EP4638921A1

EP4638921A1 - Strategy for fan activation during engine brake

Info

Publication number: EP4638921A1
Application number: EP22843184.7A
Authority: EP
Inventors: Tiago CZELUSNIAK; Mauricio WODIANI; Edmar SILVA
Original assignee: Volvo Truck Corp
Current assignee: Volvo Truck Corp
Priority date: 2022-12-20
Filing date: 2022-12-20
Publication date: 2025-10-29
Also published as: WO2024132109A1

Abstract

A computer-implemented method, comprising: detecting (S102), by a processor device of a computer system, that an engine brake torque demand of a vehicle exceeds a demand threshold, detecting (S104), by the processor device, that the speed of the vehicle is above a speed threshold; when the demand threshold and speed threshold are fulfilled, activating (S 106), by the processor device, an engine fan coupled to the engine to add load to the engine; determining (S 108), by the processor device, a total mass of the vehicle; selecting (S 1 10), by the processor device, one of at least three selectable functionalities, wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled.

Description

STRATEGY FOR FAN ACTIVATION DURING ENGINE BRAKE

TECHNICAL FIELD

[0001] The disclosure relates generally to engine braking in vehicles. In particular aspects, the disclosure relates to strategies for fan activation during engine brake. The disclosure can be applied in heavy-duty vehicles, such as trucks, buses, and construction equipment. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle.

BACKGROUND

[0002] Vehicles often have software for different engine brake strategies. To improve the engine brake performance activation of an engine fan has been employed in earlier systems. However, there is still room for improvements with regards to strategies for fan demand and activation for engine brakes.

SUMMARY

[0003] According to a first aspect of the disclosure, there is provided a computer system comprising a processor device configured to: detect that an engine brake torque demand of a vehicle exceeds a demand threshold, detect that the speed of the vehicle is above a speed threshold; when the demand threshold and the speed threshold are fulfilled, activate an engine fan coupled to the engine to add load to the engine; determine a total mass of the vehicle; wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled.

[0004] The first aspect of the disclosure may seek to provide a refined strategy for engine brake fan activation. A technical benefit may include more efficient use of the engine fan to improve engine braking power.

[0005] According to a second aspect of the disclosure, there is provided a computer- implemented method, comprising: detecting, by a processor device of a computer system, that an engine brake torque demand of a vehicle exceeds a demand threshold, detecting, by the processor device, that the speed of the vehicle is above a speed threshold; when the demand threshold and the speed threshold are fulfilled, activating, by the processor device, an engine fan coupled to the engine to add load to the engine; determining, by the processor device, a total mass of the vehicle; selecting, by the processor device, one of at least three selectable functionalities, wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled.

[0006] The second aspect of the disclosure may seek to provide a refined strategy for engine brake fan activation. A technical benefit may include more efficient use of the engine fan to improve engine braking power.

[0007] In some examples, the method may comprise receiving, by the processor device, a message from a stalk selector indicating which of the at least three functionalities to select. A technical benefit may include that a driver may activate and deactivate the engine fan manually when conditions for such activation are enabled.

[0008] In some examples, the stalk selector may be manually operable by a driver of the vehicle. Thus, the driver is provided with manual control of the functionality selection.

[0009] In some examples, the demand threshold may be 80% of maximum engine brake power, and the predetermined duration may be 2 seconds. The threshold and the duration were found particularity advantageous during testing of the engine brake using the engine fan.

[0010] In some examples, the speed threshold may be 20 km/h.

[0011] In some examples, the method may comprise, in the first selectable functionality, setting, by the processor device, the fan speed setpoint at a value determined using a model configured to provide an output fan speed setpoint using the vehicle mass as input. A technical benefit may be that a specifically tailored model may provide for and efficient precalibrated fan speed setpoint based on the vehicle mass which may change with e.g., the weight of a present load.

[0012] In some examples, the method may comprise detecting, by the processor device, a present GPS location of the vehicle, and adjusting, by the processor device, the fan speed setpoint based on the present GPS location and the route ahead of the GPS location. A technical benefit may include that using the GPS location an upcoming road inclination or other road condition may be anticipated so that a suitable fan speed setpoint can be determined prior to reaching a particular position. Thus, the engine fan speed may be adapted to the route ahead.

[0013] In some examples, detecting, by the processor device, a vehicle acceleration during engine brake, and adjusting, by the processor device, the fan speed setpoint based on the vehicle acceleration. A technical benefit may include that the fan speed may be adapted to control the acceleration.

[0014] In some examples, the method may comprise applying, by the processor device, a smoothing electric signal filter for smoothing out fan electrical machine activation. A technical benefit may include that the fan may be activated with slower response and therefore reduced noise and vibration.

[0015] In some examples, the fixed setpoint may be about 2100 rpm.

[0016] In some examples, the method may comprise detecting, by the processor device, that the engine brake torque demand is below a threshold value for a second predetermined time duration, and, in response, disabling, by the processor device, fan demand at engine brake. A technical benefit may include that the fan is automatically deactivated when it is not needed for engine brake, thereby not causing unnecessary load on the engine.

[0017] In some examples, the method may comprise detecting, by the processor device, that an acceleration pedal of the vehicle is actuated, and, in response, disabling, by the processor device, fan demand at engine brake. A technical benefit may include that the fan is automatically deactivated when it is not needed for engine brake, thereby not causing unnecessary load on the engine.

[0018] In some examples, the method may comprise detecting, by the processor device, that the vehicle engine includes an automatic gearbox, and determining, by the processor deice, a present road inclination, wherein, in the first selectable functionality, the fan speed setpoint is further based on a present road inclination. A technical benefit may include more efficient use of the engine fan for engine brake when an automatic gear box is employed by including the road inclination in the strategy for setting the fan speed.

[0019] In some examples, the method may include detecting, by the processor device, that the vehicle engine includes an automatic gearbox, detecting, by the processor device, that the automatic gearbox is in a braking mode and selecting, by the processor device, a fourth selectable fan speed setpoint that is adapted for the automatic gearbox. Thus, a separate fixed fan speed setpoint may be adapted for an automatic gear box, thereby tailored and more efficient use of the engine fan for engine brake when an automatic gear box is employed may be obtained. The fourth selectable fan speed setpoint is lower than the fixed speed setpoint for a manual gear box, e.g., lower than the fixed setpoint of about 2100 rpm. This is advantageous since in automatic gear boxes rapid downshift can lead to higher cabin noise. To reduce the cabin noise, a lower fixed speed setpoint may be used.

[0020] In some examples, the method may comprise: receiving, by the processor device, a message from a stalk selector indicating which of the at least three functionalities to select, wherein the stalk selector is manually operable by a driver of the vehicle, the demand threshold is 80% of maximum engine brake, and the predetermined duration is 2 seconds, the speed threshold is 20 km/h, and the fixed setpoint is about 2100 rpm, the method further comprising: detecting, by the processor device, a present GPS location of the vehicle, adjusting, by the processor device, the fan speed setpoint based on the present GPS location and the route ahead of the GPS location, detecting, by the processor device, a vehicle acceleration during engine brake, and adjusting, by the processor device, the fan speed setpoint based on the vehicle acceleration, detecting, by the processor device, at least one of that the engine brake torque demand is below a threshold value for a second predetermined time duration and that an acceleration pedal of the vehicle is actuated, and, in response, disabling, by the processor device, fan demand at engine brake.

[0021] There is further provided a vehicle comprising the processor device to perform the method of the second aspect.

[0022] There is further provided a computer program product comprising program code for performing, when executed by the processor device, the method of the second aspect. [0023] There is further provided a control system comprising one or more control units configured to perform the method of the second aspect.

[0024] There is further provided a non-transitory computer-readable storage medium comprising instructions, which when executed by the processor device, cause the processor device to perform the method of the second aspect. [0025] The above aspects, accompanying claims, and/or examples disclosed herein above and later below may be suitably combined with each other as would be apparent to anyone of ordinary skill in the art.

[0026] Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be readily apparent therefrom to those skilled in the art or recognized by practicing the disclosure as described herein. There are also disclosed herein control units, computer readable media, and computer program products associated with the above discussed technical benefits.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is an example vehicle according to one example.

[0028] FIG. 2 is an exemplary system diagram of a system according to one example.

[0029] FIG. 3 is a flow chart of an exemplary method to control an engine fan according to one example.

[0030] FIG. 4 is a flow chart of an exemplary method to control an engine fan according to one example.

[0031] FIG. 5 is another view of FIG. 2, according to another example.

[0032] FIG. 6 is a flow chart of an exemplary method to control an engine fan according to one example.

[0033] FIG. 7 is a schematic diagram of an exemplary computer system for implementing examples disclosed herein, according to one example.

DETAILED DESCRIPTION

[0034] Aspects set forth below represent the necessary information to enable those skilled in the art to practice the disclosure.

[0035] FIG. 1 illustrates a vehicle in the form of a truck 1 comprising a combustion engine 2 arranged for providing propulsion for the truck 1. The truck 1 further comprises an engine fan 4 that is generally arranged to cool the engine 2. Herein, the engine fan 4 is further used to add engine braking torque.

[0036] The vehicle 1 further comprises a processor device 102 that controls the engine fan as will be laid out in more detail below. [0037] Although the vehicle in FIG. 1 is depicted as a heavy-duty truck, embodiments of the present disclosure may as well be implemented in other types of vehicles, such as in buses, light-weight trucks, passenger cars, construction equipment, industrial applications, and marine applications including e.g. vessels or ships.

[0038] An engine fan of a vehicle can be used for adding engine braking torque to the braking system of the vehicle. The addition may typically be about 5-7% of added braking power. This typically requires a specific control strategy for the fan to activate it at the right time under given circumstances. The inventors have realized a new strategy that can improve the engine brake performance.

[0039] FIG. 2 is an exemplary system diagram of a system 100 according to one example. The system 100 comprises a processor device 102 configured to detect that an engine brake torque demand of a vehicle exceeds a demand threshold. For this, the processor device may receive a message TD from a braking management controller 104 indicating the present engine brake torque demand. The processor device 102 evaluates the engine brake torque demand in view of the demand threshold to determine whether or not it exceeds the demand threshold. The braking management controller 104 may be a vehicle ECU.

[0040] The engine brake torque demand may be the engine brake percentage demand requested based on a brake torque curve sent by an engine ECU as a function of the engine speed.

[0041] Further, the processor device 102 receives speed data in message SD from a speedometer 106 or e.g., a GPS system or another device capable of measuring present speed of the vehicle. The processor device 102 is configured to detect that the speed of the vehicle is above a speed threshold.

[0042] When each of the demand threshold and the speed threshold are fulfilled, the processor device 102 activates an engine fan 108 coupled to the engine to add load to the engine 110. For this, the processor device 102 sends a control message CM to the engine fan 108. The coupling 112 is a mechanical coupling such as a clutch 112 that enables for the engine fan to engage or disengage with the engine 110. When the fan is engaged with the engine 110, the engine powers the fan 108 and thereby is adding load to the engine, thus, the fan is activated. The fan 108 is normally used for cooling the engine 110, and is typically activated for cooling when the engine speed exceeds some threshold such as at about 2000 rpm. [0043] The processor device 102 determines a total mass of the vehicle. The processor device may retrieve weight data from a non-transitory memory device 114. Furthermore, weight data concerning cargo on the vehicle may be retrieved from e.g., user input also stored on the memory device 114. The processor device 102 may add the vehicle mass to the cargo mass to obtain the total mass of the vehicle.

[0044] The processor device 102 may retrieve a selection message SM from a selector 116 indicating one of several selectable functionalities of the engine fan 108.

[0045] The selector 116 may be a stalk selector indicating which of the at least three functionalities to select. The stalk selector 116 is manually operable by a driver of the vehicle. That is, the driver may push the stalk handle 117 between different positions for selecting the engine brake functionality.

[0046] The message SM is thus related to the engine brake stalk located at the vehicle steering wheel 118. This is the main interface with the driver for engine brake demand. The signal related to the stalk position is processed by a vehicle ECU and is available in the vehicle CAN network.

[0047] In a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass.

[0048] In a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint.

[0049] Experimentally, the strategy discloses herein has shown to add about 10%-12% braking torque to the engine brake, which is about twice that of previous strategies.

[0050] To reduce noise and vibrations, the processor device, may apply a smoothing electric signal filter 122 for smoothing out fan electrical machine activation. Such a filter may be a low-pass filter.

[0051] In a third selectable functionality, the fan demand at engine brake is disabled.

[0052] FIG. 3 is a flow chart of an exemplary method to control the engine fan.

[0053] In step SI 02, detecting, by a processor device 102 of a computer system 100, that an engine brake torque demand of a vehicle exceeds a demand threshold. In examples herein, the demand threshold may be 80% of maximum engine brake.

[0054] In step SI 04, detecting, by the processor device 102, that the speed of the vehicle is above a speed threshold. In examples, the speed threshold may be 20 km/h. [0055] When the demand threshold, and the speed threshold are simultaneously fulfilled, activating, in step SI 06, by the processor device 102, an engine fan coupled to the engine to add load to the engine.

[0056] In step SI 08, determining, by the processor device 102, a total mass of the vehicle. The mass may be measured in kilograms.

[0057] In step SI 10, selecting, by the processor device 102, one of at least three SI, S2, S3, selectable functionalities. The selecting may further include step SI 10a of receiving, by the processor device 102, a message from a stalk selector indicating which of the at least three functionalities to select. In examples, the stalk selector is manually operable by a driver of the vehicle. For example, the stalk selector may be arranged in the cab of the vehicle such as behind the steering wheel where it can be accessed by the driver.

[0058] In a first selectable functionality, SI, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass. Generally, relatively heavier vehicles will demand higher fan speed setpoints. For instance, unloaded vehicles will demand low fan speed, or even 0 rpm, whereas the fan demand setpoint for a fully loaded vehicle may be up to 2300rpm, or even 2500 rpm. In examples, the predetermined duration may be about 2 seconds.

[0059] With regards to setting the fan speed setpoint, the processor device 102 may have access to a model either locally or from a memory 114, that takes the total vehicle mass as input and provides an output fan speed setpoint based on the total vehicle mass. Such a model 120 may be provided as a look-up table and may be based on a theoretical model or an empirical model.

[0060] In a second selectable functionality, S2 the fan speed setpoint is a predetermined fixed speed setpoint. In one example, the fixed setpoint is about 2100 rpm. In the second selectable functionality, the fan is immediately activated without delay, that is, the predetermined duration may be 0 seconds.

[0061] In a third selectable functionality, S3, the fan demand at engine brake is disabled, for example decoupled from the engine.

[0062] In the first selectable functionality, that is, if the driver has selected the first functionality on the stalk selector 116, and the processor device 102 detects that the vehicle engine includes an automatic gearbox, other settings for the fan may be available. For example, the processor device 102 may determine, in step SI 12 a present road inclination, so that the fan speed setpoint may be further based on the present road inclination. In this case, the fan speed setpoint is based both on the vehicle mass and the road inclination in step SI 14. The fan speed setpoint may be determined from a model, e.g. a look-up table, taking mass and road inclination as input and providing fan speed setpoint as output.

[0063] In one example, such a look-up table has one selection column including one of vehicle mass and inclination and one selection row including the other one of vehicle mass and inclination. A fan speed setpoint is available in the look-up table for each combination of vehicle mass and the road inclination.

[0064] Generally, there is a flag, in software, that indicates if the transmission is automatic or manual. If a manual gearbox is used, then the processor device recognizes this and switches the fan at engine brake demand to a curve depending on the vehicle weight only. In case of an automatic gearbox, the processor device switches the fan at engine brake demand to a curve depending on the vehicle weight and road inclination. Typically, a road inclination sensor is only available if an automatic gearbox is used.

[0065] Furthermore, in the second selectable functionality, if the vehicle engine includes an automatic gearbox that is in braking mode, a fourth selectable fan speed setpoint may be selected in step SI 16 that is adapted for the automatic gearbox. The fourth selectable fan speed setpoint is a predetermined fixed speed setpoint that is different from that for a manual gearbox.

[0066] In some examples, the processor device may detect a present GPS location of the vehicle. The GPS coordinate may be received from a navigation system 124 of the vehicle. Based on this GPS location and the route ahead of the GPS location, the processor device may adjust the fan speed setpoint. For example, the processor device 102 may anticipate an upcoming road inclination and set the fan setpoint speed to a speed based on the road inclination. If an upcoming inclination that is closer than some threshold distance the fan speed setpoint may be determined to need adjustment. The adjustment may for example be made in steps of 50 rpm per some percentage of increase or decrease in inclination, measured for instance in percentage of inclination change or as an absolute measure if inclination angle change.

[0067] The inclination may be measured as the angle of the road surface to the horizontal, and may be provided as an angle, or optionally as a slope gradient, Y:X where Y is the altitude rise in meters and X the horizontal run measured in meters, or slope percentage given as rise in e.g., meter divided by the horizontal run measured in meters.

[0068] In some examples, detecting, by the processor device, a vehicle acceleration during engine brake. The acceleration may be calculated from the speed data received from the speedometer 106. The processor device 102 may adjust the fan speed setpoint based on the vehicle acceleration. In one example, the fan speed setpoint is adjusted to provide sufficient engine brake power to maintain the acceleration at or near a predetermined value when driving in a downhill slope. The predetermined value may for example be at or near zero acceleration to keep the vehicle speed stable when travelling downhill. A feedback loop system may be used for feeding back the present acceleration to the processor device, which adapts the fan speed set point to steer the acceleration towards the predetermined value. For example, the feedback loop may be realized by a PI controller receiving as feedback the vehicle acceleration and then adapting the fan speed setpoint based on this acceleration error, for instance in steps of 50 rpm.

[0069] Turning to the flow-chart in FIG. 4. Once the engine fan is activated in any one of the first functionality SI or the second functionality S2, the processor device 102 may disable the engine fan depending on different conditions.

[0070] For example, the processor device may detect in step S202, that the engine brake torque demand is below a threshold value for a second predetermined time duration, and, in response, disabling in step S206, the fan demand at engine brake. Here, the threshold for the engine brake torque demand may be 80% of maximum capacity and the predetermined time duration may be 5 seconds, for disabling the fan demand at engine brake.

[0071] In another example, the processor device detects in step S204, that an acceleration pedal of the vehicle is actuated, and, in response, disabling, in step S206, fan demand at engine brake.

[0072] An accelerator pedal signal may be processed by the processor device and is the pedal percentage demand.

[0073] In one example, the method comprises: receiving, by the processor device, a message from a stalk selector indicating which of the at least three functionalities to select, wherein the stalk selector is manually operable by a driver of the vehicle, the demand threshold is 80% of maximum engine brake, and the predetermined duration is 2 seconds, the speed threshold is 20 km/h, and the fixed setpoint is about 2100 rpm, the method further comprising: detecting, by the processor device, a present GPS location of the vehicle, adjusting, by the processor device, the fan speed setpoint based on the present GPS location and the route ahead of the GPS location, detecting, by the processor device, a vehicle acceleration during engine brake, and adjusting, by the processor device, the fan speed setpoint based on the vehicle acceleration, detecting, by the processor device, at least one of that the engine brake torque demand is below a threshold value for a second predetermined time duration and that an acceleration pedal of the vehicle is actuated, and, in response, disabling, by the processor device, fan demand at engine brake.

[0074] FIG. 5 is another view of FIG. 2, according to another example. A computer system 100 comprising a processor device 102 configured to: detect that an engine brake torque demand of a vehicle exceeds a demand threshold, detect that the speed of the vehicle is above a speed threshold; when the demand threshold, predetermined duration, and speed threshold are fulfilled, activate an engine fan 108 coupled to the engine 110 to add load to the engine; determine a total mass of the vehicle; wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled.

[0075] FIG. 6 is a flow chart of a method to control an engine fan according to one example. In step SI 02, detecting, by a processor device of a computer system, that an engine brake torque demand of a vehicle exceeds a demand threshold,

[0076] In step SI 04, detecting, by the processor device, that the speed of the vehicle is above a speed threshold.

[0077] When the demand threshold, predetermined duration, and speed threshold are fulfilled, activating, in step SI 06, by the processor device, an engine fan coupled to the engine to add load to the engine.

[0078] In step SI 08, determining, by the processor device, a total mass of the vehicle; [0079] In step SI 10, selecting, by the processor device, one of at least three selectable functionalities.

[0080] In a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass. [0081] In a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint.

[0082] In a third selectable functionality, the fan demand at engine brake is disabled.

[0083] FIG. 7 is a schematic diagram of a computer system 700 for implementing examples disclosed herein. The computer system 700 is adapted to execute instructions from a computer-readable medium to perform these and/or any of the functions or processing described herein. The computer system 700 may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. While only a single device is illustrated, the computer system 700 may include any collection of devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. Accordingly, any reference in the disclosure and/or claims to a computer system, computing system, computer device, computing device, control system, control unit, electronic control unit (ECU), processor device, etc., includes reference to one or more such devices to individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. For example, control system may include a single control unit or a plurality of control units connected or otherwise communicatively coupled to each other, such that any performed function may be distributed between the control units as desired. Further, such devices may communicate with each other or other devices by various system architectures, such as directly or via a Controller Area Network (CAN) bus, etc.

[0084] The computer system 700 may comprise at least one computing device or electronic device capable of including firmware, hardware, and/or executing software instructions to implement the functionality described herein. The computer system 700 may include a processor device 702 (may also be referred to as a control unit), a memory 704, and a system bus 706. The computer system 700 may include at least one computing device having the processor device 702. The system bus 706 provides an interface for system components including, but not limited to, the memory 704 and the processor device 702. The processor device 702 may include any number of hardware components for conducting data or signal processing or for executing computer code stored in memory 704. The processor device 702 (e.g., control unit) may, for example, include a general-purpose processor, an application specific processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a circuit containing processing components, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor device may further include computer executable code that controls operation of the programmable device.

[0085] The system bus 706 may be any of several types of bus structures that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and/or a local bus using any of a variety of bus architectures. The memory 704 may be one or more devices for storing data and/or computer code for completing or facilitating methods described herein. The memory 704 may include database components, object code components, script components, or other types of information structure for supporting the various activities herein. Any distributed or local memory device may be utilized with the systems and methods of this description. The memory 704 may be communicably connected to the processor device 702 (e.g., via a circuit or any other wired, wireless, or network connection) and may include computer code for executing one or more processes described herein. The memory 704 may include non-volatile memory 708 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.), and volatile memory 710 (e.g., randomaccess memory (RAM)), or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a computer or other machine with a processor device 702. A basic input/output system (BIOS) 712 may be stored in the non-volatile memory 708 and can include the basic routines that help to transfer information between elements within the computer system 700.

[0086] The computer system 700 may further include or be coupled to a non-transitory computer-readable storage medium such as the storage device 714, which may comprise, for example, an internal or external hard disk drive (HDD) (e.g., enhanced integrated drive electronics (EIDE) or serial advanced technology attachment (SATA)), HDD (e.g., EIDE or SATA) for storage, flash memory, or the like. The storage device 714 and other drives associated with computer-readable media and computer-usable media may provide nonvolatile storage of data, data structures, computer-executable instructions, and the like. [0087] A number of modules can be implemented as software and/or hard-coded in circuitry to implement the functionality described herein in whole or in part. The modules may be stored in the storage device 714 and/or in the volatile memory 710, which may include an operating system 716 and/or one or more program modules 718. All or a portion of the examples disclosed herein may be implemented as a computer program product 720 stored on a transitory or non-transitory computer-usable or computer-readable storage medium (e.g., single medium or multiple media), such as the storage device 714, which includes complex programming instructions (e.g., complex computer-readable program code) to cause the processor device 702 to carry out the steps described herein. Thus, the computer-readable program code can comprise software instructions for implementing the functionality of the examples described herein when executed by the processor device 702. The processor device 702 may serve as a controller or control system for the computer system 700 that is to implement the functionality described herein.

[0088] The computer system 700 also may include an input device interface 722 (e.g., input device interface and/or output device interface). The input device interface 722 may be configured to receive input and selections to be communicated to the computer system 700 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices may be connected to the processor device 702 through the input device interface 722 coupled to the system bus 706 but can be connected through other interfaces such as a parallel port, an Institute of Electrical and Electronic Engineers (IEEE) 1394 serial port, a Universal Serial Bus (USB) port, an IR interface, and the like. The computer system 700 may include an output device interface 724 configured to forward output, such as to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 700 may also include a communications interface 726 suitable for communicating with a network as appropriate or desired.

[0089] The operational steps described in any of the exemplary aspects herein are described to provide examples and discussion. The steps may be performed by hardware components, may be embodied in machine-executable instructions to cause a processor to perform the steps, or may be performed by a combination of hardware and software. Although a specific order of method steps may be shown or described, the order of the steps may differ. In addition, two or more steps may be performed concurrently or with partial concurrence. [0090] Example 1 : a computer system comprising a processor device configured to: detect that an engine brake torque demand of a vehicle exceeds a demand threshold for longer than a predetermined duration, detect that the speed of the vehicle is above a speed threshold; when the demand threshold, predetermined duration, and speed threshold are fulfilled, activate an engine fan coupled to the engine to add load to the engine; determine a total mass of the vehicle; wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled.

[0091] Example 2: a computer-implemented method, comprising: detecting, by a processor device of a computer system, that an engine brake torque demand of a vehicle exceeds a demand threshold for longer than a predetermined duration, detecting, by the processor device, that the speed of the vehicle is above a speed threshold; when the demand threshold, predetermined duration, and speed threshold are fulfilled, activating, by the processor device, an engine fan coupled to the engine to add load to the engine; determining, by the processor device, a total mass of the vehicle; selecting, by the processor device, one of at least three selectable functionalities, wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled.

[0092] Example 3: the method of example 2, further comprising: receiving, by the processor device, a message from a stalk selector indicating which of the at least three functionalities to select.

[0093] Example 4: the method of example 3, wherein the stalk selector is manually operable by a driver of the vehicle.

[0094] Example 5: the method of any of examples 2-4, wherein the demand threshold is 80% of maximum engine brake, and the predetermined duration is 2 seconds.

[0095] Example 6: the method of any of examples 2-5, wherein the speed threshold is 20 km/h. [0096] Example 7: the method of any of examples 2-6, comprising: in the first selectable functionality, setting, by the processor device, the fan speed setpoint at a value determined using a model configured to provide an output fan speed setpoint using the vehicle mass as input.

[0097] Example 8: The method of any of examples 2-7, comprising: detecting, by the processor device, a present GPS location of the vehicle, and adjusting, by the processor device, the fan speed setpoint based on the present GPS location and the route ahead of the GPS location.

[0098] Example 9: the method of any of examples 2-8, comprising: detecting, by the processor device, a vehicle acceleration during engine brake, and adjusting, by the processor device, the fan speed setpoint based on the vehicle acceleration.

[0099] Example 10: the method of any of examples 2-9, comprising: applying, by the processor device, a smoothing electric signal filter for smoothing out fan electrical machine activation.

[00100] Example 11 : the method of any of examples 2-10, wherein the fixed setpoint is about 2100 rpm.

[00101] Example 12: the method of any of examples 2-11, comprising: detecting, by the processor device, that the engine brake torque demand is below a threshold value for a second predetermined time duration, and, in response, disabling, by the processor device, fan demand at engine brake.

[00102] Example 13: the method of any of examples 2-12, comprising: detecting, by the processor device, that an acceleration pedal of the vehicle is actuated, and, in response, disabling, by the processor device, fan demand at engine brake.

[00103] Example 14: the method of any of examples 2-13, comprising: detecting, by the processor device, that the vehicle engine includes an automatic gearbox, and determining, by the processor deice, a present road inclination, wherein, in the first selectable functionality, the fan speed setpoint is further based on a present road inclination.

[00104] Example 15: the method of any of examples 2-14, comprising: detecting, by the processor device, that the vehicle engine includes an automatic gearbox, detecting, by the processor device, that the automatic gearbox is in a braking mode and selecting, by the processor device, a fourth selectable fan speed setpoint that is adapted for the automatic gearbox. [00105] Example 16: the method of any of examples 2-15, comprising: receiving, by the processor device, a message from a stalk selector indicating which of the at least three functionalities to select, wherein the stalk selector is manually operable by a driver of the vehicle, the demand threshold is 80% of maximum engine brake, and the predetermined duration is 2 seconds, the speed threshold is 20 km/h, and, the fixed setpoint is about 2100 rpm, the method further comprising: detecting, by the processor device, a present GPS location of the vehicle, adjusting, by the processor device, the fan speed setpoint based on the present GPS location and the route ahead of the GPS location, detecting, by the processor device, a vehicle acceleration during engine brake, and adjusting, by the processor device, the fan speed setpoint based on the vehicle acceleration, detecting, by the processor device, at least one of that the engine brake torque demand is below a threshold value for a second predetermined time duration and that an acceleration pedal of the vehicle is actuated, and, in response, disabling, by the processor device, fan demand at engine brake.

[00106] Example 17: a vehicle comprising the processor device to perform the method of any of examples 2-16.

[00107] Example 18: a computer program product comprising program code for performing, when executed by the processor device, the method of any of examples 2-16. [00108] Example 19: a control system comprising one or more control units configured to perform the method of any of examples 2-16.

[00109] Example 20: a non-transitory computer-readable storage medium comprising instructions, which when executed by the processor device, cause the processor device to perform the method of any of examples 2-16.

[00110] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" when used herein specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. [00111] It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

[00112] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[00113] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[00114] It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the inventive concepts being set forth in the following claims.

Claims

What is claimed is:

1. A computer system comprising a processor device configured to: detect that an engine brake torque demand of a vehicle exceeds a demand threshold, detect that the speed of the vehicle is above a speed threshold; when the demand threshold, and speed threshold are fulfilled, activate an engine fan coupled to the engine to add load to the engine; determine a total mass of the vehicle; wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled.

2. A computer-implemented method, comprising: detecting (SI 02), by a processor device of a computer system, that an engine brake torque demand of a vehicle exceeds a demand threshold, detecting (SI 04), by the processor device, that the speed of the vehicle is above a speed threshold; when the demand threshold, and the speed threshold are fulfilled, activating (SI 06), by the processor device, an engine fan coupled to the engine to add load to the engine; determining (SI 08), by the processor device, a total mass of the vehicle; selecting (SI 10), by the processor device, one of at least three selectable functionalities, wherein: in a first selectable functionality, when the engine brake torque demand exceeds the demand threshold for longer than a predetermined duration, a fan speed setpoint is based on the vehicle mass, in a second selectable functionality, the fan speed setpoint is a predetermined fixed power setpoint, and in a third selectable functionality, the fan demand at engine brake is disabled. 3. The method of claim 2, further comprising: receiving, by the processor device, a message from a stalk selector indicating which of the at least three functionalities to select, wherein the stalk selector is manually operable by a driver of the vehicle.

4. The method of any of claims 2-3, wherein the demand threshold is 80% of maximum engine brake, and the predetermined duration is 2 seconds.

5. The method of any of claims 2-4, wherein the speed threshold is 20 km/h.

6. The method of any of claims 2-5, comprising: in the first selectable functionality, setting, by the processor device, the fan speed setpoint at a value determined using a model configured to provide an output fan speed setpoint using the vehicle mass as input.

7. The method of any of claims 2-6, comprising: detecting, by the processor device, a present GPS location of the vehicle, and adjusting, by the processor device, the fan speed setpoint based on the present GPS location and the route ahead of the GPS location.

8. The method of any of claims 2-8, comprising: detecting, by the processor device, a vehicle acceleration during engine brake, and adjusting, by the processor device, the fan speed setpoint based on the vehicle acceleration.

11. The method of any of claims 2-10, wherein the fixed setpoint is about 2100 rpm.

12. The method of any of claims 2-11, comprising: detecting, by the processor device, that the engine brake torque demand is below a threshold value for a second predetermined time duration, and, in response, disabling, by the processor device, fan demand at engine brake. 13. The method of any of claims 2-12, comprising: detecting, by the processor device, that an acceleration pedal of the vehicle is actuated, and, in response, disabling, by the processor device, fan demand at engine brake.

14. The method of any of claims 2-13, comprising: detecting, by the processor device, that the vehicle engine includes an automatic gearbox, and determining, by the processor deice, a present road inclination, wherein, in the first selectable functionality, the fan speed setpoint is further based on a present road inclination.

15. The method of any of claims 2-14, comprising: detecting, by the processor device, that the vehicle engine includes an automatic gearbox, detecting, by the processor device, that the automatic gearbox is in a braking mode and selecting, by the processor device, a fourth selectable fan speed setpoint that is adapted for the automatic gearbox.

16. The method of any of claims 2-15, comprising: receiving, by the processor device, a message from a stalk selector indicating which of the at least three functionalities to select, wherein the stalk selector is manually operable by a driver of the vehicle, the demand threshold is 80% of maximum engine brake, and the predetermined duration is 2 seconds, the speed threshold is 20 km/h, and the fixed setpoint is about 2100 rpm, the method further comprising detecting, by the processor device, a present GPS location of the vehicle, adjusting, by the processor device, the fan speed setpoint based on the present GPS location and the route ahead of the GPS location, detecting, by the processor device, a vehicle acceleration during engine brake, and adjusting, by the processor device, the fan speed setpoint based on the vehicle acceleration, detecting, by the processor device, at least one of that the engine brake torque demand is below a threshold value for a second predetermined time duration and that an acceleration pedal of the vehicle is actuated, and, in response, disabling, by the processor device, fan demand at engine brake.

17. A vehicle comprising the processor device to perform the method of any of claims 2- 16.

18. A computer program product comprising program code for performing, when executed by the processor device, the method of any of claims 2-16.

19. A control system comprising one or more control units configured to perform the method of any of claims 2-16.

20. A non-transitory computer-readable storage medium comprising instructions, which when executed by the processor device, cause the processor device to perform the method of any of claims 2-16.