Driving System with Automated Lateral Guidance Which Can be Deactivated by a Steering Intervention, and Method for Deactivating Automated Lateral Guidance

Abstract

A driving system for automated driving includes at least automated lateral guidance for a motor vehicle. The system is configured to determine whether one or more indications of a current or imminent manual steering intervention are present, which do not take place inadvertently and are intentional by a driver. Starting from a driving state with activated automated lateral guidance, the driving system deactivates the automated lateral guidance in response to the manual steering intervention. To deactivate the lateral guidance, a necessary steering torque operating counter to the activated lateral guidance is applied by the driver via the steering wheel within the scope of the manual steering intervention. When the at least one indication of the steering intervention intended by the driver is found to be present, the steering torque necessary to deactivate the lateral guidance is lower than when the indication of an intended steering intervention is not present.

Claims

1.-13. (canceled)

14. A driving system for automated driving with at least automated lateral guidance for a motor vehicle with a steering wheel comprising: an electronic control unit configured to: determine the presence of at least one indication that a current or imminent manual steering intervention does not take place inadvertently and is intentional by the driver, deactivate the automated lateral guidance as a reaction to a manual steering intervention starting from a driving state with activated automated lateral guidance, wherein a necessary steering torque which operates counter to the activated lateral guidance is to be applied by the driver within the context of the manual steering intervention to deactivate the lateral guidance, and reduce the necessary steering torque to deactivate the lateral guidance when the at least one indication for the steering intervention is present and less than the necessary steering torque to deactivate the lateral guidance when the at least one indication for an intended steering intervention is not present.

15. The driving system according to claim 14, wherein the electronic control unit is further configured to: determine a driver-side steering wheel contact, and distinguish between a first steering wheel contact mode and a second steering wheel contact mode, wherein the first steering wheel contact mode corresponds to the presence of the at least one indication for a current or imminent steering intervention which is intended by the driver the driving system, and the second steering wheel contact mode corresponds to the presence of at least one indication for an inadvertent current or imminent steering intervention.

16. The driving system according to claim 15, wherein the electronic control unit is further configured to: determine a two-handed contact of the steering wheel as the first steering wheel contact mode, wherein the two-handed contact includes a contact on the left-hand and right-hand side of the steering wheel rim.

17. The driving system according to claim 15, wherein the electronic control unit is further configured to: determine a contact of the steering wheel on the front and rear side of the steering wheel rim as the first steering wheel contact mode.

18. The driving system according to claim 14, wherein the electronic control unit is further configured to: determine that a variable corresponding to a driver-side steering intervention is greater than or equal to a threshold value, based on the determination, deactivate the automated lateral guidance, and reduce the threshold value in response to determining the presence of the at least one indication for the steering intervention intended by the driver.

19. The driving system according to claim 18, wherein the electronic control unit is further configured to: determine that a variable corresponding to a steering torque applied by the driver, which is linked to the driver-side steering intervention, is greater than or equal to a threshold torque, based on the determination, deactivate the lateral guidance, and reduce the threshold torque in response to determining the presence of the at least one indication for the steering intervention intended by the driver.

20. The driving system according to claim 18, wherein the electronic control unit is further configured to: determine a deviation variable corresponding to the driver-side steering intervention, wherein the deviation variable is characteristic of a deviation configured based on the steering intervention by the driver with respect to vehicle driving without steering intervention, determine the deviation variable is greater than or equal to a first deviation threshold value, deactivate the automated lateral guidance based on the determination, and reduce the first deviation threshold value in response to determining the presence of the at least one indication for the steering intervention intended by the driver.

21. The driving system according to claim 14, wherein the electronic control unit is further configured to: during a driving state with deactivated automated lateral guidance: determine virtual vehicle driving in the case of automated lateral guidance, determine a deviation variable which is characteristic of a deviation of the manual vehicle driving with respect to virtual vehicle driving in the case of automated lateral guidance, determine the deviation variable is less than or equal to a second deviation threshold value, and activate the automated lateral guidance again based on the determination.

22. The driving system according to claim 21, wherein the electronic control unit is further configured to: activate the automated lateral guidance again when it is determined that the deviation is less than or equal to the second deviation threshold value for a minimum time duration.

23. The driving system according to claim 14, wherein the electronic control unit is further configured to: in a driving state with deactivated automated lateral guidance: determine that there is no longer any driver-side steering wheel contact, and activate the automated lateral guidance again in a manner which is dependent thereon.

24. The driving system according to claim 23, wherein the electronic control unit is further configured to: in the driving state with deactivated automated lateral guidance: determine virtual vehicle driving in the case of automated lateral guidance, determine a deviation variable which is characteristic of a deviation of the manual vehicle driving with respect to the virtual vehicle driving in the case of automated lateral guidance, and in the case of the determination that there is no longer any driver-side steering wheel contact: activate the automated lateral guidance again if the deviation variable is less than or equal to a third deviation threshold value.

25. A method for deactivating automated lateral guidance of a driving system for automated driving for a motor vehicle with a steering wheel comprising: determining a presence of at least one indication that a current or imminent manual steering intervention does not take place inadvertently and is intended by the driver; and starting from a driving state with activated lateral guidance, deactivating the automated lateral guidance in response to the manual steering intervention, wherein a required steering torque which operates counter to the activated lateral guidance is applied by the driver to deactivate the lateral guidance during the manual steering intervention, and the steering torque necessary to deactivate the lateral guidance is lower when the at least one indication is present than when the at least one indication is not present.

26. A non-transitory computer-readable medium comprising instructions operable, when executed by one or more computing systems, to execute the method of claim 25.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG. 1a shows an example profile of the steering torque to be applied by the driver in the case of an increase of the driver-side steering intervention in the case of a conventional driver system,

[0055] FIG. 1b shows an example profile of the steering torque to be applied by the driver in the case of an increase of the driver-side steering intervention in the case of a first example embodiment of a driving system according to the present subject matter in the case of the determination of an intended steering intervention,

[0056] FIG. 1c shows an example profile of the steering torque to be applied by the driver in the case of an increase of the driver-side steering intervention in the case of a second example embodiment of a driving system according to the present subject matter in the case of the determination of an intended steering intervention,

[0057] FIG. 2 shows an example hands-on detection device,

[0058] FIG. 3a shows an example profile of a driver-side steering intervention plotted against the distance s,

[0059] FIG. 3b shows an example relationship between the threshold value M.sub.L,S for the steering torque M.sub.L and an associated tolerance range, and

[0060] FIG. 3c shows an example course of a driver-side steering intervention plotted against the distance s in the case of the activation of the automated lateral guidance.

DETAILED DESCRIPTION OF THE DRAWINGS

[0061] FIG. 1 shows the quantitative profile of the steering torque M.sub.L to be applied by the driver in the case of an increase of the driver-side steering intervention for a conventional driver system. The magnitude of the steering torque M.sub.L which is to be applied by the driver is shown on the Y-axis of the diagram, whereas the X-axis of the diagram is characteristic of the magnitude of the steering intervention and, for example, describes the deviation in the transverse direction from the trajectory which is planned by the driving system.

[0062] The curve I'm′ (shown as a straight line here for reasons of simplification) describes a trajectory which is planned by the vehicle for automated driving, on which trajectory the automated lateral guidance and, if present, also the automated longitudinal guidance are based.

[0063] For improved comprehension, FIG. 1a shows a central reservation 12 (or a driving lane marking) of the roadway 13 which is being driven on, and a right-hand roadway verge 14.

[0064] As shown in FIG. 1a, as the magnitude of the steering intervention increases to the left and the right of the planned trajectory T.sub.AF, the magnitude of the steering torque M.sub.L which is to be applied by the driver increases. Said steering torque M.sub.L of the driver operates counter to the automated lateral guidance which attempts by means of a steering counter torque to correct the deviation from the planned trajectory T.sub.AF, which deviation results from the steering intervention.

[0065] The automated lateral guidance is shut down, or deactivated, if the magnitude of the steering torque which is applied by the driver (and is determined on the system side) exceeds the threshold value M.sub.L,S (in the case of one alternative refinement: if the magnitude of the steering torque which is applied by the driver reaches the threshold value M.sub.L,S). As can be seen from FIG. 1a, the magnitude of the value of the threshold torque M.sub.L,S is relatively high. The steep curve of the steering torque M.sub.L and the high threshold torque value M.sub.L,S prevent inadvertent overriding, and keep the vehicle on the planned trajectory T.sub.AF for automated driving. It is laborious for the driver, however, to exceed the high magnitude of the threshold torque M.sub.L,S to deactivate the lateral guidance.

[0066] That region TB.sub.1 on the X-axis which is shown in FIG. 1a, in which no deactivation of the lateral guidance takes place, and which corresponds to the X-axis region between the two Y-values M.sub.L,S is called a tolerance range in the following text. If the tolerance range (here: tolerance range TB.sub.1) is departed from, the automated lateral guidance is shut down.

[0067] The example embodiment of the driving system according to the present subject matter can distinguish between a contact of the steering wheel by way of two hands and merely one hand. A contact by way of two hands is evaluated (in contrast to a contact by way of only a single hand) as an indication of the fact that the steering intervention which is already taking place or is directly imminent is intended by the driver. To this end, the driving system comprises, for example, the hands-on detection apparatus (shown diagrammatically in FIG. 2) for a steering wheel 1. Here, at least the sensor system is integrated into the steering wheel rim; the evaluation can take place inside or outside the steering wheel 1.

[0068] The hands-on detection device comprises a first part sensor 2a which is integrated into the left-hand half of the steering wheel rim, and a second part sensor 2b which is integrated into the right-hand half of the steering wheel rim. The part sensors 2a and 2b are, for example, two capacitive sensor mats.

[0069] The first part sensor 2a is connected electrically to a first part evaluation unit 3a which is set up to determine whether the driver makes contact by way of the left hand with the steering wheel in the sensor region of the part sensor 2a, for example, by way of measurement of a characteristic variable for the capacitance which is subjected to a change in the case of contact of the steering wheel region which is monitored by the respective part sensor. The second part sensor 2b is connected electrically to a second part evaluation unit 3b which is set up to determine whether the driver makes contact by way of the right hand with the steering wheel 1 in the sensor region of the part sensor 2b, for example, by way of measurement of a characteristic variable for the capacitance.

[0070] On the basis of the preferably digital evaluation signals of the two part evaluation units 3a, 3b which in each case indicate whether a contact by way of the left or right hand has been determined by means of the respective part sensor 2a, 2b, a determination can be carried out in the evaluation unit 4 as to whether [0071] merely a single hand bears against the steering wheel 1 (hand contact state 1H), [0072] both hands bear against the steering wheel 1, that is to say a contact takes place on both sides of the steering wheel rim (hand contact state 2H), or [0073] no hand bears against the steering wheel 1 (hand contact state OH).

[0074] The digital output signal 5 of the evaluation unit 4 indicates which of the hand contact states 2H, 1H, OH is present, and is evaluated by the driving system.

[0075] If a contact of the steering wheel by way of two hands (state 2H) is detected, the threshold value M.sub.L,S is reduced as a reaction thereto with respect to the value which is shown in FIG. 1a. If merely a contact by way of a single hand (state 1H) is detected, the threshold value M.sub.L,S corresponds to the high value which is shown in FIG. 1a.

[0076] The reduced threshold value M.sub.L,S is shown in FIG. 1b. Apart from the reduction of the threshold value M.sub.L,S, the profile of the steering torque M.sub.L plotted against the steering intervention in FIG. 1b remains unchanged in the X-direction, that is to say the stiffness/overriding capability of the steering system in the case of an increasing steering intervention behaves as in FIG. 1a, but the lateral guidance is already deactivated in the case of a relatively low magnitude of the value M.sub.L,S for the steering torque M.sub.L. The parameters of the regulating structure of the automated lateral guidance which influence the stiffness/overriding capability of the steering system preferably remain unchanged (without consideration of the threshold value M.sub.L,S).

[0077] If the driver therefore grips the steering wheel 1 by way of both hands (initially without the intention to override) and the counter torque to be overcome is lowered, the steering sensation with regard to the stiffness/overriding capability of the steering system is maintained. In comparison with FIG. 1a, however, the driver must apply a low steering torque (i.e., operate counter to a low counter torque), to deactivate the automated lateral guidance.

[0078] As can be seen from FIG. 1b, the tolerance range TB.sub.2 which describes the range of the steering intervention which is still tolerated without shutting down of the lateral guidance is decreased in comparison with the tolerance range TB.sub.1 from FIG. 1a.

[0079] FIG. 1c shows an alternative refinement with respect to FIG. 1b for the reduction of the threshold value M.sub.L,S in the case of contact of the steering wheel by way of two hands (state 2H). Here, the threshold value M.sub.L,S is both reduced with respect to FIG. 1a, but additionally the magnitude of the gradient of the steering torque curve is also reduced, that is to say the stiffness/overriding capability of the steering system is reduced in comparison with FIG. 1a. To this end, one or more parameters of the regulating structure of the automated lateral guidance which influence the stiffness/overriding capability of the steering system are preferably changed. Concepts for setting the stiffness/overriding capability in the case of a lateral guidance regulating structure are described, for example, in document DE 10 2014 208 785 A1. In contrast to FIG. 1b, the necessary steering intervention (for example, the necessary lateral deviation from the planned driving trajectory T.sub.AF) for shutting down the lateral guidance by way of the reduction of the magnitude of the gradient is considerably greater, but the steering torque M.sub.L which is necessary for shutting down the automated lateral guidance is somewhat lower. By way of adaptation of the stiffness of the steering system, in the case of a reduction of the value M.sub.L,S (in reaction to the determination of a two-handed steering wheel contact), a tolerance range TB.sub.20 can be obtained which corresponds substantially to the tolerance range TB.sub.1 without a reduction of the value M.sub.L,S (in the case of a single-handed steering wheel contact) in FIG. 1a.

[0080] Since the flanks of the steering torque M.sub.L rise less steeply in FIG. 1c than the profile in FIG. 1a and FIG. 1b, it is conceivable that the vehicle is no longer kept so precisely in its lane. Moreover, it is disadvantageous in the case of the profile in FIG. 1c with respect to FIG. 1b that the counter torque drops suddenly in the case of an initial single-handed steering intervention and a subsequent change from a single-handed steering wheel contact to a two-handed steering wheel contact.

[0081] FIGS. 3a and 3b show the change of the threshold value M.sub.L,S and the change of the tolerance range along a driving trajectory T.sub.AF which is planned by the vehicle for automated driving with consideration of the hand contact state which is determined by the hands-on detection device.

[0082] In FIG. 3a, the Y-axis describes a driver-side steering intervention plotted against the distance s of the driving trajectory T.sub.AF, here as a deviation Δ (s) between the driving trajectory T.sub.M(s) which is triggered by the driver and the driving trajectory T.sub.AF (s) of automated driving. In FIG. 3b, the X-axis corresponds to the driver-side steering intervention (here, as a deviation Δ with respect to the driving trajectory), whereas the Y-axis shows the profile of the steering torque M.sub.L.

[0083] Starting from a driving state with automated lateral guidance and preferably also automated longitudinal guidance (for example, in the case of highly automated driving on a highway), an inadvertent steering impulse with only one contact on the steering wheel (state 1H) takes place on the driver side from the distance point s.sub.1 of the driving trajectory T.sub.AF. The threshold value M.sub.L,S is not reduced and corresponds to the Y-values which are shown in FIG. 3b, are marked by way of arrows, and limit the tolerance range TB.sub.1.

[0084] The deviation Δ (s), brought about by way of the steering impulse, of the driving trajectory T.sub.M(s) which is triggered by the driver with respect to the driving trajectory T.sub.AF(s) of automated driving remains within the tolerance range TB.sub.1. This means that the magnitude of the high threshold value M.sub.L,S which is assigned to the tolerance range TB.sub.1 is not exceeded, with the result that the lateral guidance is not deactivated. If the tolerance range TB.sub.1 were left, the magnitude of the threshold value M.sub.L,S which is assigned to the tolerance range TB.sub.1 would also be exceeded, with the result that the automated lateral guidance would be shut down.

[0085] A two-handed contact of the steering wheel is determined (state 2H) at the distance point s.sub.2. In reaction thereto, the threshold value M.sub.L,S for overriding is reduced to the value which limits the tolerance range TB.sub.2 in FIG. 3b. Since the threshold value M.sub.L,S is lower, the tolerance range TB.sub.2 which is used is also smaller after the distance point s.sub.2 than the tolerance range TB.sub.1. Instead of the detection of a two-handed steering contact, it would also be conceivable to reduce the threshold M.sub.L,S and the tolerance range if reaching around the steering wheel (contact on the front and rear side of the steering wheel rim) is determined via a corresponding steering wheel sensor system (not shown in FIG. 2).

[0086] The contact of the steering wheel by way of both hands does not yet bring about shutting down of the automated lateral guidance. An intentional steering intervention of the driver takes place from the distance point s.sub.3. At the distance point s.sub.4, the steering intervention is so great that the deviation Δ (s) with respect to the driving trajectory T.sub.AF of automated driving leaves the tolerance range TB.sub.2, and therefore the magnitude of the steering torque M.sub.L which is applied by the driver exceeds the then valid threshold value M.sub.L,S. In reaction to the magnitude of the threshold value M.sub.L,S being exceeded, the automated lateral guidance is shut down.

[0087] Instead of monitoring the steering torque M.sub.L and deactivating the lateral guidance as a reaction to the threshold value M.sub.L,S being exceeded, it would also be conceivable to determine and to monitor the steering intervention in the form of the deviation Δ (s) with respect to the driving trajectory T.sub.AF, and to shut down the lateral guidance in reaction to the tolerance range TB.sub.2 being left.

[0088] For subsequent restarting of the lateral guidance, the steering intervention in the form of the deviation Δ (s) with respect to the (virtual) driving trajectory T.sub.AF is subsequently monitored and compared with the limits of the tolerance range. When the lateral guidance is deactivated, the tolerance range is increased to the broader tolerance range TB.sub.3. The tolerance range TB.sub.3 serves to restart the lateral guidance in the case of hands which bear against the steering wheel (a single hand or both hands). The lateral guidance is activated again if the deviation Δ (s) with respect to the (virtual) driving trajectory T.sub.AF lies in the tolerance range TB.sub.3 for a minimum time period T.sub.min,2. This does not take place in the example of FIG. 3a. It is determined at the distance point s.sub.5 that a hand no longer lies on the steering wheel (state HO). If this is the case, the tolerance range TB.sub.4 is increased considerably to activate the lateral guidance in comparison with the situation with one or two hands bearing against said steering wheel. If the deviation Δ (s) with respect to the driving trajectory T.sub.AF lies in the tolerance range TB.sub.4 (preferably for a defined minimum time period T.sub.min,1), the lateral guidance is activated and the vehicle is swung onto the planned trajectory T.sub.AF of automated driving. The minimum time period T.sub.min,1 does not have to be constant, but rather can be dependent, for example, on the driving angle with respect to the planned vehicle trajectory T.sub.AF of automated driving; as the magnitude of the driving angle with respect to the planned trajectory T.sub.AF increases, the minimum time period T.sub.min,1 preferably decreases. If the vehicle is, for example, on a collision course with a crash barrier and the driving angle with respect to the planned trajectory is great, the minimum time period T.sub.min,1 should be rather low. If the vehicle is driving rather parallel to the calculated trajectory T.sub.AF and therefore the driving angle with respect to the planned trajectory T.sub.AF is low, the minimum time period T.sub.min,1 can be greater in comparison, and the hands not bearing against the steering wheel can be tolerated for a somewhat longer time.

[0089] FIG. 3c shows the restarting of the lateral guidance in the case of steering wheel contact (state 1H or 2H). As soon as the deviation Δ (s) with respect to the driving trajectory T.sub.AF at the distance point s.sub.6 falls within the tolerance range TB.sub.3 again, a check is made as to whether the deviation Δ (s) with respect to the driving trajectory T.sub.AF remains in the tolerance range TB.sub.3 for a minimum time period T.sub.min,2. When the minimum time period T.sub.min,2 is reached, the automated lateral guidance is activated again from the distance point s.sub.7. The minimum time period T.sub.min,2 also does not necessarily have to be constant here, but rather can be dependent on the driving angle with respect to the planned vehicle trajectory T.sub.AF of automated driving, as has been described in the above text in relation to the minimum time period T.sub.min,1.

[0090] The tolerance ranges TB.sub.3 and TB.sub.4 for restarting the automated lateral guidance can be defined in a manner which is dependent on the driving situation. After a lane change on a multiple-lane road, it can be appropriate, for example, for a greater tolerance range for restarting of the lateral guidance to be defined, since it can be assumed that the motivation for the driver-side overriding of the automated lateral guidance was not poor lane discipline of the automated lateral guidance, but rather was the lane change which was intended by the driver.