DE102020200405A1 - Safer handover of the steering task from an automatic to a driver - Google Patents

Abstract

Method (100) for handing over control of the lateral guidance of a vehicle (1) from an at least partially automated system (2) to a driver (3) of the vehicle (1), where • in the state in which the system (2) has control over the lateral guidance, a steering torque transmitter (4) that can be operated by the driver (3) is monitored (110), and predetermined criterion (130) fulfilled, the control of the lateral guidance from the system (2) to the driver (3) is passed (140) so that the driver (3) the lateral guidance of the vehicle (1) from now on with the steering torque transmitter (4th ) is able to control, where • the specified criterion (130) based on a previous history (1a) of situations in which control was previously passed from the system (2) to the driver (3), and / or based on prior information (3a ) is set (120) via the driver (3) of the vehicle (1).

Description

The present invention relates to the transfer of control over the lateral guidance of a vehicle from an at least partially automated system to a driver of the vehicle.

State of the art

Many vehicles are already equipped with automatic distance control systems which, after activation, automatically regulate the distance to the vehicle in front depending on the speed so that both a specified maximum speed and the necessary safety distance are maintained. An automatic of this type can often be overridden or deactivated by pressing the accelerator or brake pedal.

More highly automated vehicles also take over the lateral guidance, i.e. the steering of the vehicle. Here, too, the driver may need to take back control in the event of malfunctions in the automatic system or due to traffic. In analogy to automatic distance control, it is intuitive for the driver to operate the steering wheel for this purpose.

Out ( R. Fuchs et al., "Steering functions for automated driving", Automobiltechnische Zeitschrift 06/2019, 27-31 (2019) ) a process for transferring responsibility is known which uses steering the driver by at least a certain angle against the automated system as an opportunity to seamlessly return control of the lateral guidance to the driver. This also works bidirectionally, ie the driver can also transfer control back to the automated system.

Disclosure of the invention

Developed within the scope of the invention for handing over control of the lateral guidance of a vehicle from an at least partially automated system to a driver of the vehicle. The at least partially automated system can in particular work, for example, on the scale of the degree of automation according to level 3 or 4 defined by the Society of Automotive Engineers. This means that in a large class of situations the system is ready to perform all driving functions while the driver has the opportunity to take control. The difference between level 3 and level 4 is that with level 3 the driver must be ready at all times to take control when requested by the system.

In the state in which the system has control over the lateral guidance, a steering torque transmitter, such as a steering wheel, that can be operated by the driver is monitored. In response to the fact that a steering torque entered by the driver via the steering torque transmitter fulfills at least one predetermined criterion, control of the lateral guidance is transferred from the system to the driver, so that the driver can now control the lateral guidance of the vehicle with the steering torque generator.

The predefined criterion is defined on the basis of a previous history of situations in which control was previously passed from the system to the driver, and / or on the basis of advance information about the driver of the vehicle.

It was recognized that in this way, on the one hand, it can be recognized more reliably whether the driver really wants to take control of the lateral guidance. On the other hand, a criterion for the transfer of control that is adapted to the previous history or to the driver can also make the transfer of control itself more intuitive and thus safer. If, for example, the force or the moment that the driver has to exert on the steering torque transmitter to take over control is roughly comparable to the force that the driver would have to use for the desired driving maneuver in a vehicle that is not automated in terms of lateral guidance, then the final reaction of the vehicle is likely to be more consistent with the driver's intention. In particular, the reaction no longer shoots, or at least no longer so strongly, beyond the driver's intention. The need to correct the trajectory of the vehicle immediately after taking control by counter-steering is reduced. The vehicle deviates less strongly from its actually intended lane.

• • einer Trajektorie folgt, die der Fahrer nicht möchte,
• • zu nah an Straßenbegrenzungen, wie etwa Leitplanken, fährt,
• • zu abrupt einer Spurverbreiterung bzw. Spurverengung folgt,
• • fälschlicherweise einer Abbiegespur nachfährt,
• • plötzlich weißen statt gelben Fahrbahnmarkierungen in Baustellen folgt oder
• • eine missverständliche, unvollständige oder widersprüchliche Beschilderung oder Fahrbahnmarkierung, deren Sinn sich für den Fahrer dennoch erschließt, falsch deutet.

The reason for the driver to overrule the automated system and take control is usually a sudden event. Examples of such events are that of the vehicle

• • follows a trajectory that the driver does not want,
• • drives too close to road boundaries such as crash barriers,
• • a lane widening or narrowing follows too abruptly,
• • mistakenly follows a lane,
• • suddenly follows white instead of yellow road markings in construction sites or
• • misinterprets misleading, incomplete or contradicting signage or lane markings, the meaning of which is nevertheless clear to the driver.

In such situations, the driver does not have much time to think, but will react intuitively. One possible intuitive reaction is, in particular, to undertake a steering intervention with the strength that the driver is used to in non-automated vehicles. If the criterion, on the basis of which the driver is given back control of the lateral guidance of the vehicle, is tailored based on the history of such handovers and / or on the basis of advance information about the driver, then the probability is increased that the driver's intervention has exactly the desired effect achieved.

In a particularly advantageous embodiment, the predefined criterion includes that the amount of the steering torque input by the driver exceeds a predefined threshold value. This threshold value is then set on the basis of the previous history of situations or on the basis of the prior information about the driver.

For this purpose, the steering torque transmitter can in particular comprise, for example, an operating element that can be moved by the driver, such as a steering wheel. When the driver enters the steering torque, the movement of this operating element can then be inhibited with a counterforce or a counter torque until the entered steering torque exceeds the threshold value. For example, a steering wheel can turn with the steering movements of the automated system. If the driver does not agree with the course followed by the system, he can grip the steering wheel of the system in a similar way as a driving instructor does with his learner driver who does not follow the correct course. This can also include, for example, simply holding the steering wheel and thus entering a negative steering torque that works against the steering torque actually intended by the system.

If the entered steering torque exceeds the threshold value, both the counterforce or the counter torque and the influence of the system on the lateral guidance of the vehicle can advantageously be reduced using a predetermined fade-out function. As a result, the handover of control is made fluid, and it is avoided that the vehicle executes a jerky driving maneuver at the moment of the handover. A jerky maneuver could, for example, in a situation in which the maximum coefficient of friction of the tire-road contact has already been exhausted (e.g. on an icy road), that the static friction of this contact changes into sliding friction and the vehicle is difficult to control is.

On the basis of the previous history or on the basis of the advance information, in a particularly advantageous embodiment a prognosis of the steering torque can be determined which the driver is likely to enter in order to take control of the lateral guidance. The threshold value is determined on the basis of this forecast. In addition to the aforementioned previous history and the aforementioned advance information about the driver, such a prognosis can also include, for example, an assessment of the current driving situation. For example, in a driving situation in which an accident is imminent, a stronger reaction from the driver can be expected than in a driving situation in which the vehicle merely takes a path that does not correspond to the driver's wish.

• • das Fahrzeug um mehr als einen vorgegebenen Toleranzbetrag in der durch das Lenkmoment vorgegebenen Richtung querversetzt wird, und/oder
• • der Fahrer den Lenkwinkel um mehr als einen vorgegebenen Betrag in einer dem ursprünglichen Lenkmoment entgegengesetzten Richtung korrigiert,

der Schwellwert für das Lenkmoment erhöht wird. Diese beiden Feststellungen zeigen an, dass die Korrektur des vom System vorgegebenen Lenkwinkels um den Eingriff des Fahrers insgesamt stärker ausgefallen ist als dies vom Fahrer beabsichtigt war.In a particularly advantageous embodiment, the system can learn for the future from situations in which control is passed to the driver, in that in response to that

• • the vehicle is transversely offset by more than a specified tolerance amount in the direction specified by the steering torque, and / or
• • the driver corrects the steering angle by more than a specified amount in a direction opposite to the original steering torque,

the threshold value for the steering torque is increased. These two findings indicate that the correction of the steering angle specified by the system for the intervention of the driver turned out to be greater overall than was intended by the driver.

Alternatively or in combination with this, in a further particularly advantageous embodiment, a measure for the arm force that can be applied by the driver is determined, and the threshold value is established on the basis of this measure for the arm force. This is based on the knowledge that an intuitive reaction on the part of the driver (such as "little", "medium" or "firm" countersteering) often takes place with a certain proportion of the maximum available arm strength. This means that different people will react to the same situation with roughly the same proportion of their maximum arm strength, but the absolute amounts of these forces will differ significantly from person to person.

For example, the weight and / or the volume of the driver can be determined and included in the measure for arm force. Weight sensors are already installed in many vehicles to control airbags and other restraint systems. The volume of the driver can be estimated, for example, from recordings from an interior camera, or from the settings of the driver's seat and the mirrors made by the driver himself.

Lighter or volumetrically smaller people tend to have less arm strength. For example, the threshold value for the steering torque can be lowered proportionally to the weight of the driver. The weight or other constitution of the driver can also be called up, for example after appropriate approval, from a fitness or health app on a smartphone of the driver, or the driver can be asked for corresponding information when using the vehicle for the first time, which is then entered in a Stored in memory.

In particular, in the case of a vehicle that is regularly driven by several people, for example a family, a company or a car sharing pool, a profile can be saved for each driver. Each time the vehicle is used, the driver can then be recognized by any means, for example using an individualized vehicle key or using biometric features. After the detection, the corresponding profile can be called up and the threshold value can be set accordingly.

In a further particularly advantageous embodiment, the steering torque transmitter is mechanically coupled to at least one steering axle of the vehicle. The threshold value is selected to be higher than a minimum steering torque required for following the current trajectory.

The mechanical coupling of the steering torque sensor (such as a steering wheel) to the steering axle is easier to prevent technical failure than a decoupled system in which the desired steering angle is determined by sensors and transmitted to the steering axle via an actuator ("by-wire system") to back up. Even if there is no longer any auxiliary energy available, for example for power assistance, the vehicle remains steerable, albeit with increased effort. A mechanical coupling does not only work in one direction, but the managers between the tires and the road also act on the steering column. A certain minimum steering torque is therefore required so that the vehicle can follow a tight curve even at low speeds, for example. The threshold value for handing over control of the lateral guidance to the driver should be higher than this minimum steering torque.

• • das vom Fahrer eingegebene Lenkmoment nicht mindestens über eine vorgegebene Zeitspanne aufrechterhalten wird, und/oder
• • das vom Fahrer eingegebene Lenkmoment schneller als mit einer vorgegebenen Maximalrate über den Schwellwert ansteigt, und/oder
• • in Koinzidenz mit dem eingegebenen Lenkmoment mittels eines Erschütterungssensors ein Stoß gegen den Lenkmomentgeber registriert wird, das vom Fahrer eingegebene, oberhalb des Schwellwerts liegende Lenkmoment nicht zum Anlass genommen, die Kontrolle über die Querführung vom System an den Fahrer zu übergeben. Auf diese Weise kann sichergestellt werden, dass die Kontrolle über die Querführung nur dann an den Fahrer übergeben wird, wenn dieser dies auch tatsächlich wünscht und zur Übernahme der Kontrolle auch aktuell bereit ist. Hingegen führen die genannten Ereignisse, die eher auf unabsichtliche Berührungen des Lenkrads oder anderen Lenkmomentgebers hindeuten, nicht zu einer Übergabe der Kontrolle. Eine solche Übergabe würde für den Fahrer völlig überraschend kommen, so dass er hierauf möglicherweise zu spät reagiert.

In a further particularly advantageous embodiment, in response to the fact that

• • the steering torque entered by the driver is not maintained for at least a predetermined period of time, and / or
• • the steering torque entered by the driver rises faster than the threshold value at a predetermined maximum rate, and / or
• • In coincidence with the entered steering torque a shock against the steering torque sensor is registered by means of a shock sensor, the steering torque entered by the driver, which is above the threshold value, is not used as an opportunity to hand over control of the lateral guidance from the system to the driver. In this way, it can be ensured that control of the lateral guidance is only handed over to the driver if he actually wishes it and is currently ready to take over control. On the other hand, the events mentioned, which tend to indicate unintentional contact with the steering wheel or other steering torque sensors, do not result in a handover of control. Such a handover would come as a complete surprise to the driver, so that he may react too late.

In particular, the methods can be implemented in whole or in part by a computer. The invention therefore also relates to a computer program with machine-readable instructions which, when they are executed on one or more computers, cause the computer or computers to carry out one of the described methods. In this sense, control devices for vehicles and embedded systems for technical devices, which are also able to execute machine-readable instructions, are to be regarded as computers.

The invention also relates to a machine-readable data carrier and / or to a download product with the computer program. A download product is a digital product that can be transmitted via a data network, i.e. that can be downloaded by a user of the data network and that can be offered for immediate download in an online shop, for example.

Furthermore, a computer can be equipped with the computer program, with the machine-readable data carrier or with the download product.

Further measures improving the invention are illustrated in more detail below together with the description of the preferred exemplary embodiments of the invention with reference to figures.

Embodiments

• 1 Ausführungsbeispiel des Verfahrens 100;
• 2 Beispielhafte Anwendung des Verfahrens an einem Fahrzeug 1.

It shows:

• 1 Embodiment of method 100;
• 2 Exemplary application of the method on a vehicle 1.

1 Figure 3 is a schematic flow diagram of an embodiment of the method 100 . In step 110 is based on the state in which an at least partially automated system 2 control over the lateral guidance of a vehicle 1 has, one from a driver 3 controllable steering torque sensor monitored. In response to that one from the driver 3 via the steering torque transmitter 4th entered steering torque 4a a given criterion 130 fulfilled (truth value 1 ), is in step 140 control over the lateral guidance of the vehicle 1 from the system 2 to the driver 3 to hand over. That way becomes the driver 3 enabled the lateral guidance of the vehicle from now on 1 with the steering torque transmitter 4th to control.

The criterion 130 will be detailed in step 120 set. To do this, a prehistory 1a of situations in which the control of the lateral guidance was previously granted by the system 2 to the driver 3 was handed over. As an alternative or in combination with this, advance information 3a about the driver 3 of the vehicle 1 can be used.

Inside the box 120 is exemplified as the criterion 130 for the entered steering torque 4a can be formed. According to block 121 can use the specified criterion 130 involve that from the driver 3 entered steering torque 4a a predetermined threshold value in terms of amount 4b exceeds. According to block 122 this threshold value can be based on the previous history 1a of situations, or based on the prior information 3a about the driver 3 , be determined. How this can be done in detail is exemplified inside the box 122 shown.

According to block 122a can based on the previous history 1a , or on the basis of the advance information 3a , a forecast 4a ' the steering torque that the driver ( 3 ) is expected to be entered to take control of the lateral guidance. According to block 122b becomes the threshold 4b based on this forecast 4a ' set.

According to block 124 can, for example on the basis of the advance information 3a , a measure 3b for those from the driver 3 Applicable arm force can be determined. According to block 124a can use weight in particular for this purpose 3c , and / or the volume 3d , the driver 3 can be determined and used. Based on the measure 3b for the arm strength according to block 125 the threshold 4b for the steering torque 4a set.

• • das Fahrzeug 1 um mehr als einen vorgegebenen Toleranzbetrag in der durch das Lenkmoment 4a vorgegebenen Richtung querversetzt wird (Block 123a), und/oder
• • der Fahrer 3 den Lenkwinkel um mehr als einen vorgegebenen Betrag in einer dem ursprünglichen Lenkmoment 4a entgegengesetzten Richtung korrigiert (Block 123b),

der Schwellwert 4b für das Lenkmoment 4a erhöht werden.According to block 123 may in response to that within a predetermined period of time after a handover of control from the system 2 to the driver 3

• • the vehicle 1 by more than a predetermined tolerance amount in the by the steering torque 4a specified direction is offset transversely (block 123a) , and or
• • the driver 3 the steering angle by more than a predetermined amount in one of the original steering torque 4a corrected opposite direction (block 123b) ,

the threshold 4b for the steering torque 4a increase.

If the steering torque transmitter is mechanically connected to at least one steering axle 5 of the vehicle 1 is coupled, can according to block 126 the threshold 4b higher than a minimum steering torque necessary for following the current trajectory 4c to get voted.

Inside the box 130 is shown in more detail as the criterion 130 can be checked.

According to block 131 For example, it can be checked whether this is done by the driver 3 entered steering torque 4a a predetermined threshold value in terms of amount 4b exceeds its determination within the box 120 is shown in detail.

• • das vom Fahrer 3 eingegebene Lenkmoment 4a nicht mindestens über eine vorgegebene Zeitspanne aufrechterhalten wird (Block 132a), und/oder
• • das vom Fahrer 3 eingegebene Lenkmoment 4a schneller als mit einer vorgegebenen Maximalrate über den Schwellwert ansteigt (Block 132b), und/oder
• • in Koinzidenz mit dem eingegebenen Lenkmoment 4a mittels eines Erschütterungssensors 6 ein Stoß gegen den Lenkmomentgeber 4 registriert wird (Block 132c),

das vom Fahrer 3 eingegebene, oberhalb des Schwellwerts 4b liegende Lenkmoment 4a nicht zum Anlass genommen, die Kontrolle über die Querführung vom System 2 an den Fahrer 3 zu übergeben.According to block 132 can transfer control to the driver against unintentional use of the steering torque transmitter 4th secured. To this end, in response to that

• • that of the driver 3 entered steering torque 4a is not maintained for at least a specified period of time (block 132a) , and or
• • that of the driver 3 entered steering torque 4a rises faster than the specified maximum rate above the threshold value (block 132b) , and or
• • in coincidence with the entered steering torque 4a by means of a shock sensor 6th a shock against the steering torque transmitter 4th is registered (block 132c) ,

that from the driver 3 entered, above the threshold value 4b lying steering torque 4a not taken as an opportunity to control the lateral guidance from the system 2 to the driver 3 to hand over.

As long as the entered steering torque 4a the specified threshold 4b does not exceed (truth value 0 ), can according to block 150 the movement of the control element of the steering torque transmitter that can be moved by the driver 4th with a counter-force or a counter-torque 4d be inhibited. If then later the entered steering torque 4a the threshold 4b exceeds, can according to block 160 both the counterforce and the countermoment 4d as well as the influence of the system 2 on the lateral guidance of the vehicle 1 using a specified fade-out function 160a be gradually reduced.

2 shows an exemplary application of the method 100 on a vehicle 1 , where most parts have been left out for the sake of clarity. The steering axle 5 is in the context of the at least partially automated driving function via the system 2 controlled and is at the same time with the steering wheel 4th connected as a steering torque transmitter. The steering wheel 4th So turns with when the system 2 those on the steering axle 5 coupled wheels steers. The driver 3 always has the option to use the steering wheel 4th to take in hand and with a steering torque 4a the system 2 to overrule. This overriding is done according to the procedure previously described 100 controlled. Unless the steering torque 4a the previously discussed adaptively obtained threshold value 4b does not exceed the movement of the steering wheel 4th by the counter-torque 4d inhibited. Becomes the threshold 4b exceeded, the counter-torque disappears 4b with a fade-out to zero, and the driver 3 can the steering axis 5 steer freely.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Non-patent literature cited

• R. Fuchs et al., "Steering functions for automated driving", Automobiltechnische Zeitschrift 06/2019, 27-31 (2019) [0004]

Claims (13)

Method (100) for handing over control of the lateral guidance of a vehicle (1) from an at least partially automated system (2) to a driver (3) of the vehicle (1), wherein • in the state in which the system (2) has control over the lateral guidance, a steering torque transmitter (4) that can be operated by the driver (3) is monitored (110), and • in response to the fact that a steering torque (4a) entered by the driver (3) via the steering torque transmitter (4) fulfills at least one predetermined criterion (130), the control of the lateral guidance is passed from the system (2) to the driver (3) becomes (140), so that the driver (3) is able to control the lateral guidance of the vehicle (1) from now on with the steering torque transmitter (4), whereby The specified criterion (130) based on a previous history (1a) of situations in which control was previously passed from the system (2) to the driver (3) and / or based on prior information (3a) about the driver (3 ) of the vehicle (1) is set (120). Method (100) according to Claim 1 , the predetermined criterion (130) including (121, 131) that the steering torque (4a) entered by the driver (3) exceeds a predetermined threshold value (4b) in terms of amount, and the threshold value (4b) based on the history (1a) of Situations, or on the basis of the advance information (3a) about the driver (3), is determined (122). Method (100) according to Claim 2 , with a prognosis (4a ') of the steering torque (4a) being determined (122a), which the driver (3) is likely to enter in order to take control of the lateral guidance, based on the previous history (1a) or the advance information (3a) and wherein the threshold value (4b) is established (122b) on the basis of this prognosis (4a '). Method (100) according to one of the Claims 2 to 3 , in response to the fact that within a predetermined period of time after a handover of control from the system (2) to the driver (3) • the vehicle (1) by more than a predetermined tolerance amount in the direction predetermined by the steering torque (4a) is transversely offset (123a), and / or • the driver (3) corrects the steering angle by more than a predetermined amount in a direction opposite to the original steering torque (4a) (123b), and increases the threshold value (4b) for the steering torque (4a) becomes (123). Method (100) according to one of the Claims 2 to 4th wherein a measure (3b) for the arm force that can be applied by the driver (3) is determined (124) and the threshold value (4b) is determined (125) for the arm force on the basis of this measure (3b). Method (100) according to Claim 5 , the weight (3c) and / or the volume (3d) of the driver (3) being determined and included in the measure (3b) for arm strength (124a). Method (100) according to one of the Claims 2 to 6th , the steering torque transmitter (4) being mechanically coupled to at least one steering axle (5) of the vehicle (1) and the threshold value (4b) being selected (126) to be higher than a minimum steering torque (4c) necessary for following the current trajectory. Method (100) according to one of the Claims 2 to 7th , wherein the steering torque transmitter (4) comprises an operating element movable by the driver and wherein the movement of this operating element is inhibited (150) when the steering torque (4a) is input by the driver (3) with a counter-force or a counter-torque (4d) until the input steering torque (4a) exceeds the threshold value (4b) (131). Method (100) according to Claim 8 In response to the fact that the input steering torque (4a) exceeds the threshold value (4b) (131), both the opposing force or the opposing torque (4d) and the influence of the system (2) on the lateral guidance of the vehicle (1) be gradually reduced (160) using a predetermined fade-out function (160a). Method (100) according to one of the Claims 2 to 8th , in response to the fact that • the steering torque (4a) entered by the driver (3) is not maintained (132a) for at least a predetermined period of time, and / or • the steering torque (4a) entered by the driver (3) is faster than with a predetermined maximum rate rises above the threshold value (132b), and / or • in coincidence with the entered steering torque (4a) by means of a shock sensor (6) a shock against the steering torque transmitter (4) is registered (132c), which is entered by the driver (3) , steering torque (4a) above the threshold value (4b) is not used (132) to hand over control of the lateral guidance from the system (2) to the driver (3). Computer program, containing machine-readable instructions which, when executed on one or more computers, cause the computer or computers to implement a method (100) according to one of the Claims 1 to 10 to execute. Machine-readable data carrier and / or download product with the computer program Claim 11 . Computer equipped with the computer program according to Claim 11 , and / or with the machine-readable data carrier and / or download product Claim 12 .

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