SE1650099A1

SE1650099A1 - A method and system for controlling air supply

Info

Publication number: SE1650099A1
Application number: SE1650099A
Authority: SE
Inventors: Jeddi Tehrani Hossein; VADASZ Richard; Björkman Mathias
Original assignee: Scania Cv Ab
Priority date: 2016-01-28
Filing date: 2016-01-28
Publication date: 2017-07-29
Also published as: DE102017000379A1; SE541399C2

Abstract

The present invention relates to a method for controlling air supply of a vehicle (1; 1a). The air processing system (200) is configured to receive compressed air (A) distributed by means of a compressor (20) operable by means of a drive member (10). The air processing system is configured to distribute the compressed air to different air consumers (C1, C2, C3, C4, C5) for different vehicle functions, certain vehicle functions being necessary for allowably operating the vehicle (1; 1a). The method comprises the steps of: determining, for a certain set of vehicle functions, whether compressed air distributed to the consumers (C1, C2, C3, C4, C5) is provided at a certain pressure level and/or at a certain amount and/or has a pressure change within a certain rate for operating the vehicle functions necessary for allowably operating the vehicle; and, if it is determined that the pressure provided is below said certain pressure level and/or the amount of air provided is below said certain amount and/or the pressure change is above said certain rate, disabling one or more vehicle functions not necessary for allowably operating the vehicle so as to provide pressure at said certain pressure level and/or amount of air at said certain amount and/or pressure change within said certain rate.The present invention also relates to a system for controlling air supply. The present invention also relates to a vehicle. The present invention also relates to a computer program and a computer program product.(Fig. 3)

Description

A |\/IETHOD AND SYSTEM FOR CONTROLLING AIR SUPPLY TECHNICAL FIELD The invention relates to a method for controlling air supply according to thepreamble of claim 1. The invention also relates to a system for controlling airsupply. The invention also relates to a vehicle. The invention also relates to acomputer program and a computer program product.

BACKGROUND ART Vehicles such as heavy vehicles are usually equipped with a so called airprocessing system to which compressed air is distributed by means of acompressor operated by a drive member such as a combustion engine, anelectric motor or the like. The air processing system is configured to distributethe compressed air to different air consumers for different vehicle functions.Certain vehicle functions are necessary for allowably operating the vehicle,for example the brake function. lf compressed air supplied to the consumersis not supplied at a desired air pressure level and all consumers continueconsuming air, the vehicle will need to stop due to low pressure in brakecircuits resulting in the brake function of the vehicle not functioningsatisfactory.

US20100074764 discloses a compressed air supply system for a commercialvehicle, wherein particular consumer circuits can be decoupled selectivelyfrom the rest of the compressed air supply system.

There is however a need for improving control of air supply systems ofvehicles.

OBJECTS OF THE INVENTION An object of the present invention is to provide a method for controlling an airsupply system which improves drivability of the vehicle in that the times thevehicle need to stop due to low pressure level for consumers for vehiclefunctions being necessary for allowably operating the vehicle.

An object of the present invention is to provide a system for controlling an airsupply system which improves drivability of the vehicle in that the times thevehicle need to stop due to low pressure level for consumers for vehiclefunctions being necessary for allowably operating the vehicle.

SUMMARY OF THE INVENTION These and other objects, apparent from the following description, areachieved by a method, a system, a vehicle, a computer program and acomputer program product, as set out in the appended independent claims.Preferred embodiments of the arrangement are defined in appendeddependent claims.

Specifically an object of the invention is achieved by a method for controllingair supply of a vehicle. An air processing system is configured to receivecompressed air distributed by means of a compressor operable by means ofa drive member. The air processing system is configured to distribute thecompressed air to different air consumers for different vehicle functions,certain vehicle functions being necessary for allowably operating the vehicle.The method comprises the steps of: determining, for a certain set of vehiclefunctions, whether compressed air distributed to the consumers is providedat a certain pressure level and/or at a certain amount and/or has a pressurechange within a certain rate for operating the vehicle functions necessary forallowably operating the vehicle; and, if it is determined that the pressureprovided is below said certain pressure level and/or the amount of air provided is below said certain amount and/or the pressure change is abovesaid certain rate, disabling one or more vehicle functions not necessary forallowably operating the vehicle so as to provide pressure at said certainpressure level and/or amount of air at said certain amount and/or pressurechange within said certain rate.

During normal operation when compressed air is distributed to different airconsumers for different vehicle functions, certain vehicle functions beingnecessary for allowably operating the vehicle, i.e. when compressed air isdistributed to a certain set of vehicle functions of consumers, the pressure ofthe compressed air distributed to the consumers is changing within a certainrange and within a certain rate. The air pressure may e.g. vary within a rangeof 9-12 bar. During normal operation of such pressure distribution the rate ofchange of the pressure will not exceed a certain level. Thus, the pressure willnot drop at a rate or speed exceeding a certain rate level/speed level. lf it is determined that the pressure change is above said certain rate, e.g. isdropping at a rate above said certain, it will result in the pressure dropping toa pressure level below a level for operating the vehicle functions necessaryfor allowably operating the vehicle. Thus, the term “for operating the vehiclefunctions necessary for allowably operating the vehicle” comprises operatingthe vehicle functions necessary for allowably operating the vehicle at acertain point of time after the determination. The term “for operating thevehicle functions necessary for allowably operating the vehicle” comprisescontinuously being able to operating the vehicle functions necessary forallowably operating the vehicle for a certain time.

Thus, if it is determined that the pressure change is above said certain rate,e.g. is dropping at a rate above said certain rate, the disabling of one or morevehicle functions not necessary for allowably operating the vehicle may bedone when the pressure level is within the normal pressure range such that itthereby can be avoided to reach a pressure level necessary for operatingallowably operating the vehicle. Reasons for compressed air distributed to the consumers not being provided at a certain pressure level and/or at acertain amount and/or has a pressure change above a certain rate foroperating the vehicle functions necessary for allowably operating the vehiclemay comprise the compressor not being able provide maximum capacity, thisproblem generally occurring when the drive member for driving thecompressor being an electric drive member for electrically driving thecompressor. An electric drive member may advantageously be used for ahybrid vehicle or an electric vehicle. Reasons for the compressor not beingable to operate at maximum capacity may be due to malfunction of theelectric drive member, malfunction of the electric drive member being causedby e.g. too high temperature, low oil pressure, problems with powerelectronics/inverter such as power electronics/inverter becoming too hot.Reasons for the compressor not being able to operate at maximum capacitymay be due lack of available power/energy for the electric drive memberwhich may be due to low battery level, battery being too cold, battery beingtoo hot, power for operating the electric drive member not being sufficientdue to other units necessary and essential for vehicle operation such as 24 Vdc/dc converter, cooling liquid pump, auxiliary units necessary for the vehiclesuch as electric machine necessary for operating e.g. a crane or the like,garbage compressor, cooling arrangement or the like.

Reasons for compressed air distributed to the consumers not being providedat a certain pressure level and/or at a certain amount and/or has a pressurechange above a certain rate for operating the vehicle functions necessary forallowably operating the vehicle may comprise leakage in one or more circuitsfor consumers and/or too many consumers being used at the same time suchthat maximum capacity of the compressor is not sufficient to provide the certain pressure level.

Functions necessary for allowably operating the vehicle comprises safetycritical functions such as the brake function, the brake system of the vehiclebeing supplied with air compressed air and thus constituting consumer.

Functlons necessary for allowably operating the vehicle comprises safetyfunctions for legally operating the vehicle such as the exhaust after treatmentsystem, the exhaust after treatment system being part of the powertrain, thepowertrain comprising the engine and transmission, being supplied with compressed air and thus constituting a consumer.

By disabling one or more vehicle functions not necessary for allowablyoperating the vehicle so as to provide pressure at said certain pressure leveland/or amount of air at said certain amount and/or pressure change withinsaid certain rate drivability of the vehicle is improved in that the stops due tolow pressure for consumers for vehicle functions necessary for allowablyoperating the vehicle are reduced. The vehicle will thus be able to drive forlonger times without stops.

According to an embodiment of the method the step of disabling one or morevehicle functions not necessary for allowably operating the vehicle isperformed in accordance with a predetermined priority sequence. Herebydrivability of the vehicle may be optimized in that stops will be reduced andvehicle functions not necessary for allowably operating the vehicle not beingrequired to be disabled will be the most necessary functions for the particularvehicle.

According to an embodiment of the method the step of determining, for acertain set of vehicle functions, whether compressed air distributed to theconsumers is provided at a certain pressure level and/or at a certain amountand/or has a pressure change within a certain rate for operating the vehiclefunctions necessary for allowably operating the vehicle comprises the step ofdetermining the operational status of the compressor so as to determine apossible pressure and/or amount of air to be provided by said compressor tosaid certain set of vehicle functions. Reasons for the compressor not beingable to operate at maximum capacity may be due to malfunction of theelectric drive member, malfunction of the electric drive member being causedby e.g. too high temperature, low oil pressure, problems with power electronics/inverter such as power electronics/inverter becoming too hot.Reasons for the Compressor not being able to operate at maximum capacitymay be due lack of available power/energy for the electric drive memberwhich may be due to low battery level, battery being too cold, battery beingtoo hot, power for operating the electric drive member not being sufficientdue to other units necessary and essential for vehicle operation such as 24 Vdc/dc converter, cooling liquid pump, auxiliary units necessary for the vehiclesuch as electric machine necessary for operating e.g. a crane or the like,garbage compressor, cooling arrangement or the like.

According to an embodiment of the method the step of determining, for acertain set of vehicle functions, whether compressed air distributed to theconsumers is provided at a certain pressure level and/or at a certain amountand/or has a pressure change within a certain rate for operating the vehiclefunctions necessary for allowably operating the vehicle comprises the step ofdetermining the current pressure and/or current pressure change rateprovided in the air processing system. Reasons for compressed airdistributed to the consumers not being provided at a certain pressure leveland/or at a certain amount and/or has a pressure change within a certain ratefor operating the vehicle functions necessary for allowably operating thevehicle may comprise leakage in one or more circuits for consumers and/ortoo many consumers being used at the same time such that maximumcapacity of the compressor is not sufficient to provide the certain pressure level.

According to an embodiment of the method said drive member is an electricdrive member for electrically driving the compressor.

According to an embodiment of the method said drive member is an internal combustion engine.

Specifically an object of the invention is achieved by a system for controllingair supply of a vehicle. An air processing system is configured to receive compressed air distributed by means of a Compressor operable by means ofa drive member. The air processing system is configured to distribute thecompressed air to different air consumers for different vehicle functions,certain vehicle functions being necessary for allowably operating the vehicle.The system comprises means for determining, for a certain set of vehiclefunctions, whether compressed air distributed to the consumers is providedat a certain pressure level and/or at a certain amount and/or has a pressurechange within a certain rate for operating the vehicle functions necessary forallowably operating the vehicle; and means for disabling one or more vehiclefunctions not necessary for allowably operating the vehicle if it is determinedthat the pressure provided is below said certain pressure level and/or theamount of air provided is below said certain amount and/or the pressurechange is above said certain rate so as to provide pressure at said certainpressure level and/or amount of air at said certain amount and/or pressurechange within said certain rate. The air processing system is according to anembodiment comprised in the system for controlling air supply.

According to an embodiment of the system the means for disabling one ormore vehicle functions not necessary for allowably operating the vehiclecomprises means for performing said disabling in accordance with a predetermined priority sequence.

According to an embodiment of the system the means for determining, for acertain set of vehicle functions, whether compressed air distributed to theconsumers is provided at a certain pressure level and/or at a certain amountand/or has a pressure change within a certain rate for operating the vehiclefunctions necessary for allowably operating the vehicle comprises means fordetermining the operational status of the compressor so as to determine apossible pressure and/or amount of air to be provided by said compressor tosaid certain set of vehicle functions.

According to an embodiment of the system means for determining, for acertain set of vehicle functions, whether compressed air distributed to the consumers is provided at a certain pressure level and/or at a certain amountand/or has a pressure change within a certain rate for operating the vehiclefunctions necessary for allowably operating the vehicle comprises means fordetermining the current pressure and/or current pressure change rateprovided in the air processing system.

According to an embodiment of the system said drive member is an electricdrive member for electricaliy driving the compressor.

According to an embodiment of the system said drive member is an internal combustion engine.

The system for controlling an air pressure system is adapted to perform themethods as set out herein.

The system according to the invention has the advantages according to thecorresponding method claims.

Specifically an object of the invention is achieved by a vehicle comprising asystem according to the invention as set out herein.

Specifically an object of the invention is achieved by a computer program forcontrolling an air pressure system , said computer program comprisingprogram code which, when run on an electronic control unit or anothercomputer connected to the electronic control unit, causes the electroniccontrol unit to perform the steps according to the invention.

A computer program product comprising a digital storage medium storing thecomputer program according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention reference is made to the following detailed description when read in conjunction with the accompanying drawings, wherein like reference characters refer to like partsthroughout the several views, and in which: Fig. 1 schematically illustrates a side view of a vehicle according to the present invention; Fig. 2 schematically illustrates a drive member operating a compressorconnected to an air processing system of a vehicle; Fig. 3 schematically illustrates a system for controlling air supply according to an embodiment of the present invention; Fig. 4 schematically illustrates an air processing system of a vehicle receivingcompressed air from a compressor and distributing compressed air to a set of consumers according to an embodiment of the present invention; Fig. 5 schematically illustrates a hybrid vehicle with an electric drive memberoperating a compressor connected to an air processing system distributingcompressed air to consumers according to an embodiment of the present invention; Fig. 6 schematically illustrates a block diagram of a method for controlling airsupply according to an embodiment of the present invention; and Fig. 7 schematically illustrates a computer according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter the term “link” refers to a communication link which may be aphysical connector, such as an optoelectronic communication wire, or a non-physical connector such as a wireless connection, for example a radio ormicrowave link.

Fig. 1 schematically illustrates a side view of a vehicle 1 according to thepresent invention. The exemplified vehicle 1 is a heavy vehicle in the shapeof a truck. The vehicle according to the present invention could be anyvehicle such as a bus or a car. The vehicle according to the present inventioncould be a hybrid vehicle or a conventional non-hybrid vehicle. The vehiclecomprises an air processing system. The vehicle according to the presentinvention could be an electric vehicle. The vehicle comprises a system I forcontrolling air supply according to the present invention.

Fig. 2 schematically illustrates a drive member 10 operating a compressor 20connected to an air processing system 200 of a vehicle, for example avehicle 1 in accordance with the vehicle in fig. 1. The drive member 10 maybe any suitable drive member 10. The drive member 10 is according to anembodiment an electric drive member 10a comprising an electric machine.The drive member 10 is according to an alternative embodiment an internalcombustion engine 10b. The drive member 10 may according to anembodiment be an energy source such as a battery unit.

The air processing system 200 is configured to receive compressed air Adistributed by means of the compressor 20 operated by the drive member 10.The compressor 20 is connected to the air processing system via a feedingline 22 via which said compressed air A is arranged to be fed to the airprocessing system l.

The compressor 20 is operably connected to the drive member 10. Thecompressor 20 is according to this embodiment operably connected to thedrive member 10 via a clutch arrangement 30. The compressor 20 isaccording to an alternative embodiment connected to the drive member via agear arrangement (not shown). The clutch arrangement 30 or geararrangement is used when the compressor 10 is driven/operated by a drivemember which is dependent from other power sources, e.g. the case with theinternal combustion engine which is driving both the transmission and the 11 Compressor or a case with an electric drive member which is arranged to drive/operate the compressor and other units of the vehicle.

The air processing system 200 is configured to distribute the compressed airto different air consumers G1, G2, G3, G4, G5 for different vehicle functions.One air consumer may have one or more vehicle functions. An air consumermay thus have more than one vehicle function. Air consumers comprise e.g.the brake system of the vehicle, the air suspension system of the vehicle, thepowertrain including the transmission/gearbox and the engine. The brakesystem comprises brake functions requiring sufficient air pressure in aircircuits to function correctly and safely. The air suspension system comprisessuspension functions requiring sufficient air pressure in air circuits to functioncorrectly and safely, this suspension vehicle function of the air suspensionsystem thus being necessary for safely operating the vehicle. The airsuspension system may comprise functions for adjusting the level relative tothe ground, which may comprise kneeling which is common for buses. Alevel changing function of the air suspension system such as the kneelingfunction is not a vehicle function which is necessary for allowably/safelyoperating the vehicle. The powertrain comprises functions requiring sufficientshifttransmission/gearbox, and exhaust after treatment system of the internal air pressure in circuits, such as gear functions of thecombustion engine. Gertain vehicle functions are necessary for allowably operating the vehicle such as the brake function of the vehicle.

Fig. 3 schematically illustrates a system I for controlling air supply of avehicle according to an embodiment of the present invention.

The system I comprises or is connected to an air processing system 200.The air processing system 200 is according to an embodiment an airprocessing system 200 in accordance with fig. 2, 4 and 5. The air processingsystem 200 is configured to receive compressed air distributed by means of acompressor operable by means of a drive member. The air processingsystem 200 is further configured to distribute the compressed air to different 12 air consumers G1, G2, G3, G4, G5 for different vehicle functions, certainvehicle functions being necessary for allowably operating the vehicle.

The system I comprises or is connected to the different air consumers G1,G2, G3, G4, G5 for different vehicle functions.

The system I comprises an electronic control unit 100.

The system I comprises means 110 for determining, for a certain set ofvehicle functions, whether compressed air distributed to the consumers isprovided at a certain pressure level and/or at a certain amount and/or has apressure change within a certain rate for operating the vehicle functionsnecessary for allowably operating the vehicle.

The means 110 for determining, for a certain set of vehicle functions, whethercompressed air distributed to the consumers is provided at a certain pressurelevel and/or at a certain amount and/or has a pressure change within acertain rate for operating the vehicle functions necessary for allowablyoperating the vehicle comprises means 112 for determining the operationalstatus of the compressor so as to determine a possible pressure and/oramount of air to be provided by said compressor to said certain set of vehiclefunctions.

Reasons for compressed air distributed to the consumers not being providedat a certain pressure level and/or at a certain amount and/or has a pressurechange within a certain rate for operating the vehicle functions necessary forallowably operating the vehicle may comprise the compressor not being ableprovide maximum capacity, this problem generally occurring when the drivemember for driving the compressor being an electric drive member forelectrically driving An electric drive member the compressor. may advantageously be used for a hybrid vehicle.

According to an embodiment of the system I the drive member is an electricdrive member for electrically driving the compressor. 13 The means 112 for determining the operational status of the Compressor soas to determine a possible pressure and/or amount of air to be provided bysaid compressor to said certain set of vehicle functions comprises means112a for determining malfunction of the electric drive member. l\/lalfunction ofthe electric drive member may be caused by e.g. too high temperature, lowoil pressure, problems with power electronics/inverter of electric drivemember such as power electronics/inverter becoming too hot. The means112a for determining malfunction of the electric drive member may thuscomprise any suitable sensor unit comprising a temperature sensor unit fordetermining the temperature of the electric drive member comprisingdetermining the temperature of the power electronics/inverter.

The means 112 for determining the operational status of the compressor soas to determine a possible pressure and/or amount of air to be provided bysaid compressor to said certain set of vehicle functions comprises means112b for determining available power for the electric drive member. Lack ofavailable power/energy for the electric drive member may be due to lowbattery level, battery being too cold, battery being too hot, or the like. Themeans 112b for determining available power for the electric drive membermay comprise means for determining battery level such as a sensor unit fordetermining battery power, a temperature sensor unit for determining batterytemperature or the like. Lack of available power/energy for the electric drivemember may be due to power for operating the electric drive member notbeing sufficient due to other units necessary and essential for vehicleoperation such as 24 V dc/dc converter, cooling liquid pump, auxiliary unitsnecessary for the vehicle such as electric machine necessary for operatinge.g. a crane or the like, garbage compressor, cooling arrangement or the like.The means 112b for determining available power for the electric drivemember may comprise means for determining required power needed for other units/auxiliary units. 14 The means 110 for determining, for a certain set of vehicle functions, whethercompressed air distributed to the consumers is provided at a certain pressurelevel and/or at a certain amount and/or has a pressure change within acertain rate for operating the vehicle functions necessary for allowablyoperating the vehicle comprises means 114 for determining the currentpressure and/or current pressure change rate provided in the air processingsystem 200. The means 114 may comprise any suitable pressure sensorunit. The means 114 may comprise one or more pressure sensor units.

The system I comprises means 120 for disabling one or more vehiclefunctions not necessary for allowably operating the vehicle if it is determinedthat the pressure provided is below said certain pressure level and/or theamount of air provided is below said certain amount and/or the pressurechange is above said certain rate so as to provide pressure at said certainpressure level and/or amount of air at said certain amount and/or pressure change within said certain rate.

The means 120 for disabling one or more vehicle functions not necessary forallowably operating the vehicle comprises according to an embodiment valvemembers for closing circuit for air supply to functions not necessary forallowably operating the vehicle necessary to provide pressure at said certainpressure level and/or amount of air at said certain amount and/or pressurechange within said certain rate to functions necessary for allowably operatingthe vehicle comprising brake function of the brake system.

Functions necessary for allowably operating the vehicle comprises safetycritical functions such as the brake function, the brake system of the vehiclebeing supplied with air compressed air and thus constituting consumer.Functions necessary for allowably operating the vehicle comprises safetyfunctions for legally operating the vehicle such as the exhaust after treatmentsystem, the exhaust after treatment system being part of the powertrain, thepowertrain comprising the engine and transmission, being supplied with compressed air and thus constituting a consumer.

The means 120 for disabling one or more vehicle functions not necessary forallowably operating the vehicle comprises means 122 for performing saiddisabling in accordance with a predetermined priority sequence. Herebydrivability of the vehicle may be optimized in that stops will be reduced andvehicle functions not necessary for allowably operating the vehicle not beingrequired to be disabled will be the most necessary functions for the particularvehicle.

The means 122 for performing said disabling in accordance with apredetermined priority sequence comprises according to an embodimentpredetermined priorities of functions of consumers, wherein the function notnecessary for allowably operating the vehicle having the lowest priority isdisabled first, wherein, if it is determined that the pressure provided is belowsaid certain pressure level and/or the amount of air provided is below saidcertain amount and/or the pressure change is above said certain rate, thefunction not necessary for allowably operating the vehicle having the secondlowest priority is disabled secondly and so on until pressure at said certainpressure level and/or amount of air at said certain amount and/or pressurechange within said certain rate has been obtained.

According to an embodiment of the system I the drive member is an internalcombustion engine.

The electronic control unit 100 is operably connected to the means 110 fordetermining, for a certain set of vehicle functions, whether compressed airdistributed to the consumers is provided at a certain pressure level and/or ata certain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehiclevia a link 110a. The electronic control unit 100 is via the link 110a arranged toreceive a signal from said means 110 representing data for pressure leveland/or data for amount and/or data for rate of pressure change ofcompressed air distributed to the consumers. 16 The electronic control unit 100 is operably connected to the means 112 fordetermining the operational status of the compressor so as to determine apossible pressure and/or amount of air to be provided by said compressor tosaid certain set of vehicle functions via a link 112A. The electronic controlunit 100 is via the link 112A arranged to receive a signal from said means112 representing data for operational status of the compressor.

The electronic control unit 100 is operably connected to the means 112a fordetermining malfunction of the electric drive member via a link 112a1. Theelectronic control unit 100 is via the link 112a1 arranged to receive a signalfrom said means 112a representing data for malfunction of the electric drivemember comprising temperature data and/or oil pressure data and/or data forstatus of power electronics comprising temperature data.

The electronic control unit 100 is operably connected to the means 112b fordetermining available power for the electric drive member via a link 112b1.The electronic control unit 100 is via the link 112b1 arranged to receive asignal from said means 112b representing data for available power for theelectric drive member comprising data for battery status comprising batterylevel and/or battery temperature and/or data for power being occupied/usedby other units.

The electronic control unit 100 is operably connected to the means 114 fordetermining the current pressure and/or current pressure change rateprovided in the air processing system 200 via a link 114a. The electroniccontrol unit 100 is via the link 114a arranged to receive a signal from saidmeans 114 representing data for current pressure and/or data for currentpressure change rate provided in the air processing system 200.

The electronic control unit 100 is operably connected to the means 120 fordisabling one or more vehicle functions not necessary for allowably operatingthe vehicle if it is determined that the pressure provided is below said certain pressure level and/or the amount of air provided is below said certain amount 17 and/or the pressure change is above said certain rate so as to providepressure at said certain pressure level and/or amount of air at said certainamount and/or pressure change within said certain rate via a link 120a. Theelectronic control unit 100 is via the link 120a arranged to receive a signalfrom said means 120 representing data for disabling one or more vehiclefunctions not necessary for allowably operating the vehicle if it is determinedthat the pressure provided is below said certain pressure level and/or theamount of air provided is below said certain amount and/or the pressurechange is above said certain rate.

The electronic control unit 100 is operably connected to the means 122 forperforming said disabling in accordance with a predetermined prioritysequence via a link 122a. The electronic control unit 100 is via the link 122aarranged to receive a signal from said means 122 representing data fordisabling one or more vehicle functions not necessary for allowably operatingthe vehicle in accordance with a predetermined priority sequence if it isdetermined that the pressure provided is below said certain pressure leveland/or the amount of air provided is below said certain amount and/or thepressure change is above said certain rate.

The electronic control unit 100 is arranged to process the data for disablingone or more vehicle functions not necessary for allowably operating thevehicle if it is determined that the pressure provided is below said certainpressure level and/or the amount of air provided is below said certain amountand/or the pressure change is above said certain rate. The electronic controlunit 100 is arranged to process the data for disabling one or more vehiclefunctions not necessary for allowably operating the vehicle in accordancewith a predetermined priority sequence if it is determined that the pressureprovided is below said certain pressure level and/or the amount of airprovided is below said certain amount and/or the pressure change is abovesaid certain rate. 18 The electronic control unit 100 is operably connected to the respectiveconsumer G1-G5 via links L21, L22, L23, L24, L25, i.e. a link connected tothe respective consumer. The electronic control unit 100 is via one or more ofthe links L21, L22, L23, L24, L25 arranged to send a signal to one or more ofthe consumers G1-G5 representing data for disabling, for said one or moreconsumers, one or more vehicle functions not necessary for allowablyoperating the vehicle if it is determined that the pressure provided is belowsaid certain pressure level and/or the amount of air provided is below saidcertain amount and/or the pressure change is above said certain rate. Thedisabling of one or more functions not necessary for allowably operating thevehicle is preferably performed in accordance with a predetermined priority sequence.

According to an embodiment the electronic control unit is operably connectedto the air processing system 200 via a link 200a. According to anembodiment the electronic control unit can be arranged to send a signal viathe link 200a to the air processing system 200 for disabling one or morevehicle functions not necessary for allowably operating the vehicle so as toprovide pressure at said certain pressure level and/or amount of air at said certain amount and/or pressure change within said certain rate.

Fig. 4 schematically illustrates an air processing system 200 of a vehiclereceiving compressed air from a compressor 20 and distributing compressedair to a set of consumers G1, G2, G3, G4, G5 according to an embodiment of the present invention.

The compressor is operated by means of a drive member 10. The drivemember 10 is according to an embodiment an electronic drive member. Thedrive member 10 is according to an embodiment the internal combustionengine of the vehicle. 19 The air processing system 200 comprises an air dryer device 40 for dryingand filtering the air from particles from e.g. oil from the engine. Thecompressor 20 is connected to the air dryer device 40 via a feeding line 22.

The air processing system 200 comprises a multi circuit protection valve 50connected to the air dryer device 40. The multi circuit protection valve 50 isconfigured to distribute the dried air from the air dryer device 40 via adistribution block 60 to different air consumers G1, G2, G3, G4, G5 fordifferent vehicle functions, certain vehicle functions being necessary forallowably operating the vehicle. The multi circuit protection valve 50 isconfigured to distribute the dried air from the air dryer device 40 via adistribution block 60 to circuits of the different air consumers G1, G2, G3, G4,G5 for different vehicle functions. The consumers comprise e.g. brake systemG1 and air suspension system G2. The multi circuit protection valve 50 isconfigured to distribute the dried air from the air dryer device 40 via adistribution block 60 to different air consumers G1, G2, G3, G4, G5 via an airreservoir unit 70 said a reservoir unit comprising one or more air reservoirs orairtanks.

According to an embodiment there is provided means 114 for determining thecurrent pressure and/or current pressure change rate provided in the airprocessing system 200. The means 114 may comprise any suitable meansfor determining the pressure and/or current pressure change rate such as apressure sensor unit. The electronic control unit 100 is operably connected tothe means 114 via a link L1. The electronic control unit 100 is arranged toreceive a signal from the means 114 representing data for pressure and/orpressure change rate provided in the air processing system 200. Theelectronic control unit 100 is arranged to process the pressure data from themeans 114 so as to determine whether compressed air distributed to theconsumers G1, G2, G3, G4, G5 is provided at a certain pressure level and/oror has a pressure change within a certain rate for operating the vehiclefunctions necessary for allowably operating the vehicle. According to an embodiment it is also provided a means for determining the current amountof air provided in the air processing system 200, not shown. The means fordetermining the current amount of air provided in the air processing system200 may be any suitable means such as one or more flow sensor units.

The electronic control unit 100 is operably connected to the respectiveconsumer G1-G5 via links L21, L22, L23, L24, L25, i.e. a link connected tothe respective consumer. lf it is determined that the pressure provided is below said certain pressurelevel and/or the amount of air provided is below said certain amount and/orthe pressure change is above said certain rate, the electronic control unit isarranged to send a signal via a link connected to the consumer/consumershaving vehicle function not necessary for allowably operating the vehicle, e.g.via the link L25, for disabling one or more vehicle functions so as to providepressure at said certain pressure level and/or amount of air at said certainamount and/or pressure change within said certain rate. According to anembodiment the electronic control unit can be arranged to send a signal via alink L2 to the air processing system 200, .e.g. to the multi circuit protectionvalve 50 for disabling one or more vehicle functions not necessary forallowably operating the vehicle so as to provide pressure at said certainpressure level and/or amount of air at said certain amount and/or pressurechange within said certain rate. Disabling one or more vehicle functions notnecessary for allowably operating the vehicle is performed in accordancewith a predetermined priority sequence. The predetermined priority sequencevehicle functions not necessary for allowably operating the vehicle isaccording to a variant performed such that the consumer/function ofconsumer with lowest priority is disabled first, e.g. the consumer G5, thiscontinuing until the certain pressure is obtained.

Fig. 5 schematically illustrates a hybrid vehicle fa with an electric drivemember 12 operating a compressor 20 connected to an air processingsystem 200 distributing compressed air to consumers G1, G2, G3, G4, G5 21 according to an embodiment of the present invention. The vehicle ta couldbe the vehicle 1 in fig. 1.

The hybrid vehicle comprises a powertrain 300. The powertrain 300comprises an electric motor arrangement 310 for driving the vehicle and acombustion engine 20 tor driving the vehicle. The electric motor arrangement310 comprises at least one electric machine 312. The electric motorarrangement 310 further comprises power electronics 314 for the electricmachine 312. The power electronics is configured to provide electric energyto the electric machine 312. The powertrain also comprises an energy source316 which according to an embodiment comprises a battery unit. The energysource 316 is configured to supply energy to the electric motor arrangement310 via the power electronics.

The powertrain 300 comprises an internal combustion engine 320 The powertrain 300 comprises a transmission unit 330 connected to a driveaxle X1 of the hybrid vehicle. The drive axle X1 is connected to groundengaging members which according to an embodiment are constituted by drive wheels.

The hybrid vehicle ta is driveable by means of the electric motorarrangement 310 and/or the combustion engine 320.

The electric motor arrangement 310 is connectable to the transmission unit330 via coupling means 10a.

The combustion engine 320 is connectable to the transmission unit 30 viacoupling means 320a.

The hybrid vehicle 1a comprises the electric drive member 10a for driving thecompressor 20. The electric drive member 10a comprises an electricmachine 12 and power electronics 14. 22 The electric drive member 10a is powered by means of the electric drivearrangement 310. The electric drive member 10a is powered by means of theenergy source 316, e.g. battery unit, of electric drive arrangement 310.

The electric drive arrangement 310, i.e. the energy source 316, e.g. batteryunit, of electric drive arrangement 310 is arranged to power other unitsnecessary and essential for vehicle operation 410, 420, 430.

Said other units 410, 420, 430 comprises according to an embodiment a 24 Vdc/dc converter 410. Said other units 410, 420, 430 comprises according toan embodiment a AG-compressor 420. Said other units 410, 420, 430comprises according to an embodiment one or more auxiliary units 430necessary for the vehicle. Such auxiliary units 430 may comprise an electricmachine necessary for operating e.g. a crane or the like and/or a garbagecompressor, and/or a cooling arrangement and/or other necessary auxiliaryunits.

The hybrid vehicle 1a comprises an air processing system 200. The electricdrive member 10a is configured to operate the compressor 20 for providingcompressed air for the air processing system 200. The air processing system200 is configured to supply compressed air to different air consumers G1, G2,G3, G4, G5 for different vehicle functions. The consumers comprise e.g.brake system G1 and air suspension system G2. The air processing system200 is configured to distribute the compressed air to different air consumersG1, G2, G3, G4, G5 via an air reservoir unit 70 said a reservoir unitcomprising one or more air reservoirs or air tanks.

The hybrid vehicle 1a comprises according to an embodiment means 114 fordetermining the current air pressure provided in the air processing system200. The means 114 may comprise any suitable means for determining thepressure such as one or more air pressure sensor units. Here the means 114for determining the current pressure and/or current pressure change rate provided in the air processing system 200 comprises an air pressure unit 23 114a arranged to sense the air pressure in the reservoir unit 70 and an airpressure unit 114b for sensing the air pressure within the air processingsystem 200. The electronic control unit 100 is operably connected to themeans 114 via a link L1. The electronic control unit 100 is arranged toreceive a signal from the means 114 representing provided in the airprocessing system 200. The electronic control unit 100 is arranged toprocess the pressure data from the means 114 so as to determine whethercompressed air distributed to the consumers G1, G2, G3, G4, G5 is providedat a certain pressure level and/or at a certain amount and/or has a pressurechange within a certain rate for operating the vehicle functions necessary forallowably operating the vehicle.

The hybrid vehicle 1a comprises according to an embodiment means fordetermining the current amount of air provided in the air processing system200, not shown. The means for determining the current amount of airprovided in the air processing system 200 may be any suitable means suchas one or more flow sensor units.

The hybrid vehicle 1a comprises an electronic control unit 100. ln fig. 5, theelectronic control unit 100 is arranged to control a number of systems, unitsetc. of the hybrid vehicle. The electronic control unit 100 may of course be aset of different control units 100 arranged to control different systems, unitsand the like of the hybrid vehicle 1a, where such a set of different electroniccontrol units may be operably connected or may be separated.

The electronic control unit 100 is operably connected to the electric motorarrangement 310. The electronic control unit 100 is arranged to control theelectric motor arrangement 310.

The electronic control unit 100 is operably connected to the internalcombustion engine 320. The electronic control unit is arranged to control theinternal combustion engine, said control according to an embodiment 24 comprising deactivating operation of the combustion engine such that thevehicle is driven solely by means of the electric motor arrangement 310.

The electronic control unit 100 is operably connected to the transmission unit330 for controlling the transmission unit.

The electronic control unit 100 is operably connected to the air processingsystem 200 for controlling the air processing system 200.

The electronic control unit 100 is operably connected to the electric drivemember 10a for controlling driving of the compressor 20.

The electronic control unit 100 is operably connected to the drive member10a. The electronic control unit 100 is arranged to determine malfunction ofthe electric drive member 10a. The electronic control unit 100 is arranged todetermine available power for the electric drive member.

The electronic control unit 100 is operably connected to one or more of theunits 410, 420, 430. The electronic control unit 100 is arranged to determinerequired power for units 410, 420, 430 so as to determine the availablepower for the electric drive member 10a.

The electronic control unit 100 is operably connected to the means 114 fordetermining current air pressure in the air processing system 200.

The electronic control unit 100 is operably connected to the air consumersG1-G5 for controlling the air consumers G1-G5.

The electronic control unit 100 is arranged to process the pressure data fromthe means 114 and data regarding operational status of the electric drivemember 10a comprising data regarding possible malfunction of the electricdrive member 10a and data regarding available power for the electric drivemember 10a so as to determine whether compressed air distributed to theconsumers G1, G2, G3, G4, G5 is provided at a certain pressure level and/or at a certain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehicle. lf it is determined that the pressure provided is below said certain pressurelevel and/or the amount of air provided is below said certain amount and/orthe pressure change is above said certain rate and/or if, the electronic controlunit 100 is arranged to send signal to one or more of the consumers C1-C5and/or to the air processing system 200 for disabling one or more vehiclefunctions not necessary for allowably operating the vehicle so as to providepressure at said certain pressure level and/or amount of air at said certainamount and/or pressure change within said certain rate. Disabling one ormore vehicle functions not necessary for allowably operating the vehicle isperformed in accordance with a predetermined priority sequence. Thepredetermined priority sequence vehicle functions not necessary forallowably operating the vehicle is according to a variant performed such thatthe consumer/function of consumer with lowest priority is disabled first, e.g.the consumer C5, this continuing until the certain pressure is obtained.

The electronic control unit 100 described above with reference to fig. 3-5 maybe one electronic control unit or more than one electronic control unit, e.g. a set of control units.

Fig. 6 schematically illustrates a block diagram of a method for controlling airsupply of a vehicle. The air processing system is configured to receivecompressed air distributed by means of a compressor operable by means ofa drive member. The air processing system is configured to distribute thecompressed air to different air consumers for different vehicle functions,certain vehicle functions being necessary for allowably operating the vehicle.

According to the embodiment the method for controlling air supply comprisesa step S1. ln this step it is determined, for a certain set of vehicle functions,whether compressed air distributed to the consumers is provided at a certain pressure level and/or at a certain amount and/or has a pressure change 26 within a certain rate for operating the vehicle functions necessary forallowably operating the vehicle.

According to the embodiment the method for controlling air supply comprisesa step S2. ln this step, if it is determined that the pressure provided is belowsaid certain pressure level and/or the amount of air provided is below saidcertain amount and/or the pressure change is above said certain rate, one ormore vehicle functions not necessary for allowably operating the vehicle aredisabled so as to provide pressure at said certain pressure level and/oramount of air at said certain amount and/or pressure change within said certain rate.

During normal operation when compressed air is distributed to different airconsumers for different vehicle functions, certain vehicle functions beingnecessary for allowably operating the vehicle, i.e. when compressed air isdistributed to a certain set of vehicle functions of consumers, the pressure ofthe compressed air distributed to the consumers is changing within a certainrange and within a certain rate. The air pressure may e.g. vary within a rangeof 9-12 bar. During normal operation of such pressure distribution the rate ofchange of the pressure will not exceed a certain level. Thus, the pressure willnot drop at a rate or speed exceeding a certain rate level/speed level. lf it is determined that the pressure change is above said certain rate, e.g. isdropping at a rate above said certain, it will result in the pressure dropping toa pressure level below a level for operating the vehicle functions necessaryfor allowably operating the vehicle. Thus, the term “for operating the vehiclefunctions necessary for allowably operating the vehicle” comprises operatingthe vehicle functions necessary for allowably operating the vehicle at acertain point of time after the determination. The term “for operating thevehicle functions necessary for allowably operating the vehicle” comprisescontinuously being able to operating the vehicle functions necessary forallowably operating the vehicle for a certain time. 27 Thus, if it is determined that the pressure change is above said certain rate,e.g. is dropping at a rate above said certain rate, the disabling of one or morevehicle functions not necessary for allowably operating the vehicle may bedone when the pressure level is within the normal pressure range such that itthereby can be avoided to reach a pressure level necessary for operatingallowably operating the vehicle. Reasons for compressed air distributed tothe consumers not being provided at a certain pressure level and/or at acertain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehiclemay comprise the compressor not being able provide maximum capacity, thisproblem generally occurring when the drive member for driving thecompressor being an electric drive member for electrically driving thecompressor. An electric drive member may advantageously be used for ahybrid vehicle or an electric vehicle. Reasons for the compressor not beingable to operate at maximum capacity may be due to malfunction of theelectric drive member, malfunction of the electric drive member being causedby e.g. too high temperature, low oil pressure, problems with powerelectronics/inverter such as power electronics/inverter becoming too hot.Reasons for the compressor not being able to operate at maximum capacitymay be due lack of available power/energy for the electric drive memberwhich may be due to low battery level, battery being too cold, battery beingtoo hot, power for operating the electric drive member not being sufficientdue to other units necessary and essential for vehicle operation such as 24 Vdc/dc converter, cooling liquid pump, auxiliary units necessary for the vehiclesuch as electric machine necessary for operating e.g. a crane or the like,garbage compressor, cooling arrangement or the like.

Reasons for compressed air distributed to the consumers not being providedat a certain pressure level and/or at a certain amount and/or has a pressurechange within a certain rate for operating the vehicle functions necessary forallowably operating the vehicle may comprise leakage in one or more circuitsfor consumers and/or too many consumers being used at the same time such 28 that maximum capacity of the Compressor is not sufficient to provide the certain pressure level.

According to an embodiment of the method the step of determining, for acertain set of vehicle functions, whether compressed air distributed to theconsumers is provided at a certain pressure level and/or at a certain amountand/or has a pressure change within a certain rate for operating the vehiclefunctions necessary for allowably operating the vehicle comprises the step of 29 determining the operational status of the Compressor so as to determine apossible pressure and/or amount of air to be provided by said compressor tosaid certain set of vehicle functions. Reasons for the compressor not beingable to operate at maximum capacity may be due to malfunction of theelectric drive member, malfunction of the electric drive member being causedby e.g. too high temperature, low oil pressure, problems with powerelectronics/inverter such as power electronics/inverter becoming too hot.Reasons for the compressor not being able to operate at maximum capacitymay be due lack of available power/energy for the electric drive memberwhich may be due to low battery level, battery being too cold, battery beingtoo hot, power for operating the electric drive member not being sufficientdue to other units necessary and essential for vehicle operation such as 24 Vdc/dc converter, cooling liquid pump, auxiliary units necessary for the vehiclesuch as electric machine necessary for operating e.g. a crane or the like,garbage compressor, cooling arrangement or the like.

With reference to figure 7, a diagram of an apparatus 500 is shown. Thecontrol unit 100 described with reference to fig. 3-5 may according to anembodiment comprise apparatus 500. Apparatus 500 comprises a non-volatile memory 520, a data processing device 510 and a read/write memory550. Non-volatile memory 520 has a first memory portion 530 wherein acomputer program, such as an operating system, is stored for controlling thefunction of apparatus 500. Further, apparatus 500 comprises a bus controller,a serial communication port, I/O-means, an A/D-converter, a time date entryand transmission unit, an event counter and an interrupt controller (not shown). Non-volatile memory 520 also has a second memory portion 540.

A computer program P is provided comprising routines for controlling airsupply of a vehicle. The air processing system is configured to receivecompressed air distributed by means of a compressor operable by means ofa drive member. The air processing system is configured to distribute thecompressed air to different air consumers for different vehicle functions,certain vehicle functions being necessary for allowably operating the vehicle.The program P comprises routines for determining the compressed airpressure in the respective air circuits. The program P comprises routines fordetermining, for a certain set of vehicle functions, whether compressed airdistributed to the consumers is provided at a certain pressure level and/or ata certain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehicle.The program P comprises routines for disabling one or more vehiclefunctions not necessary for allowably operating the vehicle, if it is determinedthat the pressure provided is below said certain pressure level and/or theamount of air provided is below said certain amount and/or the pressure 31 change is above said certain rate, so as to provide pressure at said certainpressure level and/or amount of air at said certain amount and/or pressurechange within said certain rate. The routines for disabling one or morevehicle functions not necessary for allowably operating the vehicle isperformed in accordance with a predetermined priority sequence. Theroutines for determining, for a certain set of vehicle functions, whethercompressed air distributed to the consumers is provided at a certain pressurelevel and/or at a certain amount and/or has a pressure change within acertain rate for operating the vehicle functions necessary for allowablyoperating the vehicle comprises routines for determining the current pressureand/or current pressure change rate provided in the air processing system.The routines for The computer program P may be stored in an executablemanner or in a compressed condition in a separate memory 560 and/or inread/write memory 550.

When it is stated that data processing device 510 performs a certain functionit should be understood that data processing device 510 performs a certainpart of the program which is stored in separate memory 560, or a certain partof the program which is stored in read/write memory 550.

Data processing device 510 may communicate with a data communicationsport 599 by means of a data bus 515. Non-volatile memory 520 is adaptedfor communication with data processing device 510 via a data bus 512.Separate memory 560 is adapted for communication with data processingdevice 510 via a data bus 511. Read/write memory 550 is adapted forcommunication with data processing device 510 via a data bus 514. To thedata communications port 599 e.g. the links connected to the control unit 100may be connected.

When data is received on data port 599 it is temporarily stored in secondmemory portion 540. When the received input data has been temporarilystored, data processing device 510 is set up to perform execution of code ina manner described above. The signals received on data port 599 can be 32 used by apparatus 500 determining, for a certain set of vehicle functions,whether compressed air distributed to the consumers is provided at a certainpressure level and/or at a certain amount and/or has a pressure changewithin a certain rate for operating the vehicle functions necessary forallowably operating the vehicle. The signals received on data port 599 can beused by apparatus 500 for disabling one or more vehicle functions notnecessary for allowably operating the vehicle, if it is determined that thepressure provided is below said certain pressure level and/or the amount ofair provided is below said certain amount and/or the pressure change isabove said certain rate, so as to provide pressure at said certain pressurelevel and/or amount of air at said certain amount and/or pressure changewithin said certain rate. The signals used by apparatus 500 for disabling oneor more vehicle functions not necessary for allowably operating the vehicle isperformed in accordance with a predetermined priority sequence. The signalsused by apparatus 500 for determining, for a certain set of vehicle functions,whether compressed air distributed to the consumers is provided at a certainpressure level and/or at a certain amount and/or has a pressure changewithin a certain rate for operating the vehicle functions necessary forallowably operating the vehicle comprises signals used by apparatus 500 fordetermining the operational status of the compressor so as to determine apossible pressure and/or amount of air to be provided by said compressor tosaid certain set of vehicle functions. The signals used by apparatus 500 fordetermining, for a certain set of vehicle functions, whether compressed airdistributed to the consumers is provided at a certain pressure level and/or ata certain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehiclecomprises signals used by apparatus 500 for determining the currentpressure and/or current pressure change rate provided in the air processingsystem.

Parts of the methods described herein can be performed by apparatus 500by means of data processing device 510 running the program stored in 33 separate memory 560 or read/write memory 550. When apparatus 500 runsthe program, parts of the methods described herein are executed.

The foregoing description of the preferred embodiments of the presentinvention has been provided for the purposes of illustration and description. ltis not intended to be exhaustive or to limit the invention to the precise formsdisclosed. Obviously, many modifications and variations will be apparent topractitioners skilled in the art. The embodiments were chosen and describedin order to best explain the principles of the invention and its practicalapplications, thereby enabling others skilled in the art to understand theinvention for various embodiments and with the various modifications as are suited to the particular use contemplated.

Claims

1. A method for controlling air supply of a vehicle (1; 1a), the air processingsystem (200) being configured to receive compressed air (A) distributed bymeans of a compressor (20) operable by means of a drive member (10), andconfigured to distribute the compressed air to different air consumers (G1,G2, G3, G4, G5) for different vehicle functions, certain vehicle functions beingnecessary for allowably operating the vehicle, characterized by the steps of:- determining, for a certain set of vehicle functions, whether compressedair distributed to the consumers (G1, G2, G3, G4, G5) is provided at a certainpressure level and/or at a certain amount and/or has a pressure changewithin a certain rate for operating the vehicle functions necessary forallowably operating the vehicle; and, - if it is determined that the pressure provided is below said certainpressure level and/or the amount of air provided is below said certain amountand/or the pressure change is above said certain rate, disabling one or morevehicle functions not necessary for allowably operating the vehicle so as toprovide pressure at said certain pressure level and/or amount of air at saidcertain amount and/or pressure change within said certain rate.

2. A method according to claim 1, wherein the step of disabling one or morevehicle functions not necessary for allowably operating the vehicle (1, 1a) isperformed in accordance with a predetermined priority sequence.

3. A method according to claim 1 or 2, wherein the step of determining, for acertain set of vehicle functions, whether compressed air distributed to theconsumers (G1, G2, G3, G4, G5) is provided at a certain pressure leveland/or at a certain amount and/or has a pressure change within a certain ratefor operating the vehicle functions necessary for allowably operating thevehicle comprises the step of determining the operational status of thecompressor (10) so as to determine a possible pressure and/or amount of airto be provided by said compressor to said certain set of vehicle functions.

4. A method according to any of claims 1-3, wherein the step ofdetermining, for a certain set of vehicle functions, whether compressed airdistributed to the consumers is provided at a certain pressure level and/or ata certain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehiclecomprises the step of determining the current pressure and/or current pressure change rate provided in the air processing system.

5. A method according to any of claims 1-4, wherein said drive member (10)is an electric drive member (10a) for electrically driving the compressor (20).

6. A method according to any of claims 1-4, wherein said drive member (10)is an internal combustion engine (1 Ob).

7. A system (I) for controlling air supply of a vehicle (1; 1a), an airprocessing system (200) being configured to receive compressed air (A)distributed by means of a compressor (20) operable by means of a drivemember (10), and configured to distribute the compressed air to different airconsumers (G1, G2, G3, G4, G5) for different vehicle functions, certainvehicle functions being necessary for allowably operating the vehicle,characterized by means (110) for determining, for a certain set of vehiclefunctions, whether compressed air distributed to the consumers (G1, G2, G3,G4, G5) is provided at a certain pressure level and/or at a certain amountand/or has a pressure change within a certain rate for operating the vehiclefunctions necessary for allowably operating the vehicle (1; 1a); and means(120) for disabling one or more vehicle functions not necessary for allowablyoperating the vehicle if it is determined that the pressure provided is belowsaid certain pressure level and/or the amount of air provided is below saidcertain amount and/or the pressure change is above said certain rate so asto provide pressure at said certain pressure level and/or amount of air at saidcertain amount and/or pressure change within said certain rate. 36

8. A system according to claim 7, wherein the means (120) for disabling oneor more vehicle functions not necessary for allowably operating the vehicle(1 ; ta) comprises means (122) for performing said disabling in accordancewith a predetermined priority sequence.

9. A system according to claim 7 or 8, wherein the means (110) fordetermining, for a certain set of vehicle functions, whether compressed airdistributed to the consumers is provided at a certain pressure level and/or ata certain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehiclecomprises means (112) for determining the operational status of thecompressor so as to determine a possible pressure and/or amount of air tobe provided by said compressor to said certain set of vehicle functions.

10. A system according to any of claims 7-9, wherein the means (110) fordetermining, for a certain set of vehicle functions, whether compressed airdistributed to the consumers is provided at a certain pressure level and/or ata certain amount and/or has a pressure change within a certain rate foroperating the vehicle functions necessary for allowably operating the vehiclecomprises means (114) for determining the current pressure and/or current pressure change rate provided in the air processing system.

11. A system according to any of claims 7-10, wherein said drive member(10) is an electric drive member (10a) for electrically driving the compressor(20).

12. A system according to any of claims 7-10, wherein said drive member (10) is an internal combustion engine.

13. A vehicle (1) comprising a system (I) according to any of claims 7-12.

14. A computer program (P) for controlling an air pressure system (200), saidcomputer program (P) comprising program code which, when run on anelectronic control unit (100) or another computer (500) connected to the 37 electronic control unit (100), causes the electronic control unit to perform the steps according to claim 1-6.

15. A computer program product comprising a digital storage medium storingthe computer program according to claim 14.