Method and device for assisting a driving maneuver of a motor vehicle

Abstract

A method for supporting a driving maneuver of a motor vehicle, wherein this support is based on sensor-based detection of the vehicle environment using at least one ultrasonic sensor, wherein the sensitivity of this at least one ultrasonic sensor is adjusted based on input data characteristic of the roughness of the road surface currently being driven on by the motor vehicle, and wherein the sensitivity of the at least one ultrasonic sensor is reduced with increasing roughness of this road surface, characterized in that the input data for adjusting the sensitivity of this at least one ultrasonic sensor are not provided by the ultrasonic sensor and that the sensitivity of this at least one ultrasonic sensor is adjusted as soon as and as long as it is active.

Description

[0001] The present invention relates to a method and a device for assisting a driving maneuver of a motor vehicle, according to the preambles of the independent claims.

[0002] In current and future parking assistance systems, the vehicle is steered along a pre-planned path (trajectory) during the parking process. This path or trajectory is planned based on sensor-based detection of the vehicle's surroundings using ultrasonic sensors.

[0003] In practice, this presents the problem that different parking scenarios generally require adjustments to the sensitivity of the ultrasonic sensors. While some scenarios, such as the sensor-based detection of relatively small objects or obstacles like stakes or posts, require relatively high sensitivity, other scenarios (such as driving over gravel, crushed stone, or scree) favor comparatively low sensitivity. Otherwise, with high sensitivity, pebbles or rock fragments could be misinterpreted as objects or obstacles. In practice, a compromise is often chosen regarding the sensitivity setting of the ultrasonic sensors, considering the different possible scenarios.

[0004] From DE 101 24 909 A1, inter alia, a method and a device for operating a radar sensor arrangement are known, wherein a number of adjacent, largely synchronized individual sensors are used to determine the position of a target object, e.g. a pole or a wall.

[0005] From DE 10 2004 005 960 A1, which discloses a method with the features of the preamble of claim 1, inter alia, an obstacle detection device, in particular a parking aid, is known which has a sensor device for transmitting a signal and for receiving an echo signal representing the signal reflected by an obstacle. Furthermore, an evaluation device for evaluating the received echo signal with regard to the presence of the obstacle and an adjustment device for automatically readjusting the sensor device and / or the evaluation device such that the evaluation device detects the obstacle with a desired sensitivity are provided. The adjustment device performs the readjustment by first correcting a suboptimal (i.e.,The system sets a (too sensitive) sensitivity setting and then automatically adjusts the sensitivity incrementally until the desired optimal sensitivity is reached. In each successive adjustment step, the sensor emits a signal, and the evaluation unit receives the components of this signal reflected, for example, by the road surface, as an echo signal.

[0006] From EP 1 314 047 B1, inter alia, a sensor system for distance determination is known, which comprises a sensor unit and an amplification unit, wherein the sensor unit operates in different detection ranges during a detection cycle, generating at least one sensor signal depending on the detection range. The amplification unit amplifies the sensor signal depending on the value of an amplification parameter.

[0007] German patent DE 10 2005 061 396 A1 discloses, among other things, an ultrasonic sensor for parking space localization in which the sensitivity parameters and / or characteristic curves are adjusted based on temperature and / or humidity, whereby, for example, output signals from a vehicle's own rain sensor or humidity sensor can be used. This is intended to enable reliable parking space measurement even under varying weather conditions.

[0008] From DE 10 2004 038 496 A1, inter alia, a method and a device for measuring the distance of an obstacle located in the vicinity of a motor vehicle are known, wherein, in order to ensure a reproducible detection performance of the sensors under changing environmental conditions, namely temperature data and / or humidity data and / or air pressure data, the relative ratio between the distance-dependent echo amplitude of an echo signal and a threshold value determining the detection of the received echo signal is adjusted, wherein the air pressure can also be determined from the GPS coordinates of a navigation system using the barometric altitude formula.

[0009] From EP 2 144 081 A1, inter alia, a method and a device for controlling sensors of an environment detection system are known, wherein the detection range of at least one sensor is controlled depending on the distance of the chassis to the ground, and wherein the loading state of the vehicle is determined via an evaluation electronics.

[0010] From DE 10 2012 203 091 A1, among other things, a method for detecting objects in the vicinity of a motor vehicle is known, wherein a threshold used to filter out echo signals, which is defined by a characteristic curve, is set to a smaller value for weakly reflective surfaces than for strongly reflective surfaces.

[0011] DE 10 2013 223 367 A1 discloses a method in which the surface condition of a roadway is determined using a camera system and made available to other assistance systems.

[0012] DE 10 2009 012 128 A1 discloses a method for determining the roughness of a road surface based on rotational speed information from a wheel of the vehicle. Frequency amplitudes are determined from the rotational speed information, and from these, a roughness value of the road surface is derived.

[0013] It is an object of the present invention to provide a method and a device for supporting a driving maneuver, whereby a more reliable detection or evaluation of the vehicle environment is made possible.

[0014] This problem is solved by the method according to the features of independent claim 1 or the device according to the features of dependent claim 7.

[0015] In an inventive method for supporting a driving maneuver of a motor vehicle, this support is based on sensor-based detection of the vehicle environment using at least one ultrasonic sensor, wherein the sensitivity of this at least one ultrasonic sensor is adjusted based on input data characteristic of the roughness of the road surface currently being driven on by the motor vehicle, which is not provided by the ultrasonic sensor, wherein the sensitivity of the at least one ultrasonic sensor is reduced with increasing roughness of this road surface, and wherein the sensitivity of the at least one ultrasonic sensor is adjusted as soon as and as long as it is active.

[0016] According to one embodiment, this input data is provided by at least one sensor that does not correspond to the ultrasonic sensor.

[0017] According to one embodiment, the input data includes GPS data from a GPS sensor.

[0018] According to one embodiment, the input data includes sensor data from at least one wheel sensor of the motor vehicle.

[0019] According to one embodiment, the input data includes camera data from a camera sensor of the motor vehicle.

[0020] According to one embodiment, the driving maneuver is a parking maneuver or a turning maneuver.

[0021] The invention further relates to a device for assisting a driving maneuver of a motor vehicle, wherein the device performs a method with the aforementioned features. For advantages and preferred embodiments of the device, reference is made to the preceding descriptions in connection with the method according to the invention.

[0022] Further embodiments of the invention can be found in the description and the dependent claims.

[0023] The invention is explained in more detail below with reference to an exemplary embodiment and the accompanying figure. The only Fig. Figure 1 serves to explain a method according to the invention.

[0024] The following section refers to the flowchart of Fig. 1 A typical sequence of the method according to the invention is described using an exemplary embodiment.

[0025] According to Fig. 1. In a first step, S10 activates the ultrasonic sensors (this activation can be done manually by the driver or automatically).

[0026] In a subsequent step S20, the condition of the road surface is determined, i.e., the ground surface or the road surface properties of the roadway currently being traveled on by the vehicle. This determination is carried out according to Fig.1 taking into account input data 21, 22 and 23.

[0027] Specifically, the input data 21 comprises GPS data and navigation maps suitable for determining and evaluating the road type and surface condition of the vehicle. Input data 22 includes data from wheel sensors and wheel speed sensors, such data enabling, in particular, conclusions to be drawn about the deformability (or non-deformability) of the road surface currently being traveled on by the vehicle. Input data 23 comprises camera data from a camera system, suitable for characterizing the surface structure and surface condition.

[0028] In a subsequent step S30, a query is performed to determine whether a rough (e.g., bumpy) surface is present – ​​for example, as a result of the vehicle currently driving on rough terrain. If so, in step S40, predetermined settings for the ultrasonic sensors are selected according to a comparatively low sensitivity. Otherwise, in step S50, predetermined settings for a comparatively higher sensitivity of the ultrasonic sensors are selected. The invention is thus based, in particular, on the concept of using GPS, camera, and / or wheel sensor data to determine the surface condition of a vehicle.

[0029] After the sensitivity of the ultrasonic sensors has been adjusted accordingly, step S60 checks whether the ultrasonic sensors are still active. If so, the process returns to step S20, i.e., the subsurface properties are determined again. Otherwise, the procedure ends (step S70).

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