Method and device for operating a parking assistance system

Abstract

Method for operating a parking aid device of a vehicle (20) comprising a distance measuring unit (30) with at least one distance sensor, comprising the following steps: - Determining an extrapolated speed (v) of the vehicle (20) depending on at least one current or previous value of the speed of the vehicle (20), wherein the current or previous value of the speed of the vehicle (20) is determined depending on a measurement signal (M) of the distance sensor, - Determining a collision duration parameter (K) depending on the measurement signal (M) of the distance sensor and the determined extrapolated speed (v) of the vehicle (20) and - Generating a collision warning signal (W) when the collision duration parameter (K) falls below a predefined threshold (TH).

Description

[0001] The invention relates to a method and a device for operating a parking assistance device of a vehicle, which includes a distance measuring unit with at least one distance sensor.

[0002] Available parking space, especially in cities, is becoming increasingly scarce. For this reason, parking assistance systems are being used more frequently in vehicles to support drivers, particularly when parking.

[0003] German patent application DE 10 2005 050 576 A1 relates to a parking assistance system and parking assistance method. German patent application DE 197 45 127 A1 describes a device and a method for preventing collisions between a vehicle and an obstacle when parking the vehicle.

[0004] The object underlying the invention is to create a method and a device for operating a parking assistance device of a vehicle to support a parking process.

[0005] The problem is solved by the features of the independent patent claims. Advantageous embodiments are characterized in the dependent claims.

[0006] The invention is characterized by a method and a corresponding device for operating a parking assistance system. The parking assistance system comprises a distance measuring unit with at least one distance sensor. Depending on at least one current or previous value of the vehicle's speed, an extrapolated speed of the vehicle is determined, wherein the current or previous value of the vehicle's speed (20) is determined based on a measurement signal from the distance sensor. Depending on the measurement signal from the distance sensor and the determined extrapolated speed of the vehicle, a collision duration parameter is determined, and a collision warning signal is generated if the collision duration parameter falls below a predetermined threshold.

[0007] The parking assistance system can also be used to generate a collision warning signal. This signal predicts potential impending damage, which can still be prevented or mitigated. The collision warning signal alerts vehicle occupants to the imminent risk of collision. By appropriately selecting the threshold, a time interval remains between the generation of the collision warning signal and the anticipated collision, allowing the driver to take measures to avoid the collision. This remaining time interval depends on the predefined threshold, which can be fixed or, particularly during parking maneuvers, adjustable.

[0008] According to an advantageous embodiment of the invention, a distance signal is generated to support a parking maneuver, depending on the measurement signal from the distance sensor. The distance sensor's measurement signal is thus used in two ways: firstly, the distance signal can be generated based on the measurement signal, and secondly, the measurement signal can be used for collision warning. It is also possible that the distance signal is only generated if the collision duration parameter is greater than the predefined threshold. Because the distance signal is not generated when the collision warning signal is generated in this case, it is easier for the vehicle occupants to distinguish between an informative distance signal and the collision warning.

[0009] According to a further advantageous embodiment of the invention, the distance signal is generated when a predetermined activation condition for generating the distance signal is met. For example, the activation condition can include a switch accessible in the vehicle having a predetermined switching state. The generation of the distance signal can thus be activated or deactivated as needed, for example, by a vehicle occupant.

[0010] According to a further advantageous embodiment of the invention, a measured distance between the vehicle and an external object is determined based on the measurement signal of the distance sensor, and the collision duration parameter is determined as a function of the ratio of the measured distance to the extrapolated speed. The collision duration parameter can thus be determined easily.

[0011] According to a further advantageous embodiment of the invention, the collision warning signal is generated acoustically and / or visually in such a way that it is suitable for alerting the vehicle occupants to a risk of collision. This has the advantage that the collision warning signal is clearly distinguishable for the vehicle occupants from signals that are purely informational.

[0012] According to a further advantageous embodiment of the invention, the collision warning signal is generated acoustically with a high sound pressure level and / or a high frequency and / or a rapidly alternating sound pressure level and / or with at least two alternating dissonant frequencies and / or with two alternating very different frequencies and / or is generated optically with bright colors and / or luminous colors and / or two strongly contrasting colors and / or with alternating color intensity.

[0013] The applicable range of values ​​for sound pressure level and frequencies depends on human hearing sensitivity. It has been shown that two tones whose frequencies have complex numerical ratios, such as a major seventh 15:8, a minor ninth 32:15, and a minor second 16:15, are perceived as dissonant.

[0014] Red is one of the most conspicuous colors and is suitable as a warning color. A combination of red with white or black is also suitable as a warning color combination. Yellow in combination with black can also serve as a warning color combination.

[0015] For example, the collision warning signal could consist of a repeating sequence of five consecutive tone pulses, each lasting approximately 150 ms, with the pauses between each pulse decreasing in duration from approximately 200 ms to 100 ms. The sound pressure level of the tone pulses is, for example, 20 dB above the prevailing background noise level in the vehicle. The tone pulse has a frequency of, for example, 2 kHz. Alternatively or additionally, the collision warning signal could consist of two alternating tones at 2 kHz and 1.3 kHz. For example, in addition to the acoustically generated collision warning signal, a red flashing signal is also generated as a collision warning signal.

[0016] According to a further advantageous embodiment of the invention, the vehicle brakes automatically when the collision duration parameter falls below the predetermined threshold. This has the advantage that if the driver does not recognize the risk of a collision and / or does not brake sufficiently, a collision between the vehicle and the external object can be avoided.

[0017] According to a further advantageous embodiment of the invention, the distance signal is generated acoustically and / or visually in such a way that it is suitable for clearly indicating the detected distance. The vehicle occupants attribute an informational character to the distance signal. The distance signal thus clearly indicates the detected distance without being a warning signal. The driver can use or ignore the information provided by the distance signal as needed. Ignoring the distance signal by the driver does not result in a dangerous situation going unrecognized.

[0018] According to a further advantageous embodiment of the invention, the distance signal is generated acoustically with a low to medium sound pressure level and / or a low frequency and / or with at least two alternating harmonic frequencies and / or with two very similar frequencies and / or is generated optically with soft colors from a wavelength spectrum of approximately 400 nm to 560 nm and / or two low-contrast colors.

[0019] This has the advantage that the distance signal is clearly distinguishable from signals that have a warning character.

[0020] The applicable range of values ​​for sound pressure level and frequencies depends on human hearing sensitivity.

[0021] For example, the distance signal could consist of a repeating sequence of single-tone pulses lasting approximately 400 ms, with a pause between each pulse that depends on the detected distance. The sound pressure level of the single-tone pulse might be, for example, 10 dB to 15 dB higher than the prevailing background noise level in the vehicle. The single-tone pulse might have a frequency in the range of approximately 400 Hz to 500 Hz. Alternatively or additionally, the distance signal could, for example, consist of two or three harmonically alternating tones.

[0022] Exemplary embodiments of the invention are explained in more detail below with reference to the schematic drawings.

[0023] They show: Fig. 1 a first embodiment of a parking assistance system 1, Fig. Figure 2 shows a flowchart of an exemplary implementation of a program for operating a parking assistance system. Fig. 3 an embodiment for the generation of a distance signal D and Fig. 4 an embodiment for the generation of a collision warning signal W.

[0024] The parking assistance system 1 ( Fig. 1) A vehicle 20 comprises a parking assistance device and a device for operating the parking assistance device. The device for operating the parking assistance device comprises a processing unit 15. A signal output unit 50 is assigned to the device for operating the parking assistance device.

[0025] The parking assistance system comprises, for example, a distance measuring unit 30 with several distance sensors, which include, for example, first distance sensors 31 and / or second distance sensors 31f and / or third distance sensors 31r and / or fourth distance sensors 311. The first distance sensors 31 are, for example, located at the rear of the vehicle. The second distance sensors 31f can be located at the front of the vehicle. The third distance sensors 311 can be located on the left side of the vehicle and the fourth distance sensors 31r can be located on the right side of the vehicle. The distance sensors are each configured to measure distances to an object 40 external to the vehicle. The distance sensors are, for example, designed as ultrasonic sensors. The distance sensors are, for example, coupled to the processing unit 15 in the vehicle 20 via a data bus 17.

[0026] The computing unit 15 comprises, for example, a central processor unit with program memory and data memory. The computing unit 15 is configured to determine an extrapolated speed v of the vehicle 20 based on at least one current or previous value of the vehicle 20's speed. The computing unit 15 is, for example, coupled to a speed sensor that determines the current and / or previous value of the vehicle 20's speed. Alternatively, the computing unit 15 can be configured to determine the current and / or previous value of the vehicle 20's speed based on a measurement signal M from the respective distance sensors.

[0027] The processing unit 15 is further configured to determine a collision duration parameter K depending on the measurement signal M of the respective distance sensors and the determined extrapolated speed v of the vehicle 20. The processing unit 15 is further configured to determine a detected distance A between the vehicle-external object 40 and the vehicle 20, depending on the respective measurement signal M of the distance sensors.

[0028] The processing unit 15 is coupled to the signal output unit 50. The signal output unit 50 includes, for example, one or more loudspeakers 70 and / or a display 60. The display 60 can, for example, include a screen and / or LED display and may be located, for example, in the vehicle's dashboard. The signal output unit 50 can also include a head-up display. Alternatively or additionally, a navigation device screen can be used as the display.

[0029] The processing unit 15 generates a distance signal D, which is output via the signal output unit 50 when a predefined activation condition B for generating the distance signal D is met. The activation condition B can, for example, include a signal from a central vehicle control unit indicating that a parking maneuver is underway. This signal is output, for instance, when reverse gear is engaged in vehicle 20 and / or slow maneuvering of vehicle 20 is detected. Additionally or alternatively, the activation condition B can include a switch accessible in vehicle 20 being in a predefined switching state.

[0030] The computing unit 15 is further equipped to generate a collision warning signal W, which is output by the signal output unit 50 when the collision duration parameter K falls below a predetermined threshold TH.

[0031] The computing unit 15, for example, is additionally coupled to a brake system control and is designed to output a brake signal to the brake system control when the collision time duration parameter K falls below the specified threshold TH, thereby initiating automatic braking of the vehicle.

[0032] Fig. Figure 2 shows a flowchart of a first embodiment of a program for operating a parking assistance device, which is executed, for example, using the central processor unit with the program and data memory of the computing unit 15. In a first step S1, for example, a detected distance A between the vehicle 20 and the vehicle-external object 40 is determined, depending on the measurement signal M of the distance sensor.

[0033] In a second step S2, an extrapolated velocity v is determined based on at least one current or previous value of the vehicle 20's velocity. The current or previous value of the vehicle 20's velocity can be determined, for example, using the speed sensor. Another possibility is to determine, in the first step S1, a first measured distance between the vehicle-external object 40 and the vehicle 20 based on the measurement signal M of the distance sensor, and then to determine a second measured distance after a measurement interval. Depending on the first and second measured distances and the measurement interval duration, the current value of the vehicle 20's velocity is then determined.The extrapolated speed v can be determined, for example, from the current value of the speed of vehicle 20, or depending on the current value of the speed of vehicle 20 and a determined acceleration of vehicle 20. The acceleration can be determined, for example, depending on the current and the previous value of the speed of vehicle 20.

[0034] In step S3, the collision duration parameter K is calculated depending on a ratio of the detected distance A to the extrapolated speed v.

[0035] In a fourth step S4, the collision duration parameter K is compared with a predefined threshold value TH.

[0036] If the collision duration parameter K is less than the predefined threshold TH, a collision warning signal W is generated in a fifth step S5. If the collision warning signal W is output in the fifth step S5, the procedure returns to the first step S1.

[0037] Additionally or alternatively, in the fifth step S5, if the collision duration parameter K is less than the specified threshold TH, the vehicle can be automatically braked.

[0038] If the collision duration parameter K is equal to or greater than the specified threshold TH, the fifth step S5 checks whether the specified activation condition B for generating the distance signal D is met. If the activation condition B is met, the distance signal D is generated in step S6. Otherwise, the procedure returns to the first step S1. From the sixth step S6, the procedure returns again to the first step S1.

[0039] In the exemplary embodiment of the program for operating the parking assistance system, the collision warning signal W is generated, or, provided the predefined activation condition B is met, the distance signal D is generated, depending on the collision duration parameter K. It is also possible that if the collision duration parameter K is less than the predefined threshold value TH, the collision warning signal W and, provided the predefined activation condition B is met, the distance signal D are generated.

[0040] Fig. Figure 3 shows an embodiment for the output of the distance signal D. For example, a vehicle 20 is displayed on the screen located in the dashboard of the vehicle 20. A measurement beam from the first and second distance sensors 31 and 31f, respectively, is displayed. An area within each measurement beam containing an object 40 external to the vehicle is displayed in a first color, and another area containing no such object 40 is displayed in a second color. Neither the first nor the second color conveys a warning message. The first color is, for example, a soft yellow with a gentle transition to light green, and the second color is, for example, white.

[0041] The distance signal D can, for example, also be generated acoustically, as described in the general description. The acoustically generated distance signal D has the advantage that the driver can use it to assist with parking without having to look at a screen; instead, they can simultaneously observe the vehicle's surroundings. The loudspeakers 70 can be spatially distributed within the vehicle 20 and controlled according to the distance signal D in such a way that the vehicle occupants can perceive, through targeted sound propagation, a direction in which the external object 40 is located, thus serving as a virtual sound source.

[0042] Fig.Figure 4 shows an embodiment for the output of the collision warning signal W. For example, a vehicle is displayed on the screen, which can be located in the dashboard of the vehicle 20. A measurement beam from the first and second distance sensors 31 and 31f, respectively, is displayed. A bright red flashing circle is displayed at the position representing the point where a collision between the vehicle 20 and the external object 40 is imminent. Additionally, text can be displayed on the screen, for example, flashing in red. The collision warning signal W is also generated acoustically, for example, as described in the general description.

[0043] To assist the driver and other vehicle occupants in correctly and quickly interpreting warning signals from vehicle 20, all warning signals generated by vehicle 20 can be categorized into classes. Depending on the expected damage and the time available to avoid it, a display matrix is ​​defined, and the respective warning signals can be assigned to a class. For each class, it can be specified which sensory channels should be addressed and how strong the warning should be. The categorization of warning signals can also be used to prioritize their output when multiple warning signals are generated simultaneously. Warning signals assigned to the same class are displayed visually and / or audibly in a similar manner.

[0044] The preceding sections explained the parking assistance direction in conjunction with a parking assistance system 1. However, the parking assistance device can also be used for other assistance functions, such as maneuvering aids in narrow streets, and can therefore be operated accordingly. Reference symbol list 1 Parking assistance system 15 computing units 17 Data bus 20 vehicles 30 distance measuring unit 31, 31f, 311, 31r Distance sensor 40 Vehicle-external object 50 Signal output unit 60 ads 70 speakers A measured distance B Activation condition D distance signal K Collision duration parameter M Measurement signal TH specified threshold v extrapolated speed W Collision warning signal

Claims

Method for operating a parking aid device of a vehicle (20) comprising a distance measuring unit (30) with at least one distance sensor, comprising the following steps: - Determining an extrapolated speed (v) of the vehicle (20) depending on at least one current or previous value of the speed of the vehicle (20), wherein the current or previous value of the speed of the vehicle (20) is determined depending on a measurement signal (M) of the distance sensor, - Determining a collision time parameter (K) depending on the measurement signal (M) of the distance sensor and the determined extrapolated speed (v) of the vehicle (20), and - Generating a collision warning signal (W) when the collision time parameter (K) falls below a predetermined threshold value (TH). Method according to claim 1, wherein a distance signal (D) is generated to support a parking operation depending on the measurement signal (M) of the distance sensor. Method according to claim 2, wherein the distance signal (D) is generated when a predetermined activation condition (B) for generating the distance signal (D) is met. Method according to one of the preceding claims, wherein a detected distance (A) between the vehicle (20) and an object external to the vehicle (40) is determined depending on the measurement signal (M) of the distance sensor and the collision duration parameter (K) is determined depending on a ratio of the detected distance (A) to the extrapolated speed (v). Method according to one of the preceding claims, wherein the collision warning signal (W) is generated acoustically and / or optically in such a way as to be suitable to alert vehicle occupants to a risk of collision. Method according to one of the preceding claims, wherein the collision warning signal (W) is generated acoustically with a high sound pressure level and / or a high frequency and / or a rapidly alternating sound pressure level and / or with at least two alternating dissonant frequencies and / or with two alternating very different frequencies and / or is generated optically with bright colors and / or luminous colors and / or two strongly contrasting colors and / or with alternating color intensity. Method according to one of the preceding claims, wherein automatic braking of the vehicle (20) takes place when the collision duration parameter (K) falls below the specified threshold value (TH). Method according to one of claims 2 to 7, wherein the distance signal (D) is generated acoustically and / or optically in such a way that it is suitable to clarify the detected distance (A). Method according to any one of claims 2 to 8, wherein the distance signal (D) is acoustically generated with a low to medium sound pressure level and / or a low frequency and / or with at least two alternating harmonic frequencies and / or with two very similar frequencies and / or is optically generated with soft colors from a wavelength spectrum of 400 nm to 560 nm and / or two low contrasting colors. Device for operating a parking aid device of a vehicle (20), comprising a distance measuring unit (30) with at least one distance sensor and in which the device is configured to: - determine an extrapolated speed (v) of the vehicle (20) depending on at least one current or previous value of the speed of the vehicle (20), wherein the current or previous value of the speed of the vehicle (20) is determined depending on a measurement signal (M) of the distance sensor, - determine a collision time duration parameter (K) depending on the measurement signal (M) of the distance sensor and the determined extrapolated speed (v) of the vehicle (20), and - generate a collision warning signal (W) if the collision time duration parameter (K) falls below a predetermined threshold value (TH).

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