Method and electronic control unit for controlling a multi-speed motor vehicle transmission

Abstract

Method for controlling a multi-speed motor vehicle transmission (4) with an electronic control unit (6), comprising an algorithm implemented in the electronic control unit (6), wherein the algorithm - a current operating point (B2) of the drive motor (2) in the characteristic map of the drive motor (2) is determined from the current data of the drive motor (2), - a current operating point (B3) of the starting element (3) in the characteristic map of the starting element (3) is determined from the current data of the starting element (3) and a current operating point (B4) of the motor vehicle transmission (4) in the characteristic map of the motor vehicle transmission (4) is determined from the current data of the motor vehicle transmission (4), where the algorithm evaluates - at least one predefined characteristic map (BF2) of a drive motor (2) operatively connected to the motor vehicle transmission (4), stored in the electronic control unit (6), - at least one predefined characteristic map (SF3) stored in the electronic control unit (6) of a starting element (3) arranged in the power flow between the drive engine (2) and the motor vehicle transmission (4), - at least one predefined characteristic map (eta4) of the motor vehicle transmission (4) stored in the electronic control unit (6) and - current data for the respective operating point (B2, B3, B4) of the drive motor (2), the starting element (3) and the motor vehicle transmission (4) generates a target value (Δn3_soll) for the operating state of the starting element (3) and transmits this to a slip control device (SSV3) of the starting element (3), and generates a target value (G4_soll) for the gear of the motor vehicle transmission (4) and transmits this to a gear change device (GWV4) of the motor vehicle transmission (4), wherein the algorithm - alternative operating points (B3a) for the starting element (3) are determined in the characteristic map of the starting element (3) in the vicinity of the current operating point of the starting element (3), - alternative operating points (B4a) for the motor vehicle transmission (4) are determined in the characteristic map of the motor vehicle transmission (4) in the vicinity of the current operating point of the motor vehicle transmission (4), and - in the characteristic map of the drive motor (2), alternative operating points (B2a) for the drive motor (2) are determined, which result in conjunction with the alternative operating points (B3a) of the starting element (3) and the alternative operating points (B4a) of the motor vehicle transmission (4), wherein the algorithm - from the current and alternative operating points (B2, B2a; B3, B3a; B4, B4a) of the drive motor (2), the starting element (3) and the motor vehicle transmission (4), a target operating point is determined for each of the drive motor (2), the starting element (3) and the motor vehicle transmission (4), which, in combination with the other two target operating points, minimizes a predefined criterion, and wherein the algorithm - transmits a control command leading to the target operating point of the starting element (3) to the slip control device (SSV3) of the starting element (3) and - transmits a control command leading to the desired operating point of the motor vehicle transmission (4) to the gear change device (GWV4) of the motor vehicle transmission (4).

Description

[0001] The invention relates to a method for controlling a multi-speed motor vehicle transmission with an electronic control unit and to an electronic control unit operated with this method.

[0002] A modern motor vehicle with an automatic or automated multi-speed transmission typically uses a control system in which an electronic control unit determines a suitable transmission gear for the current driving situation and transmits this command to a gearshift device in the transmission. Various methods for determining suitable transmission gears for a given driving situation are known from the prior art. For example, DE 39 22 051 C2 discloses a method for controlling an automatic transmission in which discrete parameters for the current driving activity or the current sportiness of the driver's driving style are determined by evaluating current data for the engine throttle position, engine speed, vehicle lateral acceleration, vehicle speed, vehicle longitudinal acceleration, and vehicle longitudinal deceleration. Each of these parameters is assigned upshift and downshift characteristics for gear selection in the transmission.To determine the current target gear, the parameters are mathematically weighted so that the result of this weighting reflects the transmission gear that matches the driver's current driving style and thus the driver's current request regarding the transmission gear.

[0003] For example, DE 100 41 441 A1 discloses a shifting strategy for an automatic transmission in which various individual criteria—referred to here as "gear selection modules"—each determine a separate target gear, which is then compared with the actual gear and can trigger a shift, taking predefined prohibition criteria into account. For this purpose, various shift prevention mechanisms are provided, each of which can suppress or prohibit a requested shift for specified, standardized operating situations. Both the individual criteria for target gear selection and the shift prevention mechanisms can be processed in parallel.

[0004] Modern automatic transmissions typically feature a torque converter with an integrated torque converter lockup clutch as the starting element, located in the power flow between the engine and the automatic transmission. Typical operating modes for the torque converter lockup clutch are "open," "closed," and "slip-controlled." For example, DE 10 2013 220 398 A1 describes a method for determining a demand-based target slip of such a torque converter lockup clutch. Instead of a few gear-dependent target slip maps, a multitude—for example, 50—different target slip maps are used, which can be activated situationally—i.e., depending on the driving situation—via an index assignment.

[0005] Finally, DE 39 28 653 A1 discloses a method for controlling an internal combustion engine / automatic transmission. The method involves adjusting the current fuel quantity of the internal combustion engine depending on the current position of the motor vehicle's accelerator pedal. At the same time, the gear ratio in the finely geared automatic transmission, and thus the engine speed, is controlled to minimize fuel consumption. The accelerator pedal position determines the fuel quantity per unit of time and thus the engine power. In all operating states, the gear ratio of the automatic transmission is controlled independently of the fuel quantity control so that an engine speed is established that depends solely on the accelerator pedal position.Based on this, the present invention is based on the object of creating a novel method and electronic control unit for controlling a multi-speed motor vehicle transmission, by means of which the motor vehicle with the motor vehicle transmission can be operated in an energy-efficient manner.

[0006] This object is achieved by a method having the features of independent patent claim 1. Advantageous embodiments and further developments of this method emerge from the subclaims. An electronic control unit operated with this method is the subject of independent patent claim 20. Accordingly, a method for controlling a multi-speed motor vehicle transmission with an electronic control unit is proposed, in which an algorithm is implemented in the electronic control unit, wherein the algorithm determines a current operating point of the drive motor in the characteristic map of the drive motor from the current data of the drive motor, a current operating point of the start-up element in the characteristic map of the start-up element from the current data of the start-up element, and a current operating point of the motor vehicle transmission in the characteristic map of the motor vehicle transmission from the current data of the motor vehicle transmission.wherein the algorithm, by evaluating at least one predefined characteristic map stored in the electronic control unit of a drive motor operatively connected to the motor vehicle transmission, at least one predefined characteristic map stored in the electronic control unit of a starting element arranged in the power flow between the drive motor and the motor vehicle transmission, at least one predefined characteristic map of the motor vehicle transmission stored in the electronic control unit, as well as current data on the respective operating point of the drive motor, the starting element, and the motor vehicle transmission, generates a target value for the operating state of the starting element and transmits this to a slip control device of the starting element, as well as generates a target value for the operating state for the gear of the motor vehicle transmission and transmits this to a gear change device of the motor vehicle transmission.

[0007] Furthermore, the algorithm determines alternative operating points for the starting element in the characteristic map of the starting element in the vicinity of the previously determined current operating point of the starting element, alternative operating points for the motor vehicle transmission in the vicinity of the previously determined current operating point of the motor vehicle transmission, and alternative operating points for the drive engine in the characteristic map of the drive motor, which result in conjunction with the alternative operating points of the starting element and the alternative operating points of the motor vehicle transmission. Furthermore, the algorithm determines a target operating point for the drive engine, starting element, and motor vehicle transmission from the previously determined current and alternative operating points of the drive engine, starting element, and motor vehicle transmission, which, in combination with the other two target operating points, minimizes a predefined criterion.The algorithm then transmits a control command leading to this target operating point of the starting element to the slip control device of the starting element and a control command leading to this target operating point of the motor vehicle transmission to the gear change device of the motor vehicle transmission.

[0008] The predefined criterion can be a CO2 emission of the drive engine, but also a fuel consumption of the drive engine, or even an efficiency of the drive engine. If the predefined criterion is a CO2 emission, the predefined characteristic map of the drive engine is preferably a CO2 emission map. If the predefined criterion is fuel consumption, the predefined characteristic map of the drive engine is preferably a fuel consumption map. If the predefined criterion is efficiency, the predefined characteristic map of the drive engine is preferably an efficiency map.

[0009] Thus, compared to the prior art, the algorithm according to the invention enables a reduction in fuel consumption and / or CO2 emissions of the internal combustion engine that drives the multi-step transmission operated with the method according to the invention, since the given operating map of the internal combustion engine is adapted to the situation as a result of the operating point shift initiated by the operating point shift of the motor vehicle transmission and / or by the operating point shift of the starting element.

[0010] If a torque converter is provided as the starting element, the predefined characteristic map of the starting element is preferably a slip characteristic map of this torque converter. In this case, it can be provided that the algorithm generates a target slip of a torque converter lock-up clutch of this torque converter as the target value for the operating state of the starting element.

[0011] If a separating clutch is provided as the starting element, the predefined characteristic map of the starting element is preferably a slip characteristic map of this separating clutch. In this case, it can be provided that the algorithm generates a target slip of this separating clutch as the target value for the operating state of the starting element.

[0012] Preferably, the predefined characteristic map of the motor vehicle transmission is an efficiency characteristic map, which can advantageously be predefined depending on the gear.

[0013] In an advantageous embodiment of the invention, it is proposed that all predefined characteristic maps processed by the algorithm are predefined as a function of temperature, so that the real friction conditions in the units involved can be taken into account more precisely.

[0014] The algorithm can determine the alternative operating points by varying the selectable gears in the vehicle transmission starting from the current gear. The algorithm can also determine the alternative operating points by varying the slip in the starting element. Preferably, the algorithm links the variation in the selectable gears with the variation in the slip.

[0015] In a further development of the invention, it can be provided that the algorithm, when determining the alternative operating points of the drive motor, takes into account a torque of an additional electric machine with which the motor vehicle transmission can be driven.

[0016] As another development of the invention, it is proposed that the transmission of the setpoint values ​​for the operating state of the starting element and for the gear of the motor vehicle transmission be suppressed, and that the starting element and motor vehicle transmission be operated with an operating or shifting strategy independent of the algorithm if at least one predefined condition is met. Thus, to ensure the desired rapid heating of the drive engine and thus to improve the exhaust gas quality of the drive engine, it can be provided, for example, that the transmission of the setpoint value is suppressed if warm-up of the drive engine and / or motor vehicle transmission is detected or if a predefined lower temperature threshold for the drive engine and / or motor vehicle transmission and / or ambient air is undershot.As overheating protection for the transmission and starting element, it can be provided, for example, that the setpoint transmission is suppressed if a predefined upper temperature threshold for the drive motor and / or vehicle transmission and / or ambient air t is exceeded. To avoid overriding an explicit driver request, it can be provided, for example, that the setpoint transmission is suppressed if a driver request for "sport" and / or "manual gear selection" is detected. To prevent malfunctions, it can be provided, for example, that the setpoint transmission is suppressed if an emergency operation of the starting element and / or vehicle transmission is detected.

[0017] The invention is explained in more detail below with reference to the drawings. In the drawings: Fig. 1 a diagram of a powertrain in a motor vehicle; Fig. 2 a block diagram to illustrate the method according to the invention; and Fig. 3 a flow chart to illustrate the method according to the invention.

[0018] The invention relates to a method and a control device for controlling a multi-speed motor vehicle transmission in a Fig. 1 shows an exemplary drive train. The motor vehicle is designated herein by 1, the motor vehicle transmission embodied as a multi-step transmission by 4, a drive motor embodied as an internal combustion engine and intended to drive the motor vehicle transmission 4 by 2, and a starting element arranged in the power flow between the drive motor 2 and the motor vehicle transmission 4 by 3. On the output side, the motor vehicle transmission 4 is connected or operatively connected to an output 5 of the motor vehicle 1. The starting element 3 can be designed, for example, as a torque converter with an integrated torque converter lock-up clutch, but also, for example, as a transmission-external or transmission-internal separating clutch.For controlling the motor vehicle transmission 4 and starting element 3, an electronic control unit 6 is provided which, on the one hand, receives signals from the drive motor 2, starting element 3 and transmission 4 and, on the other hand, transmits control signals to a gear change device GWV4 assigned to the motor vehicle transmission 4 and to a slip control device SSV3 assigned to the starting element 3.

[0019] Fig. 2 shows a highly simplified block diagram to illustrate the method according to the invention. Reference numeral 6 again denotes the electronic control unit, which is signal-linked to the environment U, motor vehicle 1, drive motor 2, transmission 4, and starting element 3. As input signals, control unit 6 evaluates, for example, current data on an air temperature TU of the environment U, a speed v1 of motor vehicle 1, a gear selector w1 operable by the driver of motor vehicle 1, an engine temperature T2 of drive motor 2, an engine speed n2 of drive motor 2, an engine torque M2 of drive motor 2, a transmission temperature T4, a transmission input speed n4, a gear G4 engaged in transmission 4, and an actual slip Δn3 prevailing in starting element 3.As output signals, the control unit 6 transmits, on the one hand, a target gear G4_soll to be set in the transmission 4 to the gear change device GWV4 of the transmission 4, and, on the other hand, a target slip Δn3_soll to be set in the starting element 3 to the slip control device SSV3 of the starting element 3. In the illustrated embodiment, the starting element 3 and the transmission 4 are interpreted as separate components. From . Fig. 2 it is further evident that the electronic control unit 6 has memory areas SP6 in which various predefined data are stored, some of which are assigned to the drive motor 2, some to the starting element 3 and some to the transmission 4.

[0020] The predefined engine data stored in memory area SP6 include an operating map BF2 for drive engine 2, a minimum engine speed n2_min, and a maximum engine speed n2_max. The operating map BF2 maps, for example, curves of equal specific fuel consumption as a function of engine speed and engine load (engine torque or an equivalent value). It is advantageous if this operating map BF2 is also predefined as a function of engine temperature (engine oil temperature or engine coolant temperature) so that drag losses and the friction coefficient behavior in drive engine 2 can be taken into account more precisely. The minimum engine speed n2_min is a limit value that must not be undershot during operation to protect against stalling. The maximum engine speed n2_max is a limit value that must not be exceeded during operation to protect against overspeeding.

[0021] A slip map SF3 is stored in memory area SP6 as predefined starting element data. Depending on the type of starting element used, the slip map SF3 represents, for example, the efficiency of a torque converter, a torque converter lock-up clutch, or a separating clutch as a function of slip and load (torque or an equivalent value). Common torque converter maps are known, for example, from VDI 2153 of the VDI manual "Getriebetechnik II" (April 1994 edition).

[0022] An efficiency map eta4 of transmission 4 and a shift map GF4 of transmission 4 are stored in memory area SP6 as predefined transmission data. The efficiency map eta4, for example, maps the transmission efficiency in the discrete gear stages of the transmission as a function of the transmission input speed and transmission load (transmission input torque or an equivalent value). It is advantageous if this efficiency map eta4 is also predefined as a function of the transmission temperature (transmission oil temperature or transmission coolant temperature or, alternatively, air temperature) so that the drag losses and the friction coefficient behavior in transmission 4 can be taken into account more precisely. The shift map GF4 maps the possible gears to which transmission 4 can shift based on the current actual gear G4.For this purpose, the shift map GF4 can, for example, have a table with permissible gears depending on vehicle speed v1 and / or transmission input speed n4, but also additional situational or permanent shift prevention conditions. Normally possible shifts can, for example, be specifically suppressed when warm-up of drive engine 2 and / or transmission 4 is detected, when a predefined lower threshold for engine temperature T2 and / or transmission temperature T4 and / or air temperature TU is undershot, when a predefined upper threshold for engine temperature T2 and / or transmission temperature T4 and / or air temperature TU is exceeded, when a driver request "Sport" is detected, when a driver request "manual gear selection" is detected via gear selector device w1, and / or when emergency operation of starting element 3 and / or transmission 4 is detected.

[0023] Fig.Figure 3 shows a flowchart illustrating the method according to the invention with the algorithm according to the invention. The electronic control unit, which is signal-connected to the environment U, motor vehicle 1, drive motor 2, drive element 3, and transmission 4, is again designated 6. The system boundaries are highlighted as dashed lines.

[0024] In a method step S1, the algorithm reads the current value of the air temperature TU measured in the environment U into the control unit 6, so that the current air temperature TU is subsequently available for other method steps, which is indicated in the figure by dotted lines.

[0025] In a method step S2, the algorithm reads the current values ​​of engine temperature T2, engine speed n2 and engine torque M2 provided by the drive motor 2 into the control unit 6 and, in a subsequent method step S3, determines the current operating point B2 of the drive motor 2 in this operating map BF2 from these measured values ​​T2, n2, M2 using the operating map BF2 of the drive motor 2 stored in the memory area of ​​the control unit 6 and, if applicable, the current air temperature TU. The current air temperature TU can, for example, serve as a substitute value for an implausible value of the engine temperature T2. In a subsequent method step S4, the algorithm according to the invention determines alternative operating points B2a for the drive motor 2 in its operating map BF2, the details of which will be discussed in more detail later.

[0026] In a method step S5, the algorithm reads the current value of the actual slip Δn3 present in the starting element 3, provided by the slip control device SSV3 of the starting element 3 assigned to the starting element, into the control unit 6 and, in a subsequent method step S6, determines the current operating point B3 of the starting element in this slip map SF3 from this measured value Δn3 using the slip map SF3 of the starting element stored in the memory area of ​​the control unit 6. If the slip map SF3 is stored as a function of temperature, then in method step S6, for example, a current transmission temperature T4 or a temperature measured directly in the starting element or even the current air temperature TU can be used to determine the current operating point B3 of the starting element 3. This is indicated by dotted lines in the figure.For example, the air temperature TU can also serve as a substitute value for an implausible value of the transmission temperature T4. In a process step S7 following process step S6, the algorithm determines alternative operating points B3a for the starting element in its slip map SF3, preferably by varying the slip in the starting element 3 in discrete steps based on the currently existing actual slip Δn3, so that each of these slip values ​​deviating from the actual slip Δn3 generates its own alternative operating point B3a for the starting element 3 in the slip map SF3.

[0027] In a method step S8, the algorithm reads the current values ​​of transmission temperature T4, transmission input speed n4 and actual gear G4 provided by transmission 4 into control unit 6 and, in a subsequent method step S9, determines the current operating point B4 of transmission 4 in this efficiency map eta4 from these measured values ​​T2, n2, M2 using the efficiency map eta4 of transmission 4 stored in the memory area of ​​control unit 6 and, if applicable, the current air temperature TU. The current air temperature TU can, for example, serve as a substitute value for an implausible value of transmission temperature T4. In a method step S10 following method step S9, the algorithm determines alternative operating points B4a for transmission 4 in its efficiency map eta4 using the shift map GF4.As already described, the shift map GF4 represents, for example, in table form, the possible gears to which transmission 4 can and may shift based on the current actual gear G4, thus also taking into account currently valid situational or permanent prohibitions on individual gears. Preferably, each of the other permissible gears based on the current actual gear G4 generates its own alternative operating point B4a for transmission 4 in the efficiency map eta4.

[0028] In a method step S11, the algorithm reads the current operating point B2 of the drive motor 2 determined in method step S3 in the operating map BF2 of the drive motor 2, the current operating point B3 of the starting element 3 determined in method step S6 in the slip map SF3 of the starting element 3, and the current operating point B4 of the transmission 4 determined in method step S9 in the efficiency map eta4 of the transmission 4. Furthermore, in method step S11, the algorithm reads the alternative operating points B3a of the starting element 3 determined in method step S7 in the slip map SF3 of the starting element 3, and the alternative operating points B4a of the transmission 4 determined in method step S10 in the efficiency map eta4 of the transmission 4.Each of these alternative operating points B3a of the starting element 3 and each of these alternative operating points B4a of the transmission 4, if implemented, would cause a shift in the current operating point B2 of the engine 2 in its operating map BF2. Consequently, in method step S11, the algorithm transmits all alternative operating points B3a of the starting element 3 and all alternative operating points B4a of the transmission 4 to method step S4, in which all alternative operating points B2a in the operating map BF2 of the engine 2 are then determined, which result in conjunction with the individual alternative operating points B3a, B4a of the starting element 3 and transmission 4.Alternatively, in method step S11, a preselection can be made as to which of the alternative operating points B3a, B4a of starting element 3 and transmission 4, individually or in combination, are expected to result in a sensible or at least promising operating point shift in the operating map BF2 of engine 2, in which case only the preselection is transmitted to method step S4.

[0029] The alternative operating points B2a of engine 2 determined in method step S4 are read back into method step S11. Then, in method step S11, the algorithm determines a target operating point for each of engine 2, starting element 3, and transmission 4 from the current and alternative operating points B2, B2a, B3, B3a, B4, B4a of engine 2, starting element 3, and transmission 4. This target operating point, in combination with the other two target operating points, minimizes a predefined criterion. Suitable criteria include, in particular, CO2 emissions of engine 2, fuel consumption of engine 2, and efficiency.The algorithm then transmits a control command leading to the target operating point of the starting element 3 – here, for example, the target slip Δn3_soll – to the slip control device SSV3 of the starting element 3 and a control command leading to the target operating point of the transmission 4 – here, for example, the target gear G4_soll – to the gear change device GWV4 of the transmission 4.

[0030] Thus, the algorithm according to the invention makes it possible to set an optimized operating point in the operating map BF2 of the engine 2 for each driving situation. Reference symbol 1 motor vehicle 2 drive motor 3 Starting element 4 gearboxes 5 downforce 6 electronic control unit v1 Vehicle speed w1 gear selector n2 engine speed n2_max maximum engine speed n2_min minimum engine speed B2 current operating point of the drive motor B2a alternative operating point of the drive motor BF2 operating map of the drive motor M2 engine torque T2 engine temperature Δn3 actual slip in the starting element Δn3_soll Target slip in the starting element B3 current operating point of the starting element B3a alternative operating point of the starting element SF3 slip characteristic map of the starting element SSV3 slip control device of the starting element n4 Gearbox input speed B4 current operating point of the gearbox B4a alternative operating point of the transmission eta4 efficiency map of the transmission G4 Actual gear G4_soll Target gear GF4 transmission shift map GWV4 Gearbox gear change device T4 transmission temperature S1 to S13 process steps SP6 memory area of ​​the electronic control unit U Environment TU air temperature

Claims

[1] Method for controlling a multi-speed motor vehicle transmission (4) with an electronic control unit (6), comprising an algorithm implemented in the electronic control unit (6), wherein the algorithm - a current operating point (B2) of the drive motor (2) in the characteristic map of the drive motor (2) is determined from the current data of the drive motor (2), - a current operating point (B3) of the starting element (3) in the characteristic map of the starting element (3) is determined from the current data of the starting element (3) and a current operating point (B4) of the motor vehicle transmission (4) in the characteristic map of the motor vehicle transmission (4) is determined from the current data of the motor vehicle transmission (4), where the algorithm evaluates - at least one predefined characteristic map (BF2) of a drive motor (2) operatively connected to the motor vehicle transmission (4), stored in the electronic control unit (6), - at least one predefined characteristic map (SF3) stored in the electronic control unit (6) of a starting element (3) arranged in the power flow between the drive engine (2) and the motor vehicle transmission (4), - at least one predefined characteristic map (eta4) of the motor vehicle transmission (4) stored in the electronic control unit (6) and - current data for the respective operating point (B2, B3, B4) of the drive motor (2), the starting element (3) and the motor vehicle transmission (4) generates a target value (Δn3_soll) for the operating state of the starting element (3) and transmits this to a slip control device (SSV3) of the starting element (3), and generates a target value (G4_soll) for the gear of the motor vehicle transmission (4) and transmits this to a gear change device (GWV4) of the motor vehicle transmission (4), wherein the algorithm - alternative operating points (B3a) for the starting element (3) are determined in the characteristic map of the starting element (3) in the vicinity of the current operating point of the starting element (3), - alternative operating points (B4a) for the motor vehicle transmission (4) are determined in the characteristic map of the motor vehicle transmission (4) in the vicinity of the current operating point of the motor vehicle transmission (4), and - in the characteristic map of the drive motor (2), alternative operating points (B2a) for the drive motor (2) are determined, which result in conjunction with the alternative operating points (B3a) of the starting element (3) and the alternative operating points (B4a) of the motor vehicle transmission (4), wherein the algorithm - from the current and alternative operating points (B2, B2a; B3, B3a; B4, B4a) of the drive motor (2), the starting element (3) and the motor vehicle transmission (4), a target operating point is determined for each of the drive motor (2), the starting element (3) and the motor vehicle transmission (4), which, in combination with the other two target operating points, minimizes a predefined criterion, and wherein the algorithm - transmits a control command leading to the target operating point of the starting element (3) to the slip control device (SSV3) of the starting element (3) and - transmits a control command leading to the desired operating point of the motor vehicle transmission (4) to the gear change device (GWV4) of the motor vehicle transmission (4). [2] Method according to claim 1, characterized by that the predefined criterion is a CO2 emission. [3] Method according to claim 2, characterized by that the predefined map of the drive motor (2) is a CO2 emission map. [4] Method according to claim 1, characterized by that the predefined criterion is fuel consumption. [5] Method according to claim 4, characterized by that the predefined map of the drive engine (2) is a fuel consumption map (BF2). [6] Method according to claim 1, characterized by that the predefined criterion is an efficiency. [7] Method according to claim 6, characterized by that the predefined characteristic map of the drive motor (2) is an efficiency map. [8] Method according to one of claims 1 to 7, characterized by that the predefined characteristic map of the starting element (3) is a slip characteristic map (SF3) of a torque converter provided as a starting element. [9] Method according to claim 8, characterized by that a target slip (Δn3_soll) of a torque converter lock-up clutch of the torque converter is generated as a target value for the operating state of the starting element (3). [10] Method according to one of claims 1 to 7, characterized by that the predefined characteristic map of the starting element (3) is a slip characteristic map of a separating clutch provided as a starting element (3). [11] Method according to claim 10, characterized by that a target slip of the separating clutch is generated as a target value for the operating state of the starting element (3). [12] Method according to one of claims 1 to 11, characterized by that the predefined characteristic map of the motor vehicle transmission (4) is an efficiency characteristic map (eta4). [13] Method according to claim 12, characterized by that the efficiency map (eta4) is predefined depending on the gear. [14] Method according to one of claims 1 to 13, characterized by that the predefined maps are predefined depending on the temperature. [15] Method according to one of claims 1 to 14, characterized bythat the algorithm determines the alternative operating points (B2a, B3a, B4a) by varying gears that can be switched in the motor vehicle transmission (4) starting from the current gear (G4). [16] Method according to one of claims 1 to 14, characterized by that the algorithm determines the alternative operating points (B2a, B3a, B4a) by varying slip (Δn3) in the starting element (3). [17] Method according to claims 15 and 16, characterized by that the algorithm links the variation of the shiftable gears with the variation of the slip. [18] Method according to one of claims 1 to 17, characterized by that the algorithm takes into account a torque of an additional electric machine with which the motor vehicle transmission (4) can be driven when determining the alternative operating points (B2a) of the drive motor (2). [19] Method according to one of claims 1 to 18, characterized bythat the transmission of the setpoint values ​​for the operating state of the starting element (3) and for the gear of the motor vehicle transmission (4) is suppressed and the starting element (3) and motor vehicle transmission (4) are operated with an operating or switching strategy independent of the algorithm if at least one of the following conditions is met: - warm-up of drive motor (2) and / or motor vehicle transmission (4) detected; - predefined lower temperature threshold for drive motor (2) and / or motor vehicle transmission (4) and / or ambient air is undercut; - predefined upper temperature threshold for drive motor (2) and / or motor vehicle transmission (4) and / or ambient air exceeded; - Driver request “Sport” recognized; - Driver request “manual gear selection” recognized; - Emergency operation of starting element (3) and / or vehicle transmission (4) detected. [20] Electronic control unit (6) for controlling a multi-speed motor vehicle transmission (4), characterized by an algorithm implemented in the electronic control unit (6) according to one or more of claims 1 to 19.

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