Method and device for safely parking a vehicle

Abstract

A method for safely parking a vehicle, wherein, upon completion of a parking maneuver, at least two wheels of the vehicle are automatically turned such that they point towards the edge of the roadway in the direction of travel, and wherein the automatic control includes an upper threshold value for the force with which the wheels are turned, characterized in that, during the parking maneuver, a distance to the edge of the roadway is continuously determined by means of a detection device, and that - the parking maneuver is a manual parking maneuver, with longitudinal and lateral control of the vehicle by the driver, and - automatic control does not occur if a minimum distance to the edge of the road is not maintained while the vehicle is in a parked position.

Description

[0001] The invention relates to a method for safely parking a vehicle according to the preamble of claim 1. The invention further relates to a device for implementing the method according to the invention.

[0002] A generic method is known from DE 10 2012 103 059 A1. This patent discloses a method for the safe parking of a vehicle, which includes means for detecting a road edge, means for automatically controlling a steering system, and means for detecting a parking situation. Within the framework of the method, upon detection of a parking situation, i.e., when it is recognized that the vehicle is in its final parking position, at least two wheels of the vehicle are automatically turned so that they point towards the edge of the road in the direction of travel. This ensures, particularly in parking situations on slopes, that if the vehicle rolls away, it will roll towards the edge and be stopped by it. The edge is, for example, the curb or kerbstone at the edge of the road.

[0003] DE 10 2010 001 922 A1 discloses a method for turning a steerable wheel of a motor vehicle when parked on a longitudinal incline, wherein the adjustment of the steering angle depends on the vehicle's surroundings as determined by a sensor. For this purpose, after the vehicle has been parked and its parking brake has been activated, the angle of inclination caused by the longitudinal incline of the road and the surroundings are determined. In determining the surroundings, the lateral distance of the vehicle from a curb is specifically recorded. Furthermore, when the wheel is turned, a measuring device detects the increase in the force required to adjust the steering angle to the desired position.For example, if the steerable wheel hits the curb before the steering angle is set, further adjustment of the steering angle will be interrupted based on the resulting increase in force.

[0004] From JP 2007-237 838 A, a method for turning the steerable wheels of a motor vehicle when parking the vehicle on a slope is known. To prevent the parked vehicle from rolling away unintentionally, the wheels are turned towards the edge of the roadway after the vehicle has been parked. After parking, it is first determined whether a wheel turned in this way or the vehicle body would come into contact with a lateral obstacle if the vehicle were to roll away. The wheels are only turned if a wheel would come into contact with the lateral obstacle first.

[0005] EP 1 642 767 A1 describes a method for providing parking assistance to a motor vehicle, wherein the dimensions of a parking space are determined by means of distance sensors arranged on the motor vehicle. When a boundary of the parking space is detected due to a change in the vehicle's driving resistance, the previously determined dimensions of the parking space are corrected.

[0006] DE 10 2008 012 912 A1 discloses a method for detecting when a motor vehicle touches a curb while parking or pulling out of a parking space. For this purpose, the current driving resistance of the motor vehicle is determined and, in conjunction with a driving resistance-independent plausibility check, a curb contact is inferred based on a change in the driving resistance.

[0007] The present invention is based on the recognized problem that the automatic turning of the wheels can lead to damage to the vehicle, especially if the distance to the road edge is too small, which can then result in damage to the wheels and the steering mechanism of the vehicle.

[0008] The object of the present invention is therefore to provide an improved method and an improved device for the safe parking of a vehicle.

[0009] This problem is solved by a method with the features of claim 1 and by a device with the features of claim 4. Advantageous embodiments of the invention are the subject of sub-claims.

[0010] A key aspect of the invention is that, during the automatic control of the wheels—that is, when they are turned towards the edge of the roadway at the end of a parking maneuver—an upper threshold is provided for the force with which the wheels are turned. The force with which the wheels are turned is preferably continuously monitored, and the upper threshold is preferably selected such that the wheels are turned safely without causing damage to the vehicle. In particular, the upper threshold is set such that the turning of the wheels is stopped as soon as the wheels touch a road edge.

[0011] The method according to the invention thus serves for safe parking, in particular for safely parking or leaving a vehicle, e.g., in a parking space or parking bay. Within the framework of the method, it is provided that, upon completion of a parking maneuver, i.e., upon reaching a final parking position, at least two wheels of the vehicle are automatically turned so that they point towards the edge of the roadway in the direction of travel. Within the framework of the method according to the invention, an upper threshold value is provided for the force with which the wheels are turned during the automatic control of the wheels.

[0012] Preferably, the invention is implemented in a parking situation on a slope. Parking on a slope is preferably detected using a longitudinal acceleration sensor in combination with a standstill detection system. Standstill detection is preferably carried out with the aid of wheel rotation sensors. Longitudinal acceleration sensors are already used in vehicles, for example, in ESP or occupant protection systems (airbag activation after accident detection by an acceleration sensor). If the longitudinal acceleration sensor outputs a value above a defined threshold when the vehicle is stationary, it can be assumed that the vehicle is parked on an incline or slope.

[0013] In a preferred embodiment of the invention, a parking situation is recognized based on one or more of the following criteria: - A parking brake lever or switch is operated by the driver. In a preferred embodiment of the invention, a parking situation is recognized based on additional criteria, e.g., stopping for longer than a predetermined time t1 (threshold) and / or the driver unbuckling their seatbelt and / or opening the door. - The vehicle's electronic parking brake is activated, in particular by automatic activation.

[0014] In a preferred embodiment of the invention, a parking situation is recognized based on additional criteria, e.g. stopping for longer than a predetermined time t1 (threshold), when a standstill of the vehicle is detected and the driver unbuckles his seatbelt and / or opens the door and / or when a parking maneuver carried out by an automatic parking assistant has been completed.

[0015] It is also important to determine the direction in which the wheels should be turned. The following methods are preferably used for this purpose: - The edge fastening is detected via environmental sensors (e.g. camera, ultrasound, ...). - By analyzing a maneuver before the initiation of parking actuators such as the parking brake, the system determines the direction in which the edge of the vehicle should be positioned. For example, during a parking maneuver to the right in the direction of travel, it can be assumed that the edge of the vehicle is on the right. The parking maneuver here refers to the entire process, not just the final steering input in, for example, a multi-stage parking maneuver. Similarly, during a parking maneuver to the left in the direction of travel, it can be assumed that the edge of the vehicle is on the left. A parking maneuver is detected either by activating a parking assistant or by recording the direction in which the vehicle has moved within a predefined time period, which ranges from 5 to 90 seconds. In a preferred implementation, this time period is approximately 10 seconds.In a particular embodiment of the invention, this information is consulted during standstill detection. - The driver indicates the direction using the turn signal, which also activates the parking lights.

[0016] In the inventive method, during the automatic control of the wheels, the force with which the wheels are turned is preferably continuously determined, and the automatic control of the wheels is preferably terminated as soon as the force reaches the upper threshold.

[0017] The upper threshold for the force with which the wheels are turned is preferably set such that the automatic control is terminated as soon as at least one of the wheels touches a road edge fixing, for example the curb or kerbstone, or another obstacle when turning.

[0018] According to the invention, during the parking maneuver, a distance to the edge of the road is continuously determined by means of at least one detection device. The driver can, for example, be continuously provided with information about the current distance to the edge of the road, e.g., visually or audibly.

[0019] If the parking maneuver is a manual parking maneuver, i.e., a parking process with manual longitudinal and lateral control of the vehicle by the driver, then the method according to the invention provides that the automatic control of the wheels does not take place if, in a parking position, i.e., when the final parking position is reached, a minimum distance to the edge of the road is not maintained.

[0020] If the parking maneuver is an automated parking maneuver, i.e., a parking process with at least automated lateral control and optionally automated longitudinal control of the vehicle by a parking assistance system, then, in a non-inventive alternative of the method, it is provided that a minimum distance to the edge of the road is maintained during the automated parking maneuver. Maintaining the minimum distance refers in particular to maintaining the minimum distance when reaching the final parking position. During the parking maneuver, i.e., while maneuvering the vehicle into the final parking position, a reduction of the minimum distance may be permitted.

[0021] The device according to the invention comprises means for automatically controlling the steering of the vehicle and serves to implement the method according to the invention, in particular according to one of the embodiments described above. According to the invention, the device comprises at least one device for detecting the force with which the wheels are turned when the parking maneuver is completed.

[0022] For example, the following can be used as a means of recording the force, i.e., measuring the (adjustment) force with which the wheels are turned: a) a measurement of the current for the drive of an electric adjustment mechanism, or b) the pressure for the drive of the / a hydraulic adjustment mechanism, to be used.

[0023] In a preferred embodiment, the evaluation of the recorded parameters is carried out in such a way that a a) the typical current for driving the / an electric adjustment mechanism, or b) of the typical pressure for the drive of the hydraulic adjustment mechanism, a significantly increased / rising value is used as a criterion that the adjustment / wheel steering is acting upon an increased counterforce, the increased counterforce being caused by the contact of the corresponding wheel with the road edge fastening.

[0024] When this significantly increased (rising) value, which serves as a threshold (threshold gradient), is reached, the automatic control of the wheels is terminated as a reaction.

[0025] In another preferred embodiment, the threshold is implemented as a dynamic value, whereby the applicable threshold is determined as a difference from a current value or evaluated as a change in the gradient. Dynamic threshold adjustment / evaluation has the advantage, for example, that current road conditions (icy road, road with snow, etc.) can be better taken into account.

[0026] The device according to the invention further comprises at least one device for detecting the distance to the edge of the roadway. Various sensor systems known for vehicle environment detection can be used as the device for detecting the distance, for example, camera, radar, ultrasound, or lidar systems. The use of a so-called surround-view camera system is particularly advantageous, in which individual images from different areas of the vehicle's surroundings are captured by means of several cameras arranged on the vehicle and combined to form an overall image, in particular a 360° or top-view display.

[0027] Furthermore, the device according to the invention preferably comprises means for outputting information about the distance to the edge of the road to the driver and / or means for carrying out an automated parking maneuver, wherein these are preferably designed to maintain a minimum distance to the edge of the road, particularly when the parking position is reached. The means for providing information can be, for example, a loudspeaker for acoustic information and / or a display screen for visual information about the distance, comparable to known PDC (Park Distance Control) systems. The means for carrying out an automated parking maneuver can be, for example, a so-called parking assistance system, which maneuvers the vehicle from a starting position into a parking position by means of automated interventions in the driving dynamics, i.e., by means of automated longitudinal and / or lateral control of the vehicle.

Claims

[1] Method for safely parking a vehicle, wherein, upon completion of a parking manoeuvre, at least two wheels of the vehicle are turned by an automatic control in such a way that they point in the direction of travel towards the edge of the road, and wherein, in the automatic control, an upper threshold value is provided for the force with which the turning of the wheels takes place, characterized by that during the parking manoeuvre a distance to the edge of the road is continuously determined by means of a detection device, and that - the parking manoeuvre is a manual parking manoeuvre, with longitudinal and lateral control of the vehicle by the driver, and - automatic control does not occur if a minimum distance to the edge of the road is not maintained in a parking position. [2] Method according to claim 1, characterized by , that - during the automatic control, the force with which the wheels are turned is continuously determined, and - when the threshold value is reached, the automatic control of the wheels is terminated. [3] Method according to one of the preceding claims, characterized by that the threshold value is set in such a way that the automatic control is terminated as soon as at least one of the wheels touches a road edge when turning. [4] Device for implementing a method according to one of the preceding claims, with means for automatically controlling a steering system of the vehicle, wherein the device comprises means for detecting the force with which the automatic control of the wheels takes place, and wherein the device further comprises at least one device for detecting the distance to the edge of the roadway.