Patent Publication Number: US-2023143467-A1

Title: Method and Device for Supporting a Refueling Process of a Vehicle Having a Fuel Cell

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a 371 of International Application No. PCT/EP2021/056141, filed Mar. 11, 2021 which claims priority under 35 U.S.C. § 119 from German Patent Application No. 10 2020 110 008.6, filed Apr. 9, 2020, the entire disclosure of which is herein expressly incorporated by reference. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The technology disclosed herein relates to a method and a corresponding device for supporting a user of a vehicle having a fuel cell system or having a fuel cell in a refueling process. 
     An electrically driven vehicle can comprise a fuel cell system with a fuel cell which is configured to generate electrical energy for an electric drive motor of the vehicle on the basis of a fuel cell, in particular on the basis of hydrogen. The vehicle comprises a tank, in particular a pressure tank, for holding the fuel, wherein the tank can be filled with fuel as part of a refueling process at a refueling station. 
     Before a refueling process, a switch-off process of the fuel cell system, in particular of the fuel cell, is typically carried out in order to allow a safe refueling process. The switch-off process can also be referred to as a shutdown. The switch-off process can take a relatively long time, especially at relatively low ambient temperatures (around or below freezing), which means that the user of the vehicle has to wait a relatively long time for the switch-off process to be completed before the refueling process can be started. 
     It is a preferred object of the technology disclosed herein to reduce or eliminate at least one disadvantage of a previously known solution or to propose an alternative solution. In particular, it is a preferred object of the technology disclosed herein to reduce the waiting time before starting a refueling process of a vehicle having a fuel cell. Further preferred objects may result from the advantageous effects of the technology disclosed herein. The object is achieved by the subject matter of the independent claims. The dependent claims describe preferred embodiments. 
     According to one aspect, a device for supporting a refueling process of a vehicle having a fuel cell is described. The fuel cell can be supplied with a fuel, in particular hydrogen, or rather H 2 . As part of the refueling process, fuel can be added to a fuel tank of the vehicle to increase the fill level of the fuel tank. 
     Before starting the refueling process, typically (for example for safety reasons) a switch-off process of the fuel cell has to be carried out. This switch-off process can take a relatively long time, especially at relatively low ambient temperatures (for example at 5° C. or less), since in this case a so-called winter switch-off process and/or a conditioning of the fuel cell has to be carried out. 
     The device is designed to determine that a refueling process shall be carried out. In particular, the device can be designed to determine that a refueling process shall be carried out during the current stop of the vehicle (if the vehicle is already stationary) or at the vehicle&#39;s next stop ahead (if the vehicle is still moving). Furthermore, the device can be designed to determine a time period ahead and/or a location ahead, in the direction of travel of the vehicle, at which the refueling process shall be carried out. 
     The device can be designed to determine fill level information relating to the fill level of the fuel tank of the vehicle (indicating, for example, that the vehicle will need to be refueled in the relatively near future because the fill level is below a fill level threshold value). Alternatively or additionally, the device can be designed to determine navigation information relating to a planned route of the vehicle (indicating, for example, that the vehicle is on its way to a refueling station). Alternatively or additionally, the device can be designed to determine usage information relating to a typical usage of the vehicle in the past (indicating, for example, that the user always refuels the vehicle at a certain time or on a certain day of the week and/or at a certain location). 
     Alternatively or additionally, the device can be designed to determine sensor data relating to the vehicle&#39;s surroundings. The sensor data (in particular the image data of a camera) can indicate, for example, that the vehicle is moving towards a refueling station. Alternatively or additionally, the device can be designed to determine communication data relating to a communication of the vehicle with a refueling station for the refueling process. For example, it can be determined that a fuel pump has been reserved at the refueling station as part of the communication. 
     The device can be designed to determine on the basis of the fill level information, on the basis of the navigation information, on the basis of the usage information, on the basis of the sensor data and/or on the basis of the communication data that (as part of the vehicle&#39;s next stop) a refueling process shall be carried out. In this way, a refueling process ahead can be predicted in a particularly precise manner. 
     Alternatively or additionally, the device can be designed to determine, on the basis of an input (for example a control input and/or a voice input) of the user at a user interface of the vehicle, that (as part of the vehicle&#39;s next stop) a refueling process shall be carried out. For example, the user may have communicated via an input that a refueling process shall be carried out. The input can be made here directly by the user or can be provided in response to a request from the device to the user (for example because a refueling process has been predicted by the device). By including the user, a planned refueling process can be predicted in a particularly precise manner. 
     The device is further designed, in response to it having been determined that a refueling process shall be carried out (as part of the stop already made by the vehicle or the vehicle&#39;s next stop yet to be made), to perform one or more measures aimed at reducing the delay time period for the start of the refueling process that is caused by the switch-off process of the fuel cell. Here, the delay time period may be the duration between the time at which the vehicle is stopped and the earliest possible time for the start of the refueling process (once the switch-off process of the fuel cell has been completed). 
     The (possibly early) recognition of the fact that a refueling process will be carried out as part of the (already made or next) stop of the vehicle (and thus the vehicle is not expected to be permanently parked) makes it possible to carry out one or more measures to reduce the delay time period, so that the comfort for the user of the vehicle can be increased and/or so that the aging of the fuel cell due to the execution of (possibly unnecessary) switch-off processes can be reduced. 
     The device can be designed, as a measure for reducing the delay time period, to prevent a prolonged winter switch-off process if it has been determined that a refueling process shall be carried out (as part of the stop of the vehicle). Alternatively or additionally, the device can be designed, as a measure for reducing the delay time period, to prevent a conditioning of the fuel cell (to remove water residues in the fuel cell) if it has been determined that a refueling process shall be carried out (as part of the stop of the vehicle). The conditioning of the fuel cell can be designed to adjust or regulate the water balance of the fuel cell. In this context, the fuel cell can be dehumidified (in particular at relatively cold temperatures) in order to protect the fuel cell in the stopped state (in particular when parked). The conditioning of the fuel cell can thus comprise the drying or a dehumidification of the fuel cell. 
     The device can in particular be designed to determine temperature information relating to the ambient temperature in the (possibly direct) environment of the fuel cell. It can then be determined on the basis of the temperature information that a winter switch-off process and/or a conditioning (in particular a drying) of the fuel cell is to be carried out (in particular if the fuel cell is switched off for longer than an allowable maximum time period). Here, the allowable maximum time period can be dependent on the ambient temperature. Typically, the allowable maximum time period increases as the ambient temperature increases. The allowable maximum time period can be determined by the device. 
     The device can be designed, for example, to determine that a winter switch-off process and/or a conditioning (in particular a drying or dehumidification) of the fuel cell is to be carried out if it is identified on the basis of the temperature information that the ambient temperature is less than or equal to a specific temperature threshold value (for example 5° C.). 
     The device can also be designed to nevertheless prevent the execution of the winter switch-off process and/or the conditioning (in particular the drying) of the fuel cell if it has been determined that (as part of the stop of the vehicle) a refueling process shall be carried out (and thus it is to be expected that the fuel cell will be reactivated again within the allowable maximum time period). 
     By eliminating the relatively lengthy winter switch-off process and/or the relatively lengthy conditioning of the fuel cell, the delay time period until the possible start of the refueling process can be significantly reduced. Furthermore, the aging of the fuel cell can be reduced. Instead of the winter switch-off process, a normal or standard switch-off process is then typically carried out (in which no or only partial conditioning (in particular drying) of the fuel cell takes place). 
     The device can be designed to check, after execution of the (standard) switch-off process of the fuel cell, whether the fuel cell has been reactivated again at the latest by the end of the allowable maximum time period. Furthermore, the device can be designed to initiate the execution of at least part of the winter switch-off process and/or the (possibly complete) conditioning (in particular drying) of the fuel cell if it is identified that the fuel cell has not been reactivated within the allowable maximum time period. In this way, any detrimental effect on the fuel cell can be reliably avoided. 
     The device can be designed to determine that a refueling process shall be carried out at a time period ahead and/or at a location ahead in the direction of travel of the vehicle. Thus, it can be predicted in advance that (at the next refueling stop) a refueling process shall be carried out. 
     Then, as a measure for reducing the delay time period, the switch-off process of the fuel cell can be caused to start already temporally before the time period ahead and/or already before reaching the location ahead for the refueling process. Thus, the switch-off process can be started already before the vehicle stops and/or already before the refueling station is reached (so that the remaining time of the switch-off process after the vehicle stops can be reduced). The start of the switch-off process of the fuel cell can have the (direct) consequence here that no more electrical energy is generated by the fuel cell. 
     The device can further be designed, as a measure for reducing the delay time period, to cause the electric drive motor of the vehicle to be operated from the start of the switch-off process of the fuel cell (optionally exclusively) with electric energy from the electric energy storage device of the vehicle (for example from a high-voltage storage device) in order to move the vehicle to the location ahead for the refueling process. The vehicle can thus be operated (optionally solely) from the electric energy storage device until it reaches the refueling station. 
     By initiating the switch-off process of the fuel cell in good time, the delay time period until the possible start of the refueling process can be reliably reduced (and possibly completely avoided). 
     The device can be designed to determine the necessary switch-off time for carrying out the switch-off process of the fuel cell. The switch-off time can depend here on the state of the fuel cell and/or on the ambient temperature in the vicinity of the fuel cell. 
     The switch-off process can be started at a time and/or at a location (before reaching the refueling station for the refueling process) dependent on the determined switch-off time. The time and/or the location for the start of the switch-off process of the fuel cell can be determined here depending on the determined switch-off time in such a way that the switch-off process is ended at the exact time when the vehicle stops for the refueling process and/or at the exact time when a user typically wishes to start the refueling process after the vehicle has stopped. In this way, the delay time period can be reduced to zero in a resource-efficient manner. 
     The device can be designed to determine information relating to the duration and/or the distance of a journey following the refueling process. This information may be determined, for example, on the basis of navigation information and/or on the basis of usage information of the vehicle. The device can further be designed to carry out or prevent a reactivation of the fuel cell following the refueling process depending on the determined information. In particular, a reactivation of the fuel cell can be prevented during a relatively short journey following the refueling process. Thus, the aging of the fuel cell due to the execution of switch-off processes can be reduced. 
     According to a further aspect, a (road) motor vehicle (in particular a passenger car or a truck or a bus) comprising the device described in this document is described. 
     According to a further aspect, a method for supporting a refueling process of a vehicle having a fuel cell is described, wherein a switch-off process of the fuel cell is to be carried out prior to the refueling process. The switch-off process may, for example, require a switch-off time of between 10 seconds and 60 seconds. The switch-off time may depend here on the state of the fuel cell and/or on the ambient temperature. 
     The method comprises determining that (as part of the current or next vehicle stop) a refueling process shall be carried out. Furthermore, in response thereto, the method comprises a step of performing one or more measures aimed at reducing the delay time period for the start of the refueling process that is caused by the switch-off process of the fuel cell. Here, the one or more measures can be performed selectively (optionally only) in the event that it has been identified that a refueling process shall be carried out when the vehicle is stopped. The one or more measures optionally cannot be carried out if it has been identified that a stop of the vehicle without a refueling process shall be made or is currently being made. 
     According to a further aspect, a software (SW) program is described. The SW program can be designed to be run on a processor and thereby to perform the method described in this document. 
     According to a further aspect, a storage medium is described. The storage medium can comprise an SW program designed to be run on a processor and thereby to carry out the method described in this document. 
     It should be noted that the methods, devices, and systems described in this document can be used alone or in combination with other methods, devices, and systems described in this document. Furthermore, any aspects of the methods, devices, and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined in a variety of ways. 
     The invention will be described hereinafter in greater detail with reference to exemplary embodiments. In the figures 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1   a    shows exemplary components of a vehicle; 
         FIG.  1   b    shows an exemplary system for carrying out a refueling process; and 
         FIG.  2    shows a flow diagram of an exemplary method for carrying out a refueling process of a vehicle having a fuel cell. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     As stated at the outset, the present document is concerned with increasing the convenience of a refueling process for refueling the fuel tank of a fuel cell system of a vehicle. In this context,  FIG.  1   a    shows an exemplary vehicle  100 . The vehicle  100  comprises a fuel tank  103 , in particular a pressure tank, for holding a fuel, in particular hydrogen. The tank  103  can be refueled via a coupling element  102 , which, for a refueling process, is configured to be connected to a complementary coupling element  122  on a refueling hose  121  of a refueling station  120  (see  FIG.  1   b   ). 
     The fuel from the tank  103  can be used to power a fuel cell  104  of the vehicle  100  in order to generate electrical energy that can be stored in an electrical energy storage device  106  of the vehicle  100  and/or that can be used to power an electric drive motor  107  of the vehicle  100 . 
     Typically, before a refueling process of the tank  103  can be carried out, the fuel cell  104  must first be switched off or disconnected. A switch-off process can be carried out for this purpose. The switch-off process can be designed to place the fuel cell  104  in a switched-off state in which the fuel cell  104  is as protected as possible from detrimental effects caused by environmental degradation. 
     The switch-off process can depend on current ambient conditions of the fuel cell  104  or the vehicle  100 . In particular, the switch-off process can include drying the anode of the fuel cell  104  at relatively low ambient temperatures (particularly at or below freezing) to remove water from the fuel cell  104  (which might cause damage to the fuel cell  104  by freezing). Thus, the time period of the switch-off process can be relatively long (for example, 30 seconds or longer), particularly at relatively low ambient temperatures. 
     The switch-off process of the fuel cell  104  can be caused by one or more actuators  105  (for example, a fan). The control unit  101  of the vehicle  100  can be designed to operate the one or more actuators  105  to carry out the switch-off process. Furthermore, the control unit  101  can be designed to identify that the switch-off process has been completed. In response, a refueling process for refueling the fuel tank  103  can be enabled. 
     Carrying out the switch-off process of the fuel cell  104 , particularly at relatively low ambient temperatures, may thus require the user of the vehicle  100  to wait a relatively long time after parking or stopping the vehicle  100  at a refueling station  102  before the refueling process of the tank  103  can be started. This is typically inconvenient for the user of the vehicle  100 . 
     The control unit  101  can be designed to determine that a refueling process should be carried out before reaching a refueling station  120  or upon reaching a refueling station  120 . For example, it can be predicted or determined that a refueling process shall be carried out on the basis of the current fill level of the tank  103 , on the basis of a planned route of the vehicle  100  in a navigation device  108  of the vehicle, on the basis of historical usage data of the vehicle  100 , on the basis of vehicle-to-infrastructure communication (for example, between the vehicle  100  and a refueling station  120 ), or on the basis of the evaluation of sensor data from one or more environmental sensors (in particular cameras) of the vehicle  100 . In particular, it can be predicted that a refueling process of the vehicle  100  will be carried out within a certain time period ahead (for example, of 10 minutes or less). 
     Alternatively or additionally, the user of the vehicle  100  can be allowed to indicate that a refueling process shall be carried out via a user interface  109  of the vehicle  100 . For this purpose, a control input can be made at a control element of the user interface  109  and/or a voice input of the user can be provided. 
     Alternatively or additionally, the user interface  109  of the vehicle  100  can be used to question (for example, in response to the aforementioned prediction of a refueling process ahead) whether or not a refueling process should actually be carried out. It can then be possible for the user to indicate via the user interface  109  (for example, by a control input and/or by a voice input) whether or not a refueling process should be carried out. 
     The control unit  101  can thus be designed to determine that (within a certain time period ahead) a refueling process of the vehicle  100  shall be carried out. One or more measures can then be performed in order to reduce (or, if possible, avoid altogether) the delay time period between the vehicle  100  being parked at the refueling station  120  and the possible start of the refueling process. 
     An exemplary measure in this regard is to switch off the fuel cell  104  regardless of the ambient temperature and/or even at relatively low ambient temperatures using a (standard) switch-off process for relatively high ambient temperatures. In particular, only a normal or standard switch-off process can be carried out, even in winter (and not the relatively time-consuming winter switch-off process or winter shutdown). It can be assumed here that after the refueling of the tank  103 , the fuel cell  104  is directly restarted or reactivated, so that the fuel cell  104  is not expected to cool down (and thus might be damaged by the remaining water in the fuel cell  104 ). 
     The control unit  101  can be designed to check whether a refueling process is actually carried out and/or whether the fuel cell  104  is reactivated within a specified, allowable, maximum switch-off period. If it is identified that the fuel cell  104  has not been reactivated within the specified stopped period, then the winter switch-off process can be performed subsequently to avoid any detrimental effect to the fuel cell  104 . 
     Alternatively or additionally, as a measure, the switch-off process of the fuel cell  104  can be made to start already during the approach (at a certain physical distance (for example, 100 meters) and/or temporal distance (for example, 30-60 seconds)) prior to reaching the refueling station  120 . The vehicle  100  can then be operated the remaining distance to the refueling station  120  (optionally solely) based on the electrical energy from the electrical energy storage device  106 . In this way, the switch-off process can thus be finished before the user wishes to begin the refueling process. 
     The control unit  101  can be designed to determine the distance that the vehicle  100  will travel following the refueling process until the vehicle  100  is stopped again. For example, it can be determined that the vehicle  100  will travel to the user&#39;s residence following the refueling process. 
     If it is identified that only a relatively short distance will be traveled following the refueling process, which can be traveled solely using electrical energy from the electrical energy storage device  106 , then the restart of the fuel cell  104  can be prevented. In this way, a re-execution of the switch-off process, the associated energy consumption, and the associated aging of the fuel cell  104  can be avoided. 
       FIG.  2    shows a flow diagram of an exemplary (possibly computer-implemented) method  200  for supporting a refueling process of a vehicle  100  having a fuel cell  104 . In a vehicle  100  having a fuel cell  104 , it is typically necessary to perform a switch-off process of the fuel cell  104  before starting the refueling process. In this regard, the switch-off process may take a relatively long period of time, particularly in winter or at relatively low temperatures (in order to perform a drying of the fuel cell). 
     The method  200  comprises determining  201  that a refueling process shall be carried out. For this purpose, data from a navigation system  108  of the vehicle  100 , for example, and/or data relating to the fill level of the fuel tank  103  of the vehicle  100  and/or a user input at a user interface  109  of the vehicle  100  can be considered and/or evaluated. In particular, it can be determined within the scope of the method  200  that the vehicle  100  will perform a refueling process during the stop that has already been made or at the next stop. 
     Furthermore, in response thereto, the method  200  comprises performing  202  one or more measures aimed at reducing the delay time period for the start of the refueling process caused by execution of the switch-off process of the fuel cell  104 . In other words, the one or more measures may help to start the refueling process as soon as possible after the vehicle is stopped so that the user does not have to wait for the switch-off process of the fuel cell to complete, or only has to wait for a reduced time period. 
     To reduce the delay time period between the stopping of the vehicle and the possible start of the refueling process, the switch-off process can be started already while the vehicle is still moving, before it reaches the refueling station for the refueling process. Alternatively or additionally, instead of a winter switch-off process, a normal or standard switch-off process can be carried out (wherein the standard switch-off process is typically quicker than the winter switch-off process), even if it would seem necessary to carry out the winter switch-off process due to the temperature conditions in the environment of the vehicle. 
     The method  200  described in this document can accelerate the readiness for refueling of a vehicle  100  having a fuel cell  104 . Furthermore, the number of winter switch-off processes of a fuel cell  104 , the associated load or aging of the fuel cell  104 , and the associated energy consumption can be reduced. Thus, the service life of a fuel cell  104  can be increased. 
     Within the scope of a switch-off process, water may be purged from the exhaust system of the fuel cell  104 , if necessary, which may result in water accumulation on the ground at the refueling station  120  and possibly ice formation in winter (especially if multiple vehicles  100  are refueled in succession at the same refueling station  120 ). By performing the switch-off process in good time before reaching the refueling station  120 , such water accumulations can be avoided or at least reduced. 
     The present invention is not limited to the exemplary embodiments shown. In particular, it should be noted that the description and figures are intended to illustrate the principle of the proposed methods, devices and systems merely by way of example.