Control arrangement and method for operating a towing unit of a vehicle combination
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-08-13
Smart Images
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Abstract
Description
[0001] CONTROL ARRANGEMENT AND METHOD FOR OPERATING A TOWING UNIT OF A VEHICLE COMBINATION
[0002] TECHNICAL FIELD
[0003] The present disclosure relates in general to a method for operating a towing unit of a vehicle combination. The present disclosure also relates in general to a control arrangement configured to operate a towing unit of a vehicle combination, and to a vehicle unit comprising said control arrangement.
[0004] The present disclosure also relates in general to a computer program as well as a computer-readable medium.
[0005] BACKGROUND
[0006] The development of self-powered trailers, often also referred to as electric trailers or e-trailers in the art, is gaining a lot of interest within the industry of heavy-duty vehicles. In contrast to a conventional trailer (which is a non-motorized vehicle unit), an e-trailer comprises its own drive unit configured to provide motive torque to wheels of the trailer. Such a drive unit typically comprises at least one power unit, in the form of an electrical machine, and a transmission arrangement, which may be a single-speed or a multi-speed transmission arrangement. An e-trailer may for example comprises one or more electric drive axles, also known as e-axles. Since the e-trailer comprises its own drive unit, it can support a tractor unit (such as a tractor truck), to which the e-trailer is connected, in meetingthe desired total motive force forthe vehicle combination. This can in turn lead to improved energy efficiency of the vehicle combination. Some e-trailers may also recover electrical energy through regenerative braking and store this energy in a traction battery configured to power the drive unit. This may in turn further improve the energy efficiency of the vehicle combination.
[0007] Even though e-trailers have been developed for a while, the focus of the research has typically been on the e-trailer as such and not from the perspective of the tractor units to which the e-trailer may be connected. Moreover, the e-trailers currently available on the market have typically been developed by parties other than tractor unit manufacturers, and are in generalintended to be connectable to different tractor units. Therefore, the technology of e-trailers is a new subject for tractor unit manufacturers, and is often not integrated with tractor units. This means that a tractor unit typically has no knowledge of how an e-trailer connected thereto is controlled. In fact, a tractor unit may not even recognize that an e-trailer has been connected thereto, as opposed to a conventional trailer. This may cause issues with certain functionalities of the tractor unit, which are typically built on the premise that the only source of motive power of a vehicle combination comprising the tractor unit is the torque provided by the power unit(s) of the tractor unit. However, if the vehicle combination comprises an e-trailer (at least if not fully integrated with the tractor unit), this is no longer a fact as the vehicle combination comprises an unknown torque producer due to the drive unit of the e-trailer.
[0008] One example of a problem that may arise when an e-trailer is comprised in a vehicle combination is that the tractor unit may underestimate the total mass of the vehicle combination as a result of the additional motive power provided to the vehicle combination by the e-trailer, leading to a lower torque needed from the tractor unit compared to if the vehicle combination would have the same mass and the only source of the motive power to the vehicle combination would be provided by the tractor unit. An underestimation of the total mass of the vehicle combination may in turn e.g., lead to selection of an inappropriate start gear and / or inappropriate gear selection for low speed maneuvering, for example if the e-trailer is configured to only provide motive power above a vehicle speed threshold. An inappropriate gear selection in such situations may in turn lead to unnecessary clutch wear (if the tractor unit comprises a clutch) and / or a gear hunting behavior of the tractor unit.
[0009] Other examples of functionalities of a tractor unit that may be negatively affected when the vehicle combination comprises a non-integrated torque producer include, but are not limited to, estimation of future energy consumption of the tractor unit and smart cruise control functions.
[0010] SUMMARY
[0011] The object of the present invention is to allow for desired functionality of a towing unit of a vehicle combination even in situations where the vehicle combination may comprise a nonintegrated torque producer.
[0012] The object is achieved by the subject-matter of the appended independent claim(s).The present disclosure relates to a method, performed by a control arrangement, for operating a towing unit of a vehicle combination. The method comprises a step of monitoring experienced driving resistance of the towing unit during one or more preselected driving situations. The method further comprises a step of, based on the experienced driving resistance of the towing unit during the one or more preselected driving situations, analyzing possible residuals of a force-based reference model for the towing unit to thereby determine whether the vehicle combination comprises a non-integrated torque producer. The method further comprises a step of, when it is determined that the vehicle combination comprises a non-integrated torque producer, adjusting at least one control strategy for the towing unit and / or re-estimating an expected future energy consumption of the towing unit.
[0013] The herein described method allows for a towing unit of a vehicle combination to determine whether the vehicle combination comprises a non-integrated torque producer (e.g., a torque producer being unknown to the towing unit, being configured to be controlled according to strategies unknown to the towing unit, and / or having propelling and / or braking properties unknown to the towing unit), and adapting the operation of the towing unit in response thereto. As evident from the above, the determination of whether the vehicle combination comprises a non-integrated torque producer is performed by comparing the experienced driving resistance during one or more preselected driving situations with an expected driving resistance for the corresponding one or more preselected driving situations, said expected driving resistance being determined through usage of a force-based reference model for the towing unit. By analyzing the residuals of the force-based reference model for said one or more driving situations, it can be realized whether the vehicle combination comprises an unknown torque producer, such as in the form of an e-trailer. This is important for understanding whether e.g., the control of the towing unit needs to be adjusted to ensure a desired functionality of the towing unit. Such a functionality may be important for energy efficiency of the towing unit, performance of the towing unit, driver comfort, and / or road safety. Moreover, knowledge of whether the vehicle combination comprises a non-integrated torque producer is important when estimating future energy consumption of the towing unit, e.g. for determining an available driving range and / or route planning. In other words, by means of the herein described method, it is possible to achieve, or ensure, a desired functionality of the towing unit of a vehicle combination even in situations where the vehicle combination may comprise a non-integrated torque producer.The towing unit may comprise one or more power units, and the step of monitoring experienced driving resistance of the towing unit during one or more preselected driving situations may comprise monitoring torque output of the one or more power units of the towing unit duringthe one or more preselected driving situations. This allows for an easy and reliable determination of the experienced driving resistance of the towing unit.
[0014] The step of analyzing possible residuals of the force-based reference model for the towing unit comprises determining whether the possible residuals at least partly pertain to possible error(s) in estimation of mass and / or rolling resistance. Error(s) in estimation of mass and / or rolling resistance are likely to occur when the vehicle combination comprises a non-integrated torque producer, as the purpose of such a non-integrated torque producer is to at least partly compensate for the increased mass and / or rolling resistance of the vehicle combination resultingfrom the vehicle unit comprisingthe non-integrated torque producer. This in turn means that the towing unit may not always sense the true increase of mass and / or rolling resistance in each possible driving situation, at least not in the same way as if the vehicle unit connected to the towing unit would be e.g. a conventional trailer.
[0015] The method may further comprise a step of mapping residuals of the force-based reference model for the towing unit in dependence of different driving situations, and a step of analyzing the mapped residuals to determine a behavior of the non-integrated torque producer. An understanding of the behavior of the non-integrated torque producer (for example in which driving situations it may contribute, and to what extent it may contribute, to the total motive force) allows for better adaptations of the operation of the towing unit when the vehicle combination comprises the non-integrated torque producer.
[0016] The method may further comprise a step of, based on the determined behavior of the nonintegrated torque producer and / or the mapped residuals of the force-based reference model for the towing unit, determining one or more adjusted force-based models for the towing unit, each of the one or more adjusted force-based models being dependent on driving situation. This further improves the ability to make appropriate adjustments to the operation of the towing unit.
[0017] The above described step of adjusting at least one control strategy for the towing unit may suitably be performed based on the determined one or more adjusted force-based models for the towing unit. This ensures that the at least one control strategy for the towing unit is appropriately adjusted, and hence allows for e.g. improved performance and / or energyefficiency of the towing unit when comprised in the vehicle combination comprising a nonintegrated torque producer.
[0018] The above described step of re-estimating an expected future energy consumption of the towing unit may be performed based on the determined one or more adjusted force-based models for the towing unit. This may allow for increased accuracy in the estimation of the expected future energy consumption of the towing unit, which in turn may improve the reliability in e.g. an estimated distance to empty, determined based on the estimated expected future energy consumption, and / or allow for improved route planning for the towing unit or the vehicle combination in case such route planning is performed taking into account energy efficiency.
[0019] Additionally, or alternatively, the above described step of re-estimating an expected future energy consumption of the towing unit may comprise estimating future energy consumption of the towing unit for at least two candidate routes of the vehicle combination. In such a case, the method may further comprise a step of selecting a route from the at least two candidate routes taking into account the estimated future energy consumption of the towing unit for the at least two candidate routes. Such a selected route may for example be communicated to a driver of the towing unit through usage of a user interface, and / or be communicated to a remote systems, such as a fleet management system or the like. Alternatively, the method may in such a case comprise a step of communicatin the estimated future energy consumption of the towing unit for the at least two candidate routes to a route planning system associated with the towing unit, and / or, through usage of a user interface, to a driver of the towing unit. This allows the route planning system and / or the driver of the towing unit to select an appropriate route.
[0020] The step of adjusting at least one control strategy for the towing unit may comprise adjusting a gear selection strategy for the towing unit. Thereby, it may be ensured that a gear, suitable under the prevailing circumstances, is selected. This in turn ensures that the towing unit is operated in an energy efficient manner, with a desirable performance, and behaves as may be expected by a possible driver of the towing unit.
[0021] Additionally, or alternatively, the step of adjusting at least one control strategy for the towing unit may comprise adjusting a control strategy for braking of the towing unit and / or the vehicle combination. This may in turn improve energy efficiency during driving, improve road safety, ensure desirable driver comfort, and improve the performance of the towing unit. Suitably, thestep of adjusting at least one control strategy for the towing unit may comprise adjusting a control strategy for auxiliary braking of the towing unit.
[0022] Additionally, or alternatively, the step of adjusting at least one control strategy for the towing unit may comprise adjusting a cruise control strategy, such as a predictive cruise control strategy, for the towing unit. This may in turn improve energy efficiency during driving, ensure desirable driver comfort, and improve the performance of the towing unit.
[0023] The present disclosure further relates to a control arrangement configured to operate a towing unit of a vehicle combination. The control arrangement is configured to monitor experienced driving resistance of the towing unit during one or more preselected driving situations. The control arrangement is further configured to, based on the experienced driving resistance of the towing unit duringthe one or more preselected driving situations, analyze possible residuals of a force-based reference model for the towing unit to thereby determine whether the vehicle combination comprises a non-integrated torque producer. Moreover, the control arrangement is configured to, when it is determined that the vehicle combination comprises a non-integrated torque producer, adjust at least one control strategy for the towing unit and / or re-estimate an expected future energy consumption of the towing unit.
[0024] The control arrangement provides the same advantages as described above with regard to the herein described method for operating a towing unit of a vehicle combination.
[0025] The control arrangement may further be configured to map residuals of the force-based reference model for the towing unit in dependence of different driving situations, and analyze the mapped residuals to determine a behavior of the non-integrated torque producer.
[0026] The control arrangement may further be configured to, based on the determined behavior of the non-integrated torque producer and / or the mapped residuals of the force-based reference model for the towing unit, determine one or more adjusted force-based models for the towing unit, each of the one more adjusted force-based models being dependent on driving situation.
[0027] The present disclosure also relates to a computer program comprising instructions which, when executed by a control arrangement, cause the control arrangement to perform the above described method for operating a towing unit of a vehicle combination.Moreover, the present disclosure relates to a computer-readable medium comprising instructions which, when executed by a control arrangement, cause the control arrangement to perform the method for operating a towing unit of a vehicle combination as described above.
[0028] The present disclosure also relates to a vehicle unit configured to, when comprised in a vehicle combination, act as a towing unitfor a vehicle combination, said vehicle unit comprisingthe above described control arrangement configured to operate a towing unit of a vehicle combination. Such a vehicle combination may be a heavy vehicle.
[0029] BRIEF DESCRIPTION OF DRAWINGS
[0030] Fig. 1 illustrates a side view of an example of a vehicle combination,
[0031] Fig. 2 schematically illustrates an example of a vehicle combination,
[0032] Fig. 3 represents a flowchart schematically illustrating one exemplifying embodiment of the herein described method for operating a towing unit of a vehicle combination, and
[0033] Fig. 4 schematically illustrates a device that may comprise, consist of, or be comprised in the herein described control arrangement configured to operate a towing unit of a vehicle combination.
[0034] DETAILED DESCRIPTION
[0035] The invention will be described in more detail below with reference to exemplifying embodiments and the accompanying drawings. The invention is however not limited to the exemplifying embodiments discussed and / or shown in the drawings, but may be varied within the scope of the appended 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.A vehicle is in the present disclosure considered to mean any means that may be used for transporting people and / or cargo. A vehicle may consist of a single vehicle unit. Examples of a vehicle consisting of a single vehicle unit include a car, a rigid truck, a tractor truck, a bus, a self-powered trailer, or a self-powered dolly, but are not limited thereto. Alternatively, a vehicle may constitute a vehicle combination comprising at least two vehicle units which are physically linked when travelling. A vehicle combination may be a vehicle comprising a towing vehicle unit and at least one trailing vehicle unit. Examples of vehicle combinations include a semi-trailer truck, a rigid truck pulling a semitrailer using a dolly, a vehicle train comprising a rigid truck and one or more trailers, or a self-powered dolly pulling a semitrailer or a trailer, but are not limited thereto.
[0036] The terms “towing unit” and “towing vehicle unit” are used interchangeably herein, and are considered to mean a vehicle unit that, when comprised in a vehicle combination, constitutes the leading vehicle unit of the vehicle combination as seen in the primary direction of travel of said vehicle combination (in other words, as seen in the forward moving direction). A towing unit may typically be a tractor unit, such as a tractor truck or a rigid truck, to which at least one trailing unit may be connected. Alternatively, a towing unit may be a self-powered dolly in such cases where said self-powered dolly acts as the leading vehicle unit of a vehicle combination, for example when towing a semitrailer of its own without the use of a tractor truck.
[0037] A trailing unit is a vehicle unit which, when comprised in a vehicle combination, is directly physically connected to the leading vehicle unit or connected to the leading vehicle unit via another vehicle unit. Thus, a trailing unit may for example be a trailer or a dolly. It should here be noted that such a trailer or dolly may be a self-powered trailer or dolly, or may be a conventional, non-motorized, trailer or dolly.
[0038] In the present disclosure, the term “driver” is intended to mean a human controlling a vehicle or a vehicle unit (such as a towing unit), and is thus intended to encompass both a driver present onboard a vehicle (such as a towing unit) as well as a human controlling the vehicle remotely, such as from a control center or the like.
[0039] As is well known in the art, driving resistance of a vehicle (or a vehicle unit, such as a towing unit) constitutes the resistance against said vehicle’s movement in the direction of its longitudinal axis, and is a result of the forces counteractingthe vehicle’s movement. The driving resistance of a towing unit of a vehicle combination inherently corresponds to the drivingresistance of vehicle combination as such, at least unless the vehicle combination comprises an unknown torque producer.
[0040] Moreover, in the present disclosure, the term “non-integrated torque producer” is considered to mean a torque producer, such as a drive unit of an e-trailer, that is not fully integrated with the vehicle combination and thus not fully integrated with the towing unit of the vehicle combination. In other words, a non-integrated torque producer is considered to mean a torque producer whose presence, control strategies, and / or properties / capabilities are unknown to the towing unit of the vehicle combination, such as due to a lack of communication from the nonintegrated torque producer to the towing unit. This also inherently means that a non-integrated torque producer is a torque producer that may not be controlled by the towing unit of the vehicle combination. It should however be noted that a controller of a non-integrated torque producer of the vehicle combination may be configured to read information or requests communicated from the towing unit, e.g. via a CAN bus, in the same way as a conventional, non-motorized, trailer can, without departing from the present disclosure. For example, a controller of a nonintegrated torque producer may be configured to read brake requests from the towing unit.
[0041] The present disclosure relates to a method for operating a towing unit of a vehicle combination. The method is performed by a control arrangement configured therefore. The method comprises a step of monitoring experienced driving resistance of the towing unit during one or more preselected driving situations for the vehicle combination. The method further comprises a step of, based on the experienced driving resistance of the towing unit during the one or more preselected driving situations, analyzing possible residuals of a force-based reference model for driving resistance of the towing unit to thereby determine whether the vehicle combination comprises a non-integrated torque producer. The method further comprises a step of, when it is determined that the vehicle combination comprises a non-integrated torque producer, adjusting at least one control strategy for the towing unit. Alternatively, or additionally, the method comprises a step of re-estimating an expected future energy consumption of the towing unit when it is determined that the vehicle combination comprises a non-integrated torque producer.
[0042] It should be noted that, when the herein described method for operating a towing unit of a vehicle combination comprises the step of adjusting at least one control strategy for the towing unit, the method may alternatively be described as a method for controlling a towing unit of a vehicle combination. However, when the herein described method does not comprise the stepof adjusting at least one control strategy for the towing unit, the method may alternatively be described as a method for estimating future energy consumption of the towing unit of the vehicle combination; or, more specifically, a method for estimating future energy consumption of the towing unit of the vehicle combination for the purpose of estimating a distance to empty and / or route planning.
[0043] Suitably, the method comprises monitoring experienced driving resistance of the towing unit during a plurality of different preselected driving situations, and, based on the experienced driving resistance of the towing unit during the plurality of different preselected driving situations, analyzing the possible residuals of the force-based reference model for the towing unit during the plurality of different preselected driving situations. Thereby, the analysis may be improved so as to facilitate determining whether the vehicle combination comprises a nonintegrated torque producer. The reason therefore is that the non-integrated torque producer may, for example, be configured to provide torque in some driving situations whereas in one or more other driving situations it is not configured to provide any torque, and thereby no power to the vehicle combination, or it may be configured to provide different amounts of torque in different driving situations.
[0044] The above mentioned one or more preselected driving situations may be differentiated from each other in terms of whetherthe towing unit (and thus also the vehicle combination) is accelerated or braked, driven uphill or downhill, at certain travelling speed or travelling speed interval, during coasting or non-coasting, and / or when set into motion from standstill or when already being in motion. A preselected driving situation may alternatively be described as a preselected driving condition scenario, and may be defined by different boundary driving conditions.
[0045] It is well known that force-based models may be used to estimate driving resistance of a vehicle, such as a towing unit or a vehicle combination comprising a towing unit and one or more trailing units. One example of a force-based reference model for a vehicle is given below in Equation 1 :
[0046] F_Trac = F_acc + F_incl + F_air + F_roll (Eq. 1)wherein F_Trac is the total tractive force, F_acc is the acceleration force, F_incl is the force resulting from road inclination, F_air is the aerodynamic drag force, and F_roll is the rolling resistance force.
[0047] In Equation 1 above,
[0048] F_acc = m*a (Eq. 2)
[0049] FJncl = m*g*sin(a) (Eq. 3)
[0050] wherein m represents the mass of the vehicle, a represents the wheel acceleration, g represents the gravitational force, and a represents the road inclination (in radians).
[0051] Thus, Equation 1 may be rewritten into Equation 4:
[0052] F_Trac = m * (a + g* sin(a)) + F_air + F_roll (Eq. 4)
[0053] A towing unit of a vehicle combination may comprise one or more power units. An experienced driving resistance of the towing unit may be determined through consideration of the torque output of said one or more power units since force provided to the towing unit (and thus also to the vehicle combination) is dependent thereof. Described differently, a determined torque may be compared to a model of torque, which in turn is dependent of the force-based reference model. Therefore, the step of monitoring experienced driving resistance of the towing unit during one or more preselected driving situations may comprise monitoring torque output of the one or more power units of the towing unit during said one or more preselected driving situations.
[0054] Furthermore, the step of analyzing possible residuals of the force-based reference model for the towing unit may comprise determining whether the possible residuals at least partly pertain to possible error(s) in estimation of mass and / or rolling resistance. Error(s) in estimation of mass and / or rolling resistance are likely to occur when the vehicle combination comprises a nonintegrated torque producer, as the purpose of such a non-integrated torque producer is to at least partly compensate for the increased mass and / or rolling resistance of the vehicle combination resulting from the vehicle unit comprising the non-integrated torque producer. This in turn means that the towing unit may not always sense the true increase of mass and / or rolling resistance in each possible driving situation, at least not in the same way as if the vehicle unit connected to the towing unit would be e.g. a conventional trailer. In contrast, for example anypossible differences in air resistance in case the towing unit is connected to a conventional trailer compared to a trailer comprising an unknown torque producer are typically neglectable.
[0055] The herein described method for operating a towing unit of a vehicle combination may further comprise a step of mapping residuals of the force-based reference model for the towing unit in dependence of different driving situations, and a step of analyzing the mapped residuals to determine a behavior of the non-integrated torque producer. The control strategy of an e-trailer is typically different depending on the driving situations, such as depending on if the towing unit is braking, accelerating, set into motion from standstill, or coasting (in neutral, or with open clutch, if a clutch is present). Therefore, in order to determine a behavior of the non-integrated torque producer, it is advisable to consider different driving situations separately. Byway of example only, some e-trailers are not configured to be regeneratively braked, and / or may only be configured to contribute to the motive power to the vehicle combination at travelling speeds above a preselected threshold.
[0056] The method may further comprise a step of, based on the determined behavior of the nonintegrated torque producer and / or the mapped residuals of the force-based reference model for the towing unit, determining one or more adjusted force-based models for the towing unit, wherein each of said one or more adjusted force-based models is dependent on driving situation.
[0057] For example, an adjusted force-based model, applicable during acceleration, may be given by Equation 5:
[0058] F_Trac = m *(a + g* sin(a))*X_TAcc + F_air + F_roll_ref + F_resistance_TAcc (Eq. 5)
[0059] In Equation 5, X_TAcc represents a scaling factor, applicable to the driving situation of acceleration, as a result of the non-integrated torque producer providing motive force compensating for some of the total mass of the vehicle combination. Moreover, F_roll_ref represents a reference rolling resistance force (which, for example, may correspond to an expected rolling resistance force of the vehicle combination in case a non-integrated torque producer would be absent), and F_resistance_TAcc represents a corrective term representing a substantially non-variable force delivered by the non-integrated torque producer to adjust for its own rolling resistance, air resistance, and / or other losses resulting in increased resistance force.An example of an adjusted force-based model, applicable during braking, is given by Equation 6:
[0060] F_Trac = m *(a + g* sin(a))*X_TBrake + F_air + F_roll_ref+ F_resistance_TBrake (Eq. 6)
[0061] In Equation 6, X_TBrake represents a scaling factor, applicable to the driving situation of braking, as a result of the non-integrated torque producer providing braking force to the vehicle combination, e.g. due to regenerative braking of the trailing unit. Moreover, F_roll_ref represents a reference rolling resistance force (as described above with regard to Equation 5), and F_resistance_TBrake represents a corrective term representing a substantially non-variable force delivered by the non-integrated torque producer to adjust for its loses (and / or gains) in situations where the vehicle combination is braked.
[0062] As previously mentioned, the herein described method may comprise, when it is determined that the vehicle combination comprises a non-integrated torque producer, adjusting at least one control strategy for the towing unit. Said step of adjusting at least one control strategy may suitably be performed based on the determined one or more adjusted force-based models for the towing unit. As already mentioned above, each of the one or more adjusted force-based models for the towing unit is dependent on driving situation. Therefore, an adjusted control strategy for the towing unit will also inherently depend on the driving situation prevailing when the adjusted control strategy for the towing unit is utilized. This in turn means that the functionality of the towing unit is adapted to the circumstances, which in turn ensures that the towing unit is operated in a favorable way.
[0063] Similarly, in case the method comprises a step of re-estimating an expected future energy consumption of the towing unit, this step may suitably be performed based on the determined one or more adjusted force-based models. Described differently, said one or more determined adjusted force-based models may be taken into consideration when re-estimating future energy consumption of the towing unit due to the vehicle combination comprising a non-integrated torque producer.
[0064] It should here be noted that in cases where the herein described method does not comprise the step of determining one or more adjusted force-based models for the towing unit, the steps of adjusting at least one control strategy for the towing unit and / or re-estimating an expected future energy consumption of the towing unit may instead be performed based on instructionscommunicated to / retrieved by the control arrangement performing the method. Such instructions may be provided by a system (such as a server-based system) remote from the towing unit and be based on historical data of the towing unit when being comprised in a vehicle combination comprising a non-integrated torque producer. Additionally, or alternatively, such adjusted force-based model(s) dependent of driving situation may already be available to the control arrangement in view of being previously determined by the control arrangement, for example based on historical data.
[0065] The step of re-estimating an expected future energy consumption of the towing unit may comprise estimating future energy consumption of the towing unit for at least two candidate routes of the vehicle combination. In such a case, the method may further comprise a step of selecting a route from the at least two candidate routes taking into account the estimated future energy consumption of the towing unit for the at least two candidate routes. The selected route may thereafter be communicated to e.g., a driver of the towing unit via a user interface in accordance with previously known techniques therefore. Alternatively, the method may comprise a step of communicating the estimated future energy consumption of the towing unit for the at least two candidate routes to a route planning system associated with the towing unit, and / or, through usage of a user interface, to a driver of the towing unit. In such a case, the route planning may be made by the route planning system and / or the driver of the towing unit, as opposed to the herein described control arrangement. When future energy consumption of the towing unit is estimated for a plurality of candidate routes, it may for example be realized that routes that would not be able to be taken if the vehicle combination did not comprise the nonintegrated torque producer are now a plausible option due to the presence of the non-integrated torque producer. Moreover, it is possible to avoid routes which would result in the nonintegrated torque producer not being able to sufficiently contribute to improved energy consumption of the towing unit or desired motive / braking torque contribution.
[0066] The above described step of adjusting at least one control strategy for the towing unit may comprise adjusting a gear selection strategy for the towing unit. For example, the method may comprise adjusting strategy for selection of starting gear and / or selection of gear for low speed maneuvering (such as at travelling speeds below 20 km / h, or below 15 km / h). By way of example only, the towing unit may for example be configured to utilize a default strategy for selection of starting gear based on a mass estimation, wherein said mass estimation may be derived during driving at higher travelling speeds. If the mass estimation has been made while the nonintegrated torque producer provides motive power to the vehicle combination, the towing unitmay have underestimated the true mass of the vehicle combination. This may in turn lead to an inappropriate starting gear being selected in case the default gear selection strategy is used. Therefore, in accordance with an adjusted strategy for selection of starting gear, the starting gear may instead be selected conservatively. Thereby, the risk of clutch wear (if a clutch is comprised in the towing unit) may be reduced and / or the starting experience be improved. It should here be noted that a gear selection strategy to be adjusted in accordance with the herein described method is not limited to a strategy for selection of starting gear or selection of gear for low speed maneuvering. In other words, the method may additionally, or alternatively, comprising adjusting a gear selection strategy pertaining to selection of gear at higher travelling speeds.
[0067] The step of adjusting at least one control strategy for the towing unit, when it is determined that the vehicle combination comprises a non-integrated torque producer, may further comprise adjusting a control strategy for coasting of the towing unit. Such a control strategyfor coasting may e.g. comprise a clutch control strategy in case of the towing unit comprising a clutch. For example, the method may comprise adjusting a strategy for when to utilize coasting during driving, wherein said coasting may be performed with a transmission arrangement of the towing unit being put in neutral and / or with open clutch.
[0068] Additionally, or alternatively, the step of adjusting at least one control strategy for the towing unit may comprise adjusting a control strategyfor braking of the towing unit and / or the vehicle combination. Such a control strategyfor braking may suitably comprise, or constitute, a control strategy for auxiliary braking of the towing unit. In general, when a towing unit is braked using only auxiliary brake(s), such as by means of a retarder, through regenerative braking, or by engine braking, a braking request is typically not communicated to a trailer (as to opposed to a situation where braking usingthe service brakes are needed). However, an e-trailer connected to the towing unit may still be configured to regeneratively brake in such situations, e.g., for the purpose of charging a traction battery of the e-trailer. This means that the vehicle combination may actually be provided with a higher total braking power than expected by the towing unit. This may in turn cause disturbances during auxiliary braking in case the control strategy of the towing unit is not adapted. In situations where the non-integrated torque producer is not configured to provide any braking power to the vehicle combination, although this may possibly be expected by the towing unit (e.g. due to historical data), there may be a risk of overrunning which can lead to a potentially hazardous situation. Therefore, it is often advisable to adjust thecontrol strategy for braking of the towing unit and / or vehicle combination is case the vehicle combination comprises a non-integrated torque producer.
[0069] Moreover, the step of adjusting at least one control strategy for the towing unit, when the vehicle combination comprises a non-integrated torque producer, may additionally or alternatively comprise adjusting one or more cruise control strategies for the towing unit. Such one or more cruise control strategies may for example be selected from the group comprising a predictive cruise control strategy, an adaptive cruise control strategy, a curve speed cruise control strategy, and a speed sign cruise control strategy. Suitably, the step of adjusting at least one control strategy for the towing unit comprises at least adjusting a predictive cruise control strategy for the towing unit. As is well known in the art, when a vehicle is controlled using a predictive cruise control system, characteristics of an upcoming road section (which may for example be determined based on geographical position of the vehicle in combination with map data, including topographic data) are used for planning a suitable driving strategy of the vehicle for said upcoming road section, and the vehicle is thereafter controlled in accordance with the selected driving strategy when travelling said road section. A predictive cruise control system can save substantial amounts of energy compared to e.g., a constant speed cruise control system, which is designed to substantially maintain a set speed. For example, in case the upcoming road section comprises an uphill followed by a downhill, the vehicle may be accelerated so as to, at the crest of the hill, have a speed which is lower than the set speed in situations where the vehicle speed may be increase during the downhill as a result of the gravitational force so as to reach the set speed. Thereby, a predictive cruise control system may avoid unnecessary energy consumption compared to a constant speed cruise control system which would accelerate the vehicle when driving said uphill to maintain the set speed as well as brake the vehicle duringthe following downhill. In case a vehicle combination comprises a nonintegrated torque producer, such a non-integrated torque producer may e.g., contribute to the motive and / or braking power provided to the vehicle combination when travelling uphill / downhill. This in turn affects the motive / braking power needed to be provided by the towing unit, and the predictive cruise control strategy for the towing unit may therefore suitably be adapted to ensure desired functionality.
[0070] The performance of the herein described method for operating a towing unit of a vehicle combination may be governed by programmed instructions. These programmed instructions may take the form of a computer program which, when executed by a computer, cause the computer to effect desired forms of control action and / or estimations. Such a computer may forexample be comprised in the control arrangement configured to operate a towing unit of a vehicle combination as described herein. A computer is in the present disclosure considered to mean any hardware or hardware / firmware device implemented using processing circuity such as, but not limited to, a processor, Central Processing Unit (CPU), a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, an applicationspecific integrated circuit, or any other device capable of electronically performing operations in a defined manner.
[0071] The above described programmed instructions, which may take the form of a computer program, may be stored on a computer-readable medium. Hence, the present disclosure also relates to a computer-readable medium storing instructions, which when executed by a computer or a control arrangement comprising the computer, cause the computer / control arrangement to carry out the herein described method for operating a towing unit of a vehicle combination. The computer-readable medium may be a non-transitory computer-readable medium, such as a tangible electronic, magnetic, optical, infrared, electromagnetic, and / or semiconductor system, apparatus, and / or device.
[0072] The present disclosure further relates to a control arrangement configured to operate a towing unit of a vehicle combination. The control arrangement may be configured to perform any one of the steps of the above described method for operating a towing unit of a vehicle combination.
[0073] More specifically, in accordance with the present disclosure, a control arrangement configured to operate a towing unit of a vehicle combination is provided. The control arrangement is configured to monitor experienced driving resistance of the towing unit during one or more preselected driving situations. The control arrangement is further configured to, based on the experienced driving resistance of the towing unit during the one or more preselected driving situations, analyze possible residuals of a force-based reference model for the towing unit to thereby determine whether the vehicle combination comprises a non-integrated torque producer. Moreover, the control arrangement is configured to, based on the experienced driving resistance of the towing unit duringthe one or more preselected driving situations, analyze possible residuals of a force-based reference model for the towing unit to thereby determine whether the vehicle combination comprises a non-integrated torque producer.The control arrangement may comprise one or more control units. In case the control arrangement comprises a plurality of control units, each control unit may be configured to control a certain step / function or a certain step / function may be divided between more than one control units. The control arrangement may be a control arrangement of a vehicle unit configured to, when comprised in a vehicle combination, act as a towing unit for said vehicle combination. For example, the control arrangement may be comprised in a tractor vehicle unit.
[0074] In those cases where the herein described control arrangement is configured to adjust at least one control strategy for the towing unit (when it is determined that the vehicle comprises a nonintegrated torque producer), the control arrangement may alternatively be described as a control arrangement configured to control a towing unit of a vehicle combination. In such cases where the control arrangement is not configured to adjust at least one control strategy for the towing unit, the control arrangement may alternatively be described as a control arrangement configured to estimate future energy consumption of a towing unit of a vehicle combination, such as for the purpose of estimating distance to empty (i.e. available driving range) for the towing unit and / or route planning.
[0075] The control arrangement may further be configured to map residuals of the force-based reference model for the towing unit in dependence of different driving situations. Moreover, the control arrangement may be configured to analyze the mapped residuals to determine a behavior of the non-integrated torque producer. The control arrangement may also be configured to, based on the determined behavior of the non-integrated torque producer and / or the mapped residuals of the force-based reference model for the towing unit, determine one or more adjusted force-based models for the towing unit, each of the one more adjusted forcebased models being dependent on the driving situation.
[0076] The control arrangement may be configured to communicate with one or more systems of the vehicle unit in which it is comprised, and / or to communicate with one or more systems being at least partly remote from said vehicle unit. For example, the control arrangement may be configured to communicate with a user interface, a route planning system comprised in the vehicle unit, a server-based route planning system, a fleet management system, and / or a server-based system configured to store and / or process historical data from one or more vehicle units. It should here be noted that a server-based system may for example be a cloudbased system.Figure 1 illustrates a side view of an example of a vehicle combination 1. The vehicle combination 1 is here illustrated as a semi-trailer truck, and thus constitutes an example of a vehicle constituting a vehicle combination comprising two vehicle units. The exemplified vehicle combination 1 comprises a towing unit 2 in the form of a tractor truck, and a trailing unit 3 in the form of a semi-trailer. The towing unit 2 comprises drive wheels 4 configured to be driven by a powertrain of the towing unit 2. The drive wheels 4 are equally distributed on both sides of the towing unit, and thus only one of the drive wheels 4 is visible in the figure. The towing unit 2 further comprises front wheels 5, which may typically be non-driven wheels but could alternatively by drive wheels. The trailing unit 3 may be a conventional, non-motorized, trailing unit or it may be a so called e-trailer. In case the trailing unit 3 is an e-trailer, it comprises its own powertrain configured to provide motive power to at least one set of wheels 6, which thus also constitutes drive wheels. Said set of wheels 6 are equally disposed on both sides of the trailing unit 3. In case the trailing unit 3 is a conventional, non-motorized, trailing unit, the wheels 6 are non-driven wheels.
[0077] Figure 2 schematically illustrates an example of a vehicle combination 1 comprising a towing unit 2 and a trailing unit 3. The illustrated vehicle combination 1 may for example correspond to the vehicle combination shown Figure 1 , but is not limited thereto.
[0078] The towing unit 2 of the vehicle combination 1 comprises a first powertrain 20. The first powertrain 20 comprises a first power unit 22, and optionally a second power unit 23. The first power unit 22 may for example be a combustion engine, or an electric motor. The optional second power unit 23 may for example be an electric motor. The towing unit 2 may further comprise an energy storage device 21 configured to power the power unit(s) in case of said power unit(s) constituting electrical motor(s). The first power unit 22 and the optional second power unit 23 are configured to provide motive torque, via a first driveline 24, to a drive wheels 4 of the towing unit 2, and thereby provide motive force to the towing unit 2. The first power unit 22 and / or the optional second power unit 23 may further be configured to provide braking torque to the drive wheels 4 for the purpose of auxiliary braking of the towing unit. The first power unit 22, the optional second power unit 23, the driveline 24 and the drive wheels 4 are all constituent parts of the first powertrain 20. The first driveline 24 comprises a first transmission arrangement 26 connected to, optionally via a first differential 27, a first drive shaft 28. The first drive shaft 28 is in turn connected to the drive wheels 4 of the towing unit 2.The towing unit 2 further comprises a control arrangement 100. The control arrangement 100 may be configured to operate the towing unit 2 in accordance with the herein described method for operating a towing unit of a vehicle combination. The control arrangement 100 may for example be configured to control the powertrain 20 of the towing unit 2, and / or estimate future energy consumption of the towing unit 2.
[0079] The trailing unit 3 of the exemplified vehicle combination 1 comprises its own drive unit, in the form of a second powertrain 30. The second powertrain 30 comprises a third power unit 32 configured to provide force to a plurality of drive wheels 6 of the trailing unit 3 via a second driveline 34. The third power unit 32 may be an electric motor and may be powered by a second energy storage device 31 , said second energy storage device 31 being in the form of a traction battery of the trailing unit. The second driveline 34 may, as shown in the figure, comprise a second transmission arrangement 36 connected to, optionally via a second differential 37, a second drive shaft 38. The second drive shaft 38 is in turn connected to the drive wheels 6 of the trailing unit 3. The second powertrain 30 may for example be an electric axle, also known as an e-axle, but is not limited thereto. The trailing unit 3 may further comprise a controller 300 configured to control the second powertrain 30.
[0080] The second powertrain 30 with its controller 300 may be configured to operate in accordance with control strategies, which may be unknown to the towing unit 2 and its control arrangement 100. In other words, the second powertrain 30 may constitute a non-integrated torque producer of the vehicle combination 1.
[0081] Figure 3 represents a flowchart schematically illustrating one exemplifying embodiment of the herein described method for operating a towing unit of a vehicle combination. More specifically, the exemplifying embodiment constitutes a method for controlling a towing unit of a vehicle combination. Optional steps of the exemplifying embodiment are in the figure illustrated using dashed lines.
[0082] The method comprises a step S101 of monitoring experience driving resistance of the towing unit during one or more preselected driving situations.
[0083] The method further comprises a step S102 of, based on the experienced driving resistance of the towing unit duringthe one or more preselected driving situations, identifying possible residuals of a force-based reference model for driving resistance of the towing unit.The method may optionally further comprise a step S103 of mapping the residuals, identified in step S103, of the force-based reference model for the towing unit in dependence of different driving situations.
[0084] The method further comprises a step S104 of analyzing the residuals, identified in step S103, of the force-based reference model for the towing unit for the purpose of performing a step S105 of determining whether the vehicle combination comprises a non-integrated torque producer.
[0085] In case it is determined in step S105 that the vehicle combination comprises a non-integrated torque producer, the method proceeds to subsequent steps. Otherwise, the method may be reverted to start, as shown in the figure, or alternatively ended.
[0086] In case it is determined in step S105 that the vehicle combination comprises a non-integrated torque producer, the method may comprise a step S106 of analyzing the mapped residuals (obtained from optional step S103) to determine a behavior of the non-integrated torque producer.
[0087] Moreover, the method may comprise a step S107 of, based on the determined behavior of the non-integrated torque producer and / or the mapped residuals of the force-based reference model for the towing unit, determining one or more force-based models for the towing unit, each of the one or more adjusted force-based models being dependent on driving situation.
[0088] The method further comprises a step S108 of, when it is determined in step S105 that the vehicle combination comprises a non-integrated torque producer, adjusting at least one control strategy for the towing unit. In case the method comprises step S107, the step of adjusting the at least one control strategy for the towing unit may suitably be performed based on the one or more adjusted force-based models for the towing unit.
[0089] The method may further comprise a step S109 of, when it is determined in step S105 that the vehicle combination comprises a non-integrated torque producer, re-estimating an expected future energy consumption of the towing unit. In case the method comprises step S107, the step of re-estimating an expected future energy consumption of the towing unit may suitably be performed based on the one or more adjusted force-based models for the towing unit. The re-estimated future energy consumption of the towing unit may for example be used for determining an available driving range, i.e. distance to empty, and / or route planning.
[0090] After step S108, and the optional step S109, the method may be ended, as shown in the figure, or be reverted to start.
[0091] Figure 4 schematically illustrates an exemplifying embodiment of a device 500. The control arrangement 100 described above may for example comprise the device 500, consist of the device 500, or be comprised in the device 500.
[0092] The device 500 comprises a non-volatile memory 520, a data processing unit 510 and a read / write memory 550. The non-volatile memory 520 has a first memory element 530 in which a computer program, e.g. an operating system, is stored for controlling the function of the device 500. The device 500 further comprises a bus controller, a serial communication port, I / O means, an A / D converter, a time and date input and transfer unit, an event counter and an interruption controller (not depicted). The non-volatile memory 520 has also a second memory element 540.
[0093] There is provided a computer program P that comprises instructions for operating a towing unit of a vehicle combination. The computer program comprises instructions for monitoring experienced driving resistance of the towing unit during one or more preselected driving situations. The computer program further comprises instructions for, based on the experienced driving resistance of the towing unit during the one or more preselected driving situations, analyzing possible residuals of a force-based reference model for the towing unit to thereby determine whether the vehicle combination comprises a non-integrated torque producer. The computer program also comprises instructions for, when it is determined that the vehicle combination comprises a non-integrated torque producer, adjusting at least one control strategy for the towing unit and / or re-estimating an expected future energy consumption of the towing unit.
[0094] 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 510 may 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.
[0095] 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 bus 512. The separate memory 560 is intended to communicate with the data processing unit 510 via a data bus 511. The read / write memory 550 is adapted to communicate with the data processing unit 510 via a data bus 514. The communication between the constituent components may be implemented by a communication link. A communication link may be a physical connection such as an optoelectronic communication line, or a non-physical connection such as a wireless connection, e.g. a radio link or microwave link.
[0096] When data are received on the data port 599, they may be stored temporarily in the second memory element 540. When input data received have been temporarily stored, the data processing unit 510 is prepared to effect code execution as described above.
[0097] Parts of the methods herein described may be effected by the device 500 by means of the data processing unit 510 which runs the program stored in the memory 560 or the read / write memory 550. When the device 500 runs the program, methods herein described are executed.
Claims
CLAIMS1. A method, performed by a control arrangement (100), for operating a towing unit (2) of a vehicle combination (1),the method comprising the following steps:monitoring (S101) experienced driving resistance of the towing unit (2) during one or more preselected driving situations,based on the experienced driving resistance of the towing unit (2) during the one or more preselected driving situations, analyzing (S104) possible residuals of a force-based reference model for the towing unit (2) to thereby determine (S105) whether the vehicle combination (1) comprises a non-integrated torque producer, andwhen it is determined that the vehicle combination (1) comprises a non-integrated torque producer, adjusting (S108) at least one control strategy for the towing unit (2) and / or re-estimating (S109) an expected future energy consumption of the towing unit (2).
2. The method according to claim 1 , wherein the towing unit (2) comprises one or more power units (22, 23), andwherein the step of monitoring experienced driving resistance of the towing unit (2) during one or more preselected driving situations comprises monitoring torque output of the one or more power units (22, 23) of the towing unit (2) during the one or more preselected driving situations.
3. The method according to any one of claims 1 and 2, wherein the step of analyzing possible residuals of the force-based reference model for the towing unit (2) comprises determining whether the possible residuals at least partly pertain to possible error(s) in estimation of mass and / or rolling resistance.
4. The method according to any one of the preceding claims, further comprising the steps of:mapping (S103) residuals of the force-based reference model for the towing unit (2) in dependence of different driving situations, andanalyzing the mapped residuals to determine (S106) a behavior of the nonintegrated torque producer.
5. The method according to claim 4, further comprising a step of:based on the determined behavior of the non-integrated torque producer and / or the mapped residuals of the force-based reference model for the towing unit (2), determining (S107) one or more adjusted force-based models for the towing unit (2), each of the one or more adjusted force-based models being dependent on driving situation.
6. The method according to claim 5, wherein the step of adjusting (S108) at least one control strategy for the towing unit (2) is performed based on the determined one or more adjusted force-based models for the towing unit (2).
7. The method according to any one of claims 5 or 6, wherein the step of re-estimating (S109) an expected future energy consumption of the towing unit (2) is performed based on the determined one or more adjusted force-based models for the towing unit (2).
8. The method according to any one of the preceding claims, whereinthe step of re-estimating (S109) an expected future energy consumption of the towing unit (2) comprises estimating future energy consumption of the towing unit (2) for at least two candidate routes of the vehicle combination (1), andthe method further comprises:selecting a route from the at least two candidate routes taking into account the estimated future energy consumption of the towing unit (2) for the at least two candidate routes, orcommunicating the estimated future energy consumption of the towing unit (2) for the at least two candidate routes to a route planning system associated with the towing unit (2), and / or, through usage of a user interface, to a driver of the towing unit (2).
9. The method according to any one of the preceding claims, wherein the step of adjusting (S108) at least one control strategy for the towing unit (2) comprises adjusting a gear selection strategy for the towing unit (2).
10. The method according to any one of the preceding claims, wherein the step of adjusting (S108) at least one control strategy for the towing unit (2) comprises adjusting a control strategy for braking of the towing unit (2) and / or the vehicle combination (1).
11. The method according to any one of the preceding claims, wherein the step of adjusting (S108) at least one control strategy for the towing unit (2) comprises adjusting a cruise control strategy for the towing unit (2).
12. The method according to claim 11 , wherein the step of adjusting (S108) at least one control strategy for the towing unit (2) comprises adjusting a predictive cruise control strategy for the towing unit (2).
13. A control arrangement (100) configured to operate a towing unit (2) of a vehicle combination (1),the control arrangement (100) being configured to:monitor experienced driving resistance of the towing unit (2) during one or more preselected driving situations,based on the experienced driving resistance of the towing unit (2) during the one or more preselected driving situations, analyze possible residuals of a force-based reference model for the towing unit (2) to thereby determine whether the vehicle combination (1) comprises a non-integrated torque producer, andwhen it is determined that the vehicle combination (1) comprises a non-integrated torque producer, adjust at least one control strategy for the towing unit (2) and / or re- estimate an expected future energy consumption of the towing unit (2).
14. The control arrangement (100) according to claim 13, further configured to:map residuals of the force-based reference model for the towing unit (2) in dependence of different driving situations, andanalyze the mapped residuals to determine a behavior of the non-integrated torque producer.
15. The control arrangement (100) according to claim 14, further configured to:based on the determined behavior of the non-integrated torque producer and / or the mapped residuals of the force-based reference model for the towing unit (2), determine one or more adjusted force-based models for the towing unit (2), each of the one more adjusted force-based models being dependent on driving situation.
16. A computer program (P) comprising instructions which, when executed by a control arrangement (100), cause the control arrangement (100) to perform the method according to any one of claims 1 to 12.
17. A computer-readable medium comprising instructions which, when executed by a control arrangement (100), cause the control arrangement (100) to perform the method according to any one of claims 1 to 12.
18. Avehicle unit configured to, when comprised in a vehicle combination (1), act as a towing unit (2) for said vehicle combination (1 ), the vehicle unit comprising a control arrangement (100) according to anyone of claims 13 to 15.