EP4377935B1 - Method for checking a specified speed limit for vehicles on a roadway and method for assisting a driver - Google Patents

Description

The invention relates to a method for checking a predetermined speed limit for vehicles on a roadway and a method for assisting a driver of a vehicle.

From the DE 10 2019 203 543 A1 is a method for assessing the accident risk for a vehicle, whereby the accident risk is determined by comparing the vehicle's current speed with a permissible maximum speed. It is assumed that exceeding the permissible maximum speed leads to an increased accident risk.

From the US 2012/059 574 A1 A method for improving traffic flow on a section of road is known, in which a vehicle-external control unit determines an average speed of vehicles traveling on the section of road and issues a recommendation to the vehicles to increase their speed if the average speed is significantly lower than a speed limit specified for the section of road.

From the DE 10 2010 061 829 A1 A method for avoiding a lateral collision between a vehicle and another vehicle is known in which the direction of travel of the vehicle is changed in a controlled manner by individual wheel braking.

From the US 2014/195 068 A1 A traffic sign system is known which uses received parameters of a vehicle and received environmental conditions determines a speed at which the vehicle should travel and outputs the determined speed to the vehicle.

From the DE 10 2019 003 963 A1 A method for determining a driving strategy for a vehicle is known in which consumption-optimized control interventions for a drive train of the vehicle are generated based on a current vehicle position, on data stored in a digital map and on determined driving conditions of the vehicle.

The DE 10 2020 003 073.4 describes a method and a device for the automated driving of a vehicle. The method provides that, for a curve ahead of the vehicle, a visibility restriction expected due to the curve of at least one detection unit of an environmental sensor system directed in the direction of travel of the vehicle is determined. If it is determined that the visibility of the at least one detection unit falls below a predetermined threshold, the vehicle automatically changes lanes to the outside lane of the curve, provided that an outside lane is available, preferably without a right-hand lane requirement.

Furthermore, the DE 10 2015 223 176 A1 A driver assistance system for a vehicle with environmental sensors that sense the surroundings of the vehicle, and with a data processing unit that evaluates sensor data from the environmental sensors to detect obstacles in the vehicle's surroundings. Furthermore, a method for determining masking areas in the vehicle's surroundings is disclosed. The method provides that the sensor data generated by the environmental sensors is evaluated to detect obstacles in the vehicle's surroundings. Furthermore, masking areas that are masked by the detected obstacles and limit the field of view of the vehicle's optical environmental sensors are calculated depending on the detected obstacles.

The invention is based on the object of specifying a method for checking a predetermined speed limit for vehicles on a roadway and a method for assisting a driver of a vehicle.

The object is achieved according to the invention by a method for checking which has the features specified in claim 1 and by a method for supporting which has the features specified in claim 6.

Advantageous embodiments of the invention are the subject of the subclaims.

A method for checking a predefined speed limit for vehicles on a roadway provides for determining a situation-dependent, suitable driving speed for traveling on a section of the roadway by calculating a statistical average of the driving speeds of a plurality of vehicles recorded on the section. According to the invention, if the section of the roadway involves oncoming traffic and the width of the roadway is less than a predefined value, and if the suitable driving speed is less than the predefined speed limit, the predefined speed limit is assessed as inappropriate. If it is determined that the predefined speed limit is inappropriate, the speed limit stored in the digital map is replaced by the appropriate driving speed.

By applying the method, a section of road can be identified where the specified speed limit is inappropriate. If a vehicle travels along this section of road at a speed that corresponds to the specified speed limit, which means there is a relatively high potential for a critical situation, in particular a driving situation, to occur for the vehicle and possibly other road users in the immediate vicinity of the vehicle, then this section of road is identified by applying the method. In other words: By applying the method, a section of road with a relatively high risk potential can be identified because the specified speed limit corresponds to an excessive driving speed and the section of road therefore has a relatively high accident potential if a vehicle travels along the section of road at a speed that corresponds to the specified speed limit.

By averaging the appropriate driving speed for the section of road, the probability of a critical situation occurring on the road section, especially in the case of escaping vehicles, comparatively low. If vehicles travel at the appropriate speed on the section of road, safety on the section can be significantly increased.

When driving on such a section of road with oncoming traffic, especially if there is no central lane marking and the width of the road is less than a specified value, there is a potential for a critical situation if two vehicles are coming towards each other and have to avoid each other, each driving over an outside lane marking in order to avoid the oncoming vehicle.

If the digital map is corrected, for example by a navigation system, the driving speed that is inappropriate for this section of the route is not displayed at all, as it is then no longer stored.

In a further development of the method for checking a specified speed limit, the width of the roadway, in particular the lane width, the speeds of passing vehicles, and the positions of the passing vehicles, for example, in relation to lane markings, are determined to assess the traffic situation on the section of road for a large number of vehicles. Based on this information, it is determined whether the specified speed limit is inappropriate for driving on the section of road and therefore poses a potential hazard, particularly for oncoming vehicles on the section.

In another possible embodiment of the method for checking a specified speed limit, the determined width of the roadway, the driving speeds, and the positions of the passing vehicles are transmitted as information to an off-board computer unit that is data-linked to the respective vehicle. In particular, this information is transmitted to the off-board computer unit by vehicles of a vehicle fleet, for example, of a vehicle manufacturer, that are traveling on the roadway. The computer unit stores and continuously evaluates the transmitted information in order to check the speed limit specified for the roadway, i.e., for the section of road.

In addition, the method for checking a given speed limit provides that the computer unit carries out a statistical evaluation of the information transmitted to the computer unit by a large number of vehicles and that the section of road is assigned a An inappropriate speed limit is identified, on which a large number of vehicles are traveling at a speed that is below the speed limit stored on a digital map by a specified value. Based on the statistical analysis, it can be determined with relative certainty whether the specified speed limit is appropriate or inappropriate, thus identifying the potential danger of this section of road.

The computer unit determines a causal relationship between the roadway width being less than the specified value and a reduction in the speed of a large number of vehicles, which makes it possible to determine whether the specified speed limit is appropriate and whether the potential for critical situations on the road section is rather rare and has no connection with the specified speed limit.

By averaging the appropriate speed for the section of road, the probability of a critical situation occurring on that road section, especially with escaping vehicles, is comparatively low. If the vehicles on the section travel at the appropriate speed, safety on that section can be significantly increased.

If it is determined that the speed limit stored on the digital map is inappropriate and therefore poses a relatively high risk to oncoming vehicles, the digital map, in particular the stored speed limit, is replaced with the appropriate speed. If the digital map is corrected, for example, by a navigation system, the inappropriate speed for this section of the route is not displayed at all, as it is no longer stored.

Furthermore, the invention relates to a method for assisting a driver of a vehicle, wherein a suitable driving speed determined according to the method for checking a predetermined speed limit for vehicles on a roadway is output, in particular displayed, to the driver of the vehicle as a speed recommendation when driving on the roadway and/or is used as the basis for controlling an assistance system of the vehicle.

The speed recommendation indicates the appropriate speed for driving on the given section of road, serving primarily as a guide for the driver. This allows the driver to drive on the section at the appropriate speed, thus increasing their safety and the safety of oncoming vehicles, especially.

Alternatively or additionally, the determined suitable driving speed is used as a basis for controlling an assistance system, so that the suitable driving speed is binding for the assistance system and the vehicle travels the section of road at the suitable driving speed.

In particular, the appropriate driving speed is used as a speed recommendation in an assistance system for automated driving or in a

The assistance system for speed-dependent distance control of the respective vehicle when driving on the road is used as the basis. If the vehicle is driving on the section of road in automated driving mode or with activated speed-dependent distance control, the appropriate driving speed is specified as the set speed, i.e., the target speed. For example, if speed-dependent distance control is activated, a driving speed set by the driver is ignored due to the speed recommendation unless the set driving speed corresponds to or is lower than the appropriate driving speed.

Embodiments of the invention are explained in more detail below with reference to drawings.

Fig. 1

schematisch einen Streckenabschnitt einer Fahrbahn mit zwei entgegenkommenden Fahrzeugen, die mit einer für diesen Streckenabschnitt unangemessenen Fahrgeschwindigkeit entsprechend einer vorgegebenen Geschwindigkeitsbegrenzung fahren und

Fig. 2

schematisch den Streckenabschnitt der Fahrbahn mit zwei aneinander vorbeifahrenden Fahrzeugen nach einer Korrektur einer vorgegebenen Geschwindigkeitsbegrenzung.

Showing:

Fig. 1

schematically a section of a road with two oncoming vehicles traveling at an inappropriate speed for this section of road in accordance with a given speed limit and

Fig. 2

schematically the section of the road with two vehicles passing each other after a correction of a given speed limit.

Corresponding parts are provided with the same reference numerals in all figures.

Figure 1 shows a section S of a roadway F which is only delimited laterally by lane markings M and which lacks a central lane marking M. On the section S, two vehicles 1, 2 are driving towards each other, with the vehicles 1, 2 traveling on the section S at a speed which essentially corresponds to a speed limit of 70 km/h specified by a traffic sign 3.

The section S, i.e. the carriageway F, has a width b which is less than a predetermined value, so that the section S is designed as an unusually narrow carriageway F for two-way traffic, i.e. oncoming traffic.

According to the Figure 1 In the embodiment shown, an area B of the roadway F is shown with a dashed line. In this area B, vehicles 1, 2 traveling on the roadway F usually reduce their speed.

In general, it is known that there are numerous influences due to which certain sections of the road S are driven at a lower speed than that allowed by a curvature and/or a given speed limit.

The following describes a procedure by which a specified speed limit for vehicles 1, 2 on lane F is checked.

Such in the Figures 1 and 2 The carriageway F shown is particularly found as a country road, whereby due to the narrow width b of the carriageway F there is no central lane marking M to separate opposing lanes.

Oncoming vehicles 1, 2 cross a respective outer lane marking M and thus partially leave the lane F in order to pass each other. In doing so, vehicles 1, 2 significantly reduce their current speed relative to the specified speed limit of, for example, 70 km/h.

In the case of drivers unfamiliar with the area and/or comparatively young drivers of vehicles 1, 2, who essentially orient themselves according to the speed limit shown on traffic sign 3, there is a risk of underestimating a braking distance if two vehicles 1, 2 are approaching each other on such a carriageway F and have to brake in order to be able to overtake each other.

Drivers who are familiar with the area, on the other hand, usually choose a speed profile when driving on the roadway F that is adapted to the width b of the roadway F and which takes into account critical road sections S with oncoming vehicles 1, 2.

In particular, the procedure provides that the verification of the specified speed limit is carried out in such a way that the experience of the drivers who are familiar with the area is benefited, whereby an observed and learned driving behaviour with regard to the section S is offered to the vehicles 1, 2, which belong to a vehicle fleet, for example, as an indication or speed recommendation. becomes.

Based on the driving behavior in relation to a driving speed of a large number of vehicles 1, 2 on a comparatively narrow roadway F, in particular whose width b falls below a predetermined value, a criticality is derived.

For this purpose, the width b of the roadway F is determined based on signals recorded by sensors of an environmental sensor system of a vehicle 1, which width b is significantly less than a width b for two-way traffic.

In addition, the driving speeds of the passing vehicles 1, 2 and the positions of the passing vehicles 1, 2, in particular with respect to the lane markings M, are determined.

For evaluation, the determined width b of the roadway F, the determined driving speeds and the recorded positions of the vehicles 1, 2 passing each other are transmitted as information to a computer unit external to the vehicle (not shown in detail) which is data-technically linked to the vehicle 1.

Events such as, in particular, crossing the lane markings M, whereby the respective vehicle 1, 2 leaves the lane F at least partially, are an indication that particular caution is required on the section S and that the specified speed limit of, for example, 70 km/h for this section S in both directions is inappropriate.

In order to obtain a statistically meaningful sample, vehicles 1, 2 traveling on the route section S are observed by a large number of vehicles 1, 2, which in particular belong to one and the same vehicle fleet.

In particular, the determined width b of the roadway F is also transmitted as information to the computer unit in order to check for a causal relationship between the respective reduction in the driving speed of vehicles 1, 2 and the relatively unusually narrow roadway F. In the computer unit, a so-called backend, the causal relationship between the narrow roadway F, the vehicles 1, 2 leaving the roadway F in order to be able to pass each other and the associated reduction in the current driving speed on each section S is statistically determined based on a relatively large sample.

In particular, a statistical evaluation of the information transmitted to the computer unit by a plurality of vehicles 1, 2 is carried out by means of the computer unit and the section S with an inappropriate speed limit is identified, on which section a plurality of vehicles 1, 2 are traveling at a speed that is below the specified speed limit, which is also stored in a digital map of the vehicles 1, 2, by a specified value.

To establish the causal relationship, it is necessary to consider the specified speed limit and, for example, a reasonable cornering speed based on the curvature of the curve. In particular, it is determined that, on average, drivers travel the section S significantly slower than is required for a particular route, e.g., a curve, and in relation to the specified speed limit.

In particular, a suitable driving speed for traveling the route section S is determined by forming a statistical mean value of the respective driving speeds of the plurality of vehicles 1, 2 recorded on the route section.

If the sample size and a significant reduction in the speed of a large number of vehicles 1, 2 prove that the specified speed limit is inappropriate, the determined appropriate speed for driving on the section of road is stored in the digital map as a speed recommendation. The specified speed limit stored in the digital map is corrected by the determined appropriate speed.

This speed recommendation based on the appropriate driving speed is then displayed as a speed recommendation in the vehicle 1, 2 when driving on the roadway F to support the driver of a respective vehicle 1, 2 and/or is used as the basis for controlling an assistance system of the vehicle 1, 2, for example for automated driving or for speed-dependent distance control.

The driver of the respective vehicle 1, 2 experiences a situation-appropriate driving speed for driving on the section S through the determined suitable driving speed. Speed selection, especially on comparatively unusually narrow road surfaces F and can thereby increase his confidence in the respective assistance system.

Thus, when the speed of the vehicle 1, 2 is controlled based on the speed recommendation, the driver of the respective vehicle 1, 2 can drive in a driving style that mitigates the potential for critical situations when encountering an oncoming vehicle 1, 2 too quickly and swerving beyond a lane marking M, even in areas unfamiliar to him.

Claims (7)

1. Method for checking a specified speed limit for vehicles (1, 2) on a roadway (F), wherein

   - a situation-dependent appropriate driving speed for driving on a section (S) of the roadway (F) is determined by forming a statistical mean value of driving speeds of a plurality of vehicles (1, 2) recorded on the section (S),
   characterized in that,

   - if it is a section (S) of the roadway (F) with oncoming traffic and a width (b) of the roadway (F) falls below a specified value, and if the appropriate driving speed falls below the specified speed limit, the specified speed limit is assessed as inappropriate, and

   - if it is determined that the specified speed limit is inappropriate, the speed limit stored in a digital map is replaced by the appropriate driving speed.
2. Method according to claim 1,
   characterized in that, in order to assess a traffic situation on the section of road (S) of a plurality of vehicles (1, 2), the width (b) of the roadway (F), driving speeds of vehicles (1, 2) passing one another, and positions of the vehicles (1, 2) passing one another are determined.
3. Method according to claim 2,
   characterized in that the determined width (b) of the roadway (F), the driving speeds, and the positions of the vehicles (1, 2) passing one another are transmitted as information to a computer unit which is outside the vehicle and is data-coupled to the relevant vehicle (1, 2).
4. Method according to claim 3,
   characterized in that, by means of the computer unit, a statistical evaluation of the information transmitted to the computer unit by a plurality of vehicles (1, 2) is carried out and the section of road (S) having an inappropriate speed limit is identified, on which section a plurality of vehicles (1, 2) are traveling at a speed which falls, by a specified value, below the speed limit stored in a digital map.
5. Method according to claim 3 or 4,
   characterized in that, by means of the computer unit, a causal relationship is determined between the roadway (F), the width (b) of which falls below the specified value, and a reduction in the driving speeds of the plurality of vehicles (1, 2).
6. Method for assisting a driver of a vehicle (1, 2), wherein an appropriate driving speed determined in accordance with the method according to any of claims 1 to 5 is output as a speed recommendation to the driver of the vehicle (1, 2) when driving on the roadway (F) and/or is used as a basis for controlling an assistance system of the vehicle (1, 2).
7. Method according to claim 6,
   characterized in that the appropriate driving speed is used as a basis for a speed recommendation in an assistance system for automated driving or in an assistance system for speed-dependent distance control of the relevant vehicle (1, 2) when driving on the roadway (F).