WO2019101515A1

WO2019101515A1 - Echolocation with direction-dependent resonator

Info

Publication number: WO2019101515A1
Application number: PCT/EP2018/080409
Authority: WO
Inventors: Markus Engel
Original assignee: Zf Friedrichshafen Ag
Priority date: 2017-11-24
Filing date: 2018-11-07
Publication date: 2019-05-31
Also published as: DE102017221021A1

Abstract

The invention relates to a directional filter (10), to the use of a directional filter (10) according to the invention in an echo-locating surroundings detection device (20) of a vehicle (1), to a surroundings detection device (20) of a vehicle (1) for echolocating an object (3) in a surrounding field of the vehicle (1), and to a method for the localization an object (3) by means of an echo-locating surroundings detection device (20) of a vehicle (1). The directional filter (10) comprises a plurality of elevations (12) and depressions (13) in a surface (11) of the directional filter (10). The elevations (12) and depressions (13) of the surface (11) form a system of resonators (14), wherein each resonator (14), depending on the respective shape, size and/or arrangement of the respective elevation (12) or depression (13), is excited in the event of an echo incidence from a specific echo incidence direction (15).

Description

Echo location with directionally dependent resonator

The invention relates to a directional filter according to claim 1, a use of a directional filter according to the invention in an echo locating surroundings detection device of a vehicle according to claim 6, an environment detection device of a vehicle for echolocation of an object in an environment of the vehicle according to claim 7 and a method for localization of an object with a Echo locating environment detecting device of a vehicle according to claim 11.

Automated driving requires the environment detection of a vehicle. Various technologies are known, such as e.g. Camera, lidar and / or radar. A disadvantage of the known technologies is the high computational complexity for signal processing.

This is where the invention starts. The invention has the object to improve the environment detection of objects.

This object is achieved by a directional filter having the features of claim 1, a use of a directional filter according to the invention in an echo locating surroundings detection device of a vehicle having the features of claim 6, an environment detection device having the features of claim 7 and by a method for localization of an object a echo-locating environment detecting device with the features of claim 11.

Further developments and advantageous embodiments are specified in the subclaims.

The directional filter according to the invention for an echo locating surroundings detection device of a vehicle has a surface with an elevation and / or a depression. The elevation and / or the depression each form a resonator.

In the case of an echo incident, the respective resonator can be excited as a function of an echo arrival direction. A filter is a mechanical or electrical device with which predetermined frequency components can be selected and / or suppressed from a spectrum of a signal. Preferred signal components are amplified by the filter. Unwanted signal components are attenuated or suppressed with the filter.

A directional filter is a filter that filters a signal direction-selective, that is, depending on the direction of incidence of the signal.

Echo location refers to the detection of the position and / or type of objects by emitting sound waves or electromagnetic waves and analyzing the waves reflected by the objects. From the running time of the waves, the distance to an object is determined. Likewise, the size of the object can be determined.

It is essential to the invention that the directional filter from which the waves reflected by the object hit the directional filter can also be determined using the directional filter according to the invention. In the event that the reflected waves are not deflected from the object to the directional filter, thus also the direction can be determined, in which the object is located. In particular, it can be determined whether the waves reflected by the object with respect to the directional filter come from the front, rear, top or bottom.

Echo denotes a signal. The waves reflected by objects are a signal that is also called an echo signal in the context of echolocation.

Examples of echolocation are radar, sonar, ultrasound, lidar, laser scanner and time-of-flight methods.

An ultrasonic sensor for detecting objects in an environment of the ultrasonic sensor is an example of an echo locating detecting device.

Vehicles are especially land-bound vehicles. An area of the directional filter is in particular a surface which is arranged in the direction of an echo incidence.

An elevation is a higher part of an area. A depression is a lower part of a surface. Folded surfaces have elevations and depressions.

A resonator is a system that can be excited to vibrate. System components of the resonator are tuned to one or more specific frequencies, so-called natural frequencies, in such a way that the resonator oscillates at a broadband excitation substantially with the natural frequencies. For example, a closed or partially open volume of air is an acoustic resonator. The elasticity of the air in a cavity leads, together with the inertia of the air, to certain resonance frequencies. The increase and / or the depression of the surface of the directional filter form a cavity and thus a resonator. By certain characteristics of the elevation and / or the depression, for example as a function of the shape, size and / or arrangement of the elevation and / or depression on the surface, the resonator formed by the respective elevation and / or depression may have a direction-dependent natural frequency.

Because the respective resonator can be excited in response to an echo incidence direction in the case of an echo incident, the directional filter is a passive filter with which pre-processing of the echo can be carried out before the echo is converted from one actual receiver into another, in particular electrical, signal becomes. Due to the dependence on the Echoeinfallsrichtung a determination of the direction from which the echo comes, and thus a localization of the echo reflecting object in the environment of the vehicle with little computational effort possible.

According to a preferred embodiment of the invention, the resonator on one of a shape, size and / or arrangement of the increase and / or the depression dependent natural frequency, wherein the directional filter is carried out, in which Echo incident depending on the Echoeinfallsrichtung a frequency band of an echo spectrum in which the natural frequency of the resonator is to select, preferably by respective amplification and / or attenuation of the echo spectrum. This creates direction-dependent minima and / or maxima in the frequency spectrum. By evaluating the minima and / or maxima in the frequency spectrum of the echo signal, the directional filter can distinguish which direction the echo comes from. In this case, the dependence on the Echoeinfallsrichtung results in particular from the shape, size and / or arrangement of the increase and / or depression.

In a particularly advantageous embodiment of the invention, the surface has an ear-relief shape with several elevations and / or depressions, preferably in the form of a helix, crus helicis, Scapha, Anthelix with Crus superius anthelicis and Crus inferius anthelicis, Fossa triangularis, Cymba conchae and Cavum conchae , Tragus, antitragus and / or lobulus auriculae. Thus, the directional filter is an ear-like direction-selective filter. The shape, size and arrangement of the elevations and depressions are not limited to the anatomy of the human ear. The elevations and / or depressions of the directional filter may also have a shape, size and / or arrangement analogous to the anatomy of an animal's ear. For example, a directional filter whose surface has the ear-relief shape of an elephant is advantageous for an infrared sensor. For an ultrasonic sensor, for example, a directional filter is advantageous, the surface of which has the ear-relief shape of a bat.

In the ear, the auricle made of cartilage acts as a directionally selective sound filter. The ear cartilage is strongly folded, so that there is a typical ear relief with numerous elevations and depressions, each bearing their own names.

The outer edge of the auricle is called helix. Parallel to the helix, separated by a narrow curved retraction called the scapha, the sickle-shaped anthelix runs as a ridge. At its cranial end, that is, pointing towards the head or pointing upwards, it divides into two separate folds, the upper, Crus superius anthelicis, and lower, Crus inferius anthelicis, Anthelix root. Between them lies a triangular constriction, the triangular fossa. The anthelix frames the actual auricle, the conchae auricularis. The conchae auricularis is an extensive depression. It is separated by an extension of the helix, the crus helicis, in two parts, the cranially located Cymba conchae and the caudal, that is to the feet or downwards Cavum conchae, which represents the transition to the external auditory meatus. Lateral, that is sideways or away from the body center in front of the cavum conchae there are two Verwölbungen, the rostral, ie in the direction of the mouth or the front end of the body located tragus and the dorsal, that is to the back of the body or a body part or Organs Antitragus. Caudal of the tragus attaches to the earlobe, the lobulus auriculae, which is free of cartilage.

With its folds and depressions, the relief of the auricle of humans as well as animals is a natural filter system for the incoming sound. The sound is refracted at the relief edges of the auricle and thus differently attenuated, depending on its frequency components. From this modulation, the brain can gain information about the spatial origin of a sound source, in particular, whether an echo comes from the front, back, up or down. This so-called directional hearing is recognized particularly clearly within the direction-determining frequency bands, the so-called Grassroots Bands.

For example, the direction from the rear is detected with more than 80% probability around the frequency of 1 kHz.

Advantageously, the directional filter is made of plastic, synthetic resin, ceramic, metal or a combination of the preceding materials. These materials are cheap and easy to work with.

The directional filter is preferably produced by an injection molding process or an additive manufacturing.

The injection molding process is a primary molding process in which the respective material is liquefied with an injection molding machine and injected under pressure into a mold, the injection molding tool. In the tool, the material passes through cooling or a cross-linking reaction again in the solid state and is removed after opening the tool as a finished part. The cavity, the cavity, of the tool determines the shape and surface structure of the finished part.

In additive manufacturing, production takes place directly on the basis of a computer-internal data model of informal or shape-neutral material by means of chemical and / or physical processes. An example of additive manufacturing is the 3D printing process.

By means of one of these methods, the directional filter can be produced particularly inexpensively.

According to the invention, a directional filter according to the invention is used in a echo-locating environment detection device of a vehicle for locating an echo source in a median plane.

The median plane is the plane that extends from top to bottom and back to front through a body center or an object center.

Thus, the direction of the echo can be determined not only in a horizontal plane, but also in the plane perpendicular to the horizontal plane. This allows a three-dimensional localization of an echo source.

The surroundings detection device according to the invention of a vehicle for echolocation of an object in an environment of the vehicle has a transmitter which is designed to transmit an echo signal. Furthermore, the surroundings detection device has a receiver which is designed to receive the echo signal after reflection at the object. Furthermore, the surroundings detection device has a direction filter which is designed to amplify and / or attenuate a frequency band from an echo spectrum as a function of an echo arrival direction. Such an environment detection device has the advantage that a directional dependence is obtained passively by the directional filter and no active methods, such as beamforming, are required. The directional filter is preferably a directional filter according to the invention.

In a development of the invention, the directional filter can be arranged in an outer structure or a paneling of the vehicle as a style element or concealed. Exterior or trim are elements such as bumper or grille / trim or trim such as chrome trim or similar. Exterior structure or cladding refers to attachments, in which one can integrate the directional filter, without it being visually striking or too sublime.

Particularly preferably, the surroundings detection device is an ultrasonic sensor.

The method according to the invention for the localization of an object with an echo-detecting surroundings detection device of a vehicle, wherein the surroundings detection device has at least two receivers, comprises the following method steps.

Determining a horizontal angle of incidence of an echo reflected on the object in a horizontal plane in which the receivers are arranged by measuring propagation time differences between the receivers and

Determining a vertical angle of incidence in a median plane with a directional filter according to the invention, wherein the directional filter surrounds at least one of the receivers.

This method allows for echolocation with a directional resonator, with the resonator surrounding a single receiver, similar to the human pinna.

Advantageously, a distance of the object is determined by the transit time differences.

In one development of the invention, a classification of the object takes place on the basis of a frequency analysis and / or pattern recognition. In the classical Freely As a rule, a signal is displayed broken down according to different frequency orders and amplitudes and / or the phase characteristic is analyzed. The pattern identifier comprises statistical elements, for example descriptive statistics with multivariate data analysis, or non-deterministic "block box" methods with artificial neural networks.

Preferably, an image, preferably a three-dimensional image, is generated by the object on the basis of the transit time differences.

For carrying out the method, an environment detection device according to the invention is preferably used.

The invention will be explained in detail with reference to the following figures. Show it:

1a is a plan view of an embodiment of an inventive

Directional filter,

1 b shows a cross-sectional view of an embodiment of a directional filter according to the invention,

1c shows an embodiment of a human ear,

2 shows an embodiment of an environment detecting device according to the invention,

3 shows an exemplary embodiment of a vehicle with an exemplary embodiment of an environment detection device according to the invention,

4a shows an embodiment of a waveform without directional filter,

Fig. 4b: an embodiment of a waveform with directional filter and Fig. 5: an embodiment of a method according to the invention.

In the figures, the same reference numerals designate the same or functionally similar reference parts. In the respective figures, the respective relevant reference parts are numbered.

1A shows a directional filter 10 having a plurality of elevations 12 and depressions 13 in an area 11 of the directional filter 10. The elevations 12 and depressions 13 of the area 11 form a system of resonators 14, each elevation 12 and each recess 13 being one Resonator 14 forms. Each resonator 14 is excited in response to the respective shape, size and / or arrangement of the respective elevation 12 or recess 13 at an echo incidence from a particular echo incident direction 15.

The directional filter 10 has an opening 16. In the opening 16, a receiver 22 can be arranged such that the receiver 22 is surrounded by the directional filter 10 similar to the auditory meatus in humans of the auricle.

The elevations 12 and depressions 13 of the directional filter 10 are shown in Fig. 1 B in cross section.

The directional filter 10 has a shape similar to an ear-relief mold 30 shown in FIG. 1C. In particular, the elevations 12 and depressions 13 of the surface 11 of the directional filter are similar in shape, size and / or orientation to the elevations 12 and depressions 13 of the ear-relief mold 30. The ear-relief mold 30 has, as an elevation 12, the so-called helix 31, which forms the Ear-relief form 30 outlined. An extension of the helix 31 is the crus helicis 31 a, which, together with the helix 31, framing a depression 13, namely the cymba conchae 35 a. A further elevation 12 is formed by the anthelix 33, which merges with a crus superius anthelicis 33a and a crus inferus anthelicis 33b as an upper and a lower anthelix root into the helix 31. The crus superius anthelicis 33a and the crus inferius anthelicis 33b surround, together with the corresponding section of the helix, a triangular depression 13, the triangular fossa 34. Between the anthelix and helix runs as depression 13 the scapha 32. A lower end of the anthelix forms as an elevation 12 the antitragus 36a. Together with an elevation 12, the tragus 36, the antitragus surrounds, as a depression 13, the cavum conchae 35b. A lower edge of the ear-relief mold 30 forms the cartilaginous earlobe, the lobulus auriculae 37.

2 shows an arrangement of two receivers 22 of an environment detection device 20. The receivers 22 are arranged at a distance 23 from one another in a horizontal plane, the XY plane. Each of the receivers 22 receives an echo from an object 3 from a respective echo incident direction 15. By measuring the propagation time differences of the echo between the two receivers 22, a horizontal incident angle 7 in a horizontal plane 8 can be determined. By directionally selective filtering with the directional filter 10, a vertical angle of incidence 9 in a median plane 2 is determined.

3 shows as a vehicle 1, for example, a passenger car with an outer structure 5 and a fairing 6. In the fairing 6, the surroundings detection device 20 is integrated. The surroundings detection device 20 has the receiver 22, which is arranged in the opening 16 of the directional filter 10 and is surrounded by it. The surroundings detection device 20 also has a transmitter 21. The transmitter 21 is, for example, an ultrasonic transmitter which emits as a signal an ultrasound having a certain duration, repetition rate, amplitude and frequency. The ultrasound is reflected from the object 3 in an environment 4 of the vehicle 1, which is for example a pedestrian, a preceding vehicle or a road safety barrier, into the room and received by the receivers 22 as an echo. The environment 4 is an area around the vehicle 1, for example a hemisphere with a radius of 100 m.

FIG. 4a shows a signal course of the echo at the location of the receiver 22 without directional filter 10, FIG. 4b correspondingly with directional filter 10. FIGS. 4a and 4b respectively plot an amplitude of the signal S in any unit, that is to say the echo, in FIG Dependence of its frequency f, in the unit Hertz, that is 1 / second. In a frequency band A, the signal S is attenuated depending on the direction. In a frequency band B, the signal S is directionally amplified. The signal S falls, for example, from behind on the directional filter. With this echo incident 15, the sonator 14 of the directional filter 10 is excited, which in comparison to the other resonators 14 of the resonator system of the directional filter 10 has a high natural frequency of, for example, 1000 hertz. The other resonators are not excited from behind because of their respective shape, size and / or arrangement in this echo incidence 15. Therefore, all other frequencies are substantially attenuated. From the maximum of the signal at 1000 hertz, it follows in turn that the echo has fallen from behind.

5 illustrates the sequence of the method for localization of the object 3 on which a signal was reflected. The horizontal incident angle 7 in the horizontal plane 8 is determined by transit time measurement from one receiver 22 to the other receiver 22. The vertical angle of incidence 9 in the median plane is determined by the directional filter 10. The directional filter 10 represents a selective directional filter which is arranged around the receiver 22 as a spatial structure. Furthermore, a distance estimation can be obtained via the transit time measurement. The type of object 3 is detected by a frequency analysis and / or pattern recognition. By processing the data of both receivers 22, a three-dimensional image of the object 3 can be generated by means of the stereo principle.

The advantage of the invention lies i.a. in that echolocation is independent of time of day. In addition, an ultrasonic sensor with which echolocation can be performed is less sensitive to environmental disturbances than environmental detection equipment. a lidar. Heretofore, ultrasonic sensors are known as distance sensors for locating objects 3 in a plane around the vehicle, e.g.

Parking sensors. With the directional filter 10 according to the invention and the surroundings detection device 20, a three-dimensional measurement of the spatial environment by means of ultrasound is made possible. Bezuaszeichen vehicle

median plane

object

environment

external structure

paneling

Horizontal angle of incidence

WL

Vertical angle of incidence

directional filter

surface

increase

deepening

resonator

Echo incident direction

opening

Surroundings sensing device

transmitter

receiver

distance

Ear relief shape

helix

a crus helicis

scapha

anthelix

a Crus superius anthelicis

b Crus inferius anthelicis

Fossa triangularis

a Cymba conchae

b Cavum conchae

tragus 36a Antitragus

37 Lobulus auriculae A frequency band

B frequency band

S signal f frequency

Claims

claims

A directional filter (10) for an echo locating environment detection device (20) of a vehicle (1) comprising

- A surface (11) having an elevation (12) and / or a recess (13), wherein

- The elevation (12) and / or the recess (13) each form a resonator (14) and

- In an echo incident, the respective resonator (14) in response to an echo arrival direction (15) can be excited.

2. directional filter (10) according to claim 1, characterized in that

- The resonator (14) has one of a shape, size and / or arrangement of the elevation (12) and / or the recess (13) dependent natural frequency, wherein

- The directional filter (10) is executed, in the echo incident depending on the Echoeinfallsrichtung (15) a frequency band of an echo spectrum in which the natural frequency of the resonator (14) is to select, preferably by respective amplification and / or attenuation of the echo spectrum.

3. directional filter (10) according to claim 1 or 2, characterized in that the surface (11) has an ear-relief mold (30) with a plurality of elevations (12) and / or depressions (13), preferably in the form of a helix (31), Crus helicis (31a), Scapha (32), Anthelix (33) with Crus superius anthelicis (33a) and Crus inferius anthelicis (33b), Fossa triangularis (34), Cymba conchae (35a) and Cavum conchae (35b), Tragus (35) 36), antitragus (36a) and / or lobulus auriculae (37).

4. directional filter (10) according to any one of the preceding claims, characterized in that the directional filter (10) made of plastic, synthetic resin, ceramic, metal or a combination of the preceding materials is made.

5. directional filter (10) according to any one of the preceding claims, characterized in that the directional filter (10) is made by an injection molding process or an additive manufacturing.

6. The use of a directional filter (10) according to one of claims 1 to 5 in an echo locating surrounding Umfassungsfassungseinrichtung (20) of a vehicle (1) for locating an echo source in a median plane (2).

7. surroundings detection device (20) of a vehicle (1) for Echoortung an object (3) in an environment (4) of the vehicle (1) having

a transmitter (21) configured to send a signal,

a receiver (22) adapted to receive the signal after reflection on the object (3), and

- A directional filter (10), which is designed to amplify a frequency band of an echo spectrum in response to an Echoeinfallsrichtung (15) and / or to attenuate.

8. surroundings detection device (20) according to claim 7, characterized in that the directional filter (10) is a directional filter (10) according to one of claims 1 to 5.

9. surroundings detection device (20) according to claim 7 or 8, characterized in that the directional filter (10) in an outer structure (5) or a lining (6) of the vehicle (1) as a style element or concealed can be arranged.

10. environment sensing device (20) according to any one of claims 7 to 9, characterized in that the Umfeldfassungseinrichtung (20) is an ultrasonic sensor.

11. A method for localization of an object (3) with an echo locating surroundings detection device (20) of a vehicle (1), wherein the surroundings detection device (20) has at least two receivers (22), with the following method steps:

Determining a horizontal incident angle (7) of an echo reflected on the object (3) in a horizontal plane (8) in which the receivers (22) are arranged by measuring propagation time differences between the receivers (22) and - Determining a vertical angle of incidence (9) in a median plane (2) with a directional filter (10) according to one of claims 1 to 5, wherein the directional filter (10) surrounds at least one of the receiver (22).

12. The method according to claim 1 1, characterized in that a distance of the object (3) is determined by the transit time differences.

13. The method of claim 1 1 or 12, characterized in that a classification of the object (3) based on a frequency analysis and / or pattern recognition.

14. The method according to any one of claims 1 1 to 13, characterized in that of the object (3) based on the differences in transit time an image, preferably a three-dimensional image, is generated.

15. The method according to any one of claims 1 1 to 14, characterized in that for carrying out the method, an environment detecting device (20) is used according to one of claims 7 to 10.