Method and data processing device for operating a hybrid electric vehicle
By receiving route information, estimating power demand, and defining reference trajectories and control points, the energy management challenges of hybrid electric vehicles are solved, enabling efficient energy use and load transfer, and improving operational efficiency and passenger comfort.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- VOLVO CAR CORP
- Filing Date
- 2022-10-27
- Publication Date
- 2026-05-19
AI Technical Summary
Hybrid electric vehicles face a trade-off between high precision and limited computing power and memory in energy management, and the limited capacity of energy storage devices makes it impossible to rely solely on electric traction.
By receiving route information, estimating power demand, allocating energy to energy storage devices, defining reference trajectories and control points, and using closed-loop control methods to efficiently manage load transfer between internal combustion engines and electric traction machines, and combining vehicle models to calculate power demand, efficient energy management is achieved.
It improves the operating efficiency of hybrid electric vehicles, reduces computing and storage requirements, ensures efficient energy use, and enhances overall efficiency and passenger comfort.
Smart Images
Figure CN116118703B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a method of operating a hybrid electric vehicle having an electric traction motor and an internal combustion engine electrically coupled to an energy storage device.
[0002] Furthermore, this disclosure relates to a data processing apparatus, including means for performing the above-described method. Background Technology
[0003] In this article, a hybrid electric vehicle (HEV) can be a plug-in hybrid electric vehicle (PHEV) or a non-plug-in hybrid electric vehicle.
[0004] As is well known, the efficiency of hybrid electric vehicles depends on their energy management, namely, how the internal combustion engine and electric traction motor are used. Electric traction motors typically operate more efficiently than internal combustion engines. However, due to the limited capacity of energy storage devices, it is impossible to rely solely on electric traction motors. Another challenge is that the vehicle's control unit has limited computing power and memory.
[0005] Therefore, in order to operate hybrid electric vehicles, a trade-off must always be sought between the high precision of the control method and the applicability of limited computational performance. Summary of the Invention
[0006] The subject matter of the independent claims of this disclosure at least partially addresses or alleviates this problem, and further examples are included in the dependent claims.
[0007] According to a first aspect, a method is provided for operating a hybrid electric vehicle having an electric traction motor and an internal combustion engine, the electric traction motor being electrically coupled to an energy storage device, the method comprising:
[0008] Receive route information in the form of multiple parameter sets, each parameter set being associated with a segment of the route and including parameters describing the average speed and parameters describing the average road gradient or elevation difference on the segment.
[0009] Estimate the power demand for each section of the road.
[0010] Distributing a portion of the energy stored in the energy storage device to at least one road segment in at least one manner, and / or distributing the amount of energy to be transferred to the energy storage device to at least one road segment in at least one manner.
[0011] Derive at least one reference trajectory, which describes the energy state of the energy storage device along the route, and the reference trajectory is derived by allocating a portion of the amount of energy stored in the energy storage device and / or allocating the amount of energy to be transferred to the energy storage device.
[0012] Define multiple control points on at least one reference trajectory, and
[0013] The operation of the hybrid electric vehicle is controlled based on the slope between the current energy state on at least one reference trajectory and the upcoming control point.
[0014] In this context, the slope is defined as the difference between the current state of energy of the energy storage device and its state of energy at the upcoming control point, divided by the route distance between the current location and the upcoming control point. It should also be understood that, in this context, the operation of the hybrid electric vehicle is controlled using closed-loop control. Furthermore, the control is performed in real time, meaning the control response is ensured within a specified time limit. Additionally, this method can be used in conjunction with hybrid electric vehicles having more than one electric traction machine (e.g., two electric traction machines).
[0015] In order to calculate the trajectory, it is clear that the initial level of the energy state of the receiving energy storage device is required.
[0016] Having route information in the form of a set of parameters associated with the segments of the route is computationally efficient. For example, each segment on the route can be indexed by specifying the starting point of a segment along the route or by storing the identifiers of adjacent segments. It is also possible to adapt the route information to different levels of computational performance by adjusting the length of the segments accordingly.
[0017] Therefore, the calculation of control points is highly efficient in terms of computing power and memory usage.
[0018] Because this method uses upcoming control points to calculate the slope and execute control of the hybrid electric vehicle, it utilizes predicted information about the route and the energy state of the energy storage devices. This results in the following: the method is capable of providing high efficiency for hybrid electric vehicles, i.e., the method is high-performance. Simultaneously, the method is computationally efficient, requiring only limited computational power and memory.
[0019] The output of this method can be a request or threshold from the electric traction machine's controller to the electric traction machine to start operation as an electric motor, start operation as a generator, or stop operation. Additional or alternative outputs of this method can be requests or thresholds from the internal combustion engine's controller to start or stop operation. In other words, this method controls the load transfer between the electric traction machine and the internal combustion engine.
[0020] In one example, the number of parameter sets is reduced because at least some of the multiple parameter sets are combined into a corresponding aggregate parameter set. In other words, the number of received road segments is reduced. Thus, the method can be performed with very low computational power and memory capacity. For example, reducing the number of parameter sets may include calculating the average aggregate parameters over multiple road segments (e.g., two road segments). The reduction in the number of parameter sets and corresponding road segments can be specified as data preprocessing.
[0021] Vehicle models can be used to estimate electricity demand. A vehicle model can include values characterizing vehicle mass and a set of parameters that define road load based on road gradient, average speed, and corresponding distance. In other words, using a vehicle model, the amount of electricity required to travel along a road segment can be calculated. This is computationally efficient. Furthermore, if the size of the road segment is chosen appropriately, this method is highly accurate.
[0022] In one example, energy stored in energy storage devices is allocated to road segments starting with those having low power demand. This can be achieved by categorizing these segments according to their respective power demands. The available energy in the storage devices is then allocated to segments starting with those having the lowest power demand. Energy allocation ceases if the remaining energy level is zero or below a predetermined threshold. Therefore, the available energy in the storage devices is utilized to a high degree. Furthermore, the method of allocating energy to road segments is straightforward. Of course, this energy allocation is only necessary when the total energy demand of a road segment exceeds the available energy in the storage devices. Otherwise, vehicles could travel along the route using only electric traction.
[0023] Energy stored in energy storage devices can be allocated to road segments so that the available energy in the devices is substantially fully utilized by the time the route ends, deriving a corresponding first reference trajectory. Note that the term "first" is used for simplification only and does not imply the number of trajectories. This first reference trajectory can be designated as a depletion trajectory because the goal is to use substantially all the available energy in the energy storage devices. In this context, full or complete utilization of available energy means the energy storage devices are emptied. Technically, this means the energy storage devices are depleted until a lower energy state threshold is reached. In this scenario, the internal combustion engine is used as little as possible. Therefore, hybrid electric vehicles operate with high efficiency. The first reference trajectory can be particularly used for plug-in hybrid vehicles with fully or partially charged energy storage devices at the start of the drive cycle.
[0024] It should be noted that this method also takes into account the transfer of energy to the energy storage device while traveling along the route. If the electric traction motor operates as a generator, energy can be transferred to the energy storage device. In this case, the electric traction motor can be powered by the inertial motion of the vehicle or by an electric internal combustion engine. Alternatively, in the case of a PHEV, the energy storage device can receive additional energy from the grid. Since any kind of charging will change the current energy state of the energy storage device, this will at least affect the slope calculated as a step in the method according to this disclosure.
[0025] Energy stored in or planned to be stored in an energy storage device can be allocated to a road segment such that at the end of the route, a predetermined energy level remains in the energy storage device, deriving a corresponding second reference trajectory. As previously stated, the term "second" is used for simplification only and does not imply the number of trajectories. The predetermined energy level may correspond to a fully charged state or a predetermined partially charged state of the energy storage device. The second reference trajectory can be designated as a charge sustaining trajectory. The second reference trajectory may be particularly useful for non-plug-in hybrid electric vehicles because it results in at least a certain amount of energy being available from the energy storage device for potentially upcoming low-speed or low-electric-drive segments. Furthermore, the second reference trajectory can be applied if the energy storage device is empty or the energy state is below a predetermined threshold at the start of a drive cycle. The calculation of the second reference trajectory is also computationally efficient. As already explained, when calculating the second reference trajectory, the transfer of energy to the energy storage device during driving is, of course, taken into account.
[0026] If the current state of energy is below a maintenance threshold, a second reference trajectory can be used to control the hybrid electric vehicle. In short, this means the current state of energy is below a specific predetermined state of energy. Since the second reference trajectory results in the desired state of charge at the end of the drive cycle (i.e., at the end of the route), this is a simple and reliable way to efficiently operate the electric vehicle.
[0027] The second reference trajectory can be calculated, for example, by designating segments with electricity demand below a specific and relatively low level as depletion segments, i.e., allocating the energy stored in the energy storage device to these segments. The second trajectory can then be constructed by summing all the energy in the depletion segments, i.e., starting from the end of the route (i.e., at the expected final energy level of the energy storage device) and reversing back to the first segment.
[0028] In one example, control points on different reference trajectories are used to control the hybrid electric vehicle. This means that the method can switch between reference trajectories used to control the operation of the hybrid electric vehicle, depending on the conditions while traveling along the route. Therefore, the method can adjust according to the situation during driving. This makes the operation of the hybrid electric vehicle both efficient and reliable.
[0029] This method can be periodically executed, taking into account the remaining route segments. In other words, it is executed using a retreating horizon. This results in the storage device reaching its desired state of energy with high reliability at the end of the path. Simultaneously, the hybrid electric vehicle operates efficiently.
[0030] If the slope is positive, it increases the engine's on / off threshold. A positive slope means that the energy state at the upcoming control point is lower than the current state of charge. Therefore, it is necessary to encourage the discharge of energy storage devices. This is because the engine's on / off threshold (e.g., in terms of electrical demand) increases. In a simplified way, this means that during driving, the engine starts later and shuts off earlier, increasing the portion of driving that is not using the internal combustion engine.
[0031] If the slope is negative or zero, the engine's on / off threshold is lowered. A negative slope means the current energy state is lower than the energy state at the upcoming control point. If the slope is zero, the current energy state is essentially equal to the energy state at the upcoming control point. In both cases, charging of energy storage devices is encouraged, i.e., the use of the internal combustion engine is encouraged. For this purpose, the corresponding on / off threshold is lowered, for example, in terms of electricity demand. In short, this means that during driving, the engine starts earlier and shuts off later, resulting in an increased portion of the road segment where the internal combustion engine is used.
[0032] In another example, a charging threshold for the slope is defined, and if the slope falls below the charging threshold, the internal combustion engine is used to charge the energy storage device. The charging threshold is negative. This allows for highly reliable achievement of the energy storage device's desired energy state.
[0033] In addition, the engine on / off threshold can also be set as a function of vehicle speed.
[0034] When the requested speed is below a low-speed threshold, the hybrid electric vehicle can be driven solely by the electric traction motor. When the hybrid electric vehicle is traveling at low speeds, the noise, vibration, and harshness (NVH) generated by the internal combustion engine are significantly more pronounced than wheel and wind noise. The electric traction motor produces significantly less noise compared to the internal combustion engine. This improves auditory comfort for passengers, and also for those around the hybrid electric vehicle.
[0035] If the current state of energy is sufficient to reach the end of the route, the hybrid electric vehicle can be driven solely by the electric traction motor. Since the electric traction motor offers higher operating efficiency than the internal combustion engine, this improves the overall efficiency of the hybrid electric vehicle.
[0036] The method according to this disclosure can be implemented at least in part by a computer, and can be implemented in software or hardware, or in both software and hardware. Furthermore, the method can be executed by computer program instructions running on a device providing data processing functionality. The data processing device can be a suitable computing device, such as an electronic control module, or a distributed computer system. The data processing device or computer can each include one or more of a processor, memory, data interface, etc.
[0037] According to a second aspect, a data processing apparatus is provided, including means for performing the method according to the present disclosure. This data processing apparatus allows for the efficient operation of hybrid electric vehicles. Furthermore, it is computationally efficient.
[0038] It should be noted that the examples above can be combined with each other, regardless of the aspects involved. Therefore, this method can be combined with features of a data processing device, and similarly, the data processing device can be combined with the features described above regarding this method.
[0039] These and other aspects of this disclosure will become apparent from the examples described below, and will be illustrated with reference to the examples described below. Attached Figure Description
[0040] Examples of this disclosure will be described below with reference to the accompanying drawings.
[0041] Figure 1 The method according to this disclosure is shown.
[0042] Figure 2 It shows the result of Figure 1 An exemplary first reference trajectory calculated by the method,
[0043] Figure 3 It shows the result of Figure 1 An exemplary second reference trajectory calculated by the method, and
[0044] Figure 4 A data processing apparatus according to this disclosure is shown, including one for performing... Figure 1 The apparatus for the method.
[0045] The accompanying drawings are merely schematic representations and are intended to illustrate this disclosure only. In principle, identical or equivalent elements have the same reference numerals. Detailed Implementation
[0046] Figure 1 A method for operating a hybrid electric vehicle is shown, the hybrid electric vehicle having an electric traction motor and an internal combustion engine, the electric traction motor being electrically coupled to an energy storage device.
[0047] In the first step S1, the method receives route information in the form of multiple (N) parameter sets, each parameter set being associated with a segment of the route.
[0048] The N parameter sets can be provided by the navigation unit.
[0049] In this example, each parameter set includes a parameter describing the average speed and a parameter describing the average road gradient on the corresponding road segment. The average speed can be derived from speed limits stored as part of the map data used as navigation units.
[0050] Of course, each segment of the route is indexed so that the location of each segment along the route is known.
[0051] In the second step S2, the number N of parameter sets is reduced. In this example, the number N is reduced by 50% because the pairs of parameter sets describing adjacent route segments are combined into corresponding aggregate parameter sets. This means that for each pair, the aggregate average speed is calculated using the corresponding average speed of the parameter sets forming the pair, and the aggregate average road slope is calculated using the corresponding average road slope of the parameter sets forming the pair. The calculation of the aggregate parameter sets can be weighted by the distance covered by the corresponding road segments. Of course, if the road segments cover the same distance, the parameter sets to be aggregated are weighted equally. Therefore, in this example, the number of parameter sets is N / 2.
[0052] Subsequently, in the third step S3, the power demand for each road segment is estimated. In this context, the power demand can be positive if the hybrid electric vehicle needs to apply electricity to the road, at least theoretically. The power demand can be negative if the hybrid electric vehicle receives electricity (e.g., because it should be traveling along a very steep road segment).
[0053] To estimate electricity demand, a vehicle model was used, which will be explained in detail below.
[0054] Subsequently, in the fourth step S4, a portion of the energy stored in the energy storage device is allocated to the selection of road segments. Simultaneously, if applicable, the amount of energy to be transferred to the energy storage device is allocated to the road segments where the energy storage device is to be charged.
[0055] To this end, road segments are categorized according to their electricity demand, and the energy stored in energy storage devices is allocated to segments starting with those having the lowest electricity demand, until virtually all the energy stored in the devices is used. In detail, this means using the energy stored in the devices until the energy state reaches a predetermined threshold.
[0056] Then, in the fifth step S5, a first reference trajectory T1 describing the energy state of the energy storage device on the route is derived from this energy allocation. Figure 2 An example is shown. The first reference trajectory T1 is the so-called depletion trajectory because virtually all the energy available in the energy storage device has been used when the end of the route is reached.
[0057] In order to effectively control the operation of the hybrid electric vehicle, multiple control points are defined on the first reference trajectory (sixth step S6).
[0058] exist Figure 2 In the example, seven control points D1 to D7 are defined, where control point D7 represents the energy state at the end of the route.
[0059] In this example, in the fourth step S4, the energy stored in the energy storage device can also be distributed to the route segment in another way.
[0060] Now, the energy stored in or planned to be stored in energy storage devices is allocated to road segments so that at the end of the route, a predetermined level of energy remains in the energy storage devices.
[0061] Then, in step S5, the corresponding second reference trajectory T2 is derived. This second reference trajectory T2 describes the reference energy state of the energy storage device along the route. The second reference trajectory T2 is as follows: Figure 3 As shown. This second reference trajectory is the so-called sustaining trajectory.
[0062] Furthermore, seven control points C1 to C7 are defined, where control point C7 represents the energy state at the end of the route.
[0063] In this context, the first reference trajectory T1 is calculated from the energy state of the energy storage device at the start of the drive cycle. The available energy is then allocated to the road segment starting with the segment requiring the lowest power, such that the energy stored in the energy storage device is substantially fully utilized by the end of the drive cycle. In technical terms, this means reaching a low energy level at the end of the drive cycle.
[0064] The calculation of the second reference trajectory T2 is independent of the energy state of the energy storage device at the start of the drive cycle. The calculation begins at the end of the route and the desired energy state at that point. Then, the second reference trajectory T2 is recursively calculated by working backward from the end of the route to the beginning. The change in the energy state distribution for each segment is defined based on the segment's power demand.
[0065] Subsequently, in the seventh step S7, closed-loop control of the operation of the hybrid electric vehicle is performed based on the slope between the current energy state and the energy state of the upcoming control point on the first reference trajectory T1 or the second reference trajectory T2.
[0066] exist Figure 2 The diagram illustrates an exemplary current energy state E1 at an exemplary location P1 within the route. It also shows the slope SL1 between the current energy state and the energy state of the upcoming control point D4. This slope is calculated by dividing the difference ΔE between the current energy state E1 and the energy state at control point D4 by the route distance ΔP between the current location P1 and the location of control point D4 along the route.
[0067] Also in Figure 3 The diagram illustrates an exemplary current energy state E2 at an exemplary location P2 within the route. It also shows the slope SL2 between the current energy state and the energy state of the upcoming control point C4. This slope is calculated by dividing the difference ΔE' between the current energy state E2 and the energy state at control point C4 by the route distance ΔP' between the current location P2 and the location of control point C4 along the route.
[0068] When traveling along the route, both reference trajectories T1 and T2 can be used, as will be explained below.
[0069] In this example, if the current energy state is below a predefined maintenance threshold, then the second trajectory T2 (see...) Figure 3 This is used to control hybrid electric vehicles. In short, this means that if the state of energy is below a minimum acceptable level, the second reference trajectory T2 is used. Otherwise, the first reference trajectory T1 is used. This means that if the state of energy is above the minimum acceptable level, the intention is to use the electric traction motor as much as possible, and therefore utilize the energy stored in the energy storage devices.
[0070] For two reference trajectories T1 and T2, if the slope is positive, i.e., if the current energy state is higher than the energy state of the upcoming control point, the engine on / off threshold increases. This implies an encouragement of the use of electric traction machines.
[0071] If the slope is negative or zero, the engine's on / off threshold is reduced. This means that if the current energy state is equal to or lower than the energy state of the upcoming control point, the use of the internal combustion engine is encouraged.
[0072] In both cases, the on / off threshold can be a power demand level. The on / off threshold is further set as a function of vehicle speed.
[0073] If, during the execution of this method, it is found that the current energy state is sufficient to reach the end of the route, the hybrid electric vehicle is driven solely by the electric traction unit, i.e., the internal combustion engine is shut down, and the electric traction unit operates as either an electric motor or a generator depending on the specific circumstances.
[0074] In addition, if the requested driving speed is below the low speed threshold, the hybrid electric vehicle can be driven solely by the electric traction motor.
[0075] The above method is performed periodically, always taking into account the remaining sections of the route. Therefore, the reference trajectories T1, T2 and control points C1-C7, D1-D7 are periodically recalculated to ensure that the desired energy state is reached at the end of the route with high reliability.
[0076] Figure 4 The data processing device 10 is shown, including means for performing the above-described method.
[0077] More specifically, the data processing device 10 has a first input interface 12 for receiving route information in the form of multiple parameter sets, as described in step S1. For this purpose, the first input interface 12 is configured to connect to the navigation unit.
[0078] The second input interface 14 is configured to receive the energy status of the energy storage device. The second input interface 14 is configured to connect to the controller of the energy storage device.
[0079] Furthermore, the first output interface 16 is configured to send operating requests, such as on / off requests or on / off thresholds, to the controller of the electric traction machine. It can also send charging requests to the electric traction machine, indicating the desired charging power of the energy storage device. In this case, the electric traction machine needs to operate as a generator. If no charging request is requested, the request value will be zero.
[0080] The second output interface 18 is configured to send on / off thresholds to the controller of the internal combustion engine.
[0081] In addition, the data processing device 10 includes a processor 20 and a memory 22, configured to perform the above-described methods.
[0082] For this purpose, a vehicle model 24 is also provided on memory 22. Vehicle model 24 includes values characterizing vehicle mass and a lookup table that includes parameters defining road load based on road gradient, average speed, and corresponding distance. Optionally, these parameters can be estimated using other data processing devices for the vehicle.
[0083] Those skilled in the art, in practicing the claimed disclosure, can understand and implement other variations of the disclosed examples by studying the accompanying drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. A single processor or other unit can perform the functions of several items or steps listed in the claims. The fact that certain measures are listed in mutually different dependent claims does not mean that a combination of these measures cannot be used advantageously. Computer programs can be stored / distributed on suitable media, such as optical storage media or solid-state media provided or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0084] Reference Symbol List
[0085] 10 Data processing equipment
[0086] 12 First Input Interface
[0087] 14 Second Input Interface
[0088] 16 First Output Interface
[0089] 18 Second Output Interface
[0090] 20 processors
[0091] 22 Memory
[0092] 24 vehicle models
[0093] C1-C7 control points
[0094] Control points D1-D7
[0095] E1 Current Energy Status
[0096] E2 Current Energy Status
[0097] ΔE is the difference between the current energy state and the energy state at the upcoming control point.
[0098] ΔE' is the difference between the current energy state and the energy state of the upcoming control point.
[0099] P1 Current position
[0100] P2 Current position
[0101] ΔP is the distance along the route.
[0102] ΔP' Distance along the route
[0103] S1 First Step
[0104] S2 Second Step
[0105] S3 Third Step
[0106] S4 Fourth Step
[0107] S5 Fifth Step
[0108] S6 Sixth Step
[0109] S7 Step Seven
[0110] SL1 slope
[0111] SL2 slope
[0112] T1 First Reference Trajectory
[0113] T2 Second Reference Trajectory
Claims
1. A method for operating a hybrid electric vehicle, the hybrid electric vehicle having an electric traction motor and an internal combustion engine, the electric traction motor being electrically coupled to an energy storage device, the method comprising: Receive route information in the form of multiple parameter sets, each parameter set being associated with a segment of the route and including parameters describing the average speed and parameters describing the average road gradient or elevation difference on the segment (S1). Estimate the power demand for each road segment (S3). Distribute a portion of the amount of energy stored in the energy storage device to at least one of the road segments in at least one manner, and / or distribute the amount of energy to be transmitted to the energy storage device to at least one of the road segments in at least one manner (S4). Export at least one reference trajectory (T1; (T2), the at least one reference trajectory describes the reference energy state of the energy storage device on the route, the reference trajectory is obtained by allocating a portion of the amount of energy stored in the energy storage device and / or allocating the amount of energy to be transferred to the energy storage device (S5). Define multiple control points (D1-D7; C1-C7) (S6) on the at least one reference trajectory (T1; T2), and The operation of the hybrid electric vehicle is controlled based on the slope (SL1; SL2), wherein the slope (SL1; SL2) is defined as: the difference between the current energy state on the at least one reference trajectory (T1; T2) and the reference energy state at the upcoming control point (D1-D7; C1-C7), divided by the route distance (S7) between the current position and the upcoming control point (D1-D7; C1-C7).
2. The method according to claim 1, wherein, Since at least some of the multiple parameter sets are combined into a corresponding aggregate parameter set, the number of parameter sets is reduced (S2).
3. The method according to claim 1 or 2, wherein, The vehicle model (24) is used to estimate the power demand.
4. The method according to claim 1 or 2, wherein, The energy stored in the energy storage device is distributed to road sections starting from those with low power demand.
5. The method according to claim 1 or 2, wherein, The energy stored in the energy storage device is distributed to the road segment such that when the end of the route is reached, the available energy in the energy storage device is substantially fully utilized, and a corresponding first reference trajectory (T1) is derived.
6. The method according to claim 1 or 2, wherein, The energy stored in the energy storage device or the energy planned to be stored in the energy storage device is allocated to the road segment, such that at the end of the route, a predetermined energy level remains in the energy storage device, and a corresponding second reference trajectory (T2) is derived.
7. The method according to claim 6, wherein, If the current energy state is below the maintenance threshold, the second reference trajectory (T2) is used to control the hybrid electric vehicle.
8. The method according to claim 6, wherein, Control points (D1-D7; C1-C7) on different reference trajectories (T1; T2) are used to control the hybrid electric vehicle.
9. The method according to claim 1 or 2, wherein, The method is performed periodically, taking into account the remaining sections of the route.
10. The method according to claim 1, wherein, If the slope (SL1; SL2) is positive, the engine on / off threshold increases.
11. The method according to claim 1, wherein, If the slope (SL1; SL2) is negative or zero, the engine's on / off threshold is reduced.
12. The method according to claim 10 or 11, wherein, The on / off threshold is set as a function of the vehicle speed.
13. The method according to claim 1 or 2, wherein, If the requested driving speed is below the low speed threshold, the hybrid electric vehicle is driven solely by the electric traction machine.
14. The method according to claim 1 or 2, wherein, If the current energy state is sufficient to reach the end of the route, the hybrid electric vehicle is driven solely by the electric traction motor.
15. A data processing apparatus (10) comprising means for performing the method of claim 1 or 2.