Methods for assisting the driver of a motor vehicle during a parking maneuver

Abstract

Methods for assisting the driver of a motor vehicle during a parking maneuver in parallel parking spaces, comprising the following steps: a) sensory measurement of a found parking space, b) Decision based on the survey data determined in step a) and on the vehicle data as to whether the parking space is suitable for the vehicle to park, c) Calculation of a parking lane using a lane planning algorithm, d) Start of a parking maneuver taking into account the parking target path, e) Checking the vehicle's yaw angle when the parking train stops, f) Termination of the parking maneuver if the yaw angle is less than a predetermined limit, g) Starting another parking maneuver in a predetermined direction of travel (forward or backward) with maximum steering angle to the right or left if the yaw angle is greater than the predetermined limit, h) rechecking the yaw angle when the next parking maneuver stops, i) Termination of the parking maneuver when the yaw angle is less than the specified limit, j) Starting another parking maneuver if the yaw angle is greater than the specified limit, wherein the direction of travel (forward or backward) and the direction (right or left) of the maximum steering angle in this parking maneuver are opposite to the parking maneuver in step g), k) rechecking the yaw angle when the next parking maneuver stops, I) Termination of the parking maneuver when the yaw angle is less than the specified limit, m) Repeat the steps from g) if the yaw angle is greater than the specified limit, characterized by the further step: n) that when a parking train stops, a signal is generated, whereupon the yaw angle check and the further steps are initiated.

Description

[0001] The invention relates to a method for assisting the driver of a motor vehicle during a parallel parking maneuver. Such a method is known, for example, from DE 10 2004 001 428 A1. First, a parking space is measured with regard to its characteristic data (length, width) using sensors mounted on the vehicle (e.g., an ultrasonic distance sensor). Then, in a next step, a decision is made based on the determined parking space data and vehicle data as to whether the parking space is suitable for the vehicle. Subsequently, a single-pass parking path is calculated using a path planning algorithm. Single-pass means that the path must be traversed without changing direction (forward / backward).

[0002] There are so-called parking assistance systems in which the steering is performed completely autonomously during the parking process via a steering actuator, guiding the vehicle along the intended parking path. The driver can only set the speed and brake / stop. However, there are also parking assistance systems in which the driver is only provided with acoustic, visual, or haptic parking support information to guide the vehicle along the intended parking path, with the driver still making the steering adjustments based on this information.

[0003] The following problems can occur with such parking assistance systems: a) Even when parking with a parking assistance system, the driver naturally has the option to stop the vehicle at any time during the parking maneuver for safety reasons. Drivers' behavior in this regard varies considerably. In particular, overly cautious drivers tend to stop the vehicle too early due to an obstacle bordering the parking space (e.g., a parked vehicle). However, stopping the vehicle too early during the parking maneuver results in the vehicle being parked at an angle in the parallel parking space. b) If the driving speed during the parking maneuver is too high, the limited speed of the steering actuator may cause an uncorrectable deviation from the intended parking path, resulting in the vehicle being parked at an angle and too low in the parking space. c) An incorrect or inaccurate measurement of the parking space may force the driver to stop the vehicle before reaching the final position of the parking lane. In this case, too, the vehicle will be parked at an angle in the space.

[0004] For example, EP 1 160 146 B1 discloses a parking aid device for assisting a driver during a parking operation of a vehicle, wherein the parking operation comprises a first step in which the vehicle is moved in one direction by turning a steering device, and a second step in which the vehicle is moved in the opposite direction to that of the first step by turning the steering device.The parking aid device further comprises a display device arranged in a passenger compartment, wherein the display device displays, firstly, an image captured by a camera in a direction in which the vehicle is moving, and secondly, steering information to inform the driver of a time at which the steering device must be turned in the opposite direction in conjunction with the assumed path, and wherein the display device displays the steering information by superimposing the steering information on the image captured by the camera.

[0005] Furthermore, DE 103 54 661 A1 discloses a device for semi-automatic support of the parking process for vehicles, comprising a device for determining the size of a parking space, a computing unit, means for recording the current position of the vehicle, and a communication device with which information and / or instructions about a parking process can be indirectly transmitted to a vehicle driver, wherein the computing unit is designed to re-determine the orientation of the vehicle in relation to the parking space and the maneuvering distance in front of and behind the vehicle after the vehicle has entered the parking space based on a predetermined parking path, and to recalculate at least one further parking path based on this data.

[0006] The object of the invention is to create a method for assisting the driver during a parking maneuver with a parking assistance system, which also makes it possible to achieve a perfect parking position in a simple manner when one of the above-mentioned problems occurs.

[0007] This problem is solved by the features of claim 1.

[0008] According to the invention, when the first parking maneuver is stopped / aborted, which is carried out taking into account the calculated parking path, the position, in particular the orientation, of the vehicle in the parking space is checked. If it is determined that the vehicle is parked at an angle in the parking space, no elaborate attempt is made to guide the vehicle in single or multi-stage maneuvering using a newly calculated parking path. According to the invention, the next parking maneuver is carried out with maximum steering angle, the direction (right or left) of which depends on the selected direction of travel (forward or reverse).

[0009] The yaw angle of the vehicle is particularly suitable for checking its alignment when stopping or aborting a parking maneuver. The yaw angle is defined as the angle between the vehicle's longitudinal axis and the longitudinal direction of the parking space. This yaw angle is determined using data from the parking space, the distance traveled, the corresponding steering angle signals, and model-based vehicle data.

[0010] The method according to the invention is more tolerant of a stop / abort of the parking maneuver according to the calculated parking path. Should a further parking maneuver be necessary as a corrective maneuver after a stop / abort of a parking maneuver, this is always transparent and comprehensible for the driver, since it is always started with maximum steering lock. In this way, driver confusion is avoided and confidence in the parking assistance system is increased.

[0011] The driver can individually stop a parking maneuver according to their driving behavior, without the vehicle remaining at an angle in the parking space without any further support, and without potentially irritating further parking maneuvers according to a newly calculated parking path, for which they might first have to drive to a new starting position.

[0012] The invention is explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 the initial situation after finding the parking space, Fig. 2 a vehicle standing at an angle in the parking space after a parking train has stopped, Fig. 3 a flowchart of the method according to the invention.

[0013] Fig. Figure 1 represents the initial situation after the parking space has been located. In the illustrated case, the parking space (P) is bordered by two parked vehicles (1, 2). To measure the parking space (in particular its width B and length L), the vehicle to be parked (3) has at least one lateral distance sensor (3A), in particular an ultrasonic sensor.

[0014] After the parking space (P) has been measured, a control unit of the parking assistance system implemented in the vehicle decides whether the parking space (P) is suitable for the vehicle (3) to park in. For this purpose, the data (B, L) of the parking space (P) and the data of the vehicle are used. If the parking space (P) is suitable, a parking path (SB) is calculated using a path planning algorithm, which is then displayed in Fig. 1 is shown schematically. Subsequently, a first parking maneuver is started, taking into account the calculated target parking path (SB).

[0015] If this parking maneuver is stopped or aborted for any reason, the vehicle's yaw angle is checked according to the invention. Ideally, the yaw angle is zero degrees at the end of the parking maneuver. Then the vehicle is straight, i.e., aligned lengthwise with the parking space (P) and, for example, parallel to the curb (5). However, a yaw angle other than zero means that the vehicle is not aligned lengthwise with the parking space, but at an angle to it. The yaw angle check determines whether the yaw angle is less than a predefined limit. This limit can be close to zero degrees.

[0016] If the check shows that the yaw angle is smaller than the limit value, the parking maneuver is successfully completed. Otherwise, according to the invention, a further parking maneuver is initiated. This further parking maneuver (corrective maneuver) is now performed with maximum steering angle, the direction (right or left) of the steering angle depending on the direction of travel (forward or reverse) for this parking maneuver. In the illustrated example, the first parking maneuver, which is carried out taking the intended parking path into account, is performed while reversing. After the stop / abort of this first parking maneuver, the next maneuver is performed with the vehicle tilted (see Fig. 2) The vehicle's correction maneuver is performed at maximum right steering angle and while driving forward. If this correction maneuver is aborted, a second correction maneuver would be performed – if necessary – at maximum left steering angle and while driving in reverse. This procedure can be continued iteratively if necessary.

[0017] When a parking maneuver is stopped or aborted, the vehicle is brought to a halt, generating a signal that triggers a yaw angle check and, if necessary, the initiation of a correction maneuver. This signal can be generated automatically when the gear selector is engaged, i.e., whenever the driver shifts into neutral or changes direction (reverse to forward or vice versa) while stopping or aborting a parking maneuver. Alternatively or additionally, the signal can also be generated by distance sensors (not shown) located at the front and / or rear of the vehicle, which measure the distance to obstacles in front or behind.

[0018] In Fig. 3 The inventive method is illustrated in a flowchart.

Claims

[1] Method for assisting the driver of a motor vehicle in a parking maneuver in parallel parking spaces comprising the following steps: a) sensory measurement of a found parking space, b) Decision based on the survey data determined in step a) and on the vehicle data as to whether the parking space is suitable for the vehicle to park, c) Calculation of a parking lane using a lane planning algorithm, d) Start of a parking maneuver taking into account the parking target path, e) Checking the vehicle's yaw angle when the parking train stops, f) Termination of the parking maneuver if the yaw angle is less than a predetermined limit, g) Starting another parking maneuver in a predetermined direction of travel (forward or backward) with maximum steering angle to the right or left if the yaw angle is greater than the predetermined limit, h) rechecking the yaw angle when the next parking maneuver stops, i) Termination of the parking maneuver when the yaw angle is less than the specified limit, j) Starting another parking maneuver if the yaw angle is greater than the specified limit, wherein the direction of travel (forward or backward) and the direction (right or left) of the maximum steering angle in this parking maneuver are opposite to the parking maneuver in step g), k) rechecking the yaw angle when the next parking maneuver stops, I) Termination of the parking maneuver when the yaw angle is less than the specified limit, m) Repeat steps from g) if the yaw angle is greater than the specified limit, characterized by the next step: n) that when a parking train stops, a signal is generated, whereupon the yaw angle check and the further steps are initiated. [2] Method according to claim 1, characterized by , that the signal is generated when the gearshift is activated. [3] Method according to claim 1, characterized by that the signal is generated via distance sensors. [4] Method according to any of the preceding claims, characterized by , that the steering angle is reduced to zero after the start of a parking maneuver according to steps g) or j) starting from the maximum steering angle during the course of the parking maneuver.

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