Method and device for longitudinal guidance of a motor vehicle

Abstract

Method for lateral guidance of a motor vehicle by means of an assistance system (2), wherein lane boundaries (10) are detected by means of at least one environmental sensor (3) and / or swarm data, wherein the assistance system (2) generates steering instructions for a steering system based on the data of the at least one environmental sensor (3) and / or the swarm data in order to keep the motor vehicle on a target trajectory (8) of the assistance system (2), wherein the driver can adjust the target trajectory (8), wherein the assistance system (2) then generates steering instructions for the steering system depending on the data of the at least one environmental sensor (3) and / or the swarm data in order to keep the motor vehicle on this adjusted target trajectory (11), wherein areas (ODD) are detected in which the driver is permitted to remove their hands from a steering handrail, wherein at least one sensor (4) is used to detectwhether the driver has removed their hands from the steering handles, wherein the assistance system (2) switches from the adapted target trajectory (11) to a target trajectory (8) of the assistance system (2) when no hands are detected on the steering handles within an area (ODD) and transmits corresponding steering instructions to the steering system, or that upon entering an area (ODD), the system automatically switches from the adapted target trajectory (11) to a target trajectory (8) of the assistance system (2), wherein the driver can adjust the target trajectory (8) of the assistance system (2) or an adapted target trajectory (11) within the area (ODD) if they have their hands on the steering handles, wherein at least one adjustment of the target trajectory (8, 11) within an area (ODD) differs in at least one parameter from an adjustment of the target trajectory (8) outside the area (ODD). differs.,

Description

[0001] The invention relates to a method and a device for the lateral guidance of a motor vehicle.

[0002] Various methods for assisted or autonomous lateral guidance of a motor vehicle are known, such as lane keeping assistance systems. These systems use environmental sensors to detect lane boundaries and generate steering torque to keep the vehicle in its lane. Typically, the system attempts to keep the vehicle in the center of the lane, although this can be modified when cornering, for example, by steering more sharply inwards into the curve. Furthermore, it is already known that the driver can adjust this target trajectory within certain limits, so that the target trajectory is not in the center of the lane, but offset by a few centimeters to the left or right of it.

[0003] Furthermore, it has already been proposed to define specific areas where greater assistance should be enabled. Such areas are also known as ODDs (Operational Design Domains). These are typically characterized by clearly recognizable lane markings and a relatively straight and unobstructed road layout. Within such an ODD, the driver is permitted to take their hands off the steering wheel, at which point the system takes over lateral control completely autonomously. Driver monitoring is then carried out via an alternative system, such as an in-car driver monitoring system.

[0004] From DE 10 2021 130 174 A1, a method for the lateral guidance of a motor vehicle by means of a driver assistance system is known, wherein lane boundaries are detected by means of at least one environmental sensor, and wherein the driver assistance system generates steering instructions for a steering system based on the data from the at least one environmental sensor to keep the vehicle on a target trajectory of the assistance system. Furthermore, areas in which the driver is permitted to remove their hands from the steering handles are detected. At least one sensor detects whether the driver has removed their hands from the steering handles, and if no hands are detected on the steering handles within a certain area, the assistance system switches to a target trajectory of the assistance system and transmits corresponding steering instructions to the steering system.When entering an area, the assistance system automatically switches to a target trajectory.

[0005] US patent 2009 / 0299573 A1 discloses a driver assistance system in which the driver can adjust a target trajectory within the lane, so that, for example, the vehicle does not drive in the middle of a lane, but offset to a lane boundary.

[0006] A similar driver assistance system is known from DE 10 2012 214 847 A1.

[0007] Driver assistance systems are known from DE 10 2021 206 886 A1 and DE 10 2021 205 200 A1, where lateral guidance of a motor vehicle is carried out using swarm data.

[0008] The invention is based on the technical problem of providing a method to integrate such hands-off driving into existing methods, as well as creating a suitable device.

[0009] The solution to the technical problem is achieved by a method having the features of claim 1 and a device having the features of claim 4. Further advantageous embodiments of the invention are set forth in the dependent claims.

[0010] The method for lateral guidance of a motor vehicle is achieved by means of an assistance system, wherein lane boundaries are detected using at least one environmental sensor and / or swarm data. Based on the data from the at least one environmental sensor and / or the swarm data, the assistance system generates steering instructions for a steering system to keep the motor vehicle on a target trajectory defined by the assistance system. The steering instructions can be, for example, curves, rack positions, or steering angles, which are then implemented by the steering system. The environmental sensor system preferably comprises at least one camera. Additionally or alternatively, the environmental sensor system can also include radar, lidar, and / or ultrasonic sensors.Furthermore, the driver can adjust the target trajectory, whereby the assistance system then generates steering instructions for the steering system based on data from at least one environmental sensor and / or swarm data, in order to keep the vehicle on this adjusted target trajectory. This adjustment can be made in various ways, which can also be made available to the driver as alternatives. For example, the driver can enter the adjustment alphanumerically or using a button. Alternatively, the adjustment can be learned by having the driver maintain the vehicle on the desired adjusted target trajectory for a specified time or distance, contrary to the assistance system's target trajectory.

[0011] Furthermore, areas are recorded in which the driver is permitted to remove their hands from the steering wheel. These areas may be stored on a digital map or provided by a server. Additionally, environmental sensors may be used to detect these areas. At least one sensor also detects whether the driver has removed their hands from the steering wheel. This sensor could be, for example, a capacitive steering wheel or an interior camera. Alternatively, hands-on / hands-off detection can also be performed using data from a steering torque sensor.

[0012] If, within such an area (ODD), the assistance system detects that the driver has taken their hands off the steering wheel, it switches from the adapted target trajectory to a target trajectory of the assistance system itself. This allows the assistance system to steer towards a trajectory that is more manageable for automated driving. It should be noted that this target trajectory of the assistance system does not necessarily have to be the previously mentioned target trajectory. For example, the target trajectory of the assistance system within the area could be a target trajectory that depends on the adapted target trajectory. The switchover then preferably results in the assistance system adjusting the trajectory within a predetermined time (e.g., 5 seconds) or a predetermined distance (e.g., 100 km).100 m) adjusts the steering instructions so that the vehicle is steered from the adapted target trajectory to the target trajectory of the assistance system. This smooth transition provides a high level of driver comfort and results in less irritation for the driver due to the change in the target trajectory.

[0013] Alternatively, it can be provided that the assistance system automatically switches to a target trajectory of the assistance system when entering the area, regardless of whether the driver has taken their hands off the steering handle or not.

[0014] The advantage of the first alternative is that the driver is not overridden and can continue on his adapted target trajectory for as long as possible.

[0015] The advantage of the second alternative is the simple and quick switching.

[0016] The switchover occurs according to the first alternative, i.e., only if a hands-off has been detected.

[0017] Furthermore, within the area, the driver can adjust the target trajectory of the assistance system or a modified target trajectory if they have their hands on the steering handle.

[0018] In this context, at least one adjustment of the target trajectory within a given range differs in one parameter from an adjustment of the target trajectory outside the range. For example, the adjustment from a first adjusted target trajectory to a second adjusted target trajectory can be the same as outside the range, whereas the adjustment from a target trajectory of the assistance system to a new adjusted target trajectory after a hands-off driving phase is different. For instance, the driver must steer against the target trajectory of the assistance system for a longer period or distance before it is adopted as the adjusted target trajectory. The reverse is also possible, meaning the required time or distance is shorter.

[0019] In one embodiment, a modified target trajectory is deleted after switching to a target trajectory of the assistance system. The advantage is that this prevents confusion for the driver if they had only modified the target trajectory situationally (e.g., due to a specific traffic situation). This could lead to the driver being surprised when, after driving hands-off on the assistance system's target trajectory, the system switches back to the modified target trajectory, even though the original traffic situation no longer exists.

[0020] However, it is also possible to save the adjusted target trajectory and automatically reactivate it after the hands-off driving phase, for example because the adjusted target trajectory is a target trajectory generally preferred by the vehicle (e.g., always driving slightly to the right outside the center of the lane).

[0021] It may be possible to provide the driver with a choice, allowing them to select whether the adjusted target trajectory should be discarded or deleted, or saved. This allows the driver to configure the desired behavior according to their preferences.

[0022] In a further embodiment, if it is detected outside a certain area that the driver has removed their hands from the steering handles, the adapted target trajectory is maintained, and the driver is prompted to grasp the steering handles. Should the driver fail to place their hands back on the steering handles after a predetermined time, the system can switch to a target trajectory of the assistance system and prepare for an emergency stop.

[0023] The device for the lateral guidance of a motor vehicle has at least one assistance system and at least one environmental sensor and / or a swarm data database, or can access such data. For example, the swarm data is stored in a cloud server, with the device retrieving the necessary swarm data for its current environment. The device is configured to detect lane boundaries based on the data from the at least one environmental sensor and / or the swarm data, and the assistance system is configured to generate steering instructions for a steering system based on the data from the at least one environmental sensor and / or the swarm data in order to keep the motor vehicle on a target trajectory defined by the assistance system.Furthermore, the device is designed such that the driver can adjust the target trajectory, whereby the assistance system then generates steering instructions for the steering system based on data from at least one environmental sensor and / or swarm data in order to keep the vehicle on this adjusted target trajectory. The device is further designed to detect areas in which the driver is permitted to remove their hands from the steering handles (hands-off or hands-free), and the device includes at least one sensor designed to detect whether the driver has removed their hands from the steering handles.The assistance system is further designed such that, if no hands are detected on the steering handles within a certain area, it switches from the adapted target trajectory to a target trajectory of the assistance system and transmits corresponding steering instructions to the steering system. Alternatively, it can be provided that upon entering a certain area, the system automatically switches from the adapted target trajectory to a target trajectory of the assistance system, even if the driver has their hands on the steering handles.

[0024] Regarding the further design of the device, full reference is made to the preceding explanations.

[0025] The invention is explained in more detail below with reference to a preferred embodiment. The figures show: Fig. 1 a schematic block diagram of a device for the lateral guidance of a motor vehicle, Fig. 2 a schematic, exemplary representation of a target trajectory of an assistance system and an adapted target trajectory of a motor vehicle driver and Fig. 3. A flowchart of a procedure for the lateral guidance of a motor vehicle.

[0026] In the Fig. Figure 1 is a highly schematic block diagram of a device 1 for the lateral guidance of a motor vehicle. The device 1 comprises an assistance system 2, at least one environmental sensor 3, at least one sensor 4 for detecting whether the driver has their hands on a steering handle (hands-on / hands-off detection), a unit 5 for position determination, and an input unit 6. Also shown is a database 7 in which information about areas (ODD) is stored in which the driver is permitted to remove their hands from the steering handle. The assistance system 2 is configured to generate steering instructions to guide the motor vehicle along a target trajectory 8 (see Figure 1). Fig. 2) to maintain the assistance system 2. For this purpose, the assistance system 2 generates control commands S, which are then implemented by a steering system 9 of the motor vehicle. The control commands S are, for example, a curve or a rack position. The functionality of the device 1 will now be explained using the Fig. Section 2 will be explained in more detail, using two lanes FS1 and FS2 of a motorway as examples. The device 1 detects lane boundaries 10 using at least one environmental sensor 3. The vehicle (not shown) is located in the left lane FS1. The assistance system 2 is designed such that, depending on the detected lane boundaries 10, a target trajectory 8 is calculated for the vehicle, which, for example, lies in the center of lane FS1. The assistance system 2 then generates steering torques to keep the vehicle on this target trajectory 8. Furthermore, the driver can transmit an adjusted target trajectory 11 to the assistance system 2 via the input unit 6. This adjusted target trajectory 11 runs a distance further to the left, specified by the driver, meaning the vehicle travels closer to the left lane boundary 10.The transmission of the adapted target trajectory 11 can be carried out in various ways. For example, the adapted target trajectory 11 is taught by the driver actively steering the vehicle towards the adapted target trajectory 11 against the assistance system 2 for a predetermined time or distance. Alternatively, the driver can enter the distance and direction (left or right) to the target trajectory 8 of the assistance system 2 via the input unit 6. If the assistance system 2 is active, it then generates steering instructions to keep the vehicle on the adapted target trajectory 11.

[0027] Furthermore, sensor 4 performs hands-on / hands-off detection, i.e., whether the driver's hands are on the steering handles or not. If the driver removes their hands from the steering handles, assistance system 2 prompts them (for example, via an acoustic and / or visual warning) to grip the steering handles again, while assistance system 2 continues to attempt to maintain the adapted target trajectory 11. If the driver still has not taken over after a predetermined time (e.g., 10 seconds), assistance system 2 switches to the target trajectory 8 and, if necessary, initiates an emergency stop.

[0028] In certain areas ODD (in Fig. 2 (indicated by two horizontal lines), which are stored in database 7, indicate that hands-off operation is permitted. Database 7 can be stored in the vehicle's memory. Alternatively, it can be provided by a service provider and retrieved by the vehicle. Using the data from unit 5, the vehicle can locate itself and determine whether it is approaching such an ODD area. The driver can then be informed accordingly, for example, visually and / or audibly, so that they know hands-off operation is permitted. If the driver then takes their hands off the steering wheel, this is detected by sensor 4, and the assistance system 2 then switches to the target trajectory 8 of the assistance system 2 for the vehicle.At the end of the ODD section, the driver is prompted to resume steering control, although the target trajectory 8 of assistance system 2 can be maintained. The target trajectory 8 followed in hands-off mode within the ODD section is preferably the original target trajectory 8 of assistance system 2, but this is not mandatory. A modified target trajectory of assistance system 2, which takes into account the driving preferences of the adapted target trajectory 11, can also be followed.

[0029] Device 1 therefore behaves differently depending on whether a hands-off detection is detected inside or outside the ODD area.

[0030] Furthermore, it may be provided that if the driver has initially taken his hands off the steering handle in the ODD area (switching to target trajectory 8), then when he grasps the steering handle again within the ODD area, the target trajectory 8 can be adjusted again, so that the driver can drive along an adjusted target trajectory 11 with his hands on the steering handle.

[0031] In the Fig. Figure 3 shows a flowchart of the procedure. In the first step, S1 checks whether the driver has removed their hands from the steering wheel. If this is confirmed, the second step, S2, checks whether the vehicle is in an ODD area where the driver is permitted to remove their hands from the steering wheel. If this is the case, the third step, S3, switches from an adapted target trajectory 11 to a target trajectory 8 of the assistance system 2 (see also Fig.2) In a fourth step, S4, it is checked whether the vehicle is still within the ODD area. If this is not the case, in a fifth step, S5, the driver is prompted to resume steering. If, however, it was determined in the second step, S2, that the vehicle is not within an ODD area where it is permitted to remove the hands from the steering handles, the driver is prompted in a sixth step, S6, to return to the steering handles. In a seventh step, S7, it is checked whether the driver has complied with the prompt. If so, the procedure returns to the first step, S1. Otherwise, in an eighth step, S8, the system switches to the target trajectory 8 of the assistance system 2, and in a ninth step, S9, an emergency stop is prepared. Reference symbol list 1 Device 2 Assistance systems 3 Environmental sensors 4 Sensors 5 units 6 Input unit 7 Database 8 Target trajectory 9 Steering system 10 lane markings 11 adjusted target trajectory S control command FS1, FS2 lanes ODD area S1 - S9 steps

Claims

[1] Method for lateral guidance of a motor vehicle by means of an assistance system (2), wherein lane boundaries (10) are detected by means of at least one environmental sensor (3) and / or swarm data, wherein the assistance system (2) generates steering instructions for a steering system based on the data of the at least one environmental sensor (3) and / or the swarm data in order to keep the motor vehicle on a target trajectory (8) of the assistance system (2), wherein the driver can make an adjustment of the target trajectory (8), wherein the assistance system (2) then generates steering instructions for the steering system depending on the data of the at least one environmental sensor (3) and / or the swarm data in order to keep the motor vehicle on this adjusted target trajectory (11), wherein areas (ODD) are detected in which the driver is permitted to take his hands off a steering hand, wherein at least one sensor (4) is used to detect,whether the driver has removed their hands from the steering handles, wherein the assistance system (2) switches from the adapted target trajectory (11) to a target trajectory (8) of the assistance system (2) when no hands are detected on the steering handles within an area (ODD) and transmits corresponding steering instructions to the steering system, or that upon entering an area (ODD), the system automatically switches from the adapted target trajectory (11) to a target trajectory (8) of the assistance system (2), wherein the driver can adjust the target trajectory (8) of the assistance system (2) or an adapted target trajectory (11) within the area (ODD) if they have their hands on the steering handles, wherein at least one adjustment of the target trajectory (8, 11) within an area (ODD) differs in at least one parameter from an adjustment of the target trajectory (8) outside the area (ODD). differs., [2] Method according to claim 1, characterized by , that an adapted target trajectory (11) is deleted after switching to a target trajectory (8) of the assistance system (2). [3] Method according to any of the preceding claims, characterized by , that if outside an area (ODD) it is detected that the driver has removed his hands from the steering handles, the adjusted target trajectory (11) is maintained, prompting the driver to grasp the steering handles. [4] Device (1) for the lateral guidance of a motor vehicle, wherein the device (1) has or can access at least one assistance system (2) and at least one environmental sensor (3) and / or a database of swarm data, wherein the device (1) is configured to detect lane boundaries (10) based on the data from the at least one environmental sensor (3) and / or the swarm data, wherein the assistance system (2) is configured to generate steering instructions for a steering system based on the data from the at least one environmental sensor (3) and / or the swarm data in order to keep the motor vehicle on a target trajectory (8) of the assistance system (2), wherein the driver of the motor vehicle can adjust the target trajectory (8), and wherein the assistance system (2) then generates steering instructions for the steering system depending on the data from the at least one environmental sensor (3) and / or the swarm data,to keep the motor vehicle on this adapted target trajectory (11), wherein the device (1) is further configured to detect areas (ODD) in which the driver is permitted to remove his hands from a steering handle, wherein the device (1) has at least one sensor (4) configured to detect whether the driver has removed his hands from the steering handle, wherein the assistance system (2) is configured such that, when no hands are detected on the steering handle within an area (ODD), the adapted target trajectory (11) is switched to a target trajectory (8) of the assistance system (2) and corresponding steering instructions are transmitted to the steering system, or that, upon entering an area (ODD), the adapted target trajectory (11) is automatically switched to a target trajectory (8) of the assistance system (2), wherein the assistance system (2) is configured such thatthat the driver, within the area (ODD), adjusts the target trajectory (8) of the assistance system (2) or an adapted target trajectory (11) when keeping their hands on the steering handle, wherein the assistance system (2) is designed such that at least one adaptation of the target trajectory (8, 11) within an area (ODD) differs in at least one parameter from an adaptation of the target trajectory (8) outside the area (ODD). [5] Device according to claim 4, characterized by , that the assistance system (2) is designed such that an adapted target trajectory (11) is deleted after switching to a target trajectory (8) of the assistance system (2). [6] Device according to one of claims 4 or 5, characterized by, that the assistance system (2) is designed such that, if outside an area (ODD) it is detected that the driver has removed his hands from the steering handle, the adapted target trajectory (11) is maintained, prompting the driver to grasp the steering handle.

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