Method for controlling an electric drive machine, control device and work vehicle

Abstract

A method for controlling an electric drive machine (6) of a work vehicle (2) is described. Furthermore, a control device (4) configured to carry out steps of such a method is described. Furthermore, a work vehicle (2) comprising such a control device (4) is described.

Description

[0001] ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0002] Method for controlling an electric drive motor, control device and work vehicle

[0003] Technical field

[0004] A method for controlling an electric drive motor of a work vehicle is described. Furthermore, a control device configured to execute the steps of such a method is described. Finally, a work vehicle equipped with such a control device is described.

[0005] State of the art

[0006] Methods for controlling electric drive motors for work vehicles are known in the prior art. In such work vehicles, both a drive or propulsion system and an additional function, such as a lifting function or a power take-off (PTO), must be supplied with energy. It is known to provide a separate motor for the drive and for the additional function. Energy exchange between the drive and the additional function is possible via these motors, which are, for example, designed as electric machines. DE 102023 110660 A1 describes a first electric machine configured for a drive and a second electric machine configured for a PTO as an additional function. The electric machines can be operated as both motors and generators. Energy exchange between the drive and the PTO is possible via an electrical connection between the two electric machines.For example, energy for the drive can be provided by the electric machine assigned to the drive as well as by the other electric machine assigned to the power take-off shaft.

[0007] As an alternative to at least one of the electric motors, internal combustion engines are commonly used in work vehicles. When additional energy is required for propulsion or other functions, the power output of the internal combustion engine is increased, for example by increasing the injection of fuel. (ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16)

[0008] Fuel is fed into the internal combustion engine. This allows more energy to be provided for propulsion, at least temporarily.

[0009] Description of the invention

[0010] A first aspect concerns a method for controlling the electric drive motor of a work vehicle. This method can be computer-implemented. The drive motor can be an electric motor. The drive motor can be part of the work vehicle's drive system. The work vehicle can be an agricultural, construction, or municipal vehicle. The vehicle can be equipped for material handling. The method can be a control procedure for such an electric drive system in such work vehicles. The control procedure can include controlling and, alternatively or additionally, regulating the electric drive motor.

[0011] The drive motor provides power to propel the work vehicle.

[0012] For example, the drive motor provides electric motor power to propel the work vehicle. This power can be used to move the work vehicle. The power is transmitted to a drive element via mechanical components. The drive element can be at least one wheel and one component of a chain drive. The mechanical components can be at least one gearbox and one shaft. The total power required to propel the work vehicle is transmitted from the electric drive motor to the drive element via these mechanical components. The power provided by the drive motor can be transmitted to one or more drive elements. For example, a rear axle of the work vehicle with two drive elements designed as wheels can be supplied with power from the drive motor via the mechanical components.

[0013] The procedure involves determining a power requirement for the drive motor. The power requirement can be a drive power provided by the drive motor. The power requirement can be a [ZF Friedrichshafen AG file 305945 Friedrichshafen 2025-01-16]

[0014] The power requirement can be the power requested or to be requested from the drive motor. This power requirement can be a target or setpoint power of the drive motor. The power requirement can be mechanical power, for example, the mechanical power provided by the drive motor. The power requirement can be electrical power, for example, the electrical power that must be supplied to the drive motor to provide motive power to propel the vehicle. The power requirement can also be power that is requested from the drive motor to achieve a specific goal, such as reaching or maintaining a certain speed of the vehicle.

[0015] The method further includes determining the performance characteristics of the mechanical components. These performance characteristics can provide information about the mechanical power ratings for which the mechanical components are designed. For example, a shaft, and alternatively or additionally a gearbox as part of the mechanical components, can be designed for a specific mechanical power rating, which is transmitted from the drive motor to the drive torque via the mechanical components. The performance characteristics can also provide information about the mechanical design of the components. For instance, the performance characteristics can indicate the continuous mechanical power that can be transmitted via the mechanical components.For example, the performance characteristic can provide information about the continuous torque and, alternatively or additionally, the continuous rotational speed that can be transmitted from the drive motor to the drive element via a shaft or gearbox as part of the mechanical components. The performance characteristic can define or describe the design of the mechanical components of the drive system.

[0016] The performance characteristics can be determined based on user input. This input can be provided by a user, for example, a driver of the work vehicle. Alternatively, it can be provided by a developer of the work vehicle and stored, for example, in the work vehicle's non-volatile memory. Performance characteristics ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0017] This can be determined using lookup tables. For example, these lookup tables can be populated with information gathered during development work to determine the mechanical design of the mechanical components. This allows, for instance, the determination of performance ranges, such as torque ranges and, alternatively or additionally, speed ranges of the mechanical components, which are permissible for operation. Performance ranges that are not permissible for operation of the mechanical components can also be determined.

[0018] The method involves controlling the drive motor based on the specified power requirement and the specific performance characteristics of the mechanical components. This control can include regulation. The power supplied by the drive motor does not exceed the performance characteristics of the mechanical components. For example, the performance characteristics of the mechanical components for a specific speed and torque range are 150 kW. Therefore, the power supplied by the drive motor is not greater than 150 kW. Any difference between the power supplied by the drive motor and the power requirement is minimized. For example, in one embodiment, the power requirement is 170 kW.With the previously defined power characteristic of 150 kW, the power provided by the drive motor is thus determined to be 150 kW, minimizing any difference between the power requirement and the power provided by the drive motor. If, according to another embodiment, the power requirement is only 140 kW, the power provided by the drive motor is 140 kW, using the same 150 kW power characteristic of the mechanical components.

[0019] For example, the system, consisting of at least the electric drive motor and the mechanical components for which the system is designed, has a power output of 100 kW. This power output can also be referred to as the design system power. The design system power can be the power output for which ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0020] All system components, such as the electric drive and the mechanical components, can be designed for all operating points of the drive, including all speeds and torques. This allows both the electric drive and the mechanical components to provide or transmit 100 kW at any speed and torque. A power range below or up to the maximum design system power (100 kW) can be referred to as the design power range, and both the electric drive and the mechanical components can have such a design power range. Furthermore, at least the electric drive can have a continuous power range. The continuous power range can be a power range with higher power outputs than the design power range.For example, the continuous power range can extend from 100 kW to 200 kW. Within this continuous power range, the electric drive motor can be operated continuously without sustaining damage. However, the mechanical components may not be designed for this power range and could be damaged if operated continuously within this range. Furthermore, the electric drive motor may also have a further power range, a so-called peak power range. The peak power range can exhibit power levels higher than those of the continuous power range.

[0021] For example, the peak power range can extend from 200 kW to 300 kW. Within the peak power range, the electric drive motor can only be operated for short periods, as otherwise permanent damage to the drive motor is to be expected. For example, maximum torques and, alternatively or additionally, maximum speeds are achieved within the peak power range. In the peak power range, for example, both maximum torques and maximum speeds are achieved.

[0022] The drive motor can be controlled in such a way that it operates, at least briefly, in one of the continuous power ranges and the peak power range. This allows for a boost function. (ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16)

[0023] Performance enhancement is implemented and carried out. The procedure can therefore be a control method for performance enhancement. It can be a control method for performance enhancement in the continuous performance range and alternatively or additionally in the peak performance range.

[0024] By determining the performance characteristics of the mechanical components and controlling them based on these characteristics, a design-appropriate boost can be implemented. For example, the performance characteristics can have a function representing the maximum possible power that can be transmitted via the mechanical components. This function could, for instance, be the transmitted drive force as a function of the vehicle's speed. Thus, specific maximum vehicle speeds achievable with the mechanical components can be assigned to specific maximum drive forces that can be transmitted by the mechanical components. Similarly, specific maximum rotational speeds that can be transmitted by the mechanical components can be assigned to specific maximum torques that can be transmitted by the mechanical components.

[0025] By determining the power characteristics and controlling the system based on these characteristics, a design-appropriate boost curve can be used for control. This boost curve can represent the dependence of the control system on the power characteristics of the mechanical components. Thus, for specific power outputs, such as specific drive forces and, alternatively or additionally, specific vehicle speeds, additional power from the drive motor can be released to propel the vehicle. For other power outputs, such as other specific drive forces and, alternatively or additionally, other specific speeds, no additional power from the drive motor can be released. This additional power output can be a level that is maintained at least within the continuous power range.Accordingly, boosting is permitted for those operating points where the mechanical components allow for an increase in performance, whereas boosting is not permitted for all other operating points. This ensures that boosting does not lead to damage to the mechanical components. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16.

[0026] According to a further embodiment, the method can be characterized in that it is also configured to control an electric working machine. The electric working machine can be designed separately from the electric drive machine. The electric working machine can be an electric motor and, for example, be driven by an electric motor. The electric drive machine and the electric working machine can be controlled dependently or independently of each other. The working machine can be regulated and controlled alternatively or additionally. The working machine can also be referred to as a PTO machine, where PTO stands for Power Take-Off.

[0027] For example, the machine can provide power to a power take-off shaft. The system can also be configured to control other electrical machines.

[0028] The procedure may further include determining a performance requirement for the working machine. The performance requirement may be work output provided by the working machine. The performance requirement may be output requested or to be requested from the working machine. The performance requirement may be a target output or a set-in output of the working machine. The performance requirement may be mechanical output, for example, mechanical output provided by the working machine. The performance requirement may be electrical output, for example, the electrical output that must be supplied to the working machine to provide power for a work tool of the work vehicle. The performance requirement may be output requested from the working machine in order to achieve a specific goal, such as being able to perform a specific task with the work tool.

[0029] In addition to the mechanical components already described, the work vehicle may have further mechanical components. These further mechanical components can transmit power provided by the work machine to a working implement of the work vehicle, such as a power take-off shaft. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0030] The method can further include determining the performance characteristics of other mechanical components. These performance characteristics can be determined based on user input. This input can be provided by the driver of the work vehicle, or by a developer of the work vehicle and stored, for example, in the work vehicle's non-volatile memory. Alternatively, the performance characteristics can be determined using lookup tables. For example, these lookup tables can be populated with information gathered during development work to determine the mechanical design of other mechanical components.This allows, for example, the determination of performance ranges, such as torque ranges and, alternatively or additionally, speed ranges of the other mechanical components, which are permitted for operation of these other mechanical components. It also allows the determination of performance ranges that are not permitted for operation of the other mechanical components.

[0031] Furthermore, the method can include controlling the working machine based on a specific power requirement. Control can also be based on the specific performance characteristics of other mechanical components. The control can include regulation. For example, the power provided by the working machine can be prevented from exceeding the performance characteristics of other mechanical components. A difference between the power provided by the working machine and the power requirement can, for example, be minimized.

[0032] In this way, analogous to the control of the drive motor, the driven machine can also be controlled in such a way that the power requirements of the driven machine and, for example, the performance characteristics of other mechanical components are taken into account when controlling the driven machine. This allows for increased power output or a boost function of the driven machine.

[0033] For example, the driven machine, analogous to the drive motor, can be operated in a continuous power range or a peak power range during boosting. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0034] Controlling the drive machine and controlling the working machine can be carried out independently or dependently.

[0035] Known drive systems use a single internal combustion engine as a power source to provide both motive power and work power. When a boost is performed to increase the power output of at least one of the motive power and work power components, a boost curve of the internal combustion engine can be activated to, for example, allow for more power from the engine. This may be necessary, for instance, when some of the internal combustion engine's power is delivered to a power take-off (PTO) shaft as work power, while simultaneously maintaining a constant motive power supply for the vehicle. The presented method provides an alternative control method for the electric drive motor and the electric work machine, representing a different control method for a boost function of internal combustion engines than previously known.This allows for an increase in the performance of the overall system, for example consisting of at least the electric drive motor and the electric working machine, via a different function and a different method.

[0036] According to a further embodiment, the method can be characterized in that the control of the drive motor is carried out based on the specific power requirement of the driven machine. For example, if the specific power requirement for the drive motor increases from one point in time to the next, the power of the driven machine can be reduced when controlling it. This allows the system power to be kept constant.

[0037] According to a further embodiment, the method can be characterized in that determining the performance characteristics of the mechanical components depends on an operating point of the drive machine. Determining the performance characteristics of the other mechanical components can depend on a ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0038] The operating point of the machine can depend on at least one of the following operating parameters: machine speed, rotational speed of a mechanical component, torque at a mechanical component, and power transmitted through the mechanical components. The same can apply to the machine itself. The operating point can be determined using a lookup table and the operating parameters. Operating parameter values ​​can be entered by the user and, alternatively or additionally, read from a sensor. Determining the operating point can be done automatically or semi-automatically.

[0039] According to a further embodiment, the method can be characterized in that it additionally includes determining the power requirement of the drive motor. The method can also include determining the power requirement of the driven machine. For example, determining the power requirement can be performed automatically or at least semi-automatically. This allows for the automatic implementation of a power increase or boost function. The power requirement can be power requested by a function or a user. For example, determining the power requirement can be based on at least one of the acceleration, position, inclination, and orientation of the driven vehicle. Values ​​of these parameters can be acquired using sensors on the driven vehicle.For example, the work vehicle can be equipped with at least one accelerometer, one gyroscope, and one localization system, such as GPS. To acquire further parameters for determining power requirements, the work machine can also be equipped with at least one perception system and one inertial measurement unit. Certain values, for example, acquired with one of the aforementioned sensors, can be sent as signals to a control unit. This control unit can be configured to execute steps of the control procedure as described above. The signals can be transmitted, for example, via the work vehicle's CAN bus. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16.

[0040] Determining the power requirement for the drive motor can be done based on the specified power demand of the drive motor. Similarly, determining the power requirement for the driven machine can be done based on the specified power demand of the driven machine.

[0041] For example, the power demand can at least equal or exceed the power requirement. This allows the system to automatically detect, for instance, that the driver intends to drive up a slope with a specific gradient and that, to maintain a constant speed, the boost function must be activated via the electric drive motor's control system. The power requirement is determined accordingly, and thus the power demand on the drive motor is also determined. Alternatively or additionally, the system can detect that a machine connected to the power take-off (PTO) requires additional power. This can be automatically detected by the system, and by determining the corresponding power requirement and the power demand based on this requirement, a boost can be provided.

[0042] According to a further embodiment, the method can be characterized in that it can also include reading in a user input regarding the power requirement of the drive motor. The method can also include reading in a user input regarding the power requirement of the driven machine. Determining the power requirement of the driven machine can be carried out based on the read in user input. For example, the user, such as the driver, can activate the boost function via the user input. The user can directly influence the power requirement via the user input, thereby indirectly influencing the power demand on the driven machine and, alternatively or additionally, the drive motor and thus the control system.For example, a user can boost at least one of the drive motors and the driven motor. For example, the user can boost at least one of the drive motors. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16.

[0043] and influence the working machine in such a way as to provide an increase in performance.

[0044] According to a further embodiment, the method can be characterized in that it further includes reading in a power characteristic of the drive machine. The method can also include reading in a power characteristic of the driven machine. The power characteristic can contain information on at least one of the design power range, the continuous power range, and the peak power range. Determining the power requirement for the drive machine can be carried out based on the read-in power characteristic of the drive machine. Determining the power requirement for the driven machine can be carried out based on the read-in power characteristic of the driven machine.

[0045] The performance characteristics can therefore contain information about the power range in which the drive motor or working machine can operate for specific speeds of the vehicle or rotational speeds of a tool and specific drive force or working force. For example, the power requirement at high power levels is defined by the peak power range. Furthermore, the power requirement can be defined, absolutely or relatively, below a maximum continuous power for specific time periods, as defined by the continuous power range. This ensures that certain power ranges are not exceeded, thus preventing damage to the drive motor or working machine. In this way, control is carried out according to the performance characteristics of the respective machine, thereby preventing damage.

[0046] According to a further embodiment, the method can be characterized in that the electric drive motor is supplied with electrical energy from an electrical energy storage device. The electric working machine can be supplied with electrical energy from an electrical energy storage device, for example, the same electrical energy storage device to supply the drive motor. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0047] Electrical energy storage can be, for example, a battery. The battery can be supplied with electrical energy from an electrical supply network, which may be external to the work vehicle. Alternatively or additionally, the battery can be supplied with electrical energy diesel-electrically via a generator. Alternatively or additionally, a fuel cell can provide electrical energy and store it temporarily in the battery. Furthermore, the battery can be supplied with electrical energy by a generator. The work vehicle may only have one electrical energy storage device for the drive motor and the working machine, for example, just a battery.

[0048] The method can further include determining the discharge power of the energy storage device. This discharge power can be determined using a sensor connected to the energy storage device and, alternatively or additionally, using a transformer connected to the energy storage device. The discharge power can provide information on the continuous discharge power and, alternatively or additionally, on the short-term discharge power of the energy storage device. For example, the discharge power can indicate the maximum power at which the energy storage device can be continuously or briefly discharged. The discharge power can depend on the charging power of the energy storage device, for example, on a fast-charging power.

[0049] Furthermore, the control of the drive motor can be based on the specified discharge power. The control of the driven machine can also be based on the specified discharge power. For example, the control can be implemented so that the supplied power does not exceed the discharge power. For example, the control can be implemented so that the supplied power does not exceed the maximum short-term discharge power of the energy storage device. The maximum continuous discharge power of the energy storage device can be exceeded for a specific period. The control can be implemented so that the supplied power can exceed the maximum continuous discharge power for the specified period. This can apply to both the drive motor and the driven machine.Accordingly, the sum of the electrical power provided for the drive machine and the working machine can be the ZF Friedrichshafen AG file 305945 Friedrichshafen 2025-01-16.

[0050] The short-term discharge power should never be exceeded, and the continuous discharge power should only be exceeded briefly. This ensures that the energy storage device is not damaged.

[0051] A second aspect concerns a control device configured to execute steps of a method according to an embodiment of the first aspect. Further features, embodiments, and advantages of the second aspect can be derived from features, embodiments, and advantages of the first aspect. Furthermore, features, embodiments, and advantages of the second aspect represent features, embodiments, and advantages of the first aspect.

[0052] A third aspect concerns a work vehicle with a control device according to an embodiment of the second aspect. The work vehicle can be an agricultural, construction, or municipal vehicle. The work vehicle can be a vehicle designed for material handling. The work vehicle can have a working machine that provides power for a PTO function, such as a power take-off shaft. The work vehicle can also have a drive machine. The drive machine and the working machine can be electric machines and, for example, be designed independently of each other. In addition to these electric machines, the work vehicle can have further electric machines, for example, for providing additional drive power or labor. Further features, embodiments, and advantages of the third aspect can be found in the features, embodiments, and advantages of the first and second aspects.Furthermore, the features, designs and advantages of the third aspect represent features, designs and advantages of the first and second aspects.

[0053] Brief description of the characters

[0054] Fig. 1 schematically shows a work vehicle with an electric drive motor and an electric working machine, as well as a control device for controlling the drive motor and the working machine.

[0055] Fig. 2 schematically shows the steps of a method for controlling the drive motor and the driven machine, which are shown in Fig. 1. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0056] Fig. 3 shows different performance ranges of the drive machine shown in Fig. 1.

[0057] Fig. 4 shows a graphical representation of a performance characteristic of mechanical components of the work vehicle from Fig. 1.

[0058] Fig. 5 shows an exemplary operating situation of the drive machine from Fig. 1.

[0059] Detailed description of embodiments

[0060] Fig. 1 schematically shows a work vehicle 2 with a control unit 4. The work vehicle 2 is an agricultural machine with a working implement. The working implement is a plow with moving parts. The work vehicle 2 has an electrical energy storage device 10 designed as a battery. The work vehicle 2 has an electric drive motor 6. The drive motor 6 provides motive power to propel the work vehicle 2. This motive power moves the work vehicle 2. The motive power is transmitted via mechanical components to a drive element. Neither the mechanical components nor the drive element are explicitly shown in Fig. 1. The mechanical components include a gearbox. The drive element includes drive wheels for the work vehicle 2. The drive motor 6 is supplied with electrical energy from the energy storage device 10 via an inverter 12.

[0061] Furthermore, the work vehicle 2 has a working machine 8. The working machine 8 is an electric working machine 8. The electric working machine 8 is configured to provide power to the work vehicle 2. The working machine 8 is configured to provide power to the plow via a power take-off (PTO) shaft. Neither the PTO shaft nor the plow are explicitly shown in Fig. 1. This power is transmitted from the working machine 8 to the plow implement via further mechanical components. Another converter 14, as part of the work vehicle 2, is configured to connect the electric working machine 8 electrically and electronically to the energy storage device 10. The electric energy storage device 10 is configured to power the working machine 8. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0062] to supply electrical energy. The control unit 4 is configured to control the converters 12, 14, so that the supply of electrical energy to the drive machine 6 and the driven machine 8 is controlled. For this purpose, the control unit 4 is configured to execute steps of a procedure shown schematically in Fig. 2.

[0063] Figure 2 schematically shows a method for controlling the electric drive motor 6 of the work vehicle 2. The method is further configured for controlling the electric work machine 8. The method includes reading S1.1 of a user input regarding the power requirement of the drive motor 6. The method also includes reading S1.2 of a user input regarding the power requirement of the work machine 8. A user of the work vehicle 2, here a driver of the work vehicle 2, inputs the user input via a user interface of the work vehicle 2. The user interface is a touchscreen display of the work vehicle 2 (not shown in detail). The driver inputs that increased power is required from the drive motor 6 due to the work vehicle 2 traveling uphill.

[0064] Furthermore, the user indicates that increased power is required due to changing soil conditions for the machine 8.

[0065] The procedure further includes determining (S2.1) the power requirement of the drive motor 6. The procedure further includes determining (S2.2) the power requirement of the working machine 8. Determining (S2.1) the power requirement of the drive motor 6 is based on the input received from the user. Determining (S2.2) the power requirement of the working machine 8 is also based on the input received from the user. Thus, the power requirement of the drive motor 6 is determined based on the user input. The power requirement of the working machine 8 is determined based on the user input. In addition to the user input, determining (S2.1) and (S2.2) the power requirement is also performed based on automatically acquired values ​​for gradient and ground conditions. For example, a sensor detects the inclination of the work vehicle 2.This will result in a slope of a hillside. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16.

[0066] The gradient traversed by the work vehicle 2 is determined. The determination (S2.1) of the power requirement of the drive motor 6 is carried out based on this determined gradient. Furthermore, the ground condition is determined using a sensor, and any difference in ground condition when traversing from a first to a second ground condition is automatically detected by the sensor. Subsequently, the determination (S2.2) of the power requirement of the work vehicle 8 is carried out based on this sensor-determined value.

[0067] Furthermore, the method includes a read-in step S3.1 of a power characteristic of the drive motor 6. The method also includes a read-in step S3.2 of a power characteristic of the driven motor 8. The power characteristics of the drive motor 6 and the driven motor 8 are read into the control unit 4 from a memory (not shown) of the vehicle 2. The power characteristics of the drive motor 6 and the driven motor 8 are defined by different power ranges. These power ranges are a continuous power range, a design power range, and a peak power range. Fig. 3 schematically shows these power ranges and thus provides information on the power characteristics. Fig. 3 schematically shows the power ranges of the drive motor 6. Power ranges of the driven motor 8 are not explicitly shown, but are analogous to the power ranges of the drive motor 6 shown in Fig. 3.In an alternative embodiment, which is not shown here, the performance ranges of the drive machine 6 and the working machine 8 are qualitatively different.

[0068] Figure 3 shows the driving force of the drive motor 6 against the speed of the working vehicle 2. A peak driving force a and a continuous driving force b are plotted. The maximum peak driving force a can be provided by the drive motor 6. The maximum continuous driving force b can be provided by the drive motor 6 for a specific time range. Furthermore, a drive power hyperbola c for a system power of 100 kW is plotted. Below the continuous driving force b lies the design power range A, while above the drive power hyperbola c lies the continuous power range B. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0069] The peak power range C is located at the point where the drive power hyperbola c, the peak drive force a, and the continuous drive force b are located. The force curves and power ranges, as shown in Fig. 3, refer to the power characteristics of the drive machine 6. The driven machine 8 also exhibits a qualitatively similar power characteristic with such or similar power ranges and force curves.

[0070] The method further includes determining S4.1 a power requirement for the drive machine 6. The method also includes determining S4.2 a power requirement for the driven machine 8. Determining S4.1 the power requirement for the drive machine 6 is performed based on the determined power demand of the drive machine 6. Determining S4.2 the power requirement for the driven machine 8 is also performed based on the determined power demand of the driven machine 8. Furthermore, determining S4.1 the power requirement for the drive machine 6 is performed based on the input power characteristic of the drive machine 6. Determining S4.2 the power requirement for the driven machine 8 is also performed based on the input power characteristic of the driven machine 8. Thus, information on the power ranges, as shown in Fig. 3, is used to determine S4.1 and S4.2.2 of the respective performance requirement is used. For example, if at a given time the drive motor 6 is in the design performance range A, the power of the drive motor 6 can be increased to the continuous performance range B for an unlimited time according to the input performance characteristics of the drive motor 6. Furthermore, it can be increased to the peak performance range C for a specific time. The same applies to the driven machine 8.

[0071] The method further includes determining S5.1 a performance characteristic of the mechanical components. The method also includes determining S5.2 a performance characteristic of the other mechanical components. Determining S5.1 and S5.2 of the performance characteristics of the mechanical and other mechanical components depends on an operating point of the drive machine 6 and the driven machine 8, respectively. Fig. 4 schematically shows a representation of the performance characteristics of the mechanical components. (In analogous form: ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16)

[0072] In this way, a performance characteristic of the other mechanical components can be represented. Area D indicates which drive force can be transmitted via the mechanical components for a given speed of the work vehicle 2. Within area D, the mechanical components are designed for the drive force and the respective speed. This means that certain torques and speeds, which are transmitted by the mechanical component, in this case the transmission, are possible. Other speeds and other drive forces that do not correspond to and are not within area D are therefore unsuitable for transmission via the mechanical components. This would lead to permanent damage to the mechanical components.

[0073] It can be seen that for some drive forces and speeds, a power increase from the design power range A to the continuous power range B is possible according to the design of the mechanical components. However, this is not possible for other speeds and drive forces, for example, below approximately 10 km / h and above approximately 30 km / h. Therefore, the mechanical components are designed for a boost between 10 km / h and 30 km / h. Range D extends into continuous power range B only between 10 km / h and 30 km / h, above the drive power hyperbola c. A boost only occurs above the drive power hyperbola c. Below 10 km / h and above 30 km / h, the torque and speed are so high, respectively, that the mechanical component would be permanently damaged by a further increase in power. A power increase or a boost function cannot be activated in these conditions.

[0074] Furthermore, the method includes determining S7 a discharge power of the energy storage device 10. Both a continuous discharge power and a peak discharge power of the energy storage device 10 are determined.

[0075] The method further includes a control S6.1 of the drive machine 6. The method further includes a control S6.2 of the driven machine 8. The control S6.1 of the drive machine 6 is based on the specified performance requirement. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0076] The drive motor 6 is controlled based on the specific performance characteristics of its mechanical components and the specific power requirement of the driven machine 8. Control S6.2 of the driven machine 8 is also controlled based on the specific power requirement of the driven machine 8 and the specific performance characteristics of its other mechanical components. Furthermore, control S6.1 of the drive motor 6 and control S6.2 of the driven machine 8 are both controlled based on the specific discharge power. Control S6.1 of the drive motor 6 is implemented such that the power supplied by the drive motor 6 does not exceed the performance characteristics of its mechanical components. As schematically shown in Fig. 4, control S6.1 of the drive motor 6 is implemented such that the power supplied by the drive motor 6 is always within range D.For the working machine 8, an analogous representation of the performance characteristics of the other mechanical components is not explicitly shown, but it can be derived analogously from Fig. 4. Here too, the control S6.2 of the working machine 8 is carried out in such a way that the power provided by the working machine 8 does not exceed the performance characteristics of the other mechanical components and thus the power does not leave an analogously hatched area.

[0077] Furthermore, the control S6.1 of the drive motor 6 is carried out in such a way as to minimize any difference between the power supplied by the drive motor 6 and the power requirement placed on the drive motor 6. This ensures that the maximum possible power is supplied by the drive motor 6 to drive the work vehicle 2. Likewise, any difference between the power supplied by the work machine 8 and the power requirement placed on the work machine 8 is minimized. This ensures that the maximum possible power is also supplied by the work machine 8.

[0078] By controlling S6.1 and S6.2 based on the specified discharge power, it is ensured that when simultaneously controlling S6.1 of the drive motor 6 and S6.2 of the driven motor 8, the maximum possible discharge power, or peak discharge power, of the energy storage device 10 is not exceeded. This ensures that the required electrical energy is always available for both the ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0079] The drive machine 6 and the working machine 8 can be supplied by the energy storage device 10 without causing permanent damage to the energy storage device 10. Controlling the drive machine 6 based on the specific power requirement for the working machine 8 (S6.1) ensures that control operations S6.1 and S6.2 are not performed independently. Thus, the drive machine 6 and the working machine 8 are controlled in a coordinated manner. In another embodiment, control operation S6.2 of the working machine 8 is also performed based on the specific power requirement for the drive machine 6. In a further alternative embodiment, control operation S6.1 of the drive machine 6 and control operation S6.2 of the working machine 8 are performed independently. In this case, neither control operation S6.1 of the drive machine 6 based on the power requirement for the working machine 8 nor control operation S6.2 is performed independently.2 of the working machine 8 based on the performance requirement of the drive machine 6.

[0080] Fig. 5 schematically shows a section of the power ranges of the drive motor 6. Different drive power hyperbolas c1, c2, and c3 are depicted. Drive power hyperbola c1 corresponds to a vehicle system power of 100 kW, drive power hyperbola c2 to 110 kW, and drive power hyperbola c3 to 120 kW. In the embodiment described here, all the power provided by the work vehicle 2 is used to drive the work vehicle 2. Thus, the drive motor 6 receives 100% of the 100 kW system power, and the work vehicle 80% of the 100 kW system power.

[0081] Furthermore, curve d shows the driving force required for specific speeds of the work vehicle 2 to ascend a given gradient. It can be seen that different vehicle system outputs of either 100 kW, 110 kW, or 120 kW result in different speeds of the work vehicle 2 to ascend the gradient. The drive power hyperbolas c2 and c3 represent a boost of 10% and 20%, respectively, compared to the drive power hyperbola c1. The boost is set so that the limitations on the mechanical components, as indicated in Fig. 4, are always observed. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0082] to prevent permanent damage to the mechanical components. The boost is therefore only provided for certain speed and drive power ranges. Specifically, the boost is only provided in the speed range between 10 and 30 km / h, ensuring that the power output of the drive motor 6 always remains within range D.

[0083] Alternatively, according to another embodiment, the work vehicle 2 not only drives up a slope but also simultaneously tills the ground with the plow, thus requiring energy for the working machine 8. For example, the power distribution is such that 50% of the design system power is transferred to the drive motor 6 and 50% to the working machine 8. Here, too, a boost can be provided for driving along a slope of 10% or 20% for the drive motor 6. However, in this case, the drive power hyperbola shown schematically in Fig. 3 shifts to the left, since it is then no longer 100 kW, but only half of the design system power of 100 kW, namely 50 kW. Therefore, fewer restrictions regarding the performance characteristics of the mechanical components need to be observed when controlling S6.1 of the drive motor 6.This is because the mechanical components are only subjected to 50% of the design system power before the boost. This allows the speed of work vehicle 2 to be maintained by boosting while driving uphill and simultaneously plowing the ground.

[0084] In an alternative embodiment, it is not the drive machine 6 but the working machine 8 that is boosted, for example, because a harder surface is to be plowed and no slope is to be traversed. Before the boost, the drive machine 6 and the working machine 8 again share the design system power equally, at 50% each. Then the power of the working machine 8 is to be boosted, once by 10% and once by 20%. Here, too, the performance characteristics of the other mechanical components are used for controlling S6.2 of the working machine 8, so that a power increase of the working machine 8 can be carried out without damaging the other mechanical components. Thus, a boost of the working machine 8 can be carried out without impairing the power output of the drive machine 6. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0085] This must be done. Thus, the speed of work vehicle 2 can be maintained by boosting. ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16

[0086] Reference mark

[0087] 2 work vehicles

[0088] 4 Control unit

[0089] 6 Drive machine

[0090] 8 working machine

[0091] 10 Energy storage

[0092] 12, 14 inverters

[0093] 51.1, S1.2 Reading in user input

[0094] 52.1, S2.2 Determining a service requirement

[0095] 53.1, S3.2 Reading in a performance characteristic of the working machine /

[0096] drive motor

[0097] 54.1, S4.2 Determining a performance requirement

[0098] 55.1, S5.2 Determining a performance characteristic of the mechanical components / other mechanical components 56.1, S6.2 Controlling the drive machine / driven machine

[0099] S7 Determining the discharge power of the energy storage device

[0100] A Design performance area

[0101] B Continuous power range

[0102] C peak power range

[0103] D area

[0104] a peak driving force

[0105] b Continuous driving force

[0106] c, c1 -c3 Drive power hyperbola

Claims

ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16 Patent claims 1. Method for controlling an electric drive motor (6) of a work vehicle (2), wherein the drive motor (6) provides motive power for driving the work vehicle (2) and wherein the motive power is transmitted via mechanical components to a drive element, the method comprising the steps of: determining (S4.1) a power requirement for the drive motor (6); determining (S5.1) a power characteristic of the mechanical components; controlling (S6.1) the drive motor (6) based on the determined power requirement for the drive motor (6) and based on the determined power characteristic of the mechanical components, wherein a power provided by the drive motor (6) does not exceed the power characteristic of the mechanical components and a difference between the power provided by the drive motor (6) and the power requirement for the drive motor (6) is minimized.

2. Method according to claim 1, characterized in that the method is further configured for controlling an electric working machine (8), wherein the method further comprises determining (S4.2) a power requirement for the working machine (8) and controlling (S6.2) the working machine (8) based on the determined power requirement for the working machine (8).

3. Method according to claim 2, characterized in that the control (S6.1) of the drive machine (6) is carried out based on the specific power requirement of the working machine (8).

4. Method according to one of the preceding claims, characterized in that the determination (S5.1) of the performance characteristics of the mechanical components depends on an operating point of the drive machine (6).

5. Method according to one of the preceding claims, characterized in that the method further comprises determining (S2.1 ) a power requirement of the drive machine (6) and that the determining (S4.1 ) of the ZF Friedrichshafen AG File 305945 Friedrichshafen 2025-01-16 The power requirement for the drive machine (6) is carried out based on the determined power requirement of the drive machine (6).

6. Method according to claim 5, characterized in that the method further comprises reading (S1.1) a user input for the power requirement of the drive machine (6) and that determining (S2.1) the power requirement of the drive machine (6) is carried out based on the read user input.

7. Method according to one of the preceding claims, characterized in that the method further comprises reading (S3.1) a power characteristic of the drive machine (6) and that determining (S4.1) the power requirement for the drive machine (6) is carried out based on the read-in power characteristic of the drive machine (6).

8. Method according to one of the preceding claims, characterized in that the electric drive machine (6) is supplied with electrical energy from an electric energy storage device (10), that the method further comprises determining (S7) a discharge power of the energy storage device (10) and that the control (S6.1) of the drive machine (6) is carried out based on the determined discharge power.

9. Control device (4) which is configured to execute a method according to any one of claims 1 to 8.

10. Work vehicle (2) with a control device (4) according to claim 9.

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