Driving strategy for exiting or entering in automatic longitudinal guidance mode

Abstract

Method for providing driver assistance for a ramp with lane widening in automatic longitudinal guidance operation, comprising: - a provision (100) of a conventional longitudinal guidance strategy which includes speed adjustments for driving through a curve, wherein - a recognition (101) of characteristic geometric properties of the ramp to be traversed, including curve points, is provided; characterized by the fact that - the recognition (101) of the characteristic geometric properties of the ramp to be traversed includes the recognition of the roadway widening belonging to the ramp; and - if the road widening associated with the ramp has been detected, a stored acceleration factor increasing the speed is multiplied on the provided speed adjustments to set a dynamic driving behavior depending on the detected properties of the ramp (102).

Description

[0001] The invention relates to a method for setting a driving strategy, specifically for entering and exiting a parking space. According to the invention, it is possible to design the system's reaction time to more closely resemble human driving behavior, which significantly reduces the disruption to traffic behind. Furthermore, the present invention relates to a correspondingly configured system arrangement. In addition, a computer program product with control commands is proposed, which implements the method and / or operates the proposed system arrangement.

[0002] DE 10 241 455 A1 discloses a device and a method for controlling the speed of a vehicle equipped with an adaptive distance and speed controller and a traction control system, wherein the maximum target acceleration output by the adaptive distance and speed controller is limited, at least during the control operation of the traction control system, to a target acceleration value that is smaller than the maximum target acceleration output by the distance and speed controller without traction control intervention.

[0003] DE 10 2011 102 437 A1 discloses a method for operating a longitudinal driver assistance system of a motor vehicle, which in a pure following mode regulates the speed of the motor vehicle so that a distance to a preceding vehicle as the control object remains constant, and which in a free driving mode regulates to a desired speed, as well as a motor vehicle with such a driver assistance system.

[0004] DE 10 2011 102 435 A1 discloses a method for operating a longitudinal driver assistance system of a motor vehicle, wherein the speed of the motor vehicle is controlled depending on at least one control data, wherein further control data include curve data relating to at least one curve to be traversed next by the motor vehicle.

[0005] DE 10 2012 213 933 A1 discloses a method for controlling a speed control system of a motor vehicle, which basically regulates the speed to a predetermined target speed, wherein at least during a curve of the motor vehicle, the speed control system regulates the speed to a predetermined reduced circular target speed within the framework of a curve mode and / or, if the current speed is lower than the target speed or a determined circular target speed, reduces acceleration or completely prevents acceleration of the motor vehicle.The invention is characterized in that, during the cornering mode, the lateral acceleration of the vehicle or a quantity corresponding to the lateral acceleration is determined, and the cornering mode is terminated when the lateral acceleration or the quantity corresponding to the lateral acceleration has at least reached or exceeded its maximum.

[0006] A longitudinal control system that enables automated intervention in the target speed (cruise control) is known. Furthermore, a conventional cruise control system has a position control function, which translates a target speed and acceleration at a given location relative to the current position. The state of the art also includes a navigation system that can transmit upcoming map attributes in the form of segments and their properties to the longitudinal control system. In addition, this document assumes a system that can automatically regulate the speed based on events (curves, roundabouts, turns, traffic lights, etc.) from the digital map.

[0007] A conventional predictive control system for curves, turns, speed limits, or roundabouts typically has a very comfortable and early start to its intervention. This is inappropriate in an exit situation, as it could obstruct traffic behind.

[0008] It is an object of the present invention to propose an improved, in particular a configurable and safe, method for driver assistance. Specifically, so-called ramps or lane widening are to be taken into account, since these require a very specific longitudinal guidance compared to conventional assistance systems. Furthermore, it is an object of the present invention to provide a correspondingly configured system arrangement and to propose a computer program product with control commands that implement the method or at least partially operate the proposed system arrangement.

[0009] The problem is solved by a method with the features according to claim 1. Further advantageous embodiments are specified in the dependent claims.

[0010] Accordingly, a method for providing driver assistance for a ramp with road widening in automatic longitudinal guidance mode is proposed, comprising providing a conventional longitudinal guidance strategy which includes speed adjustments for driving through a curve, wherein characteristic geometric properties of the ramp to be driven through, including the road widening and curve points, are recognized; and a stored acceleration factor is multiplied on the provided speed adjustments to set a dynamic driving behavior depending on the recognized properties of the ramp.

[0011] According to the invention, it was recognized that conventional driver assistance systems are not suitable for guiding a vehicle at a safe speed through a ramp with a lane widening. While systems that support cornering are generally known, they fail to recognize that a lane widening is typically present before or after a ramp, which also usually has a curve. This lane widening requires a specific method because, often, a longer straight section is provided before entering the curve, i.e., when passing through a curve entry point—namely, a separate lane within the lane widening. If a conventional method were used, the vehicle would be slowed down as soon as it entered the lane widening, thus causing a traffic obstruction.

[0012] Furthermore, the invention recognizes that ramps are often found on highways, requiring increased concentration from the driver due to the typically higher speeds on highways. Drivers also become accustomed to these higher speeds and therefore desire to be guided dynamically through the lane widening and the ramp. The cruise control system according to the invention serves this purpose by detecting such a lane widening and the subsequent ramp, which typically includes a curve. In this respect, such a ramp differs from, for example, a conventional roundabout, resulting in unsatisfactory performance from existing driver assistance systems that are not typically designed for such ramps.

[0013] When entering a roundabout, a vehicle is excessively slowed down according to conventional methods, which is undesirable, especially after exiting a motorway. Consequently, familiar speed adjustments are reused and situation-specifically augmented with a factor that increases the dynamics of longitudinal control and thus also increases the speed.

[0014] This allows for the definition of multiple curve points, each triggering a speed adjustment. This enables the current location, i.e., the driver's position, to be detected, and the conventional speed to be slightly increased when entering a lane widening. In practice, this can also lead to an absolute reduction in speed, since the conventional driving strategy involves excessive braking. Even if the intended factor, as described in the invention, only slightly increases the intended speed, an overall deceleration can still occur. However, it is crucial that such a deceleration is relatively lower than that of conventional methods optimized for, for example, roundabouts.

[0015] As the driver approaches the ramp and navigates the curve, the different curve points can be taken into account. Each time the driver passes through such a curve point, the conventionally prescribed speed for that section of the route can be increased or adjusted. This generally results in dynamic driving behavior, which is also safer. Safety is enhanced because, unlike when entering a roundabout, human drivers actually drive faster when exiting or entering a highway, rather than simply increasing their speed as currently recommended by current technology.

[0016] An analogous argument applies to merging onto a motorway, where the driver typically traverses a ramp with a curve and then merges onto the motorway, for example, via a lane widening. Here, too, the ramp can be traversed dynamically, and a corresponding acceleration factor can be applied.

[0017] According to the invention, the disadvantage is overcome, among others, that a conventional predictive control system typically initiates longitudinal control very early and comfortably on curves, turns, speed limits, or roundabouts. This is inappropriate in an exit situation, as it could (significantly) impede following traffic and potentially even cause a rear-end collision. On ramps (entrance or exit), most drivers have a higher tolerance for higher lateral acceleration, as a dynamic driving sequence is either ending or about to begin.

[0018] According to one aspect of the present invention, instead of a multi-phase operating strategy, an application-defined delay is assumed, which is significantly steeper. The control begins either when an application-defined speed (e.g., target speed) can be reached at the level of the lane widening or when a deceleration becomes directly necessary to reach an event located beyond the exit.

[0019] In the case of lane widening, the control system thus has a two-stage process. According to one aspect of the present invention, the speed is maintained from the lane widening onwards until the conventional driving strategy is activated. 1. This factor takes into account the increased perception of dynamics and results in a significantly higher vehicle speed compared to normal cornering. 2. The system's reaction time is more similar to human driving behavior and contributes to a significantly lower disruption to rear traffic.

[0020] On exit ramps, including those from highways, there are lane widenings to allow, for example, right turns. The ramp then leads off the highway. A lane widening is the broadening of a single lane to facilitate turning, entering, or exiting.

[0021] In the context of the present invention, the term "roadway widening" refers to increasing the width of a roadway. Widening the road cross-section is necessary, for example, in the area of ​​a median strip or for the creation of turning lanes and medians. For left-turn lanes, the existing lane is shifted halfway to the right. If a right-turn lane is added, it is positioned directly to the right of the existing lane. Roadway widening is permissible both on straight stretches and in curves.

[0022] One measure, if the lane widening is long enough, is not to slow down before the curve, but to approach it at a very steep angle. Once the lane widening is reached, the curve becomes relevant. To ensure it is negotiated quickly, the curve analysis, i.e., the analysis of the curve to be negotiated, is influenced by one or more additional factors.

[0023] Drivers approaching from behind would be annoyed by a conventional strategy that causes significant delays, and this could even lead to a rear-end collision. By focusing first on the lane widening, following traffic is not obstructed. According to the invention, the curve analysis is therefore expanded to include the influence of a so-called ramp. Other factors to be considered are wet conditions on exits and entrances, as well as visibility.

[0024] In one example of an exit strategy, the driver can only adjust the driving dynamics switch. The influencing parameters then change and are set according to the invention. The vehicle's behavior is positively altered without requiring any adaptation by the driver. According to one aspect of the present invention, "applicative" means that during development, it is possible to adjust the described factors. Afterward, they are permanently set in the control unit.

[0025] According to one aspect of the present invention, the ramp is configured as a road exit or a road entrance. This has the advantage that speed adaptation can take such parameters into account and thus adjust the speed differently when exiting or entering a road. Furthermore, when exiting a road (e.g., when the vehicle leaves a highway), only moderate speeds can be maintained, while when entering a road (e.g., when the vehicle enters a highway), rapid acceleration is possible.

[0026] According to another aspect of the present invention, the ramp's properties are defined as a curve radius, an incline, or a decline. This has the advantage that a lateral acceleration can be set, which indicates how fast a curve with the specified radius may be negotiated. Sporty driving modes select a higher lateral acceleration than comfortable driving modes. An incline or decline can also be taken into account when adjusting the speed, since ramps often have an incline on a descent or a decline on an ascent. Thus, the present invention specifically addresses ramp properties, which is not provided for in the prior art.

[0027] According to a further aspect of the present invention, the curve points describe a current position, a curve entry point, one or two curve apex points, and a curve exit point. This has the advantage that the geometry of the curve, which a ramp typically provides, can be described using the curve points. A speed adjustment can be triggered by passing through the curve points. According to the invention, it can be specified that exactly one curve entry point, one or more curve apex points, and exactly one curve exit point are determined. In general, one or two curve apex points can be selected. In further driving programs, a higher number of curve apex points can also be selected. This can again be selected from the curve data, and, for example, a longer curve can also include several curve apex points.

[0028] According to a further aspect of the present invention, the characteristic geometric properties of the ramp are detected using optical sensors and / or navigation data. This has the advantage that an already installed camera can be read and / or data from the navigation device can be read. Thus, a ramp and / or a corresponding lane widening can be detected, and the method according to the invention can be carried out. Furthermore, it can be read from the navigation data that the current route actually includes driving over the ramp.

[0029] According to a further aspect of the present invention, the stored acceleration factor is selected from a plurality of acceleration factors, each of which is stored in driving profiles. This has the advantage that different driving modes are provided, and the driver can choose between levels ranging from sporty to comfortable. Furthermore, individual sections of the route to be driven between curves can be specified.

[0030] According to a further aspect of the present invention, the speed adjustments are each multiplied by separate, stored acceleration factors. This has the advantage that separate speed adjustments can be set in the individual segments, i.e., from the current location through the entry into the lane widening and through the individual curve points.

[0031] According to a further aspect of the present invention, the acceleration factor is selected depending on a provided maximum lateral acceleration value. This has the advantage that a preset driving profile is taken into account, which, for example, indicates whether sporty or comfortable driving is desired. A higher lateral acceleration is tolerated in sporty driving than in comfortable mode. The acceleration factor can take this into account.

[0032] The task is also solved by a system arrangement for providing driver assistance for a ramp with road widening in automatic longitudinal guidance mode, comprising an interface unit set up to provide a conventional longitudinal guidance strategy which includes speed adjustments for driving through a curve, wherein a detection unit is set up to recognize characteristic geometric properties of the ramp to be driven through, including the road widening and curve points; and a control unit is provided which is set up to multiply a stored acceleration factor on the provided speed adjustments to set a dynamic driving behavior depending on the recognized properties of the ramp.

[0033] The interface unit can be a wired interface that reads data from a navigation device. Alternatively, the interface can be wireless and receive data via a mobile network. The detection unit can also be connected to the navigation device and / or include a camera with image recognition and processing capabilities. The control unit can be connected to a conventional cruise control system and set the speed.

[0034] The task can also be solved by a computer program product with control commands that execute the procedure and operate the proposed arrangement when run on a computer.

[0035] According to the invention, it is particularly advantageous that the method can be used to operate the proposed devices and units or the system arrangement. Furthermore, the proposed devices and equipment are suitable for carrying out the method according to the invention. Thus, each device implements structural features that are suitable for carrying out the corresponding method. However, the structural features can also be designed as method steps. The proposed method also provides steps for implementing the function of the structural features.

[0036] Further advantages, features, and details of the invention will become apparent from the following description, in which aspects of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. Likewise, the features mentioned above and those further described here can be used individually or in any combination. The embodiments shown and described are not to be understood as exhaustive but are exemplary in nature for illustrating the invention. The detailed description serves to inform those skilled in the art; therefore, known circuits, structures, and methods are not shown or explained in detail in order to avoid complicating the understanding of the present description. The figure shows: Fig. 1: A schematic flowchart of a method for providing driver assistance according to one aspect of the present invention.

[0037] Fig. Figure 1 shows in a schematic flowchart a method for providing driver assistance for a ramp with road widening in automatic longitudinal guidance mode, comprising providing 100 a conventional longitudinal guidance strategy which includes speed adjustments for driving through a curve, wherein a recognition 101 of characteristic geometric properties of the ramp to be driven through, including the road widening and curve points, is provided; and a stored acceleration factor is multiplied 102 on the provided speed adjustments to set a dynamic driving behavior depending on the recognized properties of the ramp.

[0038] The person skilled in the art recognizes that the steps may have further sub-steps and, in particular, that the process steps may be carried out iteratively and / or in a different order.

[0039] Not shown here is a data storage device or a computer-readable medium containing a computer program product with control instructions that implement the proposed method or operate the proposed system arrangement when executed on a computer.

Claims

[1] Method for providing driver assistance for a ramp with lane widening in automatic longitudinal guidance mode, comprising: - a provision (100) of a conventional longitudinal guidance strategy which includes speed adjustments for driving through a curve, wherein - a recognition (101) of characteristic geometric properties of the ramp to be traversed, including curve points, is provided; characterized by , that - the recognition (101) of the characteristic geometric properties of the ramp to be traversed includes the recognition of the roadway widening belonging to the ramp; and - if the road widening associated with the ramp has been detected, a stored acceleration factor increasing the speed is multiplied on the provided speed adjustments to set a dynamic driving behavior depending on the detected properties of the ramp (102). [2] Method according to claim 1, characterized by that the ramp exists as a road exit or a road entrance. [3] Method according to claim 1 or 2, characterized by that the properties of the ramp are present as a curve radius, a gradient or a slope. [4] Method according to any one of the preceding claims, characterized by , that the curve points describe a current location point, a curve entry point, one or two curve apex points and a curve exit point. [5] Method according to any one of the preceding claims, characterized by, that the recognition (101) of characteristic geometric properties of the ramp is carried out using optical sensors and / or navigation data. [6] Method according to any one of the preceding claims, characterized by , that the stored acceleration factor is selected from a large number of acceleration factors, each of which is stored in driving profiles. [7] Method according to any one of the preceding claims, characterized by , that the speed adjustments are each multiplied by separate stored acceleration factors. [8] Method according to any one of the preceding claims, characterized by , that the acceleration factor is selected depending on a provided maximum lateral acceleration value. [9] System arrangement for providing driver assistance for a ramp with lane widening in automatic longitudinal guidance mode, comprising: - an interface unit set up to provide (100) a conventional longitudinal guidance strategy which includes speed adjustments for driving through a curve, characterized by , that - a detection unit is equipped to recognize (101) characteristic geometric properties of the ramp to be traversed and curve points, and is also equipped to recognize the roadway widening belonging to the ramp; and - a control unit is provided which is set up to multiply a speed-increasing stored acceleration factor on the provided speed adjustments to set a dynamic driving behavior depending on the detected characteristics of the ramp (102) if the road widening belonging to the ramp has been detected. [10] Computer program product with control commands which execute the method according to any one of claims 1 to 8 when executed on a computer.

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