WO2024088662A1

WO2024088662A1 - Method for operating a vehicle

Info

Publication number: WO2024088662A1
Application number: PCT/EP2023/076073
Authority: WO
Inventors: Frank Niebling; Andreas Lütgert
Original assignee: Mercedes-Benz Group AG
Priority date: 2022-10-25
Filing date: 2023-09-21
Publication date: 2024-05-02
Also published as: DE102022003953B3

Abstract

The invention relates to a method for operating a vehicle (1), in which method a steering wheel of the vehicle (1) is brought into a safety position upon activation of an automated driving mode of the vehicle (1), and is brought into a steering position when a driving task is transferred from the vehicle (1) to a driver of the vehicle (1). According to the invention, - in the automated driving mode, a route (F) which is located ahead of the vehicle (1) and is subdivided into segments is analyzed in terms of the suitability of the driving task for being transferred, wherein a degree of suitability of the driving task for being transferred to the driver of the vehicle (1) is determined for each of the segments on the basis of an amount of a maximum steering angle predicted for the relevant segment and on the basis of a vehicle speed of the vehicle (1) predicted for the relevant segment, and - the degrees of suitability determined for each segment of the route (F) are displayed to the driver of the vehicle (1) on a display unit in the vehicle and/or are used to identify a point along the route (F) at which the steering wheel is intended to be automatically brought into the steering position.

Description

Procedure for operating a vehicle

The invention relates to a method for operating a vehicle, in which a steering wheel is positioned in a safety position when an automated ferry operation is activated and in a steering position when a driving task is transferred from the vehicle to a driver of the vehicle.

EP 2 915 718 A1 discloses a device and a method for continuously setting a limit for autonomous drive availability and a motor vehicle with such a device. The vehicle has autonomous driving capability and sensors for detecting vehicle environment information and vehicle dynamics sensors. The vehicle further comprises at least one positioning arrangement that provides map data with associated information; a route planning device that enables route planning, a vehicle driver monitoring arrangement that provides driver monitoring information; and an arrangement for detecting real-time information that detects traffic information and/or weather information. The limit for autonomous drive availability is calculated based on a planned route and at least one of vehicle environment information, vehicle dynamics parameters, driver monitoring information, map data, traffic information and weather information. Changes to the calculated limit for the planned route are output via a human-machine interface arranged in the vehicle.

In addition, DE 102021 002 297 B3 describes a vehicle with a steering wheel arrangement. The steering wheel arrangement comprises a control unit and a steering wheel arranged on a steering column, connected to the control unit and positionable from a steering position to a safety position. Furthermore, the Steering wheel arrangement an adjustment unit connected to the control unit for positioning the steering wheel arranged on the steering column from the steering position to the safety position. In addition, the steering wheel arrangement is designed to vibrate when positioned from the steering position to the safety position.

From DE 102014 225680 A1 a method for transferring a driving task to a driver of a vehicle is known, in which it is provided that a transfer phase is adapted in its duration to a state of attention of the driver, whereby environmental conditions can also be taken into account during the adaptation.

From DE 102018207677 A1 a method is known for switching the operation of a vehicle between different automation levels, in which a switch from a current automation level to a lower automation level occurs when a system limit of the current automation level is reached.

DE 102010 042 048 A1 describes a method for assisting a driver of a vehicle during an automated driving maneuver, whereby it is provided that vehicle control can be handed over to the driver if the driver intervenes in the steering or operates an accelerator pedal during the driving maneuver.

From DE 102013 110 852 A1 a method for the highly automated or autonomous operation of a vehicle on certain road sections is known, whereby the driver is shown a distance to the beginning of a road section on which highly automated or autonomous operation is possible.

From DE 102020 129 887 A1 a method is known for switching the operation of a vehicle between different levels of automation, wherein a vehicle interior function is changed during the switchover.

The invention is based on the object of specifying a method for operating a vehicle.

The object is achieved according to the invention by a method which has the features specified in claim 1. Advantageous embodiments of the invention are the subject of the subclaims.

A method for operating a vehicle provides that a steering wheel of the vehicle is positioned in a safety position when an automated ferry operation of the vehicle is activated and in a steering position when a driving task is handed over from the vehicle to a driver of the vehicle. According to the invention, in automated ferry operation, a route ahead of the vehicle and divided into segments is analyzed with regard to its suitability for handing over the driving task. The route is analyzed in such a way that a degree of suitability for handing over the driving task to the driver of the vehicle is determined for each of the segments based on an amount of a maximum steering angle predicted for the respective segment and a driving speed of the vehicle predicted for the respective segment. The determined degrees of suitability for each segment of the route are then displayed to the driver of the vehicle on a vehicle-side display unit and/or used to determine a point on the route at which the steering wheel should be automatically positioned in the steering position.

By applying the method, a stressful situation for the driver of the vehicle with regard to taking over the driving task can be largely avoided, since the method determines a suitable place to hand over the driving task and makes it easier to grip the steering wheel, especially a steering wheel with a square shape. The degree of suitability is particularly comparatively high when the vehicle is on a straight stretch of road and therefore a steering movement does not have to be carried out immediately when the steering wheel is positioned in the steering position and the driver takes over the driving task.

The procedure therefore takes into account that the vehicle is not, for example, in a comparatively tight curve when the driving task is handed over to the driver, since the level of difficulty for handing over when driving around a tight curve can be relatively high and more likely to cause an accident.

In particular, the determined different suitability levels for each segment of the route are displayed to the driver of the vehicle on a vehicle-mounted display unit. In one version, the different suitability levels are shown in different colors on the display unit. Using the different colors, for example red, yellow, green, the suitability levels can be visualized and the driver can use the color to assess whether it is currently critical or not critical to take over the driving task in order to move the vehicle in manual ferry mode.

In a further embodiment, it is provided that the driver of the vehicle, if he has the appropriate level of suitability and intends to take over the driving task, requests the positioning of the steering wheel in the steering position by operating an actuating element. The driver can therefore use the suitability levels displayed in color to determine a time at which the steering wheel is positioned from the safety position to the steering position, so that the driver can carry out the driving task in manual driving mode of the vehicle.

If the vehicle detects a need to hand over the driving task to the driver and the vehicle is currently cornering, a further development of the procedure checks whether the handover is possible at a later point in time on a segment of the route with a higher degree of suitability. The check determines a point in relation to a segment of the route that is currently or will be driven on in the future at which the handover of the driving task can take place essentially safely, without the vehicle endangering itself or other road users, such as when cornering tightly.

In a possible further development, if the check determines that the handover should take place at a later time, the steering wheel is automatically positioned in the steering position at a later time on the segment with a higher degree of suitability if the driving task is handed over at a later time. In this way, the driver of the vehicle can be made aware, in addition to the display, that he is taking over the driving task in relation to the vehicle and that the vehicle will continue to be moved in manual ferry mode.

In another possible embodiment of the method, a degree of suitability for transferring the driving task is indicated in color if the segment is a straight stretch and a wheel angle is 2° or less for a driving time of at least 3 seconds. This ensures to the greatest possible extent that the driver is ready to take over the driving task for this is stress-free and complication-free, without posing a potential danger to road users in the vicinity of the vehicle.

Furthermore, in one embodiment, the method provides that a curve radius of the route divided into segments and traffic information applicable to the route are continuously recorded. Based on the respective curve radius, the locations are then determined whose suitability for handing over the driving task is comparatively high and the handover can take place essentially stress-free for the driver.

In one embodiment of the method, a countdown is performed until the later point in time is reached and the driving task is handed over to the driver at this later point in time using a progress indicator shown on the display unit. The driver can see from the display that the handover is imminent and that the vehicle is then on a segment with a straight route, so that the handover can take place essentially without complications.

In particular, the traffic information is recorded continuously in order to identify critical traffic situations in which the driver of the vehicle should move it manually, for example in the event of an accident site on one of the segments of the route ahead of the vehicle, which the vehicle will reach relatively quickly.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

Fig. 1 schematically shows a route with a marked current position and a marked transfer end position,

Fig. 2 shows a schematic view of a route with a curve and a vehicle driving in the curve in autonomous ferry operation,

Fig. 3 schematically shows a route with a curve, a vehicle driving autonomously towards the curve and several progress indicators and Fig. 4 schematic time-dependent progress indicators for the upcoming handover of a driving task.

Corresponding parts are provided with the same reference numerals in all figures.

Figure 1 shows a route F with a straight course, wherein on the route F a current position P _a and a transfer end position P _e for the transfer of a driving task of a vehicle 1 driving in automated, in particular autonomous ferry operation, which is shown in more detail in Figures 2 and 3, are shown.

In autonomous ferry operation, a driving task related to the vehicle 1 is fully carried out by the vehicle 1, so that a driver of the vehicle 1 can pursue other activities, such as processing e-mails, reading, resting, etc., during the autonomous ferry operation.

The vehicle 1 has a so-called steer-by-wire steering system, since a steering wheel, which can also have a square shape, is not needed in autonomous ferry operation and is therefore positioned from a steering position to a safety position, which can provide the driver with more freedom. With the steering wheel positioned in the safety position, the driver's seat can be used in a variety of ways, for example, a driver's seat can be set to a reclining position.

Even at level 4 in relation to autonomous ferry operation, a driving situation can arise in which the driving task is handed back to the driver within a predetermined, so-called drop interval, for example of 30 seconds. Such a driving situation can occur due to failed sensors, for example due to icing, or for safety reasons, for example when driving through an impending construction site with several or missing lane markings, which can result in vehicle 1 losing its orientation. The driver's takeover of the driving task required by the vehicle can also take place when autonomous ferry operation ends, for example due to weather events, an accident, a narrowing of the lane, a fault report, etc. In such a driving situation, the vehicle 1 continues to drive from the current position P _a for a predetermined period of time, for example 30 seconds, to the final transfer position P _e in automated ferry operation, so that the driver has sufficient time from the current position P _a of the vehicle 1 to the final transfer position P _e to take over the driving task for the manual ferry operation of the vehicle 1.

The steering wheel is positioned from the safety position to the steering position regardless of the current curve position of the route F on which the vehicle 1 is driving. When the steering wheel is positioned to the steering position, it can collide with the driver's legs, especially if the steering wheel is square. In particular, such a risk of collision exists at comparatively high steering angles, since the square steering wheel is rotated to the steering position when it is positioned and protrudes as far downwards as possible.

In other words, taking over the driving task in a curve situation can be relatively stressful for the driver of vehicle 1, since the driver must, on the one hand, observe the traffic situation and, on the other hand, grasp the extending steering wheel in a position in which the driver also intuitively has a feeling for a set steering angle. This can be problematic when cornering, since the steering wheel is then presented to the driver in a position that is rotated compared to a rest position or zero position. A steering wheel angle is usually greater than a wheel angle, i.e. a steering angle, of steered vehicle wheels.

In addition, driving tests have shown that handing over the driving task to the driver of vehicle 1 in curves leads to a maximum load, i.e. to a stressful situation, in order to safely take over vehicle 1 again.

In order to make it easier for the driver to take over the driving task for carrying out manual ferry operation and to grasp the steering wheel, a procedure is described below.

The method provides that the route F ahead of the vehicle 1 is analyzed based on a steering angle to be set on the route F in relation to its suitability for handing over the driving task to the driver of the vehicle 1. This analysis is carried out, for example, up to a predetermined forecast horizon or up to a limit of a route F approved for autonomous ferry operation. In particular, the steering angle to be set is predicted based on a respective curve radius r of curves located on the route F, whereby a calculation of the steering angle is carried out on the basis of an algorithm stored for the autonomously driving vehicle 1.

The driver is shown a result of the analysis on a display unit in vehicle 1 so that the driver can request the handover of the driving task at the most suitable location.

In addition, the method provides that if the vehicle detects a need to transfer the driving task from vehicle 1 to the driver, for example due to an above-mentioned driving situation, it is checked whether, if it is a winding section of the route, the handover can take place on a more suitable section of the route and is initiated at a later time.

In particular, the route F to be analyzed is divided into segments, which can, for example, be of equal length. For each of the segments, an amount of a maximum steering wheel angle is predicted, which is to be set in the respective segment. In addition, for each segment, a driving speed is predicted at which the vehicle 1 is expected to drive in the respective segment.

Based on the predicted steering wheel angle and the predicted driving speed, a suitability degree is calculated for each of the segments, which represents a measure of how suitable the respective segment is for handing over the driving task to the driver of vehicle 1.

The driver of vehicle 1 is shown the different suitability levels of the route F ahead on a display unit on the vehicle, with the suitability levels being shown using different colors assigned to them. The driver of vehicle 1 is thus given the opportunity to select a segment with a high degree of suitability for taking over the driving task if he or she wishes to take over the driving task. If the driver wishes to hand over the driving task, he or she operates an actuating element so that the steering wheel is positioned at a suitable point from the safety position to the steering position.

According to Figure 2, the vehicle 1 is in a curve on the route F, where the driver wishes to take over the driving task. At a current Position P _a in the segment, i.e. in particular the curve, a steering wheel angle, i.e. a wheel angle, is more than 2°, so that a degree of suitability for handing over the driving task is comparatively low and, if necessary, a warning W is issued, which advises against handing over the driving task. For example, the course of the route F ahead of the vehicle 1 can be shown on the display unit, with the current position P _a or the segment on which the vehicle 1 is currently driving being shown in red.

At a position P _g determined in relation to the route F, from which a straight stretch of the route F begins, a steering angle is less than 2°, so that from this position P _g onwards the degree of suitability for handing over the driving task is high and is shown to the driver by means of a corresponding display. Here the segment can be shown in green.

Figure 3 shows a route F with a curve into which the autonomously driving vehicle 1 enters, whereby the vehicle is required to terminate the autonomous ferry operation based on recorded traffic information, for example due to weather conditions, an accident, a lane narrowing, another fault message, etc.

A current position P _a of vehicle 1 is at the beginning of the curve, so that the degree of suitability for handing over the driving task is low and a warning W is issued in vehicle 1 in this regard.

In addition, it is checked whether there is a point with a high degree of suitability for handing over the driving task before reaching an event E, which requires the termination of autonomous ferry operation, so that it can be initiated at a later point in time.

Using a progress indicator A, which shows progress until the point with the high suitability level is reached, the driver of vehicle 1 can see when the suitability level is high enough to hand over the driving task.

For example, the progress indicator A shows a low suitability level when entering the curve by means of a green bar B2 which is small compared to a yellow bar B1. In the middle of the curve, the two bars B1, B2 are essentially the same length, so that the suitability level is still relatively low and at the position P _g , where the straight stretch begins, the Progress indicator A a comparatively long green bar B2 as a high degree of suitability for handing over the driving task to the driver.

The progress indicator A therefore shows a countdown to the beginning of a segment in which the degree of suitability for handover is comparatively high.

In particular, a segment of the route F is determined as suitable for the transfer of the driving task if it has a comparatively straight route for a predetermined period of time of at least 3 seconds for the predicted driving speed and the steering angle is less than 2° or the steering wheel angle is less than 10°.

Figure 4 shows examples of the various progress indicators A with a time reference, whereby at a point in time t0 the warning W is issued and the suitability level for transferring the driving task is zero. Using the progress indicator A, only one yellow bar B1 is displayed.

Between the time t0 and a time t0,5 the suitability level is comparatively low, as shown in Figure 3 when the vehicle 1 moves towards a center of the curve. The green bar B2 is almost negligible compared to the yellow bar B1.

In the middle of the curve, at time t0,5, the two bars B1, B2 of the progress indicator A are of equal length and at the end of the curve, at time t0,9, the yellow bar B1 is small, so that the handover of the driving task is imminent.

At a time t _ü the suitability level for handing over the driving task is very high and the progress indicator A only shows the green bar B2, which extends across the progress indicator A.

In particular, before each intended handover of the driving task to the driver of vehicle 1, a so-called cross-check with road data is carried out, whereby a predictive route analysis is carried out with regard to straight and curved routes for a route profile within a handover interval. The transfer of the driving task, i.e. the positioning of the steering wheel from the safety position to the steering position, is only triggered if the route is straight and the steering angle is less than 2° for at least 3 seconds of remaining driving time. As described above, a straight route exists if the steering angle is less than 2° and the steering wheel angle is less than 10°.

The driving speed of vehicle 1 is predicted in particular for calculating the remaining travel time on a straight road segment.

Using the method described above, it is possible to reduce the risk of accidents and the stress situation for the driver of vehicle 1 by handing over the driving task to the driver in the most suitable driving situation possible. This suitable driving situation is determined based on the route of the stretch of road F ahead for vehicle 1 and a steering angle that can be set based on the route in conjunction with an expected driving speed. With regard to the expected driving speed that vehicle 1 will travel on a segment of route F, it is determined whether it is a motorway, a residential street, etc. In addition, traffic information, i.e. traffic reports for the route F ahead, are taken into account so that, for example, vehicle 1 is informed of a traffic jam on one of the segments.

For example, if vehicle 1 is driving on a highway at a relatively high speed around a curve and there is a speed limit for an adjacent straight segment, the priority is given to handing over the driving task at a later point in time, especially if vehicle 1 is on the straight segment. The driving task is handed over if it can be mapped, i.e. carried out, within a time range specified by law, especially 3 seconds.

Using the progress indicator A in accordance with the determined degree of suitability of a position of the vehicle 1 on the route F ahead of it, the driver of the vehicle 1 is given a forward-looking recommendation as to where he should best take over the driving task for carrying out the manual ferry operation.

Claims

Patent claims Method for operating a vehicle (1), in which a steering wheel of the vehicle (1) is positioned in a safety position upon activation of an automated driving operation of the vehicle (1) and in a steering position upon transfer of a driving task from the vehicle (1) to a driver of the vehicle (1), characterized in that

- that in automated ferry operation, a route (F) ahead of the vehicle (1) and divided into segments is analyzed with regard to the suitability of the transfer of the driving task, whereby

- for each of the segments, a degree of suitability for transferring the driving task to the driver of the vehicle (1) is determined based on a maximum steering angle value predicted for the respective segment and a driving speed of the vehicle (1) predicted for the respective segment, and

- that the determined suitability levels for each segment of the route (F) are displayed to the driver of the vehicle (1) on a vehicle-side display unit and/or are used to determine a point on the route (F) at which the steering wheel is to be automatically positioned in the steering position. Method according to claim 1, characterized in that the different suitability levels are displayed in different colors on the display unit. Method according to one of the preceding claims, characterized in that the driver of the vehicle (1) in the event of an intended Taking over the driving task requires the positioning of the steering wheel in the steering position by actuating an actuating element. Method according to one of the preceding claims, characterized in that if a need to hand over the driving task to the driver is recognized on the vehicle side and the vehicle (1) is currently cornering, a check is carried out to determine whether the handover is possible at a later time on a segment of the route (F) with a higher degree of suitability. Method according to claim 4, characterized in that if the driving task is handed over at the later time on the segment with a higher degree of suitability, the steering wheel is automatically positioned in the steering position at the later time. Method according to claim 4 or 5, characterized in that a countdown until the later time is reached and the driving task is handed over to the driver at this later time is visually output by means of a progress indicator (A) shown on the display unit. Method according to one of the preceding claims, characterized in that a degree of suitability suitable for transferring the driving task is indicated in color if the segment has a straight route and a wheel angle is 2° or less for a driving time of at least 3 seconds. Method according to one of the preceding claims, characterized in that a curve radius (r) of the route (F) divided into the segments and traffic information applicable to the route (F) are continuously recorded.