The present application claims the benefit under 35 U.S.C. § 119 of German Patent Application No. DE 10 2023 211 978.1 filed on Nov. 30, 2023, which is expressly incorporated herein by reference in its entirety.
The present disclosure relates to driver assistance systems and driver assistance methods with at least partially automated driving functions. In particular, a computer-implemented method for determining a criticality of the evasive behavior of an at least partially automated vehicle is disclosed.
Various driver assistance systems for warning drivers and for steering or braking intervention or corresponding driver warning in dangerous situations are described in the related art. In the development of driver assistance systems into partially automated, automated, or highly automated driving systems, various approaches are pursued to avoid collisions or reduce the consequences of collisions. In principle, in order to avoid collisions, such driving systems can predict and/or carry out automated evasive maneuvers, which comprise mere braking, mere steering, or combined braking and steering relative to a collision object detected, for example, through sensor data. By planning the trajectory of the vehicle relative to the collision object, it can be determined whether an evasive maneuver is necessary and/or possible. Of great importance in such driving systems is the assessment of the evasive behavior with respect to safety. In particular, such driving systems must be secured against risks (i.e., validated) before they are introduced into the market. A safety assessment is also relevant to the optimal selection of an evasive maneuver with regard to minimal or at least reduced risk. Various criticality metrics are available for this purpose, which make it possible to quantitatively assess the driving behavior or evasive maneuvers. In principle, a distinction can be made between subcritical cases in which a collision can be avoided and critical cases in which a collision is unavoidable. In particular, criticality metrics should reliably assess driving situations at both slow and high velocities.
The present invention addresses the problem of more reliably providing a quantitative assessment of evasive behavior of an at least partially automated vehicle.
A first general aspect of the present invention relates to a computer-implemented method for determining a criticality of the evasive behavior of an at least partially automated vehicle, wherein the at least partially automated vehicle is moving at an instantaneous velocity. According to an example embodiment of the present invention, the method comprises calculating a plurality of evasive trajectories of the vehicle with respect to a referenced collision object by combining different longitudinal accelerations with different lateral accelerations. The method furthermore comprises determining an optimal trajectory, in which a minimum distance between the vehicle and the collision object is maximum, from the plurality of evasive trajectories. The method furthermore comprises determining a critical acceleration vector of an associated critical trajectory in which the minimum distance reaches a near-collision limit range. The method furthermore comprises determining a criticality of the optimal trajectory on the basis of the critical acceleration vector and an optimal acceleration vector associated with the optimal trajectory. In embodiments, determining the critical acceleration vector may comprise reducing the magnitude of the optimal acceleration vector to the critical acceleration vector at which the minimum distance reaches the near-collision limit range. In embodiments, the criticality of the optimal trajectory may be determined by forming the ratio of the magnitude of the critical acceleration vector to the magnitude of the optimal acceleration vector.
A second general aspect of the present invention relates to a computer system designed to perform the computer-implemented method for determining a criticality of the evasive behavior of an at least partially automated vehicle according to the first general aspect (or an embodiment thereof).
A third general aspect of the present invention relates to a computer program comprising commands which, when the computer program is executed by a computer system, cause the computer system to execute the computer-implemented method for determining a criticality of the evasive behavior of an at least partially automated vehicle according to the first general aspect (or an embodiment thereof).
A fourth general aspect of the present invention relates to a computer-readable medium or signal that stores and/or contains the computer program according to the third general aspect (or an embodiment thereof).
A fifth general aspect of the present invention relates to a method for testing and/or securing an at least partially automated driving function system. In the method, the criticality determined by the computer-implemented method according to the first general aspect (or an embodiment thereof) is used as an assessment criterion for the release of the at least partially automated driving function system.
A sixth general aspect of the present invention relates to a method for configuring an at least partially automated driving function system. In the method, the configuration of at least partially automated driving functions, in particular the configuration of rules for evasive maneuvers, is carried out at least on the basis of the criticality determined by the computer-implemented method according to the first general aspect (or an embodiment thereof).
The computer-implemented method according to the first general aspect (or an embodiment thereof) of the present invention can serve to obtain a quantitative assessment of driving behavior, in particular evasive behavior, of an at least partially automated vehicle. In particular, the computer-implemented method can be used to assess various evasive maneuvers with regard to a maximum usable vehicle capability. In other words, the proposed determination of the criticality can be used to assess what proportion of the total vehicle capability must be used to avoid a collision. This makes better comparability of the criticalities in different driving situations possible, in particular driving situations with different instantaneous velocities. In other words, the determined criticalities can be better compared over large velocity ranges than the minimum distances can. This can improve the selection and securing of evasive maneuvers with regard to a collision risk and/or with regard to reducing the consequences of a collision. Accordingly, the proposed method can improve a partially automated driving function. A further advantage of the proposed computer-implemented method is that the quantitative knowledge of the utilized proportion of the total vehicle capability allows an intensity (e.g., braking intensity and/or steering intensity or longitudinal acceleration and/or lateral acceleration) of a driving maneuver, for example an evasive maneuver, to be reduced or increased. This in turn can result in advantages with regard to user satisfaction or with regard to reducing wear and tear.
Some terms are used in the present disclosure in the following way:
A “longitudinal acceleration” can be regarded as the magnitude of acceleration in the longitudinal direction, i.e., in the lengthwise direction of the at least partially automated vehicle under consideration.
A “lateral acceleration” can be regarded as the magnitude of acceleration in the lateral direction, i.e., in the sideways direction of the at least partially automated vehicle under consideration.
An “acceleration vector a” is the resultant of longitudinal acceleration and lateral acceleration.
A “vehicle” can be any device that transports passengers and/or freight. A vehicle can be a motor vehicle (for example a passenger car or a truck), but also a rail vehicle. A vehicle can also be a motorized two-wheeler or three-wheeler. However, floating and flying devices can also be vehicles. Vehicles can be operating or assisted at least partially autonomously.
The term “at least partially automated” includes devices and/or processes that are partially automated, automated, and/or highly automated.
Firstly, the techniques of the present invention are discussed with reference to
As
Furthermore, with reference to
Further embodiments of the computer-implemented method 100 are explained below with reference to
Combining different longitudinal accelerations 12 with different lateral accelerations 14 in step 110 may thus comprise combining maximum usable braking capability with maximum usable steering capability, according to the maximum friction force model 10 shown in
As illustrated in
In embodiments, the criticality CRIToptimal of the optimal trajectory τoptimal may be determined by forming the ratio of the magnitude of the critical acceleration vector {right arrow over (a)}crit to the magnitude of the optimal acceleration vector {right arrow over (a)}optimal. This means that:
The proposed computer-implemented method is in particular advantageous in the use case of subcritical situations, i.e., in situations where a collision can be avoided. The value of CRIT may vary from 0 to 1. The lower the value of the criticality CRIT, the lower the proportion of the maximum usable vehicle capability that is at least necessary to prevent a collision. If the value of {right arrow over (a)}crit and thus the value of CRIT is equal to 0, no evasive maneuver is necessary. The higher the value of the criticality CRIT, the greater the proportion of the maximum usable vehicle capability that is at least necessary to prevent a collision.
In the case that none of the calculated evasive trajectories τi results in a minimum distance dmin>0, a collision cannot be prevented. This means that, in such a driving situation, dmin is negative even for the optimal trajectory τoptimal. In a first variant of the computer-implemented method 100, the criticality CRIT may be limited to 1 in such a case. In a second variant of the computer-implemented method 100, the criticality CRIT may also be greater than 1 in such a case. Analogously to the above-described reduction of the magnitude of the optimal acceleration vector {right arrow over (a)}optimal, the magnitude of the optimal acceleration vector {right arrow over (a)}optimal in this second variant may be increased to a critical acceleration vector {right arrow over (a)}crit for which a critical trajectory (τcrit) in which the minimum distance (dmin) again reaches the near-collision limit range is determined. Even in critical cases in which a collision is unavoidable, a risk assessment can thus be carried out depending on the maximum usable vehicle capability.
In embodiments of the computer-implemented method 100, an associated acceleration vector {right arrow over (a)}i, a critical acceleration vector {right arrow over (a)}i, crit, and a corresponding criticality CRITi may be determined for several, in particular all, of the calculated plurality of evasive trajectories τi. Furthermore, an optimized trajectory τoptimized may be determined on the basis of a comparison of the determined criticalities CRIToptimal, CRITi. The trajectory τi of which the criticality value is the lowest may be determined as the optimized trajectory τoptimized. The following may apply to the determined criticalities CRIT analogously to the above explanations:
In embodiments, the computer-implemented method 100 may comprise an action step for displaying the optimal trajectory τoptimal and/or the criticality CRIToptimal thereof. In embodiments, displaying may comprise an acoustic output, a visual output, and/or a vibratory output. In embodiments, the computer-implemented method 100 may comprise an action step for the autonomous or semi-autonomous adjustment of an evasive maneuver of the at least partially automated vehicle 1 according to the optimal trajectory τoptimal. In embodiments, the determined criticality CRIT, CRITi, CRIToptimal may be used to test and/or secure an at least partially automated driving function system 2 of the at least partially automated vehicle 1. For example, a release may be refused from a certain criticality value, for example from a value of CRIT=0.7 or greater.
In this regard,
Also disclosed is a computer system designed to perform the method 100 for determining a criticality CRIT of the evasive behavior of an at least partially automated vehicle 1 moving at an instantaneous velocity {right arrow over (v)}. The computer system can comprise at least one processor and/or at least one working memory. The computer system can furthermore comprise a (non-volatile) memory. In examples, all steps of the method 100 may be performed by the computer system. In some examples, individual steps of the method 100 may be performed by the computer system. Optionally, results of individual method steps that are not performed by the computer system may be received by the computer system. In embodiments, the computer system may be comprised in the at least partially automated driving function system 2 described above.
Also disclosed is a computer program designed to perform the method 100 for determining a criticality CRIT of the evasive behavior of an at least partially automated vehicle 1 moving at an instantaneous velocity {right arrow over (v)}. The computer program can be present, for example, in interpretable or in compiled form. For execution, it can (even in parts) be loaded into the RAM of a computer, for example as a bit or byte sequence. In embodiments, the computer program may be loaded into a memory of the at least partially automated driving function system 2 described above.
A computer-readable medium or signal that stores and/or contains the computer program or at least a portion thereof is also disclosed. The medium can comprise, for example, any one of RAM, ROM, EPROM, HDD, SDD, . . . , on/in which the signal is stored.
Number | Date | Country | Kind |
---|---|---|---|
10 2023 211 978.1 | Nov 2023 | DE | national |