DE102019109314A1 - Method for controlling a travel drive of a mobile work machine - Google Patents

Abstract

A method for controlling a travel drive provided in a mobile work machine is proposed, which comprises a drive motor, in particular an internal combustion engine, as well as a transmission, which is designed to output a drive torque output by the drive motor in a continuously variably modified manner. The method includes detecting at least one current state outside the travel drive that does not correspond to an immediate power demand, making a prediction about a future power demand taking into account the detected current state, and, in particular, adjusting the propulsion depending on the prediction the drive motor, the gearbox and possibly an additional motor are adjusted.

Description

The present invention relates to a method for controlling a drive provided in a mobile work machine, comprising a drive motor, in particular an internal combustion engine, and a transmission, which is adapted to output a outputted from the drive motor drive torque continuously variable modified. For example, the transmission may be configured to continuously variably translate the drive torque output by the drive motor and / or to sum with a drive torque output by an auxiliary motor, in particular an electric motor, the additional motor and / or the summation being infinitely variable. In these various ways, the traction drive for outputting a drive torque which is infinitely variable within certain limits can be actuated, which no longer depends directly and exclusively on the drive motor, but is modified by a further drive torque due to the transmission ratio and / or summation.

If the transmission has a continuously variable transmission, this transmission may be, for example, a power-split transmission comprising a first power branch and a second power branch, wherein the first power branch has a fixed ratio or is switchable between a plurality of fixed ratios and wherein second power branch has an adjustable variator over which the translation of the second power branch is continuously variable. In this case, the transmission between different driving ranges is switchable, in each of which by adjusting the variator, the total ratio of the transmission is infinitely variable within a transmission range associated with the respective driving range.

The stepless modification of the drive torque allows a particularly flexible adaptability of the travel drive to the respective operating situation of the mobile work machine. In a power-split transmission, for example, rotational speeds and torques within a respective driving range in which at least part of the power is transmitted via the variable second power branch can be transmitted with continuously variable transmission. If a plurality of such driving ranges overlap one another or at least adjoin one another, the ratio can also be steplessly adjustable over a plurality of driving ranges. However, not only driving ranges can be provided in which the power is partly transmitted by the first and partly by the second power branch, but also driving ranges in which power is transmitted only by the first power branch or only by the second power branch. By adjusting the respective distribution to the power branches and the respective gear ratio in the two power branches, the travel drive, in particular with regard to the highest possible efficiency, can be operated adapted to different operating situations. Similarly, in a traction drive with an additional motor, for example, in a diesel-electric drive train, by adjusting the additional motor or the summation of the drive torque of both engines modified the total output drive torque and the traction drive characterized, in particular with regard to the highest possible efficiency, to different operating situations be operated appropriately.

An optimized tuning, i. a coordinated adjustment of the drive motor and the transmission and optionally the additional motor. This ensures, for example, that a respective driving speed can be achieved due to the stepless adjustability at different rotational speeds of the drive motor, from which then the most favorable in terms of the desired optimization speed can be selected. Typically, the aim is the lowest possible engine speed.

If the traction drive comprises a power-split transmission, the first power branch may in particular be a power branch with purely mechanical power transmission. The second power branch can in particular be designed to transmit drive torque hydrostatically, wherein the variator is then preferably formed by a, in particular adjustable, hydraulic motor and a, in particular adjustable, hydraulic pump. In principle, however, the second power branch can also be designed for a different type of power transmission and have, for example, a mechanical, a hydrodynamic or an electrical variator. The power components respectively transmitted by the first and second power branches are preferably combined at a summation element of the transmission and ultimately output. Alternatively or additionally, it is also possible to provide a branching element, at which the power is distributed to the two power branches. The summing element or the branching element may be, for example, a planetary gear.

The first power branch can be switched between different fixed translations. In this case, the first power branch can also have a reversing stage, by which a drive direction reversal, preferably with at least substantially the same amount of translation, can be achieved. In addition, a possibility can be provided by means of a clutch, for example, to completely interrupt the first power branch. In particular, can be switched by switching between the various translations and / or by the interruption or closing of the first power branch between the different driving ranges in which the overall ratio of the transmission is then continuously variable via the variator.

For efficient use of the traction drive, it is important to select and set the most suitable driving range for the current operating situation. This can basically be done manually. For example, operating elements can be provided on the mobile work machine via which the driver or another user of the work machine can manually specify a respective power requirement, in particular a respective torque request. Such an operating element can be, for example, an accelerator pedal, by which a rotational speed of the drive motor of the traction drive can be changed, wherein this change can then also be taken into account for the control of the transmission. Alternatively or additionally, other manually operated controls can be provided by the gear directly adjusted, in particular between different translations or driving ranges, can be, for example, a shift lever or switch button or the like. Furthermore, it can be provided that a driver or user of the mobile work machine can manually select via operating means between different, in particular different dynamic, operating modes of the travel drive.

When manually specifying respective modes of operation or direct drive power requirements, there is the problem that the mobile work machine may be operated improperly or at least not ideally in terms of efficiency or otherwise. For this reason or to increase the comfort, it may be useful if at least certain settings of the drive are automated. For example, speeds can be monitored in the transmission and depending on switching operations between different driving ranges are triggered. It is not excluded by the automatic operation that, if necessary, additional manual operations are taken into account. For example, the switching of the respectively suitable driving range can also be dependent, inter alia, on an immediate power requirement, for example on how strongly or quickly an accelerator pedal is stepped on.

Such automatic systems usually only take into account conditions within the drive motor and possibly the additional motor or the transmission itself, such as the rotational speeds of transmission elements or the power flow through the transmission, and / or immediate power requirements, by the drive motor and optionally the auxiliary motor or the transmission, in particular by a user, typically manually, a desired setting can be at least partially specified. In addition, such an automatic system can only react to a changed operating situation, which results in a changed power requirement, i. to bring about a suitable adaptation to the changed power requirement only when the operating situation has already changed. Until the adaptation is completed, the traction drive is therefore not optimally driven, which can lead to an overload of the transmission, the drive motor and / or other elements of the traction drive.

It is an object of the invention to provide an improved method for controlling a traction drive of the type mentioned, which also takes into account motor- and transmission-remote parameters and by a forward-looking and thus particularly efficient and the traction drive in sudden changes of the respective power requirement, in particular the respective torque request , gentle control of the traction drive can be achieved.

The object is achieved by a method having the features of claim 1, by a traction drive with the features of claim 21 and by a power-split transmission having the features of claim 22. Advantageous embodiments of the invention will become apparent from the present description, the dependent claims and the Figure.

According to the claim, the method comprises detecting at least one current state outside the travel drive that does not correspond to an immediate power requirement, making a prediction about a future power requirement taking into account the detected current state, and adjusting the travel drive depending on the prediction. In particular, the drive motor, the gearbox and possibly the auxiliary motor are adjusted. If the traction drive comprises a power-split transmission with variator, depending on the prediction, preferably the drive motor is adjusted, the transmission is switched and / or the variator is adjusted. Thus, depending on the prediction, an adaptation of the traction drive, which advantageously comprises a coordinated setting of the said elements of the traction drive, takes place. there It is not always necessary to adjust both the drive motor and, if necessary, the auxiliary motor and the gearbox. but each element is preferably only adjusted if a change of the respective element to adapt the operation to the respective prediction is required.

If the traction drive comprises a power-split transmission with a variator, in particular the drive motor is adjusted, the transmission is switched and / or the variator is adjusted, depending on the prediction. Preferably, both the transmission is switched as a function of the prediction and the variator is adjusted as a function of the prediction.

For the control of the traction drive so at least one state is considered instead of parameters of the drive motor or the transmission or in addition to such parameters, which is neither a state of the drive motor or the transmission itself or one of its parts, nor an immediate, for example by a user the mobile work machine by pressing an operating element provided for this purpose, corresponds to the power requirement. In this way, circumstances in the decision about an adjustment of the traction drive can be included for the control of the traction drive, which can not be derived from the state of the traction drive itself or parts thereof. In the case of the detected current state, it may be a state of the mobile work machine, in particular, but also information about an environment of the work machine can enter into the current state.

The adjustment of the traction drive is not or at least not exclusively in direct dependence on the detected current state. Rather, the detected current state is used to make a prediction about a future power request, in particular a future torque request. In other words, the detected current state serves as an essential indication of how the travel drive, in particular with regard to the transmission of power through the transmission, is to be operated next at least presumably. As a result, a forward-looking control of the traction drive is realized, which makes it possible to prepare the traction drive to an expected future power requirement in advance so that not only in the moment in which the requirement is concretely started, the traction drive to meet this requirement to control accordingly, but that the new power requirement is ideally already met at this moment.

The current state to be detected, from which the future power requirement is derived, is thereby to be distinguished from those states which correspond to an immediate power demand. For example, the position and the adjustment of an accelerator pedal, a shift lever or a switch button each correspond to an immediate power requirement. Preferably, in principle, the position and the adjustment of each manually operated control element, which serves to directly change or specify the drive motor, possibly the auxiliary motor or an operating mode of the transmission, an immediate power requirement and thus come as a basis for the prediction of a future power demand not considered. However, this does not preclude such conditions from being additionally taken into account for the prediction of the future performance requirement. However, since such states serve to specifically and directly predetermine a respective power demand on the transmission, in particular manually at a specific point in time, it is expedient for the control to respond directly to such power requirements and for the prediction of possible future power requirements to be based on other factors.

In particular, the prediction may be directed to a future performance request expected within a few minutes of the current time. This period may for example be at most five minutes, in particular at most two minutes, preferably at most one minute and / or at least ten seconds, in particular at least twenty seconds, preferably at least thirty seconds.

According to an advantageous embodiment, the transmission has a control device which is designed to adjust the travel drive in dependence on the prediction. In particular, it can thus be provided that the said method is carried out by the control device. In the control device then enters the information about the detected current state and is based on this information, the prediction of the future power requirement, according to which the control device then adjusts the traction drive, e.g. the drive motor adjusted, the transmission switched and / or adjusted, adjusted a variator of the transmission and / or optionally adjusted the auxiliary motor. Preferably, a common control device is provided for adjusting the various elements of the traction drive.

In this case, it is also advantageous if the control device receives the detected current state as at least one parameter, which of the Control device is provided via a CAN bus of the mobile machine. For example, the respective parameter, which represents the detected current state, for any other purpose of the mobile machine anyway collected and provided via the CAN bus. By virtue of the fact that the control device is advantageously connected to the CAN bus, the control device can simply read out the parameter in order to take it into account for the prediction of the future power requirement.

The current state to be taken into account for the prediction can be captured in various ways. Basically, the detection may also include that the current state is made up of different values, such as e.g. Measured values, only derived. Regardless of whether the current state is detected directly or derived, the current state can be detected according to an advantageous embodiment, in particular by means of at least one outside of the drive motor and the transmission, in particular outside the entire traction drive provided on the mobile machine sensor. The one or more measured values of one or more such sensors can then be received and evaluated in particular by the said control device. The sensors can be provided on the mobile work machine for other purposes, for example as part of an ABS system, anyway and detect conditions of the work machine. The sensors can also serve to detect conditions outside the mobile work machine, such as an outside temperature or a road surface. Other examples of sensors include acceleration and attitude sensors and position sensors, such as GPS sensors. However, not every parameter that is included in the current state taken into account for the prediction of future performance requirements must necessarily be detected by means of a sensor. For example, the time can also be included in the current state.

The mobile work machine may be, for example, an agricultural vehicle, in particular a tractor to which various implements and implements, such as a plow or a seeder, can be connected and operated. Other mobile work machines are e.g. Transport equipment, such as powered industrial trucks, especially wheel loaders or dump trucks, or mobile construction machinery. Furthermore, emergency vehicles, for example specially equipped fire brigade, rescue or accident assistance vehicles, e.g. Equipment motor vehicles, mobile machines.

According to a preferred embodiment, the detection of the current state comprises at least detecting a type, a position and / or an adjustment of a working device and / or an attachment of the mobile work machine. For the position of a working or attachment of the mobile machine and in particular the adjustment of the working or attachment in a special position can serve as an indication of an imminent change in the mode of operation of the mobile machine, with which a change in the power requirement is associated with the drive , Although the position of the working or attachment can be manually adjusted by means of a control element. However, such adjustment does not constitute an immediate power requirement on the traction drive, since the control element primarily serves to specify the position of the working or attachment to be taken, but this has no direct effect on the performance to be provided by the traction drive. Only by the fact that the position or the adjustment of the work or attachment as an indication of a power requirement, in addition to a not immediately available, but only imminent power requirement is evaluated, resulting from the prediction of this future power demand, a relationship for driving the travel drive. In principle, of course, there is the risk of a misinterpretation, if, for example, a position that is actually typical for a certain future performance requirement or a typical adjustment of the work or attachment for this purpose has an untypical cause. Nevertheless, at least with a certain probability, a future power requirement, in particular a future torque requirement, can be derived from a specific position of the work implement or attachment of the mobile work machine or from the adjustment of the work implement or attachment to a specific position.

For example, according to a development of the preceding embodiment, the mobile work machine may be a wheel loader, in particular a loader for underground mining, and the detection of the current state may comprise at least detecting a position and / or an adjustment of a bucket of the wheel loader. The term wheel loader is not limited to a vehicle with wheels to understand, but may also include crawler loaders or tracked loaders and the like vehicles. Especially with a wheel loader, in particular the movement or position of the blade of a wheel loader can be a reliable indication of an imminent change in the power requirement to the gearbox of the wheel loader.

For example, wheel loaders and in particular loaders in underground mining are often used to pick up debris with the shovel, to transport it to another location and to dump it there. Because the blade is only a limited Volume can accommodate and possibly continuously new heap accumulates, the wheel loader usually returns then to again take up heap, to transport to the other place and distribute there. During empty travel, the blade is typically raised to avoid contact with the ground. Shortly before reaching the pile but the blade is lowered to retract with lowered blade in the heap. Based on this lowering of the blade can therefore be determined that the retraction of the wheel loader is imminent in the heap, which is then accompanied by a sudden change in the power requirements of the drive.

For since the empty drive should be as quick as possible, while high speeds are required at relatively low torques. In contrast, the retraction into the heap at a significantly reduced speed, but requires much higher forces. By such an abrupt change from high to low speeds and from low to high torques, the drive train and the drive motor of the mobile machine are heavily loaded. At the same time, as quickly as possible, in particular by a change of driving range, the abruptly changed power requirement must be reacted. It is therefore expedient if the travel drive is already anticipated shortly before entering the heap in anticipation of the expected change in the power requirement, to protect the drive train and the drive motor of the mobile machine and to accelerate the adaptation to the changed power requirement.

In particular, both in wheel loaders as well as in other mobile machines, a change of driving range may already be made, initiated or at least prepared for a short time by an expected change in the power demand on the drive. This may include, for example, that a control pressure for actuators, by means of which a power-split transmission of the respective work machine, in particular a first power branch, connected and / or a variator of a second power branch of the transmission can be adjusted is already increased to the switching process or the Adjusting to accelerate, as the switching or adjustment must then be completed only. It can also be provided that in preparation for the closing of a clutch or a brake of the transmission whose clearance is already overcome in advance. In particular, frictional clutches or brakes or other elements of the variable torque transmission transmission may already be partially opened or closed in anticipation of the future power demand before being fully opened or closed for the actual implementation of the power request when the power request has become current become.

According to another embodiment, the mobile work machine is an agricultural vehicle, in particular a tractor, and detecting the current state comprises at least detecting a type and / or a position of an implement of the agricultural vehicle. Because of the type of each attached to the agricultural vehicle attachment can make a prediction on the work to be performed by means of such an attachment and thus on a related performance requirement. For example, in a connected plow with a plowing operation and in a connected seed drill with a sowing operation of the agricultural vehicle to be expected. The concrete control of the traction drive for such an implement-specific operation can be triggered, for example, thereby anticipating that the respective attachment is adjusted to a working position. Alternatively or additionally, the prediction may also include location data acquired, in particular by means of GPS, whereby e.g. known information about the location and size of a field to be processed can be considered. In this way, the traction drive of a tractor to which a plow is connected, automatically and predictively based on the detected attachment type and the detected location of the tractor are controlled such that it optimally Asked upon reaching the field to be plowed in terms of the plowing Performance requirement is adjusted.

According to a further advantageous embodiment, the mobile work machine is a transport device, in particular a dump truck, and the detection of the current state comprises at least the detection of a loading state of the transport device. About sensors can be detected about the weight of the load of the transport device and concluded therefrom on the total weight of the transport device. On the basis of the detected information and possibly further parameters, a prediction can then be made about the power requirement to be expected during a journey of the transport device loaded in this way, and the travel drive can advantageously be adapted accordingly, in particular with regard to an efficient driving style.

According to a further advantageous embodiment, the mobile work machine is an emergency vehicle and the detection of the current state comprises at least detecting the presence of an insert, in particular based on the detection of an operating state of a blue light of the emergency vehicle. For example, in an emergency vehicle with blue light from an off blue light can be concluded that there is no use and the emergency vehicle should therefore be operated in a consumption-optimized manner, whereas it can be concluded from a switched on blue light that an application is present and the emergency vehicle in a more dynamic Way to be operated. Therefore, as a result of a detected switching on of the blue light, a prediction about an imminent power requirement corresponding to a dynamic driving style can be made and the travel drive of the emergency vehicle can be automatically adjusted with regard to this driving style.

According to a further advantageous embodiment, the detection of the current state comprises at least the detection of the location, the position, the acceleration and / or a rotational speed of the mobile work machine or of a part of the mobile work machine located outside the engine and the transmission. In a similar way as the position of a blade can be an indication of the imminent entry into a pile, for example, the reaching of a specific location, where, for example, a working and / or attachment of the mobile working machine is used, is an indication be responsive to a change in operating mode, such as from a transport mode to a work mode, of the mobile work machine associated with a changed power demand so that a prediction of an upcoming future power request may be derived from this context. Similarly, instead of or in addition to the location, the location, e.g. the inclination, the acceleration and / or a speed from which also the speed of the mobile work machine can be derived are taken into account as parameters for the prediction.

The prediction is typically more reliable as more and more parameters enter the sensed current state, from which a future power demand or at least some probability of one or more possible future power demands can be derived. In this respect, it is further preferred if the detection of the current state comprises the detection of at least two, in particular at least three, different parameters of the mobile work machine.

According to a further advantageous embodiment, the method further comprises comparing the detected current state with a stored set of states, each associated with at least one future power request, and taking into account the result of the comparison for said meeting of the prediction. In principle, the sentence may also comprise only one stored state. Preferably, however, the set comprises a plurality of stored states that can be used as a reference for the detected current state. For the comparison, it can then be checked whether the current state completely corresponds to one of the stored states, or else only whether the current state is at least similar to one of the stored states, in particular within the framework of a threshold and / or probability consideration. If this is the case, then the future power request associated with this stored state can then be determined as a prediction.

The named sentence can preferably be formed and / or supplemented by teaching in one or more states and in each case one future power request assigned to the respective state. For example, it can be provided that a user of the mobile work machine can manually initiate such teaching, whereupon a current state and a, in particular within a predetermined or predeterminable time window, subsequent change in power demand to the drive are detected and stored in the sentence. In this way, the control of the traction drive can recognize a state so to speak, and determine the expected future power requirement based on the stored assignment in order to subsequently drive the traction drive in a corresponding manner in a predictive manner.

According to a preferred embodiment, the method further comprises identifying a repetitive pattern taking into account a time sequence of respective detected current states, and taking into account the identified repetitive pattern for said meeting of the prediction. In this embodiment, therefore, not only the current state is taken into account, but a whole sequence of such states, ie, in addition to the current state, also states which were up-to-date at an earlier point in time and have been detected. This makes it possible to recognize, in the sequence, patterns according to which states repeat in the same or at least a similar way. In addition, if such a repetitive pattern could be identified and, in addition, a specific change in the power request to the propulsion system occurred at a particular point in the pattern during a previous pass, preferably at several, in particular all previous, runs of the repetitive pattern at a particular location of the pattern, this indicates that that at a renewed Passing the pattern at the appropriate location will be the same change in the power request again. This relationship can thus be used to make a corresponding prediction of the expected power requirement and to anticipate the propulsion drive with regard to the power requirement.

If it is provided that repetitive patterns are identified autonomously in the sequence of detected current states, the method can thus advantageously be self-learning. After the mobile work machine has passed through a certain sequence of states several times, reliable predictions about respective changes in the power requirement to the travel drive can be made on further runs.

This is particularly useful for mobile work machines that are used to run in regular cycles of ongoing work. For example, a construction machine can be used for loading and transporting a good from a first to a second location, whereby different performance requirements are placed on the traction drive when loading, transporting, unloading and / or returning. These repeated successive operations and the respective performance requirements can be determined, for example, directly from e.g. detected by GPS respective location and / or speed profiles of the mobile work machine, are automatically detected, so that in the sequence of data thus acquired a repetitive pattern can be identified, which can then be considered for the prediction of future performance requirements. If the same work machine is still used for another purpose, for which a different state sequence is repeated, a repetitive pattern can be automatically recognized in the state sequence and used for the anticipatory control of the travel drive. In this way, advantageously, an automatic adaptability of the controller to different workflows is realized.

In this context, according to an advantageous development, it is provided that said meeting comprises the prediction that, based on the detected current state, a current position within the identified repetitive pattern is determined that for a subsequent position following the current position of the identified repetitive pattern determining a requested or requested power at a preceding cycle of the identified repetitive pattern, and deriving a future power demand from the power thus determined to disable the travel drive in response to said future power request. The distance of the sequential position from the current position corresponds for example to less than 50%, in particular at most 30%, preferably at most 20% and particularly preferably at most 10% of a cycle of the identified repetitive pattern.

In connection with a chronological sequence of detected current conditions, in particular in the context of repeatedly performed work cycles, it may also be appropriate not to adapt the travel drive or at least not only to a pattern identified therein, but (also) to adapt to the respective driver of the mobile machine. In this respect, an embodiment is advantageous in which it is provided that a driving style is identified on the basis of a temporal sequence of respective detected current states, in particular a sequence which is based on repeatedly executed working cycles, and taken into account for making the prediction about a future power requirement. The driving style can be identified, in particular, by means of operations of the working machine that are carried out manually by the respective driver, wherein preferably at least those operations are taken into account, which are carried out in successive working cycles at at least approximately the same point, so that a type of vehicle is provided which is typical for a particular driver Derive actuation of the working machine. The driving style can be defined individually for each driver. However, it is also conceivable that the respective driver is assigned a driving style from a predefined set of different driving styles, namely in each case that driving style which has the greatest correspondence with the detected driving style of the driver. Thus, the driving style of the respective current driver can be taken into account for the forecasts of future power requirements in order to achieve driver-specific optimized control of the travel drive.

The object of the invention is further achieved by a travel drive with a drive motor, in particular an internal combustion engine, a transmission which is designed to output a drive torque output by the drive motor continuously variably modified, and a control device which is adapted to the inventive method, in particular, a method according to at least one of the embodiments described above, perform. In addition, the object of the invention is also achieved by a power-split transmission with a first power branch and a second power branch, wherein the first power branch has a fixed ratio or between a plurality of fixed ratios switchable and wherein the second power branch has an adjustable variator on the translation of second power branch is infinitely variable. In this case, the transmission between different driving ranges is switchable, in each of which by adjusting the variator, the total ratio of the transmission is infinitely variable within a transmission range associated with the respective driving range. Furthermore, the transmission has a control device which is designed to carry out the method according to the invention, in particular a method according to at least one of the embodiments described above. The advantages of this traction drive and this power-split transmission arise in each case in a corresponding manner as for the respective embodiment of the executed by the control device of the traction drive or the power-split transmission method.

• 1 zeigt in schematischer Darstellung den Antriebsstrang einer mobilen Arbeitsmaschine mit einem leistungsverzweigten Getriebe, das gemäß einer Ausführungsform des erfindungsgemäßen Verfahrens angesteuert wird.

The invention will be further explained by way of example only with reference to the figure.

• 1 shows a schematic representation of the drive train of a mobile machine with a power-split transmission, which is controlled according to an embodiment of the method according to the invention.

From the mobile work machine 11 are in the simplistic schematic representation of the 1 a first axis 13 and a second axis 15 shown, each two wheels 17 as well as a differential 19 exhibit. The second axis 15 is doing by a drive motor 21 the mobile work machine 11 driven, whereas the first axis 13 not driven directly. That of the drive motor 21 Output torque is transmitted via a gearbox 23 and optionally other elements of the drive train of the mobile work machine 11 on the differential 19 the second axis 15 transferred and before there on the two wheels 17 distributed. The drive motor 21 and the gearbox 23 form a traction drive 24 the mobile work machine 11 ,

In the transmission 23 it is a power-split transmission with a first power branch 25 and a second power branch 27 , about the respective shares of the gearbox 23 incoming power can be transmitted. In this case, the first power branch 25 several switching stages, each with a different fixed ratio, between which can be switched in the manner of a gearbox. By providing a Reversierstufe also a reversal of the direction of rotation is possible. The second power branch 27 includes an adjustable variator 29 , about which the translation of the second power branch 27 at least substantially continuously variable.

The one of the first power branch 25 transmitted power component and that of the second power branch 27 transmitted power component by means of a summation element 31 merged at the in 1 shown embodiment is designed as a planetary gear. The aggregated total power is provided by the transmission 23 to the differential 19 the second axis 15 output.

The gear 23 is switchable between different driving ranges, which is associated with a respective translation range and in particular by the in the first power branch 25 each set fixed translation differ. In this case, the first power branch 25 also be interruptible, so that the power only through the second power branch 27 is transmitted. In principle, it may also be possible, the transmission 23 to switch such that power only through the second power branch 27 is transmitted. Within the transmission range assigned to a respective driving range, the overall transmission ratio can be adjusted by adjusting the variator 29 at least substantially steplessly changed.

In this way, not only the drive motor 21 , for example, by adjusting its output speed, but also the transmission 23 by switching between the driving ranges, in particular by switching the first power branch 25 , as well as by adjusting the variator 29 of the second power branch 31 be adapted to respective performance requirements, in particular torque request, which, for example, depending on a current usage of the mobile machine 11 (eg fast or slow travel, standstill or work operation) to the traction drive 24 be put. As switchable or adjustable elements, the gearbox 23 in particular clutches or brakes, for example, for switching between the fixed ratios of the first power branch 25 and / or the summation element 31 are provided, and / or adjustable Hydrostaten on, for example, as a pump or motor of a hydrostatic variator 29 act.

For controlling the drive motor 21 as well as the transmission 23 , in particular the switchable or adjustable elements of the transmission 23 , is a control device 33 provided, which is adapted to the traction drive 24 to drive according to an embodiment of the method according to the invention. Adjusting the drive motor 21 , the switching of the first power branch 25 , adjusting the variator 29 as well as other switching of the gearbox 23 through the control device 33 be in 1 by respective ones of the control device 33 outgoing arrows symbolizes.

The activation of the travel drive 24 takes place in response to a prediction about a future power requirement, in particular a future torque request, to the traction drive 24 wherein the prediction is made considering at least one detected current state. The current state outside the travel drive is recorded 24 among other things by means of a sensor 35 who works on the mobile work machine 11 is provided. At the sensor 35 For example, it is a GPS sensor for detecting the current location of the mobile work machine 11 , In principle, however, one or more other types of sensors can alternatively or additionally be used 35 be provided, of which the control device 33 Get information about the current state. The current state usually includes information about the mobile work machine 11 , He can also provide information about conditions outside the mobile work machine 11 , eg about a condition of the roadway or about weather conditions. In addition, the detection of the current state includes that the position or the adjustment of a work or attachment 37 the mobile work machine 11 is detected, which is, for example, the blade of a wheel loader.

As in 1 symbolized by arrows are those from the one or more sensors 35 information collected and information on the position or adjustment of the implement or attachment 37 in the control device 33 together and define together a current state, by the control device 33 is used as the basis for predicting the future performance requirement. Based on this prediction, the control device 33 then the traction drive 24 anticipatory, in particular to prepare for an expected significant change in the performance requirement or already initiate this change. In this way, an advantageous improvement in the switching speed and dynamics of the traction drive 24 as well as a protection of the traction drive 24 be achieved before sudden load changes.

LIST OF REFERENCE NUMBERS

11

mobile work machine

13

first axis

15

second axis

17

wheel

19

differential

21

drive motor

23

transmission

24

traction drive

25

first power branch

27

second power branch

29

variator

31

summing

33

control device

35

sensor

37

Work or attachment

Claims (22)

Method for controlling a traction drive (24) provided in a mobile work machine (11), comprising a drive motor (21), in particular an internal combustion engine, and a transmission (23) designed to generate a drive torque output by the drive motor (21) continuously variably modified, the method comprises that at least one current state outside the travel drive (24) is detected, which does not correspond to an immediate power requirement, that a prediction about a future power requirement is made, taking into account the detected current state, and that in dependence on the prediction of the traction drive (24) is adjusted, in particular the drive motor (21), the transmission (23) and optionally an auxiliary motor are adjusted. Method according to Claim 1 wherein the transmission (23) is adapted to summing the drive torque output by the drive motor (21) with a drive torque output by an auxiliary motor, in particular an electric motor, wherein the auxiliary motor and / or the summation is / are infinitely variable. Method according to Claim 1 or 2 wherein the travel drive (24) as the said transmission (23) comprises a power-split transmission (23) having a first power branch (25) and a second power branch (27), wherein the first power branch (25) has a fixed ratio or between several wherein the second power branch (27) has an adjustable variator (29), via which the ratio of the second power branch (27) is continuously variable, wherein the transmission (23) is switchable between different driving ranges, in each of which Adjusting the variator (29), the overall ratio of the transmission (23) is infinitely variable within a transmission range associated with the respective driving range, and wherein the method comprises in that, as a function of the prediction, the drive motor (21) is adjusted, the transmission (23) is switched and the variator (29) is adjusted. Method according to at least one of the preceding claims, wherein the position and the adjustment of an accelerator pedal, a shift lever or a shift knob, preferably the position and the adjustment of each manually operated control element that serves the drive motor (21), optionally the auxiliary motor or to change or specify an operating mode of the transmission (23) directly, each corresponding to an immediate power demand. Method according to at least one of the preceding claims, wherein the transmission (23) has a control device (33) which is designed to adjust the travel drive (24) in dependence on the prediction. Method according to Claim 5 wherein the control device (33) receives the detected current state as at least one parameter provided to the control device (33) via a CAN bus of the mobile work machine (11). Method according to at least one of the preceding claims, wherein the current state is detected by means of at least one sensor (35) provided outside the drive motor (21) and the transmission (23), in particular outside the entire travel drive (24) on the mobile work machine (11) becomes. Method according to at least one of the preceding claims, wherein the detection of the current state comprises at least the detection of a type, a position and / or an adjustment of a working device (37) and / or an attachment (37) of the mobile work machine (11). Method according to Claim 8 wherein the mobile work machine (11) is a wheel loader, in particular a loader, and detecting the current state comprises at least detecting a position and / or an adjustment of a blade of the wheel loader. Method according to Claim 8 wherein the mobile work machine (11) is an agricultural vehicle, in particular a tractor, and detecting the current state comprises at least detecting a type and / or a position of an implement of the agricultural vehicle. Method according to Claim 8 wherein the mobile work machine (11) is a transport device, in particular a dump truck, and detecting the current state comprises at least detecting a loading state of the transport device. Method according to Claim 8 wherein the mobile work machine (11) is an emergency vehicle and the detection of the current state comprises at least detecting the presence of an insert, in particular based on detecting an operating state of a blue light of the emergency vehicle. Method according to at least one of the preceding claims, wherein the detection of the current state comprises at least the detection of the location, the position, the acceleration and / or a rotational speed of the mobile work machine (11) or a part of the mobile work machine (11). Method according to at least one of the preceding claims, wherein the detection of the current state comprises the detection of at least two, in particular at least three, different parameters of the mobile work machine (11). Method according to at least one of the preceding claims, the method further comprising that the detected current state is compared with a stored set of states each associated with at least one future power request, and that for the said meeting of the prediction the result of the comparison is taken into account. Method according to Claim 15 wherein said sentence may be formed and / or supplemented by training one or more states and each associated future performance request. Method according to at least one of the preceding claims, wherein the method further comprises that a repetitive pattern is identified taking into account a time sequence of respective detected current states, and that for said meeting of the prediction the identified repetitive pattern is taken into account. Method according to Claim 17 , Wherein location and / or speed profiles of the mobile work machine (11) are considered for the identification of the repetitive pattern as a time sequence of respective detected current states. Method according to Claim 17 or 18 wherein said meeting comprises the prediction that a current position within the identified repetitive pattern is determined from the detected current state, in that, for a following position of the identified repetitive pattern following the current position, a power delivered or requested in a preceding cycle of the identified repetitive pattern at the follower position is determined, and from the power thus determined a future power demand is derived, in dependence thereon future power requirement to adjust the travel drive (24). Method according to at least one of the preceding claims, the method further comprising in that a driving style is identified on the basis of a time sequence of respective detected current states, in particular a sequence which is based on repeatedly executed operating cycles, and taken into account for making the prediction about a future power requirement. Traveling drive with a drive motor (21), in particular an internal combustion engine, a transmission (23) which is adapted to output a drive torque output from the drive motor (21) continuously variably modified, and a control device (33) which is adapted to a Method according to at least one of the preceding claims. A power split transmission (23) having a first power branch (25) and a second power branch (27), wherein the first power branch (25) has a fixed ratio or is switchable between a plurality of fixed ratios, and wherein the second power branch (27) comprises an adjustable variator (27). 29), via which the translation of the second power branch is continuously variable, wherein the transmission (23) is switchable between different driving ranges, in each of which by adjusting the variator (29) the overall ratio of the transmission (23) continuously within a respective driving range associated transmission range is variable, and wherein the transmission (23) comprises a control device (33) which is adapted to a method according to at least one of Claims 1 to 20 perform.

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