Drive system and method for a drivetrain of a work machine

Abstract

The invention relates to a drive system for a drivetrain of a work machine (1), comprising • a plurality of actuating devices (2) for manual user input, wherein each actuating device (2) has a signal interface, • a braking device (3), a drive motor (4) and a transmission (5) having a respective signal interface, • an environment monitoring system (6) having a signal interface, • a vehicle control unit (7) having at least one signal interface, which is connected to the signal interface on the respective actuating device (21, 22, 23) in a signal-transmitting manner and is designed to control drivetrain functions (9) in accordance with the manual user inputs, and • a user assistance interface (8), which is connected to the signal interface of the environment monitoring system (6) in a signal-transmitting manner and is designed to control drivetrain functions (9) in accordance with the environment monitoring system (6) and separately from the vehicle control unit (7). The invention also relates to a method for operating the drive system, wherein manual user inputs are first evaluated by the vehicle control unit (7) and then used to control drivetrain functions (9), wherein environment monitoring signals are provided separately from the signals of the vehicle control unit (7) at the user assistance interface (8) in order to control the drivetrain functions (9).

Description

[0001] ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27

[0002] Drive system and method for a drive train of a working machine

[0003] The invention relates to a drive system for a drive train of a working machine. Furthermore, the invention also relates to a method for operating such a drive system for a drive train of a working machine.

[0004] In this context, "working machines" refers in particular to powered or self-propelled working machines, including, but not limited to, construction machines such as wheel loaders, graders or dumpers, agricultural machines such as tractors / farm tractors with or without attachments or trailers or harvesting machines, forestry machines such as forwarders or harvesters, or industrial trucks such as forklifts, pallet trucks or telescopic handlers.

[0005] Systems for obstacle detection and collision avoidance are known from the prior art, also in relation to construction machinery. For example, JP 7 374 021 B2 shows a construction machine with an obstacle detection system and a control unit. A detection device of the obstacle detection system detects obstacles and the distance between the construction machine and the obstacle. The control unit sends a signal to electromagnetically controlled valves of the transmission when the distance to this obstacle is shorter than the stored braking distance at maximum braking force. This initiates a change of direction in addition to the braking process, thereby increasing the deceleration of the construction machine. The control unit thus controls the engine, brakes, and transmission depending on signals from the obstacle detection system.The control unit is therefore designed to receive and process signals relating to the detected obstacle and the distance between the machine and the obstacle.

[0006] The object of the present invention is to provide an alternative drive system and a method for a working machine. In particular, the drive system should feature improved user support and low latency for controlling drivetrain functions. This object is achieved with a drive system according to claim 1 and a method according to claim 4 (ZF Friedrichshafen AG File 303465, Friedrichshafen, November 27, 2024). Embodiments are the subject of the dependent claims.

[0007] According to a first aspect, a drive system for a drive train of a working machine is provided, comprising several actuating devices for manual user input, each actuating device having a signal interface, a braking device, a drive motor, a gearbox, an environmental monitoring system with a signal interface, a vehicle control unit with at least one signal interface which is connected to the signal interface on the respective actuating device and is configured to control drive train functions according to the manual user inputs, and a user support interface which is connected to the signal interface of the environmental monitoring system and is configured to control drive train functions according to the environmental monitoring system and separately from the vehicle control unit.

[0008] This creates a separation between the control of the powertrain functions via the respective actuator, which can be understood as a human-machine interface and is designed, for example, as the accelerator pedal, brake pedal, or direction selector switch, and the operator support interface, which receives signals directly from the environmental monitoring system, i.e., without going through the vehicle control unit. Separating the signal paths reduces the latency for controlling the powertrain functions via the user support interface and also creates different control options for powertrain functions.

[0009] The user interface allows for the adjustment of the control functions independently of the vehicle control unit, thereby enabling a more efficient configuration of how the signal data from the environmental monitoring system is applied. This improves usability and thus also user comfort. The separation and differentiation between user-initiated driving functions and those initiated by the environmental monitoring system via the user interface is also addressed. (ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27)

[0010] Support functions help the user adapt the system more quickly to their needs. For example, by directly controlling specific powertrain functions or by adapting the control of existing powertrain functions via a different parameter set that applies only to the user support interface, the response behavior of the powertrain can be changed in certain situations or new situations can be covered.

[0011] Powertrain functions are applied, for example, to work and driving tasks to provide the user, i.e., the operator of the work machine, with the best possible performance and efficiency from the powertrain. The coordination during driving and work operations does not necessarily have to match user assistance situations. User assistance is particularly necessary in critical situations, such as to avoid collisions with objects located in the work machine's direction of travel. When user assistance is activated, it can override the control initiated by the user. By separating the signal paths, this reduces the latency for controlling the powertrain functions via the user assistance interface. Furthermore, this separation of controls also allows for better differentiation of the effects of changes to a powertrain function.

[0012] Therefore, the user support interface not only enables faster and more efficient control but also improves the maintenance of powertrain functions, as malfunctions can be attributed to the respective interface. Furthermore, vehicle diagnostics are enhanced when using separate fault codes, facilitating faster fault detection and assignment. The user support interface is used only for powertrain functions that can be supported by the environmental monitoring system. This also serves, in particular, as an intermediate step towards autonomous driving functions, providing more efficient operator support.Furthermore, the implementation of the user support interface ensures future scalability of the functionality, as adjustments only need to be made to one part of the control system, namely the signal path of the user support interface, and are therefore limited in scope. New functions related to autonomous driving can be integrated via the user support interface. This ensures the expandability of the drive system. In particular, sustainability and resource conservation can also be increased because the scalability provided by the user support interface allows for the continued use of the drive system for future requirements.

[0013] The vehicle control unit receives a signal relating to the drivetrain functions at its at least one signal interface, based on user input at the respective actuating device, and controls the braking system, the drive motor, and / or the transmission according to the received signal. The braking system is designed to brake or decelerate at least one wheel of the machine. The braking system includes a service brake, for example, in the form of a disc brake, drum brake, or the like. The drive motor is designed to drive and accelerate the machine and provides drive torque, which is transmitted via the transmission to at least one wheel, preferably to at least two or all wheels of the machine. The transmission is designed to increase the drive torque and also has a variety of additional functions.For example, the gearbox can be used to reverse the direction of rotation and thus change the direction of travel.

[0014] Powertrain functions are controlled via the control of the braking system, the drive motor, and the transmission. The vehicle control unit is connected to the actuators, the braking system, the drive motor, and the transmission via signal transmission. The vehicle control unit is configured to receive user inputs, generate control signals based on the received user inputs, and transmit these control signals to the braking system, the drive motor, and the transmission. For example, the signal transmission connection can be wired, wireless, or optical. A signal transmission connection is a communicating connection in which signals are transmitted as switching, control, or command signals. The respective signal interface enables data exchange and thus communication between the connected components.The respective signal interface can be integrated into the respective component or be an integral part of it. For example, the signal interface is designed to acquire signal data in the form of an electrical voltage or an electrical current.

[0015] According to one embodiment, the environmental monitoring system comprises an imaging sensor, a radar sensor, and / or a LiDAR sensor. An environmental monitoring system is a sensor-based unit that continuously monitors the surroundings of the machine and detects potential obstacles, such as objects, vehicles, or people. Typically, the environmental monitoring system uses sensors such as cameras, radar sensors, and / or LiDAR sensors to detect the position, movement, and distance of objects in the vehicle's environment. Upon detecting an object or obstacle, the environmental monitoring system generates, for example, a deceleration signal that is transmitted via the user interface directly to the braking device or brake control unit, and / or to the transmission or transmission control unit, and / or to the drive motor or drive motor control unit, and processed directly there, without being routed through the vehicle's control unit.Powertrain functions can then be initiated directly at the respective device to decelerate the drive motor in this case. For example, a drive motor or transmission function can be activated to decelerate the vehicle, first to reduce the speed of the machine and, if necessary, to avoid a collision. Alternatively or additionally, a braking function can be activated to directly and rapidly decelerate the machine. The sensors of the environmental monitoring system provide precise detection of the surroundings and enable the control of the powertrain functions based on objects or obstacles in the machine's vicinity. Alternatively, the environmental monitoring system can make the sensor data available at the user interface, allowing other internal or external devices to access it.

[0016] According to one embodiment, the drivetrain comprises a powershift transmission or a CVT transmission that allows stepless adjustment of the gear ratio. ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27

[0017] A powershift transmission is a transmission that can shift between different gears under load without interrupting power transmission to the drivetrain. This is achieved through clutches and shift elements that allow gear changes under load, thus providing a high degree of continuity in traction. In contrast, a CVT (Continuously Variable Transmission) is a continuously variable transmission that allows for a continuous adjustment of the gear ratio. It utilizes a system with variable pulleys and belts or hydrostatic power distribution, enabling smooth acceleration and braking without gear changes. Through targeted shifts, such as a reversing function, the powershift transmission can generate strong deceleration torque by building up a force opposing the driving resistance.The CVT transmission, on the other hand, uses its continuously variable transmission ratio to achieve smoother deceleration and to maintain standstill through its hydrostatic power sharing.

[0018] In one embodiment, the user support interface is integrated into a control unit of the transmission. In an alternative embodiment, the user support interface is integrated into a control unit of the braking system. Regardless of whether the user support interface is integrated into the transmission or the braking system, its integration into the software architecture is achieved via the bus system of the machine. The user support interface can be used for all drivetrain functions and provides an additional control option, which, in addition to its own diagnostic function in the event of a fault, also improves the safety functions of the machine.

[0019] According to a second aspect, a method for operating a drive system according to the first aspect is provided, wherein manual user inputs are first evaluated by the vehicle control unit and then used to control powertrain functions, wherein environmental monitoring signals are separated from the vehicle control unit signals and provided at the user support interface to control powertrain functions. ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27

[0020] For example, data signals for changing the speed and / or torque of the drive motor are provided via the user interface. In particular, the speed and / or torque of the drive motor is reduced. Alternatively or additionally, data signals for changing the gear ratio are provided via the user interface. For example, gears can be changed or a reversing function of the transmission can be initiated. Alternatively or additionally, data signals for changing the braking torque of the braking system are provided via the user interface. In particular, the braking torque of the braking system is increased. Preferably, data signals for decelerating the driven machine are provided via the user interface.

[0021] According to one embodiment, the user support interface is configured for bidirectional communication with the environmental monitoring system and can define areas for environmental monitoring. Thus, in addition to activating and controlling powertrain functions, the user support interface can define areas for monitoring the sensors of the environmental monitoring system and can therefore also control the environmental monitoring system. This significantly expands the functionality of the system.

[0022] According to a third aspect, a vehicle is provided that includes a drive system according to the first aspect. The vehicle may have one or more drive trains that can interact. It is conceivable that the drive train has a differential or is connected to a differential on an axle of the vehicle, which can distribute the drive power of the drive train to the drive wheels of the respective axle of the vehicle. The vehicle is preferably a working machine. The above definitions, as well as descriptions of the technical effects, advantages, and advantageous embodiments of the drive system according to the first aspect, also apply mutatis mutandis to the method according to the second aspect and to the vehicle according to the third aspect, and vice versa. ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27

[0023] An embodiment of the invention will now be explained in more detail with reference to the two drawings, wherein identical or similar elements are provided with the same reference numeral. Here,

[0024] Fig. 1 shows a block diagram of a drive system for a drive train of a working machine and

[0025] Fig. 2 shows a highly simplified schematic representation of a working machine with such a drive system.

[0026] Figure 1 shows a highly simplified representation of a drive system for the drive train of a machine 1, which is shown in Figure 2. The drive system comprises several actuating devices 2 for manual user input. For example, one of the actuating devices 2 is configured as an accelerator pedal. For example, one of the actuating devices 2 is configured as a brake pedal. For example, one of the actuating devices 2 is configured as a direction selector switch. Each actuating device 2 has a signal interface that is connected to a signal interface on a vehicle control unit 7. The vehicle control unit 7 is configured to control drive train functions 9 according to the manual user inputs.The drive train functions 9 act on a braking device 3, a drive motor 4 and / or a gearbox 5 of the working machine 1, which are shown here in a highly schematic summary. The data flow is visualized by the dashed arrows.

[0027] Furthermore, the drive system 1 comprises an environmental monitoring system 6 with a signal interface and a user support interface 8, which is connected to the signal interface of the environmental monitoring system 6 for signal transmission. The user support interface 8 is configured to control the drivetrain functions 9, independently of the vehicle control unit 7 and in accordance with the environmental monitoring system 6, in order to assist the user in operating the machine 1. For example, a deceleration of the machine 1 to avoid collisions is provided as a drivetrain function 9. For this purpose, the drivetrain function 9 can act on the braking device 3, the drive motor 4 and / or the transmission 5 of the machine 1.In the present case, the user support interface 8 is integrated into a control unit 10, which is intended, for example, to control the transmission 5 or the brake device 3.

[0028] According to the block diagram, manual user inputs at the actuators 2 are first transmitted to the vehicle control unit 7 and evaluated there before they can be used to control powertrain functions 9. In contrast, the environmental monitoring signals generated by the environmental monitoring system 6 are separated from the signals of the vehicle control unit 7 and provided on a second signal path at the user support interface 8 in order to control the powertrain functions 9 via this second signal path. Thus, there is a separation between the control of the powertrain functions 9 by means of the respective actuator 2, which can be understood as a human-machine interface, via the vehicle control unit 7, and the user support interface 8, which receives signals from the environmental monitoring system 7 directly, i.e., without detours via the vehicle control unit 7.Separating the signal paths reduces the latency for controlling the powertrain functions 9 via the user support interface 8, since the vehicle control unit 7 is not interposed. Furthermore, different control options for the powertrain functions 9 are created because a second signal path is generated via the user support interface 8. For example, in a critical situation triggered by the environmental monitoring system 6, a deceleration of the work machine 1 can be initiated immediately by all means, regardless of the ferry operation.For example, data signals for decelerating the driven machine 1 are provided via the user support interface 8, in particular data signals for reducing the speed and / or torque of the drive motor 4, data signals for changing a gear ratio, and data signals for increasing the braking torque of the brake device 3. The user support interface 8 can optionally be configured for bidirectional communication with the environmental monitoring system 6 in order to adapt environmental monitoring areas, for example, to the speed of the driven machine 1. ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27.

[0029] Fig. 2 shows the work machine 1, designed as a wheel loader, with the drive system according to Fig. 1, to which reference is made. The wheel loader is a construction machine for loading and transporting goods, especially bulk materials, in a bucket 11 over short distances. An operator (not shown) sits, for example, in a driver's cab 12 and operates the vehicle via several control devices 2. For user support, the wheel loader is equipped with the environmental monitoring system 6, which in this case monitors an area 14 of the vehicle's surroundings, in particular the roadway 13 in the direction of forward travel, by means of imaging sensors, radar sensors, and / or LiDAR sensors. In particular, a plurality of these sensors can be arranged on the vehicle to monitor part or all of the surroundings, especially also in the direction of reverse travel and / or laterally.During ferry operation, the user controls the vehicle through user inputs, with the control signals acting on the braking system 3, the drive motor 4, and the transmission 5 via the vehicle control unit 7 and the powertrain functions 9. Furthermore, the powertrain functions 9 can be controlled, particularly in the event of an impending collision with an object, via the environmental monitoring signals generated by the environmental monitoring system 6, which are provided at the user support interface 8.

[0030] ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27

[0031] Reference mark

[0032] 1 working machine

[0033] 2 Actuating device

[0034] 3. Braking system

[0035] 4 Drive motor

[0036] 5 gearboxes

[0037] 6 Environmental monitoring system

[0038] 7 Vehicle control unit

[0039] 8 User Support Interface

[0040] 9 Powertrain functions

[0041] 10 Control unit

[0042] 11 shovel

[0043] 12 driver's cab

[0044] 13 lanes

[0045] 14 area

Claims

ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27 Patent claims 1. Drive system for a drive train of a working machine (1) comprising • several actuating devices (2) for manual user input, each actuating device (2) having a signal interface, • a braking device (3), a drive motor (4) and a gearbox (5) with a respective signal interface, • an environmental monitoring system (6) with a signal interface, • a vehicle control unit (7) with at least one signal interface which is connected to the signal interface on the respective actuating device (21 , 22, 23) for signal transmission and is configured to control powertrain functions (9) according to the manual user inputs, and • a user support interface (8) which is connected to the signal interface of the environmental monitoring system (6) for signal transmission and is configured to control powertrain functions (9) in accordance with the environmental monitoring system (6) and separately from the vehicle control unit (7).

2. Drive system according to claim 1, wherein the environmental monitoring system (6) comprises an imaging sensor, a radar sensor and / or a LIDAR sensor.

3. Drive system according to one of the preceding claims, wherein the user support interface (8) is integrated into a control unit (10) of the transmission (5) or the braking device (3).

4. Method for operating a drive system according to one of the preceding claims, wherein manual user inputs are first evaluated by the vehicle control unit (7) and then used to control powertrain functions (9), wherein environmental monitoring signals are provided separately from the signals of the vehicle control unit (7) at the user support interface (8) to control the powertrain functions (9). ZF Friedrichshafen AG File 303465 Friedrichshafen 2024-11-27 5. Method according to claim 4, wherein the user support interface (8) provides data signals for changing a speed and / or torque of the drive motor (4).

6. Method according to claim 4 or 5, wherein the user support interface (8) provides data signals for changing a gear ratio.

7. Method according to any one of claims 4 to 6, wherein the user support interface (8) provides data signals for changing a braking torque of the braking device (3).

8. Method according to any one of claims 4 to 7, wherein the user support interface (8) provides data signals for delaying the working machine (10).

9. Method according to any one of claims 4 to 8, wherein the user support interface (8) is set up for bidirectional communication with the environmental monitoring system (6) and defines areas of environmental monitoring.

10. Vehicle comprising a drive system according to any one of claims 1 to 3.

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