DE102024202981A1 - Control of the speed of a vehicle - Google Patents

Abstract

Method for controlling the speed of a vehicle, comprising the following steps:- detecting (S1) distance information from a vehicle traveling ahead by means of a distance sensor and/or Car2X data;- automatically reducing (S2) the speed of the vehicle based on the detected distance information in such a way that a predefined safety distance from the vehicle traveling ahead is not undercut;- if a distance to the vehicle traveling ahead exceeds the predefined safety distance and current and/or imminent cornering that exceeds a predetermined cornering steering angle has been detected, maintaining (S3.1) the reduced speed while cornering;- if a distance to the vehicle traveling ahead exceeds the predefined safety distance and it has been detected that the predetermined cornering steering angle is currently and/or undercut on an imminent section of the route, increasing (S3.2) the speed to a predetermined cruising speed.

Description

FIELD OF THE INVENTION

The present invention relates to a method for controlling the speed of a vehicle.

SUMMARY OF THE INVENTION

• - ein Verfahren zur Regelung der Geschwindigkeit eines Fahrzeugs mit den folgenden Schritten: Erfassen von Abstandsinformation zu einem vorausfahrenden Fahrzeug mittels eines Abstandssensors und/oder mittels Car2XDaten; Automatisches Reduzieren der Geschwindigkeit des Fahrzeugs basierend auf der erfassten Abstandsinformation, derart, dass ein vordefinierter Sicherheitsabstand zu dem vorausfahrenden Fahrzeug nicht unterschritten wird; wenn ein Abstand zum vorausfahrenden Fahrzeug den vordefinierten Sicherheitsabstand überschreitet, und eine aktuelle und/oder unmittelbar bevorstehende Kurvenfahrt, die einen vorbestimmten Kurvenlenkwinkel übersteigt, erkannt wurde, Halten der reduzierten Geschwindigkeit während der Kurvenfahrt; wenn ein Abstand zum vorausfahrenden Fahrzeug den vordefinierten Sicherheitsabstand überschreitet, und erkannt wurde, dass der vorbestimmte Kurvenlenkwinkel aktuell und/oder auf einen unmittelbar bevorstehenden Streckenabschnitt unterschritten wird, Erhöhen der Geschwindigkeit auf eine vorbestimmte Reisegeschwindigkeit.

Accordingly, it is provided:

• - a method for controlling the speed of a vehicle with the following steps: detecting distance information from a vehicle driving ahead by means of a distance sensor and/or Car2X data; automatically reducing the speed of the vehicle based on the detected distance information in such a way that a predefined safety distance from the vehicle driving ahead is not undercut; if a distance to the vehicle driving ahead exceeds the predefined safety distance and a current and/or imminent cornering that exceeds a predetermined cornering steering angle has been detected, maintaining the reduced speed while cornering; if a distance to the vehicle driving ahead exceeds the predefined safety distance and it has been detected that the predetermined cornering steering angle is currently and/or undercut on an imminent section of the route, increasing the speed to a predetermined cruising speed.

A sensor, also known as a detector, transducer, or probe, is a technical component that can qualitatively or quantitatively measure certain physical or chemical properties or conditions, such as temperature, humidity, pressure, speed, brightness, acceleration, pH value, ionic strength, electrochemical potential, and/or the material properties of its environment. These quantities are recorded using physical or chemical effects and converted into a processable electrical signal as sensor data.

Vehicle sensors are mountable or mounted on a vehicle. Vehicle sensors include optical sensors, such as cameras, lidar, radar, TOF, and other sensor technologies, such as acoustic sensors.

A distance sensor is a sensor used to measure the distance between the driver's own vehicle (ego vehicle) and objects in its surroundings. These sensors use various technologies, such as ultrasound, radar, or lidar, to collect information about the position and distance of other vehicles, pedestrians, traffic signs, or obstacles. Accordingly, a distance sensor can comprise various sensors and combinations of these.

Car2X data is data that is exchanged, for example, between vehicles or between a vehicle and traffic infrastructure or a communications center. A vehicle ahead in a curve that can no longer be visually detected by sensors could, for example, report directly to a following vehicle via Wi-Fi, etc., that it is traveling in that same curve at the corresponding speed. It is also possible for the leading vehicle to communicate with a communications center, which in turn transmits this information to the following vehicle (e.g., via a mobile network).

An imminent route section refers to the part of the route directly ahead of the vehicle that will soon be traversed. This section can refer to various distances depending on the vehicle's speed, road conditions, and visibility. The imminent route section comprises the part of the route that is next relevant for vehicle control. This includes decisions regarding speed adjustments, steering movements, anticipating curves and intersections, or detecting obstacles and traffic signs.

Computer program products typically comprise a sequence of instructions that, when the program is loaded, cause the hardware to perform a specific procedure leading to a specific result.

A driver assistance system detects a current or upcoming curve by using sensors and algorithms that collect and interpret information about the vehicle's surroundings. Cameras mounted on the vehicle can detect road markings and use image processing technologies to analyze the curvature of the road ahead. Radar systems and lidar sensors optionally supplement this data by measuring the distances to objects around the vehicle and thus detect curves. Additionally or alternatively, GPS data and digital map information can be used to determine the vehicle's position on the road and detect upcoming road features, including curves. Some vehicles Assistance systems combine these different data sources using artificial intelligence.

The difference between a hairpin bend and a curve lies in the sharpness and shape of the road. A curve describes any type of change in direction in the road, which can occur in various radii and degrees of sharpness. Curves can range from gentle and straight to tight bends.

A hairpin bend is a more specific form of curve and refers to a very sharp change in direction, often of more than 90 degrees. Hairpin bends are often found on mountain roads or on steep inclines or declines, where they serve to adapt the road to the terrain and make the gradient manageable for vehicles. A hairpin bend can be so tight that it almost requires a reversal of direction.

Although the invention is suitable for curves of any kind, it is also conceivable to implement the method in such a way that turns are detected from a predetermined angle and a speed is maintained before and/or during a turn.

The basic idea of the invention is to ensure that a preceding vehicle is not merely undetectable, but is nevertheless present within a predetermined distance from the ego vehicle before the ego vehicle is accelerated by a cruise control system.

This avoids avoidable adverse sequences of acceleration and braking maneuvers.

In vehicles with a cruise control system, the distance to the vehicle in front is maintained. It is conceivable that a vehicle in front disappears from the detection range of the ego-vehicle sensors while cornering, even though the vehicle in front is still present within a predetermined distance. If the target speed of the ego-vehicle is higher than the speed of the vehicle in front, the ego-vehicle accelerates in such scenarios.

As soon as the vehicle in front is back within the detection range of the ego vehicle sensors, the ego vehicle brakes again.

In order to avoid such sequences of acceleration and braking maneuvers, the invention provides for recognizing corresponding scenarios associated with cornering and initially maintaining the reduced speed until the apex of a curve has been passed.

Maintaining the reduced speed while cornering contributes to driving stability, as the vehicle is driven at a speed adapted to the road conditions.

Safety is increased by taking cornering dynamics into account, as the risk of losing control of the vehicle when cornering is reduced.

Adapting the speed to cornering enables more efficient fuel use by reducing unnecessary acceleration maneuvers.

Advantageous embodiments and further developments emerge from the further subclaims and from the description with reference to the figures of the drawing.

In one embodiment, cornering is detected based on a current steering angle and/or a history of the steering angle.

By taking into account the CAN signals “steering angle” and “distance traveled” already present in modern vehicles, a curve can be detected with a high degree of probability.

The detection of cornering based on the current steering angle and/or the steering angle history enables precise and timely adjustment of the vehicle speed.

The use of steering angle data for curve detection reduces the dependence on external data sources and increases the reliability of the system

In one embodiment, cornering is detected based on GPS data of the vehicle in conjunction with map data, in particular conventional map data and/or HD map data.

This allows for the validation of detected cornering and reduces misinterpretations. Furthermore, with sufficiently accurate map data, it is possible to determine at which point comfortable acceleration can be initiated or when the apex of a curve has been reached.

It is also possible to use map data with real-time traffic information and Plan or postpone acceleration based on real-time traffic information.

In one embodiment, cornering is detected based on environmental sensor data, particularly in conjunction with navigation data. The navigation data can be embodied as map data and/or navigation instructions, such as turning right. For example, it is conceivable that a vehicle ahead is leaving a road by turning. In this case, it is advantageous to make the decision regarding an acceleration maneuver dependent on whether the host vehicle will also turn or continue straight ahead.

In one embodiment, an upcoming cornering is assigned a duration after which the speed maintenance is terminated and, in particular, the method is called again.

Assigning a duration for upcoming cornering enables adaptive speed control that adapts to the length of the curve. Furthermore, the impact of unwanted false-positive curve detections—i.e., a curve is detected even though it is not actually being entered—is reduced.

Ending the speed limit after a set period prevents excessive deceleration of the vehicle and promotes efficient driving.

Reactivating the procedure after the end of the curve ensures continuous adaptation to the traffic conditions and contributes to safety and efficiency.

In one embodiment, the speed maintenance is terminated when it is detected that the steering angle is decreasing. A decrease in the steering angle indicates with a high probability that the host vehicle has passed the apex of a curve and is currently exiting the curve. A vehicle can be safely accelerated within a predefined range when exiting the curve.

A computer program product according to a method of one embodiment of the invention executes the steps of a method according to the preceding description when the computer program product runs on a computer, in particular an in-vehicle computer. When the program in question is used on a computer, the computer program product produces an effect, namely the adjustment of the longitudinal speed of a vehicle.

TABLE OF CONTENTS OF THE DRAWINGS

• 1 ein schematisches Blockdiagramm einer Ausführungsform der Erfindung;
• 2 eine Prinzipskizze einer Ausführungsform der Erfindung.

The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the schematic figures of the drawings. In the drawings:

• 1 a schematic block diagram of an embodiment of the invention;
• 2 a schematic diagram of an embodiment of the invention.

The accompanying drawings are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the noted advantages will be apparent upon review of the drawings. Elements of the drawings are not necessarily shown to scale relative to one another.

In the figures of the drawings, identical, functionally identical and acting elements, features and components are provided with the same reference symbols, unless otherwise stated.

DESCRIPTION OF EMBODIMENTS

1 shows a schematic block diagram of a method for controlling the speed of a vehicle with the steps S1, S2, S3.1 and/or S3.2.

In step S1, a distance sensor detects distance information from a vehicle traveling ahead. In step S2, the vehicle's speed is automatically reduced based on the detected distance information in order not to fall below a predefined safety distance from the vehicle traveling ahead. If the predefined safety distance is exceeded and current and/or imminent cornering is detected that exceeds a predetermined cornering steering angle, the reduced speed is maintained during cornering in step S3.1. If the predefined safety distance is exceeded and it is detected that the predetermined cornering steering angle is currently and/or is undercut in an imminent section of the road, the speed is increased to a predetermined cruising speed in step S3.2.

2 shows a schematic diagram of a speed control system 10 with a distance sensor 1, a computing unit 2, a tel for automatically reducing the speed and a means for increasing the speed 4.

Reference symbol

S1, S2, S3.1 and S3.2

Procedural steps

1

Distance sensor

2

Computing unit

3

Means for automatically reducing speed

4

Means for increasing speed

10

Cruise control system

Claims (9)

Method for controlling the speed of a vehicle, comprising the following steps: - Detecting (S1) distance information from a vehicle traveling ahead using a distance sensor and/or Car2X data; - Automatically reducing (S2) the speed of the vehicle based on the detected distance information, such that a predefined safety distance from the vehicle traveling ahead is not undercut; - If a distance to the vehicle traveling ahead exceeds the predefined safety distance, and a current and/or imminent cornering that exceeds a predetermined cornering angle has been detected: Maintaining (S3.1) the reduced speed during cornering; - If a distance to the vehicle traveling ahead exceeds the predefined safety distance, and it has been detected that the predetermined cornering angle is currently and/or is undercut on an imminent section of the road: Increasing (S3.2) the speed to a predetermined cruising speed. Procedure according to Claim 1 , where cornering is detected based on a current steering angle and/or a history of the steering angle. Method according to one of the preceding claims, wherein cornering is detected on the basis of GPS data of the vehicle in conjunction with map data, in particular conventional map data and/or HD map data. Method according to one of the preceding claims, wherein cornering is detected on the basis of environmental detection sensor data, in particular in conjunction with navigation data. Method according to one of the preceding claims, wherein cornering is detected based on Car2X data. Method according to one of the preceding claims, wherein an impending cornering is assigned a duration after which the speed maintenance is terminated, and the method is in particular called again. Method according to one of the preceding claims, wherein the maintaining of the speed is terminated when it is detected that the steering angle is reduced. A computer program product comprising instructions that cause a hardware component of a computer to execute the method according to any one of the preceding claims when the computer program is loaded onto/from or executed by the hardware component. Speed control system (10) for carrying out the method according to one of the preceding Claims 1 - 7 , comprising at least one distance sensor (1) for detecting distance information regarding vehicles traveling ahead; a computing unit (2) for evaluating the distance information and detecting cornering; means for automatically reducing the speed (3) of the vehicle so as not to fall below the desired distance; means for increasing the speed (4) to a predetermined cruising speed.