Method and device for transferring a motor vehicle from a manual operating mode to an automated or assisted operating mode

Abstract

Method for transferring a motor vehicle (1) from a manual operating mode to an automated or assisted operating mode for following a trained and stored trajectory (2), wherein a tolerance range (3) is stored for the trained and stored trajectory (2), wherein, upon fulfillment of at least one predetermined criterion, a transition trajectory (4) from a current actual position to the trained and stored trajectory (2) is calculated and a steering torque is generated that steers the motor vehicle in the direction of the calculated transition trajectory (4), wherein the at least one criterion is a distance threshold to the trained and stored trajectory (2), wherein the distance threshold is chosen such that it lies outside the tolerance range (3).

Description

[0001] The invention relates to a method and a device for converting a motor vehicle from a manual operating mode to an automated or assisted operating mode.

[0002] For example, with the "Trained Parking" function, a driver can teach the vehicle a trajectory to a parking space, which is then stored in the vehicle. On subsequent trips, the vehicle can then automatically follow this trajectory. For localization within the driving environment, environmental sensors (e.g., a front camera) capture features and store them in a digital localization map. To initiate automated departure, the driver drives close to the stored trajectory. The vehicle locates itself, and the driver can then transfer control of the driving task to the vehicle. The trained parking space can be selected in the navigation system before starting the journey. For safety reasons, the area within which the trained trajectory can be automatically followed is limited. This limitation defines a tolerance range within which the vehicle must be located for automated driving to be possible.Furthermore, the possible lateral distance and angular orientation of the vehicle relative to the trajectory, within which the vehicle can still be located on the digital map, are limited by the sensor technology used. This is particularly true when using a front camera.

[0003] As previously explained, the driver must guide the vehicle within the tolerance zone around the trajectory so that it can be followed automatically. The driver may sometimes only know the exact location and, in particular, the starting point of the trajectory, or may even be completely unaware of it. Reasons for this can include: - It's been a while since I practiced the trajectory to a parking space, - the trajectory training was performed by another person or technical equipment, - the training was performed automatically by the vehicle, - the starting point of the trajectory is not explicitly trained (e.g., if a fixed distance is always trained starting from the parking lot).

[0004] A possible visualization of the trajectory on a display unit distracts the driver's attention and could be perceived as disruptive by a skilled driver who knows where their trained trajectory begins.

[0005] From DE 10 2013 201 799 A1, a driver assistance system for a vehicle is known, comprising at least one sensor for generating a vehicle status signal and / or environmental signal, and a processing unit that records a route based on the vehicle status signal and / or environmental signal. The processing unit is further configured to recognize a specific position of the vehicle by comparing the recorded route with a stored route and to offer a stored trajectory to the driver when the specific position is recognized, wherein the driver assistance system is configured to control the vehicle to drive the trajectory autonomously or semi-autonomously.

[0006] German patent DE 10 2010 031 672 A1 discloses a method for assisting a vehicle driver during a driving maneuver, in which the vehicle is automatically guided along a previously calculated trajectory or the lateral guidance for driving along the trajectory is automatically performed, and control is handed back to the driver after completion of the driving maneuver. Information about the vehicle's surroundings and suitable steering settings is provided to the driver before and / or during the handover of control.

[0007] From DE 10 2013 017 212 A1 a method for controlling a motor vehicle is known, comprising at least one driver assistance system, wherein the motor vehicle is controllable by a driver in a first operating mode of the driver assistance system, comprising the steps: - Collection of ego data relating to the vehicle and / or environmental data relating to the vehicle's surroundings, - Determine whether the motor vehicle has left a lane or will leave the lane in the future with a probability exceeding a predetermined minimum probability by evaluating the ego data and / or the environmental data by the driver assistance system, and in this case - temporary switching of the driver assistance system to the second operating mode, - autonomous steering of the motor vehicle without the possibility of intervention by the driver through the driver assistance system in the second operating mode.

[0008] The invention addresses the technical problem of providing a method for converting a motor vehicle from a manual operating mode to an automated or assisted operating mode for following a stored trajectory. A further technical problem is the creation of a suitable device.

[0009] The solution to the technical problem is achieved by a method having the features of claim 1 and a device having the features of claim 8. Further preferred embodiments are described in the dependent claims.

[0010] The method for transitioning a motor vehicle from a manual operating mode to an automated or assisted operating mode for following a stored trajectory, wherein a tolerance range is stored for the stored trajectory, includes the process step that, upon fulfillment of at least one predefined criterion, a transition trajectory from the current actual position to the stored trajectory is calculated and a steering torque is generated that steers the motor vehicle in the direction of the calculated transition trajectory. The at least one criterion is a distance threshold to the stored trajectory, the distance threshold being selected such that it lies outside the tolerance range. Thus, the driver is guided with assistance into the tolerance range, and from that point on, depending on the embodiment, the vehicle follows the trajectory either automatically or with assistance.During assisted departure, for example, only lateral guidance can be automated, or steering torques can be generated to make it more difficult to leave the tolerance range. The transition to automated departure upon reaching the tolerance range can occur either automatically or after confirmation by the driver. If the tolerance range is arranged symmetrically around the trajectory, the distance threshold must be at least half the tolerance range. However, the distance threshold should not be set too high, as this could lead to confusion due to the steering torque. A possible distance threshold is, for example, 20 m.

[0011] In one embodiment, when several trajectories are stored, the trajectory that best fulfills the criterion(s) or that was pre-selected is chosen. It may also be provided that, in the case of multiple criteria, these are weighted.

[0012] In another embodiment, the transition trajectory is calculated as a function of the vehicle speed and / or the lateral distance. At higher vehicle speeds or greater lateral distances, a longer transition trajectory is calculated in order to limit the magnitude of the steering torque.

[0013] In a further embodiment, longitudinal control is additionally adapted. For this purpose, for example, the setting speed of an ACC controller or a cruise control system is adjusted so that the subsequent automated driving along the trajectory by the parking controller or another controller for automated driving is safe and comfortable. If a stop is required by standards for the transition between assisted driving onto the trajectory and automated departure from the trajectory, this stop can also be performed automatically after reaching the stored trajectory.

[0014] In another embodiment, the calculated transition trajectory is dynamically adjusted for newly detected obstacles in order to take previously undetected obstacles into account.

[0015] In another embodiment, the procedure is aborted if the hand torque exceeds a threshold value contrary to the generated steering torque, i.e., the driver can abort the assisted approach to the trajectory at any time.

[0016] The device for transitioning a motor vehicle from a manual operating mode to an automated or assisted operating mode for following a stored trajectory comprises a memory in which the trajectory and a tolerance range of the trajectory are stored. The device further comprises means for localizing the motor vehicle relative to the stored trajectory and a control unit, wherein the control unit is configured such that, upon fulfillment of at least one predetermined criterion, a transition trajectory from a current actual position to the stored trajectory is calculated and a steering torque is generated that steers the motor vehicle in the direction of the calculated transition trajectory, wherein the at least one criterion is a distance threshold to the stored trajectory, the distance threshold being selected such that it lies outside the tolerance range.

[0017] Regarding further embodiments of the device, reference is made to the preceding explanations of the method.

[0018] The invention is explained in more detail below with reference to a preferred embodiment. The figures show: Fig. 1. An exemplary situation for assisted approach to a laid trajectory, Fig. 2 a schematic block diagram of a device for transferring a motor vehicle from a manual operating mode to an automated or assisted operating mode and Fig. 3 a schematic flowchart of a procedure for transferring a motor vehicle from a manual operating mode to an automated or assisted operating mode.

[0019] In the Fig. Figure 1 depicts a situation of a motor vehicle 1 operating in manual mode. The motor vehicle 1 is positioned at a lateral distance from a defined trajectory 2, with a tolerance zone 3 around the trajectory 2 being shown. A calculated trajectory 4 is also shown, by means of which the motor vehicle 1 can be guided into the tolerance zone 3, where the dashed line describes a trajectory to the defined trajectory 2. The size of the tolerance zone 3 is indicated by the double arrow.

[0020] The device 10 for transferring the motor vehicle 1 from a manual operating mode to an automated or assisted operating mode within tolerance range 3 is in Fig. Figure 2 shows the device 10. It comprises a memory 11 in which the trajectory 2 and the tolerance range 3 are stored. The device 10 further comprises means 12 for localizing the motor vehicle 1 relative to the at least one stored trajectory 2, and at least one control unit 13. The control unit 13 receives the data from the means 12 and can read the memory 11. The control unit 13 also receives further vehicle data, in particular the vehicle speed V. The control unit 13 can calculate a transition trajectory 4 to the tolerance range 3 and calculate control signals for a lateral controller 14 and a longitudinal controller 15.

[0021] The functionality of device 10 will now be explained using the following examples: Fig.3 will be explained. In a first step S1, the vehicle 1 locates itself relative to the stored trajectories 2 using means 12. Localization can be performed using GPS and / or landmarks. To activate the assisted transition from manual operating mode to automated operating mode, the following criteria are checked for the found trajectories 2 in step S2, whereby only the first criterion is mandatory: - the distance to the first or next trajectory point is less than a distance threshold, - the direction of travel of the vehicle matches the possible directions of travel of the trajectory, - the trajectory lies within the lane itself, - the lateral distance and the orientation to the trajectory are sufficiently small, i.e., the angle between the vehicle's longitudinal axis and the trajectory is considerably less than 90°.

[0022] In a subsequent step S3, it is checked whether several trajectories 2 meet the criteria. If so, step S4 determines which trajectory 2 best meets the criteria, or whether the driver has already made a manual pre-selection. If, however, only one trajectory 2 meets the criteria, it is used for further processing in step S5. In this step S5, the control unit 13 determines the nearest point on the selected trajectory 2 and the orientation of the trajectory 2 with respect to the vehicle's orientation. A transition trajectory 4 is calculated for this point, whereby the maximum curvature is influenced by the lateral distance to the trajectory and the vehicle speed. With a large lateral offset, the curvature decreases, and thus the length of the transition trajectory 4 increases.Accordingly, at higher speeds, the curvature is also reduced, and the transition trajectory 4 is correspondingly longer. The control unit 13 then generates a steering torque in the direction of the calculated transition trajectory 4, which the driver feels at the steering handle. If the driver does not override this steering torque, the vehicle is guided in the direction of trajectory 2. The longitudinal guidance can also be adjusted. In step S6, it is checked whether the tolerance range 3 has been reached. If this is not the case, the process continues. If, however, it is, in step S7 the system automatically switches to automated operating mode, either automatically or after manual activation, and the driver can, for example, take their hands off the steering handle, while the vehicle automatically follows the trajectory.

[0023] The process enables a smooth transition from manual to automated driving on trained or otherwise provided trajectories. It also improves automated trajectory navigation, as the vehicle can be optimally aligned with the trajectory during the initial approach. The function is easy to implement, as it operates similarly to a lane-assist system.

Claims

[1] Method for transferring a motor vehicle (1) from a manual operating mode to an automated or assisted operating mode for driving a trained and stored trajectory (2), wherein a tolerance range (3) is stored for the trained and stored trajectory (2), wherein, upon fulfillment of at least one predetermined criterion, a transition trajectory (4) from a current actual position to the trained and stored trajectory (2) is calculated and a steering torque is generated that steers the motor vehicle in the direction of the calculated transition trajectory (4), wherein the at least one criterion is a distance threshold to the trained and stored trajectory (2), wherein the distance threshold is chosen such that it lies outside the tolerance range (3). [2] Method according to claim 1, characterized by, that a further criterion for calculating a transition trajectory (4) is that the direction of travel of the motor vehicle (1) matches the possible directions of travel of the trained and stored trajectory (2) and / or the trained and stored trajectory (2) lies in a current lane and / or the lateral distance and orientation to the trained and stored trajectory (2) is sufficiently small. [3] Method according to claim 1 or 2, characterized by , that when several trajectories have been trained and stored (2), the trajectory chosen is the one that best meets the criterion(s) or that has been pre-selected. [4] Method according to any of the preceding claims, characterized by , that the calculation of the transition trajectory (4) is performed depending on the vehicle speed (V) and / or the lateral distance. [5] Method according to any of the preceding claims, characterized by, that a longitudinal control is also adjusted. [6] Method according to any of the preceding claims, characterized by , that the calculated transition trajectory (4) is dynamically adjusted when new obstacles are detected. [7] Method according to any of the preceding claims, characterized by , that if the hand torque exceeds a threshold value contrary to the generated steering torque, the procedure is aborted. [8] Device (10) for transferring a motor vehicle from a manual operating mode to an automated or assisted operating mode for driving a trained and stored trajectory (2), comprising a memory (11) in which the trained trajectory (2) and a tolerance range (3) of the trained trajectory (2) are stored, means (12) for localizing the motor vehicle (1) relative to the trained and stored trajectory (2) and a control unit (13), wherein the control unit (13) is configured such that, upon fulfillment of at least one predetermined criterion, a transition trajectory (4) from a current actual position to the trained and stored trajectory (2) is calculated and a steering torque is generated that steers the motor vehicle (1) in the direction of the calculated transition trajectory (4), wherein the at least one criterion is a distance threshold to the trained and stored trajectory (2),wherein the distance threshold is chosen such that it lies outside the tolerance range (3).

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