DE102017123226A1 - A method of determining a critical altitude of a forward link for a vehicle comprising a towing vehicle and a trailer - Google Patents

Abstract

The present invention relates to a method for determining a critical height of a forward track section (16) for a vehicle (10) comprising a towing vehicle (12) and a trailer (14), the method comprising the steps of:
a) providing at least one environmental sensor (28);
b) optionally detecting an obstacle (18) at a distance ahead of the vehicle (10);
c) optionally detecting the height of a track section (16) along the obstacle (18);
d) detecting the height of the vehicle trailer (14); and
e) optionally comparing the height of the vehicle trailer (14) with the height of the track section (16), characterized in that
the height of the vehicle trailer (14) is determined by the steps
d1) determining the height of the vehicle trailer (14) relative to the sensor (28);
d2) determining the absolute position of the sensor (28); and
d3) calculating the absolute height of the vehicle trailer (14) based on the result of steps d1) and d2).

Description

The present invention relates to a method of determining a critical altitude of a forward link for a vehicle that includes a towing vehicle and a trailer and a method for providing a height-related collision warning. More particularly, the present invention relates to a method that can effectively provide a collision warning according to the height of the vehicle trailer. The present invention also relates to a driver assistance system which is suitable for carrying out such a method. Furthermore, the present invention relates to a vehicle having such a driver assistance system.

Driver assistance systems in vehicles are becoming increasingly important in assisting the driver of a vehicle and reducing the risk of an accident or collision. In this regard, various systems are known which provide information about the intended route and issue collision warnings in the event of an accident being likely. For example, it is known to provide a driver assistance system that is capable of issuing a warning if the altitude on a route to be traveled is critical.

This is what the document describes US 9,269,263 B2 a vehicle proximity alarm system comprising at least one sensor or a camera arranged in a vehicle and having an external field of view in a traveling direction of the vehicle. A controller is responsive to the camera and operable to determine a height dimension of a structure in the travel path of the vehicle. The controller is operable in response to (i) the determined height dimension of a structure in the travel path of the vehicle and (ii) a height dimension of the vehicle to determine whether there is sufficient clearance between the structure and the vehicle such that the vehicle is under can drive through the structure. In response to a determination that there is insufficient clearance between the structure and the vehicle for the vehicle to pass under the structure, the alarm system is operable to generate a warning to the driver of the vehicle. With regard to determining the height of the vehicle, it is described that a height dimension of the vehicle having a load or object disposed thereon is determined by processing acquired image data and based at least in part on a known height of the vehicle in the unloaded state.

Therefore, it is essential in the prior art that the height of the vehicle is at least partially known.

The document WO2012 / 139636 A1 relates to a method for on-line calibration of a vehicle video system by evaluating image frames of a camera that include features on the road. The camera captures a section of a road surface in a picture frame. A selection is made of at least two different features within the image frame, with the selected features selected as respective reference points. An image frame sequence with at least one further image frame is taken by the camera, wherein within the new frame, the traits selected as reference points are located. In a virtual image space, the trajectory covered by the reference points is analyzed during a traveling interval in the image sequence by identifying a geometric shape obtained by connecting the localized reference points to each other in each image taking into account the respective trajectories. A deviation of the resulting geometric object from a parallelogram with vertices defined by the reference points of at least two subsequent images is calculated while any measured deviation is used to define an offset correction of the camera. However, this document is considered part of another technical field.

The prior art therefore still offers room for improvement. In particular, the prior art offers scope for improvements in providing driver assistance for determining a critical altitude of a forward route that is usable for vehicles of unknown varying altitude.

Thus, it is an object of the present invention to provide a method for determining a critical altitude of a preceding route relative to the actual altitude of the vehicle, which is easily executed and reliable in its result. Furthermore, the object of the present invention is to provide a driver assistance system suitable for carrying out such a method.

The solution of these objects is achieved according to the invention at least partially by a method for determining a critical height of a route ahead with the features of claim 1. The solution of these tasks continues to be at least partially by a driver assistance system having the features of claim 11. The solution of these tasks is also carried out at least in part by a vehicle having the features of claim 12. Advantageous embodiments of the invention are set forth in the subclaims, the further description and in the figures, wherein further embodiments or features alone or in any combination can form part of the invention, insofar as this is not the case is expressly excluded.

1. a) Bereitstellen mindestens eines Umgebungssensors;
2. b) optionales Erfassen eines Hindernisses auf einer Strecke vor dem Fahrzeug;
3. c) optionales Erfassen der Höhe eines Streckenabschnitts entlang des Hindernisses;
4. d) Erfassen der Höhe des Fahrzeuganhängers; und
5. e) optionales Vergleichen der Höhe des Fahrzeuganhängers mit der Höhe des Streckenabschnitts,

wobei
die Höhe des Fahrzeuganhängers bestimmt wird durch die Schritte

• d1) Bestimmen der Höhe des Fahrzeuganhängers relativ zum Sensor;
• d2) Bestimmen der absoluten Position des Sensors; und
• d3) Berechnen der absoluten Höhe des Fahrzeuganhängers basierend auf dem Ergebnis der Schritte d1) und d2).

The present invention provides a method of determining a critical altitude of a forward link for a vehicle having a towing vehicle and a trailer, the method comprising the steps of:

1. a) providing at least one environmental sensor;
2. b) optionally detecting an obstacle on a track in front of the vehicle;
3. c) optionally detecting the height of a link along the obstacle;
4. d) detecting the height of the vehicle trailer; and
5. e) optionally comparing the height of the vehicle trailer with the height of the route section,

in which
The height of the vehicle trailer is determined by the steps

• d1) determining the height of the vehicle trailer relative to the sensor;
• d2) determining the absolute position of the sensor; and
• d3) calculating the absolute height of the vehicle trailer based on the result of steps d1) and d2).

Such a described method provides an improved procedure for determining a critical altitude of a forward link. In particular, the method described provides a procedure that is suitable for determining a critical level of a preceding route section and that can be carried out more or less completely automatically and in real time. Furthermore, in contrast to the methods described in the prior art, it is not necessary to provide a known or estimated height of the vehicle, for example the unloaded vehicle, or parts thereof as an input value.

In detail, the method described above is used to determine a critical height of a track section lying ahead.

In this regard, a critical height of a forward track section should in particular mean a scenario in which the height of the vehicle is smaller than the height of the preceding track section according to a predetermined measure, or the height of the vehicle is equal to the height of the forward track section or the height of the vehicle is greater than the height of the next section of track. Therefore, a critical height of the route section lying ahead should in particular mean a height of the route section at which an accident or a collision with an obstacle arranged at or in the vicinity of the route section is likely or can not be ruled out.

Further, a preceding road section is a road section that is part of a route that is in front of the vehicle and thus in front of the vehicle in the direction of travel. Of course, depending on the direction of travel, and thus depending on whether the vehicle is traveling in the forward direction or in the reverse direction, the route ahead may be located in front of or in front of the rear of the vehicle.

With regard to the method for determining a critical height of a preceding track section defined above, such a method comprises the steps described below. In this case, the steps b), c) and e) are optional and therefore not absolutely necessary for the present method. Although these steps are advantageous and described as practiced, it is possible to carry out the method with the steps or without steps b), c) and e), or it is possible to carry out a part of these steps b), c) and e ) leave out. For example, only the height of the vehicle can be determined and displayed for a driver, who can then reference, for example, traffic signs indicating information about the height of the route ahead. Therefore, based on the height of the vehicle determined in accordance with the present invention and the other specified information, it may be determined whether the forward path section has a critical height with respect to the height of the vehicle.

First, and according to method step a), at least one environmental sensor is provided. Therefore, only one environmental sensor may be provided, or multiple environmental sensors may be provided, as described in detail below. The task of the at least one environmental sensor is to provide information about the sensor environment. In particular, it is the task of the at least one sensor to provide information that is for Determining the height of the vehicle and in particular the vehicle trailer and in particular other objects or obstacles is usable, which are located on a predetermined route ahead section. In general, the at least one environmental sensor may be configured as known in the art, and it is particularly preferred if at least one sensor is a camera, as described in detail below.

In this regard, and according to the optional step b), it is provided to detect an obstacle on a route section in front of the vehicle. This step, as is well known in the art, may be performed using one or more environmental sensors that sense the environment. By using a lane detection, for example, the route ahead and thus the route to be used can be detected and examined. If there is an obstacle on the trail ahead, this may be determined by the one or more environmental sensors.

In particular, an obstacle according to the present invention is intended to be any element which can influence the route along this element as it passes the route ahead. In particular, an obstacle according to the present invention is an element that allows the section to travel along the element, but the section has a limited height. An obstacle is therefore in particular an element which does not block the route as such, but which is present at least partially above the road and thus above a certain height. Non-limiting examples of such obstacles include trees, bridges, tunnels, power cables, or other elements that are at least partially over the line, such as above the road.

Therefore, passing the obstacle on the track is limited in height, which may cause problems. In detail, due to the limited height, the passage of the obstacle for vehicles may be critical depending on their height. This can be particularly critical if the height of the vehicle can vary and therefore may not be known. This may be the case, in particular, in vehicles with vehicle trailers, as the height of such trailers can often vary even during a single day or mission.

Therefore, according to an optional step c), the present method further includes detecting the height of the forward link along the obstacle. In other words, this step includes detecting the height at which the obstacle starts, and thus the height that the vehicle can use to pass the obstacle. This step can generally be carried out by methods known in the art, for example with reference to environmental detection, as described in more detail below. Therefore, in particular, each obstacle that is detected can be examined with regard to the height of the route section.

Furthermore, the present method according to step d) provides the detection of the vehicle height and thus of the vehicle trailer. This makes it possible in a later step to determine whether the vehicle can drive along with its trailer along the obstacle and thus can pass the section under the obstacle. The detection of the height of the vehicle will be described below.

In this regard, and according to optional step e), the described method may include comparing the height of the vehicle with the height of the link. This step may be performed, for example, by a control unit provided with information or data supplied by the one or more environmental sensors.

Therefore, according to this step, and in case the heights of the vehicle and the obstacle are compared, it can be judged whether there is a critical height on the preceding route. Therefore, and as stated above, it can be determined whether a scenario occurs in which the height of the vehicle is smaller than the height of the preceding road section according to a predetermined amount. In other words, in general, in the case that the height of the vehicle is smaller than the height of the preceding road section, it can be ensured that the vehicle can pass the obstacle and thus there is no danger for a collision of the vehicle with the obstacle. In this regard, it can be considered that the height of the vehicle is not generally smaller than the height of the preceding road section, but it may be smaller according to a predetermined amount. In this regard, the predetermined level may reflect some certainty, so that a particularly high level of security can be provided by taking into account a security area. The predetermined dimension and thus the security range can be defined according to the desired requirements.

Furthermore, provision may be made for the predefined value to be redefined for each detected obstacle. If, for example, the height of the Varies, it may indicate that the obstacle is, for example, a tree or a street lamp moving, for example, by the influence of strong winds. In this case, the default value can be chosen to increase the safety margin.

On the other hand, in the case that the height of the road section and thus the lower limit of the obstacle on the route is constant, this may indicate that the obstacle is, for example, a building, e.g. a tunnel or a bridge is, in which case the security area can be chosen comparatively low and the predetermined value can be selected accordingly.

According to this scenario, no collision with the obstacle is to be expected.

On the other hand, however, in the case where the height of the vehicle is only slightly smaller than the height of the preceding road section according to the predetermined amount, or if the height of the vehicle is equal to the height of the forward road section or the height of the vehicle is greater than the height of the road leading section, it is found that there is a critical height of the route ahead and therefore a collision is likely or at least can not be ruled out.

In the event that the height of the vehicle is less than the height of the forward link according to the predetermined amount, the predetermined amount may reflect a safety margin that can be defined for each obstacle, as described in detail above.

In this regard, step e) e.g. may be performed by a control unit, or it may be executed by the driver of the vehicle itself based on information, e.g. provided by traffic signs.

It thus becomes clear that the described method provides an effective collision warning with respect to obstacles that occur in particular over a distance, even if the height of the vehicle and in particular of the vehicle trailer varies. Thus, a significant safety effect can be achieved.

Therefore, according to the described method, it may be provided that, in the case that the height of the vehicle is smaller than the height of the preceding track section according to a predetermined amount, or if the height of the vehicle is equal to the height of the preceding track section, or if the altitude of the vehicle is greater than the height of the route ahead, a warning message is issued to the driver of the vehicle. Therefore, if a collision is likely, the driver of the vehicle is informed accordingly and thus is able to decelerate the vehicle to avoid the collision.

Furthermore, it may be provided in a collision warning that the collision warning is output to an emergency braking system, which may be another driver assistance system. Accordingly, the emergency brake system can automatically initiate emergency braking to avoid the collision.

In particular, according to the above, safety can be improved particularly effectively by applying the described method.

• d1) Bestimmen der Höhe des Fahrzeuganhängers relativ zum Sensor;
• d2) Bestimmen der absoluten Position des Sensors; und
• d3) Berechnen der absoluten Höhe des Fahrzeuganhängers basierend auf dem Ergebnis der Schritte d1) und d2).

In addition to the situation described above and in particular according to the described method, it is provided that the height of the vehicle trailer is determined by the steps

• d1) determining the height of the vehicle trailer relative to the sensor;
• d2) determining the absolute position of the sensor; and
• d3) calculating the absolute height of the vehicle trailer based on the result of steps d1) and d2).

These steps may be performed sequentially in a suitable range or may be performed at least partially concurrently, as will be apparent to those skilled in the art.

In particular, according to these steps, and thus in particular by determining the height of the vehicle trailer and thus the highest charge of the trailer relative to the ambient sensor used, an improved method can be realized by determining the absolute height of the sensor and then calculating the absolute height of the load or the vehicle trailer ,

In fact, using the described method, it may be provided that the height detection may be performed based on relatively simple determination steps, which may, among other things, enable processing with a comparatively low computational power. Thus, the method can be carried out by conventional control units or driver assistance systems without problems.

Furthermore, it can be provided that the method is carried out and that the height of the vehicle trailer can be determined in real time and permanently, even if the height of the vehicle trailer changes, for example due to different charges. That is, a reliable collision warning can be realized at any time, without the need for altitude data or a special altitude sensing environment. Thus, the method is particularly universal and can be suitable for a multi-purpose operation, without specific environmental requirements.

It thus becomes clear that a particularly reliable collision warning with respect to the height of a vehicle trailer can be realized. This, in turn, is an important safety feature for vehicles pulling trailers, with the amount of trailer load, for example, varying on a daily or even more frequent basis. Examples of such scenarios are agricultural, industrial or logistic scenarios. Therefore, even if the height of the trailer is not known in detail or not at all, the danger of attempting to pass an obstacle that reduces the height of the road section such as a tunnel, a bridge, a power line, etc., can is lower than the charge, excluded or at least substantially reduced. This allows a significant improvement in security.

With regard to step d), it can be advantageously provided that a step d1) is carried out by means of background subtraction in combination with the use of parallax effects and / or step d2) is carried out by means of sensor calibration or camera calibration , In particular, these embodiments can provide a method by which the advantages described above can be effectively achieved.

Regarding step d1), and particularly a background subtraction, and when the vehicle is traveling with its trailer, and particularly when the vehicle and trailer are traveling in a straight line, the trailer and cargo become static relative to the environmental sensor. Whether the vehicle and the trailer are moving in a straight line can be determined, for example, by a steering angle or trailer angle detection, as known in the art. By using the background subtraction, the area in the image in which the trailer and the cargo are located can be determined. The topmost pixel of the trailer or cargo, and thus the structure that does not move when riding in a straight line, represents the highest point of the cargo and thus the maximum altitude to be detected.

In addition, a distance of the charge and thus the determined highest pixel to the sensor should be detected in order to determine the maximum height. This may be required due to the fact that, although the highest pixel is known and thus the angle to the horizontal axis is known, the height and thus the relative height to the sensor is dependent on the distance of the pixel from the sensor. The determination of the distance of the sensor to the charge and thus the horizontal distance between the sensor and the charge and thus the maximum charge or the maximum amount of charge is possible for example by the use of the well-known parallax effects. In this case, the known horizontal distance from the sensor to the contact point of the trailer with the towing vehicle, where the trailer is rotatably connected to the tractor, can be used. This may be, for example, a known value which is stored in a driver assistance system and may, for example, include the length of the drawbar.

Therefore, when the vehicle is turning, the trailer angle detection, which is generally part of towing vehicles, will detect the angle to the axle of the towing vehicle with which the trailer has moved. Once the highest point on the trailer, and thus the highest charge, has been detected using the background subtraction described above, the amount that the pixel is moving appears to be less than the detected trailer angle. This is a known parallax effect. Then the apparent change of movement between the highest charge of the trailer 14 and the connection point to easily calculate the relative distance from the connection point of the trailer, such as from the point of the drawbar closest to the sensor, to the highest charge. It is thus easily possible to scale this to an absolute distance. It is then possible to derive the height relative to the sensor from this distance and the projected beam of the highest pixel.

Therefore, in general, the maximum height of the load can be detected, which can be projected to the correct plane by means of a camera calibration, which allows the derivation of the height of the trailer / load.

With regard to the horizontal distance from the sensor to the contact point of the trailer with the towing vehicle, this value can be entered manually or automatically determined, for example, based on the trailer angle detection. Furthermore, this value can be entered automatically when the trailer with the towing vehicle is coupled by the driver assistance system is connected to an electrical system of the trailer, in which the data of the trailer are stored.

Apart from the above and with regard to step d2), according to which the absolute position and thus the absolute height of the sensor is provided, the latter step d2) can be carried out, for example, by means of sensor calibration or camera calibration. In the following, this step will be described by way of example with reference to the camera calibration. This method allows the determination of the absolute height of the sensor, for example a camera, without using any unique known values. The use of camera calibration, therefore, allows the entire process to be applied in real-time and at any time.

With regard to the camera calibration, such a method is, inter alia, in WO 2012/139636 A1 described in more detail. Here, among other things, the height of the camera can be determined by identifying at least two feature points in at least two camera images of a vehicle that has moved between the shots of the images. The method then determines a camera translation direction between two camera positions. The method then determines a ground plane in camera coordinates based on the corresponding feature points from the images and the camera translation direction. The method then determines a height of the camera above the ground in vehicle coordinates.

Also, the speed of the moving vehicle may be used to calculate the distance of the reference points traced between frame sequences, thereby enabling the determination of the height of the camera. Therefore, the height of the camera can be determined from the ground level, for example from a road, when the speed of the vehicle is known. This is possible without any problems for the control unit via the vehicle network, for example a CAN, LIN, wireless or another network. If the speed of the vehicle is considered, the actual physical distance between the tracked features on the road surface and the sensor is known, for example, using triangulation.

As described above, using a camera calibration by the information provided, the position of the sensor, such as a camera, is displayed on the vehicle, thereby obtaining the absolute height of the sensor. However, this information alone does not indicate the information about the absolute height of the vehicle or the trailer load. Therefore, in particular, a combination of the above-described steps d2 and d3 offers the described advantages of the present invention. Specifically, the height of the load of the vehicle can be automatically calculated using a combination of background subtraction to detect the position of the trailer / load in the image and a camera calibration to determine the trailer's geometric / cargo height.

If the height of the camera is determined, the height of the charge detected relative to the camera can be calculated.

It may further be provided that the height of the route section lying ahead is determined by a three-dimensional reconstruction or 3D reconstruction. This is possible because the obstacles in the scene are static, so that when the vehicle is moving toward an obstacle, the 3D position of the obstacle in the world can be calculated, for example, using mechanical odometry of the vehicle. This is well known in the art and, for example, in the prior art document US 9,269,263 B2 described.

Specifically, the maximum height of the forward link is detected by processing front or rear sensor data sensed by forward or backward environmental sensors. Such sensor data may be detected by any suitable forward or backward sensor. The data processor may be operable to use a sensor or a portion of a sensor or a plurality of these sensors or all of these sensors through sensor combination, the data acquired by the sensors being combined for processing by the processor in a single database. Driver assistance systems are typically capable of processing sensor information to detect the size, spacing and speed of objects within the detection area in front of the vehicle being viewed or owned.

According to a further embodiment, it can be provided that the at least one environmental sensor is a single sensor that provides information both for determining the height of the road ahead section and the height of the vehicle or the load of the vehicle trailer. According to this embodiment, the provision of a single sensor may be sufficient to carry out the method according to the invention. This allows reduced costs of a driver assistance system provided for carrying out this method. In addition, will the control unit supplied only information from a sensor. This may allow a simplified calculation and may further reduce the peripherals required to carry out the method of the invention.

With respect to the sensor to be used according to this embodiment, it may be provided to use a fisheye camera or a LIDAR sensor. In particular, the above-mentioned sensors can provide a large detection angle, so that reliable information and data can be provided by using the above-mentioned sensors. This in turn allows a particularly safe process and thus reduces the risk of collision particularly reliable.

The main advantage of using a fisheye camera is its wide field of view of e.g. more than 180 °. If a fisheye camera is positioned upwardly on the roof of the vehicle, both approaching obstacles and the trailer / cargo at the rear of the vehicle could be detected, as is the case with a LIDAR sensor.

An alternative to using an environmental sensor is the use of a single sensor that provides information for both determining the height of the forward link segment and the height of the vehicle. According to a further embodiment it can be provided that at least one first environment sensor is used, which provides information for determining the height of the preceding route section and at least one second environment sensor is used, the information for determining the height of the vehicle and thus the maximum height of the charge the vehicle provides. In other words, at least two environmental sensors can be provided which can be used for different detection purposes. For detecting the height of the vehicle, therefore, a first sensor or a plurality of first sensors are provided, and for detecting the height of the obstacle, a second sensor or a plurality of second sensors is provided.

In this case, each sensor can be used and adapted to the desired requirements, whereby under certain circumstances, the inventive method can be further improved. In addition, it is often envisaged that further driver assistance systems will be provided which have additional sensors. Therefore, it can be provided that with respect to the detection of the height of the obstacle, an already provided sensor can be used. Therefore, an additional sensor for detecting the height of the vehicle can be provided. Thereby, the type of sensor used and the position of the sensor for detecting the height of the vehicle can be adjusted. This too can bring advantages in terms of the method described. This embodiment could also be used with the sensors described above, but could also be used with sensors such as optical sensors, e.g. Image sensors or cameras, infrared cameras, laser scanners / LIDAR sensors, LADAR sensors, RADAR short and wide range sensors, ultrasonic sensors and / or the like are performed.

Furthermore, in particular with regard to a vehicle pulling a trailer, it may be advantageous for the at least one environmental sensor to be arranged on the roof of the vehicle, in particular of the towing vehicle. In particular, this position enables a reliable detection of the environment and thus provides reliable information about the height of the vehicle trailer and optionally about each route ahead, in which an obstacle is passed. Therefore, the safety according to this embodiment is improved particularly effectively. Apart from that, in particular, by positioning the sensor on the top of the roof, it is possible to use only one sensor both for determining the height of the vehicle trailer and the height of the track section. This may also be advantageous, as described in detail below.

With regard to further technical features or advantages of the described method, reference is made to the description of the driver assistance system, the description of the vehicle, the figures and the description of the figures, and vice versa.

The present invention further relates to a driver assistance system for determining a critical height of a preceding track section, wherein the driver assistance system has at least one environment sensor for optionally detecting an obstacle at a track section in front of the vehicle, optionally detecting the height of a track section along the obstacle, and detecting the Height of the vehicle and thus in particular the maximum load on a trailer. The driver assistance system may further include a controller for processing the data of the at least one environmental sensor and optionally for comparing the height of the forward link with the height of the vehicle, wherein at least one of the at least one environmental sensor and the controller are suitable for performing a method as described above.

Therefore, the described driver assistance system provides an improved procedure for determining a critical altitude of a track ahead. In particular, the method described provides a procedure that is capable of determining a critical altitude of a track ahead and that can be performed automatically and in real time. Furthermore, in contrast to the methods described in the prior art, it is not necessary to provide a known or estimated height of the vehicle, for example the unloaded vehicle, or parts thereof as an input value.

In particular, the driver assistance system is adapted to dynamically recalculate the amount of vehicle trailer load each time the system is turned on. This is also possible regardless of varying trailer loads. The system will always provide accurate information about the amount of cargo.

This can improve traffic safety for all users and reduce the risk of collisions with low-hanging obstacles or other obstacles, without having to manually measure the amount of trailer load for each trip.

With regard to further technical features or advantages of the described driver assistance system, reference is made to the description of the method, the description of the vehicle, the figures and the description of the figures and vice versa.

The present invention further relates to a vehicle comprising a towing vehicle and a trailer, wherein the vehicle has a driver assistance system for determining a critical height of a preceding route section, characterized in that the driver assistance system is configured as described above.

The vehicle provides a substantial and reliable reduction of the risk of collision and thus provides an improved safety behavior, as described in detail above.

It may be particularly preferred if the at least one environmental sensor is arranged on the roof of the towing vehicle. In this case, particularly reliable information can be provided.

With regard to further technical features or advantages of the described vehicle, reference is made to the description of the driver assistance system, the description of the method, the figures and the description of the figures and vice versa.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described below. Individual features set forth in the embodiments may, alone or in combination, form an aspect of the present invention. Features of the various embodiments are transmittable from one embodiment to another embodiment.

• 1 zeigt schematische eine Ansicht eines Szenarios mit einem Fahrzeug, das zum Ausführen eines erfindungsgemäßen Verfahrens geeignet ist; und
• 2 zeigt schematische eine Ansicht eines weiteren Szenarios mit einem weiteren Fahrzeug, das zum Ausführen eines erfindungsgemäßen Verfahrens geeignet ist.

In the figures:

• 1 schematically shows a view of a scenario with a vehicle, which is suitable for carrying out a method according to the invention; and
• 2 schematically shows a view of another scenario with another vehicle, which is suitable for carrying out a method according to the invention.

1 shows a vehicle 10 that is a towing vehicle 12 and a trailer 14 includes, the trailer 14 with the towing vehicle 12 connected is. The vehicle 10 moves in the forward direction and is along a route ahead 16 drive. The route ahead 16 gets along an obstacle 18 run. According to 1 is the obstacle 18 from a tree 20 while the obstacle 18 in 2 through a tunnel 22 is formed.

Due to the obstacle 18 that is at least partially over the stretch of road 16 located, the section of road indicates 16 a limited amount, as indicated by the arrow 24 is shown. The vehicle 10 or the vehicle trailer 14 has one by the arrow 26 illustrated height. To enable a safe journey, the vehicle points 10 a driver assistance system that is adapted to a method for determining a critical height of the track section 16 perform as described below.

The method performed by the driver assistance system first comprises the step of providing at least one environmental sensor 28 on. According to 1 is an environment sensor 28 on the roof of the towing vehicle 10 arranged, with the environment sensor 28 is designed as a fisheye camera.

The environmental sensor 28 becomes for detecting the obstacle 18 at the section of track 16 in front of the vehicle 10 and further detecting the height of the link 16 along the obstacle 18 provided. This can be done, for example Supply the data of the environmental sensor 28 that's the obstacle 18 detected to be executed to a control unit.

The step for detecting the height of the route section 16 can be performed for example by means of 3D reconstruction. In this regard, the maximum height of the next leg of the route 16 by detecting forward sensor data sensed by the forward-facing environmental sensor 28 be recorded. A data processor or controller may be operable to operate the sensor 28 to use. Driver assistance systems are typically capable of processing sensor information to determine the size, distance, and speed of objects within the detection area in front of the viewed or own vehicle 10 capture.

Further, the environmental sensor 28 suitable for the height of the vehicle trailer 14 This step is performed by determining the height of the vehicle trailer 14 relative to the sensor 28 , Determining the absolute position of the sensor 28 and calculating the absolute height of the vehicle trailer 14 based on the result of the steps defined above. In this regard, determining the height of the vehicle trailer 14 relative to the sensor 28 by background subtraction in combination with the use of parallax effects.

With regard to background subtraction and in the event that the vehicle 10 together with his trailer 14 drives and in particular, when the vehicle 10 and the trailer 14 moving in a straight line become the trailer 14 and its charge relative to the environmental sensor 28 be static. Whether the vehicle 10 and the trailer 14 moving in a straight line can be determined, for example, according to the steering angle or the trailer angle detection, as is known in the art. Using the background subtraction, the area in the image in which the trailer is located can be determined 14 and the charge are located. The top pixel of the trailer 14 or its load, and thus the structure that does not move in a straight line, represents the highest point of the load and thus the maximum height of the trailer 14 which is to be recorded.

In addition, a distance of the charge and thus the specific highest pixel to the sensor 28 be captured to the maximum height of the trailer 14 to determine. This may be required due to the fact that, although the highest pixel is known and thus the angle to the horizontal axis is known, the height and thus the relative height to the sensor 28 from the distance of the pixel from the sensor 28 depends. The distance of the sensor 28 to charge and thus the horizontal distance between the sensor 28 and the maximum height of the charge can be determined, for example, using the well-known parallax effects. In this case, the known horizontal distance from the sensor 28 to the connection point 30 of the trailer 14 with the towing vehicle 12 where the trailer with the towing vehicle 12 rotatably connected, can be used. This may be, for example, a known value that is stored in a driver assistance system and, for example, may have the length of the drawbar, as indicated by the arrow 42 is shown.

Accordingly, when the vehicle 10 a curve drives, the trailer angle detection, which is generally part of towing vehicles 12 is the angle to the axis of the towing vehicle 12 capture, over which the trailer 14 has moved. Once the highest point on the trailer 14 and thus the highest charge was detected using the background subtraction described above, the extent to which the pixel is moving appears to be less than the detected trailer angle. This is a known parallax effect. Then the apparent change of movement between the highest charge of the trailer 14 and the connection point 30 used to determine the relative distance from the connection point 30 of the trailer 14 , such as from the point of the drawbar, the sensor 28 closest is to calculate the highest charge in a simple way. It is thus easily possible to scale this to an absolute distance. It is then possible to derive the height relative to the sensor from this distance and the projected beam of the highest pixel, as indicated by the arrow 34 is shown.

It then requires the absolute height of the sensor 28 to determine how by the arrow 36 is shown. This can be done for example by means of a camera calibration. With regard to camera calibration or sensor calibration 28 can the height of the sensor 28 among other things, by identifying at least two feature points in at least two sensor images of a vehicle 10 be determined, which has moved between the images. The method then determines a sensor translation direction between two sensor positions. The method then determines a ground plane in sensor coordinates based on the corresponding feature points from the images and the sensor translation direction.

The method then determines a height of the sensor 28 above the ground in vehicle coordinates.

In addition, the speed of the moving vehicle 10 can be used to calculate the distance of the reference points traced between frame frames, which determines the height of the sensor 28 allows. Therefore, the height of the sensor 28 from the ground level, such as from a road, can be determined when the speed of the vehicle 10 is known. If the speed of the vehicle 10 is taken into account is the actual physical distance between the tracked features on the road surface and the sensor 28 for example, using triangulation known.

If the height of the section of track 16 and the maximum amount of cargo of the trailer 14 by combining the relative height of the charge relative to the sensor 28 and the absolute height of the sensor 28 determined, these values can be compared to determine if a critical altitude of the preceding leg 16 is present.

Therefore, as illustrated above, it may be determined if a scenario occurs in which the height of the vehicle 10 according to a predetermined amount is smaller than the height of the route section lying ahead 16 , Ie, in general, if the height of the vehicle 10 is smaller than the height of the section ahead 16 ensure that the vehicle 10 the obstacle 18 can happen and thus a danger for a collision of the vehicle 10 with the obstacle 18 can be excluded. In this regard, it can be taken into account that the height of the vehicle 10 generally not smaller than the height of the next section of track 16 but it may be smaller according to a predetermined amount. In this regard, the given measure may reflect a kind of security that allows a particularly high level of security by allowing for a security area. The predetermined dimension and thus the security range can be defined according to the desired requirements.

Furthermore, it can be provided that the predetermined value for each obstacle 18 is redefined. For example, in the case that the height of the stretch 16 varies, indicating that the obstacle 18 For example, a tree or a street lamp, which moves for example by the influence of strong winds. In this case, the predetermined value can be selected such that the safety margin is increased.

On the other hand, in the case that the height of the stretch 16 and thus the lower limit of the obstacle 18 at the track is constant, this indicate that the obstacle 18 for example, a building, such as a tunnel 22 or a bridge, in which case the security area can be selected to be comparably small and the predetermined value can be selected accordingly.

According to this scenario, no collision with the obstacle is to be expected.

On the other hand, however, in the case that the height of the vehicle 10 to a lesser extent smaller than the height of the section of track ahead, according to the given measure 16 is, or if the height of the vehicle 10 the height of the next section of track 16 equal to or the height of the vehicle 10 is greater than the height of the section ahead 16 , be determined that a critical height of the forward section 16 is present and therefore a collision is likely or at least can not be excluded.

In the case that the height of the vehicle 10 is smaller to a lesser extent than the height of the section of road ahead according to the given measure 16 , the given measure can reflect a safety area that is appropriate for each obstacle 18 can be defined as described in detail above.

In accordance with the above, if a critical altitude of the forward section 16 is determined, issued a warning to a driver or emergency braking activated. Therefore, a substantial improvement in safety can be provided that substantially reduces the risk of collision.

1 shows an embodiment according to which the at least one environmental sensor 28 is a single sensor that provides information for both determining the height of the track ahead 16 as well as the height of the vehicle 10 provides. This can be realized for example by a fisheye camera having a wide field of view, for example of more than 180 °, as by the arrow 32 above the sensor 28 is shown. Therefore, the sensor can 28 both for detecting the height of the route ahead 16 as well as the vehicle 10 or the vehicle trailer 14 be used.

In contrast to 1 shows 2 an embodiment in which a first environmental sensor 28a is provided, the information for determining the height of the route section ahead 16 and a second environmental sensor 28b is used, the information to Determine the height of the vehicle 10 supplies. The fields of view of the sensors 28a . 28b are by arrows 38 . 40 shown. In this context, the environmental sensors 28a . 28b be designed as image sensors or cameras, infrared cameras, laser scanner / LIDAR sensors, LADAR sensors, RADAR short and wide range sensors, ultrasonic sensors and / or the like.

LIST OF REFERENCE NUMBERS

10

vehicle

12

towing vehicle

14

pendant

16

stretch

18

obstacle

20

tree

22

tunnel

24

arrow

26

arrow

28

sensor

28a

sensor

28b

sensor

30

junction

32

arrow

34

arrow

36

arrow

38

arrow

40

arrow

42

arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 9269263 B2 [0003, 0050]
• WO 2012/139636 A1 [0005, 0046]

Claims (13)

A method of determining a critical height of a forward link (16) for a vehicle (10) comprising a towing vehicle (12) and a trailer (14), the method comprising the steps of: a) providing at least one environmental sensor (28); b) optionally detecting an obstacle (18) at a distance ahead of the vehicle (10); c) optionally detecting the height of a track section (16) along the obstacle (18); d) detecting the height of the vehicle trailer (14); and e) optionally comparing the height of the vehicle trailer (14) with the height of the track section (16); characterized in that the height of the vehicle trailer (14) is determined by the steps of: d1) determining the height of the vehicle trailer (14) relative to the sensor (28); d2) determining the absolute position of the sensor (28); and d3) calculating the absolute height of the vehicle trailer (14) based on the result of steps d1) and d2) Method according to Claim 1 , characterized in that step d1) is performed by background subtraction in combination with the use of parallax effects. Method according to Claim 1 or 2 , characterized in that step d2) is carried out by means of sensor calibration. Method according to one of Claims 1 to 3 , characterized in that the height of the track section (16) is determined by three-dimensional reconstruction. Method according to one of Claims 1 to 4 characterized in that the method comprises the steps of: b) detecting an obstacle (18) at a distance ahead of the vehicle (10); c) detecting the height of a track section (16) along the obstacle (18); and e) comparing the height of the vehicle trailer (14) with the height of the track section (16). Method according to Claim 5 characterized in that, in the case that the height of the vehicle (10) is smaller than the height of the next leg (16) or the height of the vehicle (10) is equal to or higher than the height of the next leg (16) according to a given measure the height of the vehicle (10) is greater than the height of the forward path section (16), a warning message is issued to a driver of the vehicle (10). Method according to one of Claims 1 to 6 , characterized in that the at least one environmental sensor (28) on the roof of the towing vehicle (12) is arranged. Method according to one of Claims 1 to 7 characterized in that the at least one environmental sensor (28) is a single sensor providing information for both determining the height of the forward link section (16) and the height of the vehicle (10). Method according to Claim 8 , characterized in that the sensor (28) is selected from a fisheye camera and a LIDAR sensor. Method according to one of Claims 1 to 7 characterized in that at least one first environment sensor (28a) is provided which provides information for determining the height of the forward path section (16), and at least one second environment sensor (28b) is used, the information for determining the height of the vehicle (10 ). A driver assistance system for determining a critical altitude of a preceding track section (16), the driver assistance system comprising at least one environment sensor (28) for optionally detecting an obstacle (18) at a distance ahead of the vehicle (10), optionally detecting the altitude of a forward track section (16 ) along the obstacle (18) and for detecting the height of the vehicle (10), wherein the driver assistance system further comprises a control unit for processing the data of the at least one environmental sensor (28) and optionally comparing the height of the forward track section (16) with the Height of the vehicle (10), characterized in that at least one of the at least one environmental sensor (28) and the control unit for carrying out a method according to one of Claims 1 to 10 are suitable. A vehicle comprising a towing vehicle (12) and a trailer (14), the vehicle (10) having a driver assistance system for determining a critical height of a forward path section (16), characterized by the driver assistance system according to Claim 11 is configured. Vehicle after Claim 12 , characterized in that the at least one Environmental sensor (28) on the roof of the towing vehicle (12) is arranged.

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