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
  • G01F9/001—Measuring volume flow relative to another variable, e.g. of liquid fuel for an engine with electric, electro-mechanic or electronic means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B1/00—Engines characterised by fuel-air mixture compression
  • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
  • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder

Definitions

• the invention is a process and a device for producing a decision- variable that gives the driver possibilities for choosing such running conditions and parameters for the engine and vehicle under dynamical driving conditions that makes possible a considerable increased milage.
• the decision-variable consists of a calculation of the instantaneously consumed total energy per driven unit of lenght.
• the conventional FCI fuel consumption indicator
• Futiiermore part of the energy-content of the fuel has been used to change the kinetic and potential energy of the vehicle . This energy has not yet been wasted, it has only been converted from chemically to mechanically stored energy vhich still is at the disposition to move the vehicle without any futher fuel consumption.
• a indicator which shows the real losses gives the possibilities for adjusting the driving conditions so that the efficiency becomes the best possible.
• Consumed energy for a given utility function eg covered distance
• the conversion factor between amount of fuel and stored energy is for instance choosen to correspond to the best efficiency of the engine and transmission.
• the purpouse of the invention is, to present for the driver at every moment such information that ' is useful guidance in the choice of such driving parameters for the engine that considerable reduction of used fuel during various driving conditions is achieved.
• the data which is best suited to give guidance for choice of driving parameters comes from a calculation of the instantainously consumed total energy per covered unit of lenght. The desired result is obtained by the process according to patent claim 1 -5 or a device according to patent-claim 6 - 9.
• Fig 1 shows the specific fuel consumption (g/kWh) for a typical Otto engine as function of tourque and engine-speed. Data for this figure is obtained from ref. 1 for the general features and ref. 2 for specific data in some points.
• Fig. 2 is a diagram showing sensors, datapaths, processing unit and indicators and display according to this invention.
• IND is the display-value presented to the driver s iSOistance covered during the measuring interval B is to the carburetor or equivalent delivered fuel during the measuring interval.
• OMPI b is during the measuring interval in the carburetor temporarily stored fuel (eg in the acceleration pump).
• K2 is the conversion factor from mechanical energy to amount of fuel.
• m is the total mass of the vehicle, in certain cases including a virtual mass corresponding to the angular momentum of the wheels.
• A is the sum of the acceleration of the vehicle and the earth gravitational acceleration projected on the speed vector.
• the earth gravitational acceleratin can be excluded, in this case the potential energy of the vehicle is left out.
• term 2 is more simply calulated according to the formula
• K3 is a function of battery voltage and includes charging efficiency and conversion factors.
• U is the battery voltage
• I is the charging current to the battery.
• t is the time-duration of the measuring interval.
• H is the summed angular momentum of the wheels etc.
• v1 is speed of the vehicle at the end of the measuring interval.
• vo is speed of the vehicle at the start of the measuring interval.
• _ is the angular momentum for the rotating Darts of the engine.
• n1 is the rotating speed of the engine at the end of the measuring interval, no is the rotating speed of the engine at the start of the measuring interval.
• Term 1 consists of used fuel per driven unit of lenght during the measuring interval.
• Term 2 gives the change in the sum of potential and kinetic energy per driven unit of lenght during the measuring interval.( In certain cases the potential energy can be neglected).
• Term 3 is energy stored in battery per driven unit of lenght under the measuring interval. This term can in many cases be neglected but where it is of importance one must take into account the charge-retention and efficiency of the battery..
• Term -4 is the change during the measuring interval in kinetic energy per driven unit of lenght in the form of rotational energy in wheels etc. This can often be approximated with a virtual mass that is added to the total mass m of the vehicle. Under hill-climbing this approximation gives a small error which usually can be neglected .
• Term 5 is the change during the measuring interval in rotational energy in the rotating parts of the engine and transmission per driven unit of lenght. This should be included up to the amount that this stored energy could be used for propelling t ' he vehicle forward without consuming any fuel. Normally the internal friction of the engine is so great that it instead has a breaking effect, and in this case this term should not be included.
• Term 6 etc. are other forms of during the measuring interval per driven unit of lenght stored energy which later can be put to useful work thereby saving fuel.
• the fuelflow to the engine is measured by flowmeter 1 which
• the processing unit 2 contain registers, of which 4 is used to accumulate the total number of fuel pulses 3, and register 5 is used to count the fuel pulses 3 under the measuring interval. Covered distance is measured by a magnetic or optical encoder
• Encoder 6 which is mounted between the speedometercable and the speedometer. Encoder 6 delivers a binary electrical way-pulse
• I Accelerometer 10 is mounted and adjusted in such a way that it only measures the acceleration along an axis parallel . to the road-surface and along the longitudinal axis of the vehicle.
• the output-signal 11 from the. accelerometer 10 is a binary coded 8 bit word including a sign bit.
• a correction has to be made with the amount of fuel temporarily stored in any acceleration-pump.
• On that pump is mounted an position-encoder 13 which converts the position of the pump-membrane into a binary signal 14 with 4 bits resolution.
• the position of the pump-membrane is read by the processing unit 2 at the end of every measuring interval.
• Register 18 in the processing unit 2 is a real-time clock that is used for control.
• control-panel 15 is connected to the processing unit 2.
• Indication of the choosen program is done by signals form the processing unit 2 on a number of signal-lamps 16.
• processing unit 2 The result of the calulations done in processing unit 2 is presented as figures on digital display unit 17.
• the processing unit can have several different programs.
• the parameter that could have to be adjusted often is the total weight of the vehicle, as it varies with the load.
• This weight is for instance adjusted with a number corresponding to the deviation from a standard weight.
• the duration of the measuring interval dt x 2 seconds can be specified with the exponent n, which is stored in a register 20.
• the measuring interval is calculated and put into register 19.
• OMPI calculates the instantanious total energy-consumption per driven km will be presented.
• register 4 for the total number of fuel-pulses
• register 5 for the number of fuel-pulses during the measuring interval
• reister 12 for the accumulated acceleration
• register 8 for the total number of way-pulses
• register 9 for the number of way-pulses during the measuring interval.
• the calculation and presentation-cycle starts when register 18 has reached zero. Then until the next fuelrpulse arrives the way-pulses are registered. This eliminates a rounding error which might be considerable as each fuel-pulse represents a relatively great amount of fuel. By choosing such a small ds that makes the number of way-pulses during the measuring interval great enough, the rounding error due to the way-pulses can be reduced enough in comparison with other sources of uncertainty.
• a conventional fuel-consumption-indicator would indicate a large fuel-consumption/km during the acceleration-phase. If we use the conventional fuel-consumption- indicator to indicate how to save fuel we would be coaxed to accelerate the vehicle very slowly to make the meter show a low consumption (the invention would then indicate greater energy-consumption than in the first case ). Under these circumstances the engine works with low part-load and consequently has bad efficiency. Only a minor part of the energy-content of the fuel is converted into useful mechanical work at the wheels. This means that, for a certain useful work done more fuel has to be spent than in the first case, when the engine was allowed to work with best efficiency.
• OMPI consumptionmeter indicates 18 liter/100km while the invention indicates 7 liter/100km. As can be seen the correction for the kinetic energy is considerable.

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• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Measuring Volume Flow (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=20340973

Family Applications (1)

Country Status (3)

Cited By (1)

Families Citing this family (12)

• 1980
  • 1980-05-14 SE SE8003651A patent/SE451904B/sv not_active IP Right Cessation
• 1981
  • 1981-11-02 EP EP19810903001 patent/EP0092543A1/de not_active Withdrawn
  • 1981-11-02 WO PCT/SE1981/000320 patent/WO1983001686A1/en unknown

Non-Patent Citations (1)

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