Method and assistance system for determining a preferred speed for a cornering manoeuvre of a vehicle negotiating a road bend

Abstract

The present invention relates to a method for determining a preferred speed (124) for a cornering manoeuvre of a vehicle (100) negotiating a road bend (108), wherein the preferred speed (124) is determined using road-condition information representing a current road condition (122), and using curve information representing at least one predetermined target speed (116) for the road bend, the target speed being independent of the road condition (122).

Description

[0001] Description

[0002] title

[0003] Method and assistance system for determining a preferred speed for a vehicle cornering through a road curve

[0004] Field of invention

[0005] The invention relates to a method for determining a preferred speed for a vehicle cornering through a road curve, a corresponding assistance system, and a corresponding computer program product.

[0006] State of the art

[0007] A vehicle may have an assistance system that warns the driver if they approach an upcoming curve at an inappropriate speed.

[0008] DE 10 2014 225 625 A1 describes a method for assisting a driver of a single-track motor vehicle to safely navigate a curve.

[0009] Disclosure of the invention

[0010] Against this background, the approach presented here introduces a method for determining a preferred speed for a vehicle cornering through a road curve, a corresponding assistance system, and a corresponding computer program product according to the independent claims. Advantageous further developments and improvements of the approach presented here will become apparent from the description and are described in the dependent claims. Advantages of the invention

[0011] A target speed for a road curve can be derived from actual driving data. This involves recording speed profiles of many different vehicles and drivers as they navigate the curve. The target speed can then be the lowest speed achieved during the curve, particularly at the apex.

[0012] From this target velocity and a distance to the apex, a target acceleration required to reach the target velocity at the apex can be determined.

[0013] This target acceleration can be compared to a predefined setpoint. If the target acceleration is greater than the setpoint, the driver can be warned before entering the curve that their current speed is too high.

[0014] This information can be provided more intensively the greater the difference is between the current target acceleration and the setpoint.

[0015] Target speeds for road curves are typically not determined taking road conditions into account, or are usually based on dry road conditions or represent an average of different road conditions.

[0016] The approach presented here takes current road conditions into account when warning the driver.

[0017] The approach presented here allows the target speed to be reduced if, for example, reduced traction is expected due to rain, snow or ice.

[0018] A method is proposed for determining a preferred speed for a vehicle cornering through a road curve, wherein the preferred speed is determined using road condition information representing a current road condition and curve information representing at least one predetermined target speed for the road curve that is independent of the road condition.

[0019] Ideas for embodiments of the present invention can be considered to be based, among other things, on the thoughts and findings described below.

[0020] A vehicle can be a single-track vehicle or a multi-track vehicle. In particular, the vehicle can be a motorcycle. Due to their smaller overall tire contact patch, motorcycles are more susceptible to reduced traction in curves than multi-track vehicles. The approach presented here is therefore particularly advantageous for motorcycles.

[0021] A preferred speed can be determined as a suitable speed for an upcoming curve in the road. This preferred speed can be adjusted to the expected static friction within the curve. The expected static friction can depend on the current road conditions. For example, the road curve might be dry, damp, wet, or icy. Maximum static friction can only be achieved on a dry road.

[0022] A target speed can be determined by the geometry or shape of the road curve. The tighter the road curve, the lower the target speed can be. Therefore, the target speed can depend on the curve radius of the road.

[0023] The preferred speed, the distance to the road curve, and the vehicle's current speed can define the deceleration required to reach the preferred speed. This required deceleration can be compared to at least one predefined threshold. If the required deceleration exceeds the threshold, information can be provided to the driver.

[0024] The target speed for the curve, independent of road conditions, can be read from the curve information and reduced by a speed reduction dependent on the road conditions to obtain the preferred speed. Alternatively, the target speed, independent of road conditions, can be scaled by a factor corresponding to the road conditions to obtain the preferred speed. The target speed can be higher than the preferred speed, as the target speed can be based on the maximum possible static friction. The road conditions can define the speed reduction, or the factor by which the target speed is reduced.

[0025] The curve information can alternatively contain a predefined speed data set for different road conditions. A target speed corresponding to the current road condition can be read from this data and used as the preferred speed. Multiple target speeds or target speed profiles can be stored in the curve information. These target speeds can be defined for different road conditions. In this case, the target speed that best suits the current road condition can be selected.

[0026] The speed data set can contain a variety of target speeds labeled for different road conditions. Different road conditions may have existed when the speed data set was created. The respective road condition may have been associated with the recorded speed. The speed data set can then be filtered by the current road condition to obtain the preferred speed.

[0027] The road condition in the vicinity of the vehicle can be detected by a sensor system and displayed in the road condition information. The vehicle itself can also detect the road condition. For example, the road condition can be detected visually via a camera system. Similarly, the road condition can be detected through interventions by the vehicle's safety systems. For instance, if the ABS activates even during service braking, reduced friction can be assumed. If the vehicle's rain sensor is triggered, a wet road can be assumed. The road condition can also be detected acoustically via the rolling noise of the vehicle's tires or the splashing noise caused by water spraying from a wet road surface.

[0028] Alternatively or additionally, road condition information can be read from a higher-level data management system. For example, an online weather service can provide information about rainfall. Similarly, infrastructure sensors and / or other road users can provide weather information. This also allows for the proactive selection of a suitable optimal speed before traction decreases.

[0029] The preferred speed can also be determined using driver information that reflects the driver's driving style. For example, with a more aggressive driving style, it can be assumed that the driver is highly focused and therefore reacts promptly to changing road conditions. In this case, the preferred speed can only be used as a fallback for a moment of inattention. With a more relaxed driving style, the driver may be more easily distracted, and a lower preferred speed can be set to provide timely warning.

[0030] The method is preferably computer-implemented and can be implemented, for example, in software or hardware, or in a hybrid form of software and hardware, for example, in an assistance system.

[0031] Furthermore, the approach presented here creates an assistance system, whereby the assistance system is trained to carry out, control or implement the steps of a variant of the procedure presented here in appropriate facilities.

[0032] The assistance system can be an electrical device with at least one processing unit for processing signals or data, at least one storage unit for storing signals or data, and at least one interface and / or a communication interface for reading or outputting data embedded in a communication protocol. The processing unit can be, for example, a signal processor, a so-called system ASIC, or a microcontroller for processing sensor signals and outputting data signals depending on the sensor signals. The storage unit can be, for example, flash memory, an EPROM, or a magnetic storage device. The interface can be configured as a sensor interface for reading sensor signals from a sensor and / or as an actuator interface for outputting data signals and / or control signals to an actuator.The communication interface can be configured to read or output data wirelessly and / or via a wired connection. The interfaces can also be software modules, such as those found on a microcontroller alongside other software modules.

[0033] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular if the program product or program is executed on a computer or device.

[0034] It should be noted that some of the possible features and advantages of the invention are described herein with reference to different embodiments. A person skilled in the art will recognize that the features of the control unit and the method can be suitably combined, adapted, or exchanged to arrive at further embodiments of the invention.

[0035] Brief description of the drawing

[0036] The following describes embodiments of the invention with reference to the accompanying drawing, whereby neither the drawing nor the description is to be interpreted as limiting the invention.

[0037] Fig. 1 shows a representation of a vehicle with an assistance system according to an embodiment example;

[0038] The figure is merely schematic and not to scale. Identical reference numerals denote identical or equivalent features. Embodiments of the invention

[0039] Fig. 1 shows a representation of a vehicle 100 with an assistance system 102 according to an embodiment example. The assistance system 102 is configured to provide a speed warning 104 to a driver 106 of the vehicle 100 if the driver 106 approaches an upcoming curve 108 at an excessive speed 110.

[0040] The assistance system 102 compares the current speed 110 of the vehicle 100 with a distance 112 to a vertex 114 of the road curve 108 and a stored target speed 116 at the vertex 114. From the distance 112, the current speed 110, and the target speed 116, a target acceleration 118 to reach the target speed 116 is calculated. The speed warning 104 is issued if the target acceleration 118 exceeds a threshold value 120.

[0041] The threshold value of 120 is variable and reflects the driving style of driver 106. If driver 106 drives rather leisurely, the threshold value of 120 is low. If, on the other hand, the driver drives actively, the threshold value of 120 can be higher.

[0042] The target speed of 116 is essentially dependent on the curve radius of the road curve 108. The tighter the curve, the lower the target speed of 116.

[0043] In one embodiment, the target speed 116 refers to an optimal road condition, i.e., maximum possible static friction in the road curve 108. In the approach presented here, the actual road condition 122 is automatically taken into account by reducing the target speed 116 according to the road condition 122 in order to obtain a preferred speed 124 for the road curve 108. For this purpose, the road condition 122 is read or detected, and a corresponding reduction is determined. The target speed 116 can be reduced absolutely by a road condition value or as a percentage by a road condition factor. In an alternative embodiment, different target speeds 116 are stored for the road curve 108 for different road conditions 122.Here, the correct target speed 116 is selected using the current road condition 122 and used as the preferred speed 124.

[0044] The preferred speed 124 is then used to determine the target acceleration 118. The preferred speed 124 is thus a target speed 116, taking into account the road condition 122.

[0045] Possible embodiments of the invention are summarized below or presented using slightly different wording.

[0046] An adjustment of target speeds for curve warning systems on wet roads is presented.

[0047] Systems for warning drivers of motorized two-wheelers when approaching a curve at an inappropriate speed are known, e.g. DE 10 2014 225 625 A1.

[0048] Different target speeds can be determined for different road conditions (wet / dry) using various methods. The approach presented here uses an automatic adjustment of the target speeds instead of a manual mode switch on the warning system.

[0049] Technical systems detect rain-soaked roads and automatically adjust the target speeds for the curve speed warning function accordingly, ensuring safe cornering with a motorized two-wheeler even on wet roads (i.e., with lower friction) if the warning system is heeded. Manual selection of road condition modes is not required.

[0050] Several methods are possible for detecting a wet road surface on a vehicle. For example, a wet road surface can be detected by measuring noise in the area of ​​the tires / fenders and comparing it to typical noise profiles. Spray water typically produces higher-frequency noise patterns. The different noise patterns can potentially be learned using AI (Knowledge Classification). Alternatively, rain sensors can be positioned in the area of ​​the tires / fenders. A wet road surface can also be detected by monitoring the traction control and ABS interventions. Online information from weather services (e.g., rain radar) and / or video sensors can also be used to monitor the environment.

[0051] If a journey on a rain-soaked road is detected in this way, the speeds stored in the curve speed warning system are adjusted accordingly. For example, all speeds can be reduced by a factor. This can be done depending on the curve radius or type. Alternatively, the system can switch to statistically determined target speeds from a corresponding subset of real journeys on rain-soaked roads.

[0052] The procedure is designed for motorized two-wheelers, as cornering speeds typically need to be adjusted more on wet roads than with a two-track vehicle.

[0053] Finally, it should be noted that terms such as "comprising," "encompassing," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a plurality. Reference numerals in the claims are not to be considered as limitations.

Claims

Claims 1. Method for determining a preferred speed (124) for a vehicle (100) driving through a road curve (108), wherein the preferred speed (124) is determined using road condition information (122) representing a current road condition and curve information (116) representing at least one predetermined target speed (116) independent of the road condition (122) for the road curve.

2. Method according to claim 1, wherein the target speed (116) for the road curve (108) independent of the road condition (122) is read from the curve information and reduced by a speed reduction dependent on the road condition (122) in order to obtain the preferred speed (124).

3. Method according to claim 1, wherein the target speed (116) for the road curve (108), which is independent of the road condition (122), is read from the curve information and scaled by a factor corresponding to the road condition (122) to determine the preferred speed. (124) to obtain.

4. Method according to claim 1, wherein the curve information contains a predetermined speed data set for different road conditions (122), wherein a target speed (116) corresponding to the current road condition (122) is read from the speed data set and used as the preferred speed (124).

5. Method according to claim 4, wherein the speed data set comprises a plurality of target speeds (116) labelled for different road conditions (122).

6. Method according to one of the preceding claims, wherein the road condition (122) in the area of ​​the vehicle (100) is detected by a sensor system of the vehicle (100) and is represented in the road condition information.

7. Method according to one of the preceding claims, wherein the road condition information is read from a higher-level data management system.

8. Method according to one of the preceding claims, wherein the preferred speed (124) is further determined using driver information representing a driving style of a driver (106) of the vehicle (100).

9. Assistance system (102), wherein the assistance system (102) is configured to execute, implement and / or control the method according to one of the preceding claims in appropriate facilities.

10. Computer program product configured to instruct a processor, when the computer program product is executed, to execute, implement and / or control the method according to any one of claims 1 to 9.

11. Machine-readable storage medium on which the computer program product according to claim 10 is stored.

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