`Volkswagen Group of America, Inc. - Petitioner
`
`1
`
`
`
`‘Central classification and?
`"criteria-establishment
`
`Driving strategy
`selection
`
`Non—central control
`units
`
`Assemblies‘
`
`2
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`.Convext accelerator pedal/brake
`into desired wheel torque (block 12)
`include driv-in ~-
`
`Interrogate information channel '(b1ock_ 5)
`
`‘
`
`Select primary dI'iViJ18 5“3‘°8Y (block 6)
`
`Choose basic operating "parameters
`for drive train (block 7):
`Drive/deceleration souxce, mlculation of
`working points of drive/deceleration source,
`calculation of working point of gear unit
`
`Monitor driving stability: ABS system, drive-slip control
`TCS and driving-stability control FSR,
`set desired bralcin to
`
`(‘block 7 or 9)
`
`coiwec: drive/brakzin-g torqfic
`‘ inthe drive('b1ock7or 9)
`’
`
`_'Inc.-ease driving power
`
`5
`
`
`
`Calculate steady-state
`paramctcrs of drive/gear unit
`(based on performance characteristics,
`algorithm, fuzzy system, stratcgy
`._¥iv'*1=*=i_9==)
`
`Calculate temporary action on
`drive/gear unit (as a function
`of driving situation. driving manoeuvres) "
`
`for example, if kcpt in same gear in thrust opeflfion. W533 355i5‘3‘1°‘
`
`6
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`
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`-1-
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`2318105
`
`DRIVE TRAIN CONTROL FOR A MOTOR VEHICLE
`
`The invention relates to a drive train control for
`
`a motor vehicle in which the position of the
`
`accelerator pedal is used to calculate desired values
`
`for the engine and gear unit of the motor vehicle, and
`
`to a motor vehicle utilising such a drive train
`control.
`
`In known arrangements,
`
`the control systems for the
`
`engine,
`
`the gear unit and the sub-assemblies of a motor
`
`vehicle operate largely on their own,
`
`that is,
`
`the
`
`working point and the operating mode of each controlled
`
`assembly is set largely independently.
`
`Individual
`
`component parts of the drive train of a motor vehicle
`
`are able to communicate via, for example, a CAN-bus,
`
`although these are predominantly used just to exchange
`
`sensor data by means of multiplexing. Moreover,
`
`the
`
`individual control systems influence each other by
`
`communicating during certain procedures, for example by
`
`reducing the engine torque when changing the
`
`transmission ratio of the gear unit in order to improve
`
`the ease of changing gear; by engine drag torque
`
`control when braking; and by a braking action or an
`
`engine torque reduction when drive slip occurs.
`
`One known proposal for system networking in the
`
`automobile aims to achieve an integrated drive train
`
`control for a motor vehicle, by means of which drive
`
`train control the position of the accelerator pedal is
`
`interpreted as a wheel torque that is desired by the
`
`driver and is used to calculate desired values for the
`
`engine and for the gear unit of the motor vehicle
`
`(F & M Feinwerktechnik Mikrotechnik Messtechnik
`
`101(1993)3, pages 87 to 90).
`
`The objective of higher-
`
`level optimization of the engine control, electronic
`
`accelerator pedal and gear-unit control subsystems that
`
`is proposed in that document is to reduce the fuel
`
`consumption and to improve the drivability of the motor
`
`7
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`
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`-2-
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`vehicle,
`
`in particular in so far as spontaneous
`
`reaction to accelerator pedal movements is concerned.
`
`The invention seeks to improve the overall
`
`operation of a motor vehicle. Thus,
`
`in a described
`
`embodiment of the invention the emissions
`
`(hydrocarbons, nitrogen oxides etc.) are minimized by
`
`centrally determining a strategy for the engine
`
`control,
`
`the engine—output regulating unit and the
`
`gear-unit control such that the discharge of harmful
`
`substances,
`
`in particular in an urban area,
`
`is
`
`minimized.
`
`The central strategy can also be determined
`
`by a driving performance-orientated mode of the motor
`
`vehicle.
`
`In this strategy all the non—central
`
`functional units are configured in such a way that
`
`optimum acceleration and rapid response of the drive to
`
`the driver's wishes is possible.
`
`Such a mode is
`
`necessary for sports-style driving and when driving
`
`uphill.
`
`According to the present invention,
`
`there is
`
`provided a drive train control for a motor vehicle,
`
`comprising
`
`a classification device which evaluates sensor
`
`signals from the drive train and which classifies
`
`operating parameters of the motor vehicle, and
`a calculating device which receives sensor signal
`
`indicating positions of the accelerator pedal and the
`brake pedal, and which produces from the sensor signals
`and the classified operating parameters central control
`
`parameters for drive sources and decelerating units of
`the drive train.
`
`For a better understanding of the present
`
`invention, and to show how it may be brought into
`
`effect, reference will now be made, by way of example,
`
`to the accompanying drawings,
`
`in which:
`
`Figure 1 shows a block diagram representing the
`hierarchical structure or architecture of an integrated
`
`8
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`
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`-3-
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`drive train control in accordance with one embodiment
`
`of the invention;
`
`Figure 2 shows an integrated drive train control
`
`in accordance with one embodiment of the invention;
`
`Figure 3 shows the control of the engine and of
`
`the gear unit of another embodiment of the drive train
`
`control according to the invention;
`
`Figure 4 is a flow chart of the program which is
`
`executed by the drive train control according to Figure
`
`2; and
`
`Figure 5 illustrates a sub—program of the flow
`
`chart of Figure 4.
`
`An integrated drive train control 1 has the
`
`component parts as shown in Figure 1.
`
`The component parts are: sensors 1.01, which have
`
`been symbolically combined to form a block; a central
`
`classification and criteria—establishing block 1.02; a
`
`central operating parameter—obtaining block 1.03 to
`
`which signals from the accelerator pedal and the brake
`
`pedal of the motor vehicle are fed; a driving strategy
`
`selection block 1.04; non—central control units 1.05,
`
`combined to form a block; and the assemblies of the
`
`drive train 1.06, for example the engine,
`
`the gear unit
`
`and the brakes of the motor vehicle, which are to be
`
`controlled.
`
`The function and mode of operation of the
`
`component parts of Figure 1 are explained in
`
`conjunction with the description of the further
`
`Figures.
`
`The integrated drive train control 1 is
`
`represented in greater detail in Figure 2.
`
`It has the
`
`following component parts of the central classification
`
`and criteria-establishing block 1.02: a driver—type and
`
`driver request-obtaining circuit arrangement 2; an
`
`environment and road-type localization circuit
`
`arrangement 3
`
`(for example by way of a GPS); a driving
`
`9
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`
`
`-4-
`
`manoeuvre and driving situation identifying circuit
`
`arrangement 4; and an information channel 5 (for
`
`example a radio telephone or a satellite receiver).
`
`The signals from various sensors in the motor vehicle,
`
`which are symbolically denoted by S, are supplied by
`
`way of corresponding signal lines to the circuit
`
`arrangements 2 to 5 and further circuit component parts
`
`of the drive train control 1 (still to be described).
`
`The signal lines are indicated in the drawing as
`
`multiple lines, yet can also be realized as a data bus
`
`(for example a CAN-bus).
`
`A primary driving strategy selection block 6
`
`receives output signals of the circuit arrangements 2
`
`to 5 mentioned above via lines 14 to 18.
`
`A wheel
`
`torque calculating device 12 receives signals from a
`
`brake pedal 20 and an accelerator pedal 21 and provides
`
`its output to the primary driving strategy selection
`
`block 6 through line 19.
`
`Output signals of the primary driving strategy
`
`selection block 6 are supplied to a basic operating
`
`parameter—obtaining block 7 and an electronic engine
`control and engine-output regulating unit 9. Output
`
`signals of the basic operating parameter—obtaining
`
`block 7 are supplied to: a driver information or
`
`display unit 16; an electrical power-assisted steering
`unit
`(EPAS) 8; an electronic engine control and engine-
`
`(EMS/ETC) 9; an electronic gear
`output regulating unit
`unit control
`(EGS) 10; and a brake control 11, which
`
`can include an ABS system, a drive-slip control TCS and
`
`a driving-stability control FSR.
`
`The basic operating parameter-obtaining block 7
`
`now calculates the central operating parameters of the
`
`whole drive train in a coordinated manner in accordance
`
`with the strategy stipulation from block 6.
`
`For
`
`transmission ratios and the desired engine
`example,
`torque are determined in block 7, as are the drive type
`
`10
`
`
`
`-5-
`
`and in the case of a hybrid drive,
`
`the individual
`
`operating points of the drive. More extensive control
`
`of the engine and gear unit than had previously been
`
`possible is thus achieved.
`
`The engine torque can thus
`
`be set as a function of the transmission ratio. This
`
`increases the drivability of the motor vehicle, since
`
`the driver no longer needs to compensate for the loss
`
`of output torque when there is a change up to a higher
`
`gear.
`
`In addition, however, emissions of harmful
`
`substances can also be reduced in an effective manner,
`as explained below.
`
`The coordinated determination of the operating
`
`parameters of the engine and the gear unit occurs not
`
`only during a steady state,
`
`that is, not only when
`
`there is a request for a constant wheel torque from
`
`block 12, but information on dynamic processes, such
`
`as, for example, cornering or a transition into overrun
`
`operation (vehicle speed is thereby reduced), may be
`
`also taken into consideration by block 7 in order to
`
`coordinate the subordinate functional units 8-11.
`
`Thus
`
`during an overrun it is possible not only to keep the
`
`current gear ratio, but also at the same time to
`
`activate the fuel cut—off on overrun. When there is
`
`extreme cornering,
`
`in order to maintain driving
`
`stability it is expedient to fix the transmission ratio
`
`(-> EGS [electronic gear unit control]) and attenuate
`
`load changes in the drive or allow them to occur more
`
`slowly (-> EMS/ETC [electronic engine control and
`
`engine-output regulating unit]).
`
`Centralization for the purposes of drivability and
`
`emission management is, however, only to be effected as
`
`far as necessary (strategy stipulation or delegation).
`All the other functions occur as far as possible in an
`
`independent manner within the non-central control units
`
`(for example functions for driving stability).
`
`The control circuits or gear units 8 to 11 produce
`
`11
`
`
`
`-5-
`
`actuating signals with which the individual assemblies
`
`or component parts of the drive train 24 of the motor
`
`vehicle are controlled,
`
`that is,
`
`the engine by its
`
`throttle valve,
`
`the gear unit and the brakes of the
`
`motor vehicle.
`
`The actuating signals are fed by way of
`
`lines A from the circuit arrangements 9 to 11 to the
`
`assemblies of the drive train, sensor signals S being
`
`fed by way of corresponding lines to said circuit
`
`arrangements.
`
`The control circuit arrangements or gear
`
`units 8 to 11 can of course also be assembled as so-
`
`called in-situ units together with the respective
`
`assembly which is to be controlled or can be integrated
`
`therein.
`
`Thus it is expedient, for example,
`
`to combine
`
`the control 11,
`
`in the case of an electrical brake
`
`actuator, with the brake actuator.
`
`The control
`
`function is not changed in this way.
`
`The individual component parts of the drive train
`
`itself are diagrammatically represented at the bottom
`
`of Figure 2;
`
`they are not explained here in greater
`
`detail, since they are generally known.
`
`In a hybrid
`
`drive — that is, an internal combustion engine combined
`
`with an electric motor —
`
`the engine is coupled with the
`
`electric motor and a generator G.
`
`Such a hybrid drive
`
`is known, for example,
`
`from VDI-Report No. 1225, 1995,
`
`pages 281-297.
`
`Examples of an overall or combined drive train control
`
`according to the invention are:
`
`1.
`
`-
`
`Operation with minimum emissions (HC, NOx):
`
`The primary driving strategy selection block 6
`
`commits the mode of operation of the whole drive
`
`train to minimum harmful substance discharge.
`
`A central "decision—making unit",
`
`that is,
`
`the
`
`1 basic operation-parameter obtaining block 7,
`
`in
`
`accordance with this stipulation calculates the
`
`essential operating parameters of the circuit
`
`arrangements 9, 10 (EMS [electronic engine
`
`12
`
`
`
`-7-
`
`control], ETC [engine-output regulating unit], EGS
`
`[electronic gear unit control])
`
`in such a way that
`
`the discharge of harmful substances is minimized
`
`(for example in urban areas). This stipulation
`
`can be translated by the subordinate functional
`
`units in the following manner:
`
`——
`
`ETC (electronic engine-output control):
`
`load
`
`changes of the internal combustion engine
`
`(requested by unit 12) are attenuated or the
`
`operating range is limited.
`
`By avoiding non-
`
`steady state processes, regulations and
`
`controls aimed at reducing emissions can then
`
`operate faultlessly. Operating ranges having
`
`a quantitatively or qualitatively undesirable
`
`emission composition are avoided.
`
`EMS (electronic engine control):
`
`activation
`
`of a mode with low emission levels, for
`
`example reduction of the acceleration
`
`enrichment in the case of an internal
`
`combustion engine, or
`
`— changes in the drive type (for example to
`
`electric motor, or hydrogen drive)
`
`EGS (electronic gear unit control): effects,
`
`in the case of the internal combustion
`
`engine, an operation that is as steady-state
`
`as possible in the range with minimum
`
`emission levels, for example using CVT or a
`
`multi-stage gear unit;
`
`—
`
`adaptation of the gearing when the drive
`
`type (for example electric motor, hydrogen
`
`drive)
`
`is changed. Particularly for this
`
`function good cooperation between the engine
`
`and the gear unit is important, because a
`
`plurality of combinations of the resultant
`
`engine torque and transmission ratio are
`
`possible for a given requested acceleration/
`
`13
`
`
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`-3-
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`speed combination.
`
`In addition, it is
`
`necessary to coordinate the characteristics
`
`of the change of the two manipulated
`
`variables over time.
`
`Driving performance-orientated mode:
`
`In an operation that is analogous to the operation
`
`with minimum emissions, all the non-central
`
`functional units are set in such a way that
`
`optimum acceleration and rapid response of the
`
`drive to a driver-request (unrestricted drive
`
`type), which are necessary for sports-style
`
`driving or driving uphill, are available.
`
`The architecture of such function sharing can be
`
`seen in Figure 1. Of course, decisions of lower
`
`control planes, which affect higher—level stipulations,
`
`are signalled to the higher control planes if
`
`necessary. This will, however, be explained further
`
`with reference to Figure 2,
`
`the functioning of which
`
`will now be explained in detail.
`
`Circuit arrangement 2 is used to obtain
`
`information on the type of driver,
`
`that is, a
`
`classification between driving performance-orientated
`
`mode and economical mode.
`
`An example of such a
`
`function is described in EP 0 576 703 A1.
`
`A signal
`
`characterising the driver's style of driving is fed to
`
`a primary driving strategy selection block 6 by way of
`
`a line 14.
`
`Block 3 determines the type of road
`
`(town/motorway/country).
`
`It may also be provided with
`
`additional sensors, for example,
`
`to ascertain the
`
`general degree of air pollution.
`
`If the local position
`
`of the vehicle is known with a Global Positioning
`
`System (GPS)
`
`in conjunction with a digital map (on CD-
`
`ROM),
`
`this information on the local air pollution can
`
`be made available to block 6.
`
`Detection of individual driving manoeuvres, such
`
`14
`
`
`
`-9-
`
`as, for example, cornering,
`
`roadway ascent, drive-brake
`
`slip, carried out in block 4, and also information on
`
`longitudinal and lateral stability can also be used to
`
`determine the driving strategy selection. This
`
`information can also be made available to block 7 in
`
`order, by way of the medium-term operating strategy,
`
`to
`
`achieve a suitable mode of operation of the drive train
`
`in the short term as well.
`
`It is also possible for
`
`this information for blocks 6 and 7 to originate from
`
`non-central control units (for example information on
`
`stability, with respect to vehicle movement dynamics,
`
`from the ABS/TCS/FSR control unit 11 [ABS system,
`
`drive-slip control TCS and driving—stability control
`
`FSR]) or from the information channel 5. This block 5
`
`makes information available that is given by a central
`
`"control system", for example by a traffic-monitoring
`
`authority. Thus it is possible to direct a low
`
`emission level mode of operation centrally in a region.
`
`Block 6 is used to determine the primary driving
`
`strategy selection for the subordinate unit 7 which in
`
`turn determines the central operating parameters for
`
`the non-central control units in a coordinated manner.
`
`The information on lines 14, 15, 17 and 18 is compared
`
`by means of an established control principle. This is
`
`realized by means of a fuzzy system, mathematically
`
`formulated algorithms or a neural network.
`
`The sensors S supply necessary signals both for
`
`the establishment of the classification and the
`
`criteria in the uppermost layer of the drive train
`
`control 1,
`
`that is,
`
`in units 2 - 5, and also for the
`
`non-central control units for the individual
`
`assemblies. Localization of the sensors with regard to
`
`the functional blocks plays a subordinate role provided
`
`that communication between the sensor signal processing
`
`unit in the respective control unit
`
`(ECU) and the
`
`information source is guaranteed.
`
`It is also not
`
`15
`
`
`
`-10-
`
`important, with regard to the functional architecture,
`
`which functional units are physically present and
`
`combined in which ECU.
`
`It is thus by all means
`
`possible to integrate the driver-type and driver-
`
`request obtaining circuit arrangement 2 in the gear
`
`unit control
`
`(EGS) 10, whilst environment and road-type
`
`classifications can be accommodated in block 11
`
`(longitudinal and lateral dynamic control).
`
`It is also possible for a central computer to
`
`include units 12, 6, 7.
`
`The virtual architecture, as
`
`represented in Figure 2, is what is essential in order
`
`to achieve functioning which is altogether improved.
`
`Communication between the physical units,
`
`advantageously realized as a form of high-speed serial
`
`bus communication (for example by way of a CAN—bus),
`
`plays an important r6le thereby.
`
`The stipulations of the driver by means of the
`
`accelerator pedal are converted,
`
`in block 12,
`
`into a
`
`desired wheel torque stipulation,
`
`that is,
`
`into the
`
`torque which is to be transmitted from the driving
`
`wheels to the roadway.
`
`The influence of environmental
`
`influences, such as additional road resistance (uphill
`
`drive,
`
`loading),
`
`is not to be taken into consideration
`
`here so as not to alienate the driver from physical
`
`reality.
`
`Block 12 is represented separately in Figure 2,
`
`yet can also be physically accommodated in the non-
`central control units 8-11 or 16 (for example EMS-ETC
`
`[electronic engine control and engine-output control]).
`
`The same applies to blocks 1-7.
`
`The signal on line 19
`
`can be output as a desired wheel torque or even as a
`
`desired circumferential wheel force or desired initial
`
`It is also possible to stipulate negative
`gear torque.
`desired wheel torques or circumferential forces due to
`
`the continuous information provided at the brake pedal
`
`20. Thus,
`
`integrated management of driving units (for
`
`16
`
`
`
`-11-
`
`example internal combustion engine, electric motor,
`
`rotating flywheel) or decelerating units which consume
`
`energy (for example service brake, current generator,
`
`static flywheel)
`
`is possible. As an alternative to the
`
`wheel—torque stipulation made by the driver, it is also
`
`possible for this to be made by a driving speed
`
`regulator or control 23 (FGR).
`
`The information channels between the “basic
`
`operating parameter-obtaining" block 7 and the units 9,
`
`10 and 11 can be used in a bidirectional manner.
`
`The
`
`reason for this is the need, when calculating the basic
`
`operating parameters, not only to take into account
`
`external conditions, such as driver type, environment
`
`and driving manoeuvres, but also to take internal
`
`preset operating states of the controlled units in the
`
`drive into consideration as well.
`
`For example, it is
`
`important, after a cold start,
`
`to operate the internal
`
`combustion engine at increased speeds in order to
`
`assist in the heating of the catalytic converter.
`
`Moreover, additional heat sources (for example an
`
`electrically heated catalytic converter) present an
`
`additional load on the engine drive. Delayed
`
`adjustment of the ignition after the cold start
`
`(possibly an injection of secondary air) for the same
`
`purpose changes the characteristics of the drive,
`
`something which must be taken into consideration by
`
`unit 7 (for example by shifting gear shift points to
`
`higher engine speeds).
`
`Similarly, a certain operating state in the gear
`
`unit can affect the calculation of the transmission
`
`ratio of the gear unit (for example cold gear oil when
`
`switching on the converter bypass;
`
`in the case of
`
`excess temperature of the gear unit, shifting the
`
`engine speeds into ranges which increase the volume
`
`throughput of the oil pump of the gear unit through the
`
`oil cooler is expedient). Other actions affecting the
`
`17
`
`
`
`-12-
`
`engine torque, such as, for example, an increase in
`
`order to compensate for the torque loss on account of
`
`the air-conditioning compressor or efficiency losses of
`
`the gear unit
`
`(CVT: adjustment of the transmission
`
`ratio necessitates greater pumping capacity),
`
`take
`
`place in the control plane represented by blocks 8-11
`
`provided that they do not need to be assisted by
`
`measures in block 7 as well.
`
`In the drive train control according to the
`
`invention not only is the gear-changing behaviour when
`
`driving uphill and downhill or when there is a driving-
`
`performance request related to a driving style and
`
`situation subject to criteria different from the usual
`
`criteria, but so too is the control of the whole drive
`
`train including drive sources.
`
`It can therefore be expedient and necessary in
`
`critical situations and during driving manoeuvres to
`
`adapt or to keep the current transmission ratio so that
`
`it is related to the situation,
`
`irrespective of the
`
`Such
`general strategy which has just been established.
`dynamic corrections are functionally combined with the
`control of the engine in the control concept according
`
`to the invention (one example is keeping in the same
`
`gear and activating the engine fuel cut—off on overrun
`
`in a coordinated manner).
`
`It is expedient still not to include any
`
`parameters which are specific to the engine in block 12
`(wheel torque calculation), since after all, for
`
`in the case of a hybrid drive the choice of
`example,
`drive type is not yet certain on this decision plane.
`Of course, it is useful to include parameters relating
`
`to the conditions, such as traction relationships
`
`(winter operation, split subsoil) and ultimately,
`
`in
`
`the case of powerful motorized vehicles,
`
`to reduce the
`
`sensitivity of the system somewhat preventively (given
`
`the same accelerator pedal produce less wheel torque).
`
`18
`
`
`
`-13-
`
`In general, conversion of the accelerator pedal
`
`position into a wheel torque can be effected by means
`
`of a fuzzy system which combines the multiple
`
`dependencies to give one desired wheel torque.
`
`The advantages of the invention also lie in
`
`integrated wheel torque management which also processes
`
`the wheel torque as a negative value and influences
`
`units decelerating both the drive sources and the
`
`vehicle.
`
`It is particularly simple in this connection
`
`to bring about coupling with brake systems with
`
`electrical brake application ("brake by wire").
`
`Not only the transmission ratios and the
`
`respective desired engine torque, but also the drive
`
`type and the individual operating points thereof are
`
`established in block 7.
`
`In this connection, not only
`
`is operation that is strictly wheel torque—orientated
`
`possible in accordance with the driver's stipulation,
`
`but the real wheel torque can also be influenced or
`
`limited by means of central stipulations relating to
`
`the emission of harmful substances. Of course, such
`
`actions must be indicated to the driver by block 16
`
`and, as far as possible,
`
`take place without restricting
`
`drivability.
`
`Blocks 2 to 7, 12 and 16 can be accommodated in
`
`independent physical units (control units) or be
`
`integrated in units 8-11. This flexibility constitutes
`
`a further advantage of the invention.
`
`The data exchange between the individual control
`
`units is advantageously effected in a torque—based
`
`manner.
`
`The following is to be understood by the term
`
`"torque—based":
`
`if, for example,
`
`the gear unit
`
`requests an engine torque reduction, it transmits to
`
`the engine control a variable which represents the
`
`desired torque,
`
`that is,
`
`the desired engine torque, and
`
`does not demand, for example, a reduction of the
`
`ignition angle by 5%. Conversely,
`
`in order to
`
`19
`
`
`
`-14-
`
`determine the engine torque at the current working
`
`point for example,
`
`the throttle valve position and the
`
`engine speed,
`
`from which the gear—unit control could
`
`determine the current engine torque by way of a matrix
`
`stored in the gear—unit control, are not transmitted to
`
`the gear-unit control, but instead the engine control
`
`transmits the current engine torque to the gear-unit
`
`control by way of an interface (for example, a CAN-
`
`bus).
`
`A somewhat simplified integrated drive train
`
`control 1, which is used to control an internal
`
`combustion engine and a gear unit, can be seen in
`
`The individual reference symbols correspond
`Figure 3.
`to those of Figure 2, but are provided with a "*" for
`
`the purposes of distinction.
`
`The function of this
`
`drive train control corresponds to that described
`
`above,
`
`in so far as the respective component parts are
`
`present.
`
`A flow chart, which is worked through by the drive
`
`train control 1 according to the invention, can be seen
`
`in Figures 4 and 5. After the start A the program
`
`carries out the following steps S1 to S11:
`
`S1:
`
`If desired,
`
`the driving speed control FGR is
`
`activated.
`
`S2:
`
`Information from the accelerator pedal or the
`
`brake pedal is converted into a desired wheel
`
`torque (block 12).
`
`The driving speed control is
`
`included therein, if applicable.
`
`The driver,
`
`the environment and the driving
`
`manoeuvres are classified or detected (in blocks
`
`1,
`
`3 and 4).
`
`The information channel 5 is interrogated (in
`
`block 6).
`
`A primary driving strategy is selected in block 6.
`
`The basic operating parameters are selected for
`
`the drive train (in block 7):
`
`the drive or
`
`20
`
`
`
`-15-
`
`deceleration source,
`
`the calculation of the
`
`working points of the drive and of the
`
`deceleration sources,
`
`the calculation of the
`
`working point of the gear unit
`
`(in block 7).
`
`The driving stability is monitored: with ABS,
`
`engine-output regulating unit TCS and driving
`
`stability control FSR.
`is set.
`
`The desired braking torque
`
`It is determined whether action with respect to
`
`driving stability should be effected (in block 7
`
`or 9).
`
`If so,
`
`in
`
`the driving or braking torque in the drive is
`
`corrected (block 7 or 9).
`
`If not,
`
`in step
`
`it is determined whether there is efficiency loss
`
`in the drive.
`
`If so,
`
`in step
`
`the driving power is increased. Subsequently and
`
`also if the determination is "no",
`
`the program
`
`reaches its
`
`End.
`
`Step S6 can also be carried out as a sub-program
`
`with the following steps (Figure 5):
`
`S6.1:
`
`The steady-state parameters of the drive and
`
`of the gear unit are calculated (based on
`
`performance characteristics, on an algorithm,
`
`on a fuzzy system or on a strategy
`
`stipulation).
`
`Calculations are made with regard to
`
`temporary action on the drive and the gear
`
`unit,
`
`that is, as a function of the driving
`
`situation and the driving manoeuvres, for
`
`example if kept in the same gear in thrust
`
`operation or if there is braking assistance.
`
`The program is subsequently executed as explained
`
`with reference to Figure 4 until its end.
`
`21
`
`
`
`CLAIMS
`
`1.
`
`A drive train control for a motor vehicle,
`
`comprising
`
`a classification device which evaluates sensor
`
`signals from the drive train and which classifies
`
`operating parameters of the motor vehicle, and
`
`a calculating device which receives sensor signals
`
`indicating positions of the accelerator pedal and the
`
`brake pedal, and which produces from the sensor signals
`
`and the classified operating parameters central control
`
`parameters for drive sources and decelerating units of
`
`the drive train.
`
`2.
`
`A drive train control as claimed in claim 1,
`
`wherein the transmission ratio is set by the
`
`calculating device.
`
`3.
`
`A drive train control as claimed in
`
`or 2, wherein the engine torque is set by the
`
`calculating device.
`
`4.
`
`A drive train control as claimed in any
`
`preceding claim, wherein the type of drive source is
`
`determined by the calculating device.
`
`5.
`
`A drive train control as claimed in claim 4,
`
`wherein a hybrid drive is determined by the calculating
`
`device and individual operating points of this hybrid
`
`drive are set by the calculating device.
`
`6.
`
`A drive train control as claimed in claim 5,
`
`wherein the engine torque is set by the calculating
`
`device as a function of the transmission ratio of the
`
`hybrid drive.
`
`7.
`
`A drive train control as claimed in any
`
`preceding claim, further comprising a selection circuit
`
`arrangement, for selection, with the aid of output
`signals of the classification circuit arrangement, of a
`driving strategy, and non-central control units, which
`
`receive output signals of the calculating device and
`
`the selection circuit arrangement, and which produces
`
`22
`
`
`
`-17-
`
`the control signals for the engine,
`
`the gear unit and
`
`the brake system of the motor vehicle.
`
`8.
`
`A drive train control means as claimed in
`
`claim 7, wherein the data exchange between the
`
`individual control units is effected in a torque-based
`manner.
`
`9.
`
`A drive train control means substantially as
`
`herein described, with reference to the accompanying
`
`drawings.
`
`10.
`
`A motor vehicle incorporating a drive train
`
`control means as claimed in any preceding claim.
`
`23
`
`
`
`P The
`Oflice
`
`'8
`
`Application No:
`Claims searched:
`
`GB 9719404.7
`1 - 8
`
`Examiner:
`Date of search:
`
`Tom Sutherland
`5 February 1998
`
`Patents Act 1977
`
`Search Report under Section 17
`
`Databases searched:
`
`UK Patent Office collections, including GB, EP, W0 & US patent specifications, in:
`
`UK Cl (Ed.P): B7H (HXG); F2D (DA)
`
`Int Cl (Ed.6): B60K 41/20, 41/26, 41/28
`
`Other:
`
`Documents considered to be relevant:
`
`Category Identity of document and relevant passage
`
`GB 2255057 A
`
`(FUJI) Note Fig. 6.
`
`GB 2240827 A
`
`(FUJI) Note Figs 3, 5, 6.
`
`Relewm
`to claims
`
`1 — 3, 7
`
`EP 0388107 A
`
`(HITACHI) Whole document relevant, note Figs
`21, 26, 36.
`
`WO 90/03898 A
`
`(LANG) See claims 1, 2 and 5.
`
`US 5450324
`
`(FORD) Whole document.
`
`US 5351776
`
`(BOSCH) Whole document but note col. 5 lines 31,
`61, 62, col. 6 line 8, claim 1.
`
`US 4853720
`
`(HITACHI) See Figs 1 to 4.
`
`Document indicating lack of novelty or inventive step
`Document indicating lack of inventive step if combined
`with one or more other documents of same category.
`
`Member of the same patent family
`
`A Document indicating technological background and/or state of the art.
`P Document published on or after the declared priority date but before
`the filing date of this invention.
`E Patent document published on or after, but with priority date earlier
`than. the filing date of this application.
`
`An Executive Agency of the Department of Trade and Industry
`
`24