Assistance system for a motor vehicle and method for assisting a driver of a motor vehicle

Abstract

Assistance system for a motor vehicle (100), comprising: - a detection device (130) for optically detecting a rear environment of the motor vehicle (100), - a warning device (140) for generating a warning signal, and - an evaluation device (120) which is designed to analyze a current driving behavior of a driver of the motor vehicle (100) on the basis of the detected surroundings of the motor vehicle (100), and to cause the warning device (140) to generate the warning signal if the evaluation device (120) detects a deviation of the driving behavior from a desired behavior, characterized in that the detection device (130) is designed to detect the surroundings to the rear of the motor vehicle (100), wherein the evaluation device (120) is designed to determine a traveled trajectory (200) of the motor vehicle (100) on the basis of the detected surroundings to the rear of the motor vehicle (100) as part of the analysis of the driving behavior, wherein the evaluation device (120) is designed to compare a current section of the trajectory (200) with a further back section of the trajectory (200),using statistical methods.

Description

[0001] The present invention relates to an assistance system for a motor vehicle and a method for assisting a driver of a motor vehicle, wherein the driver is warned if the driving behavior deviates from a desired behavior. State of the art

[0002] The published patent application US 2009 / 0 069 973 A1 discloses a warning method.

[0003] The patent DE 197 49 583 B4 discloses a method and a device for observing or monitoring an object space from a motor vehicle.

[0004] The published patent application DE 10 2006 010 662 A1 discloses a lane change warning system.

[0005] Scientific studies estimate that between ten and twenty percent of all serious traffic accidents are due to driver fatigue or inattention. To prevent accidents, assistance systems are increasingly being used that can detect a driver's condition or any deviation from a desired behavior. Such systems are currently found primarily in luxury vehicles.

[0006] Today's driver condition detection systems are usually based on camera systems in the vehicle that capture the driver's face and detect blinking. This allows the system to detect whether the driver is falling asleep, so-called microsleep, and warn the driver in a timely manner.

[0007] In addition, assistance systems are known that use a front camera to optically capture the surroundings in front of a vehicle and determine the vehicle's position in the lane based on lane markings. Such systems are designed to derive the driver's performance based on lane keeping accuracy and, based on this, generate a drowsiness warning. However, the disadvantage is that the use of such a system with a front-facing camera is relatively costly and, as a result, is currently limited to luxury vehicles. Disclosure of the invention

[0008] The object of the invention is to provide an improved assistance system for a motor vehicle and an improved method for assisting a driver of a motor vehicle.

[0009] This object is achieved by an assistance system according to claim 1 and by a method according to claim 5. Further advantageous embodiments of the invention are specified in the dependent claims.

[0010] According to the invention, an assistance system for a motor vehicle is proposed, which comprises a detection device for optically detecting the surroundings of the motor vehicle, a warning device for generating a warning signal, and an evaluation device. The evaluation device is designed to analyze the driver's current driving behavior based on the detected surroundings of the motor vehicle. The evaluation device is further designed to cause the warning device to generate a warning signal if the evaluation device detects a deviation of the driving behavior from a desired behavior. The assistance system is characterized in that the detection device is designed to detect the surroundings to the rear of the motor vehicle.

[0011] Instead of capturing the surroundings to the front of the vehicle, the assistance system uses the detection device to capture the surroundings to the rear. Such rear detection devices are now more widespread than the front cameras described above and are used, for example, as reversing cameras to facilitate reversing a vehicle. Furthermore, rear detection devices will become more widespread due to legal regulations – for example, in the USA, to prevent rollover when reversing ("backover avoidance"). This situation is exploited by the assistance system to use the detection devices already in use or to be required in the future to determine the driver's condition.

[0012] In a preferred embodiment, the evaluation device is configured to determine a traveled trajectory of the motor vehicle based on the detected rear environment of the motor vehicle as part of analyzing the driving behavior. This can be achieved, in particular, by the evaluation device detecting road and lane markings in the detected rear environment. Based on the traveled trajectory, the evaluation device can reliably determine any deviation of the driving behavior from a target behavior.

[0013] For this purpose, the evaluation device is designed to compare a current or recent section of the trajectory with a section of the trajectory further back. From the previous section of the trajectory, the evaluation device can derive properties that are linked to the driver's specific driving behavior. In this case, the previous section can relate in particular to the start of a journey, whereby it can be assumed that the driver was still awake and fit to drive at that time. The previous section of the trajectory can therefore serve, for example, as a "target trajectory", so that by comparing the current section of the trajectory with this reference trajectory, a deviation from a target behavior can be determined.

[0014] In an alternative or additional embodiment, the evaluation device is preferably designed to evaluate an estimated time until a (possible) crossing of a lateral lane boundary or side boundary line (“time-to-line crossing”) on the basis of the movement path in order to draw conclusions about the ability to drive.

[0015] In a further preferred embodiment, the assistance system further comprises a device for determining a current location of the motor vehicle on a road. The evaluation device is designed to additionally analyze the driving behavior based on the determined location of the motor vehicle. In this way, it is possible to take into account the exact (future) road course in addition to the detected surroundings to the rear of the motor vehicle when analyzing the driving behavior, whereby a deviation from a desired behavior can be detected with a high degree of accuracy and reliability. The device for determining the current location can, in particular, comprise a receiver for receiving a location signal and a device for providing a digital map.

[0016] In addition, the assistance system can include one or more additional devices or be linked to other devices, allowing the evaluation system to consider additional signals or information when analyzing driving behavior. Examples of such signals include turn signal signals.

[0017] In a further preferred embodiment, the evaluation device is designed to estimate a (future) course of a road to be traveled as part of analyzing the driving behavior. The evaluation device can apply a statistical extrapolation method for this purpose.

[0018] In a further preferred embodiment, the warning device is designed to generate the warning signal optically, acoustically and / or haptically.

[0019] The invention further proposes a method for assisting a driver of a motor vehicle, which comprises optically detecting the surroundings of the motor vehicle, analyzing the driver's current driving behavior based on the detected surroundings of the motor vehicle, and generating a warning signal if a deviation of the driving behavior from a desired behavior is detected. The method is characterized in that the surroundings to the rear of the motor vehicle are detected. Similar to the assistance system described above, the method exploits the fact that rear-mounted detection devices are already relatively widespread and will become so in the future.

[0020] The invention is explained in more detail below with reference to the figures. They show: Fig. 1 a schematic representation of a motor vehicle with an assistance system when driving on a road; and Fig. 2 a schematic block diagram of another assistance system.

[0021] Fig. Figure 1 shows a schematic representation of a motor vehicle 100 driving along a road. The road is illustrated by lane markings, ie, lateral lane markings 210 and a central reservation 211. The motor vehicle 100, which, as in Fig. 1, which may be a conventional passenger car, is equipped with an assistance system 110. With the help of the assistance system 110, a driver of the motor vehicle 100 can be warned in the event of fatigue or inattention, thereby achieving improved road safety.

[0022] The assistance system 110 has a device 120 for data processing, evaluation, and control, which is referred to below as the evaluation device 120. Another possible designation for the evaluation device 120 is "control unit," "processing unit," or "head unit." The evaluation device 120 is connected to a camera 130 arranged on the rear of the motor vehicle 100 and to a warning device 140. The camera 130 is used to optically capture the surroundings to the rear of the motor vehicle 100. Based on the captured surroundings to the rear, the evaluation device 120 analyzes the driving behavior, as described further below, and causes the warning device 140 to generate a warning signal if the evaluation device 120 detects a deviation from a target behavior.

[0023] Since the camera 130 can also be used to facilitate reversing, the camera 130 is referred to below as the rear view camera 130. The use of the rear view camera 130 may, for example, be required by law to prevent third parties from being run over when reversing. The images recorded by the rear view camera 130 are displayed on a display device or a screen within the motor vehicle 100. An angular sector or detection area 230 covered by the rear view camera 130 is shown in Fig. 1 indicated by lines.

[0024] The warning device 140, which is activated by the evaluation device 120 when a deviation from a desired behavior is detected, is designed to generate the warning signal optically, acoustically, and / or haptically. The warning device 140 comprises, for example, a display or indicator on which a graphic warning signal can be reproduced. The display can, in particular, be the display device described above, on which the images recorded by the rearview camera 130 are projected. Furthermore, the warning device 140 can comprise a loudspeaker or a loudspeaker system to generate an acoustic warning signal. The loudspeaker system can be part of an audio system of the motor vehicle 100. To generate a haptic warning, the warning device 140 comprises, for example, a haptic module.The haptic module, with the aid of which a warning in the form of vibrations can be generated, is integrated, for example, in the driver's seat or the steering device of the motor vehicle 100.

[0025] For an analysis of the driving behavior, the evaluation device 120 determines the position of the motor vehicle 100 on the road(s) traveled over time based on the environment detected from the rear, and determines a traveled trajectory 200 of the motor vehicle 100, as shown in Fig. 1 is indicated by a dashed line. The evaluation device 120 is designed, in particular, to detect road and lane markings 210, 211 of the respective road being traveled on in order to track the position of the motor vehicle 100. Further indicators by which the evaluation device 120 can determine the trajectory 200 of the motor vehicle 100 include, for example, contrast differences in the area of ​​curbs and road edges.

[0026] Based on the determined trajectory 200 of the motor vehicle 100, the evaluation device 120 performs an analysis of the driving behavior. For this purpose, the evaluation device 120 compares a current or recent section of the trajectory 200 with a more recent section, using statistical methods. In doing so, the evaluation device 120 records specific features and properties of the trajectory 200 that are linked to the driver's driving behavior in order to compare them. These features include, for example, (typical) steering and swerving movements that occur during driving.

[0027] As a past section of the trajectory 200, which can function as a "target trajectory," the evaluation device 120 can, in particular, consider a section at the beginning of the journey with the motor vehicle 100, so that normal, attentive driving behavior can be assumed. In other words, the evaluation device 120 calculates parameters of a "target behavior" from the past section of the trajectory 200. By comparing the specific properties of the past and the current section of the trajectory 200, the evaluation device 120 can consequently determine whether the current driving behavior deviates from a target behavior or whether the deviation is of such a magnitude that it suggests fatigue or inattention on the part of the driver, in order to warn the driver (by activating the warning device 140).

[0028] In addition to the above-described evaluation of the trajectory 200 or comparison of sections of the trajectory 200, the evaluation device 120 can additionally or alternatively use further "indications" to detect a deviation of the driving behavior from a target behavior. One possible method is for the evaluation device 120 to estimate a (near) future course by extrapolation based on the road course detected from the rear, and to take this into account when analyzing the current driving behavior or when using a target behavior as a basis.

[0029] The assumed future road course can be compared, in particular, with the current position and direction of movement of the motor vehicle 100 on a road in order to determine any deviation from a target behavior. The position and direction of movement of the motor vehicle 100 are determined based on the rear environment captured by the rear-view camera 130 or based on a current section of a movement path 200. If, for example, a straight section of road (captured from the rear) is present and the (current) movement of the motor vehicle 100 is diagonal to the road, so that an (imminent) departure from the road and thus a deviation from a target behavior can be assumed, the evaluation device 120 can also cause the warning device 140 to generate a corresponding warning signal in such a case.

[0030] In the procedures described above, the analysis of the current driving behavior is based on the rear environment captured by the rearview camera 130 and any extrapolation performed. However, it is also conceivable to additionally consider the geographical location of the motor vehicle 100 on a road obtained by positioning, which allows the attention determination to be carried out with high accuracy and reliability.

[0031] For illustration purposes, Fig. 2 shows a schematic block diagram of a further assistance system 111, which is also used in the motor vehicle 100 of Fig. 1 can be used. Like the assistance system 110, the assistance system 111 has a rearview camera 130, an evaluation device 120, and a warning device 140. For details on these components, reference is therefore made to the above explanations.

[0032] As further components, the assistance system 111 includes a receiver 150 for receiving a location signal—for example, a GPS signal—by means of which the current geographical position of the motor vehicle 100 can be determined. A device 160 for providing a digital map is also provided. The device 160 is, for example, a storage device in which the digital map is stored. It is also possible to provide the device 160 as a reading device into which a storage medium, such as a memory card or a memory stick containing map information, can be inserted. The assistance system 111 can represent a navigation system or part of such a system.

[0033] In addition, the assistance system 111 can be used as in Fig. 2, a device 170 for determining a vehicle speed (speedometer) or a distance traveled (odometer), as well as a yaw rate sensor 180 for determining a yaw rate of the motor vehicle 100. The yaw rate sensor 180 can simultaneously be a component for a vehicle dynamics control system, such as, in particular, ESP (Electronic Stability Program).

[0034] Based on a positioning signal received by receiver 150 and the map provided by device 160, evaluation device 120 can determine the current location of motor vehicle 100 on a road and thus the exact future route of motor vehicle 100. This information is used by evaluation device 120 in addition to analyzing current driving behavior or as a basis for determining a desired behavior. Even without receiving a GPS signal, for example, when driving through a tunnel or in a narrow city center, evaluation device 120 can determine the location of motor vehicle 100 using the outputs of speedometer / odometer 170 and yaw rate sensor 180 together with the digital map provided by device 160.

[0035] Based on the road course estimated by extrapolation, the (upcoming) route of motor vehicle 100, known from the location, can be compared with the current position and direction of movement of motor vehicle 100 on a road in order to determine a deviation from a desired behavior or an (imminent) departure from the road. The position and direction of movement of motor vehicle 100 are determined based on the surroundings behind the vehicle captured by rearview camera 130 or based on a current section of a trajectory 200 (if such a trajectory 200 is determined).

[0036] In addition, the assistance system 111 can be used as in Fig.2, the evaluation device 120 may comprise one or more additional devices 190 or be coupled to such a device 190 in order to supply the evaluation device 120 with additional vehicle signals or information that can be taken into account in the analysis of the current driving behavior. For example, turn signal signals are possible, in order to be able to detect, for example, an intended lane departure based on them.

[0037] The embodiments explained with reference to the figures represent preferred or exemplary embodiments of the invention for detecting a driver's condition by evaluating image sequences from a rearview camera. Instead of the described embodiments, further embodiments are conceivable, which may include further modifications or combinations.

Claims

[1] Assistance system for a motor vehicle (100), comprising: - a detection device (130) for optically detecting a rear environment of the motor vehicle (100), - a warning device (140) for generating a warning signal, and - an evaluation device (120) which is designed to analyze a current driving behavior of a driver of the motor vehicle (100) on the basis of the detected surroundings of the motor vehicle (100), and to cause the warning device (140) to generate the warning signal if the evaluation device (120) detects a deviation of the driving behavior from a desired behavior, characterized in that the detection device (130) is designed to detect the surroundings to the rear of the motor vehicle (100), wherein the evaluation device (120) is designed to determine a traveled trajectory (200) of the motor vehicle (100) on the basis of the detected surroundings to the rear of the motor vehicle (100) as part of the analysis of the driving behavior, wherein the evaluation device (120) is designed to compare a current section of the trajectory (200) with a further back section of the trajectory (200),using statistical methods. [2] Assistance system according to claim 1, further comprising a device (150, 160, 170, 180) for determining a current location of the motor vehicle (100) on a road, wherein the evaluation device (120) is designed to additionally analyze the driving behavior on the basis of the determined location of the motor vehicle (100). [3] Assistance system according to claim 1 or 2, wherein the evaluation device (120) is designed to estimate a course of a road to be traveled as part of the analysis of the driving behavior. [4] Assistance system according to one of the preceding claims, wherein the warning device (140) is designed to generate the warning signal optically, acoustically and / or haptically. [5] Method for assisting a driver of a motor vehicle (100), comprising the method steps: - optical detection of a rear environment of the motor vehicle (100), - analyzing a current driving behavior of the driver on the basis of the detected surroundings of the motor vehicle (100), wherein the analyzing of the driving behavior comprises determining a traveled trajectory (200) of the motor vehicle (100) on the basis of the detected rear surroundings of the motor vehicle (100), wherein the analyzing of the driving behavior further comprises comparing a current section of the trajectory (200) with a further back section, wherein statistical methods are used, and - generating a warning signal if a deviation of the driving behavior from a target behavior is detected, characterized in that the rear environment of the motor vehicle (100) is detected. [6] Method according to claim 5, further comprising determining a current location of the motor vehicle (100) on a road, wherein the analysis of the driving behavior is additionally carried out on the basis of the determined location of the motor vehicle (100). [7] Method according to claim 5 or 6, wherein analyzing the driving behavior comprises estimating a course of a road to be traveled. [8] Method according to one of claims 5 to 7, wherein the warning signal is generated optically, acoustically and / or haptically.

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