Method for braking a train

Abstract

The disclosure relates to a method for braking a tractor-trailer combination (2) consisting of a tractor unit (4) and a braked trailer (16). The tractor unit (4) has an electric traction motor (6) for driving the tractor unit (4). The method comprises decelerating (S2) the tractor unit (4) by operating the electric traction motor (6) in generator mode. The method also comprises transmitting (S4) an electronic brake signal related to the deceleration of the tractor unit (4) to the braked trailer (16). The method further comprises braking (S5) the trailer (16) by means of a trailer brake (18) based on the transmitted electronic brake signal.

Description

Technical field

[0001] The present disclosure relates to a method for braking a tractor-trailer combination. The present disclosure also relates to a control device for decelerating a tractor unit, as well as to a control device for braking a trailer. The present disclosure further relates to a vehicle with such a control device. State of the art

[0002] Trailers typically have an overrun device. When the towing vehicle brakes, the trailer runs into the towing vehicle. The overrun device is designed to cause the trailer to brake. DE 10 2018 211 579 A1 relates to a method for braking a vehicle. DE 10 2020 201 901 A1 relates to a brake control device for a vehicle combination and a method for controlling the brakes of a vehicle combination.

[0003] DE 10 2023 109 706 A1 relates to an optimization of the integrated trailer brake control for vehicles. DE 10 2018 204 391 A1 relates to a power control device for controlling an electric motor in a trailer. Description of the invention

[0004] A first aspect of the present disclosure relates to a method for braking a vehicle combination consisting of a tractor unit and a braked trailer. The tractor unit can comprise a vehicle designed to pull another vehicle, thus forming a vehicle combination. The tractor unit can be, for example, a work machine such as construction or agricultural machinery, such as a tractor or a wheel loader. The braked trailer can be a vehicle equipped with trailer brakes and designed to be pulled by the tractor unit. The trailer brakes can be hydraulic and, alternatively or additionally, pneumatic. Alternatively or additionally, the trailer brakes can be electrically operated. The trailer can be designed to transport goods. The tractor unit has an electric traction motor for powering the tractor unit.The electric traction machine can be configured to transmit power to the wheels of the tractor in order to drive them.

[0005] The method involves decelerating the tractor by operating the electric traction motor in generator mode. Deceleration can be equivalent to braking. The electric traction motor can operate in motor mode or generator mode. In motor mode, the electric traction motor converts electrical power into mechanical power, which it uses to drive the tractor. In generator mode, the electric traction motor operates as a generator, converting mechanical power into electrical power. Furthermore, in generator mode, the electric traction motor can provide a braking torque that decelerates the tractor. Operating the electric traction motor in generator mode enables wear-free or low-wear braking, for example, regenerative braking.

[0006] The method involves transmitting an electronic brake signal, related to the deceleration of the tractor unit, to the braked trailer. This transmission can occur via a wired connection or, alternatively or additionally, via wireless data transmission. For example, transmission can occur via a CAN bus or another wired connection. Transmission can also occur via Bluetooth, Wi-Fi, NFC, or another suitable wireless connection. "Related" can include the electronic brake signal being transmitted depending on the deceleration of the tractor unit. Alternatively or additionally, the brake signal can be transmitted when deceleration of the tractor unit is desired. The amplitude of the electronic brake signal can also correlate with the deceleration.The procedure involves braking the trailer using the trailer brakes based on the transmitted electronic brake signal. The electronic brake signal can include a control command for the trailer brakes. The electronic brake signal can also include speed information, based on which a control unit can activate the trailer brakes.

[0007] The described method can increase safety when driving a tractor-trailer combination where the tractor unit uses regenerative braking. By transmitting the electronic brake signal to the trailer brakes, the trailer can be braked in accordance with the deceleration of the tractor unit, thus preventing the tractor-trailer combination from jackknifing.

[0008] Transmitting the electronic brake signal involves sending a stronger electronic brake signal when the tractor unit decelerates more sharply. This stronger electronic brake signal can trigger a stronger braking response. For example, when the tractor unit decelerates more sharply, the electronic brake signal can cause the trailer to brake more sharply. The tractor unit's deceleration can be detected by suitable sensors, such as speed or rotational speed sensors. Alternatively or additionally, the tractor unit's deceleration can be estimated or modeled, for example, using a mathematical model. Transmitting a stronger electronic brake signal when the tractor unit decelerates more sharply further enhances the advantages already described.This means, for example, that a collision between the tractor unit and the towed trailer can be avoided if the tractor unit decelerates sharply. Furthermore, handling can also be improved by coordinating the trailer's braking with the tractor unit's deceleration.

[0009] The transmission process involves sending an electronic braking signal that causes the trailer to brake more strongly than the tractor unit decelerates when operating in generator mode. This means the trailer experiences a greater deceleration than the tractor unit. The process may involve sensing or estimating the relevant decelerations to provide the appropriate braking signal. For example, the tractor unit's deceleration can be estimated by a control unit and this estimate transmitted to a control unit in the trailer. Based on this, the trailer control unit can operate the trailer brakes so that the trailer brakes more strongly than the tractor unit. The braking process may involve control and, alternatively or additionally, regulation, for example, based on sensed speed data of the vehicle combination.The stronger braking system provided by the trailer allows the tractor-trailer combination to remain taut during braking. This prevents a collision between the tractor and the trailer. It also effectively prevents the tractor-trailer combination from jackknifing.

[0010] In one embodiment, the method involves determining the position of the tractor's accelerator pedal, with the tractor decelerating based on this determined position. The accelerator pedal can be configured to indicate a target speed for the tractor or tractor-trailer combination. A position can correspond to a target speed. For example, pressing the accelerator pedal further can correspond to a higher target speed. The position can be detected by a suitable sensor. The tractor can decelerate if the current speed is higher than the target speed corresponding to the accelerator pedal position. It can also accelerate if the current speed is lower than the target speed corresponding to the accelerator pedal position.The described deceleration based on the accelerator pedal position provides a method for effectively braking the vehicle combination without using a brake pedal. This reduces the driver's workload, as they only need to operate the accelerator pedal to brake safely and effectively.

[0011] In one embodiment, the method involves feeding the energy generated by the electric traction motor into an energy storage device of the tractor-trailer combination. The energy storage device can be located in the tractor unit. Alternatively or additionally, the energy storage device can also be located in the trailer. The energy storage device can include a battery, for example, a lithium-ion battery. The energy storage device can also include a capacitor. The electric traction motor can be electrically connected to the energy storage device. The energy storage device can be configured to supply electrical energy to the electric traction motor when it is operating in motor mode. Alternatively or additionally, the energy storage device can be configured to supply electrical energy to another component of the working machine.By feeding the energy generated during deceleration back into the system, a particularly efficient method for braking a train is provided. The energy used to propel the train can be recovered and reused through this method. This enables a particularly environmentally friendly and, alternatively or additionally, cost-effective braking system.

[0012] In one embodiment, the method involves activating at least one brake light of the tractor-trailer combination depending on at least one of the deceleration of the tractor unit and the braking of the trailer. The tractor unit may have a brake light. The brake light of the tractor unit may be located at the rear, i.e., on a side opposite to the normal direction of travel. The trailer may have a brake light. The brake light of the trailer may be located at the rear, i.e., on a side opposite to the normal direction of travel. The brake light may be red. Activation may include illuminating, energizing, driving, or other steps. Activation can be performed when deceleration of the tractor unit occurs or is detected. Alternatively or additionally, activation can occur when braking of the trailer occurs or is detected.Activating the brake lights increases the visibility of the vehicle combination and clearly indicates deceleration or braking of the trailer. This improves safety when driving the vehicle combination.

[0013] Braking a braked trailer involves applying pressure to the trailer brakes. This application can be done with compressed air, for example, if the trailer brakes are pneumatic. It can also be done with hydraulic fluid, for example, if the trailer brakes are hydraulic. The trailer brakes can be supplied with compressed air or fluid from the tractor unit. Alternatively or additionally, the trailer brakes can also be supplied with compressed air or fluid from the trailer itself. The application of pressure to the trailer brakes can be proportional to the deceleration of the tractor unit. Applying pressure to the trailer brakes provides a method that is both highly efficient due to the deceleration provided by the electric traction motor and particularly simple due to the application of pressure to the trailer brakes.Existing train sets can be more easily adapted to implement the described procedure. Furthermore, pressure-based braking can offer a high degree of reliability.

[0014] A second aspect of the present disclosure relates to a control device for decelerating a tractor, wherein the tractor has an electric traction motor for driving the tractor. The control device is configured to transmit an electronic brake signal related to the deceleration of the tractor to an attached trailer in order to carry out a method according to the first aspect. Further features, embodiments, and advantages are described in the first aspect. Conversely, features, embodiments, and advantages of the second aspect also represent features, embodiments, and advantages of the first aspect. The control device may be arranged in or on the tractor. The control device may have one or more interfaces for communicating with the various components of the tractor.The control unit can, for example, be configured to communicate via a CAN bus. It can be configured to communicate with the electric traction motor, a brake on the tractor unit, a brake light, and alternatively or additionally with other components. The control unit can be configured to communicate with a control unit on the attached trailer to transmit the electronic brake signal. The tractor unit's control unit and the trailer's control unit can operate in a master-slave relationship. Accordingly, the tractor unit's control unit can be configured to transmit a command, and the trailer's control unit can be configured to execute it.

[0015] A third aspect of the present disclosure relates to a control device for braking a trailer equipped with a trailer brake. The control device is configured to receive an electronic brake signal and, based on the received electronic brake signal, to brake the trailer using its trailer brake in order to perform a method according to the first aspect. Further features, embodiments, and advantages of each aspect are described in the first and second aspects. Conversely, features, embodiments, and advantages of the third aspect also represent features, embodiments, and advantages of the first and second aspects. The control device may be located in or on the trailer. The control device may have one or more interfaces for communicating with the various components of the trailer.It can be configured to communicate with the trailer brake, a brake light, a tractor unit's control unit, and alternatively or additionally with other components. The control unit can be configured to communicate with a tractor unit's control unit to receive the electronic brake signal.

[0016] Furthermore, the present disclosure relates to a control system comprising a control device according to the second aspect and a control device according to the third aspect, which is configured to execute a method according to one of the embodiments described above.

[0017] A fourth aspect of the present disclosure relates to a vehicle with at least one of the control devices according to the second or third aspect or the control system described above. Further features, embodiments, and advantages are described in the first, second, and third aspects. The vehicle may be a tractor unit with a braked trailer, a tractor unit alone, or a trailer alone. Brief description of the characters Fig. Figure 1 schematically illustrates a tractor unit with a tractor and a braked trailer according to an embodiment of the present disclosure. Fig. Figure 2 shows a flowchart of a procedure for braking the train. Fig. 1 according to one embodiment of the present disclosure. Detailed description of embodiments

[0018] Fig. Figure 1 schematically illustrates a tractor-trailer combination 2 with a tractor unit 4 and a braked trailer 16 according to an embodiment of the present disclosure. The tractor unit 4 is a tractor which is mechanically coupled to the trailer 16 via the connection 24 and pulls it. The tractor unit 4 has an electric traction motor 6 which is configured to drive the tractor unit 4. For this purpose, it is mechanically coupled to wheels of the tractor unit 4 (not shown). The electric traction motor 6 can be operated in motor mode and in generator mode. In motor mode, the electric traction motor 6 can generate mechanical power to drive the tractor unit 4 and the tractor-trailer combination 2.

[0019] In generator mode, the electric traction machine 6 can convert mechanical power into electrical energy. For example, if the tractor 4 is moving and the electric traction machine 6 is operating in generator mode, it can convert the kinetic energy of the tractor 4 into electrical energy. In doing so, the electric traction machine 6 generates a corresponding braking torque, which decelerates the tractor 4, thus providing regenerative braking. The electric traction machine 6 is also connected to an energy storage device 8. In generator mode, the electric traction machine 6 can feed the generated electrical energy into the storage device, and in motor mode, it can draw energy from it.

[0020] The tractor 4 has an accelerator pedal 10, which the driver uses to set a speed for the tractor 4. Each position of the accelerator pedal 10 corresponds to a specific driving speed, with further depression of the accelerator pedal 10 corresponding to a higher speed. When the accelerator pedal 10 is released or depressed less, the tractor 4 decelerates until it reaches the desired driving speed. The tractor 4 can also use regenerative braking with its electric traction motor 6 to achieve the desired reduced driving speed. The corresponding braking characteristic is adjustable and can be set via a control unit 14 on the tractor 4. For example, the braking characteristic can be set to light, medium, or strong, causing the tractor 4 to decelerate lightly, moderately, or strongly, respectively, when braking.The tractor unit 4 also has a brake light 12, which illuminates when the tractor unit 4 brakes or decelerates. The brake light 12 is located on the side of the tractor unit 4 facing away from the direction of travel, i.e., on the rear side.

[0021] The trailer 16 has a trailer brake 18, which in the illustrated embodiment is a compressed air brake. Compressed air for operating the compressed air brake is transmitted from the tractor 4 to the trailer 16 via the connection 24. The trailer brake 18 is operated by a control unit 20 of the trailer 16. The trailer brake 18 is designed to decelerate or brake the trailer 16. According to the Fig. In the method shown in Figure 2, the trailer 16 decelerates more strongly than the tractor unit 4 when braking. Thus, the entire tractor unit 2 remains under tension even during braking, and a collision between the tractor unit 4 and the trailer 16 or buckling is avoided. The trailer 16 has a brake light 22, which illuminates when the trailer 16 brakes or decelerates. The brake light 12 is located on the side of the trailer 16 facing away from the direction of travel, i.e., on the rear side.

[0022] The control unit 14 of the tractor 4 is electronically connected to the electric traction motor 6, the accelerator pedal 10, and the brake light 12. The control unit 14 is also connected to sensors (not shown) to determine the driving speed of the tractor 4. The control unit 14 of the tractor 4 is configured, together with the control unit 20 of the trailer 16, to control the Fig. The control unit 14 is configured to detect the position of the accelerator pedal 10 and, based on this, to set a driving speed for the tractor 4. The control unit 14 is also configured to operate the electric traction motor 6, for example, to switch between motor and generator operation and to set a rotational speed and power. The control unit 14 is also configured to activate the brake light 12 when the tractor 4 brakes or decelerates. The control unit 20 of the trailer 16 is connected to the trailer brake 18 and to the brake light 22 and is configured to activate the brake light 22 when the trailer 16 brakes or decelerates. The control unit 20 is connected to the control unit 14 of the tractor 4.It is designed to receive a braking request and deceleration from the tractor unit 4 and, depending on this, to actuate the trailer brake 18 and the brake light 22.

[0023] Fig. Figure 2 shows a flowchart of a procedure for braking the train set 2 from Fig.1 according to an embodiment of the present disclosure. The method is carried out by the control units 14 and 20. In step S1, the control unit 14 of the towing vehicle 4 determines the position of the accelerator pedal 10 of the tractor 4. The position of the accelerator pedal 10 corresponds to a desired driving speed. Based on the determined position of the accelerator pedal 10, in step S2 the tractor 4 is decelerated by the control unit 14, for example, by braking, until its speed corresponds to the set driving speed. The deceleration is carried out by operating the electric traction machine 6 in generator mode, in which the electric traction machine 6 generates a braking torque. The electric traction machine 6 thereby generates electrical energy, which is fed into the energy storage device 8 by the control unit 14 in step S3.

[0024] In step S4 of the transmission process, an electronic brake signal related to the deceleration of the tractor unit 4 is transmitted from the control unit 14 to the trailer 16. The control unit 14 of the tractor unit 4 communicates with the control unit 20 of the trailer 16 and transmits the brake signal to the control unit 20 of the trailer 16, which is configured to receive the electronic brake signal. The transmission can be wired or wireless.

[0025] The control unit 20 of the trailer 16 receives the electronic brake signal, and based on this signal, the trailer 16 is braked by the trailer brake 18 in step S5. The brake signal is designed such that it results in a stronger braking action of the trailer 16 by the trailer brake 18 than the deceleration of the tractor 4 by the electric traction motor 6. The deceleration of the tractor 4 can be determined, for example, using speed sensors and velocity sensors. Additionally or alternatively, the deceleration can also be determined using mathematical models. The braking action S5 can include a step S5.1 of applying pressure to the trailer brake 18 proportional to the deceleration of the tractor 4. In the embodiment shown here, this pressure is applied using compressed air.

[0026] In step S6 of the activation process, the brake light 12 of the tractor unit 4 is activated by control unit 14, and the brake light 22 of the trailer 16 is activated by control unit 20, depending on the deceleration of the tractor unit 4 and, alternatively or additionally, the braking of the trailer 16. These are controlled by control units 14 and 20, respectively. The activation includes illuminating the lights to indicate to other road users that the vehicle combination 2 is braking. Reference sign 2 train sets 4 tractor 6 electric traction machines 8 Energy storage 10 Accelerator pedal 12. Brake light of the tractor unit 14 Control unit of the tractor 16 trailers 18 Trailer brake 20 Trailer control unit 22. Trailer brake light 24 connection S1 Determine S2 Deceleration Tractor Unit S3 Energy feed-in S4 Transmit electronic brake signal S5 brakes trailer S5.1 Printing trailer brake S6 Activate brake light

Claims

[1] Method for braking a vehicle combination (2) with a tractor unit (4) and a braked trailer (16), wherein the tractor unit (4) has an electric traction machine (6) for driving the tractor unit (4), comprising decelerating (S2) the tractor unit (4) by operating the electric traction machine (6) in generator mode, transmitting (S4) an electronic brake signal related to the deceleration of the tractor unit (4) to the braked trailer (16), which results in braking of the trailer (16) by the trailer brake (18) that is stronger than the deceleration of the tractor unit (4) by the traction machine (6) operating in generator mode, and braking (S5) the trailer (16) by applying (S5.1) the trailer brake (18) based on the transmitted electronic brake signal. [2] Method according to claim 1, characterized by, that the transmission (S4) of the electronic brake signal includes the transmission of a stronger electronic brake signal in the event of a stronger deceleration of the tractor (2). [3] Method according to any one of the preceding claims, characterized by , that the method comprises determining (S1) a position of an accelerator pedal (10) of the tractor (4) and decelerating (S2) the tractor (4) based on the determined position of the accelerator pedal (10). [4] Method according to any one of the preceding claims, characterized by , that the method includes feeding (S3) the energy regenerated by the electric traction machine (6) into an energy storage device (8) of the train set (2). [5] Method according to any one of the preceding claims, characterized by, that the method includes an activation (S6) of at least one brake light of the towing vehicle (2) depending on at least one of the deceleration of the tractor unit (4) and the braking of the trailer (16). [6] Control device (14) for decelerating a tractor (4), wherein the tractor (4) has an electric traction machine (6) for driving the tractor (4) and wherein the control device (14) is configured to transmit an electronic brake signal related to a deceleration of the tractor (4) to an attached trailer (16) in order to carry out a method according to any of the preceding claims. [7] Control device (20) for braking a trailer (16) with a trailer brake (18), wherein the control device (20) is configured to receive an electronic brake signal from a tractor (4) and to brake the trailer (16) with its trailer brake (18) based on the received electrical brake signal in order to carry out a method according to any one of claims 1 to 5. [8] Vehicle (4; 16) with at least one of the control devices (14; 20) according to claims 6 and 7.

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