Method for shifting a transmission of an electrically driven vehicle having a fuel cell system, in particular a commercial vehicle, computer program and / or computer-readable medium, control unit, vehicle

Abstract

Method (300) for shifting (256) a transmission (255) of an electrically driven vehicle (200a) having a fuel cell system (205), in particular a commercial vehicle (200b), the method (300) comprising: detecting (310) a shift request (257) for shifting (256) the transmission (255); determining (320) a target power variable (261) characterizing a power (P) of the fuel cell system (205) during the shifting (256); and outputting (330) a power adjustment signal (260) for adjusting the power of the fuel cell system (205) to the target power variable (261) during the shifting (256).

Description

[0001] The disclosure relates to a method for shifting a transmission of an electrically driven vehicle, in particular a commercial vehicle, having a fuel cell system. The disclosure also relates to a computer program and / or computer-readable medium, a control unit for an electrically driven vehicle, in particular a commercial vehicle, having a transmission and a fuel cell system, and a vehicle, in particular a commercial vehicle, comprising a fuel cell system, an electric drive with a transmission, and a control unit.

[0002] Such electrically powered vehicles, particularly commercial vehicles, with a fuel cell system are known in the art. Such a vehicle, particularly a commercial vehicle, is also referred to as a fuel cell electric vehicle (FCEV). In the following, the term "vehicle" will be used for short, including for a commercial vehicle.

[0003] The power components of such a vehicle include, for example, in particular the fuel cell system, an electric drive for propelling the vehicle, an optional brake resistor (BR), and an energy storage device for storing and providing electrical energy. The vehicle includes a high-voltage network, also referred to as the vehicle electrical system, which electrically couples the fuel cell system, the drive, the brake resistor, and the energy storage device—i.e., the power components.

[0004] The fuel cell system is known from the prior art. Such a fuel cell system comprises galvanic cells that can be used to convert chemical energy into electrical energy. The electrical energy is generated from a so-called fuel cell reaction, a chemical reaction between a supplied fuel, for example hydrogen, and an oxidizing agent, usually oxygen. To increase energy generation, several fuel cells can be combined in a fuel cell arrangement or fuel cell stack. In addition to the fuel cell stack, the fuel cell system typically comprises other components, such as a compressor or compressor for supplying the oxidizing agent or air to the cathode side of the fuel cell stack.

[0005] The electric drive typically comprises at least one electric motor, power electronics and a transmission.

[0006] The braking resistor is designed to convert electrical energy into heat. This allows, for example, the vehicle's mechanical energy through regenerative braking and / or continuous braking to be converted into electrical energy, and electrical energy can be converted into heat.

[0007] According to the current state of the art, the fuel cell system can supply power to the high-voltage network, while the braking resistor can only draw power from the high-voltage network. The electric drive can draw power from the high-voltage network during vehicle acceleration and can supply power to the high-voltage network during deceleration through regenerative braking. The energy storage device draws power from the high-voltage network when charging the energy storage device and supplies power to the high-voltage network when discharging the energy storage device.

[0008] The performance of the energy storage device depends on a number of influencing factors, including the state of charge (SOC) of the energy storage device, various environmental parameters (particularly temperature) and the state of health (SOH) of the energy storage device, as well as the basic configuration, in particular the type and interconnection of the cells.

[0009] The performance of the other components connected to the high-voltage network is also subject to restrictions. Thus, the power components of a fuel cell vehicle—i.e., the fuel cell system, the electric drive, the energy storage device, and the braking resistor—have different power dynamics: The braking resistor, drive, and energy storage device components exhibit comparatively high power dynamics, meaning that the power flow of the components can be changed with high temporal gradients; the fuel cell system, in contrast, exhibits lower power dynamics, meaning that the power flow of the fuel cell system can only be changed with a comparatively small temporal gradient.

[0010] During shifting of the electric drive, the transmission can or must be synchronized with the help of the electric motor, depending on the design of the transmission. This means that when shifting from a gear G1 to a gear G2, the speed of a transmission input is adjusted from the speed in gear G1 to the speed in gear G2 with the help of the electric motor coupled to the transmission input. The speed adjustment to be carried out at the transmission input depends on the speed at a transmission output and the gear ratios of gears G1 and G2 (in particular: old speed: n_drive1 = i_G1*n_output; new speed: n_drive2 = i_G2*n_output, where n_output is the speed at the transmission output, i_G1 is the gear ratio of gear G1, and i_G2 is the gear ratio of gear G2).Depending on the gearshift, specifically gears G1 and G2, and the gearshift type, the synchronization can result in high electrical power being fed or introduced from the electric drive into the high-voltage network (e.g. traction-interrupted upshift: braking of the transmission input) or being withdrawn or removed from the high-voltage network (e.g. traction-interrupted downshift: acceleration of the transmission input).

[0011] Depending on the configuration of the components coupled to the high-voltage network, in particular a capacity of the energy storage device, charging and / or discharging rates of the energy storage device, the performance of the fuel cell system and its current state (state of charge and / or aging of the energy storage device, current performance of the components), the resulting comparatively high power of the electric drive, which is introduced into the high-voltage network during synchronization and / or withdrawn from the high-voltage network, may not be absorbed by the energy storage device and / or provided by the energy storage device and the fuel cell system.

[0012] For illustration purposes, two scenarios are presented below.

[0013] Scenario 1: The energy storage device has a comparatively high state of charge and the fuel cell system is running at a comparatively high power. Due to the high state of charge, the energy storage device has a low charging capacity and can therefore only absorb comparatively little power from the high-voltage grid. At the same time, the fuel cell system feeds a high power into the high-voltage grid. If a highly dynamic shift occurs in this state, in which power from the electric drive is fed into the high-voltage grid (e.g., during an upshift of an automated manual transmission and / or a traction-interrupted shift), the energy storage device can no longer absorb the power in addition to the power of the fuel cell system. To prevent the high-voltage grid from being overloaded, part of the electrical energy must be dissipated to the environment in the form of heat via the braking resistor.This leads to reduced efficiency.

[0014] Scenario 2: The energy storage device has a comparatively low state of charge, and the fuel cell system is running at a comparatively low power output. Due to the low state of charge, the energy storage device has a low discharge capacity and can therefore supply little power to the high-voltage grid. At the same time, the fuel cell system only supplies a small amount of power to the high-voltage grid. If a highly dynamic shift occurs in this state, in which power from the electric drive is drawn from the high-voltage grid (e.g., downshifting of an automated manual transmission and / or a traction-interrupted shift), the available power in the high-voltage grid is insufficient to synchronize the transmission of the electric drive with the electric motor.In this case, synchronization must be performed over a longer period of time to reduce the maximum required synchronization power. This increases the shifting time and thus reduces shifting comfort.

[0015] Based on what has been described, including the two scenarios, it becomes clear that it is possible to coordinate a switching operation or switching in order to achieve energy efficiency and comfort.

[0016] DE 10 2013 222 972 A1 discloses a GPS-based predictive shift schedule for an automatic transmission. A method for modifying a default transmission shift schedule for a vehicle includes monitoring current vehicle parameters and determining future road information at a predetermined distance ahead of the vehicle. Future vehicle parameters are predicted based on the determined future road information. The default transmission shift schedule is modified based on the current vehicle parameters and the predicted future vehicle parameters.

[0017] Intelligent condition prediction can also be used to operate vehicles efficiently. DE 10 2011 018 182 A1 discloses a self-learning, satellite navigation-assisted hybrid vehicle control system. The self-learning control unit uses information to make predictions about the vehicle's future driving conditions in order to efficiently utilize the hybrid vehicle's power sources. CN 113859053 A discloses a fuel cell management method.The driving request-based fuel cell management method includes the following steps: receiving driving request information input by a driver; obtaining a feasible path and predicted vehicle overtaking data according to the driving request information; making predictions based on the vehicle predicted traffic data and the vehicle performance parameters to obtain a predicted driving state of the vehicle; and controlling the power output of the fuel cell according to the predicted driving state of the vehicle.

[0018] Against the background of this prior art, one object of the present disclosure is to enable shifting of a transmission of an electrically driven vehicle, in particular a commercial vehicle, having a fuel cell system, wherein the shifting is suitable for enriching the prior art and improving at least the above-mentioned aspects of the prior art. In particular, the object of the disclosure is to enable improved shifting of a transmission of an electrically driven vehicle, in particular a commercial vehicle, having a fuel cell system, in order to avoid inefficient power output to the environment and / or to increase shifting comfort.

[0019] The problem is solved by the features of the independent claims. The subclaims contain further developments of the disclosure.

[0020] According to one aspect of the disclosure, the object is achieved by a method for shifting a transmission of an electrically driven vehicle, in particular a commercial vehicle, having a fuel cell system, the method comprising: detecting a shift request for shifting the transmission; determining a target power variable characterizing a power of the fuel cell system during the shift; and outputting a power adjustment signal for adjusting the power of the fuel cell system to the target power variable during the shift.

[0021] The disclosure provides a predictive mechanism for gear determination, but not with the aim of optimizing the shifting time as known from the prior art, but rather with the aim of adapting the power of the energy sources for the shifting in order to perform the shifting as efficiently and conveniently as possible. In particular, it is proposed to adapt the power of the fuel cell system before and during the shifting. Accordingly, the power of the fuel cell system during the shifting should have a power defined by the target power value.

[0022] It was recognized that adjusting the power of the fuel cell system before shifting has a particular influence on the power dynamics of the vehicle components connected to a high-voltage network, since the fuel cell system typically has lower dynamics than, for example, an electric drive, the energy storage device, and / or an optional braking resistor. The method specifically relates to the state of the gear change as defined by the shift request in order to efficiently distribute the power of the energy sources of a fuel cell vehicle.

[0023] By using this process, no or less power needs to be released into the environment, for example, through heat conversion and heat dissipation. This can improve the efficiency of gearshifting and thus the vehicle's driving performance. Furthermore, by using this process, it is possible to eliminate the need to increase the gearshift duration, thus increasing gearshift comfort.

[0024] The method is specifically applicable to fuel cell vehicles, but generally also to vehicles with, in addition to the energy storage device, other electrical components coupled to the high-voltage network that have lower power dynamics than the energy storage device.

[0025] Optionally, the gearshift request has a first target time for shifting the transmission, and the power adjustment signal is output such that the target power variable is set at the first target time and / or at a second target time different from the first target time. It was recognized that the gearshift request can define the first target time, i.e. a required or desired time for shifting. Depending on the type and method, in particular one of several options, efficiency and / or comfort can be increased if the first target time is not adhered to, but the gearshift takes place at a second target time after the first target time. In certain cases, for example if safety is relevant, the first target time may have to be adhered to.

[0026] Optionally, the method comprises checking, based on the first target time, the power adjustment signal and / or the second target time. It was recognized that checking the power adjustment signal and / or the second target time can influence the output of the power adjustment signal: The checking can result in the power adjustment being unnecessary, for example, at the second target time, due to an excessive loss of efficiency.

[0027] Optionally, the target performance indicator is determined according to one of several options. It was recognized that, depending on the scenario, situation, or circumstance, it may be appropriate to determine the target performance indicator from different perspectives defined by the options.

[0028] Optionally, the multiple options include an efficiency- and / or comfort-optimized shift option and / or a shift-time-optimized shift option. It was recognized that an efficiency- and / or comfort-optimized shift option can contribute to improved efficiency and / or comfort. The shift-time-optimized shift option can enable the shift to occur as precisely as possible at the first target time.

[0029] Optionally, the target power value is determined such that an electric drive of the vehicle, in particular a commercial vehicle, provides a greater power boost when switching compared to the actual state. It was recognized that the electric drive can contribute particularly significantly to loading and / or unloading the high-voltage network and that the electric drive also has comparatively high dynamics. Therefore, switching can be coordinated with regard to the electric drive. The actual state is defined by the power of the electric drive. The power boost refers to a power difference between the actual state and the state of the electric drive during switching. The power boost can refer to the extraction of electrical energy from the high-voltage network, for example when driving the vehicle.The power boost can refer to the feeding of electrical energy into the high-voltage network, for example during regenerative braking.

[0030] Optionally, the method includes checking the switching request taking into account the target power value. It was recognized that checking the power adjustment signal and / or the second target time can influence a switching decision: The check may result in the conclusion that switching at the second target time is unnecessary, for example, due to an excessive loss of efficiency.

[0031] Optionally, the method includes testing the performance of the fuel cell system. It was recognized that, due to the comparatively low dynamic range, there may be a time lag between the output of the power adjustment signal and the achievement of the power defined by the target power variable. Switching should occur when the target power variable is reached and / or approximated, which can be determined by testing the performance of the fuel cell system.

[0032] Optionally, the method includes outputting a shift signal for shifting the transmission. This allows the shift to be performed. The features described so far prepare the shifting of the transmission, i.e., shifting in the narrower sense, and therefore belong to the shifting process, i.e., shifting in the broader sense.

[0033] Optionally, the method comprises outputting a second power adjustment signal for adjusting the power of the fuel cell system to a normal power level after switching. It was recognized that, after switching, the fuel cell system can again assume a power level defined by the normal power level.

[0034] Optionally, the switching request includes a safety indicator indicating the safety relevance of the switching, and the determination of the target power value and / or the output of the power adjustment signal takes place taking the safety indicator into account. It has been recognized that, under certain circumstances, immediate switching is necessary, for example, to avoid overloads and / or to comply with regulations governing the operation of the vehicle. The safety indicator describes or indicates such a circumstance, for example, in order to align the power adjustment of the fuel cell system accordingly and / or to make it unnecessary.

[0035] According to one aspect of the disclosure, a computer program and / or a computer-readable medium is provided. The computer program and / or the computer-readable medium comprise instructions which, when the program or instructions are executed by a control unit, cause the control unit to perform the method according to the disclosure and / or steps thereof. Optionally, the computer program and / or the computer-readable medium comprises instructions which, when the program or instructions are executed by a control unit, cause the control unit to perform the method steps described as advantageous or optional in order to achieve an associated technical effect.

[0036] According to one aspect of the disclosure, a control unit is provided for an electrically driven vehicle, in particular a commercial vehicle, having a transmission and a fuel cell system. The control unit is configured to carry out the method described above. Optionally, the control unit is configured to carry out a method step described as advantageous or optional and / or to implement a method feature in order to achieve an associated technical effect.

[0037] According to one aspect of the disclosure, a vehicle, in particular a commercial vehicle, comprising a fuel cell system, an electric drive with a transmission, and the control unit described above is provided. Optionally, the control unit of the vehicle, in particular a commercial vehicle, and / or the vehicle, in particular a commercial vehicle, is configured to perform a method step described as advantageous or optional and / or to implement a method feature in order to achieve an associated technical effect.

[0038] In the following, one embodiment is described with reference to the figures. Fig. 1 schematically shows a vehicle, in particular a commercial vehicle, according to one aspect of the disclosure; Fig. 2 schematically shows features of a vehicle, in particular a commercial vehicle, according to one aspect of the disclosure; Fig. 3 schematically shows a flow diagram of a method according to one aspect of the disclosure; Fig. 4 schematically shows features of a method according to one aspect of the disclosure; and Fig. 5 shows a schematic representation of a computer program and / or computer-readable medium according to one aspect of the disclosure.

[0039] Fig. 1 schematically shows a vehicle 200a, in particular commercial vehicle 200b, according to one aspect of the disclosure.

[0040] The vehicle 200a, in particular the commercial vehicle 200b, is referred to below as vehicle 200a, 200b. The vehicle 200a, 200b is, for example, a land vehicle or a watercraft.

[0041] The vehicle 200a, 200b comprises a fuel cell system 205, a control unit 222, and an electric drive 250 with a transmission 255. The transmission 255 is, for example, an electrodynamic transmission (EDS), i.e., a traction-maintaining transmission, or an automated manual transmission (AMT), i.e., a traction-interrupted transmission. The electric drive 250 is configured to convert electrical energy 65 into mechanical energy and, via the transmission 255, to convert it into mechanical energy of the vehicle 200a, 200b.

[0042] The fuel cell system 205 comprises a fuel cell stack with a cathode and an anode and may also include a fuel cell control unit (not shown). A compressor assembly (not shown) is configured to supply an air flow to the cathode side of the fuel cell stack. For this purpose, the compressor assembly is configured to be supplied with electrical energy 65 to draw in air, compress it, and supply it to the fuel cell stack as supply air.

[0043] The vehicle 200a, 200b also has an energy storage device 230. The fuel cell system 205 is configured to provide electrical energy 65 to the energy storage device 230. The energy storage device 230 is, for example, a rechargeable energy storage device 230 and is designed as a buffer battery for buffering electrical energy 65 and / or for cushioning power peaks. The energy storage device 230 is a so-called traction battery. The energy storage device 230 is connected to the electric drive 250 in order to supply the electric drive 250 with electrical energy 65 so that the electric drive 250 can drive the vehicle 200a, 200b. In addition, the electric drive 65 is configured for regenerative braking in order to be able to convert mechanical energy into electrical energy 65 and thus optionally charge the energy storage device 230.A voltage converter (not shown) is provided between the fuel cell system 205 and the energy storage device 230 and between the energy storage device 230 and the electric drive 250.

[0044] The vehicle 200a, 200b has a vehicle network 210 or high-voltage network and a braking resistor 215 (see Fig. 2). The fuel cell system 205, the electric drive 250, and the energy storage device 230 are connected for transmitting electrical energy 65 through the vehicle network 210 and are also referred to as components of the vehicle network 210, as components connected to the vehicle network 210, and / or as components.

[0045] The control unit 222 and / or the vehicle 200a, 200b is configured to Fig. 3 and Fig. 4 described method 300. The control unit 22 according to Fig. 1 is, for example, a drive, circuit and / or fuel cell system control unit.

[0046] The control unit 222 is communicatively connected to the fuel cell system 205, the electric drive 250, the transmission 255, and the energy storage device 230. Through the communicatively connected connection, the control unit 222 can acquire information concerning the components and / or output signals to the components for monitoring, controlling, and / or regulating the components.

[0047] The control unit 222 is configured to detect a shift request 257 for shifting 256 of the transmission 255. The shift request 257 can be triggered, for example, by a driver of the vehicle 200a, 200b and / or an automated driving function. The shift request 257 has a first target time t1 for shifting 256 of the transmission 255. Furthermore, the shift request 257 can include a safety indicator 281 indicating a safety relevance 280 of the shift 256.

[0048] The control unit 222 is configured to determine a power P of the fuel cell system 205 during the switching 256 from a target power variable 261. The target power variable 261 may be different from a current power P of the fuel cell system 205. The power P of the fuel cell system 205 is therefore to be changed from an actual state at a current time, for example from a power P defined by a normal power variable 266, to the power P defined by the target power variable 261 at a future first target time t1.

[0049] The target power variable 261 is determined in such a way that the electric drive 250, when switching 256, has a power stroke 252 that is increased compared to an actual state 251 (see Fig. 4) provides.

[0050] The control unit 222 is configured to output a power adjustment signal 260 for adjusting the power of the fuel cell system 205 to the target power value 261 during switching 256. The power adjustment signal 260 controls the fuel cell system 205 such that the target power value 261 is assumed and / or approximated during switching 256. The power adjustment signal 260 thus leads to a change in the power P of the fuel cell system 205.

[0051] The determination of the target power quantity 261 and / or the output 330 of the power adjustment signal 260 can be carried out taking into account the safety indicator 281 (see description of Fig. 4).

[0052] The control unit 222 is configured to output a shift signal 258 for shifting 256 the transmission 255. This causes the shifting 256 of the transmission 255 to occur. The shift signal 258 coordinates the shifting 256 in time and defines a change in a transmission ratio and / or reduction ratio of the transmission 255.

[0053] The control unit 222 is configured to output a second power adjustment signal 265 for adjusting the power P of the fuel cell system 205 to a normal power value 266 after the switching 256.

[0054] Fig. Figure 2 schematically shows features of a vehicle 200a, in particular a commercial vehicle 200b, according to one aspect of the disclosure. The vehicle 200a, in particular a commercial vehicle 200b, is thus with reference to Fig. 1 described vehicle 200a, 200b. Fig. 2 is made with reference to Fig. 1 described.

[0055] Fig. 2 illustrates the vehicle network 210 and the components electrically connected and / or connectable to the vehicle network 210: the braking resistor 215, the fuel cell system 205, the electric drive 250 and the energy storage device 230.

[0056] The arrows in Fig. 2 illustrate a possible flow of electrical energy 65.

[0057] An arrow from one of the components to the high-voltage network 210 indicates an introduction or feeding of electrical energy 65 by the respective component into the high-voltage network 210. For example, the electric drive 250 can introduce electrical energy 65 into the high-voltage network 210 during regenerative braking and / or the energy storage device 230 can introduce electrical energy 65 during discharging of the energy storage device 230. Energy 65 introduced through regenerative braking can be used to charge the energy storage device 230. Electrical energy 65 introduced during discharging of the energy storage device 230 can be used to operate the remaining components. The fuel cell system 205 can feed in electrical energy 65 by carrying out the fuel cell reaction.

[0058] An arrow from the high-voltage network 210 to one of the components indicates the extraction of electrical energy 65 by the respective component from the high-voltage network 210. For example, the electric drive 250 can extract electrical energy 65 to convert it into mechanical energy. The braking resistor 215 can extract electrical energy 65 and convert it into heat. The energy storage device 230 can extract electrical energy 65 to charge the energy storage device 230.

[0059] The components, i.e., the fuel cell system 205, the electric drive 250, the energy storage device 230, and the braking resistor 215, have different power dynamics: The components braking resistor 215, drive 250, and energy storage device 260 have comparatively high power dynamics; the fuel cell system 205, on the other hand, has lower power dynamics.

[0060] During the shifting of the electric drive 250, the transmission 255 must be synchronized. This can result in high electrical power being fed from the electric drive 250 into the high-voltage network 210 or being drawn from the high-voltage network 210.

[0061] Fig. 3 schematically shows a flow diagram of a method 300 according to one aspect of the disclosure. The method 300 according to Fig. 3 is a method 300 for shifting 256 a transmission 255 of an electrically driven vehicle 200a, in particular a commercial vehicle 200b, having a fuel cell system 205. Such a vehicle 200a, in particular a commercial vehicle 200b, and its features are described with reference to Fig. 1 and Fig. 2 described. Fig. 3 is made with reference to Fig. 1 and Fig. 2 described.

[0062] The procedure 300 according to Fig. 3 comprises: detecting 310 a shift request 257 for shifting 256 the transmission 255.

[0063] The shift request 257 has a first target time t1 for shifting 256 of the transmission 255.

[0064] The switching request 257 may include a safety indicator 281 indicating a safety relevance 280 of the switching 256.

[0065] The method 300 comprises: determining 320 a target power variable 261 characterizing a power P of the fuel cell system 205 during the switching 256.

[0066] The target power variable 261 is determined according to one of several options 270. The several options 270 include an efficiency- and / or comfort-optimized switching option 271 and / or a switching-time-optimized switching option 272.

[0067] The target power variable 261 is determined such that an electric drive 250 of the vehicle 200a, in particular commercial vehicle 200b, provides a power stroke 252 that is increased compared to an actual state 251 during switching 256.

[0068] The method 300 comprises: outputting 330 a power adjustment signal 260 for adjusting the power of the fuel cell system 205 to the target power value 261 during the switching 256.

[0069] The determination 320 of the target power quantity 261 and / or the output 330 of the power adjustment signal 260 can be carried out taking into account the safety indicator 281.

[0070] The power adjustment signal 260 is output such that the target power quantity 261 is set at the first target time t1 and / or at a second target time t2 different from the first target time t1.

[0071] The method 300 includes: checking 335, based on the first target time t1, the power adjustment signal 260 and / or the second target time t2.

[0072] The method 300 comprises: checking 336 the switching request 257 taking into account the target power quantity 261.

[0073] The method 300 includes: checking 345 the power P of the fuel cell system 205.

[0074] The method 300 includes: outputting 350 a shift signal 258 for shifting 256 the transmission 255.

[0075] The method 300 comprises: outputting 360 a second power adjustment signal 265 for adjusting the power P of the fuel cell system 205 to a normal power value 266 after the switching 256.

[0076] The person skilled in the art will recognize that the method 300 according to Fig. 3 can also be performed in a different order than that shown. In particular, it is possible for steps of method 300 to be interchanged, shifted, and / or performed simultaneously.

[0077] Fig. 4 schematically shows features of a method 300 according to one aspect of the disclosure. The features according to Fig. 4 refer to the method 300 according to Fig. 3. Fig. 4 is made with reference to Fig. 1 to 3.

[0078] The features of the method 300 may, as in Fig. 4, can be subdivided into strategic features 291 and operational features 292. The strategic features 291 define when the switching 256 should be executed and under what circumstances, and in particular, the performance conditions. The switching 256 itself is implemented by the operational features 292.

[0079] First, the shift request 257 is detected. Based on the shift request 257, a shift recommendation 259 is derived and / or the shift request 257 includes the shift recommendation 259. The shift recommendation 259 or gear recommendation defines that a shift 256 of the transmission 255 should be performed in the near future. The shift recommendation 259 also defines the first target time t1.

[0080] The shift recommendation 259, or information about the desired type of shift 256, the desired time of shift 256, and the target gear of the transmission 255 to be achieved by the shift 256, is used to determine the target output variable 261. In addition, the safety indicator 281, or the information as to whether the shift 256 is safety-relevant, can be transmitted.

[0081] To determine the target power variable 261, i.e., the power P of the fuel cell system 205 during switching 256, two different options 270 are calculated based on the switching request 257 and / or the switching recommendation 259 with respect to the power distribution of the components connected by the high-voltage network 210. The options 270 include an efficiency- and / or comfort-optimized switching option 271 and a switching-time-optimized switching option 272.

[0082] The efficiency- and / or comfort-optimized switching option 271 depicts the implementation of switching 256, in which the efficiency (see description of scenario 1) or the comfort (see description of scenario 2) is to be improved. In this case, it is calculated how the power P of the fuel cell system 205 must be adjusted before the switching is triggered or before the switching 256 in order to be able to provide an increased power P or an increased power stroke 252 of the electric drive 250 during the switching 256. This can depend on the achievable power gradients of the components and the size of the power stroke 252. In addition, the efficiency- and / or comfort-optimized switching option 271 can lead to a longer duration from the switching request 257 to the switching 256, i.e., to a second target time t2 that is different from the first target time t1.In order to ensure that the switching 256 is permissible at the specific second time t2 which deviates from the switching strategy, the second target time t2 is checked again by checking 336 the switching request 257 and / or the switching recommendation 259.

[0083] The switching time-optimized switching option 272 maps the execution of the switching 256 as closely as possible to the way it is defined by the switching request 257 and / or the switching recommendation 259. This means that, above all, the first target time t1 of the switching initiation or switching 256 should be adhered to, and this may result in losses in efficiency (reducing excess power via braking resistor 215) and / or switching comfort (longer synchronization time). However, even in this case, it must be fundamentally ensured that the power P of the fuel cell system 205 is at least reduced and / or increased to such an extent that the other components in the high-voltage network 210 are not overloaded.

[0084] One of the power distribution options 270 is selected. This can be done according to a wide variety of criteria and can be parameterized according to user requirements. If it is determined that the different second target time t2 is not permissible according to the efficiency- and / or comfort-optimized switching option 271, the switching time-optimized switching option 272 is automatically selected.

[0085] The information about the type of shift 256, the target gear, the duration until the shift 256, the target power variable 261, and the power gradient are further processed to define whether the shift 256 should be triggered with the calculated parameters: thus, a shift decision 275 is made. If consideration of different criteria results in the shift 256 not being triggered, the method 300 begins again with the strategic features 291. If the shift 256 is triggered, the method 300 proceeds from the strategic features 291 to the operative features 292.

[0086] Operationally, the power adjustment signal 260 is output to the fuel cell system 205 in order to adjust the power P of the fuel cell system 205 according to the determined target power value 261. Optionally, the power P of the fuel cell system 205 is continuously checked 345, and in particular, whether the power P reaches the target power value 261.

[0087] Once the target power level 261 is reached, the switching sequence can be executed. For this purpose, the switching signal 258 is output, and switching 256 occurs.

[0088] After completion of the switching 256, the power P of the fuel cell system 205 is returned to a normal power value 266 by outputting the second power signal 265 to the fuel cell system 205. The normal power value 266 defines a power P of the fuel cell system 205 that is necessary and / or sufficient for normal operation.

[0089] If the shift 256 is safety-relevant, i.e., if the shift 256 has a safety relevance 280 that is required, for example, due to overspeed and / or downhill driving with engine braking or regenerative braking, this is defined, for example, with the shift request 257 and / or the shift recommendation 259, and this information or the safety indicator 281 is used to determine 320 the target power variable 261. The target power variable 261 is then calculated for a safety shift, in which, for example, higher power gradients can be used to perform the shift 256 as quickly as possible. The determined target power variable 261 can optionally be used directly for the shift decision 275, optionally omitting consideration of the shift options 270. The operational features 292 can then be implemented as described above.

[0090] The method 300 may be implemented by a computer program and / or computer-readable medium 400 (see Fig. 5) readably stored commands can be executed. The method 300 can be executed as soon as the switching recommendation 259 changes and / or a switching request 257 is detected. The method 300 can be interrupted at any process step as soon as a safety-relevant switching operation 256 needs to be performed.

[0091] Fig. 5 shows a schematic representation of a computer program and / or computer-readable medium 400 according to one aspect of the disclosure. The computer program and / or computer-readable medium 400 includes instructions (not shown) which, when the program or instructions are executed by a control unit 222, cause the control unit 222 to execute the method 300 and / or the steps of the method 300 according to Fig. 3 to be carried out.

[0092] The commands can be present as program code in any code or in any language, in particular in a code suitable for controlling and / or monitoring vehicles 200a, in particular commercial vehicles 200b. The computer program and / or computer-readable medium 400 can be or comprise any digital data storage device, such as a USB stick, a hard disk, a CD-ROM, an SD card, or an SSD card. The computer program does not necessarily have to be stored on such a computer-readable storage medium, but can also be accessible via the Internet or otherwise. Reference symbol (part of the description) 200a vehicle 200b commercial vehicle 205 Fuel cell system 210 Vehicle network; high-voltage network 215 braking resistor 222 control unit 230 Energy storage device 250 electric drive 251 Current status 252 power stroke 255 gearboxes 256 Switch 257 Switching request 258 switching signal 259 Gearshift recommendation 260 Power adjustment signal 261 Target performance 265 second power adjustment signal 266 Normal power size 270 options 271 efficiency and / or comfort-optimized switching option 272 switching point optimized switching option 275 Switching decision 280 Security relevance 281 Safety indicator 291 strategic features 292 operational characteristics 300 procedures 310 Recording a switching request 320 Determining a target performance value 330 Outputting a power adjustment signal 335 Checking the power adjustment signal 336 Checking the switching request 345 Checking Performance 350 Outputting a switching signal 360 Outputting a second power adjustment signal 400 Computer program and / or computer-readable medium P Performance t1 first target time t2 second target time QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2013 222 972 A1

[0016] DE 10 2011 018 182 A1

[0017] CN 113859053 A

[0017]

Claims

[1] Method (300) for shifting (256) a transmission (255) of an electrically driven vehicle (200a) having a fuel cell system (205), in particular a commercial vehicle (200b), the method (300) comprising: - detecting (310) a shift request (257) for shifting (256) the transmission (255); - determining (320) a target power variable (261) characterizing a power (P) of the fuel cell system (205) during switching (256); and - Outputting (330) a power adjustment signal (260) for adjusting the power of the fuel cell system (205) to the target power value (261) during the switching (256). [2] The method (300) of claim 1, wherein - the shift request (257) has a first target time (t1) for shifting (256) the transmission (255), and - the power adjustment signal (260) is output such that the target power variable (261) is set at the first target time (t1) and / or at a second target time (t2) different from the first target time (t1). [3] The method (300) of claim 2, wherein the method (300) comprises: - Checking (335) based on the first target time (t1), the power adjustment signal (260) and / or the second target time (t2). [4] Method (300) according to one of the preceding claims, wherein the target performance quantity (261) is determined according to one of several options (270). [5] Method (300) according to claim 4, wherein the plurality of options (270) comprise an efficiency and / or comfort-optimized switching option (271) and / or a switching time-optimized switching option (272). [6] Method (300) according to one of the preceding claims, wherein the target power variable (261) is determined such that an electric drive (250) of the vehicle (200a), in particular commercial vehicle (200b), provides a power stroke (252) which is increased compared to an actual state (251) during the switching (256). [7] Method (300) according to one of the preceding claims, wherein the method (300) comprises: - Checking (336) the switching request (257) taking into account the target power value (261). [8] Method (300) according to one of the preceding claims, wherein the method (300) comprises: - Checking (345) the power (P) of the fuel cell system (205). [9] Method (300) according to one of the preceding claims, wherein the method (300) comprises: - Outputting (350) a switching signal (258) for switching (256) the transmission (255). [10] Method (300) according to one of the preceding claims, wherein the method (300) comprises: - Outputting (360) a second power adjustment signal (265) for adjusting the power (P) of the fuel cell system (205) to a normal power value (266) after switching (256). [11] Method (300) according to one of the preceding claims, wherein - the switching request (257) comprises a safety indicator (281) indicating a safety relevance (280) of the switching (256), and - the determination (320) of the target power variable (261) and / or the output (330) of the power adjustment signal (260) takes place taking into account the safety indicator (281). [12] Computer program and / or computer-readable medium (400), comprising instructions which, when the program or instructions are executed by a control device (222), cause the control device (222) to carry out the method (300) and / or the steps of the method (300) according to one of the preceding claims. [13] Control unit (222) for an electrically driven vehicle (200a), in particular a commercial vehicle (200b), having a transmission (255) and a fuel cell system (205), wherein the control unit (222) is configured to carry out the method (300) according to one of claims 1 to 11. [14] Vehicle (200a), in particular commercial vehicle (200b), comprising a fuel cell system (205), an electric drive (250) with a transmission (255) and a control unit (222) according to claim 13.

Images