Procedure for operating an assistance system

Abstract

Method for operating an assistance system for the automated driving operation of a vehicle (1), which follows a determined standard trajectory (S) longitudinally and laterally controlled, wherein an emergency trajectory (N) is continuously determined, along which the vehicle (1) is brought to a standstill longitudinally and laterally controlled after activation of an emergency operation of the vehicle (1), characterized in that that, in the event of an impending or already initiated lane change of the vehicle (1) from a starting lane (F1) to a destination lane (F2) according to the determined standard trajectory (S), a decision is made, depending on the position of the vehicle on the determined standard trajectory (S), as to whether the vehicle (1) should be brought to a standstill on the starting lane (F1) or on the destination lane (F2) when emergency operation is activated and that the vehicle (1) is then brought to a standstill on the starting lane (F1) if an emergency trajectory (N) is planned by means of which the vehicle (1) is brought to a standstill on the starting lane (F1) within a specified distance and / or within a specified time period, and if a specified comfort value of a lateral acceleration acting on the vehicle (1) and a specified penetration depth of the vehicle (1) into the destination lane (F2) are not exceeded.

Description

[0001] The invention relates to a method for operating an assistance system for automated driving of a vehicle, which follows a determined standard trajectory in longitudinal and lateral control, wherein an emergency trajectory is continuously determined, along which the vehicle is brought to a standstill in longitudinal and lateral control after activation of an emergency operation of the vehicle.

[0002] German patent application DE 10 2015 003 124 A1 discloses a method and a device for operating a vehicle in automated driving mode. During normal operation of the automated driving mode, an emergency target trajectory is continuously determined and stored. This trajectory is to be used as the basis for automated trajectory control of the vehicle after the occurrence of at least one predetermined fault event. Upon detection of the occurrence of at least one predetermined fault event, an emergency operating mode is activated. In this mode, the automated trajectory control of the vehicle is initiated and carried out according to the emergency target trajectory stored before the occurrence of the at least one predetermined fault event for a predetermined duration and / or until the vehicle comes to a standstill, provided that no driver takes over vehicle control.

[0003] Furthermore, DE 10 2017 011 808 A1 describes a method for controlling the movement of a vehicle in automated driving mode and a device for carrying out the method. The automated driving mode switches from a regular operating mode, in which the vehicle is automatically guided along a regular target trajectory to a predetermined destination position by means of a main control unit, to an emergency operating mode, in which the vehicle is automatically guided along an emergency operating target trajectory to an emergency stop position by means of a secondary control unit, when a malfunction of the main control unit is detected. In regular operating mode, the regular target trajectory, the emergency operating target trajectory, and the lane path of a lane traveled by the vehicle are continuously determined in a vehicle-fixed coordinate system of the main control unit.The determined emergency operating target trajectory and the determined lane path are fed to the auxiliary control unit and stored there. In emergency operating mode, the lane path of the vehicle's current lane is determined in a vehicle-specific coordinate system of the auxiliary control unit. In emergency operating mode, any deviation between the coordinate systems of the main control unit and the auxiliary control unit is compensated for based on the lane path stored in the auxiliary control unit and the lane path determined by the auxiliary control unit.

[0004] German patent DE 10 2012 217 002 A1 discloses a method for operating a vehicle in automated driving mode, in which a standard trajectory is determined along which the vehicle is guided in automated driving mode. During automated driving mode, a safety zone and an emergency trajectory leading to the safety zone are determined cyclically. In cases where automated driving mode can no longer be ensured, the vehicle is guided along the emergency trajectory into the safety zone, in particular by changing lanes onto the hard shoulder of a roadway.

[0005] From DE 10 2013 213 169 A1 a method for operating a vehicle in an automated driving mode is known, in which several different signal transmission paths are provided for the transmission of redundant signals.

[0006] From DE 10 2011 086 241 A1 a method for safely parking a vehicle at the side of the road is known, which is based on taking into account information queried from an external database.

[0007] The invention is based on the objective of providing a method for operating an assistance system for the automated driving operation of a vehicle.

[0008] The problem is solved according to the invention by a method which has the features specified in claim 1.

[0009] Advantageous embodiments of the invention are the subject of the dependent claims.

[0010] A method for operating an assistance system for automated driving of a vehicle provides that the vehicle follows a determined standard trajectory with longitudinal and lateral control, while an emergency trajectory is continuously determined along which the vehicle is brought to a standstill with longitudinal and lateral control after activation of an emergency mode. According to the invention, when the vehicle is about to change lanes from a starting lane to a destination lane according to the determined standard trajectory, a decision is made as to whether the vehicle should be brought to a standstill on the starting lane or on the destination lane when the emergency mode is activated. That is, a decision is made as to whether the impending lane change should be initiated or not, or whether the already initiated lane change should be continued or aborted.The decision is made depending on the current position of the vehicle on the determined standard trajectory.

[0011] An imminent lane change is assumed in particular if the determined standard trajectory within a given observation horizon of the vehicle indicates a lane change, i.e., if the lane change is planned within a given time or distance segment.

[0012] In the context of an upcoming lane change, the term "starting lane" refers to the lane from which the vehicle will initiate the change, i.e., its current lane. When a lane change has already begun, the term "starting lane" refers to the lane from which the change was initiated. The term "destination lane" refers to the lane in which the vehicle intends to complete the lane change, unless it is aborted prematurely.

[0013] The method provides a fallback solution for emergency operation of the vehicle, for example in the event of a failure of a main control unit of the vehicle, whereby the operation of the vehicle, in particular automated driving operation, is possible in such a case largely without redundant environmental sensors.

[0014] By applying this procedure, it can essentially be ensured that the vehicle, in emergency mode, is brought to a safe standstill on either the starting lane or the destination lane, according to the decision made when emergency mode was activated. This largely prevents other vehicles on both lanes from being obstructed or even both lanes from being blocked.

[0015] According to the invention, the vehicle is then brought to a standstill on the starting lane, and thus, in the event of an already initiated lane change, is guided back to the starting lane, if a trajectory can be planned as an emergency trajectory by means of which the vehicle is brought to a standstill on the starting lane within a predetermined distance and / or within a predetermined time period, and if a predetermined comfort value of a lateral acceleration acting on the vehicle is not exceeded and a predetermined penetration depth of the vehicle into the destination lane is not exceeded.

[0016] It can therefore be largely ruled out that, even if a lane change has already been initiated, the vehicle will abruptly abort this maneuver upon activation of emergency mode and be brought to a standstill or return to the starting lane if the lateral acceleration exceeds the comfort limit and the predetermined penetration depth into the target lane is exceeded. In this case, the lane change will be carried out and the vehicle will be steered into the target lane to decelerate in a comparatively comfortable and safe manner.

[0017] Another version of the procedure stipulates that the decision as to which lane the vehicle is brought to a standstill in is made taking into account the risk of collision in the starting and / or destination lane, and that the vehicle is brought to a standstill in the less hazardous lane. Thus, the vehicle is braked to a standstill in the lane where the risk of conflicts and collisions with other road users, especially other vehicles, is considered comparatively low.

[0018] After planning or initiating the lane change, the system continuously determines two emergency trajectories that bring the vehicle to a standstill within the specified distance and / or time on the starting lane or the destination lane. This ensures, to a large extent, that in activated emergency mode, it is possible to bring the vehicle to a safe standstill on both the starting and destination lanes.

[0019] When the vehicle's emergency mode is activated, the vehicle's hazard warning lights are automatically activated, depending on the country in which the vehicle is located, either when the emergency mode is activated or when the vehicle comes to a standstill.

[0020] By activating the hazard warning lights, other road users in the vicinity of the vehicle are made aware of the braking vehicle or the stationary vehicle, so that other road users are given the opportunity to avoid the vehicle in good time.

[0021] This involves determining the vehicle's current position using signals from a satellite-based positioning unit, thus enabling the identification of the country where the vehicle is currently located. Once the country is known, it can be determined when the vehicle's hazard warning lights should be activated to draw attention to the vehicle.

[0022] If the vehicle's emergency operation is activated, particularly due to a detected fault, a warning message is issued visually, audibly and / or haptically in the vehicle, so that a vehicle user and any other vehicle occupants present are made aware of the situation on the vehicle side.

[0023] To secure the vehicle once it has come to a standstill, a parking brake is activated and a corresponding gear setting is selected in a possible further training course, so that the vehicle is secured against rolling away.

[0024] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0025] This shows: Fig. 1. Schematic representation of a driving situation in automated driving mode of a vehicle according to the state of the art. Fig. 2 schematically depicts another driving situation in the automated driving mode of a vehicle according to the state of the art, Fig. 3 schematically a driving situation of a vehicle driving in automated driving mode when using a method according to the invention and Fig. 4 schematically shows another driving situation of the vehicle driving in automated driving mode when applying the method according to the invention.

[0026] Corresponding parts are marked with the same reference symbols in all figures.

[0027] The Fig. 1 and Fig. Figures 2 each show a driving situation of a vehicle 1 in automated driving mode according to the state of the art.

[0028] To execute automated driving operations, vehicle 1 has an assistance system which, when activated, fully performs a driving task.

[0029] In automated driving mode, a standard trajectory S is determined, in particular by means of the assistance system, which is specified to vehicle 1 and which vehicle 1 follows longitudinally and laterally controlled.

[0030] While vehicle 1 follows the standard trajectory S, an emergency trajectory N is determined, along which vehicle 1 is brought to a standstill, in particular a safe standstill, after activation of an emergency mode, for example due to a failure of a main control unit, using longitudinal and lateral control. This emergency mode is activated in particular when a safe continuation of automated driving cannot be guaranteed.

[0031] Fig. Figure 1 shows a driving situation in the automated driving mode of vehicle 1, in which a lane change of vehicle 1 from a starting lane F1 to a destination lane F2 is planned, as shown by the planned standard trajectory S.

[0032] The emergency trajectory N corresponds to the standard trajectory S in its spatial path, so that vehicle 1, in activated emergency mode, is brought to a standstill as a redundant driving function of vehicle 1 when performing the lane change. Vehicle 1 is braked in such a way that it is located in both the starting lane F1 and the destination lane F2. This may obstruct other road users, as vehicle 1, when stationary, also blocks both the starting lane F1 and the destination lane F2.

[0033] In a Fig. In the driving situation shown in Figure 2, the lane change of vehicle 1 has already been initiated, with vehicle 1 still on its starting lane F1. The emergency trajectory N corresponds to the standard trajectory S in terms of its position, so that vehicle 1 performs the lane change in activated emergency mode.

[0034] Vehicle 1 includes an environmental sensor system not shown, whereby a function of a number of environmental sensors of the environmental sensor system is also available in the activated emergency operation of vehicle 1.

[0035] The assistance system comprises a main control unit for automated driving and a secondary control unit for controlling vehicle 1 in emergency mode. During automated driving, the main control unit continuously determines the emergency trajectory N to be used in emergency mode and provides this to the secondary control unit. In activated emergency mode, the secondary control unit takes over the task of controlling vehicle 1. Thus, even in the event of an emergency mode caused by a failure of the main control unit, the assistance system is able to guide vehicle 1 to a safe state, in particular a safe standstill, according to the emergency trajectory N previously determined by the main control unit. Generally, the secondary control unit is designed to be less powerful than the main control unit.In particular, the auxiliary control unit is a control unit for vehicle dynamics stabilization and is designed to process satellite-based information and signals captured by a vehicle-mounted camera as an environmental sensor. Based on the satellite-based information, a more precise localization of vehicle 1 is possible than if the determination of the vehicle 1's instantaneous position were based on measured wheel speeds.

[0036] In the event of a relatively serious malfunction of the automated driving operation of vehicle 1, for example, a failure of the main control unit, the vehicle 1 retains access to the functions of the most essential environmental sensors in activated emergency mode. This division of resources enables vehicle 1 to remain controllable even without redundant environmental sensors in the event of a failure of the main control unit or a failure of an auxiliary control unit.

[0037] Both the main control unit and the auxiliary control unit of vehicle 1 are connected to a drive controller for automated driving operation and emergency operation, to a device for steering, braking and to a number of environmental sensors as well as other sensors.

[0038] In emergency mode, the function of at least one sensor, for example a camera, is available, whereby the starting lane F1 and the destination lane F2 are detected based on captured signals, in particular image signals. The camera's detection area is directed in front of vehicle 1, and while vehicle 1 is in motion, signals are continuously captured, which are also used to detect objects and obstacles in front of vehicle 1. This makes it possible to initiate collision avoidance and / or collision mitigation measures.

[0039] Using signals from the environmental sensors, the assistance system attempts to move the vehicle 1 in automated driving mode at a comparatively high travel speed, whereby the vehicle 1 is longitudinally and laterally controlled along the determined standard trajectory S.

[0040] According to the prior art, the standard trajectory S is used as the emergency trajectory N for the activated emergency operation, whereby the vehicle 1 is brought to a standstill with a predefined deceleration profile. In particular, the standard trajectory S and the emergency trajectory N specify not only a series of spatial coordinates along which the vehicle 1 is guided, but also information regarding a desired speed and acceleration profile along these spatial coordinates.

[0041] If vehicle 1 performs a lane change according to the standard trajectory S, during which the emergency operation of vehicle 1 is activated, there is a risk that vehicle 1 will be brought to a standstill during the lane change and thus come to a stop on the starting lane F1 and the destination lane F2, as shown in Fig. 1 is shown.

[0042] If vehicle 1 follows in activated emergency mode, as in Fig. As shown in Figure 2, if vehicle 1 follows the standard trajectory S and thus the emergency trajectory N with a reduced deceleration profile, and performs the lane change, then while vehicle 1 is indeed on the target lane F2, the lane change is performed without lateral and rear object detection. This poses a significant risk to other road users and exposes vehicle 1 to a comparatively high collision risk. For example, the target lane F2 may be occupied by other road users in the vicinity of vehicle 1 performing the lane change, and these other road users may not be detected or only detected relatively late. This danger increases with the travel time on the target lane F2 relative to the specified emergency trajectory N.Typically, in automated driving mode, vehicle 1 can change lanes to a destination lane F2, an exit lane not shown in detail, or a hard shoulder.

[0043] To optimize the comfort and safety of vehicle 1 and other road users during a planned or already initiated lane change, an approach is described below based on the following: Fig. 3 and Fig. The procedure described in section 4 is provided.

[0044] In automated driving mode, after a lane change has been planned or initiated, two emergency trajectories N are determined. One emergency trajectory N is used to bring vehicle 1 to a safe standstill on its starting lane F1 within a predetermined distance or time period. The other determined emergency trajectory N is used to bring vehicle 1 to a standstill on its destination lane F2 within a predetermined distance or time period.

[0045] According to the embodiment in Fig. 3. Vehicle 1 follows the determined emergency trajectory N on the starting lane F1, even though a lane change to the destination lane F2, represented by the standard trajectory S, is planned. Vehicle 1 is brought to a standstill according to the specified deceleration profile of the emergency trajectory N.

[0046] In particular, vehicle 1 is brought to a standstill in the starting lane F1 if the emergency trajectory N specifies that vehicle 1 can be decelerated within a specified distance or time period on the starting lane F1 without the lateral acceleration acting on vehicle 1 exceeding a specified comfort value, and without vehicle 1 having already penetrated the destination lane F2 by a specified depth, as in Fig. 4 is shown.

[0047] For example, the specified comfort value with regard to lateral acceleration lies in a range between 0.5 m / s². 2 and 3 m / s 2 .

[0048] Depending on the lateral acceleration and the penetration depth of vehicle 1 into the target lane F2, with a lane change already initiated, as decision criteria, a corresponding emergency trajectory N is selected, and vehicle 1 is brought to a safe standstill along this trajectory. The selected emergency trajectory N represents a target trajectory for longitudinal and lateral control of vehicle 1.

[0049] By using the camera's image signals as an environmental sensor, it is possible to detect collision-prone objects on the respective emergency trajectory N that were not captured during the initial determination of the trajectory. This makes it possible, for example, to avoid a collision between vehicle 1 and a potential collision object by applying stronger braking. The speed and / or acceleration profile of the emergency trajectory N is thus adapted to changing environmental conditions. The emergency trajectory N with the lowest collision risk, thus largely avoiding the need for emergency braking, is also selected. In addition to lateral acceleration or penetration depth, the emergency trajectory N with the low or no risk in critical situations is chosen. For example, a critical situation could arise from a relatively short-term obstacle, such as a road sign.B. a slow-moving or crossing vehicle or a stationary object, which are located on one of the emergency trajectories N.

[0050] Furthermore, the procedure provides that when the emergency operation of vehicle 1 is activated, a warning message is issued in vehicle 1, which is issued visually, audibly and / or haptically, for example by activating a reversible seat belt tensioner.

[0051] Depending on the country in which vehicle 1 is located, the hazard warning lights of vehicle 1 will be automatically switched on at the time the emergency operation is activated or at the time vehicle 1 comes to a standstill.

[0052] To determine the country where vehicle 1 is located, its current position is recorded using a position signal from a satellite-based positioning unit. The hazard warning lights are then activated according to the country and applicable regulations.

[0053] In addition, when vehicle 1 is stationary, a parking brake is automatically activated and a gear position for parking is engaged to secure vehicle 1 against rolling away. Reference symbol list 1 vehicle F1 lane F2 adjacent lane N Emergency trajectory S Standard trajectory

Claims

[1] Method for operating an assistance system for automated driving of a vehicle (1), which follows a determined standard trajectory (S) in longitudinal and lateral control, wherein an emergency trajectory (N) is continuously determined, along which the vehicle (1) is brought to a standstill in longitudinal and lateral control after activation of an emergency operation of the vehicle (1), characterized by , that, in the event of an impending or already initiated lane change of the vehicle (1) from a starting lane (F1) to a destination lane (F2) according to the determined standard trajectory (S), a decision is made, depending on the position of the vehicle on the determined standard trajectory (S), as to whether the vehicle (1) should be brought to a standstill on the starting lane (F1) or on the destination lane (F2) when emergency operation is activated and that the vehicle (1) is then brought to a standstill on the starting lane (F1) if an emergency trajectory (N) is planned by means of which the vehicle (1) is brought to a standstill on the starting lane (F1) within a specified distance and / or within a specified time period, and if a specified comfort value of a lateral acceleration acting on the vehicle (1) and a specified penetration depth of the vehicle (1) into the destination lane (F2) are not exceeded. [2] Method according to claim 1, characterized by , that the decision is made taking into account a risk of collision on the starting lane (F1) and / or the finishing lane (F2) and the vehicle (1) is brought to a standstill on the less dangerous lane (F1, F2). [3] Method according to any one of the preceding claims, characterized by, that after the planning or initiation of the lane change, two emergency trajectories (N) are continuously determined which bring the vehicle (1) to a standstill within the specified distance and / or within the specified time period on the starting lane (F1) or on the destination lane (F2). [4] Method according to any one of the preceding claims, characterized by , that when the emergency operation of the vehicle (1) is activated, the hazard warning lights of the vehicle (1) are automatically activated, depending on the country in which the vehicle (1) is located, either when the emergency operation is activated or when the vehicle (1) comes to a standstill. [5] Method according to any one of the preceding claims, characterized by , that a current position of the vehicle (1) is determined on the basis of signals received from a satellite-based positioning unit. [6] Method according to any one of the preceding claims, characterized by, that when the emergency operation of the vehicle (1) is activated, a warning message is issued in the vehicle (1) visually, audibly and / or haptically. [7] Method according to any one of the preceding claims, characterized by , that when the vehicle (1) comes to a standstill, the vehicle's parking brake (1) is activated and a corresponding gear stage is selected.

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