Procedures for the safe operation of a motor vehicle

Abstract

Method for the safe operation of a motor vehicle (1) comprising at least one sensor unit (2) for recording environmental conditions and outputting environmental data, an evaluation unit (4) for assessing the environmental data, and an evaluation unit (5) for detecting free spaces and objects (O), their position and movement, as well as a driving safety coordinator (6) that determines the risk of collision of the motor vehicle (1) with an object (O) based on a hazard assessment, wherein the driving safety coordinator (6) issues an evasive maneuver recommendation to the driver or provides evasive maneuver support to the driver based on the criticality of the driving situation and the signal quality of the environmental data, or performs an autonomous evasive maneuver, wherein the driving safety coordinator (6) takes a more dominant measure the higher the criticality of the driving situation and the better the signal quality of the environmental data.where the signal quality of the environmental data is improved by means of data fusion of further data, and , a further sensor unit (20) detects the environmental condition and outputs environmental condition data to an evaluation unit (24) for data fusion of the environmental data with the environmental condition data to determine a friction coefficient indication, and a further sensor unit (30) detects the vehicle condition and outputs vehicle condition data to an evaluation unit (34) for data fusion of the vehicle condition data with the friction coefficient indication and the driver input data to determine the driving condition.

Description

[0001] The present invention relates to a method for operating a motor vehicle with at least one sensor unit for detecting the environmental conditions and for outputting environmental data, an evaluation unit for assessing the environmental data and an evaluation unit for detecting free spaces and objects, their position and movement, as well as with a driving safety coordinator which determines the risk of collision of the motor vehicle with an object based on a risk assessment.

[0002] EP 1 735 187 A1 discloses a method for increasing road safety. In this known system, a supporting driving maneuver is specified during or after a driver-initiated steering angle for an evasive maneuver, whereby the driver can override the specified maneuver at any time. The known method uses environmental signals to determine whether a critical driving dynamics situation or an impending collision exists. The method is primarily used in emergency situations for evasive maneuvers. An evaluation of the environmental signals does not take place.

[0003] DE 10 2007 039 038 A1 discloses a method for controlling safety devices in a motor vehicle in a driving situation in which a collision may occur between the motor vehicle and an object in the vicinity of the motor vehicle.

[0004] Furthermore, DE 10 2010 028 837 A1 describes a method for adapting a driver assistance system to the current driving situation, in which at least one parameter of the driver assistance system is adjusted depending on the information from an environmental sensor system.

[0005] In addition, DE 10 2005 003 177 A1 describes a device for preventing accidents of a vehicle when the vehicle is moving away from the vehicle, comprising at least one sensor system for detecting a driving dynamics parameter, a means for detecting a vehicle's own lane and a computing unit, wherein a maximum steering angle can be determined by the computing unit from the driving dynamics parameter and the detected lane.

[0006] It is an object of the present invention to improve a method of the type mentioned at the outset in such a way that an evaluation of the signal quality of the environmental data is carried out.

[0007] This object is achieved by a method having the features of independent patent claim 1. A method for the safe operation of a motor vehicle is proposed, in which the driving safety coordinator, based on the criticality of the driving situation and the signal quality of the environmental data, issues an evasive action recommendation to the driver or evasive action support for the driver or carries out an autonomous evasive action intervention, wherein the driving safety coordinator takes a more dominant action the higher the criticality of the driving situation and the better the signal quality of the environmental data.

[0008] The key idea of ​​the invention is that the driving safety coordinator assumes control over the motor vehicle, the higher the criticality of the driving situation and the better the signal quality of the environmental data, whereby the driving safety coordinator - provides evasive assistance to the driver if the signal quality of the surrounding data is low, - issues an evasive action recommendation to the driver and supports the evasive action if the signal quality of the surrounding data is medium and - carries out autonomous evasive intervention if the signal quality of the surrounding data is sufficiently good.

[0009] According to the invention, the signal quality of the environmental data is improved by means of a data fusion of further data.

[0010] It is intended that a further sensor unit detects the environmental condition and outputs environmental condition data to an evaluation unit for merging the surrounding data with the environmental condition data to determine a friction coefficient indication. Another sensor unit detects the vehicle condition and outputs vehicle condition data to an evaluation unit for merging the vehicle condition data with the friction coefficient indication and the driver input data to determine the driving condition. Furthermore, the driver inputs are detected by a further sensor unit, and driver input data is output to an evaluation unit for merging the driver input data with the vehicle condition data to determine the driver's target course.

[0011] An advantageous development of the method according to the invention provides that the driving safety coordinator issues a visual, acoustic and / or haptic warning to the driver before carrying out an autonomous evasive intervention.

[0012] Another crucial idea is that, in order to ensure operational safety, the driving safety coordinator predictively and situationally determines at least one permissible driving corridor and / or an optimal movement trajectory and limits the driver's input to the driving corridor by means of actively controllable components and keeps the motor vehicle in the driving corridor or on the movement trajectory by means of the actively controllable components.

[0013] The invention is explained in more detail below using an exemplary embodiment in conjunction with the accompanying drawing. The drawing shows: Fig. 1 a schematic representation of a vehicle with an environmental sensor system for detecting objects in the environment of the vehicle; Fig. 2 a schematic representation of a driver assistance system; Fig. 3 a block diagram of the safety device according to the invention and Fig. 4 a schematic representation of corridors suitable for escape routes.

[0014] In the context of the present invention, “steering wheel” represents all conceivable human-machine interfaces that the driver can operate in the sense of steering and controlling the motor vehicle, such as switch inputs, a joystick or a touchpad as well as externally transmitted control commands.

[0015] The terms signal quality and data quality are largely used synonymously.

[0016] In the following, we will first generally discuss Fig. 1 and Fig. 2 a safety device for motor vehicles is explained and illustrated by the Fig. 3 and Fig. 4 an embodiment of the invention is explained in more detail.

[0017] In Fig. 1 shows, by way of example, a four-wheeled, two-axle vehicle 1 which has an environmental sensor system 2 with which objects O in the vicinity of the vehicle can be detected, in particular other motor vehicles moving in the same or an adjacent lane to the side and / or in front of the vehicle 1. However, static or nearly static objects such as trees, pedestrians or roadway markings can also be considered as objects O. By way of example, an environmental sensor system 2 is shown with a detection range 3 which encompasses a solid angle in front of, next to or behind the vehicle 1, in which an object O is shown by way of example. The environmental sensor system 2 is, for example, a LIDAR sensor (Light Detection and Ranging), which is known per se to those skilled in the art. However, other environmental sensors such as radar sensors or optical camera systems can also be used.Furthermore, information about the surroundings can be determined using so-called car-to-X communication. This refers to the transmission of surroundings information from other vehicles or from other detection points to vehicle 1. The surroundings sensor system 2 measures the distances d to the detected points of an object as well as the angles φ between the connecting lines to these points and the central longitudinal axis of the vehicle, as shown in . Fig. 1 is illustrated by way of example for a point P of the object O. The fronts of the detected objects facing the vehicle 1 are composed of several detected points, to which the sensor signals are transmitted, which establishes correlations between points and the shape of an object and determines a reference point for the object O. The center of the object O or the center of the detected points of the object can be selected as the reference point, for example. In contrast to a radar sensor (Doppler effect), the speeds of the detected points and thus the speed of the detected objects cannot be measured directly using the LIDAR environmental sensor 2. They are calculated from the difference between the distances measured in successive time steps in a cyclically operating object recognition unit 21.In a similar way, the acceleration of the objects can in principle be determined by deriving their positions twice.

[0018] Fig. Figure 2 shows a schematic representation of a driver assistance system, the components of which, with the exception of sensors, actuators and other hardware, are preferably designed as software modules that are executed within the vehicle 1 by means of a microprocessor. As in Fig. 2, the object data is transmitted in the form of electronic signals within the schematically illustrated driver assistance system to a decision-making device 22. In the decision-making device 22, an object trajectory is determined in block 23 based on the information about the object O. Furthermore, a movement trajectory of the vehicle 1 is determined in block 24 based on information about the driving dynamics state of the vehicle 1, which is determined with the aid of further vehicle sensors 25. In particular, the vehicle speed, which can be determined, for example, with the aid of wheel speed sensors, the steering angle δ measured by a steering angle sensor at the steerable wheels of the vehicle 1, the yaw rate and / or the lateral acceleration of the vehicle 1, which are measured by means of corresponding sensors, are used.In addition, it is possible to calculate or estimate model-based variables from the dynamic driving conditions of the vehicle measured by the vehicle sensors 25. An indication of the coefficient of friction between the tires of the vehicle 1 and the road surface is also obtained from the vehicle sensors or from the road surface condition. This indication of the coefficient of friction is determined in particular by the brake control system. Then, in the decision device 22 within the block 26, a check is carried out as to whether the motor vehicle 1 is on a collision course with one of the detected objects O. If such a collision course is determined and the collision time, also determined in the decision device 22, i.e. the time until the determined collision with the object O, falls below a certain value, a trigger signal is transmitted to a path specification device 27.The trigger signal initially causes an evasive path, i.e., a movement trajectory, to be calculated within the path specification device. Then, based on the determined evasive path or movement trajectory, a starting point for the evasive maneuver is determined, at which point the evasive maneuver must be initiated in order to just barely avoid object O. These steps are preferably repeated in time increments until there is no longer any risk of collision due to course changes of object O or vehicle 1, or until vehicle 1 reaches the starting point for an evasive maneuver. If this is the case, the evasive path or parameters representing this path are transmitted to a steering / brake actuator controller 28.

[0019] With the help of the environmental data from the environmental sensor system 2, it is recognized whether an intervention is necessary and sensible. In addition, it is recognized how reliably the environmental sensor system 2 can assess the situation and thus what signal quality the environmental data has. The basic idea of ​​the present invention is that, depending on the criticality of the driving situation and the signal quality of the environmental data, an evasive action recommendation is issued to the driver or evasive action support is provided to the driver or an autonomous evasive action is carried out, whereby a more dominant measure is taken the more critical the driving situation and the better the signal quality of the environmental data. If the vehicle can evade safely because the environmental sensor system 2 has detected the situation reliably and accurately enough, an autonomous evasive action is carried out.If the uncertainty and thus the danger of an evasive maneuver is too high, support is provided for an evasive maneuver initiated by the driver.

[0020] In Fig. 3 shows the schematic structure of the safety device according to the invention. The idea here is to network the various sensor units 2, 20, 30, 40. A data fusion is carried out using the available data from the sensor units 2, 20, 30, 40. Data fusion is the merging and completion of incomplete data sets for data cleansing. In this process, several partially incomplete data sets must be combined in order to increase the signal quality of the surroundings data and to obtain a complete picture of the surroundings. Before the data sets from two sensor units 2, 20, 30, 40 can be fused, they must be brought into a common data schema. This process is also called data schema integration. Through this data fusion, it is possible to obtain information about the surroundings of the motor vehicle 1 that has better signal quality. A better signal quality orData quality ensures more accurate and faster calculation of collision risk. As explained in more detail below, data fusion also takes place to obtain improved information on environmental conditions, vehicle condition, and driver input data.

[0021] At least one sensor unit 2 is used to record the environmental conditions. This so-called environmental sensor system 2 is formed, as already mentioned, from a radar, lidar, or video camera system, or from a combination of the aforementioned systems. The information obtained with the help of at least one of these sensor units 2 is combined with map information, GPS data, and information obtained with the help of car-to-X communication within an evaluation unit 4 for data fusion of the environmental data. After the data fusion, the improved environmental data is evaluated to detect objects O. The position and movement of the object O is transmitted to a driving safety coordinator 6.This driving safety coordinator 6 determines permissible driving corridors K1, K2, K3, Kn based on driving physics limits and taking environmental data into account, thus ensuring the operational safety of vehicle 1 predictively and situationally by designing the driving corridors K1, K2, K3, Kn in such a way that a combined braking / evasive maneuver or a braking maneuver is performed. The driving corridors K1, K2, K3, Kn are then defined using... Fig. 4 is explained in more detail.

[0022] How Fig. 3, at least one further sensor unit 20 is used to detect the environmental condition. This at least one sensor unit 20 for detecting the environmental condition is formed by a rain sensor, a thermocouple, and / or a camera system. Taking into account the tire characteristic curve of the vehicle tires used, a data fusion is carried out in the evaluation unit 24 from the determined environmental condition data, and in step 25, a friction coefficient indication between the tire and the road surface is determined from the adjusted environmental condition data. This determination of the friction coefficient indication is carried out, for example, based on knowledge of the road surface condition. This determined friction coefficient indication is also forwarded to the driving safety coordinator 6.

[0023] At least one further sensor unit 30 serves to detect a vehicle condition. This at least one sensor unit 30 for vehicle condition detection is formed from a wheel speed sensor, a lateral acceleration sensor, a longitudinal acceleration sensor, or a yaw rate sensor. A combination of the aforementioned sensors is also possible. The sensor unit 30 for vehicle condition detection is also called a vehicle condition observer. In an evaluation unit 34 assigned to this vehicle condition observer, the vehicle condition data are combined with the determined friction coefficient indication in the sense of data fusion. As a result of this measure, the vehicle condition is calculated in step 35 and output to the driving safety coordinator 6.

[0024] How Fig. 3, at least one further sensor unit 40 is provided for detecting the driver's instructions and for outputting driver's instruction data. This at least one sensor unit 40 for detecting the driver's instructions is formed by a steering angle sensor, a pedal angle sensor for the brake pedal and / or the accelerator pedal, and / or by a direction indicator sensor. The direction indicator sensor is also colloquially referred to as a turn signal. The information includes whether the driver intends to turn left or right. The vehicle status data just determined is fed to the associated evaluation unit 44, and a data fusion is performed from this data together with the driver's instruction data. Since the data fusion cleanses the data by merging and completing incomplete data sets, a precise driver target course is calculated in step 45 and output to the driving safety coordinator 6.The position and movement of object O, as well as the determined friction coefficient indication, are transmitted to the driving safety coordinator 6. The driving safety coordinator 6 also receives the vehicle status and the driver's target course. From this data, a permissible driving corridor K1, K2, K3, K4 to Kn is determined. To illustrate the permissible driving corridors K1, K2, K3, and K4, . Fig. 4 the own vehicle 1 and the object O located in the direction of travel. The driving corridors K1, K3 shown in this example are situationally and predictively determined and are located within the predicted clear travel area to the left and right of object O. Corridor K2 designates an area in front of object O with no evasive path if emergency braking is sufficient to avoid a collision with object O. This means that the driving safety coordinator 6 initiates emergency braking if the permissible driving corridors K1 and K3, Kn do not provide any evasive path when the risk of collision is high. In this case, the driving corridor K2 is provided as the braking distance.

[0025] In order to keep vehicle 1 in the permitted driving corridors K1, K2, K3 to Kn, Fig. 3 explains in more detail how the driving safety coordinator 6 works. As already mentioned, the position and movement of the object(s) O and the determined friction coefficient indication are transmitted to the driving safety coordinator 6. In addition, the driving safety coordinator 6 receives the vehicle status and the driver's target course. From this data, a permissible driving corridor K1, K2, K3 to Kn is determined, and a target course calculation for the host vehicle 1 is carried out. In order to keep the vehicle 1 within the permissible corridor K1, K2, K3 to Kn, active components 9 are controlled such that the driver's input is limited to the available corridor K1, K2, K3 to Kn. These actively controllable components 9 are located in the chassis, driveline, or in a human-machine interface, such as the brake pedal, drive motor, steering, transmission, dampers, stabilizer, or direction indicators.Specifically, the driving safety coordinator 6 controls the actively controllable components 9 in such a way that a counterforce is generated on the accelerator pedal or an intervention in the drive motor, an intervention in the drive train, or a braking intervention is carried out in order to keep the vehicle within the driving corridor K1, K2, K3 to Kn. Alternatively or additionally, the actively controllable components 9 are controlled in such a way that an additional steering torque and / or an additional steering angle or a wheel-specific braking intervention is generated to generate a yaw moment. This control is also suitable for keeping the vehicle within the driving corridor K1, K2, K3 to Kn. In a special embodiment, each measure can be overridden by the driver, so that the driver retains control over his vehicle 1.

[0026] How Fig.3, the driving safety coordinator 6 evaluates the determined data with regard to the criticality of the driving situation and, if necessary, issues a warning to the driver and / or the environment. This environmental warning 8 can be issued visually, acoustically, or with the aid of car-to-X communication. Using car-to-X communication, the environmental warning 8 can be issued both to the infrastructure and to other vehicles. The warning to the driver is issued via a human-machine interface 7, also called a human-machine interface (HMI for short). The warning to the driver can be haptic, acoustic, or optical. All controllable components of the human-machine interface 7 are suitable for this purpose, such as a counterforce on the accelerator pedal or a vibration of the steering wheel. Warning lights and acoustic warning tones are also suitable for issuing a warning to the vehicle driver.

[0027] The position and movement of object O, as well as the determined friction coefficient indication, are thus transmitted to the driving safety coordinator 6. The driving safety coordinator 6 also receives the vehicle status and the driver's target course. From this data, a permissible driving corridor or an optimal movement trajectory is determined. The driving corridor or movement trajectory is determined situationally and predictively. The driving corridor or movement trajectory is located within the predicted clear travel area to the left and right of object O. To keep the vehicle 1 within the permissible corridor or on the optimal movement trajectory, active components 9 are controlled in such a way that the driver's input is limited to the available driving corridors K1, K2, K3, Kn or the optimal movement trajectory.These actively controllable components 9 are located in the chassis, drive, or in a human-machine interface, such as the brake pedal, drive motor, steering, transmission, dampers, stabilizer, or direction indicators. Specifically, the driving safety coordinator 6 controls the actively controllable components 9 such that a counterforce is generated on the accelerator pedal or an intervention in the drive motor, an intervention in the drive train, or a braking intervention is carried out in order to keep the vehicle within the driving corridor or on the movement trajectory. Alternatively or additionally, the actively controllable components 9 are controlled such that an additional steering torque and / or an additional steering angle or a wheel-specific braking intervention is generated to generate a yaw moment. This control is also suitable for keeping the vehicle within the driving corridors K1, K2, K3, Kn or on the movement trajectory.In the case of an evasive action recommendation and evasive action assistance, each measure can be overridden by the driver, so that the driver retains control over his vehicle 1.

[0028] As already mentioned, the key idea behind the invention is that, depending on the criticality of the driving situation and the signal quality of the environmental data, either an evasive action recommendation is issued to the driver, evasive action assistance is provided to the driver, or autonomous evasive action is initiated. The more critical the driving situation is and the better the signal quality of the environmental data, the more dominant the measure taken. In this context, one also speaks of the rigidity of the evasive action function. The rigidity of the evasive action refers to the control or dominance over the vehicle. The basic idea is based on the realization that the more critical the driving situation is and the better the signal quality of the environmental data, the greater the rigidity of the evasive action function.The driving safety coordinator 6 assumes control of the vehicle the more critical the driving situation becomes and the better the signal quality or data quality of the surrounding data is. The driving safety coordinator 6 provides evasive action support to the driver if the signal quality of the surrounding data is low. The driving safety coordinator 6 issues an evasive action recommendation to the driver and supports the evasive action if the signal quality of the surrounding data is medium. If the signal quality of the surrounding data is sufficiently good, the driving safety coordinator 6 performs an autonomous evasive action.

[0029] If the driver initiates an evasive maneuver before the evasive function reacts, the driver will always receive assistance once the last possible braking point to bring the vehicle to a safe stop before object O (the so-called "last point to brake") has already passed. Assistance is only provided before the last possible braking point (last point to brake) if a dynamically unstable situation would arise without assistance.

[0030] The inventive idea of ​​selecting a more dominant measure from evasive recommendation, evasive assistance and autonomous intervention depending on the criticality of the driving situation and the signal quality of the environmental data is explained in more detail below using four examples: Example 1:

[0031] The surroundings sensor system 2 detects that an evasive maneuver is necessary. However, the system determines that the evasive maneuver can take place entirely within the vehicle's lane. Therefore, an automatic evasive maneuver is initiated, even without the driver having initiated it. Example 2:

[0032] The surroundings sensor system 2 detects that an evasive maneuver is necessary. It also detects that there are clear evasive areas, such as restricted areas on the roadway that are not supposed to be used. These evasive areas are sufficient for the evasive maneuver, so an automatic evasive maneuver is initiated, even without the driver's initiation. Example 3:

[0033] The surroundings sensor system 2 detects that an evasive maneuver is necessary. However, this requires the vehicle to move into the adjacent lane. Additional surroundings sensor system 2 detects that this lane is clear and that no vehicle is approaching from behind. Since this is a highway and therefore no oncoming traffic is expected, an automatic evasive maneuver is initiated, even without the driver initiating it. Example 4:

[0034] The surroundings sensor system 2 detects that an evasive maneuver is necessary. However, this requires the driver to swerve into the adjacent lane. It's a highway, which is detected, for example, by electronic maps, so oncoming traffic is not expected. However, since there's no surroundings sensor system 2 that can detect whether a vehicle is approaching from behind, the system doesn't perform an autonomous evasive maneuver, but rather issues a warning. If the driver initiates the evasive maneuver, the function supports them.

Claims

[1] Method for the safe operation of a motor vehicle (1) with at least one sensor unit (2) for detecting the environmental conditions and for outputting environmental data, an evaluation unit (4) for evaluating the environmental data and an evaluation unit (5) for detecting free spaces and objects (O), their position and movement, as well as with a driving safety coordinator (6) which determines the risk of collision of the motor vehicle (1) with an object (O) on the basis of a risk assessment, wherein the driving safety coordinator (6) issues an evasive action recommendation to the driver or evasive action support for the driver or carries out an autonomous evasive action intervention based on the criticality of the driving situation and the signal quality of the environmental data, wherein the driving safety coordinator (6) takes a more dominant measure the higher the criticality of the driving situation and the better the signal quality of the environmental data,whereby the signal quality of the environmental data is improved by means of a data fusion of further data, and, a further sensor unit (20) detects the environmental condition and outputs environmental condition data to an evaluation unit (24) for data fusion of the environmental data with the environmental condition data to determine a friction coefficient indication, and a further sensor unit (30) detects the vehicle condition and outputs vehicle condition data to an evaluation unit (34) for data fusion of the vehicle condition data with the friction coefficient indication and the driver specification data to determine the driving condition. [2] Method according to claim 1, characterized by that the driving safety coordinator (6) assumes control over the motor vehicle, the higher the criticality of the driving situation and the better the signal quality of the environmental data, whereby the driving safety coordinator (6) - provides evasive assistance to the driver if the signal quality of the surrounding data is low, - issues an evasive action recommendation to the driver and supports the evasive action if the signal quality of the surrounding data is medium and - carries out autonomous evasive intervention if the signal quality of the surrounding data is sufficiently good. [3] Method according to claim 1 or 2, characterized by that a further sensor unit (40) detects the driver specifications and outputs driver specification data to an evaluation unit (44) for data fusion of the driver specification data with the vehicle status data to determine the driver target course. [4] Method according to claim 1 or 2, characterized by that the driving safety coordinator (6) issues a visual, acoustic and / or haptic warning to the driver before carrying out an autonomous evasive intervention. [5] Method according to one of the preceding claims, characterized by that the driving safety coordinator (6) predictively and situationally determines at least one permissible driving corridor (K1 to Kn) and / or an optimal movement trajectory to ensure operational safety and limits the driver's input to the driving corridor by means of actively controllable components (9) and keeps the motor vehicle (1) in the driving corridor (K1 to Kn) or on the movement trajectory by means of the actively controllable components (9).

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