EP4626742A1

EP4626742A1 - A method for increasing brake performance in a fuel cell electric vehicle

Info

Publication number: EP4626742A1
Application number: EP22822585.0A
Authority: EP
Inventors: Martin WILHELMSSON; Linus NORDHOLM; Tobias SMIDEBRANT; Gabriel Trönnberg; Johan Bjernetun; Jenny BLOMQVIST; Johan Lindberg; Johan Axelsson
Original assignee: Volvo Truck Corp
Current assignee: Volvo Truck Corp
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2025-10-08
Also published as: WO2024114904A1

Abstract

The disclosure relates to a computer system (800) comprising a processor device (1) for increasing brake performance in a fuel cell electric vehicle (3), the fuel cell electric vehicle (3) comprising a fuel cell unit (12), an electric energy storage system (14), and a navigational system (16). The processor device (1) is configured to obtain data on an upcoming downhill road section along a planned route of the fuel cell electric vehicle (3) and select a route to the downhill road section which provides the most efficient regenerative braking performance during descent of the downhill road section. The disclosure also relates to a computer-implemented method (2) for increasing brake performance in the fuel cell electric vehicle (3).

Description

A METHOD FOR INCREASING BRAKE PERFORMANCE IN A FUEL CELL ELECTRIC VEHICLE

TECHNICAL FIELD

[0001] The disclosure relates generally to fuel cell electric vehicles. In particular aspects, the disclosure relates to a method for increasing brake performance in a fuel cell electric vehicle. 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] During downhill descents of a fuel cell vehicle, regenerative braking may charge an electric energy storage system, such as batteries of the vehicle. If a state of energy (SoE) of the electric energy storage system is fully replenished during the descent, the regenerative braking stops working and the vehicle may have to rely on its service brakes, which may pose a safety problem if the vehicle still has some distance to descend, since there is a risk that the service brakes could overheat and lose braking ability.

[0003] A typical fuel cell unit has a minimum power level that can be provided, which can typically be somewhere around 7 kW. It is not possible for the fuel cell unit to provide less power without turning off the fuel cell unit.

[0004] It is also important to note that it is important to minimize the number of times that the fuel cell unit is turned off, i.e. the number of times it is stopped and started, since it contributes to ageing of the fuel cell.

[0005] If the fuel cell vehicle, shortly before a long downhill descent, has spent time in queues, etc, with a low average power consumption, there is a risk that the minimum power generated by the fuel cell exceeds the fuel cell vehicle’s actual need for power, which results in an increase in the state of energy and the electric energy storage system of the vehicle to become charged. It may then be difficult to keep the state of energy low enough to allow for sufficiently powerful regenerative braking during the downhill descent. SUMMARY

[0006] According to a first aspect of the disclosure, there is provided a computer system comprising a processor device for increasing brake performance in a fuel cell electric vehicle. The fuel cell electric vehicle comprises a fuel cell unit, an electric energy storage system, and a navigational system. The processor device is configured to: from the navigation system, obtain data on an upcoming downhill road section along a planned route of the fuel cell electric vehicle, determine a maximum preferred state of energy of the electric energy storage system associated with the downhill road section, predict, for the planned route, a predicted state of energy that the electric energy storage system will have at a start of the downhill road section, if the predicted state of energy exceeds the maximum preferred state of energy associated with the downhill road section, search for at least one alternative route to the downhill road section, and predict for the at least one alternative route an alternative state of energy that the electric energy storage system will have at the start of the downhill road section, and select, from among the at least one alternative route and the planned route, an updated route of the fuel cell electric vehicle providing the most efficient regenerative braking performance.

[0007] The first aspect of the disclosure may seek to achieve a state of energy of the electric energy storage system which is sufficiently low, before a downhill road section, to allow sufficient regenerative braking during descent of the downhill road section. Sufficient regenerative braking should be understood as enough regenerative braking to not risk overheating the service brakes of the fuel cell electric vehicle when there is still some distance to descend before reaching an end of the downhill road section. A technical benefit may include a safer downhill descent of the fuel cell electric vehicle, along with improved lifetime of the fuel cell unit and of the service brakes. In addition, the state of energy of the electric energy storage system may be charged to a significant degree at the end of the downhill road section.

[0008] The data on the upcoming downhill road section may be provided by the navigational system. The data may comprise information on height, inclination and/or length of the downhill road section to enable determining a potential increase in the state of energy of the electric energy storage system when descending the downhill road section. The data may also comprise information on a topography of the downhill road section, such as if the downhill road section comprises one continuous slope or a plurality of slopes. The data may further comprise information on alternative routes along the planned route.

[0009] Determining the maximum preferred state of energy of the electric energy storage system associated with the downhill road section involves determining a level of the state of energy at a beginning of the downhill road section, which level allows regenerative braking during the whole descent of the downhill road section. In other words, the maximum preferred state of energy allows charging of the electric energy storage system (i.e. increase of state of energy) during the whole descent of the downhill road section. The maximum preferred state of energy is determined from characteristics of the downhill road section obtained from the navigational system and from known/stored data about the fuel cell electric vehicle.

[0010] The fuel cell electric vehicle obtains data on upcoming downhill road sections when a destination is set, and a route is planned in the navigational system. When predicting a state of energy at the start of the downhill road section, the processor device uses data from the navigational system about the planned route of the fuel cell electric vehicle up until the start of the downhill road section. This data may include weather and/or ambient temperature data. The processor device also uses data about the vehicle, such as weight, speed, current state of energy, etc.

[0011] If the predicted state of energy exceeds the preferred state of energy at the start of the downhill road section, it means that state of energy of the electric energy storage system should preferably be decreased before reaching the downhill road section in order to improve regenerative braking capacity during the downhill descent. Therefore, the processor device and/or the navigational system identify alternative routes to the downhill road section and predicts for each alternative route an alternative state of energy that the electric energy storage system will have at the start of the downhill road section.

[0012] From the alternative routes and the planned route, an updated route to the downhill road section is selected and set in the navigational system. The selected updated route is the route that provides the most efficient regenerative braking performance during descent of the upcoming downhill road section. [0013] According to a second aspect of the present disclosure, there is provided a computer-implemented method for increasing brake performance in a fuel cell electric vehicle. The fuel cell electric vehicle comprises a fuel cell unit, an electric energy storage system, a navigational system and a computer system comprising a processor device. The method comprising, by the processor device: from the navigation system, obtaining data on an upcoming downhill road section along a planned route of the fuel cell electric vehicle, determining a maximum preferred state of energy of the electric energy storage system associated with the downhill road section, predicting, for the planned route, a state of energy that the electric energy storage system will have at a start of the downhill road section, if the predicted current state of energy exceeds the maximum preferred state of energy associated with the downhill road section, searching for at least one alternative route to the downhill road section, and predicting for the at least one alternative route an alternative state of energy that the electric energy storage system will have at the start of the downhill road section, and selecting, from among the at least one alternative route and the planned route, an updated route of the fuel cell electric vehicle providing the most efficient regenerative braking performance.

[0014] The second aspect of the disclosure solves corresponding problems with corresponding technical effects and benefits as the first aspect of the disclosure.

[0015] In some examples, the most efficient regenerative braking performance is the regenerative braking performance providing, during the downhill road section, the highest increase of the state of energy of the electric energy storage system and, if at least two routes provide equivalent increases of the state of energy of the electric energy storage system, the most efficient regenerative braking performance is delivered by the route of said at least two routes providing the highest state of energy of the electric energy storage system at an end of the downhill road section.

[0016] A technical benefit may include that the regenerative braking providing the most braking power is selected by prioritizing the highest increase of the state of energy. This means that from a number of alternative routes, the route providing the longest duration of regenerative braking during the downhill descent is selected. If equivalent routes exist, the route providing the highest state of energy at the end of the downhill road section is selected. In other words, if two routes allow similar durations of regenerative braking during the downhill descent, the route providing the highest state of energy in the end is selected. A high state of energy is particularly beneficial in case the downhill road section is followed by significant uphill road sections.

[0017] In some examples, the action of predicting the state of energy for the planned route and/or the action of predicting the state of energy for the at least one alternative route comprises estimating if the fuel cell unit will be switched off at least once before the start of the downhill road section, and if the fuel cell is estimated to be switched off, generating an alert for the planned route or for the at least one alternative route, respectively. A technical benefit may include avoiding routes along which the fuel cell unit would be switched of at least once, and perhaps repeatedly, due to low consumption of electric energy of the fuel cell electric vehicle. The generated alert may be provided to a user of the fuel cell electric vehicle or to an autonomous control system of the fuel cell electric vehicle. The user or the autonomous system may thereafter decide on the suitability of any routes for which an alert has been generated. Service life of the fuel cell unit may be extended by avoiding switching the fuel cell unit on and off.

[0018] In some examples, the method further comprises continuously or intermittently collecting and updating traffic information for the current planned route. A technical benefit may include instantly learning when traffic jams occur such that an alternative route may be selected before arriving at the downhill road section.

[0019] In some examples, the data on the upcoming downhill road section comprises the traffic information. A technical benefit may include learning where traffic is slow, i.e. traffic in which the fuel cell unit provides more power than the fuel cell electric vehicle consumes, resulting in an increase of the state of energy of the electric energy storage system before the arriving at the downhill road section. Slow traffic should usually be avoided before a downhill road section. The traffic information allows selection of an alternative route that avoids slow traffic. The updated route may be longer than the previous planned route. However, the expected time of arrival (ETA) at the destination for each alternative route may be included in the data obtained from the navigational system and may affect the selection of the updated route. A significantly delayed time of arrival at the destination is usually not preferred. [0020] In some examples, the data on the upcoming downhill road section comprises the traffic information obtained from other vehicles or through telematics, such as from road sensors or other monitoring devices with which the processor device of the vehicle may be communicatively connected. A technical benefit may include more recent and reliable data generated by recent traffic events which are encountered by other vehicles or, for instance, reported from road sensors.

In some examples, the selected updated route is provided to a user of the fuel cell electric vehicle, or to an autonomous control system of the fuel cell electric vehicle, as a suggested route. A technical benefit may include that the driver or the autonomous control system is enabled to accept or reject the suggested route, allowing the possibility of various other considerations to affect the selection of the updated route.

In some examples, the predicted state of energy is predicted based on data from the navigational system of the fuel cell electric vehicle combined with GPS and/or GNSS data received by the fuel cell electric vehicle. A technical benefit may include a more accurate estimation of the state of energy by the combination of location of the vehicle with road information, i.e. inclination of the road, curvature, etc.

[0021] In some examples, wherein the selection of the updated route is further based on historical data on routes travelled by the fuel cell electric vehicle. The historical data may be continuously collected and stored by the vehicle when travelling, either on board the vehicle or in a centrally located computer server with which the processor device is communicatively connected. A technical benefit may include learning, by the processor device, consumption of energy, traffic patterns, weather conditions, topography, etc. along routes frequently travelled by the fuel cell electric vehicle. Optionally, the historical data may comprise data collected by other similar fuel cell electric vehicles. Predictions based on historical data may be more accurate than other available data.

[0022] According to a third aspect of the present disclosure, there is provided fuel cell electric vehicle comprising the processor device configured to perform the method of any of the embodiments of the second aspect of the disclosure.

[0023] According to a fourth aspect of the present disclosure, there is provided a computer program product comprising program code for performing, when executed by the processor device, the method of any of the embodiments of the second aspect of the disclosure. [0024] According to a fifth aspect of the present disclosure, there is provided a control system comprising one or more processor devices configured to perform the method of any of the embodiments of the second aspect of the disclosure.

[0025] According to a sixth aspect of the present disclosure, there is 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 any of the embodiments of the second aspect of the disclosure.

[0026] 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.

[0027] 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

[0028] With reference to the appended drawings, below follows a more detailed description of aspects of the disclosure cited as examples.

[0029] FIG. 1 is a fuel cell electric vehicle according to one example.

[0030] FIG. 2 is a flowchart of a method according to one example.

[0031] FIG. 3 shows an exemplary driving scenario.

[0032] FIG. 4 shows another exemplary driving scenario.

[0033] FIG. 5 shows another exemplary driving scenario.

[0034] FIG. 6 shows an exemplary driving scenario according to an aspect of the disclosure.

[0035] FIG. 7 is an exemplary control system according to one example.

[0036] FIG. 8 is a schematic diagram of an exemplary computer system for implementing examples disclosed herein, according to one example.

DETAILED DESCRIPTION [0037] Aspects set forth below represent the necessary information to enable those skilled in the art to practice the disclosure.

[0038] An object of the present disclosure is to provide an improved method for increasing regenerative braking performance in fuel cell electric vehicles. The method avoids frequent starts and stops of a fuel cell unit of the fuel cell electric vehicle and prepares an electric energy storage system of the fuel cell electric vehicle to receive regenerative braking power during descents of downhill road sections. Results include extended life of the fuel cell unit, safer downhill driving and/or extended life of service brakes of the vehicle.

[0039] FIG. 1 shows a fuel cell electric vehicle 3 according to a third aspect of the disclosure. The fuel cell electric vehicle 3 may comprise one or more electric motors for propulsion of the vehicle. The fuel cell electric vehicle 3 may comprise a computer system 800 (see FIG. 8) comprising a processor device 1 according to a first aspect of the disclosure. The fuel cell electric vehicle 3 may also comprise a fuel cell unit 12 and an electric energy storage system 14. During operation of the fuel cell electric vehicle 3, the fuel cell unit 12 is usually switched on and generates electric energy, which energy is preferably stored in the electric energy storage system 14. The electric energy storage system may comprise one or more batteries. The fuel cell electric vehicle 3 may further comprise a navigational system 16 for determining a route to a destination. The fuel cell electric vehicle 3 may be a heavy-duty vehicle, such as a truck, a bus, or construction equipment. The disclosure is not restricted to any particular vehicle.

[0040] FIG. 2 is a flowchart illustrating a method 2 according to a second aspect of the disclosure. The method 2 relates to a computer-implemented method 2 for increasing brake performance in the fuel cell electric vehicle 3. As mentioned above, the fuel cell electric vehicle 3 may comprise a fuel cell unit 12, an electric energy storage system 14, a navigational system 16 and a computer system 800 comprising a processor device 1. The method 2 comprises, by the processor device 1:

- SI: from the navigational system 16, obtaining data on an upcoming downhill road section along a planned route of the fuel cell electric vehicle 3,

- S2: determining a maximum preferred state of energy MPref of the electric energy storage system 14 associated with the downhill road section,

- S3: predicting, for the planned route, a state of energy Pred that the electric energy storage system 14 will have at a start of the downhill road section, - S4: if the predicted current state of energy Pred exceeds the maximum preferred state of energy MPref associated with the downhill road section, searching for at least one alternative route to the downhill road section, and predicting for the at least one alternative route an alternative state of energy AltPred that the electric energy storage system 14 will have at the start of the downhill road section, and

- S5: selecting from among the at least one alternative route and the planned route, an updated route of the fuel cell electric vehicle providing the most efficient regenerative braking performance.

[0041] The method 2 seeks to achieve a state of energy of the electric energy storage system 14 which is sufficiently low, before the downhill road section, to allow sufficient regenerative braking power during descent of the downhill road section. Sufficient regenerative braking power should be understood as enough regenerative braking power to not risk overheating the service brakes of the fuel cell electric vehicle 3 when there is still some distance to descend before reaching an end of the downhill road section.

[0042] The data on the upcoming downhill road section may be provided by the navigational system 16. The data may comprise information on height, inclination and/or length of the downhill road section to enable determining a potential increase in the state of energy of the electric energy storage system 14 when descending the downhill road section. The data may also comprise information on a topography of the downhill road section, such as if the downhill road section comprises one continuous slope or a plurality of slopes. The data may further comprise information on alternative routes along the planned route.

[0043] The action S2 of determining the maximum preferred state of energy MPref of the electric energy storage system 14 associated with the downhill road section involves determining a level of the state of energy at a beginning of the downhill road section, which level allows regenerative braking during the whole descent of the downhill road section. In other words, the maximum preferred state of energy MPref allows charging of the electric energy storage system 14 (i.e. increase of state of energy) during the whole descent of the downhill road section. The maximum preferred state of energy MPref is determined from characteristics of the downhill road section obtained from the navigational system and from known/stored data about the fuel cell electric vehicle 3.

[0044] The processor device 1 of the fuel cell electric vehicle 3 obtains data on the upcoming downhill road sections when a destination is set, and a route is planned in the navigational system 16. For the action S3 of predicting a state of energy at the start of the downhill road section, the processor device 1 uses data from the navigational system 16 about the planned route of the fuel cell electric vehicle 3 up until the start of the downhill road section. This data may include weather and/or ambient temperature data along the route. The processor device 1 may also use data on characteristics of the fuel cell electric vehicle 3, such as weight, speed, current state of energy, etc. Characteristics of the fuel cell electric vehicle 3 may be pre-registered and stored on a non-transitory computer-readable storage medium, which may be on board the vehicle and/or which may be communicatively connected to the processor device 1.

[0045] If the predicted state of energy Pred exceeds the maximum preferred state of energy MPref at the start of the downhill road section, it means that state of energy of the electric energy storage system 14 should preferably be decreased before reaching the downhill road section in order to improve regenerative braking capacity during the downhill descent. Therefore, the processor device 1 and/or the navigational system 16 identify alternative routes to the downhill road section and predicts for each alternative route an alternative state of energy AltPred that the electric energy storage system 14 will have at the start of the downhill road section.

[0046] From the alternative routes and the planned route, an updated route to the downhill road section is selected and set in the navigational system 16. The selected updated route is the route that provides the most efficient regenerative braking performance during descent of the upcoming downhill road section.

[0047] The most efficient regenerative braking performance is the regenerative braking performance providing, during the downhill road section, the highest increase of the state of energy of the electric energy storage system 14. If at least two routes provide equivalent increases of the state of energy of the electric energy storage system 14, the most efficient regenerative braking performance is delivered by the route providing the highest state of energy of the electric energy storage system 14 at an end of the downhill road section.

[0048] This means that from a number of alternative routes, the route providing the longest duration of regenerative braking during the downhill descent is selected. If equivalent routes exist, the route providing the highest state of energy at the end of the downhill road section is selected. In other words, if two routes allow similar durations of regenerative braking during the downhill descent, the route providing the highest state of energy at the end of the downhill road section is selected. A high state of energy is particularly beneficial in case the downhill road section is followed by significant uphill road sections.

[0049] The action of predicting the state of energy for the planned route and/or the action of predicting the state of energy for the at least one alternative route may comprise estimating if the fuel cell unit 12 will be switched off at least once before the start of the downhill road section. If the fuel cell is estimated to be switched off, an alert may be generated by the processor device 1 for the planned route and/or for the at least one alternative route, respectively. Routes along which the fuel cell unit would be switched of at least once, and perhaps repeatedly, due to low consumption of electric energy of the fuel cell electric vehicle may thereby be avoided. The generated alert may be provided to a user of the fuel cell electric vehicle 3 or to an autonomous control system of the fuel cell electric vehicle 3. The user or the autonomous system may thereafter decide on the suitability of any routes for which such a switch-off alert has been generated.

[0050] The method may further comprise continuously or intermittently collecting and updating traffic information for the current planned route, e.g. from an off-board and central traffic information server, from other vehicles etc. Thereby, processor device of the computer system 800 instantly learn when traffic jams occur such that an alternative route may be selected before arriving at the downhill road section.

[0051] The data on the upcoming downhill road section may comprise such traffic information. It is thereby possible to predict where traffic is slow, i.e. where the fuel cell unit 12 will likely provide more power than the fuel cell electric vehicle 3 consumes, resulting in an increase of the state of energy of the electric energy storage system 14 before the arriving at the downhill road section. Slow traffic should usually be avoided before a downhill road section. The traffic information allows selection of an alternative route that avoids slow traffic. The updated route may be longer than the previous planned route. However, the expected time of arrival (ETA) at the destination for each alternative route may be included in the data obtained from the navigational system 16 and may affect the selection of the updated route. A significantly delayed time of arrival at the destination is usually not preferred and may cause some alternative routes to be rejected by the processor unit 1.

[0052] The data on the upcoming downhill road section may further comprise traffic information obtained from other vehicles or through telematics, such as from road sensors or other monitoring devices with which the processor device 1 of the fuel cell electric vehicle 3 may be communicatively connected. Data acquired from other vehicles in operation along the route may include more recent and reliable data generated by recent traffic events which are encountered by other vehicles or, for instance, reported from road sensors.

[0053] The selected updated route may be provided to a user of the fuel cell electric vehicle 3, or to an autonomous control system of the fuel cell electric vehicle 3, as a suggested route. The user or the autonomous control system is then able to accept or reject the suggested route, allowing the possibility of various other considerations to affect the selection of the updated route.

[0054] The predicted state of energy Pred may be predicted based on data from the navigational system 16 of the fuel cell electric vehicle 3 combined with GPS and/or GNSS data received by the fuel cell electric vehicle 3. Thereby, a more accurate prediction of the state of energy by the combination of location of the fuel cell electric vehicle 3 with road information, i.e. inclination of the road, curvature, etc. Data on characteristics of the fuel cell electric vehicle 3 may also be included to further improve the prediction of the state of energy.

[0055] The selection of the updated route may further be based on historical data on routes travelled by the fuel cell electric vehicle 3. The historical data may be continuously collected and stored by the fuel cell electric vehicle 3 when travelling. The computer system 800 and/or the processor device 1 may thereby learn consumption of energy, traffic patterns, weather conditions, topography, etc along routes frequently travelled by the fuel cell electric vehicle 3. Optionally, the historical data may comprise data collected by other similar fuel cell electric vehicles. Predictions based on historical data may be more accurate than other available data.

[0056] FIG. 3 shows an exemplary driving scenario of the fuel cell electric vehicle 3. When driving along a planned route, the processor device 1 of the computer system 800 of the fuel cell electric vehicle 3 obtains data on an upcoming downhill road section between point B and point C. The maximum preferred state of energy MPref for the downhill road section is determined. If the state of energy of the electric energy storage system 14 of the fuel cell electric vehicle 3 is below the maximum preferred state of energy MPref at the start of the downhill road section, the regenerative braking performance will have maximum effect, i.e. regenerative braking may be performed along the whole downhill descent. A maximum possible state of energy MSoE represents the maximum charge capacity of the electric energy storage system 14. If the state of energy of the electric energy storage system 14 reaches the maximum possible state of energy MSoE during downhill descent, regenerative braking is disabled and the service brakes of the vehicle will have to be used, with the risk of overheating of the brakes resulting in possibly unsafe driving conditions. As exemplified in FIG. 3, the state of energy of the electric energy storage system 14 at point C, i.e. at the end of the downhill road section, is below the maximum possible state of energy MSoE, which means that regenerative braking is enabled during the whole downhill descent. [0057] FIG. 4 illustrates a scenario where the processor device 1 of the fuel cell electric vehicle 3 has identified slow traffic between its current position at point A and the start of the downhill road section at point B. The diagram predicts a high state of energy Pred at the start of the downhill road section. The predicted state of energy Pred is higher than the maximum preferred state of energy MPref. This would result in the regenerative braking being disabled during descent of the downhill road section. Accordingly, the processor device 1 will perform the action S4 of searching for at least one alternative route to the downhill road section.

[0058] FIG. 5 illustrates another potential problem in case the fuel cell electric vehicle 3 should continue along the route between point A and point B, which experiences slow traffic. As shown in the diagram, the fuel cell unit 12 will produce more power than consumed by the fuel cell electric vehicle 3. When the maximum possible state of energy MSoE is reached, the fuel cell unit 12 is switched off. After the state of energy has decreased to a predetermined level, the fuel cell unit 12 is switched on again. Even though the state of energy at point B is below the maximum preferred state of energy MPref, repeated starts and stops of the fuel cell unit 12 should be avoided in order to not shorten the life of the fuel cell unit 12. Starts and stops of the fuel cell unit may be avoided by the processor unit 1 estimating if the fuel cell unit 12 will be switched off at least once before the start of the downhill road section at point B. If the fuel cell unit 12 is estimated to be switched off, an alert may be generated for the planned route and/or for the at least one alternative route, respectively, such that a user or an autonomous control system of the fuel cell electric vehicle 3 may make a decision on selecting or discarding said route.

[0059] FIG. 6 shows a scenario in accordance with the second aspect of the disclosure. When the predicted state of energy Pred has been determined to exceed the maximum preferred state of energy MPref, an alternative route is identified, and an alternative predicted state of energy is determined for the alternative route. As shown in the diagram, the alternative route allows the electric energy storage system 14 to keep a relatively low state of energy until arriving at the start of the downhill road section at point B .

[0060] In an example shown in FIG. 7, the processor device 1 may form part of a control system 4 comprising one or more processor devices 1, 1’, 1” configured to perform the method 2. The one or more processor devices 1, 1’, 1” may be communicatively connected to each other and configured to send, receive and/ process information and/or data to control and perform the various actions SI, S2, S3, S4, S5 of the method 2. The one or more processor devices 1, 1’, 1” may be control units, or they may be comprised in control units. [0061] FIG. 8 is a schematic diagram of a computer system 800 for implementing examples disclosed herein. The computer system 800 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 800 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 800 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.

[0062] The computer system 800 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 800 may include a processor device 802 (may also be referred to as a control unit), a memory 804, and a system bus 806. The computer system 800 may include at least one computing device having the processor device 802. The system bus 806 provides an interface for system components including, but not limited to, the memory 804 and the processor device 802. The processor device 802 may include any number of hardware components for conducting data or signal processing or for executing computer code stored in memory 804. The processor device 802 (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.

[0063] The system bus 806 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 804 may be one or more devices for storing data and/or computer code for completing or facilitating methods described herein. The memory 804 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 804 may be communicably connected to the processor device 802 (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 804 may include non-volatile memory 808 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.), and volatile memory 810 (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 802. A basic input/output system (BIOS) 812 may be stored in the non-volatile memory 808 and can include the basic routines that help to transfer information between elements within the computer system 800.

[0064] The computer system 800 may further include or be coupled to a non-transitory computer-readable storage medium such as the storage device 814, 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 814 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. [0065] 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 814 and/or in the volatile memory 810, which may include an operating system 816 and/or one or more program modules 818. All or a portion of the examples disclosed herein may be implemented as a computer program product 820 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 814, which includes complex programming instructions (e.g., complex computer-readable program code) to cause the processor device 802 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 802. The processor device 802 may serve as a controller or control system for the computer system 800 that is to implement the functionality described herein.

[0066] The computer system 800 also may include an input device interface 822 (e.g., input device interface and/or output device interface). The input device interface 822 may be configured to receive input and selections to be communicated to the computer system 800 when executing instructions, such as from a keyboard, mouse, touch- sensitive surface, etc. Such input devices may be connected to the processor device 802 through the input device interface 822 coupled to the system bus 806 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 800 may include an output device interface 824 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 800 may also include a communications interface 826 suitable for communicating with a network as appropriate or desired.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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

1. A computer system (800) comprising a processor device (1) for increasing brake performance in a fuel cell electric vehicle (3), the fuel cell electric vehicle (3) comprising a fuel cell unit (12), an electric energy storage system (14), and a navigational system (16), the processor device (1) being configured to: from the navigational system (16), obtain data on an upcoming downhill road section along a planned route of the fuel cell electric vehicle (3), determine a maximum preferred state of energy (MPref) of the electric energy storage system (14) associated with the downhill road section, predict, for the planned route, a predicted state of energy (Pred) that the electric energy storage system (14) will have at a start of the downhill road section, if the predicted state of energy (Pred) exceeds the maximum preferred state of energy (MPref) associated with the downhill road section, identify at least one alternative route to the downhill road section, and predict for the at least one alternative route an alternative state of energy (AltPred) that the electric energy storage system (14) will have at the start of the downhill road section, and select, from among the at least one alternative route and the planned route, an updated route of the fuel cell electric vehicle (3) providing the most efficient regenerative braking performance.

2. A computer- implemented method (2) for increasing brake performance in a fuel cell electric vehicle (3), the fuel cell electric vehicle (3) comprising a fuel cell unit (12), an electric energy storage system (14), a navigational system (16) and a computer system (800) comprising a processor device (1), the method (2) comprising, by the processor device (1): from the navigational system (16), obtaining (SI) data on an upcoming downhill road section along a planned route of the fuel cell electric vehicle (3), determining (S2) a maximum preferred state of energy (MPref) of the electric energy storage system (14) associated with the downhill road section, predicting

(S3), for the planned route, a state of energy (Pred) that the electric energy storage system (14) will have at a start of the downhill road section, if the predicted current state of energy (Pred) exceeds the maximum preferred state of energy (MPref) associated with the downhill road section, searching

(S4) for at least one alternative route to the downhill road section, and predicting for the at least one alternative route an alternative state of energy (AltPred) that the electric energy storage system (14) will have at the start of the downhill road section, and selecting

(S5), from among the at least one alternative route and the planned route, an updated route of the fuel cell electric vehicle (4) providing the most efficient regenerative braking performance. The method (2) of claim 2, wherein the most efficient regenerative braking performance is the regenerative braking providing, during the downhill road section, the highest increase of the state of energy of the electric energy storage system (14) and, if at least two routes provide equivalent increases of the state of energy of the electric energy storage system (14), the most efficient regenerative braking performance is delivered by the route providing the highest state of energy of the electric energy storage system (14) at an end of the downhill road section. The method (2) according to any of claim 2-3, wherein predicting the state of energy for the planned route and/or predicting the state of energy for the at least one alternative route comprises estimating if the fuel cell unit (12) will be switched off at least once before the start of the downhill road section, and if the fuel cell unit (12) is estimated to be switched off, generating an alert for the planned route and/or for the at least one alternative route, respectively. The method (2) of any of claims 2-4, further comprising continuously or intermittently collecting and updating traffic information for the current planned route.

6. The method (2) of claim 5, wherein the data on the upcoming downhill road section comprises the traffic information.

7. The method (2) of claim 5 or 6, wherein the data on the upcoming downhill road section comprises the traffic information obtained from other vehicles or through telematics.

8. The method (2) of any of claims 2-7, wherein the selected updated route is provided to a driver of the fuel cell electric vehicle (3), or to an autonomous control system of the fuel cell electric vehicle (3), as a suggested route.

9. The method (2) of any of claims 2-8, wherein the predicted state of energy (Pred) is predicted based on data from the navigational system (16) of the fuel cell electric vehicle (3) combined with GPS and/or GNSS data received by the fuel cell electric vehicle (3).

10. The method (2) of any of claims 2-9, wherein the selecting (S5) of the updated route is further based on historical data on routes travelled by the fuel cell electric vehicle (3).

11. A fuel cell electric vehicle (3) comprising the processor device (1) to perform the method of any of claims 2-10.

12. A computer program product (820) comprising program code for performing, when executed by the processor device (1), the method of any of claims 2-10.

13. A control system (4) comprising one or more processor devices (1) configured to perform the method of any of claims 2-10.

14. A non-transitory computer-readable storage medium (814) comprising instructions, which when executed by the processor device (1), cause the processor device (1) to perform the method of any of claims 2-10.