be similar with regard to cylinder volume etc. for the purposes of being regarded as similar according to the present invention.

Landscapes

• Engineering & Computer Science (AREA)
• Business, Economics & Management (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Strategic Management (AREA)
• Human Resources & Organizations (AREA)
• Economics (AREA)
• Entrepreneurship & Innovation (AREA)
• General Business, Economics & Management (AREA)
• Marketing (AREA)
• Theoretical Computer Science (AREA)
• Tourism & Hospitality (AREA)
• Quality & Reliability (AREA)
• Operations Research (AREA)
• Mechanical Engineering (AREA)
• Transportation (AREA)
• Fluid Mechanics (AREA)
• Development Economics (AREA)
• Game Theory and Decision Science (AREA)
• Automation & Control Theory (AREA)
• Combustion & Propulsion (AREA)
• Mathematical Physics (AREA)
• Chemical & Material Sciences (AREA)
• Educational Administration (AREA)
• Data Mining & Analysis (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Primary Health Care (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=44834382

Family Applications (1)

Country Status (3)

Families Citing this family (3)

Family Cites Families (2)

• 2010
  • 2010-04-23 SE SE1050404A patent/SE537307C2/sv not_active IP Right Cessation
• 2011
  • 2011-04-18 WO PCT/SE2011/050473 patent/WO2011133095A1/en not_active Ceased
  • 2011-04-18 EP EP11772325.4A patent/EP2561485A4/de not_active Ceased

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events