DE102012214206A1 - Method for detecting curvature of lane course during operation of fully-automatic driver assistance system of motor vehicle, involves determining future lane curvature based on position-dependent data of vehicle detected as target object - Google Patents

Abstract

The method involves controlling a drive unit and a braking unit by a control unit during operation of a driver assistance system at a determined small current or future lane curvature (a,b1,b2,b3), such that the motor vehicle (F) keeps a predetermined distance to a front vehicle detected as target object (ZO). The actuator of a steering system is controlled by the control unit such that the motor vehicle is held in the detected same lane (FS1,FS2). The future lane curvature is determined depending on position-dependent data (B1,B2,B3) of the front vehicle detected as target object.

Description

The invention relates to a method for detecting the curvature of a lane course during a fully automatic, driver-independent vehicle guidance according to the preamble of claim 1.

At present, many driver manufacturers are already developing fully automatic driver assistance systems designed for driver-independent vehicle guidance that are designed to relieve the driver of the driving task in certain traffic situations by completely automatically assuming the driving task. An example is a so-called traffic jam assistant, which can be used in congestion situations on motorways. It is below a predetermined limit speed of z. B. 60 km / h both the longitudinal guidance (analog distance-based or active cruise control), as well as the transverse guidance for holding the vehicle within the lane automatically made. In a particular embodiment of such traffic jam assistants should even be allowed that the driver may take his hands off the steering wheel at least for a certain time.

Such fully automatic driver assistance systems designed for driver-independent vehicle guidance require high safety requirements, since in the event of a fault, high risks could arise both for the driver and for the other road users.

From the DE 10 2010 021 591 A1 A method for operating such a driver assistance system is already known, wherein by means of a plausibility monitoring module is continuously checked whether an error occurs. As an error case, different situations are defined, such. B. that the vehicle is driving too fast or reverse, that a certain minimum distance to a preceding vehicle is exceeded and / or that the vehicle leaves the lane. If such a fault is detected, at least one driving engagement serving to transfer the motor vehicle to a safe state is carried out.

Furthermore, such driver assistance systems may support the driver only within certain framework conditions, in part due to legal regulations. Thus, such a driver assistance system can make the driving task only up to a maximum allowed curvature. If the lane to be traveled has a greater than the maximum allowed curvature, the automatic vehicle guidance (for safety reasons) can not be continued. The problem here is when the excessive curvature is detected only very late, since it can then come due to the not be continued fully automatic vehicle management to risks for the driver and / or the other road users.

The object of the invention is now to specify a method for operating a motor vehicle that is improved with regard to an early detection of a future (too large) lane curvature during the operation of a fully automatic driver assistance system designed for driver-independent vehicle guidance.

This object is achieved by a method according to claim 1. Advantageous developments emerge from the dependent claims.

In principle, a method for operating a motor vehicle or for detecting the curvature of a lane course during operation of a fully automatic driver assistance system designed for driver-independent vehicle guidance is assumed in the invention. Such driver assistance systems are designed in such a way that they are in the presence of predetermined conditions - eg. When driving on a highway and at a speed that is below a predetermined limit speed - by means of one or more controllers, the actuators of an (electrically operated) steering system and / or the actuator of a drive system and / or brake system such that the vehicle is guided within the recognized own lane and taking into account a preceding vehicle or a front vehicle detected as a target object and possibly other road users or kept within the lane. The longitudinal guidance can be carried out analogously to the longitudinal guidance of a distance-related speed control (ACC). A further essential framework condition is the ascertained lane curvature. This determined current or future lane curvature must be smaller than a predefined maximum permitted lane curvature in order to guide the motor vehicle independently of the driver.

The basic idea of the invention is now to specify a possibility or method by which the course of curvature of the traffic lane can be determined very early on. Accordingly, the method according to the invention is characterized in that the future lane curvature is determined as a function of position-dependent data of the front vehicle detected as the target object.

The position-dependent data can advantageously be a relative angle of the target object to the motor vehicle, ie the future lane curvature becomes dependent determined from the determined relative angle of the target object to the motor vehicle. This relative angle can be determined, for example, from the data of a forward-looking camera system recognizing the target object.

Alternatively or additionally, the future lane curvature can also be determined by an (additional) evaluation of position data of the front vehicle detected as the target object. The position or the position data of the target object can by means of a corresponding sensor, which is mounted in the vehicle, such. B. a camera system or transmitted by car-to-car communication to the car.

Advantageously, the future lane curvature can be determined as a function of the position data of the motor vehicle and the target object at the same time, that is to say by evaluating the relative position data of the target object for the corresponding motor vehicle. Thus, if the relative position of the target object is known, it can be determined on the basis of the distance and the offset of the target object to the motor vehicle whether the future lane curvature will be greater than the predetermined maximum permitted lane curvature.

An even more accurate estimation of the future lane curvature can be made possible in an advantageous development in that the future lane curvature is determined directly as a function of the known traveled trajectory of the target object. The determination of the trajectory traveled by the target object can advantageously take place by continuous determination and possibly temporary storage of the position data and / or relative to the motor vehicle position data of the target object and at least partial evaluation of the stored position data.

In order to safeguard the future lane curvature determined by evaluating position data of the target object, further data, such as, for example, can be obtained during the determination. B. the data of a navigation system and / or determined data from recognized lane markers are evaluated.

If, by evaluating the position data of the target object and possibly further relevant data or information, it is determined that the future lane curvature will be greater than the predefined maximum permitted lane curvature, an optical, acoustic and / or haptic warning is advantageously output to the driver of the motor vehicle, which indicates to the driver that the fully automatic vehicle guidance can not be continued. Additionally or alternatively, a takeover request can be issued to the driver of the motor vehicle.

Additionally or alternatively, with a determined, larger future lane curvature than the predetermined maximum permitted lane curvature and an automatic braking intervention to decelerate the motor vehicle made to prevent reaching or exceeding the maximum permitted lane curvature, the vehicle has a relatively high speed and due the demolition of fully automatic vehicle guidance then the vehicle would continue to roll unchecked.

Advantageously, such a braking intervention is made in such situations that the vehicle comes to a standstill within a predetermined time interval or within a predetermined distance, if the driver does not take over the driving task or actively intervene in the vehicle management within the braking process itself. Ideally, such a braking intervention is made that the motor vehicle comes to a standstill within the distance that existed between the motor vehicle and the front vehicle at the time when it was recognized that the future lane curvature will be greater than the maximum allowed lane curvature.

With regard to the lateral guidance of the vehicle after determining that the future lane curvature will be greater than the maximum allowed lane curvature, various measures may be taken. In accordance with a first alternative, the steering system of the steering system can be controlled in such a way that the motor vehicle continues to be guided along a transverse guidance requirement or transverse guidance trajectory determined or requested on the basis of the fully automatic driver assistance system designed for the driver-independent vehicle guidance system. H. the vehicle is still kept within the track or lane center. Alternatively, however, in an advantageous development of the invention, the steering actuation of the steering system can be controlled in such a way that the motor vehicle is guided along a newly determined transverse guidance fallback trajectory. For example. In this case, it might make sense to stop the vehicle at the right or left edge of its own lane.

The invention will be explained in more detail with reference to the following embodiment. The single figure shows the first traffic situation to illustrate the determination of the future lane curvature. This determination can take place within a control unit or distributed over several control units provided for this purpose.

In the figure, a motorway section with two lanes FS1 and FS2 is shown, with a first motor vehicle F and a preceding vehicle ZO being in a traffic jam situation on the right lane FS1. The motor vehicle F is equipped with a fully automatic driver assistance system designed for driver-independent vehicle guidance, a so-called traffic jam assistant. Due to the active congestion assistant, both the longitudinal and the transverse guidance are carried out fully automatically in the vehicle F, in such a way that the vehicle is guided within the traffic lane FS1 at a predetermined distance from the detected target object ZO.

During the driver-independent vehicle guidance, the future lane curvature is now continuously determined by an evaluation of position data of the front vehicle detected as the target object (ZO). The figure shows this two different ways.

According to a first alternative, the future lane curvature a is determined by comparing the position data A of the motor vehicle F with the position data B3 of the target object ZO at the same time, ie by evaluating the relative position data of the target object ZO to the corresponding motor vehicle F such that (theoretically) a direct Connecting line VL between the motor vehicle F and the ZO is pulled and determines the future lane curvature a from it. As the figure shows, this type of determination is somewhat inaccurate, since this determined lane curvature would only be present if the motor vehicle F would control the current position B3 of the target object ZO by the shortest route.

In order to obtain a better or more accurate estimate of the future curvature of the driven lane, as part of an alternative approach, the future lane curvature is determined directly from the driven trajectory Tr of the target object, i. H. it is determined at predetermined points B1, B2 and B3 or continuously at each position, which has taken the target object ZO, from this data, the lane curvature present there (b1, b2 and b3). That the motor vehicle F as part of the fully automatic vehicle management is at least traversed a similar trajectory, as it has driven the target object ZO can thereby relatively accurately determines the future curvature of the motor vehicle driven lane curvature and appropriate measures (braking intervention, takeover request) already be initiated early.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010021591 A1 [0004]

Claims (12)

Method for detecting the curvature of a lane course during the operation of a fully automatic driver assistance system designed for driver-independent vehicle guidance by means of a control unit that controls a drive unit and / or brake unit such that during operation of this driver assistance system with a determined, smaller current or future lane curvature than a predetermined maximum permitted lane curvature the motor vehicle maintains a predetermined distance to a front vehicle detected as a target, and controls the actuator system of a steering system such that the motor vehicle is held within the recognized own lane, characterized in that the future lane curvature (a, b1, b2, b3) is determined as a function of position-dependent data (B1, B2, B3) of the front vehicle detected as the target object (ZO). A method according to claim 1, characterized in that the future lane curvature (a, b1, b2, b3) is determined as a function of the relative angle of the target object (ZO) to the motor vehicle (F). Method according to one of the preceding claims, characterized in that the future lane curvature (a, b1, b2, b3) by an evaluation of position data (B1, B2, B3) of the target object (ZO) detected front vehicle is determined. Method according to one of the preceding claims, characterized in that the future lane curvature (a) is determined as a function of the position data (A) of the motor vehicle and the position data (B3) of the target object (ZO) at the same time. Method according to one of the preceding claims, characterized in that the future lane curvature (b1, b2, b3) in dependence on the driven trajectory (Tr) of the target object (ZO) is determined. A method according to claim 5, characterized in that the driven trajectory (Tr) of the target object (ZO) by continuous detection and possibly temporary storage of the position data (B1, B2, B3) of the target object (ZO) and / or the motor vehicle (F ) relative position data of the target object (ZO) and at least partial evaluation of the stored position data (B1, B2, B3) is determined. Method according to one of the preceding claims, characterized in that to determine the future lane curvature (a, b1, b2, b3) further data, in particular data of a navigation system and / or data from recognized lane markings are evaluated. Method according to one of the preceding claims, characterized in that at a determined, larger future lane curvature (a, b1, b2, b3) than the predetermined maximum allowed lane curvature a warning to the driver of the motor vehicle and / or a takeover request to the driver of the motor vehicle is issued. Method according to one of the preceding claims, characterized in that in a determined, larger future lane curvature (a, b1, b2, b3) than the predetermined maximum permitted lane curvature an automatic braking intervention for braking the motor vehicle is made. A method according to claim 9, characterized in that such a braking intervention is performed, that the motor vehicle (F) comes to a standstill within a predetermined time interval or within a predetermined distance. A method according to claim 9 or 10, characterized in that such a braking intervention is carried out that the motor vehicle (F) comes to a standstill within the distance that existed between the motor vehicle (F) and the front vehicle (ZO) at the time at which in which it has been recognized that the future roadway curvature will be greater than the maximum allowed lane curvature. Method according to one of the preceding claims, characterized in that in a determined, larger future lane curvature (a, b1, b2, b3) than the predetermined maximum allowable lane curvature of the Lenkaktuatorik the steering system is controlled such that the motor vehicle (F) along a on Based on the fully automatic, designed for driver-independent vehicle management driver assistance system or requested Querführungsanforderung or transverse guidance trajectory or along a newly determined transverse guidance Fallback trajectory is performed.

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