Evasive steering assist

Abstract

Control unit (201) for a vehicle (101), wherein the control unit (201) is configured, - to detect an obstacle (102) on a current trajectory of the vehicle (101); - to determine an available distance (601) next to the obstacle (102) for an evasive trajectory (111, 112); - to determine an evasive trajectory (111, 112) for the vehicle (101) with a target distance (531) next to the obstacle (102); wherein the target distance (531) -for available distances (601) smaller than a predefined maximum distance (602), except for a transition range corresponding to the available distance (601); - for available distances (601) greater than the predefined maximum distance (602), which corresponds to the maximum distance (602); and - in the transition range from an available distance (601) that is smaller than the predefined maximum distance (602) to an available distance (601) that corresponds to the maximum distance (602) that is smaller than the available distance (601); - to determine an indication that a driver of vehicle (101) initiated an evasive maneuver; and - depending on the evidence obtained and depending on the evasive trajectory obtained (111, 112), to initiate support for the evasive maneuver.

Description

[0001] The invention relates to a method and a corresponding device for assisting a driver of a vehicle during an evasive maneuver.

[0002] From EP 1 735 187 B1 an anti-collision system is known which assists the driver of a vehicle in carrying out an evasive maneuver around an obstacle.

[0003] To execute a stable and safe evasive maneuver, it is crucial that the driver receives support, particularly during the initial phase. This is because the vehicle's dynamic characteristics significantly influence the course of the entire maneuver during this initial phase. This document describes devices and methods that provide support to the driver, especially during the initial phase of an evasive maneuver.

[0004] Performing an evasive maneuver can potentially destabilize the vehicle. This document describes devices and procedures that assist the driver in performing an evasive maneuver by reducing or completely preventing vehicle vibrations.

[0005] DE 10 2008 016 377 A1 describes a method for operating a vehicle during an evasive maneuver. DE 10 2006 034 254 A1 describes a method for carrying out an evasive maneuver. DE 10 2007 027 495 A1 describes a method for assisting the driver of a motor vehicle with lateral control. DE 10 2011 080 789 A1 describes a method for controlling vehicle stability.

[0006] Evasive maneuver support is typically based on a previously determined evasive trajectory. Specifically, the support typically aims to ensure that the driver follows this trajectory. Furthermore, the determined trajectory allows for an evaluation of the driver's behavior during the evasive maneuver. This document describes devices and methods for determining an (potentially optimal) evasive trajectory that is highly likely to be followed by the driver. It also describes devices and methods for adjusting the level of support to ensure the driver follows the determined evasive trajectory.

[0007] According to one aspect, a control unit for a vehicle is described. The vehicle can be a single-track or two-track road vehicle, e.g., a passenger car, a truck, or a motorcycle. The control unit can include one or more of the features described in this document. The control unit is configured to detect an obstacle on the vehicle's current trajectory. For this purpose, the vehicle can acquire environmental data using one or more environmental sensors (e.g., one or more cameras, one or more radar sensors, and / or one or more LiDAR sensors, i.e., light detection and ranging sensors). The obstacle can be detected based on the environmental data. Examples of obstacles include another vehicle and / or another road user, such as a pedestrian.The obstacle may be located at a fixed position on the vehicle's trajectory, or the obstacle may change its location.

[0008] The control unit is further configured to determine an evasive trajectory for the vehicle to avoid the obstacle. This evasive trajectory can include a route (different from the current trajectory) that bypasses the obstacle. The control unit can be configured to determine multiple evasive trajectories, for example, a first trajectory to the left of the obstacle and a second (different) trajectory to the right.

[0009] The control unit is further configured to detect, at an initial point in time, an initial indication that the driver of the vehicle has initiated an evasive maneuver. The driver can initiate an evasive maneuver, in particular, by operating a steering device (e.g., the steering wheel) to move the vehicle onto a trajectory that deviates from its current one. The control unit is configured to detect an indication that the driver has operated the steering device to move the vehicle onto a different trajectory.

[0010] The first indication for initiating an evasive maneuver may include, for example, one or more of the following: the magnitude of a steering angle of the vehicle's steering device reaches or exceeds a predefined first steering angle threshold; the magnitude of a steering speed of the vehicle's steering device reaches or exceeds a predefined first steering speed threshold; the magnitude of a steering torque at the vehicle's steering device reaches or exceeds a predefined first steering torque threshold; and / or the magnitude of a steering acceleration of the vehicle's steering device reaches or exceeds a predefined first steering acceleration threshold; and / or the magnitude of a steering torque change of the vehicle's steering device reaches or exceeds a predefined first steering torque change threshold.and / or the amount of a steering angle change of the vehicle's steering device reaches or exceeds a predefined first steering angle change threshold.

[0011] Among the possible indicators that a driver is initiating an evasive maneuver, steering speed in combination with a change in steering torque is particularly useful, as these indicators allow for initiating an evasive maneuver at a very early stage. It can also be considered whether the steering speed and / or the change in steering torque occurred during "normal" driving or from a stationary phase, whereby "normal" driving typically exhibits curves in terms of steering angle, steering torque, and / or steering speed that occur during comfortable driving in the lane.

[0012] The one or more indicators for initiating an evasive maneuver can be determined, in particular, based on measurement data from one or more sensors. The steering angle, steering speed, steering acceleration, and / or steering torque can be determined, for example, by a steering sensor on the steering system. Alternatively or additionally, measurement data from a speed sensor and / or a yaw sensor of the vehicle can also be considered.

[0013] The control unit is further configured to initiate evasive maneuver support based on the initial indication and the determined evasive trajectory. Evasive maneuver support can be initiated at the first indication. The initial indication might, for example, show that an evasive maneuver has been initiated in a specific direction (e.g., left or right) around the obstacle. Support can then be initiated for the evasive trajectory determined for that direction.

[0014] Evasive maneuver support can include, for example, influencing the vehicle's steering system, depending on the determined evasive trajectory. In particular, the steering system can be adjusted to ensure the vehicle (tends to) follow the determined evasive trajectory. For this purpose, an additional torque (in addition to the steering torque applied by the driver) can be applied to the steering system. This additional torque can be determined and applied based on the determined evasive trajectory. Alternatively or additionally, evasive maneuver support can include applying braking force to one or more of the vehicle's wheels. By applying the brakes to individual wheels, steering the vehicle can be enabled.Thus, evasive maneuvers can be supported by interventions in the vehicle's driving dynamics. In particular, such interventions can also generate additional torque. In other words, evasive maneuver support can include a driving dynamics intervention that causes a yaw reaction in the vehicle. The strength of this yaw reaction can depend on the degree of evasive maneuver support.

[0015] In particular, the control unit can be configured to determine a deviation (or a measure of the deviation) between the vehicle's actual trajectory and the calculated avoidance trajectory. The applied additional torque can then depend on the calculated deviation (or the calculated measure of the deviation). The sign of the applied additional torque can depend on the sign of the deviation. For example, the additional torque can act in the same direction as the torque applied by the driver if the steering angle is insufficient to steer the vehicle onto the calculated avoidance trajectory. Conversely, the additional torque can act against the torque applied by the driver if the steering angle applied by the driver exceeds the steering angle required to follow the calculated avoidance trajectory. The magnitude of the applied additional torque can increase with the magnitude of the calculated deviation.In particular, no additional torque can be applied if the driver is already driving along the determined evasive trajectory. Overall, the applied additional torque can assist the driver if the driver steers too little or too much, or if the driver steers back too late in a second phase of the evasive maneuver.

[0016] The control unit can be further configured to determine, at a second point in time, a second indication that no evasive maneuver is being initiated. This second point in time follows the first. At the second point in time, automatic evasive assistance may already have been initiated. In particular, at the second point in time, an indication may be determined that the first indication was erroneous and that the driver did not intend to initiate an evasive maneuver at all. Depending on the second indication determined, the control unit can then be configured to terminate the evasive assistance.

[0017] Considering two consecutive indicators allows for a relatively sensitive initial indicator to be used for detecting the initiation of an evasive maneuver. This enables the control unit to begin supporting the maneuver at an early stage. This is advantageous because the effectiveness of an actual evasive maneuver depends particularly on its initial phase. Specifically, this approach increases the likelihood that the driver will follow the predetermined (potentially optimal) evasive trajectory.

[0018] The second indicator ensures that no evasive assistance is provided if the driver has not initiated an evasive maneuver or if the driver has aborted the maneuver. In particular, it ensures that the driver retains the authority to decide whether to execute an evasive maneuver and / or an alternative course of action. An aborted evasive maneuver can be detected, for example, if the steering angle is no longer increased or is reduced, and / or if the steering force or torque is applied in the opposite direction.

[0019] The second indication that no evasive maneuver has been initiated may include one or more of the following: The magnitude of the steering angle of the vehicle's steering device does not reach or exceed a predefined second steering angle threshold, where the second steering angle threshold is greater than the first steering angle threshold; the magnitude of the steering speed of the vehicle's steering device does not reach or exceed a predefined second steering speed threshold, where the second steering speed threshold is greater than the first steering speed threshold; the magnitude of the steering torque at the vehicle's steering device does not reach or exceed a predefined second steering torque threshold, where the second steering torque threshold is greater than the first steering torque threshold;and / or the magnitude of the steering acceleration of the vehicle's steering device does not reach or exceed a predefined second steering acceleration threshold, wherein the second steering speed threshold is greater than the first steering speed threshold; and / or the magnitude of the steering torque change of the vehicle's steering device does not reach or exceed a predefined second steering torque change threshold, wherein the second steering torque change threshold is greater than the first steering torque change threshold; and / or the magnitude of the steering angle change of the vehicle's steering device does not reach or exceed a predefined second steering angle change threshold, wherein the second steering angle change threshold is greater than the first steering angle change threshold.

[0020] The inclusion of a second index, which may trigger the termination of evasive maneuver support, allows for the use of relatively small initial thresholds, enabling the use of more sensitive initial indicators for initiating evasive maneuver support. For example, smaller initial thresholds can be used instead of the second thresholds. If the second thresholds are not reached, evasive maneuver support can be terminated.

[0021] The second indication that no evasive maneuver has been initiated can include the failure to reach or exceed one or more of the second thresholds within a predefined time interval from the first time point. This limits the period during which evasive assistance is provided, even if no evasive maneuver has actually been initiated, to the predefined time interval. This predefined time interval could, for example, be 100 ms or less.

[0022] Alternatively or additionally, the second indicator that no evasive maneuver has been initiated may include one or more of the following: the amount of the steering angle of the vehicle's steering system reaches or exceeds a predefined maximum steering angle threshold; the amount of the steering speed of the vehicle's steering system reaches or exceeds a predefined maximum steering speed threshold; the amount of the steering torque at the vehicle's steering system reaches or exceeds a predefined maximum steering torque threshold; and / or the amount of steering acceleration of the vehicle's steering system reaches or exceeds a predefined maximum steering acceleration threshold. Considering one or more maximum thresholds makes it possible to detect uncontrolled driver behavior.Such uncontrolled behavior cannot be considered a deliberate initiation of an evasive maneuver.

[0023] Alternatively or additionally, the second indication that no evasive maneuver is being initiated can be that the magnitude of the steering torque, steering angle, and / or steering speed of the vehicle falls below a predefined abort threshold. A reduced steering torque and / or a reduced (possibly negative) steering angle can detect that the driver intends to abort the initiation of an evasive maneuver.

[0024] When determining the indicators described in this document, the magnitude of the steering angle can be calculated based on a current steering angle and on an average steering angle. Specifically, the magnitude of the steering angle relative to the average steering angle can be determined. Similarly, the magnitude of the steering torque can be calculated based on a current steering torque and on an average steering torque. Specifically, the magnitude of the steering torque relative to the average steering torque can be determined. In other words, delta values ​​can be calculated and compared with a threshold value. This is advantageous because it allows the initiation of an evasive maneuver to be detected even when cornering. This is further enhanced by considering the steering speed and / or steering acceleration.

[0025] The control unit can be configured to determine a third indicator that the vehicle is in a dynamic state. Like the other indicators, this third indicator can be determined using measurement data from one or more of the vehicle's sensors.The third indication that the vehicle is in a dynamic state can include one or more of the following: the steering torque at the vehicle's steering mechanism exhibits one or more peaks over time; the steering speed of the vehicle's steering mechanism exhibits one or more peaks over time; the yaw rate of the vehicle exhibits a variance that reaches or exceeds a yaw rate variance threshold; the lateral acceleration of the vehicle exhibits a variance that reaches or exceeds a lateral acceleration variance threshold; and / or the steering angle of the vehicle's steering mechanism exhibits a variance that reaches or exceeds a steering angle variance threshold. Typically, the vehicle returns to a non-dynamic ("normal") state only after the dynamic state has subsided.

[0026] Depending on the third indicator, the control unit can then be configured to prevent or abort the assistance of the evasive maneuver. This ensures that no further input from the control unit is introduced into the vehicle.

[0027] The control unit can be further configured to cancel or prevent evasive maneuver assistance if the vehicle decelerates to or exceeds a predefined deceleration threshold; and / or if the vehicle accelerates to or exceeds a predefined acceleration threshold. In other words, automatic evasive maneuver assistance can be prevented during relatively strong braking or acceleration maneuvers by the driver. Such braking / acceleration maneuvers can be interpreted as further evidence that the driver does not intend to initiate an evasive maneuver (even a purely evasive one). It should also be noted that substantial longitudinal and lateral accelerations cannot typically be transmitted to the vehicle's tires simultaneously.

[0028] According to another aspect, a method for assisting a vehicle driver during an evasive maneuver is described. The method includes detecting an obstacle on the vehicle's current trajectory. It further includes determining an evasive trajectory for the vehicle to avoid the obstacle. Additionally, the method includes determining, at a first point in time, an initial indication that the vehicle driver is initiating an evasive maneuver. Depending on this initial indication and the determined evasive trajectory, automatic assistance for the evasive maneuver can then be provided. The method further includes determining, at a second point in time, a second indication that no evasive maneuver has been initiated. This second point in time follows the first.Depending on the second piece of evidence obtained, support for the evasive maneuver can then be terminated.

[0029] According to another aspect, a control unit for a vehicle is described. The control unit can include one or more of the features described in this document. The control unit is configured to detect an obstacle on the vehicle's current trajectory. The control unit is further configured to determine (at least) an evasive trajectory for the vehicle to avoid the obstacle. Additionally, the control unit is configured to determine an indicator (e.g., the first indicator mentioned above) that the driver of the vehicle is initiating an evasive maneuver. Furthermore, depending on the determined indicator and the determined evasive trajectory, the control unit is configured to initiate assistance for the evasive maneuver.

[0030] The control unit can be further configured to reduce the level of assistance during the evasive maneuver. Specifically, the level of assistance can be relatively high in the initial phase of the maneuver and reduced in later phases. This ensures optimal support for the driver during the evasive maneuver (particularly through intensive assistance in the initial phase) while simultaneously reducing the potential transmission of vibrations to the vehicle (by reducing the level of assistance later in the maneuver). Furthermore, this allows for a smooth handover to the driver.The reduction in the level of support also reflects the fact that the vehicle's environmental data typically exhibits relatively high reliability in the initial phase of the evasive maneuver, and the reliability of the environmental data decreases along the course of the evasive maneuver.

[0031] The evasive maneuver can consist of a first phase and a subsequent second phase. Specifically, the evasive maneuver can be divided into two phases. During the first phase, the vehicle's heading angle may increase. In other words, during the first phase, the vehicle's direction of travel may change from its direction of travel before the evasive maneuver was initiated. During the second phase, the vehicle's heading angle may decrease. In other words, during the second phase, the vehicle's direction of travel may change back towards its direction of travel before the evasive maneuver was initiated.

[0032] Alternatively or additionally, the steering angle of the vehicle's steering system in the first phase can have a first sign (relative to the initial steering angle before initiating the evasive maneuver). Furthermore, the steering angle of the vehicle's steering system in the second phase can have a second sign (relative to the initial steering angle before initiating the evasive maneuver). The first and second signs can be opposite. In particular, the first and second phases can be distinguished by a reversal of the sign of the steering angle. Alternatively or additionally, the lateral acceleration of the vehicle can have a first sign in the first phase and a second sign in the second phase, with the first and second signs being opposite.

[0033] After the second phase, relatively small steering movements typically follow, with a pattern typical for a "normal" drive.

[0034] The level of assistance can be greater in the first phase (e.g., the initial phase of the evasive maneuver) than in the second phase (e.g., the final phase). Specifically, the level of assistance can have a maximum value in the first phase. Furthermore, the level of assistance can be continuously reduced in the second phase, starting from this maximum value. This allows for an optimal balance between assisting the evasive maneuver and handing control back to the driver.

[0035] The control unit can be further configured to prevent support for a subsequent evasive maneuver, at least for a predefined period, during a phase (possibly immediately) following the execution of the evasive maneuver. Performing an evasive maneuver can potentially introduce vibrations or excitations into the vehicle. Preventing support for a subsequent evasive maneuver that directly follows a previous one can ensure that automatic evasive assistance is only provided when the vehicle is stable.

[0036] As explained above, evasive maneuver assistance can involve applying additional torque to the vehicle's steering system. The magnitude of this additional torque can depend on the level of assistance provided. In other words, the control unit can be configured to reduce the amount of additional torque applied during the evasive maneuver, allowing for the application of the maximum possible torque at the beginning and a subsequent (potentially continuous) reduction of the additional torque during the second phase.

[0037] The control unit can be configured to determine a deviation (or a measure of deviation) between the vehicle's actual trajectory and the calculated evasive trajectory. The actual applied additional torque can also depend on the calculated deviation. For example, a maximum possible additional torque can be determined via the level of assistance. Alternatively or additionally, a proportionality factor with respect to the applied additional torque can be determined via the level of assistance. As outlined in this document, the maximum possible additional torque and / or a proportionality factor can be modified at different stages of an evasive maneuver.The actual additional torque applied can then be determined within the framework of the additional torque possible in a current phase of the evasive maneuver and / or using the factor valid for the current phase of the evasive maneuver, depending on the determined deviation between the actual trajectory of the vehicle and the determined evasive trajectory.

[0038] According to another aspect, a method for assisting a vehicle driver during an evasive maneuver is described. The method includes detecting an obstacle on the vehicle's current trajectory. It further includes determining an evasive trajectory for the vehicle to avoid the obstacle. In addition, the method includes identifying an indication that the vehicle driver has initiated an evasive maneuver. Furthermore, the method includes providing assistance with the evasive maneuver based on the identified indication and the determined evasive trajectory. Specifically, evasive maneuver assistance can only be provided if there is an indication that the driver has initiated an evasive maneuver. The degree or intensity of the assistance can be reduced as the evasive maneuver progresses.

[0039] According to another aspect, a control unit for a vehicle is described. The control unit can include one or more of the features described in this document. In particular, the control unit is configured to detect an obstacle on the vehicle's current trajectory. Furthermore, the control unit is configured to determine an available distance (e.g., a width of the clear area) next to the obstacle for an evasive trajectory. The available distance can encompass the width of the maneuvering space for the vehicle. Specifically, an available distance to the left and / or right of the obstacle can be determined for a left and / or right evasive trajectory.

[0040] The available clearance next to the obstacle can depend on one or more of the following: the edge of the road or lane being traveled on; the predicted position of one or more other road users (e.g., other vehicles or pedestrians); and / or a safety distance to the obstacle, the road edge, or the other road users. These safety distances can depend on prediction uncertainties (typically, safety distances increase with increasing prediction uncertainties). Furthermore, the safety distances can depend on the measurement accuracy and / or the object's movement (crossing movements are typically less predictable than movements in the direction of travel) and / or the control accuracy of a controller providing evasive maneuver support.

[0041] The control unit is further configured to determine an evasive trajectory for the vehicle with a target distance from the obstacle. This target distance can be less than a predefined maximum distance for at least one available distance, or equal to the available distance for at least one available distance. Furthermore, the target distance can be greater than the predefined maximum distance for at least one available distance, or equal to the maximum distance for at least one available distance. In other words, the target distance for available distances can be less than a predefined maximum distance, less than or equal to the available distance. Additionally, the target distance for available distances can be greater than the predefined maximum distance, less than or equal to the maximum distance. In particular, the target distance can equal the available distance if it is less than the predefined maximum distance.This can apply to all available distances that are smaller than the predefined maximum distance. Furthermore, the target distance can correspond to the maximum distance if the available distance is greater than or equal to the predefined maximum distance. This can apply to all available distances that are greater than or equal to the predefined maximum distance.

[0042] Considering the aforementioned target distance when determining the evasive trajectory allows for the calculation of a safe trajectory with the lowest possible lateral acceleration and thus the lowest possible use of road friction. Furthermore, by defining the target distance, an evasive trajectory can be determined that is highly likely to correspond to the trajectory desired by the driver. The trajectory desired by a driver can be determined through a study with test subjects. For this purpose, the evasive trajectories actually driven by a driver can be recorded and analyzed. Based on the recorded evasive trajectories, one or more parameters for "desired" trajectories can be determined. These one or more statistically determined parameters can then be considered when calculating an evasive trajectory.

[0043] By taking the aforementioned target distance into account, a high degree of agreement between the actual trajectory and the determined evasive trajectory can be achieved (on average), resulting in a low degree of influence on the steering system and / or a low degree of required driver override. This allows the driver to be optimally supported during the evasive maneuver.

[0044] As explained above, the control unit can be further configured to detect an indication (e.g., the first indication) that a driver of the vehicle is initiating an evasive maneuver. Furthermore, depending on the detected indication and the determined evasive trajectory, assistance for the evasive maneuver can be initiated.

[0045] The maximum distance can depend on one or more vehicle characteristics. In particular, the maximum distance can depend on the vehicle's track width. Alternatively or additionally, the maximum distance can depend on the vehicle's (potentially required) lateral acceleration. Alternatively or additionally, the maximum distance can depend on the vehicle's track offset relative to the obstacle.

[0046] As explained above, evasive maneuver support can include influencing the vehicle's steering system, depending on the determined evasive trajectory. Alternatively or additionally, evasive maneuver support can include one or more of the following measures: adjusting a vehicle control system to increase vehicle stability (e.g., an electronic stability program); and / or preventing, canceling, and / or reducing automatic braking interventions (e.g., an automatic braking system). This can increase safety when executing an evasive maneuver.

[0047] The control unit can be configured to predict a changing position of the obstacle. The obstacle's position can change from the moment it is detected. In particular, the control unit can be configured to recognize, based on environmental data, that the obstacle's position is changing relative to the vehicle's position. Furthermore, one or more future positions of the vehicle can be predicted. For example, the obstacle's trajectory can be predicted. The control unit can be configured to determine the evasive trajectory depending on the predicted position and / or the predicted trajectory of the obstacle. A safety distance to the predicted position of the obstacle can also be taken into account. This safety distance can increase with increasing prediction uncertainty.By taking the predicted position into account, it can be ensured that the determined evasive trajectory allows for safe avoidance of the obstacle. In other words, to prevent the vehicle from colliding with the obstacle when traveling along the evasive trajectory, the future, i.e., predicted, position of the obstacle can be considered in addition to its current position when determining the evasive trajectory.

[0048] The control unit can be further configured to prevent assistance with the evasive maneuver, for example, if the available distance (next to the obstacle) is less than or equal to a predefined minimum distance; and / or if another obstacle is detected or predicted on the determined evasive trajectory. This ensures that automatic assistance is only provided for safe evasive maneuvers.

[0049] According to another aspect, a method for assisting a vehicle driver during an evasive maneuver is described. The method involves detecting an obstacle on the vehicle's current trajectory and determining the available distance beside the obstacle for an evasive trajectory. An evasive trajectory can then be determined for the vehicle with a target distance beside the obstacle. This target distance can correspond to the available distance if it is less than a predefined maximum distance, and to the maximum distance if it is greater than or equal to the predefined maximum distance.

[0050] The procedure further includes determining an indication that the driver of the vehicle is initiating an evasive maneuver, and providing support for the evasive maneuver, depending on the indication determined and depending on the evasive trajectory determined.

[0051] According to another aspect, a control unit for a vehicle is described. The control unit can include one or more of the features described in this document. The control unit can be configured to detect an obstacle on the vehicle's current trajectory. Furthermore, the control unit can be configured to determine an evasive trajectory for the vehicle to avoid the obstacle. Additionally, the control unit can be configured to detect an indication that the driver of the vehicle is initiating an evasive maneuver.

[0052] The control unit is further configured to determine a target steering angle for the vehicle's steering system based on the calculated evasive trajectory. Additionally, the actual steering angle of the vehicle's steering system can be determined. This actual steering angle can be detected by a steering sensor. The steering sensor can be located in various positions within the vehicle. For example, it can be located on the steering wheel, a tie rod, and / or at the wheel.

[0053] Depending on the determined indicator, the target steering angle, and the actual steering angle, the control unit can then initiate assistance for the evasive maneuver. In other words, the target steering angle and the actual steering angle can be taken into account for automatic evasive maneuver assistance. Specifically, the degree of assistance can depend on the target steering angle and the actual steering angle.

[0054] Considering the target and actual steering angles during automatic evasive maneuver support allows deviations to be assessed before substantial lateral acceleration errors, heading angle errors, and / or steering position errors develop. Direct feedback can be provided to the driver regarding such deviations. This reduces any potential phase delay (or time lag) between the current state of the evasive maneuver and the applied support. In particular, this enables reliable and phase-consistent support for highly dynamic driving maneuvers. Furthermore, lateral acceleration errors, heading angle errors, and / or steering position errors can also be taken into account when determining the level of automatic evasive maneuver support.

[0055] The control unit can be further configured to determine, based on the target steering angle and the actual steering angle, a measure of the deviation of the vehicle's actual trajectory (i.e., the vehicle's current trajectory) from the calculated evasive trajectory. Taking the steering angle into account allows for the reduction of phase delays. The degree of evasive maneuver support can then be determined based on the calculated deviation measure. This ensures optimal support for the evasive maneuver at all times.

[0056] For example, a dampening torque can be applied to reduce the driver's steering input if the actual steering angle is greater than the target steering angle. In other words, if the steering is too abrupt, an additional damping torque can be applied to help the driver avoid unnecessarily introducing excessive dynamics into the vehicle. Alternatively or additionally, a steering torque that assists the steering input can be applied if the actual steering angle is less than the target steering angle. In other words, if the driver is not steering quickly enough, a reinforcing steering torque can be applied to help the driver increase the steering angle quickly enough. Furthermore, an additional torque can be applied in the second phase of the evasive maneuver to encourage the driver to steer back in time.

[0057] The control unit may be configured not to provide any assistance during the evasive maneuver when driving on or along the determined avoidance trajectory. In particular, no additional torque may be applied in this case.

[0058] As explained above, evasive maneuver support can involve applying an additional torque to the vehicle's steering system. The magnitude of this additional torque can depend on the determined degree of deviation. Furthermore, the magnitude of the additional torque can depend on the control stiffness of the evasive maneuver support controller.

[0059] The control unit can be configured to determine the deviation measure based on one or more of the following vehicle state variables: a target lateral acceleration and an actual lateral acceleration; a target lateral velocity and an actual lateral velocity; a target heading angle and an actual heading angle; and / or a target lateral offset and an actual lateral offset. The deviation measure can then be determined based on a weighted average of a multitude of vehicle state variables, with the steering angle also being considered a vehicle state variable.

[0060] The control unit may be configured to determine one or more of the state variables, in particular the actual lateral acceleration, the actual lateral velocity or the actual heading angle and / or the actual lateral displacement, using odometric methods.

[0061] This allows the state variables to be determined efficiently.

[0062] The control unit can be configured to determine the target steering angle from the calculated avoidance trajectory using an inverse vehicle model (e.g., a single-track model and / or an actuator model). The inverse single-track model can be approximated using a comparable feedforward control method. Specifically, a target lateral offset can be determined from the calculated avoidance trajectory at any time and / or position along the trajectory, thus guiding the vehicle onto the calculated avoidance trajectory. By differentiating with respect to time and / or distance, the target lateral velocity (or target heading angle) can be determined, and by further differentiation with respect to time and / or distance, the target lateral acceleration can be calculated. The inverse single-track model of the vehicle then allows the target steering angle to be calculated from the target lateral acceleration.In this way, all target state variables of the vehicle can be determined from the calculated avoidance trajectory.

[0063] The control unit can be configured to regulate the degree of evasive maneuver support based on the difference between the target steering angle and the actual steering angle. A control algorithm (e.g., a proportional (P), integral (I), and / or differential (D) controller, and / or a state controller with an observer) can be used for this purpose. In particular, the degree of evasive maneuver support can be regulated depending on the determined degree of deviation. Thus, the differences of one or more other vehicle state variables can be taken into account. This ensures that the vehicle is guided along the determined evasive trajectory. Typically, the driver can override the evasive maneuver support at any time using appropriate measures.

[0064] The control unit can be further configured to determine the target steering angle and the actual steering angle (and, if applicable, other state variables) during an evasive maneuver for a sequence of time points. The degree of evasive maneuver support can be adjusted depending on the determined target and actual steering angles. In particular, the degree of support can be adjusted at each time point in the sequence of time points (e.g., using the control method described in this document).

[0065] The control unit can be configured to determine the target steering angle based on a phase-shifted evasive trajectory. Specifically, the determined evasive trajectory can be shifted forward in time compared to the trajectory actually driven. The target steering angle calculated from such a shifted evasive trajectory can thus correspond to a target steering angle that is actually advanced in time. This phase shift allows for the consideration and compensation of delays when calculating the required assistance for the evasive maneuver. Consequently, the quality of the assistance can be improved.

[0066] According to another aspect, a method for assisting a vehicle driver during an evasive maneuver is described. This method includes detecting an obstacle on the vehicle's current trajectory and determining an evasive trajectory for the vehicle to avoid the obstacle. The method further includes determining an indicator (e.g., the first indicator) that the vehicle driver is initiating an evasive maneuver. Additionally, the method includes determining a target steering angle for the vehicle's steering system, based on the determined evasive trajectory, as well as determining the actual steering angle of the vehicle's steering system (e.g., based on measurement data from one or more vehicle sensors). Then, depending on the determined indicator, the target steering angle, and the actual steering angle, automatic assistance for the evasive maneuver can be provided.

[0067] According to another aspect, a vehicle (e.g. a passenger car, a truck or a motorcycle) is described that includes a control unit described in this document.

[0068] Another aspect described is a software (SW) program. The SW program can be configured to run on a processor (e.g., on a vehicle's control unit) and thereby execute one or more of the procedures described in this document.

[0069] Another aspect describes a storage medium. This storage medium can include a software program configured to run on a processor and thereby execute one or more of the procedures described in this document.

[0070] It should be noted that the methods, devices, and systems described in this document can be used both alone and in combination with other methods, devices, and systems described in this document. Furthermore, any aspect of the methods, devices, and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined with one another in a variety of ways.

[0071] The invention will now be described in more detail using exemplary embodiments. Fig. 1. An example situation for an evasive maneuver; Fig. 2. A block diagram of selected components of a vehicle; Fig. 3 a flowchart of an exemplary procedure to support an evasive maneuver; Fig. 4 an exemplary course of steering speed during an evasive maneuver; Fig. 5a an example of an evasive trajectory; Fig. 5b an exemplary division of an evasive maneuver into a multitude of phases; Fig. 6 an exemplary characteristic curve for determining the planning distance to an obstacle; Fig. 7a an exemplary model of the state variables of a vehicle during an evasive maneuver; and Fig. 7b Exemplary components of a control unit to support an evasive maneuver.

[0072] As stated at the outset, this document deals with a method and a corresponding device for assisting the driver of a vehicle during an evasive maneuver. Fig. Figure 1 illustrates an example of an evasive maneuver. Vehicle 101 (also referred to as the ego vehicle) is traveling in lane 104 of a road 103 and is approaching an obstacle 102 (e.g., a relatively slow-moving or stationary vehicle). Vehicle 101 may then have the option of braking to avoid a collision with the obstacle 102. Alternatively or additionally (e.g., if there is insufficient braking distance available), vehicle 101 can avoid the obstacle by following an evasive trajectory 111, 112. The evasive trajectory 111, 112 typically depends on the available space next to the obstacle 102. The available space next to the obstacle 102 is usually limited, which is why... Fig. 1 is represented by the boundaries 105, 106.

[0073] Vehicle 101 may be equipped to assist its driver in performing an evasive maneuver. Such a driver assistance system (DAS) may be referred to as an evasive steering assist. Fig. Figure 2 shows selected components of the vehicle 101 for providing an evasive steering assist system. The vehicle 101 includes one or more environmental sensors 202 configured to acquire environmental data. This environmental data includes information about the area surrounding the vehicle 101. Typically, at least one environmental sensor 202 is configured to acquire the area in front of the vehicle 101. The one or more environmental sensors 202 include, for example, one or more cameras, one or more radar sensors, and / or one or more LiDAR sensors. The environmental data acquired by the environmental sensors 202 can be transmitted to a control unit 201 of the vehicle 101. The Fig. The vehicle 101 shown in Figure 2 comprises one or more environmental sensors 202 configured to detect the area in front of the vehicle 101. The vehicle 101 may also include one or more environmental sensors (not shown) configured to detect the area behind the vehicle 101.

[0074] The control unit 201 is configured to detect an obstacle 102 on the current trajectory of vehicle 101 based on environmental data. Furthermore, the control unit 201 can be configured to issue a warning regarding the obstacle 102 to the driver (e.g., via an audible and / or visual output from vehicle 101). The control unit 201 can also be configured to initiate one or more collision mitigation and / or collision avoidance measures. These measures can be made dependent on an action by the driver of vehicle 101. If the driver takes no action (e.g., does not even press the brake pedal), the control unit 201 can still initiate braking of vehicle 101 with a specific deceleration to mitigate the consequences of a collision.If the driver presses the brake pedal, the control unit 201 can cause the vehicle 101 to be braked with the required deceleration.

[0075] Alternatively or additionally, control unit 201 can be configured to assist the driver during an evasive maneuver. This is in Fig. The vehicle 101 shown in Figure 2 comprises a steering wheel (as an example of a general steering device) 203, which is connected to a steering gear 207 via a steering rod 204. A steering sensor 205 is configured to detect any action of the steering wheel 203. In particular, the steering sensor 205 can be configured to detect the deflection of the steering wheel 203 over time (and / or a steering angle and / or a steering torque over time). For this purpose, the steering angle of the steering wheel 203 can be recorded at a sequence of time points, optionally at a specific sampling rate. The data recorded by the steering sensor 205 can be referred to as steering data.

[0076] The vehicle 101 further includes a steering assistance unit 206 (e.g., a servo device) designed to assist the driver during steering maneuvers. Specifically, the steering assistance unit 206 is designed to apply additional steering forces (in addition to the steering forces applied by the driver). This makes steering easier for the driver. The steering assistance unit 206 may, for example, include an electric motor or a pump. Alternatively or additionally, the steering assistance unit 206 may be designed to apply additional steering forces by applying braking forces to individual wheels of the vehicle 101.

[0077] The control unit 201 can be set up, which is in Fig. 3. To execute the procedures shown in step 300. As already explained above, the control unit 201 can be configured to detect an obstacle 102 on the current trajectory of the vehicle 101 (step 301).

[0078] Furthermore, the control unit can be configured (especially after detection of an obstacle 102) to determine one or more evasive trajectories 111, 112 (steps 302). The one or more evasive trajectories 111, 112 can be determined taking into account the environmental data. Among other things, the available space for carrying out an evasive maneuver can be determined and considered when determining the evasive trajectories 111, 112. As in Fig. As shown in Figure 1, a left evasive trajectory 112 (passing obstacle 102 on the left) and / or a right evasive trajectory 111 (passing obstacle 102 on the right) can be determined.

[0079] The control unit 201 is further configured to determine, based on the steering data, whether the driver is initiating an evasive maneuver (step 303). If this is not the case, one or more updated evasive trajectories 111, 112 can be determined. Current environmental data can be taken into account (in particular, the updated position of the obstacle 102 relative to the vehicle 101). If the driver has initiated an evasive maneuver, the evasive steering assist can be activated (step 304). In other words, if it is detected that the driver has initiated an evasive maneuver, the control unit 201 can assist the driver in carrying out the maneuver. Specifically, the control unit 201 can cause the steering assist unit 206 to apply additional steering force, which helps the driver to drive along one of the previously determined evasive trajectories 111, 112.For example, if the driver initiates a left evasive maneuver, the previously determined left evasive trajectory 112 can be selected. Conversely, if the driver initiates a right evasive maneuver, the previously determined right evasive trajectory 111 can be selected. The additional steering force applied to assist the evasive maneuver can depend on how much the actual trajectory deviates from the selected evasive trajectory 111 or 112.

[0080] The evasive steering assist thus supports the driver in carrying out an evasive maneuver in a collision-critical situation. The control unit 201 can attempt to induce the driver to travel along the selected evasive trajectory 111, 112 by regulating the additional steering force. To achieve this, the initial phase of the evasive maneuver is particularly important. In other words, when executing an evasive maneuver, it is especially important that the driver is supported in the initial phase of the maneuver in bringing the vehicle onto the specified evasive trajectory 111, 112. On the other hand, this is typically difficult for a driver because, due to the vehicle dynamics characteristics of the vehicle 101, the yaw response of the vehicle 101 is delayed in the highly dynamic range.

[0081] To enable evasive steering assistance to begin as soon as the driver initiates the evasive maneuver, i.e., as soon as the driver begins to steer, it is crucial to detect the driver's steering input very quickly. However, reliable detection of driver steering input typically only occurs with relatively large steering movements. To nevertheless react to driver steering input as quickly as possible, this document proposes activating the evasive steering assistance at the first sign or indication of steering input and, if necessary, deactivating it if the steering input is not confirmed. Potential indicators of steering input can be determined based on the steering angle, steering torque, steering speed, and / or steering acceleration. One possible indicator is when the steering angle changes by more than a predefined steering angle threshold, and / or when the steering torque (or acceleration) exceeds a certain threshold.The evasive steering assist is activated when the steering torque rises and reaches or exceeds a predefined torque threshold, and / or when the steering speed reaches or exceeds a predefined speed threshold. By deactivating the evasive steering assist if steering input is not confirmed, the activation thresholds can be set relatively low, allowing the evasive steering assist to be activated at a relatively early stage.

[0082] This is in Fig. 4 illustrates. Fig. Figure 4 shows the curve 403 of the steering speed 402 over time 401 in the initial phase of an evasive maneuver. The starting point is "normal" driving in a lane. As soon as the steering speed 402 reaches a first speed threshold 404, the evasive steering assist can be activated (i.e., at time 405). By reaching or exceeding the second speed threshold 406 (possibly within a predefined time interval) at time 407, the steering input is confirmed, allowing the evasive steering assist to remain active. If the second speed threshold 406 is not reached (possibly within the predefined time interval), the steering input is not confirmed. This can then lead to the evasive steering assist being terminated.

[0083] Fig. Figure 4 illustrates that the two-stage activation / deactivation of the evasive steering assist makes it possible to use a relatively low threshold value 404, thus shifting the activation time 405 of the evasive steering assist to a relatively early stage of the evasive maneuver. This allows the driver of the vehicle to be supported in the early initial phase of the evasive maneuver, thereby enabling improved guidance along the selected evasive trajectory 111, 112.

[0084] As in Fig. As shown in Figure 4, a steering input may not be confirmed if the driver aborts the steering maneuver. An indication of aborted steering is that the steering speed does not reach or exceed the second speed threshold value 406. Aborted steering may occur, for example, during a brief course correction of the vehicle 101.

[0085] A steering failure may also occur if the driver steers excessively. In particular, a failure may occur if the steering angle reaches or exceeds a certain maximum threshold. Furthermore, a failure may occur if the steering speed reaches or exceeds a certain maximum threshold.

[0086] Alternatively or additionally, a steering failure may occur if the steering process is not continued swiftly. In particular, a failure may occur if the steering torque or steering speed 402 decreases sharply or becomes very small and / or changes sign. Furthermore, a failure may occur if the steering speed 402 does not reach the second speed threshold 406 (i.e., a confirmation threshold) within a predefined time interval after activation of the evasive steering assist.

[0087] Alternatively or additionally, a failure to confirm steering may occur if there is further evidence of the aborting of the evasive maneuver (e.g., strong braking or acceleration).

[0088] As explained above, steering input in a stable vehicle can be detected based on changes in steering torque and / or steering angle (steering speeds). Using change parameters or delta values ​​allows for the detection of steering input in curves. This can be achieved by subtracting the mean values ​​of the steering angle or steering torque. A stable vehicle is typically characterized by the absence of steering torque peaks and / or steering speed peaks. Furthermore, a stable vehicle is typically characterized by approximately constant yaw rate, lateral acceleration, and / or steering angle. Detection of any indication of a dynamic vehicle may lead to the termination or non-activation of the evasive steering assist system.

[0089] This document describes a device (in particular a control unit 201) for evasive steering assistance, which is configured to detect the surroundings of a vehicle 101 and to determine the vehicle's state. The device can generate additional steering forces or similar vehicle dynamics interventions via an actuator 206. Evasive steering assistance supports the driver in carrying out an evasive maneuver in collision-critical situations. The assistance can begin at the first sign or indication of the driver initiating steering. However, the assistance can be deactivated if the steering initiation is not confirmed. This allows for timely activation of the assistance. In particular, the assistance can thus support the driver in initiating steering even before the steering maneuver is complete.

[0090] As explained above, it is typically important for the entire evasive maneuver that the beginning of the maneuver corresponds as closely as possible to the selected evasive trajectory 112. However, it is particularly difficult for the driver to initiate the steering input for the desired trajectory at the beginning of the evasive maneuver because, due to the vehicle's dynamic characteristics 101, the yaw response is delayed in the highly dynamic range. Assistance is therefore particularly needed at the beginning of the evasive maneuver, especially since evasive maneuvers are relatively infrequent and thus unfamiliar to the driver. To prevent repeated interventions by the evasive assist system from causing vehicle vibrations, this document proposes a pause after each intervention to allow any vibrations to subside. Fig. Figure 5a shows the evasive trajectory 112 determined by the control unit 201 and an evasive trajectory 512 actually driven by the driver, which typically differs from the determined and selected evasive trajectory 112. The driven evasive trajectory 512 (or the driven evasive maneuver) can be divided into a number of phases. In particular, the evasive maneuver includes a first phase (or an initial phase) in which the driver steers the vehicle 101 into the evasive trajectory 512 to avoid the obstacle 102. Furthermore, the evasive maneuver includes a second phase (or a final phase) in which the driver returns the vehicle 101 to its original direction of travel.

[0091] Fig. Figure 5b shows an example of how an evasive maneuver can be divided into a multitude of phases. Fig. 5b The first phase 521 is defined such that it comprises the deflection movement in which the heading angle 506 increases. The second phase 522 is defined such that it comprises the return steering movement in which the heading angle 506 decreases again. Alternatively or additionally, phases 521 and 522 can be defined such that the steering angle 502 or the steering acceleration in the first phase 521 has a first sign (relative to the initial position before initiating the evasive maneuver), and that the steering angle 502 or the steering acceleration in the second phase 522 has a second sign (relative to the initial position before initiating the evasive maneuver), with the first and second signs being opposite.

[0092] The control unit 201 can be configured to intervene in the steering during the first phase 521 in a manner greater than in the second phase 522. In other words, the evasive steering assistance can be applied with a higher intensity during the first phase 521 than in the second phase 522. Specifically, the steering assistance unit 206 can apply maximum steering assistance during the first phase 521. Reduced steering assistance can then be applied during the second phase 522. This is exemplified in Fig. 5b shown. Fig. Figure 5b shows the progression 505 of the steering assistance intensity 501 as a function of time 401 and as a function of the vehicle's distance traveled 101. With temporal control, the planned lateral acceleration is typically maintained, and with spatial control, the planned position is maintained (i.e., controlled), even if the vehicle's actual longitudinal speed deviates from the planned longitudinal speed. After activation of the evasive steering assist at time 405, the steering assistance is applied at maximum intensity 501 in the first phase 521. From the transition to the second phase 522, the steering assistance intensity is then continuously reduced.

[0093] Modulating the intensity of the steering assistance (505) allows for maximum support of the evasive maneuver in the critical initial phase while simultaneously providing a smooth handover to the driver.

[0094] Fig. Figure 5b shows a further third phase 523 of an evasive maneuver. In the third phase 523, a pause can be introduced. In particular, the activation of the evasive steering assist can be prevented in the third phase 523. This can be advantageous to calm the vehicle 101.

[0095] The steering assistance provided by the steering support unit 206 can include an additional steering torque, an additional steering angle and / or additional yaw moments from vehicle dynamics actuators (such as brakes, front-wheel drive / rear-wheel drive steering, roll stabilization, etc.).

[0096] As explained above, the first phase 521 can comprise a deflection movement and the second phase 522 a return movement. The deflection movement and return movement can refer to the target steering movement for the specified evasive trajectory 112.

[0097] As explained above, the evasive steering assist is designed to support the driver in keeping the vehicle 101 as close as possible to the specified evasive steering trajectory 112. The assist typically operates depending on the deviation of the actual trajectory 512 from the specified evasive steering trajectory 112. If the driver does not steer sufficiently in the direction of the evasive steering trajectory 112, the steering maneuver is amplified by the evasive steering assist. If the driver steers away from the evasive steering trajectory 112, the steering maneuver is dampened by the evasive steering assist. The control unit 201 selects the evasive steering trajectory from a multitude of determined evasive steering trajectories 111, 112 that corresponds to the driver's steering input.

[0098] As explained above, the control unit 201 is configured to determine one or more evasive trajectories 111, 112. An evasive trajectory 112 determined should offer the driver the greatest possible safety. Furthermore, the evasive trajectory 112 should correspond to a trajectory that the driver would typically and / or prefer to drive. This ensures that the actual trajectory 512 driven by the driver corresponds relatively closely to the previously determined evasive trajectory 112.

[0099] An evasive trajectory 112 around an obstacle 102 requires more lateral acceleration the less space is available next to the obstacle 102, i.e., the closer the vehicle 101 has to pass the obstacle 102, i.e., the sooner the driver has to steer back. The lateral acceleration can therefore tend to be reduced by having the vehicle 101 traverse the obstacle 102 with the largest possible lateral distance (also called arc distance). On the other hand, it should be noted that a late "steer back" (i.e., a reversal of lateral acceleration), e.g., only after passing the obstacle 102, does not further reduce the lateral acceleration but only increases the space required next to the obstacle 102. It is therefore also not advantageous to have the vehicle 101 traverse the obstacle 102 with too large a distance. This document therefore proposes determining an evasive trajectory 112 in such a way (e.g.,The endpoint of the evasive trajectory 112 is to be determined such that, if there is little space next to the obstacle 102, the available space is fully utilized (to reduce the lateral acceleration). On the other hand, if there is relatively ample space next to the obstacle 102, the evasive trajectory 112 can be planned with a predefined maximum distance to the obstacle 102, since a distance exceeding the maximum distance would not lead to a significant reduction in the lateral acceleration. A continuous transition between these two scenarios is possible. The distance 531 to the obstacle 102 used to determine the evasive trajectory 112 is given in . Fig. Figure 5a is shown schematically. This lateral distance 531 typically represents a target distance that is achieved when the vehicle 101 is parallel to the obstacle 102. Furthermore, a safety distance can be taken into account, which the vehicle 101 must maintain when passing the obstacle 102 along trajectory 112. The safety distance is shown in Fig. 5a is represented by the reference symbol 532.

[0100] In other words, the distance 531 to an obstacle, which is used to determine an evasive trajectory, can correspond to the available distance as long as the available distance is less than the predefined maximum distance. Once the available distance exceeds the predefined maximum distance, the distance 531 can be set to the maximum distance. This is in Fig. 6 are shown as examples. Fig. Figure 6 shows the distance 531 for determining an alternative trajectory 112 depending on the available distance 601. The predefined maximum distance 602 is also shown. Fig. Figure 6 shows, in dotted form, an alternative path for the distance 531 for determining an evasive trajectory 112. In this case, the distance 531 is chosen to be smaller than the available distance in a transition zone, even for available distances that are smaller than the predefined maximum distance 602. The dotted line better simulates typical driver behavior, as the driver typically weights the available space against the required lateral acceleration of the trajectory to account for measurement uncertainties and uncertain road friction coefficients.

[0101] The maximum distance 602 can be a fixed value with respect to the obstacle 102 (e.g., a fixed lane width). Alternatively, the maximum distance 602 can be a fixed value with respect to the vehicle 101 (e.g., a fixed width of an adjacent lane). The maximum distance 602 can also depend on how far (laterally) the obstacle 102 must be traversed. Furthermore, the selected distance 531 can depend on the criticality and / or the required lateral acceleration of the evasive maneuver.

[0102] The above-described choice of distance 531 for determining an evasive trajectory 112 results in an evasive trajectory 112 that would typically be desired by a driver. This allows for the greatest possible overlap between the actually driven trajectory 512 and the determined evasive trajectory 112.

[0103] An evasive maneuver can be supported by further measures to guide vehicle 101 past obstacle 102 as stably and safely as possible. In particular, a vehicle controller (e.g., a vehicle dynamics controller such as an Electronic Stability System) can be switched to a stabilizing mode (possibly with maximum strength). This stabilizing mode is typically not a restricted mode. The stabilizing vehicle controller mode can be activated immediately upon detection of a critical situation, i.e., even before the start of an evasive maneuver. Additionally, comfort functions of vehicle 101 can be deactivated at the start of the evasive maneuver. In situations without a concrete evasive option (sufficient space and the maneuver is feasible), activation of a stabilizing mode can only occur once the start of the evasive maneuver has been reliably detected.

[0104] Alternatively or additionally, automatic braking interventions and / or other active safety functions can be deactivated, canceled, or reduced when an evasive maneuver begins. Such automatic braking interventions and / or other active safety functions can be deactivated, canceled, or reduced, in particular, if the driver's initiation of an evasive maneuver has been confirmed by a second indicator. This ensures that such functions remain available for as long as possible. Safety functions can include, for example, a collision warning with brake intervention or cyclist / pedestrian protection systems.

[0105] As described above, the control unit 201 is configured to determine an evasive trajectory 112 upon detection of an obstacle 102. Specifically, upon detection of the driver's steering input, an evasive trajectory 112 can be calculated based on the available maneuvering space around the obstacle 102. Furthermore, the driver can be assisted in actually following the evasive trajectory 112. The evasive trajectory can be adapted to the expected surroundings and the planned longitudinal acceleration of the vehicle 101 (e.g., without braking). As previously stated, environmental perception can be achieved using environmental sensors 202 (e.g., radar and / or a video camera or comparable sensors).

[0106] The evasive trajectory 112 is calculated such that the vehicle 101 is guided around the obstacle 102 at a specific distance 531. For this purpose, the point of avoidance, i.e., the expected collision point without evasive action, can be predicted. For this, for example, an unchanged (possibly constant) movement of the obstacle 102 and an unbraked movement of the vehicle 101 can be assumed. The predicted point of avoidance can be updated during the approach based on environmental data. The safety distance 532 and / or the lateral distance 531 to the obstacle 102 can be fixed when determining the evasive trajectory 112 (e.g., by considering a constant lateral position of the obstacle 102 with respect to the vehicle 101's lane), and / or include the object prediction, and / or depend on the prediction uncertainty. For example, the distance 531 can be increased if the prediction uncertainty increases.Furthermore, the safety distance 532 can take into account the vehicle width and / or the control quality of the evasive steering assist.

[0107] The evasive maneuvering area next to the obstacle 102 typically needs to have a minimum width to allow for the determination of an evasive trajectory 112. This maneuvering area can take into account the lanes of vehicle 101. Furthermore, the maneuvering area should have a specific safety distance from the detected road edge 106 or from other vehicles. This specific safety distance can be fixed, incorporate object prediction, or depend on the prediction uncertainty.

[0108] Evasive steering assistance can be deactivated if the evasive lane is occupied or too narrow. Alternatively or additionally, evasive steering assistance can be deactivated if another obstacle (e.g., a pedestrian or another vehicle) is expected in the evasive lane, or if there are vehicles approaching from the side or overtaking from behind.

[0109] Furthermore, an evasive steering assist can be deactivated if the vehicle is driving with relatively high dynamics and / or if the determined evasive steering trajectory 112 is not safely drivable on the currently detected coefficient of friction.

[0110] An evasive steering assist system can be deactivated if the driver aborts the steering maneuver, exceeds the vehicle dynamics limit (e.g., through excessive steering), accelerates sharply, and / or brakes sharply.

[0111] By taking a predicted detour point into account, the most realistic possible evasive trajectory 112 can be determined. Furthermore, the aforementioned measures ensure that an evasive assistance system following the determined evasive trajectory 112 is interrupted if there are indications that the predicted detour point is no longer correct. This increases the safety of the evasive assistance system.

[0112] The evasive maneuver support, i.e., in particular an additional steering torque applied via the support unit 206, can be made dependent on the vehicle dynamics of the vehicle 101. The evasive maneuver support is intended to assist the driver of the vehicle 101 in controlling the vehicle. In other words, the evasive maneuver support is intended to assist the driver in controlling the system pathway, which consists of the steering, the vehicle, and the vehicle movement.

[0113] Fig. Figure 7a presents exemplary state variables of a vehicle 101, which can be used to describe the driving dynamics of a vehicle 101 during an evasive maneuver. A steering input or steering angle 701 typically causes a lateral acceleration 702 of the vehicle 101. The relationship between lateral acceleration 702 and steering angle 701 can be described, for example, by a vehicle model (e.g., a single-track model) 711 of the vehicle 101. Integrating 712 of the lateral acceleration 702 yields a heading angle (or lateral velocity) 703 of the vehicle 101, and integrating 713 of the heading angle (or lateral velocity) 703 yields a displacement 704 or a lateral offset of the vehicle 101 (relative to an initial position).

[0114] This document proposes considering one or more of the aforementioned state variables, and in particular the steering angle 701, when determining / controlling the steering torque to be applied (i.e., the additional torque caused by the assistance). This allows the steering torque to be determined precisely and with reduced phase delay. Specifically, a deviation of the vehicle 101 from the determined evasive trajectory 112 can be determined based on state variables such as delta lateral drift, delta lateral velocity or heading angle, lateral acceleration or curvature deviation, and / or deviation of the steering angle from the required steering angle. The deviation of the vehicle 101 from the determined evasive trajectory 112 thus determined can then be used to determine the steering torque to be applied.

[0115] Fig. Figure 7b shows an exemplary control loop that can be used to determine the steering torque to be applied by the steering assistance unit 206. The actual state variables 741, 742, 743, 744 can be detected using the sensors 205, 762, 763, 764. In particular, the steering sensor 205 can detect the actual steering angle 741, the yaw sensor 762 can detect the actual lateral acceleration 762, the speed sensor 763 can detect the actual heading angle (or actual lateral velocity) 743, and the position sensor 764 can detect the actual lateral deviation. One or more of the actual state variables 741, 742, 743, 744 can also be calculated using one or more measured actual state variables 741, 742, 743, 744 (e.g., according to the model from Fig. 7a).

[0116] On the other hand, a target position 724 can be determined from the determined evasive trajectory 112, a target heading angle (or target lateral speed) 723 can be derived by derivation 733, a target lateral acceleration 722 can be derived by derivation 732, and a target steering angle 721 can be determined by an inverted single-track model 731. Delta values ​​or deviations can then be determined from the respective target and actual state variables. The respective deviations can be summed in a summation unit 751 to determine a deviation of the vehicle 101 from the determined evasive trajectory 112. From this deviation, a control signal for the steering assistance unit 206 can then be determined in the control unit 752. In particular, it can be determined which steering torque (i.e., which additional torque) is to be applied by the steering assistance unit 206. Thus, driver support can be provided according to a (possibly weighted) sum of the deviations of the individual state variables.Significant deviations may lead to a termination of support.

[0117] As explained above, the target lateral velocity (i.e., the target heading angle) and the target lateral acceleration can be determined by deriving the target lateral displacement of the calculated evasive trajectory 112. The required target steering angle 721 for the evasive trajectory can be calculated from the target lateral acceleration 722 using the steady-state single-track model. In particular, the required target steering angle 721 for the evasive trajectory 112 can be calculated from the target lateral acceleration 722 using the inverted single-track model (e.g., second order) to take into account the vehicle's dynamic behavior. The required target steering angle for the evasive trajectory 112 can, if necessary, be used several time steps in advance to compensate for the phase caused by the steering of the vehicle 101 (or by the driver).

[0118] The current target lateral values ​​724, 723, 722, 721 of the evasive trajectory can be determined depending on the distance traveled (e.g., using odometry). If the environmental sensor 202 does not provide reliable values, the current actual lateral values ​​can also be determined from odometry (i.e., from the inertial vehicle sensors, compared with available environmental data).

[0119] Taking into account the various state variables when determining the degree of support for an evasive maneuver makes it possible to precisely adjust the degree of support to the deviation of the actual trajectory 512 from the determined evasive trajectory 112. This ensures that the driver is more likely to steer the vehicle 101 along the determined evasive trajectory 112.

[0120] As already explained above, the evasive trajectory 112 is preferably determined as smoothly as possible and with low lateral acceleration. Furthermore, the determined evasive trajectory 112 is preferably designed such that no steering angle oscillations are required to implement it. Additionally, the evasive trajectory 112 is preferably determined such that the vehicle 101 is stable at the end of the evasive maneuver (e.g., with constant lateral acceleration and constant steering angle).

[0121] The additional steering torque applied by the evasive steering assist can be configured such that the steering angle (and the required lateral acceleration) required for the compensating trajectory 112 is built up more quickly (than without assistance), and that when the steering torque is subsequently reduced, the driver is prompted to steer back quickly. Comparable vehicle dynamics interventions can also be used instead of steering torque. The steering torque curve can follow a scaled standard curve (e.g., trapezoidal). Alternatively, the curve can be linearly dependent on the assistance requirement. Instead of the reinforcing steering torque, a (typically small) counter-torque can also be provided, if necessary.

[0122] The steering torque curve can be adapted to the required assistance (i.e., the driver's action in relation to the available maneuvering space around obstacle 102). The required assistance can be determined by comparing the actual steering angle with a required target steering angle for a dynamic evasive trajectory. The required target steering angle for a dynamic evasive trajectory can be determined by considering the dynamic vehicle behavior (e.g., by an inverted single-track model 731).

[0123] The control unit 201 can be configured to detect excessively sharp steering inputs from the driver. In response, an additional damping steering torque can be applied, thus assisting the driver in not introducing excessive dynamics into the vehicle 101.

[0124] The above measures can be particularly useful during critical evasive maneuvers.

[0125] Typically, the evasive steering assistance operates subtly, so the driver is neither distracted nor disturbed by it. Furthermore, the assistance is typically not automatic or highly automated (but only in response to steering input from the driver). If the driver is following the predetermined evasive trajectory 112, no intervention typically occurs. Interventions typically only occur when the vehicle deviates from the predetermined evasive trajectory 112. The actual steering torque is largely applied by the driver (pre-controlled). The evasive steering assistance system primarily supports the driver in adjusting the evasive trajectory.

[0126] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and the figures are intended only to illustrate the principle of the proposed methods, devices, and systems.

Claims

[1] Control unit (201) for a vehicle (101), wherein the control unit (201) is configured, - to detect an obstacle (102) on a current trajectory of the vehicle (101); - to determine an available distance (601) next to the obstacle (102) for an evasive trajectory (111, 112); - to determine an evasive trajectory (111, 112) for the vehicle (101) with a target distance (531) next to the obstacle (102); wherein the target distance (531) -for available distances (601) smaller than a predefined maximum distance (602), except for a transition range corresponding to the available distance (601); - for available distances (601) greater than the predefined maximum distance (602), which corresponds to the maximum distance (602); and - in the transition range from an available distance (601) that is smaller than the predefined maximum distance (602) to an available distance (601) that corresponds to the maximum distance (602) that is smaller than the available distance (601); - to determine an indication that a driver of vehicle (101) initiated an evasive maneuver; and - depending on the evidence obtained and depending on the evasive trajectory obtained (111, 112), to initiate support for the evasive maneuver. [2] Control unit (201) according to claim 1, wherein the maximum distance (602) depends on one or more properties of the vehicle (101). [3] Control unit (201) according to a preceding claim, wherein the maximum distance (602) depends on a lateral acceleration of the vehicle (101) on the determined avoidance trajectory (111, 112). [4] Control unit (201) according to a preceding claim, wherein the support of the evasive maneuver comprises acting on a steering device (203) of the vehicle (101) and / or performing a vehicle dynamics intervention with yaw reaction of the vehicle (101), depending on the determined evasive trajectory (111, 112). [5] Control unit (201) according to a preceding claim, wherein the evasive maneuver support comprises one or more of: - Adapting a vehicle controller to increase vehicle stability (101); and / or - Preventing, canceling and / or reducing automatic brake intervention. [6] Control unit (201) according to a preceding claim, wherein the control unit is configured, - to predict a changing position of the obstacle (102); and - to determine the evasive trajectory (111, 112) depending on the predicted position of the obstacle (102) and / or taking into account a safety distance (532) to the predicted position of the obstacle (102). [7] Control unit (201) according to a preceding claim, wherein the available distance (601) next to the obstacle (102) depends on one or more of: - a roadside or the edge of a roadway; - a predicted position of one or more other road users; and / or - a safe distance to the predicted position of one or more other road users or to the edge of the road. [8] Control unit (201) according to a preceding claim, wherein the control unit is configured to prevent assistance of the evasive maneuver when - the available distance (601) is less than or equal to a predefined minimum distance; and / or - another obstacle is detected or predicted on the determined evasive trajectory (111, 112) and / or - the determined evasive trajectory (111, 112) is not drivable with a determined coefficient of friction of the vehicle (101) on a roadway. [9] Method (300) to assist a driver of a vehicle (101) in an evasive maneuver, wherein the method (300) comprises, - Detecting (301) an obstacle (102) on a current trajectory of the vehicle (101); - Determine (302) an available distance (601) next to the obstacle (102) for an evasive trajectory (111, 112); - Determining (302) the evasive trajectory (111, 112) for the vehicle (101) with a target distance (531) next to the obstacle (102); wherein the target distance (531) -for available distances (601) smaller than a predefined maximum distance (602), except for a transition range corresponding to the available distance (601); - for available distances (601) greater than the predefined maximum distance (602), which corresponds to the maximum distance (602); and - in the transition range from an available distance (601) that is smaller than the predefined maximum distance (602) to an available distance (601) that corresponds to the maximum distance (602) that is smaller than the available distance (601); - Determining (303) an index of the initiation of an evasive maneuver by the driver of the vehicle (101); and - depending on the evidence obtained and depending on the evasive trajectory obtained (111, 112), carrying out (304) support of the evasive maneuver.

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