Patent GB-2489824-A (GB)
Title: Estimating the fuel consumption of a vehicle
Inventor: KEATES JOHN DAVID
IPC: B60R16/023
Filed: 2012-04-05
Abstract: A method of estimating the fuel consumption of a vehicle comprises the steps of estimating an overall power of said vehicle, by estimating a rolling power component, an aerodynamic resistance power component and an acceleration power component, using at least one parameter obtained from an on board diagnostic system of the vehicle; determining the type of fuel used by the vehicle; and estimating said fuel consumption by summing the components of said overall power and dividing by the energy value of the fuel type and by a predetermined engine efficiency value. The rolling power component is the power expended to overcome the friction of the road. The aerodynamic power component is the power expended to overcome air resistance. The acceleration power is the power used to increase the speed of the vehicle. Further claimed inventions comprise: An apparatus for discovering which of a plurality of possible engine load reporting strategies is used by an On-board Diagnostics system in a vehicle with an engine, comprising examining means to examine On-board Diagnostics system parameters, and means to determine the engine load when the engine is operating in such a manner as to substantially maximise the difference between the engine load values which would be produced by the different engine load reporting strategies. A method of estimating an effective frontal area or aerodynamic resistance of a vehicle including an engine comprising; at a substantially constant speed of the vehicle determining the current power of the engine and determining the rolling resistance power to overcome the rolling resistance of the vehicle at that substantially constant speed; subtracting the determined rolling resistance power from the determined total current power to determine the aerodynamic resistance of the vehicle or the effective frontal area. A method for determining the fuel type of a vehicle, comprising obtaining the output parameters of an On Board Diagnostic (OBD) system of the vehicle, and using said output parameters to determine the fuel type used by the vehicle. A method of estimating the mass of a vehicle; said vehicle having motion parameters comprising a vehicle speed parameter, a vehicle acceleration parameter and a maximum acceleration parameter, said vehicle having an engine, said engine having an engine capacity parameter and engine activity parameters comprising an engine speed parameter, a power parameter, a maximum power parameter and an engine load parameter, said method comprising the step of determining a weighted or moving average value of vehicle acceleration parameters taken during qualifying periods wherein at least one of the motion parameters and/or at least one of the engine activity parameters are within a predetermined range and using said weighted or moving average value of vehicle acceleration to estimate the mass of the vehicle. A method of estimating the fuel consumption of an engine in a vehicle, said method comprising the steps of obtaining or estimating an air flow through said engine; calculating a provisional fuel mass estimate by dividing the obtained or estimated air flow by a stoichiometric ratio associated with the fuel type; estimating the fuel consumption by dividing said provisional fuel mass estimate by an oxygen content parameter derived from an analysis of exhaust gases. A method of estimating the fuel consumption of a vehicle comprising collecting data sets each of which relate to a particular different parameter and selectively processing selected data to establish the fuel consumption only if the value of some of the selected data or other data is of a qualifying value.