METHOD FOR CARRYING OUT A TOWING PROCEDURE AND CORRESPONDENT MOTOR VEHICLE.

Description

[0001] The invention relates to a method for carrying out a towing operation and a corresponding motor vehicle.

[0002] Nowadays, driver assistance systems have become an indispensable part of motor vehicles. Driver assistance systems have functions that support the driver while driving. In addition to increasing road safety, the main aim of such systems is to increase comfort and relieve the driver's workload. This is achieved in particular by the system detecting or recording the surroundings, processing the detected information and then carrying out appropriate driving maneuvers or clearly displaying the surrounding information to the driver. Cameras that record at least part of the area around the vehicle are used for this purpose. Well-known examples are front cameras that are located near the windshield and record the area in front of the vehicle. Rear-view cameras are also state of the art. These record the area behind the vehicle when reversing.

[0003] Even though vehicles are becoming increasingly more sophisticated and advanced in terms of technology, it can still happen that a vehicle breaks down and then needs to be towed. In addition to the use of tow trucks, towing is also frequently carried out by private individuals. This means, in particular, that a normal vehicle is used as the towing vehicle and tows the vehicle being towed using a cable. Because towing is not an everyday scenario, the driver of the towing vehicle is often overwhelmed by the situation, making it easy to make mistakes and subsequently dangerous situations. Particularly when the cable is under tension, resulting in a strong jerk, the driver of the towing vehicle may make uncontrolled steering and / or braking interventions that could endanger traffic.

[0004] US 2015 / 239436 A1 describes a method for performing a towing operation of an autonomously moving first vehicle, which tows an autonomously moving second vehicle when the second vehicle has a specific defect and has consequently been stopped or parked. In this state, the wheels of the second vehicle are locked via a wheel locking unit. To perform the towing operation, a front surface of the second vehicle is first detected using a camera of the first vehicle. Based on this, the first vehicle is positioned at a distance in front of the second vehicle and oriented in the same direction as the second vehicle.The first vehicle is then moved backward toward the front of the second vehicle, and a towing device located at the rear of the first vehicle is extended and connected to a tow bar of the second vehicle. In this connected state, the first vehicle is moved forward, exerting a pulling force on the tow bar. Upon reaching a certain pulling force, a special connection mechanism deactivates the wheel locking unit, and the second vehicle is moved forward by the first vehicle.

[0005] US 2017 / 235307 A1 also describes a method for performing a towing operation of a first vehicle. If it is determined that the first vehicle is in a state of towing an object, the maximum speed of the first vehicle is set to a value that is lower than the maximum speed when the first vehicle is not in a towing state. To determine whether the first vehicle is in a towing state, the first vehicle has a towing detection sensor, which can be embodied as a sound wave sensor, an infrared sensor, and a camera, and which is mounted near a trunk lid or a rear window to detect a towed object behind the first vehicle.The towing detection sensor may also be mounted on a connecting device, such as a trailer hitch having elements such as a towing device and a coupling ball, intended for towing the object and may thereby detect the towed object behind the vehicle in response to the object being connected to the connecting device.

[0006] DE 202 07 743 U1 describes a towing device for a vehicle, with an optical measuring system integrated into the chassis of the vehicle that determines the distance to another vehicle involved in the towing process. The measuring system can, for example, consist of a transmitter and a detector, with the transmitter emitting an optical signal that is reflected by the other vehicle and then picked up again by the detector. The measuring system can be arranged at the rear of the (towing) vehicle. If the measurement shows that the distance is decreasing, it can be concluded that the element connecting the two vehicles is no longer under tension and there is a risk of rolling away. Conversely, if the distance increases, the tension can become too great and the contact between the vehicles may be lost. Depending on the measured data, the braking system of one of the two vehicles is therefore acted upon.

[0007] DE 102 97 674 T5 describes a method for operating a vehicle control system of a vehicle that can control a number of controllable vehicle subsystems depending on preset vehicle operating modes. A current operating state is detected using at least one sensor, and access to at least one of the preset operating modes is restricted in response to an output value of the at least one sensor. Also mentioned as such a sensor is a towing sensor, which is configured to detect when the vehicle is being used to pull a trailer and the like, and which outputs a response signal to a central control unit of the vehicle control system, for example, in response to the force acting on a trailer coupling when a removable trailer coupling is arranged in position, when a trailer is electrically connected to the vehicle, and the like.For example, a sport mode cannot be selected if the tow sensor indicates that a trailer or similar is attached to the tow bar.

[0008] DE 10 2014 213 050 A1 describes a mobile device for providing energy to a motor vehicle, wherein the device comprises a charging interface device designed to provide high-voltage energy to the motor vehicle by means of an energy transfer. Furthermore, the device comprises a communication interface device coupled to the charging interface device and designed to exchange data with the motor vehicle. The charging interface device can be used to transmit electrical energy from another motor vehicle to the motor vehicle to be charged, having a power transfer cable. In this case, sagging of the power transfer cable can be detected by means of a camera, and the distance can be regulated based on the detected sagging.

[0009] DE 10 2018 000 029 A1 describes a method for restricting the operation of a towing vehicle depending on the restrictions associated with a towed vehicle. For example, if the towed vehicle is an electrified vehicle, a towing assistance system can restrict the operation of the towing vehicle by issuing control signals to the towing vehicle that limit the maximum speed of the towing vehicle while towing the towed vehicle. Furthermore, certain actions are coordinated between the towing vehicle and the towed vehicle, for example, transmitting captured images from a rear-facing camera of the towed vehicle to the towing vehicle and vice versa.

[0010] Based on this, it is now the object of the invention to provide the driver of a towing vehicle with an assistance function during a towing operation so that the towing operation can be carried out safely and in a controlled manner and the situation does not become even more difficult.

[0011] The problem is solved by the subject matter of the independent claims.

[0012] The advantage here is that the towing process takes place in a controlled and prudent manner, as the handling and operation of the towing vehicle is automatically adapted to the current, usually unfamiliar, situation.

[0013] The towing speed can be a fixed speed. However, it is also possible for the towing vehicle driver to individually adjust the towing speed. This has the advantage that towing vehicle drivers who have towed several times can enter a higher towing speed, which inexperienced drivers can then set to a lower value. It is advantageous if a maximum towing speed, which must not be exceeded during towing mode, is specified and, in particular, cannot be changed.

[0014] The towing speed can be adjusted, in particular, by comparing the speed of the towing vehicle at the time the towing mode is activated with the towing speed. If the vehicle speed is faster than the towing speed, the speed at which the towing vehicle can move forward is throttled to the predefined value. If the speed is below the towing speed, the current speed is maintained. It is also possible for the speed to be increased to the towing speed. This occurs, in particular, if the towing vehicle driver is informed of this in advance.

[0015] The activation of towing mode can be communicated to the towing vehicle driver. This can be done both visually and acoustically.

[0016] Towing mode is activated by using a camera to capture the area behind the vehicle. The camera is a rearview camera. The camera captures the area behind the vehicle, generates image data, and detects at least one towing vehicle in the image data.

[0017] The towing device is a tow rope. The tow rope is preferably flexible or bendable, so that it can be slackened or sagging, but can also be tensioned.

[0018] The towing device detected to activate the towing mode is a slack and / or untightened and / or movable tow rope.

[0019] It is also fundamentally possible for towing mode to be activated by pressing a hazard warning button in the towing vehicle, particularly in combination with at least one other indicator for towing mode. It is also conceivable for towing mode to be activated via Car2Car communication by one of the participating vehicles.

[0020] It's advantageous if the towing mode is activated automatically, meaning no action is required from the towing vehicle driver.

[0021] In a preferred embodiment, the towing mode is automatically terminated. This occurs, in particular, when a taut tow rope is detected in the image data and / or when a predefined tensile force is detected that is present on the towing device or tow rope.

[0022] Preferably, the towing speed is canceled after the towing mode ends. After the towing mode ends, the towing vehicle driver can then generally drive the towing vehicle at a desired speed.

[0023] It is advantageous if the towing vehicle driver is informed of the status of the towing vehicle during the towing operation, or at least while the towing mode is active. This can be achieved, in particular, by displaying the area captured by the camera, in particular at least one captured area that includes the towing vehicle, on a display device at the latest upon activation of the towing mode. The display remains at least until the towing mode is ended, preferably until the end of the towing operation.

[0024] According to a second aspect, the invention relates to a motor vehicle according to claim 4.

[0025] The motor vehicle according to the invention has the advantage of enabling the most comfortable and safe towing possible. This allows the driver of the towing vehicle to be reliably informed of the position of the towing vehicle during a towing operation, thus avoiding unpleasant surprises.

[0026] The condition of the tow rope is detected and evaluated by the image processing device. The image processing device is configured to detect a slack and / or moving tow rope, thereby activating towing mode, and / or to detect a tensioned and / or taut tow rope, thereby terminating towing mode.

[0027] The camera is a rear-view camera. This expands the functionality of the rear-view cameras known from the prior art. As the name suggests, the known rear-view cameras are currently only used or are active when a vehicle is reversing, in particular at a speed below a threshold. If a vehicle is moving forward, they are not active. In the camera system according to the invention, the rear-view camera is now also active, at least temporarily, when the towing vehicle is moving forward and records an area behind the vehicle. It is conceivable that the rear-view camera only becomes active when a towing operation is also taking place when the vehicle is being towed. In principle, the existence of a towing operation can be detected automatically, for example by a force being exerted on a tow hook of the motor vehicle.It is also conceivable that the rear view camera is generally active all the time, for example, it remains in a so-called twilight sleep, but only records the surroundings when driving forward and a towing operation is taking place.

[0028] The camera system preferably has at least one display device. This allows the image captured by the camera, in particular the current position or state of the towing device, to be displayed to the towing vehicle driver. The towing vehicle driver is thus no longer surprised by the jerking load associated with the tightening of the tow rope, thus preventing misconduct.

[0029] In a preferred embodiment, the camera system comprises a control unit. The control unit is configured such that, upon detection of a towing device and, in particular, activation of a towing mode, it aligns the vehicle speed with a towing speed, i.e., regulates the vehicle speed, in particular, to a towing speed. The towing speed can be stored in the system or in a memory unit. It is also possible for the towing speed to be individually adjusted by the towing vehicle driver. It is advantageous if the system predetermines a maximum towing speed that cannot be exceeded, even by an individual input.

[0030] The control unit is preferably configured to compare, in particular, the vehicle speed prevailing at the time the towing mode is activated with the towing speed. If the vehicle speed is greater than the towing speed, i.e., the towing vehicle is moving faster than it should in towing mode, the control unit reduces the speed to the predefined value.

[0031] Furthermore, the control unit can be designed such that it cancels the towing speed after the towing mode has ended, allowing the driver to freely select or adjust the speed. The towing vehicle can then be driven again at a speed specified by the driver.

[0032] In a preferred embodiment, the camera system includes a force sensor for measuring the tensile force in the towing device. This allows the tensile force acting on the tow rope to be detected.

[0033] Further advantageous embodiments are shown in the drawings. Fig. 1: a schematic representation of a towing situation; Fig. 2: a schematic representation of a flowchart of a method according to the invention in one embodiment; Fig. 3: a schematic representation of a speed curve of a towing vehicle during a towing operation in one embodiment; Fig. 4: a schematic representation of a camera system according to the invention in one embodiment.

[0034] Figure 1shows a schematic representation of a towing situation. It shows a towing vehicle 10 towing another vehicle 22 using a towing device 14 designed as a tow rope. A camera system 100 with a camera 12 is arranged on the towing vehicle 10. The condition of the tow rope can be detected and evaluated by the camera system 100. Depending on the evaluation of the condition of the towing device 14, a towing mode is activated and / or deactivated or ended. The camera 12 is a rearview camera, which is at least temporarily active even when the towing vehicle 10 is moving forward and records an area behind the vehicle 10.

[0035] Figure 2shows a schematic representation of a flowchart of a method according to the invention for performing a towing operation in one embodiment. In a first step S1, a towing mode is activated. Activation occurs with the aid of a camera 12, wherein an area located behind the vehicle 10 is captured by the camera 12, image data is generated, and at least one towing device 14, more precisely a slack tow rope, is detected in the image data.

[0036] If the towing mode has been activated, then in a further step S2, the vehicle speed is adjusted to a towing speed. The towing speed is, in particular, a fixed speed. The adjustment of the towing speed can be carried out, in particular, by comparing the speed traveled by the towing vehicle 10 at the time of activation of the towing mode with the towing speed. If the vehicle speed is faster than the towing speed, then the speed at which the towing vehicle 10 can move from now on is throttled to the predefined value. This is done in Figure 3 shown in more detail.

[0037] In a further step S3, the towing mode can be automatically terminated. This occurs, in particular, if a taut tow rope is detected in the image data and / or if a predefined tensile force is detected on the towing device or tow rope. After the towing mode has ended, the towing speed can be canceled, and the towing vehicle driver can freely decide on the speed to be driven.

[0038] Figure 3shows a schematic representation of a speed curve of a towing vehicle 10 during a towing operation in one embodiment. At a time t 1 , a towing mode is activated. The speed of the towing vehicle 10 is above a predefined towing speed. Consequently, the speed is throttled until a towing speed is reached. After the towing module is completed, which occurs at time t 2 , the towing speed is canceled again, and the towing vehicle driver can again determine his own driving speed.

[0039] Figure 4shows a schematic representation of a camera system 100 according to the invention for detecting a towing operation in one embodiment. The camera system 100 comprises at least one camera 12 arranged at the rear of a vehicle, more precisely a rear-view camera, for capturing at least a partial area located behind the vehicle 10. The camera system 100 further comprises an image processing device 16, which is designed to detect a towing device 14 in the captured image data, whereby a towing mode can be activated and / or terminated. The camera system also comprises a control unit 18, which is designed to align a vehicle speed with a towing speed after detecting a towing device 14. In order to be able to determine a tractive force prevailing in the towing device 14, the camera system 100 can also comprise a force sensor 20.

[0040] The invention has been described above using exemplary embodiments. It is understood that numerous modifications and variations are possible without departing from the scope of protection defined by the patent claims. Combinations of the various exemplary embodiments are also possible. List of reference symbols

[0041] 10Towing vehicle 12Camera 14Towing equipment 16Image processing device 18Control unit 20Force sensor 22Vehicle to be towed 100Camera system S1 - S3Procedure steps

Claims

1. Method for carrying out a towing operation by a towing vehicle (10) comprising the following steps: a) activating a towing mode (S1), wherein the towing mode is activated with the assistance of a reversing camera (12) for sensing an area behind the towing vehicle (10), wherein the following steps are carried out: - sensing the area behind the towing vehicle (10) by means of the reversing camera (12), - generating image data, - detecting a slack or moving towing rope in the image data, - activating the towing mode when a slack and / or moving towing rope is detected, b) adapting a vehicle speed to a towing speed (S2).

2. Method according to Claim 1, characterized in that the towing mode is ended (S3) when at least one of the following events happens: - a tensioned or taut towing rope is detected in the image data or - a predefined tractive force on the towing rope is detected.

3. Method according to either of Claims 1 and 2, characterized in that, after ending of the towing mode, the towing speed is suspended and the driver of the towing vehicle can preferably drive the towing vehicle (10) again at a driving speed desired by the driver.

4. Motor vehicle (10) having a camera system (100) for detecting a towing operation, having at least one reversing camera (12), which is arranged on the rear of a vehicle and is intended for sensing at least a partial area behind the vehicle (10); an image processing device (16), which is designed such that a slack and / or moving towing rope is detected in the sensed image data, whereby a towing mode is activated; a control unit (18), which is designed in such a way that, after detection of a slack and / or moving towing rope by the image processing device (16), a vehicle speed is adjusted to a towing speed.

5. Motor vehicle according to Claim 4, characterized by a force sensor (20) for measuring a tractive force in the towing rope.