SE543885C2

SE543885C2 - Method and arrangement for controlling a vehicle powertrain with a power take-off during gearshift

Info

Publication number: SE543885C2
Application number: SE2050070A
Authority: SE
Inventors: Jörgen Engström; Jonas Udd; Marcus Engman; Mikael Bergquist; Susanna Jacobsson
Original assignee: Scania Cv Ab
Priority date: 2020-01-27
Filing date: 2020-01-27
Publication date: 2021-09-14
Also published as: SE2050070A1; DE102020133759A1

Abstract

A control device (100) and a method for controlling a vehicle powertrain (3) are disclosed. The method comprises a step of estimating (S110) a torque consumed by a power take-off (PTO), connected to the vehicle powertrain, based on a parameter determined by a sensor (16a, 16b, 16c, 16d) arranged in the vehicle powertrain; and a step of controlling (S120) the torque provided by the power unit (2) during a gearshift taking into account the estimated torque consumed by the power take-off (PTO). The disclosure further relates to a computer program and a computer-readable medium, as well as a vehicle powertrain and a vehicle.

Description

METHOD AND ARRANGEMENT FOR CONTROLLING A VEHICLE POWERTRAIN WITH A POWER TAKE-OFF DURING GEARSHIFT TECHNICAL FIELD The present disclosure relates in general to a method for controlling a vehicle powertrain, and acontrol device configured to control a vehicle powertrain. Moreover, the present disclosure relates ingeneral to a computer program and a computer-readable medium. The present disclosure further relates in general to a vehicle powertrain as well as a vehicle.

BACKGROUND Vehicle powertrains usually comprises a power unit connected to the drive wheels via various shaftsand one or more gearboxes to transform the output torque of the power unit to a greater torque onthe drive wheels. Any change in said torque or power unit rotational speed, for example during gearshifting, may induce oscillations in the powertrain. These oscillations may cause discomfort for thedriver. lt is previously known to reduce these oscillations for example by limiting the rate of change for the power unit torque or actively controlling the power unit. ln addition to propelling the vehicle, a vehicle powertrain may also be used to drive one or moreauxiliary devices, such as power take-offs. Examples of power take-offs include pumps, cranes,mixers, compressors or the like. For the purpose of driving a power take-off, the vehicle powertrainmay comprise one or more devices configured to enable connection of a power take-off to thevehicle powertrain and transmit energy to the power take-off. A device configured to enableconnection of a power take-off may be connected to the gearbox, for example to a lay shaft of thegearbox. Thereby, the lay shaft may drive the power take-off by virtue of rotational energy from thelay shaft being transmitted to the power take-off. A device configured to enable connection of apower take-off may also be connected to for example a main shaft of the gearbox via a cogwheelarrangement. A power take-off may alternatively be connected to the vehicle powertrain outside thegearbox. For example, a device configured to enable connection of a power take-off may be arranged on a shaft of the power unit, or be connected to the flywheel.

When a power take-off is connected to and driven by the vehicle powertrain, it results in a load onthe vehicle powertrain that may affect the operation of the vehicle powertrain for the purpose of propelling the vehicle. This may in particular present problems during gear shifting when the power unit torque and/or rotational speed should be changed. The vehicle manufacturer is often not awareof which power take-offs a customer or user of the vehicle intends to connect to the vehiclepowertrain, and in particular not when such power take-offs , if connected, may consume energyfrom the vehicle powertrain. Therefore, the control of the vehicle powertrain is in general notadapted to a power take-off load since this load is not known. Furthermore, the actual torque in thepowertrain is in general not measured in situ. lnstead, the control of the powertrain is dependent ontorque estimated by a controller configured therefore. Although the control can be somewhatadapted by tuning for safety, such as adapting the torque ramp, this may lead to a sacrifice in performance and comfort in the operation of the vehicle. lt is previously known to determine the load applied by the power take-off by means of differenttorque sensors arranged on the connected power take-off. Such sensors are thus provided by themanufacturer of the power take-off, and not by the vehicle manufacturer. lnterfaces between thesensors and the vehicle control systems are therefore required in order to be able to take intoaccount the load of the power take-off when controlling the powertrain for the purpose ofpropulsion of the vehicle. Such interfaces may be complicated and introduce risks for errors in thecontrol of the vehicle powertrain. Furthermore, such a torque sensor is in general a fairly large component, and may add unnecessary weight.

For example, US 2006/0116238 A1 discloses a method and arrangement for providing an automaticgear-shift procedure for a vehicle with engaged clutch-dependent power take-off when the vehicle isin motion. The power take-off is driven by an engine via an automated disk clutch and an automaticstage-geared gearbox in which an intermediate shaft for driving the power take-off is arranged. Acontrol unit controls the gearbox, the disk clutch and the engine so that shifting when the vehicle ismotion can take place even with an engaged clutch-dependent power take-off. The torque at the power take-off is sensed by a torque transmitter arranged on the input shaft of the power take-off.

Another example is given in US 2010/0022348 A1, which discloses a method for adapting a drivetrain based upon a power take-off load. The method comprises determining a torque magnitudeindicative of the power take-off's torque consumption by sensing a fluid pressure produced by apower take-off fluid pump. The sensed power take-off unit torque consumption is compared with anoutput torque produced by the prime mover of the drive train. The operation of the drive train isadjusted in consideration of a by the power take-off unit reduced torque available for application to an output shaft of the transmission under driving conditions.

SUMMARY The object of the present invention is to improve the control of the vehicle powertrain during agearshift when an unknown power consumer, in the form of a power take-off, is connected to the vehicle powertrain.

The object is achieved by means of the subject-matter of the appended independent claims. ln accordance with the present disclosure, a method for controlling a vehicle powertrain is provided.The method is performed by a control device. The vehicle powertrain comprises a power unit and agearbox. The method comprises the steps of: - estimating a torque consumed by a power take-off, connected to the vehicle powertrain, based on a parameter determined by a sensor arranged in the vehicle powertrain, and- controlling the torque provided by the power unit during a gearshift taking into account the estimated torque consumed by the power take-off.

By means of the present method, reliable information of the torque consumed by a power take-offduring operation of the vehicle powertrain may be obtained. Thereby, it is possible to actively controlthe vehicle powertrain during a gearshift with any type of load caused by a possibly connected powertake-off without sacrificing performance or comfort when a vehicle comprising the vehiclepowertrain is in motion. More specifically, by controlling the torque provided by the power unitduring a gearshift taking into account the estimated torque consumed by the power take-off, thepower take-off load on the vehicle powertrain may be compensated for by adjustment of the torquedemanded from the power unit during gear shifting. Furthermore, by means of the present method,there is no need for an interface between the control device of the vehicle powertrain and forexample a controller of the power take-off, and therefore improves the reliability of the control of the vehicle powertrain.

The parameter determined by the sensor arranged in the vehicle powertrain may constitute aparameter resulting from a reaction force in a shaft of the gearbox. For example, the parameter maybe a pressure force resulting from the reaction force in a shaft of the gearbox. This has the advantageof ena bling an easy, but yet reliable, way of estimating the torque consumed by a power take-off that may be unknown to the vehicle manufacturer. This in turn increases the reliability in the control of the vehicle powertrain, which in turn reduces the risk for reduced performance and/or comfort during gear shifting.

The sensor may be configured to determine a parameter of a shaft of the vehicle powertrain onwhich a device configured to enable connection of a power take-off is arranged. Thereby, the reliability in the estimated torque consumed by the power take-off may be improved.

The step of controlling the torque provided by the power unit during a gearshift taking into accountthe estimated torque consumed by the power take-off may comprise controlling the torque providedby the power unit so as to achieve a target torque over a clutch of the vehicle powertrain which iszero. Alternatively, this step may comprise controlling the torque provided by the power unit so as toachieve a target torque over a gear to be disconnected which is zero. Thereby, a smooth gear shiftcan be achieved. At the same time, it is enabled that a power take-off can be operated as desired by a vehicle user during the gear shift.

The present disclosure further relates to a computer program comprising instructions, which whenexecuted by a control device, cause the control device to perform the method for controlling a vehicle powertrain as described above.

The present disclosure further relates to a computer-readable medium comprising instructions,which when executed by a control device, cause the control device to perform the method for controlling a vehicle powertrain as described above. ln accordance with the present disclosure, a control device configured to control a vehiclepowertrain is provided. The vehicle powertrain comprises a power unit and a gearbox. The controldevice is configured to estimate a torque consumed by a power take-off, connected to the vehiclepowertrain, based on a parameter determined by a sensor arranged in the vehicle powertrain. Thecontrol device is further configured to control the torque provided by the power unit during a gearshift taking into account the estimated torque consumed by the power take-off.

The control device has the same advantages as described above with regard to the corresponding method for controlling a vehicle powertrain.

As disclosed above, the control device is configured to estimate the torque consumed by a power take-off connected to the vehicle powertrain based on a parameter determined by a sensor arranged in the vehicle powertrain. Said parameter may constitute a parameter resulting from a reaction forcein a shaft of the gearbox. The parameter may be a pressure force resulting from the reaction force in a shaft of the gearbox.

The sensor may be configured to determine a parameter of a shaft of the vehicle powertrain on which a device configured to enable connection of a power take-off is arranged.

Moreover, the control device may be configured to control the torque provided by the power unitduring a gearshift taking into account the estimated torque by the power take off so as to achieve atarget torque over a clutch of the vehicle powertrain, or a gear to be disconnected during the gearshift, which is zero.

The control device may further be configured to control the rate of change of the power unit torque during a gearshift taking into account the stiffness of the vehicle powertrain.

The present disclosure further relates to a vehicle powertrain comprising the control device as described above.

The present disclosure also relates to a vehicle comprising the control device as described above.

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 schematically illustrates a side view of a vehicle; Fig. 2 schematically illustrates one exemplifying embodiment of a vehicle powertrain; Fig. 3 schematically illustrates another exemplifying embodiment of a vehicle powertrain; Fig. 4 represents a flowchart schematically illustrating a method of controlling a vehicle powertrain according to one exemplifying em bodiment;Fig. 5 schematically illustrates a device that may constitute, comprise or be a part of a control device configured to control a vehicle powertrain.

DETAILED DESCRIPTION The invention will be described in more detail below with reference to exemplifying embodimentsand the accompanying drawings. The invention is however not limited to the exemplifyingembodiments discussed and/or shown in the drawings, but may be varied within the scope of theappended claims. Furthermore, the drawings shall not be considered drawn to scale as some features may be exaggerated in order to more clearly illustrate the invention or features thereof. ln the present disclosure, a ”power take-off" is considered to mean an auxiliary device, which may beconnected to the vehicle powertrain but is not a part of the vehicle powertrain as such. Examples ofsuch ”power take-offs" include, but are not limited to various pumps, cranes, mixers (such as a concrete mixer), and compressors. ln contrast, a device configured to enable connection of a power take-off is in the present disclosureconsidered to a constituent component of the vehicle powertrain, or a component permanently connected to the vehicle powertrain and provided by the vehicle manufacturer.

A vehicle powertrain usually comprises at least one power unit and a driveline. The driveline may forexample comprise one or more gearboxes and various shafts. The one or more gearboxes areconfigured to selectively transfer torque between the power unit and the driving wheels. ln otherwords, the output torque of the power unit is transformed via the driveline to a greater torque onthe driving wheels. Any change in the output torque or rotational speed of the power unit mayinduce unwanted oscillations in the powertrain. This may in particular occur during gear shiftingwhen there in general is a need for a fast change in the output torque or rotational speed. However,the unwanted oscillations may be minimised by limiting the rate of change for power unit torque or actively controlling the power unit.

To actively control the power unit, it is important to consider some key properties of the driveline,such as driveline stiffness, driveline damping, driveline inertia or driveline backlash. These keyproperties of the driveline can be estimated using material properties and drawings of thecomponents, or measured in a rig. The powertrain stiffness may however be the property of greatestsignificance as it holds the key to knowing how the driveline will react to changes in power unit torque.

Dynamic flywheel torque, the torque applied to the flywheel by the power unit can be described asthe torque felt in the driveline. lf the dynamic torque is smooth, there are no driveline oscillations.The dynamic torque Tflywhee, at the flywheel can be described in accordance with Equation 1, whereTe is the torque produced by the power unit,] is the moment of inertia of the power unit, and (be isthe angular acceleration of the power unit.Eq- 1 Tflywheel = Te _]¿beRewritten, considering the driveline as a weak torsional spring, the dynamic torque Tflywhee, at theflywheel can be expressed in accordance with Equation 2.Eq- 2 Tflywheel = k(6e _ Qwheel) + CÛÜe _ wwheel) ln Equation 2, k is the torsional stiffness coefficient (i.e. the spring constant) of the driveline, cis thecorresponding damping coefficient of the driveline, Ge is the angle of the power unit, Qwhee, is the angle of the driving wheels, we is the angular velocity (i.e. rotational speed) of the power unit, and wwhee, is the angular velocity (i.e. rotational speed) of the driving wheels.

The damping effects in the powertrain are generally small and can therefore often be neglected. lnother words, c can be assumed to be zero. This leads to a simplified version of Equation 2 as given inEquation 3.

Eq- 3 Tflywheel = k(6e _ ewheel)The derivative of Equation 3 is given by Equation 4, wherein we is the rotational speed of the powerunit and wwhee, is the rotational speed of the driving wheels.

Eq- 4 Tflywheel = k(we _ wwheel)lt is hereby understood that by controlling the torque derivative, one controls the changes in flywheel torque. To do this, the stiffness coefficient k is key to how big the oscillations will be for a given torque derivative.

The actual torque is not measured in the powertrain, but estimated by the power unit managementsystem and/or another controller. Therefore, although the above described control of the vehiclepowertrain works very well in most instances, the equations are not valid in case there is anunknown power consumer, such as a power take-off. More specifically, the considerations above donot take into account any torque consumed by a power take-off possibly connected to the vehiclepowertrain. This may lead to disturbances and reduced comfort. ln particular, the performance andcomfort is limited with high load power take-offs and the maximum torque that can be used during agearshift is very limited. The method and control device according to the present disclosure address these issues.

The present disclosure provides a method for controlling a vehicle powertrain, the vehiclepowertrain comprising at least a power unit and a gearbox. The method is typically performed whena vehicle, comprising the vehicle powertrain, is in motion. The method is performed by a controldevice configured therefore. The method may optionally be activated based on a detection that apower take-off has been connected to the vehicle powertrain, although the present disclosure is notlimited thereto. For example, the method may be performed continuously during operation of thevehicle powertrain. Thereby, it is not necessary to know whether or not a power take-off is currently connected, or if the power take-off is currently driven by the vehicle powertrain.

The method according to the present disclosure comprises a step of estimating a torque consumedby a power take-off connected to the vehicle powertrain. A torque is consumed by a power take-offif the power take-off is driven by the vehicle powertrain. The estimation of the torque consumed bythe power take-off is performed based on a parameter determined by a sensor arranged in thevehicle powertrain. Thereby, it is not necessary to rely for example on torque transmitters or the likearranged at the power take-off and an interface between the control device and such a torquetransmitter. The method further comprises a step of controlling the torque provided by the powerunit during a gearshift taking into account the estimated torque consumed by the power take-off. ln |H other words, the method comprises adapting the "norma control of torque provided by the powerunit during the gearshift to the estimated torque consumed by the power ta ke-off from the vehicle powertrain so as to compensate for the power take-off load.

By means of the present method, the active control of the power unit during a gearshift is adapted tothe potential presence of an unknown consumer of torque. Thereby, it is ensured that the gearshifting process is not disturbed by a potential active power take-off driven by the vehicle powertrain. Furthermore, the risk for unwanted oscillations in the vehicle powertrain during gear shifting is significantly reduced. The control of the torque provided by the power unit during agearshift may be performed by any previously known measures therefore as long as it performedtaking into account the estimated torque consumed by the power take-off. For example, the controlof the torque provided by the power unit may comprise controlling the rotational speed of the powerunit. The control of the torque provided by the power unit may also for example comprise controlling the fuel injection in case the power unit is a combustion engine.

The parameter determined by the sensor arranged in the vehicle powertrain may constitute aparameter resulting from a reaction force in a shaft of the vehicle powertrain. When the power take-off is a power take-off connected to the gearbox, such a shaft may for example be a shaft of thegearbox. The parameter may for example be a pressure force resulting from a reaction force in a shaft of the vehicle powertrain.

The sensor used for determining a parameter from which the consumed torque can be estimatedmay for example comprise a strain gauge bridge (such as a Wheatstone bridge), and can thus bemade very small and easily fit into the vehicle powertrain. The sensor may be attached directly to ashaft of the vehicle powertrain, for example a shaft of the gearbox. Alternatively, the sensor may beincorporated into a separate, or already existing, bearing or the like of the vehicle powertrain as desired.

The sensor is configured to determine the parameter that may be used to estimate a torque. Forexample, the sensor may be configured to determine a parameter resulting from a reaction force in ashaft of the vehicle powertrain, such as a reaction force in a shaft of the gearbox. The parametercould for example be a pressure force in a constituent component resulting from such a reaction force in a shaft of the gearbox.

By way of example, a reaction force in a shaft of the gearbox (during operation of the vehicle) maytransmit a pressure force on a bearing arranged on such a shaft and a sensor arranged in said bearingmay detect the resulting pressure force in the bearing. The detected pressure force may then beconverted to a corresponding torque. The determined corresponding torque may then be used toestimate the torque consumed by a possible power take-off consumer by means of comparison with an expected torque of the shaft.

The sensor may be configured to determine a parameter of a shaft on which the device configured to enable a connection of a power take-off is arranged. ln other words, the sensor may be configured to determine the parameter on the shaft that is directly subjected to the load from the power take-off.This could for example be achieved by arranging the sensor at the shaft to which the deviceconfigured to enable connection of a power take-off is arranged. lt is however also possible that thesensor is configured to determine a parameter of a shaft of the vehicle powertrain other than theshaft on which the device configured to enable a connection of a power take-off is arranged. ln sucha case, the determined parameter may be converted into a corresponding parameter of the shaft onwhich the device configured to enable connection of a power take-off is arranged. According to yetan alternative, it may not be necessary to estimate the torque on the shaft on which the deviceconfigure to enable connection of a power take-off is arranged. lnstead, it may for example besufficient for the sensor to determine a parameter of for example an input shaft of the gearbox andbased on an expected torque on the input shaft determining the estimated torque consumed by thepower take-off on said input shaft of the gearbox. This may for example be sufficient in case where aclutch connecting the power unit to the input shaft of the gearbox is to be opened or closed duringgear shifting, i.e. when there is a desire to obtain a zero clutch torque. This may also be sufficient in case where a gear is to be connected or disconnected in the gearbox during gear shifting.

The above described method may further comprise a step of controlling the rate of change of torqueprovided by the power unit during a gearshift. ln other words, the method may further comprise astep of actively controlling the rate of change of torque provided by the power unit during the torqueramps during gear shifting. This step may suitably be performed taking into account the stiffness of the vehicle powertrain.

The present disclosure further relates to a control device configured to control a vehicle powertrain,the vehicle powertrain comprising a power unit and a gearbox. The control device is configured toestimate a torque consumed by a power take-off, connected to the vehicle powertrain, based on aparameter determined by a sensor arranged in the vehicle powertrain. The control device is furtherconfigured to control the torque provided by the power unit during a gearshift taking into accountthe estimated torque consumed by the power take-off. The control device may further be configuredto perform any one of the steps described above with regard to the corresponding method forcontrolling a vehicle powertrain. The control device may further be configured to control the rate ofchange if the power unit torque during a gearshift taking into account the stiffness of the vehicle powertrain.

Figure 1 schematically illustrates a side view of an example of a vehicle 1. The vehicle 1 comprises a powertrain 3 comprising a power unit 2 and a gearbox 4. The power unit 2 may for example constitute a combustion engine, but is not limited thereto. A clutch (not shown) may be arranged between the power unit 2 and the gearbox 4. The gearbox 4 is connected to the driving wheels 5 ofthe vehicle 1 via an output shaft 6 of the gearbox 4. The gearbox 4 is adapted to provide a pluralityof gear ratios. The gearbox 4 may for example be an automated manual gearbox (AMT) as known in the art, but is not limited thereto.

The vehicle 1 may be a heavy vehicle, e.g. a truck. Furthermore, the vehicle may be a hybrid vehiclecomprising a first power unit in the form of a combustion engine and a second power unit in theform of an electric machine. Alternatively, the vehicle may be an electrical vehicle in which case the power unit is an electrical machine and no combustion engine is present.

Figure 2 schematically illustrates an exemplifying embodiment of a vehicle powertrain 3, such as apowertrain of the vehicle 1 shown in Figure 1. The powertrain 3 comprises a power unit 2 in the formof a combustion engine. The powertrain further comprises a gearbox 4 having an output shaft 6 thatis connected to the driving wheels 5 via a differential 11. The vehicle powertrain 3 further comprisesa clutch 9 arranged between the output shaft 7 of the power unit 2 and the input shaft 10 of thegearbox 4. The gearbox 4 may for example be an automated manual gearbox (AMT) as known in theart, but is not limited thereto. The gearbox 4 may alternatively comprise a first and second planetary gear, each with a respective electrical machine.

The vehicle powertrain 3 furthermore comprises a control device 100, as will be described in moredetail below. The control device 100 is configured to control at least parts of the vehicle powertrain3. More specifically, the control device 100 is configured to control at least the power unit 2 and the gearbox 4.

The vehicle powertrain 3 may further comprise at least one device configured to enable connectionof a power take-off, PTO, such that the PTO may be driven by the powertrain. ln view of such apower take-off not being a part of the vehicle powertrain 3, the PTOs are illustrated in Figure 2 in theform of a dashed boxes. For example, the vehicle powertrain 3 may comprise a first device 15aconfigured to enable connection of a power take-off. The device 15a is arranged at the gearbox.Alternatively, or additionally, the vehicle powertrain may comprise a second device 15b configuredto enable connection of a power take-off. The second device 15b may for example be connected tothe output shaft 7 of the power unit via a gear wheel arrangement 14 configured therefore. A powertake-off connected to the vehicle powertrain 3 via the second device 15b may thus be driven by the rotation of the output shaft of the power unit 2. Alternatively, the vehicle powertrain 3 may comprise a third device 15c configured to enable connection of a power take-off. The third device15c is arranged at the power unit, but is connected to another shaft of the power unit 2 than theoutput shaft 7 of the power unit 2. Any one of the above described devices configured to enableconnection of a power take-off may have any configuration as previously known in the art. For example, it may be a splined shaft, a yoke or the like.

The vehicle powertrain 3 may further comprise one or more sensors configured to determine aparameter from which the torque consumed by a possibly connected power take-off can beestimated. The parameter may for example be a parameter resulting from a reaction force in a shaftof the gearbox, a shaft of the power unit, or a shaft directly connected to the above described deviceconfigured to enable connection of a power take-off to the vehicle powertrain. For example, a firstsensor 16a may be arranged in the gearbox. Alternatively, or additionally, a second sensor 16b maybe arranged at a gear wheel arrangement 14 connecting the output shaft 7 of the power unit to thesecond device 15b configured to enable connection of a power take-off. Alternatively, oradditionally, a third sensor 16c may be arranged in the power unit such that it can determine aparameter of a shaft directly connected to the third device 15c configured to enable connection of apower take-off. lt is also possible to incorporate a fourth sensor 16d configured to determine aparameter from which the torque consumed by a possibly connected power take-off. Such a fourthsensor 16d may be arranged at the input shaft 10 of the gearbox 4. The fourth sensor 16d may forexample be used instead of the first sensor 16a to estimate the torque consumed by a power take-off connected to the gearbox via the first device 15a configured to enable connection of a powertake-off. Alternatively, the fourth sensor 16d may be used together with the first sensor 16a for thepurpose of increasing the reliability by having more than one parameter for estimating the torque consumed by a possibly connected power take-off.

Figure 3 schematically illustrates another exemplifying embodiment of a vehicle powertrain 3, suchas a powertrain of the vehicle 1 shown in Figure 1. The powertrain 3 comprises a power unit 2, suchas a combustion engine. The powertrain further comprises a gearbox 4 having an output shaft 6which is connected to the driving wheels 5. A clutch 9 may be arranged between the power unit 2 and the gearbox 4.

The gearbox 4 comprises a lay shaft 20. A plurality of gear wheels 22B, 23B, 24B are rotata bly fixed tothe lay shaft 20. The gearbox 4 also comprises a main shaft 30 with corresponding gear wheels 22A,23A, 24A that rotate freely in relation to the main shaft 30, but which can be selectively locked for rotation with the main shaft 30 in order to engage a gear. When each of the gear wheels 22A, 23A, 24A rotate freely in relation to the main shaft 30, the gearbox 4 is in neutral. Thereby, no torque istransmitted from the power unit 2 to the driving wheels 5. The gear wheels 22A, 23A, 24A of themain shaft 30 may be locked by means of corresponding coupling sleeves 26, 27, 28. Each pair of gear wheels on the lay shaft 20 and main shaft 30 represents a gear ratio.

The lay shaft 20 further comprises an additional gear wheel 25B that, similar to the above, is rotata bly fixed to the lay shaft 20. The gearbox 2 also comprises a corresponding gear wheel 25Arotating freely in relation to the input shaft 10, but which may be selectively locked for rotation withthe input shaft 10 through a split sleeve 28. When the split sleeve 28 locks the gear wheel 25A withthe input shaft 10, torque can be transferred to the lay shaft 20 via the corresponding gear wheel 25B on the lay shaft 20.

The vehicle powertrain 3 may comprise a first device 15a configured to enable connection of a powertake-off, the device 15a being connected to the lay shaft 20 of the gearbox 4. Alternatively, oradditionally, the vehicle powertrain may comprise a fourth device 15d configured to enableconnection of a power take-off. Said fourth device 15d is arranged on a shaft 29b comprising a gearwhen 29b. The gear wheel 29b may be connected to the gear wheel 22A of the main shaft 30.

Thereby, when gear wheel 22A is rotating, gear wheel 29b and the shaft 29a will rotate.

The vehicle powertrain 3 further comprises at least one sensor configured to determine a parameter,based on which a torque consumed by a power take-off connected to the vehicle powertrain may beestimated. ln Figure 3, this is illustrated by a sensor 16d arranged at the input shaft of the gearbox 4.lt should however be noted that such a sensor may be arranged at any one of the input shaft 10, the lay shaft 20, the main shaft, and/or, if present, the shaft 29a.

The control of the vehicle powertrain 3 as shown in any one of Figures 2 and 3, including the controlof the individual constituent components of such a vehicle powertrain, may be governed byprogrammed instructions. These programmed instructions typically take the forms of a computerprogram which, when executed in a computer or control unit, causes the computer or control unit toeffect desired forms of control action, for example the steps of the method disclosed herein. Such a computer or control unit may be or constitute a part of the control device 100.

Figure 4 represents a flowchart schematically illustrating a method of controlling a vehiclepowertrain according to an exemplifying em bodiment of the present disclosure. The vehicle powertrain comprises a power unit and a gearbox. The method comprises a step, S110, of estimating a torque consumed by a power take-off based on a parameter determined by a sensor arranged inthe vehicle powertrain. The step S110 may be performed only when it has been determined that apower take-off is connected to the vehicle powertrain. Alternatively, it may be performedcontinuously, in which case the power consumed by a power take-off is estimated to be zero in casethere would be no power take-off connected to the vehicle powertrain or a connected power take-off is inactive and thereby does no consume torque from the vehicle powertrain. The method furthercomprises a step, S120, of controlling the torque provided by the power unit during a gearshift takinginto account the estimated torque consumed by the power ta ke-off. Step S120 may comprisecontrolling the torque provided by the power unit so as to achieve a target torque over a clutch ofthe vehicle powertrain, or a gear (of the gearbox) to be disconnected. The target torque over said clutch or over said gear to be disconnected may be zero.

Figure 5 schematically illustrates an exemplifying embodiment of a device 500. The control device100 described above may for example comprise the device 500, consist of the device 500, or be comprised in the device 500.

The device 500, shown in the figure, comprises a non-volatile memory 520, a data processing unit510 and a read/write memory 550. The non-volatile memory 520 has a first memory element 530 inwhich a computer program, e.g. an operating system, is stored for controlling the function of thedevice 500. The device 500 further comprises a bus controller, a serial communication port, I/Omeans, an A/D converter, a time and date input and transfer unit, an event counter and aninterruption controller (not depicted). The non-volatile memory 520 has also a second memory element 540.

There is provided a computer program P that comprises instructions for controlling a vehiclepowertrain, wherein the vehicle powertrain comprises a power unit and a gearbox. The computerprogram may comprise instructions for estimating a torque consu med by a power take-off connectedto the vehicle powertrain based on a parameter determined by a sensor arranged in the vehiclepowertrain. The computer program may further comprise instructions for controlling the torqueprovided by the power unit during a gearshift taking into account the estimated torque consumed by the power ta ke-off.

The program P may be stored in an executable form or in a compressed form in a memory 560 and/or in a read/write memory 550.

The data processing unit 510 may perform one or more functions, i.e. the data processing unit 510may effect a certain part of the program P stored in the memory 560 or a certain part of the program P stored in the read/write memory 550.

The data processing device 510 can communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is intended for communication with the data processing unit 510 via a data bus512. The separate memory 560 is intended to communicate with the data processing unit 510 via adata bus 511. The read/write memory 550 is adapted to communicate with the data processing unit510 via a data bus 514. The communication between the constituent components may beimplemented by a communication link. A communication link may be a physical connection, such asan optoelectronic communication line, or a non-physical connection, such as a wireless connection, e.g. a radio link or microwave link.

When data are received on the data port 599, they may be stored temporarily in the second memoryelement 540. When input data received have been temporarily stored, the data processing unit 510 is prepared to effect code execution as described above.

Parts of the methods herein described may be effected by the device 500 by means of the dataprocessing unit 510 which runs the computer program stored in the memory 560 or the read/writememory 550. When the device 500 runs the computer program, methods herein described are executed.

Claims

1. A method for controlling a vehicle powertrain (3), the method performed by a control device (100), the vehicle powertrain (3) comprising: a power unit (2), and a gearbox (4),the method being characterised by comprising steps of: estimating (S110) a torque consumed by a power take-off (PTO), connectedto the vehicle powertrain, based on a parameter determined by a sensor (16a, 16b,16c, 16d) arranged in the vehicle powertrain, and controlling (S120) the torque provided by the power unit (2) during agearshift taking into account the estimated torque consumed by the power take-off (PTO).

2.The method according to claim 1, wherein the parameter determined by the sensor arrangedin the vehicle powertrain constitutes a parameter resulting from a reaction force in a shaft (10, 20, 30, 29a) of the gearbox (4).

3.The method according to claim 2, wherein the parameter is a pressure force resulting from the reaction force in a shaft (10, 20, 30, 29a) of the gearbox (4).

4.The method according to any one of the preceding claims, wherein the sensor is configuredto determine a parameter of a shaft of the vehicle powertrain on which a device (15a, 15b, 15c, 15d) configured to enable connection of a power take-off is arranged.

5.The method according to any one of the preceding claims, wherein controlling the torqueprovided by the power unit (2) during a gearshift taking into account the estimated torqueconsumed by the power take-off comprises controlling the torque provided by the powerunit (2) so as to achieve a target torque over a clutch (9) of the vehicle powertrain, or a gear to be disconnected, which is zero.

6.A computer program comprising program code for causing a control device to perform the method according to any one of the preceding claims.

7.A computer-readable medium comprising instructions, which when executed by a controldevice, cause the control device to perform the method according to any one of claims 1 to

8.A control device (100) configured to control a vehicle powertrain (3),the vehicle powertrain (3) comprising:a power unit (2), anda gearbox (4),wherein the control device (100) is configured to estimate a torque consumed by apower take-off (PTO), connected to the vehicle powertrain (3), based on a parameterdetermined by a sensor (16a, 16b, 16c, 16d) arranged in the vehicle powertrain,the control device (100) further configured to control the torque provided by thepower unit (2) during a gearshift taking into account the estimated torque consumed by the power ta ke-off (PTO).

9.The control device (100) according to claim 8, wherein the parameter determined by asensor arranged in the vehicle powertrain (3) constitutes a parameter resulting from a reaction force in a shaft (10, 20, 30, 29a) of the gearbox (4).

10.The control device (100) according to claim 9, wherein the parameter is a pressure force resulting from the reaction force in a shaft (10, 20, 30, 29a) of the gearbox (4).

11.The control device (100) according to any one of claims 8 to 10, wherein the sensor (16a,16b, 16c, 16d) is configured to determine a parameter of a shaft of the vehicle powertrain onwhich a device (15a, 15b, 15c, 15d) configured to enable connection of a power take-off is arranged.

12.The control device (100) according to any one of claims 8 to 11, wherein the control device isconfigured to control the torque provided by the power unit (2) during a gearshift taking intoaccount the estimated torque by the power take off (PTO) so as to achieve a target torque over a clutch (9) of the vehicle powertrain, or a gear to be disconnected during the gearshift, which is zero.

13. The control device (100) according to any one of claims 8 to 12, wherein the control device isfurther configured to control the rate of change of the power unit (2) torque during a gearshift taking into account the stiffness of the vehicle powertrain (3).

14. A vehicle powertrain (3) comprising a control device (100) according to any one of claims 8 to

15. A vehicle (1) comprising a control device (100) according to any one of claims 8 to 13.