DE102009053807A1 - A method of assisting a driver when parking a vehicle - Google Patents

Abstract

The invention relates to a method for assisting a driver of a vehicle when parking. The procedure is activated as soon as the driver sets the reverse gear of the vehicle. The method comprises detecting obstacles (2, 4, 5) in the area of the trajectory predetermined by the steering angle from the data of at least one environmental sensor (1) and applying a corrective steering torque in the direction determined by a detected obstacle (2, 4 , 5) points away to facilitate the driver to avoid the obstacle (2, 4, 5).

Description

The invention relates to a parking system that supports the driver when parking in a parking space.

The DE 102004039179 A1 shows a parking aid for a motor vehicle, in which the instructions to the driver are made clearer and easier. A disadvantage of this solution is that the driver must activate extra selection means (eg switches) and must observe the instructions of the parking assistance system.

Broad distribution, especially in the Asian market, has camera-based systems. In these systems, a rear-mounted camera equipped with a wide-angle lens provides an image of the rear and side space commonly displayed on the navigation system display. This image is usually rectified for improved representation and provided with an overlay of color lines that point the driver into the possible parking space. For parking, the driver can now orient himself to the auxiliary lines. An example of such a parking assistant shows EP 1160146 A2 ,

However, the driver typically has difficulty in getting the correct orientation via the steering wheel, especially in the beginning, in order to maneuver the vehicle quickly into the parking space - especially in tight situations.

Recently, fully automatic parking assistants are on the market. For automatic parking assistants, parking spaces have to be precisely measured, trajectories for possible parking paths must be calculated, and a control procedure is required for maintaining the setpoint trajectory during parking. By way of example, this is the DE 102007002264 A1 called.

The disadvantages of the supported or automatic parking according to the prior art thus consist in that the parking operation must be initiated by an additional and usually not intuitive operation or that only by the presentation of guidelines, the leadership of the vehicle is not automatically in the right direction he follows.

Object of the present invention is to overcome the mentioned disadvantage.

An essential feature of the method described here is that in the area of the lane lines or auxiliary lines predetermined by the steering angle and / or between them, i. H. in the range of the predetermined by the steering angle trajectory for possible obstacles is sought. This search can be performed using common image processing algorithms, such as optical flow (as the vehicle is in motion) or using a grid-based approach.

In contrast to automatic parking systems, no possible parking space needs to be identified, no trajectory calculated in the possible parking space and no control algorithm that corrects the deviation from the target trajectory, go through. It is, as described above, only looking for obstacles.

The second essential feature of this method is that, if an obstacle such. B. a curb or a vehicle is detected, the driver is led away by a supporting steering torque from this obstacle. As a result, the driver is immediately steered in the right direction, making parking much easier.

Another major simplification is that to activate the function no extra control switches are required, but only the reverse gear must be engaged. The driver does not have to perform any additional operations, but parks as usual, but is already guided by the anticipatory obstacle detection timely in the right direction.

The method is designed to assist the driver when parking in rear (head parking spaces) and side parking spaces.

The proposed supportive steering torque can be overridden by the driver at any time to z. B. approach another parking space. He remains at all times - in contrast to the automatic parking - in control of the vehicle.

The advantages of the method according to the invention are seen in the fact that the driver is supported only gently, this support under certain circumstances not perceive and parking is still significantly simplified.

This allows an untrained driver with this assistance system easily and quickly park in any suitable parking space, as already anticipated a possible obstacle is detected, thereby timely a corrective steering torque guides the driver in the right direction. Multiple forwards and backwards is thus avoided. The system can be operated intuitively, as no change is made to the usual parking procedure and the parking process does not have to be initiated by an extra switch or push button. The procedure offers beside the Parking procedure even assistance in reversing in general, since here too the avoidance of potential obstacles is supported.

• 1. Rückwärtsgang einlegen.
• 2. Optional: Kamerabild im Display (z. B. Navi oder im Rückspiegel integriertes Display)
• 3. Hilfslinien entsprechend Lenkwinkel berechnen.
• 4. Optional: Hilfslinien entsprechend Lenkwinkel darstellen
• 5. Potentielle Hindernisse z. B. mit optischem Fluss oder Grid-basiertem Ansatz in einem über die Hilfslinien hinausgehenden Bereich erkennen.
• 6. Liegen die Hindernisse ausreichend außerhalb der Hilfslinien, wird kein unterstützendes Lenkmoment aufgebracht.
• 7. Liegt zwar ein Hindernis innerhalb der Hilfslinien, es ist jedoch ausreichend Platz zum Einparken vorhanden, wird mit Hilfe eines korrigierenden Lenkmomentes der Fahrer in die richtige Richtung geführt.
• 8. Liegen Hindernisse innerhalb der Hilfslinien und es ist nicht ausreichend Platz zu Einparken vorhanden, so kann z. B. durch leichten Bremseingriff oder durch eine leichte Gegenkraft bei einem Gaspedal mit einer solchen Funktionalität („Force Feedback Pedal”) oder durch leichtes Rütteln in der Lenkung (Lenkradvibration) und durch entsprechende Darstellung im Display oder eine akustische Warnung der Fahrer auf diesen Umstand aufmerksam gemacht werden.
• 9. Da der Fahrer die Unterstützung jederzeit übersteuern kann, kann der Fahrer den Einparkvorgang fortsetzen, um z. B. absichtlich einen Bordstein überfahren zu können.

An algorithm for parking could consist of the following function blocks:

• 1. Engage reverse gear.
• 2. Optional: camera image in the display (eg navigation device or integrated display in the rearview mirror)
• 3. Calculate auxiliary lines according to steering angle.
• 4. Optional: show auxiliary lines according to steering angle
• 5. Potential obstacles z. B. recognize with optical flow or grid-based approach in a beyond the auxiliary lines area.
• 6. If the obstacles are sufficiently outside the auxiliary lines, no supporting steering torque is applied.
• 7. While there is an obstacle within the guides, but there is enough space to park, the driver is guided in the right direction by means of a corrective steering torque.
• 8. If there are obstacles within the guides and there is not enough space to park, so can. B. by slight braking intervention or by a slight drag on an accelerator pedal with such functionality ("Force Feedback Pedal") or by slight shaking in the steering (steering wheel vibration) and by appropriate representation in the display or an audible warning of the driver on this circumstance be made.
• 9. Since the driver can override the support at any time, the driver can continue the parking process to z. B. intentionally run over a curb.

• – dem Erkennen von Hindernissen im Bereich der durch den Lenkwinkel vorgegebenen Trajektorie
• – Aufbringen eines korrigierenden Lenkmomentes, um dem Hindernis auszuweichen.

The central features of this procedure consist of:

• - The detection of obstacles in the range specified by the steering angle trajectory
• - Apply a corrective steering torque to avoid the obstacle.

These two steps are repeated until the parking process is completed.

The system can be extended in the direction that, as soon as the reverse gear is engaged, the camera scans for possible parking spaces, z. As mentioned above, two flanking vehicles. The system can then calculate the setpoint trajectory in order to guide the driver even more purposefully into the desired parking space.

• – Wie oben erwähnt kann die Hinderniserkennung auf Basis des optischen Flusses erfolgen, bei dem nachfolgende Bilder in einem Raster zur Deckung gebracht werden. Die Berechnung radialer Abstände zur Kamera und der Vergleich mit nachfolgenden örtlich und zeitlich versetzten Bildern liefert ein 3D-Höhenprofil, in dem auch Bordsteine gut erkannt werden können (siehe 1).
• – Eine weitere Möglichkeit zur Hinderniserkennung oder zur Verbesserung der oben beschriebenen Hinderniserkennung könnte sich auf einem Grid basierten Ansatz stützen, bei dem der Bereich hinter dem Fahrzeug im der Umgebung der Führungslinien und zwischen den Führungslinien durch ein ortsfestes Gitter (Grid) aufgespannt wird. Einzelne Punkte dieses Gitters werden durch die vom Sensor erkannten Hindernisse befüllt (siehe 2)

Further training relates to the type of obstacle detection in connection with the rear-guided parking:

• - As mentioned above, the obstacle detection can be based on the optical flow, are brought in the subsequent images in a grid. The calculation of radial distances to the camera and the comparison with subsequent spatially and temporally offset images provides a 3D height profile, in which curbs can be well recognized (see 1 ).
• - Another way of detecting obstacles or improving the obstacle detection described above could be based on a grid-based approach, in which the area behind the vehicle in the vicinity of the guidance lines and between the guidance lines is spanned by a stationary grid. Individual points of this grid are filled by the obstacles detected by the sensor (see 2 )

A grid-based approach is initially sensor-independent. It could also be used for this purpose a laser scanner, a radar sensor or a camera or stereo camera. Likewise, one from the merger of z. B. radar sensor and camera data generated signal can be used.

1a shows a vehicle with a rear-mounted environment sensor ( 1 ), in this embodiment, a camera. The vehicle is standing lengthways on the lane next to a curb ( 2 ).

1b shows a calculated from the optical flow height profile of the side and rear vehicle environment. For easier orientation, the vehicle is shown with the rear-side environment sensor. The white markings represent overrun areas found here ( 3 ). The relevant area 1b is in 1c outlined again: a first passable (since plane) area ( 3 ) is bounded by the curb ( 2 ), slight elevation, and in the background of a non-drivable area ( 4 ) in which other vehicles are located. At the curb ( 2 ) is followed by another plane (passable) area ( 3 ) on the left side, which is finally from a non-traversable area ( 5 ) is limited to non-determinable height in which, for example, a house wall is located.

2a shows a grid or grid of width B and length L with corresponding B × L cells in front of an environmental sensor ( 1 ), which determines the coordinates (x, y) of obstacles in the vicinity of a vehicle. 2 B now shows a representation of a vehicle environment that is registered in such a grid. Black cells mean a flat, passable area ( 3 ). Way cells represent an obstacle, in the case shown, this is a curb, which can thus be reliably detected.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004039179 A1 [0002]
• EP 1160146 A2 [0003]
• DE 102007002264 A1 [0005]

Claims (7)

A method of assisting a driver of a vehicle when parking, which is activated as soon as the driver stops the vehicle's reverse gear, comprising: - detecting obstacles ( 2 . 4 . 5 ) in the region of the predetermined by the steering angle trajectory from the data of at least one environment sensor ( 1 ) - applying a corrective steering torque in the direction of a detected obstacle ( 2 . 4 . 5 ) points away to the driver avoiding the obstacle ( 2 . 4 . 5 ) to facilitate. Method according to claim 1, wherein at least one camera is used as environmental sensor ( 1 ) is provided and the method of optical flow 3D height profiles are determined from the image data and from this obstacles ( 2 . 4 . 5 ) and possible parking spaces ( 3 ) be identified. The method of claim 1 or 2, wherein at least one beam sensor or a stereo camera as environment sensor ( 1 ) and from the sensor data the position of obstacles ( 2 . 4 . 5 ), the location of the obstacles ( 2 . 4 . 5 ) is entered in a coordinate grid representing the vehicle environment. Method according to one of the preceding claims, in which a warning is issued to the driver when an obstacle ( 2 . 4 . 5 ) is in the range given by the steering angle direction and the driver when parking directly on a collision with the obstacle ( 2 . 4 . 5 ) is heading. The method of claim 4, wherein the warning comprises a light braking intervention, a vibration of the steering wheel, a slight reaction force in an accelerator pedal with such functionality, a warning in a display element and / or an audible warning. Method according to one of the preceding claims, wherein using the sensor data, a target trajectory is calculated to a detected parking space and this target trajectory is used to specifically support the driver by the application of corrective steering torque when parking. Method according to one of the preceding claims, wherein a graphical representation of the vehicle environment is displayed on a display in the vehicle and on the display auxiliary lines for representing obstacles ( 2 . 4 . 5 ), possible parking spaces ( 3 ) and / or target trajectories.

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