Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/55—Specular reflectivity
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
  • B60S1/00—Cleaning of vehicles
  • B60S1/02—Cleaning windscreens, windows or optical devices
  • B60S1/04—Wipers or the like, e.g. scrapers
  • B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
  • B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
  • B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
  • B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
  • B60S1/0833—Optical rain sensor
  • B60S1/0844—Optical rain sensor including a camera
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/94—Investigating contamination, e.g. dust
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
  • G06V20/00—Scenes; Scene-specific elements
  • G06V20/50—Context or environment of the image
  • G06V20/56—Context or environment of the image exterior to a vehicle by using sensors mounted on the vehicle
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/94—Investigating contamination, e.g. dust
  • G01N2021/945—Liquid or solid deposits of macroscopic size on surfaces, e.g. drops, films, or clustered contaminants
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/55—Specular reflectivity
  • G01N21/552—Attenuated total reflection
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2201/00—Features of devices classified in G01N21/00
  • G01N2201/06—Illumination; Optics
  • G01N2201/062—LED's

Definitions

• the invention relates to a method for detecting raindrops on a disc by means of a lighting ⁇ source and a camera.
• WO2010 / 072198 AI describes rain detection with the aid of a camera, which is used for automotive driver assistance functions.
• bifocal optics is used that reflects a portion of the wind ⁇ protection disc keen on a partial area of the image sensor chip and image the camera.
• a rain sensor is also proposed by means of a camera, which provides large-area illumination of the passage window of the camera opening angle with the window.
• the camera is nearly focused at infinity and therefore can be used simultaneously for Augustas ⁇ sistenzap bearingen. Because of the image on the far field, raindrops are only noticeable as disturbances in the image, which can be detected by complex differential measurements of those with in Synchronization of the pixel clock pulsed or modulated light recorded images are detected.
• This object is achieved by a method for detecting rain on the outside of a disc.
• a method for detecting rain on the outside of a disc By means of a camera arranged behind the pane, which is focused on a distant area in front of the pane, and an illumination source for producing at least one light ray directed onto the pane.
• the illumination source directs the at least one light beam onto the disk such that at least one beam reflected from the outside of the disk strikes the camera.
• the camera captures a trailing formation of the at least one reflected from the outside of the disc beam.
• the structure of the image of the at least one reflektier ⁇ th from the outer side of the disk beam is evaluated in a particular Schmverarbei ⁇ processing for classifying the type of rain or precipitate on the outside of the disk.
• the invention has the advantage that the type of rain or precipitation can be determined with a vehicle camera, in particular with a driver assistance camera, while the actual function of the camera is hardly affected thereby.
• the evaluation of the structure of the image of the at least one reflected from the outside of the disc beam comprises ⁇ a pattern or texture recognition.
• the texture and / or pattern recognition can in particular be a classification based on trained textures and / or patterns, eg by means of a neural network.
• the evaluation of the structure of the image of the at least one beam reflected from the outside of the disk comprises a comparison of present with stored and / or learned structure characteristics.
• the presence of a ⁇ individual raindrop on the outer side of the disk is ER withdrawn from a continuous portion in the image of the at least one reflected from the outside of the disc beam with less intensity.
• the presence of Niesei- or mist on the outside of the disc is detected preferably of streaks in the image of the Minim ⁇ least one reflected from the outer side of the disc beam.
• the loading ⁇ illumination source directs the at least one light beam onto the disc so that at least two spatially from the inner and outer side of the disk as reflected rays separated beams impinge on the camera.
• the camera takes an image of the at least one reflected by the Au ⁇ .seite of the disk and a beam Abbil ⁇ extension of the at least one reflected from the inside of the disc beam.
• the latter can be evaluated as Referenzabbil ⁇ tion.
• a first image is first recorded with the illumination source switched off with the camera. Then a two ⁇ tes image when the lighting source is adoptednom ⁇ men.
• the difference image from the second and first image is ge ⁇ forms.
• the structure of the image of at least one ⁇ reflectors oriented on the outer side of the disk beam for detecting the type of precipitation or rain on the outside of the wheel is evaluated.
• visible light as illumination must be taken to ensure that traffic part ⁇ participants will not be disturbed by the lighting.
• a short visible light pulse adapted to the intensity of the external brightness. This would require only a short exposure time and image capture time for the rain sensor image, which in turn has little effect on the driver assistance function.
• Such a light pulse would be perceived in daylight only when looking directly at the lighting. At night, little light is needed for rain detection.
• the intensity may be downloaded are gere ⁇ gelt, so that the illumination is not troublefree ⁇ acts at night rend.
• a preferred adaptation of the illumination intensity - un ⁇ depending on the wavelength range used - brings a further advantage.
• the rain sensor light reflections are also clearly visible during the day and at night it is avoided that the images saturate and thus an evaluation of the structure of the image (s) would be prevented.
• a temporal change of the imaged by the image sensor of the camera ⁇ structures of the light reflected at the outer side of the disc beam can be determined.
• a sequence of pictures can be taken with the camera.
• the camera is used for one or more additional driver assistance functions, which are based on an evaluation of the focussed distant range.
• the invention further relates to a device for detecting rain or precipitation, which comprises a camera and a lighting source.
• the camera is arranged behind ei ⁇ ner window, in particular inside a driving ⁇ zeugs example behind a windshield, and focused to a remote region which lies in front of the disc.
• the Ka ra ⁇ preferably comprises a lens for focusing and an image sensor such as a CCD or CMOS sensor.
• the illumination source for generating at least one light beam directed onto the pane directs the at least one light beam onto the pane such that at least one beam (or partial beam of the light beam directed onto the pane) from the outside of the pane impinges on the camera.
• the illumination source may be formed as one or more light-emitting diodes (LEDs) or as a light band.
• Image processing means for evaluating the structure of the image of the at least one beam reflected from the outside of the disk are provided.
• Means for classifying the type of rain or precipitation on the outside of the disk are provided, whose classification is based on the evaluation of the structure of this figure.
• the illumination source directs the at least one light beam onto the pane in such a way that the one from the inside and outside of the pane reflected rays as at least two spatially separated rays impinge on the camera.
• the at least two rays impinging on the camera can thereby be spatially separated.
• the structure of the separate illumination reflexes can be evaluated.
• the (di ⁇ RA) on the inside of the disk reflected beam incident on the camera used here may preferably serve as a reference picture, since the structure of the image of this beam in the presence or absence of rain drops on the outside of the disc remains unchanged. If the structure of the image of this beam nevertheless changes, it can be concluded that there is fogging or the like on the inside of the pane.
• the lighting can be advantageously realized on individual Leuchtdio ⁇ , for example, are arranged in series. It could alternatively be used a light band. ⁇ preference, a sufficiently directed Abstrahlcha ⁇ rakterizing of, for example less than + 20 ° is ensured here.
• the illumination source is structurally integrated in the camera or in the Genosu ⁇ se of the camera.
• the illumination source can preferably be arranged under a screen or a view funnel of the camera within the camera body.
• the illumination source advantageously generates light in the infrared wavelength range
• the viewing diaphragm is in the infrared wavelength range at least in a partial region which is located above the illumination source or in the beam direction of the illumination source permeable.
• the illumination source can in this case be arranged in particular on a circuit carrier or a circuit board of the camera.
• the illumination source produces light having only egg ⁇ ner wavelength in a certain wavelength range, such as infrared in the (near) wavelength range.
• a first spectral filter is arranged in the region in which run the at least two spatially separated reflected beams.
• the first spectral filter transmits light having a wavelength in the ⁇ sem specific wavelength range at least largely by (eg infrared transparent).
• a second spectral filter is disposed in the region of the beam path in which the at least two spatially separated reflected beams do not extend, the second spectral filter blocking light having a wavelength in the particular wavelength range (e.g., infrared cutoff filters).
• the first or both spectral filters can preferably be applied directly to pixels of the image sensor of the camera.
• the illumination source generates a focused light beam.
• the light beam generated by the illumination source can be directed onto the disc by a light guide such as a glass fiber ⁇ .
• a light guide such as a glass fiber ⁇ .
• Fig. 1 shows schematically the basic principle of a possible arrangement of the illumination source and camera with beam paths in a dry disc
• FIG. 3 shows the modified beam paths with a mirror image of the light source
• FIG. 4 shows reflections of illumination beams imaged by an image sensor of a camera, which indicate the presence of a single raindrop in the detection area
• Fig. 5 shows reflected reflections of illuminating rays suggesting sneezing and / or drizzle on the disc;
• Fig. 6 shows schematically the beam paths with a mirror image of the light source when fitting on and reflection on the In ⁇ nenseite the disc and
• FIG. 7 shows reflections of illumination beams which suggest fogging on the inside of the disk.
• Fig. 1 illustrates the principle of operation of an embodiment ⁇ form of the invention.
• the rain detection presented here is based on a far-field focused camera (1) and illumination (3).
• a light beam (h) generated by an illumination source (3) is thus applied to the screen.
• the light of the illumination source can be bundled.
• reflected portion (rl) of the main beam serves as a reference beam.
• the portion which is transmitted into the disk (t1) is used as the measuring beam (r2) at the disk-air interface (or disk outside
• infrared light can be used, particularly near the set ⁇ a CCD or CMOS image chip having a high sensitivity, as a rule, for the.
• the light source (3) is preferably syn ⁇ chron to modulate with the image read-out clock partially or completely time ⁇ Lich, so that ren simple Differenzverfah- disorders can be deducted. This is a way to improve the signal-to-noise ratio.
• a further possibility consists in appropriate spectral filtering:
• the section of the image chip, to which the Strah ⁇ lencrue (rl, r2 / r2>) meet, can be provided with a spectral band pass, a high transmittance for the wavelength of illumination (3) having.
• FIG. 3 serves to illustrate the fact that the illumination reflex (9) of the measuring beam (r2 or r2 A ) is shown as a blurred image mirrored on the outside of the pane. of the light source (3) appears.
• the mirror images of the light source (3 ⁇ ) and the light beam (h A ) are shown schematically by dashed lines.
• Fig. 4 shows in the upper part (6) of the image sensor (5), which serves the rain detection, each seven pairs of illumination reflections (8, 9), for example, of seven LEDs as the illumination source (3) are generated. These are due to the focus on infinity camera (1) not sharply displayed but perceptible. In particular, the structure of the illumination reflexes can be evaluated.
• the lower BL LEVEL ⁇ tung reflexes (8) are generated by on the inside (2.1) of the windshield (2) reflected rays (rl), the upper (9) on the outside of the windshield reflected rays (r2, r2 A) produced.
• the light beam pairs (8, 9) should not interfere with the driver's assistant film (7).
• the region (6) is selected for rain detection to the disc (2), which is outside the remplias ⁇ sistenz Kunststoffes (7) on the image chip (5).
• An illumination reflex from the outer windshield (9) over which a single raindrop (4) lies has a dark contiguous area or recess (10).
• this illumination reflex (9) transmits the information in whether rain (4) on the outside (2.2) of the disc (2) is present, and its structure could be allei ⁇ ne used as the measurement signal.
• the evaluation can be performed for example by a pattern recognition or by a comparison of present with stored and / or learned structural characteristics, such as dark contiguous partial regions or streaks within an illumination ⁇ reflexes (9).
• comparisons of the structure of several ⁇ rer this illumination reflections (9) with each other and / or by analysis of the temporal changes in the structure at least one of these lighting reflections (9) successes can gen.
• a comparison of the structure of a reflection from the disc outer surface to the corresponding can Reflex be performed by the disk inside as a reference structure.
• an infrared blocking filter can additionally be vapor-deposited on a cover glass of the image chip (5) up to the upper edge of the driver assistance area (7).
• a bandpass filter for the wavelength of the illumination (3) can be deposited over the rain sensor detection area (6).
• the filters could also be applied directly to the pixels of the image sensor (5).
• An advantage here would be a process that corresponds to the current application of the pixel color filter.
• the two regions (6, 7) can be separated with pixel precision, thus avoiding additional mechanical tolerance requirements resulting from the production process.
• one would dispense with the application of color filters (R, G, B) for the rain sensor area (6) and thereby increase the sensitivity for rain detection.
• FIG. 4b what has been described is shown on the basis of a real photo (taken by the image sensor (5) of the camera (1)) in order to prove the feasibility of this embodiment: in each case three blurred illumination reflections (8 or 9) from the interior (2.1) and outer side (2.2) to know ER, with the left outer reflex is partially influenced by a ⁇ an individual raindrops.
• Fig. 5 shows in principle a section of the Regensensorbe ⁇ Reich (6) of the image sensor (5) (see. Fig. 4) in the presence of another type of precipitation (4) on the outside (2.2) of the windshield (2), namely Sneezing or drizzle.
• another type of precipitation (4) on the outside (2.2) of the windshield (2), namely Sneezing or drizzle.
• streaks (11) are present, which are recognized as such by the evaluation of the reflex structure. If drizzling area on is present on the outside of the pane (2.2), streaks are present on all corresponding illumination reflections (9).
• Fig. 5a the described is illustrated schematically, while in Fig. 5b, the described is shown on ei ⁇ nes real photos.
• FIGS. 1-3 schematically shows a part of the beam paths (cf., FIGS. 1-3) in the presence of a fitting (12) on the inner side (2.1) of the disk (2).
• the BL LEVEL ⁇ tung reflex (8) appears to be blurred on the inside of Schei ⁇ be mirrored partial beam (rl) appears.
• the Spiegelbil ⁇ the light source (3 ⁇ ) and the light beam (h A ) are shown schematically by dashed lines.
• FIG. 7a schematically illustrates what has just been described
• FIG. 7b illustrates the description on the basis of a real photo.
• r2 ⁇ corresponds to r2 in the rain on the outside of the window
• t2 ⁇ corresponds to t2 in rain on the outside of the window

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Mechanical Engineering (AREA)
• Automation & Control Theory (AREA)
• Multimedia (AREA)
• Theoretical Computer Science (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)

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• 2012
  • 2012-05-03 DE DE102012103873A patent/DE102012103873A1/de not_active Withdrawn
• 2013
  • 2013-04-26 JP JP2015509310A patent/JP6333238B2/ja not_active Expired - Fee Related
  • 2013-04-26 US US14/379,396 patent/US9702818B2/en not_active Expired - Fee Related
  • 2013-04-26 WO PCT/DE2013/100155 patent/WO2013163991A1/de not_active Ceased
  • 2013-04-26 EP EP13720769.2A patent/EP2844529A1/de not_active Withdrawn
  • 2013-04-26 DE DE112013002303.2T patent/DE112013002303A5/de not_active Withdrawn

Non-Patent Citations (1)

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