Method for shifting in drive of vehicle

Abstract

The invention relates to a method for shifting a gear in a drive (2) of a vehicle, the drive having an electric machine (4) and a power shift transmission (6), the power shift transmission having a drive shaft (10) connected to an output shaft (11) of the electric machine and an output shaft (12) connected to a chassis (8) in order to move the vehicle, wherein the power shift transmission has at least two gears having different transmission ratios (i1, i2), a transmission branch (20, 22) having a clutch (K1, K2) is provided for each of the gears, said clutch being designed to cause a force-fitting connection of the drive shaft to the output shaft in the closed state, if one of the gears is engaged, the torque between the drive shaft and the driven shaft is transmitted only via one of the transmission branches, and the electric machine can be adjusted in a rotational speed adjustment mode according to a target rotational speed. Wherein the method comprises a step of carrying out a load change phase (P2) and a synchronization phase (P3) in a rotational speed control mode when shifting from the engaged old gear to a new gear to be engaged.

Description

Technical Field

[0001] The invention relates to a method for shifting gears in a drive device of a vehicle, as well as to a computing unit, a drive device and a computer program for carrying out the method. Background Art

[0002] Power-shift clutches have already gained acceptance in mobile drive technology. Various solutions for monitoring the traction force during the gearshift process are found in different fields of application. Dual-clutch transmissions and continuously variable transmissions, such as so-called CVTs (continuously variable transmissions), are known from the passenger car sector. Mobile driven machines can have a power-shift transmission with multiple multi-disc clutches, which carry out the gearshift without traction force disturbances or only with reduced traction force disturbances. During a gearshift, both clutches (old gear and new gear) are engaged simultaneously during this period. Summary of the invention

[0003] According to the invention, a method for shifting gears in a drive of a vehicle, a computing unit, a drive and a computer program for implementing the method are proposed, having the features of the independent claims. Advantageous embodiments are the subject matter of the dependent claims and the following description.

[0004] The invention uses measures for implementing a load change between power paths determined by different gears during a load change phase in a speed control mode of the electric machine, as well as for implementing a speed synchronization (or synchronization) during a synchronization phase. The speed control makes it possible to control the speed of the vehicle in an advantageous manner during the gearshift process by presetting a corresponding target speed for the electric machine. During the control in the speed control mode, the reliable continuous power of the electric machine can be exceeded briefly, so that the gearshift shock is minimized.

[0005] In particular, the method comprises the step of carrying out a load change phase and a synchronization phase in a speed-controlled mode when shifting from an old, engaged gear to a new gear to be engaged.

[0006] The drive device has a motor and a power shift transmission. The power shift transmission has a drive shaft connected to the output shaft of the motor and a driven shaft connected to the vehicle's travel mechanism. In short, the vehicle can be moved by the drive device. The vehicle is preferably a movable work machine, but is not limited thereto.

[0007] A powershift transmission has at least two gears with different transmission ratios, wherein a transmission branch with a clutch is provided for each gear, which in the closed state brings about a friction-locking connection of the drive shaft to the output shaft (via the transmission branch in which the corresponding clutch is arranged), so that a torque can be transmitted via the corresponding transmission branch. The clutch can be, for example, a friction clutch or a multi-plate clutch. Depending on how much the friction partners (lamellae) of the clutch are pressed together (by an actuator and / or hydraulically), the maximum torque that can be transmitted via the clutch is determined, which can be greater or less.

[0008] The electric machine can be controlled or regulated with a target speed in a speed control mode. The control or regulation can be performed by a control device included in the electric machine and / or by a control device of the drive device. "One of the gears is engaged" can be understood in such a way that the torque between the drive shaft and the driven shaft is transmitted only via a single transmission branch of the transmission branches. Thus, one of the clutches is completely closed and the other clutch is completely open (no torque transmission occurs).

[0009] The target speed of the speed control mode of the electric machine is preferably changed in the synchronization phase, wherein at the end of the synchronization phase the target speed is determined from the speed of the output shaft taking into account the transmission ratio of the new gear. The expression "the target speed is determined from the speed of the output shaft taking into account the transmission ratio of the new gear" used here and below means that if i represents the corresponding transmission ratio, then the target speed ω soll As the speed of the driven shaft ω aus Calculated by multiplying the transmission ratio i:

[0010] ω soll =ω ous ·i

[0011] Therefore, ω applies here soll =ω ous ·i neu , where i neu is the transmission ratio of the new gear.

[0012] Preferably, during the load change phase, the clutch of the transmission branch corresponding to the old gear is disconnected or opened, and the clutch of the transmission branch corresponding to the new gear is connected or closed. Further preferably, the method is implemented (in particular the clutch is controlled in such a way that during the load change phase, if the gear shift is a traction upshift or a coasting downshift, the disconnected clutch is engaged and the engaged clutch is slipping, and if the gear shift is a coasting upshift or a traction downshift, the disconnected clutch is slipping and the engaged clutch is engaged. This allows the vehicle speed to be directly controlled via the target speed of the electric machine.

[0013] "Traction operation" means that the electric machine functions as a motor, that is, electrical energy is converted into kinetic energy. "Coasting operation" means that the electric machine functions as a generator, that is, kinetic energy is converted into electrical energy. "Upshift" means that the ratio of the speed of the driven shaft to the speed of the drive shaft is greater after the gear shift process than before the gear shift. "Downshift" means that the ratio of the speed of the driven shaft to the speed of the drive shaft is smaller after the gear shift than before the gear shift. The terms "traction upshift", "traction downshift", "coasting upshift" and "coasting downshift" represent corresponding combinations of traction operation or coasting operation with upshift or downshift.

[0014] If the gearshift is a traction upshift or a coasting downshift, the load change phase is preferably carried out before the synchronization phase, and if the gearshift is a coasting upshift or a traction downshift, the load change phase is preferably carried out before the synchronization phase. In this way, different torque transmission directions and different shifting directions in traction operation or coasting operation are taken into account.

[0015] Preferably, the electric motor can be controlled according to a preset torque and can be adjusted in a torque control mode, wherein, if one of the gears is engaged, the electric motor is adjusted in the torque control mode, wherein the method also includes the following steps: during a first transition phase, before implementing a load change phase and a synchronization phase, the adjustment of the electric motor is changed from a torque control mode to a speed control mode; and during a second transition phase, after implementing a load change phase and a synchronization phase, the adjustment of the electric motor is changed from a speed control mode to a torque control mode.

[0016] According to this embodiment, the electric machine has a torque control mode in addition to the speed control mode, which is implemented with a preset torque. If one of the gears is engaged, the electric machine is controlled in the torque control mode. Before the first shift phase and after the second shift phase, one of the gears is engaged in each case, so that in addition to the gear change, the electric machine is operated in the torque control mode.

[0017] When engaging a gear, a safety torque can be set, i.e. the maximum torque that can be transmitted by the closed clutch (by the safety torque) is greater than the torque actually transmitted. The following preferred embodiment of the method allows this safety torque to be eliminated when switching from a torque control mode to a speed control mode and to be built up when switching from a speed control mode to a torque control mode without the torque of the electric machine fluctuating drastically.

[0018] It is further preferred that the safety torque is eliminated during the first transition phase, wherein the torque setting during the first transition period is determined as the sum of the torque setting of the torque control mode at the start of the first transition period, which is weighted by a time-dependent factor that decreases from 1 to 0 within the scope of the first transition period, and the torque setting of the speed control mode. It is also further preferred that the torque setting of the speed control mode is determined during the first transition period based on a target speed of the electric machine, which is determined as the sum of the speed of the electric machine at the start of the transition period and a time-dependent transition summand determined from the rate of change of the speed of the output shaft taking into account the transmission ratio of the old gear.

[0019] It is also further preferred that the safety torque is built up during the second transition phase, wherein during the second transition period the preset torque is determined as the sum of the torque preset of the torque control mode at the start of the second transition period, which is weighted by a time-dependent factor that increases from 0 to 1 within the scope of the second transition period, and the torque preset of the speed control mode. It is also further preferred that during the second transition period the torque preset of the speed control mode is determined based on a target speed of the electric machine, wherein the target speed is determined as the sum of a starting summand and a time-dependent transition summand, wherein the starting summand is determined from the speed of the output shaft at the start of the transition period taking into account the transmission ratio of the new gear, and wherein the time-dependent transition summand is determined from the rate of change of the speed of the output shaft taking into account the transmission ratio of the new gear.

[0020] The computing unit according to the invention, for example a control device of a mobile driven machine, is configured, in particular in terms of programming, to carry out the method according to the invention.

[0021] It is also advantageous to implement the method according to the invention in the form of a computer program or computer program product with program codes for implementing all method steps, because this causes particularly low costs, especially if the control device for execution is also used for other tasks and therefore already exists. Finally, a machine-readable storage medium is provided, which has a computer program as described above stored thereon. Suitable storage media or data carriers for providing computer programs are in particular magnetic memories, optical memories and electrical memories, such as hard disks, flash disks, EEPROMs, DVDs, etc. It is also possible to download programs via a computer network (Internet, intranet, etc.). Such downloading can be done here in a wired or cabled or wireless manner (e.g., via a WLAN network, 3G-, 4G-, 5G- or 6G-connection, etc.).

[0022] Further advantages and embodiments of the invention are apparent from the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The invention is schematically illustrated in the drawings on the basis of exemplary embodiments and is described below with reference to the drawings.

[0024] Figure 1 The basic topology of a drive system of a vehicle is shown, in which the method according to the invention can be used.

[0025] Figure 2 The torque curve and the speed curve during the traction upshift are shown.

[0026] Figure 3 The case in which the setpoint torque for the electric machine is determined during the first transition phase is described.

[0027] Figure 4 The shift logics for different shift types of a dual-speed transmission are described. DETAILED DESCRIPTION

[0028] Figure 1 The basic topology of a drive 2 of a vehicle in which the method according to the invention can be implemented is shown. The drive 2 comprises an electric machine 4 which is connected to a chassis 8 of the vehicle via a powershift transmission 6 in order to move the vehicle.

[0029] The powershift transmission 6 has a drive shaft 10 connected to the output shaft 11 of the electric machine in a rotationally fixed manner and a driven shaft 12 connected to the chassis. The chassis 8 has, for example, a transmission, in particular a differential transmission, and a vehicle drive shaft, via which the rotational movement and torque of the driven shaft 12 are transmitted to wheels or chains or the like of the chassis in order to move the vehicle (not shown in detail). The powershift transmission 6 shown has two different gears by way of example. In general, a powershift transmission can have more than two gears and corresponding transmission branches.

[0030] The electric machine 4 can be controlled with a preset torque. Furthermore, the electric machine 4 can be controlled, for example, by a control device (not shown in detail) of the electric machine 4 and / or the drive device 2 in a torque control mode and a speed control mode.

[0031] In the powershift transmission 6, the drive shaft 10 and the driven shaft 12 can be connected via two transmission branches 20, 22, which have different transmission ratios i1, i2. A first clutch K1 is provided in the first transmission branch 20 and a second clutch K2 is provided in the second transmission branch 20. By closing the clutches K1, K2, a non-positive connection is established between the drive shaft 10 and the driven shaft 12 via the corresponding transmission branches 20, 22. The non-positive connection is disconnected by opening the clutch.

[0032] The two transmission branches 20, 22 correspond to different gears. If one clutch is closed and the other clutch is open, that is to say a gear is engaged, the speed ω of the drive shaft 10 and the motor 4 is EM The same speed as the driven shaft speed ω aus The ratio between is generated by the corresponding transmission ratio. Thus, when the first clutch K1 is closed and the second clutch K2 is open (first gear or first transmission branch), ω applies. EM =i1·ω aus , and applies when the first clutch K2 is closed and the second clutch K1 is open (second gear or second transmission branch) EM =i2·ω aus The powershift transmission shown has two gears by way of example. In general, the invention can of course also be used in powershift transmissions having more than two gears.

[0033] If a gear is engaged, that is, if one clutch is closed and the other clutch is open, the electric machine 4 is controlled in torque mode. When changing gears, both clutches are temporarily engaged at the same time, that is, the torque is transmitted via both clutches or transmission branches, at least one of the clutches slipping. The open clutch is also called the cut-out clutch; the closed clutch is also called the engaged clutch. This process is described in the following Figure 2 In the explanation, the gear shift is explained by means of an exemplary gear change, namely a traction upshift. The old gear that is engaged is switched to the new gear that is to be engaged.

[0034] Furthermore, a control device 30 (computing unit) is shown, which can be considered as part of the drive device 2. This control device is used to control or regulate the electric machine 4 and to control the transmission 6, in particular the clutches K1, K2. In addition, the control device 30 can detect the measured values ​​of a speed sensor 32 that measures the speed of the drive shaft 10 or the output shaft 11 and / or the measured values ​​of a speed sensor 34 that measures the speed of the output shaft 12. The corresponding control lines or signal lines are shown as dashed lines. The control device 30 is particularly designed to implement the method according to the invention.

[0035] Figure 2 The torque curve and the speed curve during the traction upshift are shown. The figure includes two graphs, in which the transmission output torque M is plotted in the upper curve. aus (torque on the driven shaft 12), the clutch torque M Kalt (torque transmitted through the clutch of the old gear) and the engaged clutch torque M Kneu(torque transmitted by the clutch of the new gear) and the torque M of the motor is plotted in the lower curve EM and the motor speed ω EM In both diagrams, the corresponding curves are plotted over the time t, which is indicated here, for example, in seconds (s). The torque is indicated in the two diagrams by way of example in Newton meters (Nm) (scale on the left). The motor speed in the lower diagram is indicated by way of example in revolutions per minute (scale on the right).

[0036] The shifting process shown includes four phases, which are implemented in the order described during a traction upshift: a first transition phase P1 (0.0-0.2 s), a load change phase P2 (0.2-0.4 s), a synchronization phase P3 (0.4-0.6 s) and a second transition phase P4 (0.6-0.8 s).

[0037] In the first, preferably arranged, shifting phase P1, the safety torque M for preventing slip is eliminated during driving in the gear engaged immediately at the start of the shifting process. S , that is, the maximum transmittable torque of the closed, force-locking clutch is reduced to the torque actually transmitted. At the same time, the electric machine is switched from torque control mode to speed control mode. During the transition, the last torque preset M of the torque control before the start of the shifting process is set to MV Multiply by factor k(t) and add to speed control M DR In order to determine the preset torque M for the motor EM :

[0038] M MV k(t)+M DR =M EM

[0039] The sum of these during the first transition phase P1 forms Figure 3 The first transition phase extends within the range of the first transition time period from t0 to t1, wherein in the above formula, t0=0 is assumed as an example. S Established.

[0040] The factor k(t) can be chosen, for example, as

[0041] k(t)=1-(t-t0) 2 / (t1-t0) 2 ; t∈[t0,t1]

[0042] The speed control determines the speed control M based on the target speed for the electric machine. DR The target speed ω sollThe speed ω at the transmission output, that is, the output shaft 12 aus Speed ​​acceleration The current speed of the motor ω0 and the time t from the start t0 of the shifting process are calculated. Preferably, a linear variation curve is involved so that the acceleration remains constant. The calculation is performed, where ialt is the transmission ratio of the old gear, that is, the gear engaged at the beginning of the shifting process:

[0043]

[0044] The first summand of this formula forms the time-dependent transition summand. Overall, this approach avoids the motor torque M EM of disturbance.

[0045] During the load change phase P2, the transmission capacity of the engaged clutch is increased; that is, the engaged clutch torque M Kneu The friction partner, that is, the plates of the multi-disc clutch, are pressed together to an increased extent by means of an actuator and / or hydraulically. Due to the power flow in the friction clutch, the clutch torque M on the disengaged clutch is simultaneously reduced. Kalt It is important that the disconnected clutch no longer transmits torque (isolating) and no longer slips during the load change at the moment of full load acceptance of the engaged clutch. Since the disconnected clutch is continuously engaged, the electric machine readjusts the motor torque so that the speed acceleration in the drive train and the vehicle acceleration remain constant. Therefore, the speed for the target speed ω soll(t) The above formula continues to be valid. The preset torque M for the motor EM It is determined exclusively by speed control, ie in speed control mode.

[0046] The clutch torque is decisively influenced by the actuating mechanism during this phase. Kalt 、M Kneu The calculation of is performed online in the transmission control unit (TCU) and is based on the engine torque M EM , the transmission ratio i of the corresponding gear alt 、i neu and the corresponding shift factor S neu / alt (t)∈[0, 1]. The shift factor indicates whether the clutch is open or closed. Therefore, the clutch torque in load change is:

[0047] M Kalt =M EM ·i alt ·s alt

[0048] M Kneu =M EM ·i neu ·s neu

[0049] After the load change, the speed of the electric machine is synchronized in the synchronization phase P3 according to the new transmission ratio. This synchronization is possible because the new clutch is slipping and therefore always transmits the friction torque during sliding friction. The vehicle load is supported on the slipping clutch and the motor (electric machine) is free to synchronize by torque engagement. In the case of an upshift, the motor must be braked, that is, the motor torque must be reduced in this case, in order to synchronize. Since the electric machine is already running in speed-controlled mode in the current situation, only the setpoint presetting must be adjusted for speed synchronization:

[0050] ω soll (t) = ω aus (t)·i neu

[0051] The information from the speed sensor at the transmission output, ie at the output shaft, and the information from the motor speed at the transmission input, ie at the drive shaft, detects when the speed at the clutch is synchronized.

[0052] To end the shifting process, during the second, preferably arranged, shifting phase P4, a safety torque M is built up again on the new clutch. S , thereby finally synchronizing the speed. In addition, the motor is returned to the torque control mode. During the second transition phase P4, the preset torque M for the motor EM As during the first transition phase P1, it can be determined from the torque specification to be achieved for the torque control, ie including the safety torque, and the specification for the speed control, wherein the factor k(t) is adjusted accordingly, ie it increases from 0 to 1 during the second transition phase. The second transition phase extends within the scope of the second transition time period.

[0053] In the case of a drag downshift, the four phases mentioned in the shifting process are carried out again, but in a different order, more precisely the order of the load change phase and the synchronization phase is interchanged. Thus, the order is: first transition phase P1, synchronization phase P3, load change phase P2, second transition phase P4. Due to the power flow in the clutch, the load change before synchronization to the new speed results in reactive power, since the clutch cannot be engaged in a slipping manner. Thus, the shifting process is carried out in a different order, but is similar in the sense of the invention.

[0054] The first shift phase P1 is implemented just like a traction upshift. Therefore, first the mode is switched to speed control and the safety torque on the clutch of the old gear is simultaneously eliminated.

[0055] In the subsequent synchronization phase P3, the motor must be accelerated during a traction downshift. This is done without a prior load change, so that after the safety torque is eliminated, the torque on the disengaged clutch is kept constant and the speed is predefined for the electric machine according to the new gear. Similar to a traction upshift, the following equation applies:

[0056] ω soll (t) = ω aus (()·i neu

[0057] The load change in the load change phase P2 is carried out similarly to a traction upshift. However, the new (engaged) clutch is engaged at a synchronous speed and the old (disengaged) clutch is slipping. The speed presetting of the above equation is adjusted by the transmission output speed ω at the beginning of the load change phase aus，2 To express the starting value ω0 of the target speed. Preferably, the following equation applies:

[0058]

[0059] This ensures that a clutch that is engaged in incomplete synchronization also engages and in this way the vehicle acceleration is controlled. The first of the summands in this equation can again be regarded as a transition summand and the second summand as a start summand.

[0060] The second transition phase P4 is implemented just as in the case of a traction upshift. Therefore, the safety torque M is built up again on the new clutch. S . In addition, the motor is returned to torque regulation mode.

[0061] The difference between coasting and traction shifting is the power flow in the drive train. During traction driving, the drive train drives the vehicle with the electric machine acting as a motor. Coasting, on the other hand, describes the intervention of the so-called motor brake, for example, when driving downhill or in recuperation mode in an electrically driven vehicle. The electric machine acts as a generator during coasting. Since the order of the two basic phases (load change and synchronization) depends on the power flow in the clutch, they are exactly interchanged during coasting shifting compared to traction shifting. Therefore, during coasting upshifting, synchronization is first performed and then load change is performed, and this is therefore similar to traction downshifting in terms of the sequence. Correspondingly, coasting downshifting is similar to traction upshifting.

[0062] The universal shift logic for implementing all four shift types (traction upshift, traction downshift, coasting upshift, coasting downshift) is Figure 4 . The figure shows by way of example the case of a powershift transmission with two gears. In the case of a plurality of gears, this can be extended accordingly, wherein the shifting logic shown in the figure is applied for each of two gears that follow one another and the shifting request query is generalized accordingly.

[0063] In step 100 , the vehicle is started, ie the electric machine is started, wherein in step 110 the first gear is first engaged.

[0064] In step 115, the gear shifting intention or the desired gear is queried, for example, the position of the gear lever is ascertained. In step 120, it is checked whether the desired gear is higher than the current gear. If this is not the case, the process jumps back to step 115. If this is the case, that is, if the desired gear is higher than the current gear, the vehicle state is ascertained in step 125. Based on the vehicle state, it should be possible to determine whether the vehicle is in towing or in coasting mode.

[0065] In step 130, it is determined whether the vehicle is in traction driving or in coasting driving. If traction driving is present (arrow 135), a load change phase P2 is performed in step 140 before the synchronization phase P3 in step 145, as in combination with Figure 3 and 4 If coasting is present (arrow 150), the synchronization phase P3 is carried out in step 155 before the load change phase P2 in step 160. If provided for, then optionally, as described above, a first transition phase before the load change phase and the synchronization phase and a second transition phase (not shown) after the load change phase and the synchronization phase are carried out in both cases, i.e., the control is changed from the torque control mode to the speed control mode before steps 140 and 145 or 155 and 160 and is changed back to the torque control mode after these steps.

[0066] In step 170 , the shifting process is concluded for both cases, so that the second gear is engaged in the powershift transmission, step 210 , and the vehicle is driven accordingly.

[0067] In step 215, the gear shifting expectation or the desired gear is queried again. In step 220, it is checked whether the desired gear is lower than the current gear. If this is not the case, the process jumps back to step 215. If this is the case, that is, if the desired gear is lower than the current gear, the vehicle state is determined in step 225.

[0068] In step 230, it is determined whether the vehicle is in traction driving or in coasting driving. If coasting driving is present (arrow 235), a load change phase P2 is performed in step 240 before the synchronization phase P3 in step 245, as in combination with Figure 3 and 4 If there is traction driving (arrow 250), the synchronization phase P3 is carried out in step 255 before the load change phase P2 in step 260. If provided, it is also possible to optionally carry out a first transition phase before the load change phase and the synchronization phase and a second transition phase after the load change phase and the synchronization phase in both cases (not shown).

[0069] In step 270 , the shifting process is concluded for both cases, so that according to step 110 the first gear is engaged in the powershift transmission.

Claims

1. A method for shifting gears in a drive device (2) of a vehicle, The drive device comprises an electric motor (4) and a powershift transmission (6), wherein the powershift transmission comprises a drive shaft (10) connected to an output shaft (11) of the electric motor and a driven shaft (12) connected to a running gear (8) in order to move the vehicle, wherein the powershift transmission comprises at least two gears with different transmission ratios (i1, i2), wherein a transmission branch (20, 22) having a clutch (K1, K2) is provided for each of the gears, wherein the clutch is designed to bring about a force-locking connection between the drive shaft and the driven shaft in a closed state, wherein If one of the gears is engaged, the torque between the drive shaft and the output shaft is transmitted exclusively via a single transmission branch of the transmission branches, wherein the electric machine can be regulated in a speed control mode according to a target speed; The method comprises, when shifting from an old gear that is engaged to a new gear that is to be engaged: The load change phase (P2) and the synchronization phase (P3) are implemented in speed regulation mode.

2. The method according to claim 1, wherein the target speed of the speed control mode of the electric motor (4) is changed in the synchronization phase (P3), wherein at the end of the synchronization phase the target speed is determined from the speed of the output shaft taking into account the transmission ratio of the new gear. The method according to claim 2 , wherein the target rotational speed is changed linearly.

4. A method according to any one of the preceding claims, wherein during the load change phase (P2), the clutch (K1, K2) of the transmission branch (20, 22) corresponding to the old gear is cut off or opened, and the clutch (K1, K2) of the transmission branch (20, 22) corresponding to the new gear is connected or closed.

5. The method of claim 4, wherein during the load change phase (P2), if the gearshift is a traction upshift (135) or a coasting downshift (235), the off clutch is engaged and the on clutch is slipping, and if the gearshift is a coasting upshift (150) or a traction downshift (250), the off clutch is slipping and the on clutch is engaged.

6. A method according to any one of the preceding claims, wherein during the load change phase (P2), if the gearshift is a traction upshift (135) or a coasting downshift (235), the target speed is determined from the speed of the output shaft taking into account the transmission ratio of the old gear, and, if the gearshift is a coasting upshift (150) or a traction downshift (250), the target speed is determined from the speed of the output shaft taking into account the transmission ratio of the new gear.

7. A method according to any one of the preceding claims, wherein: If the gearshift is a traction upshift (135) or a coasting downshift (235), a load change phase (140, 240) is implemented before the synchronization phase (145, 245), and if the gearshift is a coasting upshift (150) or a traction downshift (250), the synchronization phase (155, 255) is implemented before the load change phase (160, 260).

8. The method according to any one of the preceding claims, wherein the motor is capable of generating a torque (M) according to a preset torque. EM ) to control and can be adjusted in torque regulation mode, where If one of the gears is engaged, the electric machine is regulated in a torque-controlled mode, wherein the method further comprises the following steps: During a first transition phase (P1) the control of the electric machine is changed from a torque control mode to a torque control mode before a load change phase (P2) and a synchronization phase (P3) are implemented; and During a second transition phase (P4), after the load change phase (P2) and the synchronization phase (P3) have been completed, the control of the electric machine is changed from a speed control mode to a torque control mode.

9. The method according to claim 8, wherein during the first transition phase (P1), the safety torque (M S ), wherein during the first transition time period as the starting torque control mode of the first transition time period, the torque-preset value (M) is weighted by a time-dependent factor (k) which decreases from 1 to 0 within the scope of the first transition time period. MV ) and torque-preset (M DR ) to determine the preset torque.

10. The method according to claim 9, wherein the torque-preset of the speed control mode is determined during a first transition time period based on a target speed of the electric machine, the target speed being determined as the sum of a speed of the electric machine at the start of the transition time period and a time-dependent transition summand determined from the rate of change of the speed of the output shaft taking into account the transmission ratio of the old gear.

11. The method according to any one of claims 8 to 10, wherein a safety torque (M S ), wherein the preset torque is determined during the second transition time period as the starting torque control mode of the second transition time period by the sum of a torque preset weighted by a time-dependent factor rising from 0 to 1 within the scope of the second transition time period and a torque preset of the speed control mode.

12. The method according to claim 11, wherein the torque-preset of the speed control mode is determined during the second transition time period based on the target speed of the electric machine, the target speed being determined as the sum of a starting summand and a time-dependent transition summand, wherein the starting summand is determined from the speed of the output shaft at the beginning of the transition time period taking into account the transmission ratio of the new gear, and wherein the time-dependent transition summand is determined from the rate of change of the speed of the output shaft taking into account the transmission ratio of the new gear.

13. A computing unit (30) which is designed to carry out all method steps of the method according to one of the preceding claims.

14. A drive device (2) for a vehicle, comprising an electric motor (4), a power shift transmission (6), a travel mechanism (6) and a calculation unit (30) according to claim 12; wherein the power shift transmission has a drive shaft (10) connected to the output shaft (10) of the electric motor and a driven shaft (12) connected to the travel mechanism in order to move the vehicle, wherein the power shift transmission has at least two gears with different transmission ratios, wherein a transmission branch (20, 22) having a clutch (K1, K2) is respectively provided for each of the gears, wherein the clutch is configured to cause a force-locking connection between the drive shaft and the driven shaft in a closed state, wherein the electric motor can be adjusted in a speed control mode according to a target speed. 15 . A computer program which, when executed on a computing unit, causes the computing unit to carry out all method steps of the method according to claim 1 .

16. A machine-readable storage medium having stored thereon the computer program according to claim 15.

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