METHOD FOR OPERATING A LANE GUIDE ASSISTANCE SYSTEM OF A VEHICLE, TAKING INTO ACCOUNT ENVIRONMENTAL CONDITIONS, LANE GUIDE ASSISTANCE SYSTEM AND VEHICLE

Description

[0001] The present invention relates to a method for operating a lane keeping assist system of a vehicle. Furthermore, the present invention relates to a lane keeping assist system for a vehicle. Finally, the present invention relates to a vehicle with such a lane keeping assist system.

[0002] Lane keeping assist systems for vehicles are well-known in the field. These systems, also known as steering and lane guidance assistants or active lane keeping assistants, primarily serve to keep the vehicle within its lane. Such a system uses environmental data from the vehicle's sensors to detect lane boundaries and markings. If these lane markings are detected with sufficient certainty, the system can be activated and steering interventions can be made to keep the vehicle within its lane. For example, these steering interventions can be such that the vehicle is kept centered within the lane.

[0003] In current technology, the availability of the lane guidance system is linked to various conditions. For example, a so-called debouncing time may be required, which specifies that the lane boundaries or road markings must be reliably detected for a predetermined period. Furthermore, it is known to adjust this debouncing time if the presence or detection of lane markings by existing environmental sensors changes frequently. For instance, lane markings may be detected and then disappear multiple times within a specific period, such as 30 seconds. This increase in the debouncing time serves to ensure continuous availability of the lane guidance system and to avoid frequent changes in state.

[0004] The technical problem inherent in the described state of the art is twofold: firstly, the overall availability of the lane guidance assistant is reduced because the debounce time temporarily prevents activation of the function. Secondly, this state of the art does not take into account current conditions or parameters that affect the lane guidance assistant's functionality. Therefore, optimal debounce time settings cannot be achieved, and the best possible availability of the function while maintaining a consistent operating state is not attained.

[0005] German patent application DE 10 2017 208 384 A1 discloses a method for operating a motor vehicle with a traffic jam assist system. The method involves the following steps: reading sensor data serving as input data for the traffic jam assist system, evaluating the sensor data to determine a value representative of the signal roughness of the sensor data, comparing this value with a threshold value, and generating a suppression signal to prevent the automatic activation of the traffic jam assist system if the value is greater than the threshold value.

[0006] The object of the present invention is to provide a solution for improving a lane guidance assistant of the type mentioned above in such a way as to increase availability and simultaneously improve reliability.

[0007] This problem is solved according to the invention by a method, by a lane guidance assistant, and by a vehicle with the features according to the independent claims. Advantageous embodiments of the present invention are specified in the dependent claims.

[0008] A method according to the invention serves to operate a lane guidance assistant for a vehicle. The method comprises receiving environmental data describing the vehicle's surroundings. Furthermore, the method includes detecting lane boundaries that define the lane in which the vehicle is currently located. The method also includes automatically performing steering interventions to keep the vehicle in the lane if the lane boundaries are detected for a predetermined debounce time. In addition, the method includes continuously determining environmental conditions, wherein the environmental conditions describe the vehicle's current location, the weather in the surrounding area, the current time of day, and / or the road type associated with the lane. Finally, the method includes adjusting the debounce time depending on the continuously determined environmental conditions.

[0009] The lane keeping assist system is designed to support the driver with steering tasks. Specifically, it helps keep the vehicle within its lane. The lane keeping assist system can also be referred to as a steering and lane guidance assistant, an active lane keeping assistant, or a steering assistant. It can include at least one environmental sensor to provide data about the vehicle's surroundings. This environmental sensor could be, for example, a camera. If the camera is used, the environmental data would be image data.

[0010] Lane boundaries can be detected in the environmental data. Specifically, the lane boundaries that define the lane the vehicle is currently in are detected. It may also be possible to detect lane boundaries of other or adjacent lanes. These lane boundaries can be road markings, such as solid, dashed, or broken lines. They can also be physical barriers, such as walls, guardrails, curbs, or similar features. Furthermore, lane boundaries can be defined by features like grass verges, gravel beds, or similar elements.

[0011] If the lane markings are reliably detected with a predetermined probability or certainty within the debounce time, the lane keeping assist function can be activated. This means that the lane keeping assist system provides steering interventions or a superimposed steering torque to keep the vehicle within the lane. For example, the lane keeping assist system can intervene directly in the vehicle's course via an active steering system. However, the steering torque or intervention provided by the lane keeping assist system can be overridden by the driver at any time by turning the steering wheel.

[0012] The lane guidance assistant function is intended to be activated only if the lane boundaries or road markings are detected with a predetermined certainty or probability for the duration of the predetermined debounce time. According to the present invention, it is now possible to adapt this debounce time to the current environmental conditions. These environmental conditions can describe, firstly, the current location or country in which the vehicle is currently situated. Furthermore, the environmental conditions can describe the weather in the vicinity of the vehicle. Alternatively or additionally, the environmental conditions can describe the current time of day or the lighting conditions in the vicinity of the vehicle. In addition, the environmental conditions can describe the type of road on which the lane is located.

[0013] The environmental conditions are intended to be continuously monitored. For example, they can be recorded at predetermined times or intervals. This allows the debouncing time to be adjusted to the changing environmental conditions. Based on these environmental conditions, the debouncing time can be adjusted. In this way, continuous availability of the lane guidance assistant can be achieved, and frequent changes between an active and a standby state of the lane guidance assistant can be avoided. Overall, this can increase user satisfaction and customer acceptance.

[0014] Preferably, a country-specific debounce time is determined based on the vehicle's current location, and the debounce time is adjusted accordingly. It is therefore preferred that the environmental conditions describe the vehicle's current location. In particular, the environmental conditions can describe the country in which the vehicle is currently located or being driven. It is specifically intended that different debounce times can be stored and retrieved for different countries or regions. For example, customer requirements and the conditions in different countries may necessitate a country-specific debounce time setting. For instance, shorter debounce times than the standard debounce time may be required for countries like China or the USA.In this system, the lane keeping assist or steering assist can switch to an active control state earlier if stable detection of lane markings and a suitable road surface are present. Overall, this allows the system to take into account the different requirements of customers in different countries, the condition of the roads, and similar factors.

[0015] In a further embodiment, the reliability of lane marking detection based on environmental data is determined using weather conditions and / or the current time of day. The debounce time is also preferably adjusted depending on the detection reliability. Weather conditions and / or weather data can be used to determine whether the detection of lane markings by the at least one environmental sensor is limited by the weather. This can occur, for example, in rain, snowfall, fog, or similar conditions. Precipitation, for instance, can impair lane marking detection by the environmental sensors. It can also be provided that precipitation, such as snow and / or ice, has accumulated on the lane, thus preventing or severely limiting the detection of the lane markings.Furthermore, a wet road surface can cause reflections which also impair the detection of road markings by the environmental sensor.

[0016] Based on the current time of day, the ambient lighting conditions can be determined. These conditions, or brightness levels, can also affect the detection of lane markings by the environmental sensor. For example, lane marking detection can be significantly impaired at dusk and at night. Strong sunlight can also considerably worsen lane marking detection. Overall, based on weather data and / or the current time of day, it can be determined whether lane marking detection by the environmental sensor is impaired compared to a defined normal state. This can then be taken into account when adjusting the debounce time.

[0017] In particular, the system is designed to increase the debouncing time if the detection reliability falls below a predetermined average value. The debouncing time is also increased in bad weather, which is determined by environmental data from at least one sensor or by a weather report. This poses a risk of unstable lane and lane marking detection, leading to fluctuating functionality and potentially incorrect vehicle control due to insufficient environmental data. The same applies to driving at dusk or at night.

[0018] Furthermore, it is advantageous to reduce the debouncing time if the road type is that of a motorway. Therefore, it is preferable to reduce the debouncing time on motorways, as stable and clearly visible lane markings or lane boundaries can be assumed there. The same applies to expressways, federal highways, and similar types of roads. In general, the road's condition and the usual or known presence of lane markings or lane boundaries can be considered. For example, digital map data or environmental data from other vehicles can be used to describe the quality of the lane markings. Additionally, the date of the road's construction or whether it has been resurfaced can be taken into account. Thus, the debouncing time can be ideally adapted to the current road type.

[0019] In another embodiment, environmental conditions are determined using environmental data, satellite-based position data, digital map data, and / or weather data. To determine environmental conditions, the environmental data or the sensor data from at least one environmental sensor can be used directly. This allows, for example, the detection of precipitation in the vicinity of the vehicle. It can also be determined whether precipitation has settled on the road surface. To determine the current weather, weather data can also be received from a corresponding transmitter, backend, or similar device. To determine the current time of day, data from a clock and / or a light sensor or similar device can be used. To determine the current position, the system can use a different type of sensor.To determine the vehicle's current location, digital map data and / or satellite-based positioning systems can be used. This allows for a reliable assessment of environmental conditions.

[0020] A lane guidance assistant according to the invention for a vehicle is configured to receive environmental data describing the vehicle's surroundings. Furthermore, the lane guidance assistant is configured to detect lane boundaries that define the lane in which the vehicle is currently located. Additionally, the lane guidance assistant is configured to perform automatic steering interventions to keep the vehicle in the lane if the lane boundaries are detected for a predetermined debouncing time. Finally, the lane guidance assistant is configured to continuously determine environmental conditions, wherein the environmental conditions describe the vehicle's current location, the surrounding weather, the current time of day, and / or the road type associated with the lane.Furthermore, the lane guidance assistant is designed to adjust the debounce time depending on the continuously determined environmental conditions.

[0021] The environmental data can be provided by at least one environmental sensor of the vehicle or the lane guidance system. This sensor could, for example, be a camera. Alternatively, the sensor could be an optical, infrared, or lidar sensor. The lane guidance system can also include a corresponding processing unit, which could be, for example, part of the vehicle's electronic control unit. A corresponding program or computer program can be run on this processing unit. In this way, the lane markings can be determined based on the environmental data.

[0022] Furthermore, the lane guidance assistant can include a receiver for receiving weather data, data from a backend system, or similar information. It can also be configured to have a satellite-based positioning system. The computer can then determine environmental conditions and adjust the debouncing time based on these continuously determined environmental conditions.

[0023] Furthermore, the lane guidance assistant can have a corresponding actuator by means of which steering interventions can be carried out or an additional steering torque can be provided.

[0024] A vehicle according to the invention comprises a lane guidance assistant according to the invention. The vehicle is designed in particular as a passenger car.

[0025] The preferred embodiments and their advantages presented with reference to the method according to the invention apply accordingly to the lane guidance assistant according to the invention as well as to the vehicle according to the invention.

[0026] The invention will now be explained in more detail with reference to preferred embodiments and the accompanying drawings. These show: Fig. 1 a schematic representation of a vehicle equipped with a lane keeping assist system; and Fig. 2 the vehicle according to Fig. 1 , which is located in a traffic lane.

[0027] Fig. 1 Figure 1 shows a vehicle 1, which in this case is a passenger car, in a top view. The vehicle 1 includes a lane keeping assistant 2, by means of which the vehicle 1 can be kept within a lane 6. The lane keeping assistant 2 includes a computing unit 3, which can, for example, be formed by at least one electronic control unit of the vehicle 1.

[0028] Furthermore, the lane guidance assistant 2 includes at least one environmental sensor 4. In the example shown, the lane guidance assistant 2 includes an environmental sensor 4, which is implemented as a camera. The environmental sensor 4 can provide environmental data or image data that describe the vehicle's surroundings 5. The lane guidance assistant 2 also includes a receiver 7, which can receive, for example, weather data. The receiver 7 can also receive data from a backend, the internet, a radio station, or similar sources. Additionally, the receiver 7 can receive data from a satellite-based positioning system. Instead of the example receiver 7, several individual receivers can also be used.

[0029] The computing unit 3 is further configured to control a steering system 8 of the vehicle 1, which is shown only schematically here. By controlling the steering system 8, a steering torque or steering intervention can be generated to keep the vehicle 1 in the lane 6 or the track. By controlling the steering system 8, steerable wheels 9 of the vehicle 1 can be steered and thus the lateral guidance of the vehicle 1 can be influenced.

[0030] Fig. 2Figure 1 shows a schematic representation of vehicle 1, which is located in lane 6. This lane 6 is assigned to a road 10. Lane 6 is delimited by lane markings 11. These lane markings 11 are corresponding road markings applied to the road surface. Using the computing unit 3, these lane markings 11 can be detected based on the environmental data provided by the environmental sensor 4.

[0031] If these lane markings 11 are detected with a predetermined probability or certainty for a predetermined debouncing time, the functionality of the lane guidance assistant 2 can be activated. For this purpose, the lane guidance assistant 2 makes corresponding steering interventions in the steering system 8, so that the vehicle 1 is guided, for example, in the center of the lane 6.

[0032] Furthermore, the computer unit is designed to detect environmental conditions and adjust the debouncing time accordingly. Specifically, the environmental conditions are to be continuously determined or measured at defined intervals, and the debouncing time adjusted as needed. This allows the system to react to changing environmental conditions and thus avoids frequent switching between an active and a standby state of the Lane Guidance Assistant 2.

[0033] The environmental conditions can describe, firstly, the current location or position of vehicle 1. The current location can be determined based on satellite-based position data and / or digital map data. Secondly, the environmental conditions can describe the weather in the vicinity 5 of vehicle 1. The weather in the vicinity 5 can be determined based on the environmental data from the environmental sensor 4 or on weather data received by the receiver 7. Thirdly, the environmental conditions can describe the current time of day or the lighting conditions in the vicinity 5. This data regarding the current time of day or lighting can also be determined by the environmental sensor 4 or on time data or similar sources. Finally, the environmental conditions can describe the road type of road 10 to which lane 6 is assigned.The debounce time can then be adjusted based on specific environmental conditions. This means, in particular, that the debounce time can be increased or decreased.

[0034] The following is an example of adjusting the debounce time depending on environmental conditions: Vehicle 1 is currently located in China. Due to higher demands on the availability of driver assistance systems in the Chinese market, the debounce time for activating the lane keeping assist system 2 in this vehicle 1 is reduced by half from a standard debounce time value. This results in faster activation of the lane keeping assist system 2 after the lane markings 11 are detected, thus increasing its availability. During the journey of vehicle 1, it begins to rain. This weather condition is detected by the lane keeping assist system 2 and consequently leads to an increase in the debounce time. For example, the debounce time can be doubled based on the detected rain. After some time, the drizzle begins and the rain continues.Due to the twilight, the debounce time is doubled again. The debounce time is then adjusted as follows: Standard value * 0.5 (countryside) * 2 (rain) * 2 (twilight). The driver then enters the motorway, which is detected by the Lane Keeping Assist 2 and results in a halving of the debounce time: Standard value * 0.5 (countryside) * 2 (rain) * 2 (twilight) * 0.5 (motorway).

[0035] Taking these factors into account results in improved availability of the steering assist or lane guidance assist 2, which adapts to the common requirements of the country-specific market and at the same time allows for dynamic adaptation to given conditions.

Claims

1. Method for operating a lane guidance assistant (2) of a vehicle (1), comprising the steps of: - receiving environment data that describe surroundings (5) of the vehicle (1), - identifying lane boundaries (11) that bound a lane (6) that the vehicle (1) is currently in, and - automatically performing steering interventions to keep the vehicle (1) in the lane (6) if the lane boundaries (11) are identified for a predetermined debounce time, characterized by - continual determination of environmental conditions, the environmental conditions describing a current location of the vehicle (1), a weather in the surroundings, a current time of day and / or a road type associated with the lane (6), and - adaptation of the debounce time on the basis of the continually determined environmental conditions.

2. Method according to Claim 1, characterized in that the current location of the vehicle (1) is taken as a basis for determining a country-specific stipulation for the debounce time, and the debounce time is adapted on the basis of the country-specific stipulation.

3. Method according to Claim 1 or 2, characterized in that the weather and / or the current time of day is / are taken as a basis for determining a reliability of the identification of the lane boundaries (11) on the basis of the environment data, and the debounce time is adapted on the basis of the reliability of the identification.

4. Method according to Claim 3, characterized in that the debounce time is increased if the reliability of the identification is lower than a predetermined average value.

5. Method according to one of the preceding claims, characterized in that the debounce time is reduced if the road type is consistent with a freeway.

6. Method according to one of the preceding claims, characterized in that the environmental conditions are determined on the basis of the environment data, satellite-based position data, digital map data and / or weather data.

7. Lane guidance assistant (2) for a vehicle (1), the lane guidance assistant (2) being configured: - to receive environment data that describe surroundings (5) of the vehicle (1), - to identify lane boundaries (11) that bound a lane (6) that the vehicle (1) is currently in, and - to perform steering interventions to keep the vehicle (1) in the lane (6) if the lane boundaries (11) are identified for a predetermined debounce time, characterized in that the lane guidance assistant (2) is further configured - to continually determine environmental conditions, the environmental conditions describing a current location of the vehicle (1), a weather in the surroundings (5), a current time of day and / or a road type associated with the lane, and - to adapt the debounce time on the basis of the continually determined environmental conditions.

8. Vehicle (1), in particular an automobile, comprising a lane guidance assistant (2) according to Claim 7.