Method for detecting a trailer, and method for controlling a vehicle function

Abstract

The invention relates to a method for detecting (10) a trailer (54) of a vehicle (52), having the steps of providing vehicle surroundings sensor data (12) of a surroundings sensor (14) which is paired with the vehicle (52) and which detects at least one vehicle (52) surrounding region (46) that at least partly includes the trailer (54), and generating a trailer model (30) in order to identify (22) trailer sensor data (18), which is to be assigned to a trailer, at least including a trailer wheel (48) of an axle (50) of the trailer (54), in the vehicle surroundings sensor data (12), wherein the trailer model (30) is generated on the basis of a classification (23) in which the vehicle surroundings sensor data (12) is categorized into at least one first class (18.1) which characterizes at least the trailer axle (50). The invention additionally relates to a method for controlling (38) a vehicle function (40).

Description

[0001] Description

[0002] Title:

[0003] Method for trailer detection and method for controlling a vehicle function

[0004] The invention relates to a method for trailer detection according to claim 1. Furthermore, the invention relates to a method for controlling a vehicle function.

[0005] State of the art

[0006] DE 102019220 526 A1 describes a method for determining at least one articulation angle of a vehicle combination consisting of a vehicle and a trailer, in which a position and / or number of wheels of the trailer is determined on the basis of calculated position information by determining micro-Doppler information on the basis of determined radar data and an axle position of axles of the trailer of the vehicle combination is calculated.

[0007] Disclosure of the invention

[0008] According to the present invention, a method for trailer detection is proposed with the features of claim 1. This allows the vehicle with trailer to be operated more reliably and accurately, especially when cornering.

[0009] The vehicle may be a motor vehicle, in particular a truck or a bus. The vehicle may be a two-wheeled vehicle, in particular a motorcycle.

[0010] A trailer is understood to be a vehicle part that can be decoupled from the vehicle or permanently connected to it and is movable relative to the vehicle and has at least one trailer axle with at least one trailer wheel rolling on a roadway, in particular trailing the vehicle. The trailer and the vehicle can form a vehicle combination. The trailer can be the rear part of a

[0011] It can be an articulated bus, a truck trailer, a semi-trailer, or the like. The trailer can be a trailer that can be detachably connected to the vehicle via a coupling head on a drawbar.

[0012] The environment sensor can be a radar sensor, a camera, a lidar sensor, and / or an ultrasonic sensor. The environment sensor can use the vehicle environment sensor data to provide position information and / or speed information of objects in the vehicle's surroundings.

[0013] The vehicle environment sensor data can be processed or unprocessed measurement data from the environment sensor. The vehicle environment sensor data can include position and / or speed information of objects detected by radar reflections in the surrounding area detected by the radar sensor. The vehicle environment sensor data can be provided by multiple environment sensors of the vehicle.

[0014] The environment sensor can be assigned to a driver assistance system. The vehicle environment sensor data can also be provided to a driver assistance system. The driver assistance system can process the vehicle environment sensor data. The driver assistance system can be a blind spot monitoring system or a turning assistance system. The turning assistance system can monitor the area to the right and / or left of the vehicle and detect at least one object moving within it. If a possible collision between the vehicle and the object is calculated, a warning signal can be issued to the driver of the vehicle and / or an automated braking function can be triggered. The driver assistance system can be assigned to the vehicle independently of the trailer. The driver assistance system can be designed for operation with or without a trailer.

[0015] The environment sensor can be arranged on the vehicle.

[0016] The trailer model is a simulation model, in particular a computer model. The trailer model can provide an estimated trailer influence on the vehicle environment sensor data. The trailer influence can include a trailer position, at least one trailer dimension, and / or a trailer movement.

[0017] The classification may include a grouping or assignment. The classification may include a further class identifying the trailer body.

[0018] In a preferred embodiment of the invention, the trailer model is based on an initial trailer estimation model, which is used to estimate the trailer sensor data. The trailer estimation model can be based on estimated trailer parameters, possibly including existing vehicle parameters such as a yaw rate or vehicle speed. The trailer parameters can be verified using the created trailer model.

[0019] The classification can be performed on the estimated trailer sensor data.

[0020] In a preferred embodiment of the invention, it is advantageous if the trailer model is created iteratively by using the initial trailer estimation model to classify initial vehicle environment sensor data into at least the first class and processing multiple vehicle environment sensor data available in journals in individual calculation steps. The trailer estimation model can be updated after the first calculation step or after several calculation steps and saved as a trailer model. The saved trailer model can be updated again after a further calculation step or after several further calculation steps and saved as an updated trailer model.

[0021] In a specific embodiment of the invention, it is advantageous if the multiple vehicle environment sensor data are processed in individual calculation steps by identifying the trailer sensor data in the vehicle environment sensor data of a respective time step with the trailer model available at the respective calculation step and classifying them into the first class with the classification. The trailer model is adapted for reapplication to vehicle environment sensor data of a further time step in a subsequent calculation step depending on the classification. In one calculation step, vehicle environment sensor data aggregated over several time steps can be processed and identified as trailer sensor data, or only vehicle environment sensor data from a single time step can be processed.

[0022] In a preferred embodiment of the invention, it is advantageous if a trailer property of the trailer is calculated using the trailer model created based on the classification. This allows the trailer to be detected more accurately and its behavior in relation to the vehicle to be estimated.

[0023] In a preferred embodiment of the invention, it is advantageous if a trailer property is calculated by the trailer model when a minimum number of calculation steps and / or a minimum number of trailer sensor data are reached.

[0024] The trailer property can be a number of trailer axles of the trailer. The trailer property can be a trailer position relative to the vehicle, for example a lateral position and / or rotational position, in particular a bending angle. The rotational position can be variable during a rotational movement about a rotational axis formed by the trailer coupling of the vehicle. The lateral position can be variable during a braking operation by the trailer's overrun brake. The trailer property can be a trailer dimension, for example a trailer length and / or a trailer width. The trailer property can be a trailer axle position relative to the trailer or the vehicle. The trailer property can be a wheelbase of at least one trailer axle. The trailer property can be an average wheelbase of the multi-axle trailer.

[0025] In a preferred embodiment of the invention, the first class includes one or more trailer wheels of a trailer axle. The trailer sensor data can include all trailer wheels of all trailer axles of the trailer. Each trailer axle can be assigned a separate class.

[0026] In a preferred embodiment of the invention, the trailer has at least one additional trailer axle, and the classification includes an additional class identifying at least the additional trailer axle. For example, the first class can identify a first trailer axle, and a further class can identify a further trailer axle.

[0027] In a specific embodiment of the invention, it is advantageous if the trailer model includes a trailer movement dependent on at least one movement characteristic of the vehicle. The trailer model can characterize the trailer movement dependent on the movement characteristic of the vehicle. The movement characteristic can be a yaw rate and / or a speed of the vehicle.

[0028] The classified trailer sensor data belonging to the first class can be processed in an evaluation. Depending on the evaluation, the trailer model can be created and / or the trailer property can be calculated. For example, if the number of trailer axles is to be determined as a trailer property, various options for evaluating the trailer sensor data and thus the reflection points are possible when using a radar sensor as an environment sensor. The evaluation can, for example, be based on a frequency distribution of the reflection points assigned to the trailer wheels, which are specified by the trailer sensor data, in a polar coordinate system with the coupling point as the coordinate origin.

[0029] Alternatively or additionally, the speed information from the reflection points can be used and plotted in a vr-r diagram, in which the radial relative speed vr is specified as a function of the distance r from the coupling point or the environment sensor. The number of trailer axles can be calculated using a cluster search.

[0030] Alternatively or additionally, the reflection points can be specified in a histogram depending on the distance to the radar sensor or the distance to the coupling point. Various methods can be used to determine the number of trailer axles in this histogram. For example, a peakfinder algorithm could be used. However, if the trailer axles occur with different frequencies in the radar reflections, preprocessing the trailer sensor data may be useful, for example, by scaling the frequencies with distance.

[0031] According to the present invention, a method for controlling a vehicle function is further proposed, having the features of claim 9. The vehicle function can be assigned to a driver assistance system. The driver assistance system can be controlled depending on the trailer model.

[0032] The vehicle function can be a user display, for example, on a vehicle display. The user display can show a more detailed image of the trailer. The user display can be controlled depending on the trailer model.

[0033] In a preferred embodiment of the invention, the vehicle environment sensor data assigned to the trailer are identified as trailer sensor data in the vehicle environment sensor data by applying the trailer model. The trailer sensor data can be classified by applying the trailer model.

[0034] In a specific embodiment of the invention, it is advantageous if the control of the vehicle function is carried out depending on vehicle environment sensor data that has been adjusted for the trailer sensor data. This allows the control of the vehicle function to be carried out without being influenced by the presence of the trailer in the vehicle environment sensor data.

[0035] Furthermore, the invention relates to a vehicle control device for controlling a vehicle function according to one of the methods described above.

[0036] Further advantages and advantageous embodiments of the invention will become apparent from the description of the figures and the illustrations.

[0037] The invention is described in detail below with reference to the figures. They show in detail:

[0038] Figure 1: A method for trailer detection in a special embodiment of the invention.

[0039] Figure 2: A method for controlling a vehicle function of the vehicle in a specific embodiment of the invention.

[0040] Figure 3: A schematic representation of a vehicle and radar reflection points from example trailer sensor data.

[0041] Figure 4: A representation of reflection points from measured trailer sensor data.

[0042] Figure 5: A speed distribution of measured trailer sensor data.

[0043] Figure 6: A frequency distribution of measured trailer sensor data.

[0044] Figure 1 shows a method for trailer detection in a specific embodiment of the invention. The method for trailer detection 10 of a trailer of a vehicle initially comprises providing vehicle surroundings sensor data 12 from an environment sensor 14 assigned to the vehicle and detecting at least one surrounding area of ​​the vehicle that at least partially encloses the trailer. The environment sensor 14 is, for example, a radar sensor 16 that provides position and speed information about the detected vehicle surroundings in the surrounding area. The vehicle surroundings sensor data 12 preferably comprise position and speed information of objects detected by radar reflections in the surrounding area detected by the radar sensor 16.

[0045] Subsequently, the vehicle environment sensor data 12 assigned to the trailer, i.e., the vehicle environment sensor data 12 resulting from radar reflections of the trailer, are identified as trailer sensor data 18 in the vehicle environment sensor data 12 by applying an initial trailer estimation model 20. The trailer estimation model 20 can preferably incorporate estimated or known trailer parameters of the trailer, which, for example, are in turn obtained from information about the vehicle, such as the vehicle speed and / or yaw rate.

[0046] The identification 22 of the trailer sensor data 18 includes a classification 23, in particular of the trailer sensor data 18 assigned to a trailer axle into at least one first class 18.1 and / or the trailer sensor data assigned to the trailer body into a second class 18.2. The trailer sensor data 18 assigned to the ground reflections can also form a separate additional class.

[0047] The trailer sensor data identified in this way and preferably classified into the first and second classes 18.1, 18.2 are then processed in an evaluation 28 and, depending on the evaluation 28, the trailer model 30 is created based on the trailer estimation model 20.

[0048] Preferably, the trailer model 30 is created iteratively with a plurality of vehicle environment sensor data available in journals in individual calculation steps, in that initial vehicle environment sensor data 12.1 are classified into at least the first and second classes 18.1, 18.2 using the initial trailer estimation model 20, the trailer model 30.1 available for this calculation step is created based thereon, and the vehicle environment sensor data 12.2 assigned to at least one further journal are processed in a subsequent calculation step with the trailer model 30.1 by identifying the associated trailer sensor data 18 and reclassifying them, and the trailer model 30.1 is adapted for reapplication to vehicle environment sensor data 12 of a further time step in a subsequent calculation step depending on the classification, whereby the trailer model 30 is updated and created step by step during repeated runs.

[0049] When a minimum number 34 of calculation steps and / or a minimum amount of trailer sensor data 18 is reached, a trailer property 36 of the trailer, for example, a number of trailer axles, is calculated. This calculated trailer property 36 can, in turn, be used to update the trailer model 30. This allows the trailer model 30 to be gradually improved.

[0050] The trailer property 36, in turn, can be used to control 37 a vehicle function, such as a driver assistance system. For example, the performance of the driver assistance system can be improved when cornering.

[0051] Figure 2 shows a method for controlling a vehicle function of the vehicle in a specific embodiment of the invention. In the method for controlling 38 a vehicle function 40 of a vehicle with a trailer, vehicle surroundings sensor data 12 are recorded from an environment sensor 14 assigned to the vehicle and detecting at least one surrounding area of ​​the vehicle that at least partially encloses the trailer. The environment sensor 14 can be a radar sensor 16. The vehicle surroundings sensor data 12 can indicate radar reflections from objects in the vehicle surroundings.

[0052] By providing the trailer model 30 of the vehicle's trailer, created, for example, using the trailer detection method shown in Figure 1, the vehicle function 40 is controlled depending on the trailer model 30. For this purpose, in particular, the vehicle environment sensor data 12 assigned to the trailer are identified and classified as trailer sensor data 18 in the vehicle environment sensor data 12 by applying the trailer model 30, and vehicle environment sensor data 42 adjusted for the trailer sensor data 18 is output.

[0053] The control 37 of the vehicle function 40, for example, the control 37 of a driver assistance system, is in turn dependent on the cleaned vehicle environment sensor data 42. This allows the driver assistance system to function even when operating with a trailer. The trailer sensor data 18 indicates the radar reflections associated with the trailer and can be filtered out from the vehicle environment sensor data 12, i.e., the total radar reflections of the vehicle environment detected by the radar sensor 16, and the driver assistance system can be operated, in particular, as if no trailer were present.

[0054] In particular, the trailer model 30 is used together with position information and speed information (especially the micro-Doppler information) to detect the axle position of the trailer axle(s). Using the position information of the trailer axle(s), trailer parameters such as the wheelbase and the coupling position are continuously estimated in order to update the trailer model 30. The radar detections that can be assigned to the trailer model 30 with a certain probability are filtered so that no objects are assumed from these radar detections during the subsequent control 37 of the vehicle function 40.

[0055] The interaction of trailer model 30 and vehicle environment sensor data 12 enables reliable assignment and filtering of trailer-based radar detections, for example, in every driving situation of the vehicle with a trailer (particularly when driving straight ahead or cornering). This enables the control 37 of the vehicle function 40, preferably the driver assistance function, when towing a trailer, and erroneously excludes suspected surrounding objects due to trailer-based radar detections.

[0056] Figure 3 shows a schematic representation of radar reflection points from exemplary trailer sensor data. The trailer sensor data 18 can include the trailer wheels 48 of the three trailer axles 50 of the trailer 54 connected to the vehicle 52, as well as the trailer body 56, detected in the surrounding area 46 by the surrounding sensor 14 arranged on the vehicle 52 (here, the radar sensor 16). The trailer sensor data 18 can be classified as radar reflection points 58 of the trailer wheels 48 and as reflection points 60 of the trailer body 56.

[0057] The trailer model may include a trailer movement 62 of the trailer 54, for example a rotational movement about the coupling point 64 formed by the trailer hitch, depending on at least one movement characteristic of the vehicle 52.

[0058] If the trailer 54 moves around the coupling point 64, the articulation angle of the trailer 54 changes, thus the radar reflections of the trailer wheels 48 are distributed in circular paths 66 around the coupling point 64 of the trailer 54. The position of the radar reflection points 58, 60 assigned to the trailer wheels 48 is stored during the evaluation of the trailer sensor data obtained over several time steps, converted into a polar coordinate system with an origin at the coupling point 64 of the trailer 54, and displayed, for example, as a histogram (frequency plotted against radius).

[0059] Figure 4 shows a representation of reflection points from measured trailer sensor data. The measured trailer sensor data 18 result from a short measurement over a measuring time of a few minutes of a vehicle combination consisting of a tractor unit as shown in Figure 3 and a three-axle semi-trailer. The point groups of the three trailer axles can be seen, as well as that the frequency of the measured radar reflections, shown here as radar reflection points 58 of the trailer wheels, decreases for more distant trailer axles. For better clarity, the circular paths 66 of the trailer wheels are indicated by solid lines. The trailer sensor data available in the form of point groups in this coordinate system can be classified into a first class 18.1 corresponding to the first trailer axle, a second class 18.2 corresponding to the second trailer axle, and a third class 18.3 corresponding to the third trailer axle.

[0060] Figure 5 shows a speed distribution of measured trailer sensor data. The evaluation of the trailer sensor data 18 can be performed by a group search in a vr-r diagram, in which the radial relative speed vr is specified as a function of the distance r to the coupling point. Each radar reflection point 58 is detected by the radar sensor with a radial relative speed vr. The stored radar reflection points 58 are plotted as relative speeds of each radar reflection point 58 as a function of the distance r to the coupling point (or pivot point). The associated point groups 68 are indicated by dashed areas. Using the number of these point groups 68, corresponding to the classes identified by a classification, the desired number of trailer axles at the distances r1, r2, and r3 can be determined.

[0061] Figure 6 shows a frequency distribution of measured trailer sensor data. The number of trailer axles can be estimated directly from the histogram as a frequency distribution depending on the distance r from the radar sensor. The example histogram represents the wheelbase estimates from individual radar reflection points for a vehicle combination consisting of a semi-trailer and a three-axle semi-trailer as a trailer. The trailer sensor data entered in the histogram as reflection points originate from measured vehicle environment sensor data. The actual axle positions of the trailer axles are indicated as vertical dashed lines. The different frequency distributions of the measured reflections of the individual trailer axles are clearly visible.

[0062] Various methods can be used to determine the number of trailer axles in this histogram. For example, a peakfinder algorithm could be used. However, since trailer axles appear with varying frequencies in the radar reflections, preprocessing the trailer sensor data is useful, for example, by scaling the frequencies with the distance r from the radar sensor.

[0063] The results of the various evaluation methods can be combined. This could include simple weighting or more complex methods such as a type of filter or machine learning.

[0064] Since the stored trailer model is based on a single-track model, estimating the axle positions provides the opportunity to more accurately estimate the wheelbase for the trailer model. For example, if the trailer axles are not equidistant or if the wheelbase estimate is distorted by the frequency of visibility of the individual trailer axles, a more precise model calculation is possible.

Claims

Patent claims 1. A method for trailer detection (10) of a trailer (54) of a vehicle (52), comprising Providing vehicle environment sensor data (12) from at least one environment sensor (14) that is assigned to the vehicle (52) and detects at least one environment region (46) of the vehicle (52) that at least partially encloses the trailer (54), creating a trailer model (30) for identifying (22) trailer sensor data (18) that are to be assigned to a trailer, at least including a trailer wheel (48) that are to be assigned to a trailer axle (50) of the trailer (54), in the vehicle environment sensor data (12), characterized in that the trailer model (30) is created depending on a classification (23) in which the vehicle environment sensor data (12) are assigned to at least one first class (18.1) that characterizes at least the trailer axle (50).

2. Method for trailer detection (10) according to claim 1, characterized in that the trailer model (30) is based on an initial trailer estimation model (20) with which an estimative identification of the trailer sensor data (18) takes place.

3. Method for trailer detection (10) according to claim 2, characterized in that the trailer model (30) is created iteratively by classifying initial vehicle environment sensor data (12.1) into at least the first class (18.1) using the initial trailer estimation model (20) and processing a plurality of vehicle environment sensor data (12) available in magazines in individual calculation steps.

4. Method for trailer detection (10) according to claim 3, characterized in that the plurality of vehicle environment sensor data (12) are processed in individual calculation steps by identifying the trailer sensor data (18) in the vehicle environment sensor data (12.2) assigned to a respective journal with the trailer model (30.1) present at the respective calculation step and classifying them into the first class (18.1) with the classification, wherein the trailer model (30) is adapted for reapplication to vehicle environment sensor data (12) of a further time step in a subsequent calculation step depending on the classification.

5. Method for trailer detection (10) according to one of the preceding claims, characterized in that a trailer property (36) of the trailer (54) is calculated using the trailer model (30) created as a function of the classification (23).

6. Method for trailer detection (10) according to claim 3 or 4 and claim 5, characterized in that when a minimum number (34) of calculation steps and / or a minimum number of trailer sensor data (18) is reached, a trailer property (36) is calculated by the trailer model (30).

7. A method for trailer detection (10) according to claim 5 or 6, characterized in that the trailer property is a number of trailer axles (50) of the trailer (54).

8. Method for trailer detection (10) according to one of the preceding claims, characterized in that the trailer (54) has at least one further trailer axle (50) and the classification (23) includes a further class (18.2) characterizing at least the further trailer axle (50).

9. Method for controlling (38) a vehicle function (40) of a vehicle (52) with a trailer (54) by Vehicle environment sensor data (12) of an environment sensor (14) assigned to the vehicle (52) and detecting at least one environment region (46) of the vehicle (52) that at least partially encloses the trailer (54) are recorded, a trailer model (30) of a trailer (54) of the vehicle (52) created according to a method for trailer detection (10) according to one of the preceding claims is provided, and the vehicle function (40) is controlled depending on the trailer model (30).

10. Method for controlling (38) a vehicle function (40) according to claim 9, characterized in that the vehicle environment sensor data (12) assigned to the trailer (54) are stored as trailer sensor data (18) in the Vehicle environment sensor data (12) are identified by applying the trailer model (30) and the control (37) of the vehicle function (40) is carried out depending on vehicle environment sensor data (42) adjusted for the trailer sensor data (18).

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