DE102017221262B3 - A method for detecting an object between a door frame and a door leaf of an open door and door security device - Google Patents

Abstract

For detecting an object (39) between a door frame (3) and a door leaf (2) of an opened door, first an image of a light band (13a, 13b), which is arranged on the door frame (3) or the door leaf (2), detected with a spatially resolving light sensor, which is correspondingly arranged on the door leaf (2) or the door frame (3). The light band image (13a, 13b) is parameterized, wherein each intensity value of the light emitted from the light band, a band coordinate of a light band location is assigned. Along at least selected one of the band coordinates, the intensity values are evaluated for at least two points in time. Band co-ordinates belonging to intensity values smaller than a predetermined minimum value are buffered as interruption hypothesis coordinates of an interruption by the object (39) which is possible at this time and assigned to the respective evaluation instants. According to a corresponding comparison, those hypothesis coordinates assigned to both evaluation times are buffered as interruption coordinate candidates. This is repeated, discarding interruption coordinate candidates that do not validate as hypothesis coordinates. As far as at least one interruption coordinate candidate is present after the repetitions, a corresponding signal is output. This results in a reliable detection of a door interruption.

Description

The invention relates to a method for detecting an object between a door frame and a door leaf of an open door. Furthermore, the invention relates to a door safety device including an evaluation circuit, which executes such a detection method and a door with such a door safety device.

Door safety devices that are to serve as a pinch protection, for example, as essay tapes, which in particular on the band side to prevent interference, and as Aufsteckelemente which are intended to prevent a closing of the door known.

The US 5,410,149 A discloses a detector for detecting an obstacle in the region of a door. Corresponding detection devices are known from the WO 2004/078 552 A1 , the DE 10 2014 113 572 A1 and the EP 1 700 763 A2 ,

It is an object of the present invention to provide a method for securely detecting a door interruption, that is, an interruption in a door closing area.

This object is achieved by a detection method with the features specified in claim 1.

According to the invention, it has been recognized that with the aid of a light sensor embodied as a camera, for example, at least one band-shaped light source, ie a light band, can be detected and the recorded image data of the light bands can be evaluated in such a way that secure detection of an object between the door frame and the door leaf, ie a secure interruption detection is ensured. A secure anti-trap is given by. By the evaluation circuit can then be safely prevented, for example, a door closing. When the light band image is parameterized, the association between the respective intensity values and the band coordinates can be carried out in such a way that the intensity value of the light emanating from the location of this band coordinate is assigned to each band coordinate. The at least one light band can have discrete light sources, which are homogenized via a corresponding homogenization to a light source continuously emitting light source.

In the case of a failure of a discrete light source, a position of the failed discrete light source can be marked accordingly during image acquisition, so that there is no unwanted signal output. Such a marking can be done on the software side by specifying appropriate masks. In this way, a distinction between failed single light sources on the one hand and an actual interruption on the other hand can be made. Alternatively, it is also possible to react to the failure of a discrete light source with a corresponding error message. As far as discrete light sources are used, this redundant light sources can be used, so that the failure of individual discrete light sources is not undesirable importance.

An additional mechanical cover band side can be omitted. Also final safety elements, which could also prevent a deliberate door closing omitted. The evaluation circuit can be designed so that a detection of light sensor signals only during a closing movement, ie during a pivoting of the door leaf from the open to the closed position, takes place. This can be done by evaluating signals of a door leaf drive control, if a door leaf drive is present. Alternatively or additionally, the door leaf pivoting and in particular a direction of the door leaf pivoting can be detected in particular optically with a pivot angle measuring device. The arrangement of the at least one light source on the one hand and the at least one light sensor on the other hand can be such that an optical path between the door leaf and the door frame along an entire course of the door frame so the circuit side, band side and stock side can be monitored. Alternatively or additionally, the arrangement may also be such that complete monitoring on the threshold side is possible, for example by accommodating at least one light source or at least one light sensor of the door safety device in the threshold region of the door and by correspondingly at least one light sensor or sensor in the threshold-side region of the door leaf at least one light source of the door safety device is housed.

A signal connection between components of the door security device can be wired and / or can be wireless.

The open door may be an at least partially open door. The captured image of the light band can still be computationally processed, z. B. be rotated. Such a rotation can take place such that each image line after rotation cuts the at least one light band exactly once. Part of an image processing can be the cutting out of a region of interest (ROI) of interest.

An angle sensor or a measuring device according to claim 2 can be designed as an optical sensor or as a potentiometer.

By including the door opening angle, a predetermined ROI can be precisely selected in the entire detection range of the light sensor according to claim 3, which reduces an evaluation effort of the light band image.

An adaptation of a light band course according to claim 4 can take place as a fitting of the hypothetical light band course to a predetermined by means of an analytical function band-light curve, for example as a circular segment fitting. This increases the robustness of the detection method with respect to extraneous light sources. The extended light band course can be predetermined, for example, on the basis of a known arrangement of the at least one light band as well as due to a likewise known distortion by an imaging optics of the light sensor. The fitting can be done using a RANSAC algorithm. For details of the RANSAC method, reference is made to the article "Random Sample Consensus: A Paradigm for Model Fitting with Applications to Image Analysis and Automated Cartography by Martin A. Fischler and Robert C. Bolles, 1981 and to the textbook by T. Strutz: Data Fitting and Uncertainty (2nd edition, Springer Vieweg 2016, ISBN 978-3-11455-8).

A sorting step according to claim 5 simplifies the evaluation of the intensity values. The sorting can take place with regard to a spatial coordinate or also with regard to a running index, for example the sequence of individual light sources along the light band.

The use of rectangle sets according to claim 6 has been proven in the evaluation.

Exclusion of shadowed band image areas according to claim 7 avoids unnecessary computational effort as well as an interrupt misallocation. An identification of shaded light band image areas can be made dependent on a door opening angle, in particular depending on a measured door opening angle. The identification of shaded light band image areas can be done by filtering. For filtering, pixel masks can be used, which are laid over an entire image capture area of the light sensor. In particular, image pixel rectangular quantities can be filtered.

An alternating control of light source groups according to claim 8 enables a lock-in detection method. A synchronization of the detection with the alternating drive frequency can take place.

The advantages of a door safety device according to claim 9 correspond to those which has already been explained above with reference to the erfmdungsgemäße detection method.

An opening angle measuring device according to claim 10 has the advantages that have already been explained above in connection with claim 2.

The advantages of a door according to claim 11 correspond to those which have already been explained above in connection with the detection method and with the door safety device. The door safety device can be designed as a retrofit kit for an existing door.

• 1 schematisch eine perspektivische Ansicht einer Tür mit einer Tür-Sicherheitsvorrichtung, die als Einklemmschutz wirkt;
• 2 ebenfalls schematisch und perspektivisch eine Türzarge der Tür mit mehreren Lichtquellen der Tür-Sicherheitsvorrichtung in Form von LED-Lichtbändern;
• 3 eine Aufsicht auf die Tür, wobei die Türzarge wand- und schlussseitig im Querschnitt dargestellt ist;
• 4 ein Segment eines der LED-Lichtbänder der Tür-Sicherheitsvorrichtung;
• 5 schematisch einen Abschnitt eines Türblatts einer Ausführung der Tür mit einem Klemmschutzkörper, der gleichzeitig als Spiegelkörper zur Erfassung abgeschatteter Lichtwege ausgeführt ist;
• 6 gesehen in einer zur 5 ähnlichen Perspektive eine weitere Ausführung eines Klemmschutzkörpers, wobei Abschlusskanten des Türblatts gestrichelt angedeutet sind;
• 7 eine Aufsicht auf den Klemmschutzkörper in einer Neutralstellung, gesehen aus Blickrichtung VII in 6;
• 8 in einer zur 7 ähnlichen Aufsicht den Klemmschutzkörper in einer Klemmschutzstellung;
• 9 ein Kamerabild eines als Kamera ausgeführten Lichtsensors der Tür-Sicherheitsvorrichtung, aufgenommen in einer Überwachungs-Zwischenschließstellung des Türblatts nahe der Schließstellung;
• 10 schematisch einen aus dem Bild nach 9 ausgeschnittenen, interessierenden Bildbereich (region of interest, ROI);
• 11 einen weiteren Details zeigenden Ausschnitt XI aus 10;
• 12 einen zusätzliche Details zeigenden Ausschnitt XII aus 11;
• 13 in einer zu 10 ähnlichen Darstellung die ROI nach 10 nach Abarbeiten eines Erfassungsschritts, welcher als Rechtecke dargestellte Hypothesen-Koordinaten einer möglichen Unterbrechung dargestellter Lichtband-Bilder durch einen Gegenstand zwischen der Türzarge und dem Türblatt zeigen;
• 14 schematisch einen Pixel-Weg zur Verfolgung eines vorab als Kreissegment angepassten hypothetischen Lichtband-Verlaufes im Rahmen der Auswertung von Bild-Intensitätswerten zur Bestimmung von Unterbrechungs-Hypothesen-Koordinaten;
• 15 Bilder von einem der Lichtbänder einer weiteren Ausführung mit alternierend leuchtenden geradzahligen und ungeradzahligen LEDs, aufgenommen zu drei aufeinander folgenden Zeitpunkten während einer Schließbewegung des Türblatts relativ zur Türzarge; und
• 16 ein Diagramm zur Verdeutlichung eines zeitlichen Verlaufs einer Sichtbarkeit (Erfassungs-Lichtintensität größer als Mindestwert) von LED-Lichtband-Koordinaten (Hochachse) über die Zeit (Querachse) zur Veranschaulichung einer erfassten Abschattung.

An embodiment of the invention will be explained in more detail with reference to the drawing. In this show:

• 1 schematically a perspective view of a door with a door safety device, which acts as anti-trap;
• 2 also schematically and perspectively a door frame of the door with multiple light sources of the door safety device in the form of LED light strips;
• 3 a plan view of the door, the door frame is shown on the wall and end side in cross section;
• 4 a segment of one of the LED fascias of the door security device;
• 5 schematically a portion of a door leaf of an embodiment of the door with a anti-jamming body, which is carried out simultaneously as a mirror body for detecting shaded light paths;
• 6 seen in a to 5 similar perspective, a further embodiment of a clamp protection body, wherein the end edges of the door panel are indicated by dashed lines;
• 7 a plan view of the anti-jamming body in a neutral position, seen from the direction of view VII in 6 ;
• 8th in a to 7 similar supervision the anti-jamming body in a terminal protection position;
• 9 a camera image of a camera safety sensor of the door safety device, taken in a monitoring Zwischenschließstellung of the door leaf near the closed position;
• 10 schematically one from the picture after 9 cut-out region of interest (ROI) of interest;
• 11 a detail showing detail XI out 10 ;
• 12 an additional detail showing section XII out 11 ;
• 13 in one too 10 similar representation after the ROI 10 upon completion of a detection step, which displays hypothesized coordinates of a possible break in displayed light-band images through an object between the door frame and the door panel;
• 14 schematically a pixel path for tracking a previously adapted as a circle segment hypothetical band-light curve in the context of the evaluation of image intensity values for the determination of interruption hypothesis coordinates;
• 15 Images of one of the light bands of a further embodiment with alternating bright even and odd LEDs, taken at three consecutive times during a closing movement of the door leaf relative to the door frame; and
• 16 a diagram illustrating a time course of visibility (detection light intensity greater than minimum value) of LED light band coordinates (vertical axis) over time (transverse axis) to illustrate a detected shading.

A door safety device is part of a door 1 with a door leaf 2 and a door frame 3 , The arrangement of a door lock 4 and door hinges 5 (see. 3 ) define a final page 6 and a band side 7 the door 1 , Further, the door has 1 an upper floor side 8th and a lower threshold side 9 ,

The door leaf 2 is between an open position and one in the 1 shown closed position pivotally. This pivoting is powered by a door leaf drive 10 which is part of the door security device. The door leaf drive 10 is in the door leaf 2 integrated.

3 shows the door leaf 2 in a monitoring intermediate closing position between the open position and the closed position of the door leaf 2 , The monitoring intermediate closing position is in a subsequent to the closed position door leaf pivot angle range of at most 25% of an entire door leaf pivot angle between the open position and the closed position. In the illustrated embodiment according to 3 is the monitoring intermediate closing position at a door leaf pivot angle of about 10 °, starting from the closed position before. With a total door leaf swing angle of 180 ° between the open position and the closed position, this corresponds to a door leaf swing angle range of about 5% (1:18) of the entire door leaf swing angle. Another door leaf pivot angle range in the range, for example, of 10%, 15%, 20% or 25% of the total door leaf pivot angle is possible. In absolute terms, the monitoring intermediate closing position may be present at a door leaf pivot angle of at least 3 °, at least 4 °, at least 5 °, at least 7 °, at least 10 °, at least 15 ° or at least 20 °. The maximum door leaf swing angle of the inter-surveillance interlocking position may not exceed 20 °, not more than 15 °, not more than 12 ° or not more than 10 °.

The door safety device further includes at least one light source. In the illustrated embodiment, the light source is formed as a plurality of light bands 11 . 12 . 13 . 14 , The light bands 11 and 14 are in the band side 7 on the door frame 3 arranged. The light band 12 is in the area of the floor side 8th on the door frame 3 arranged. The light band 13 is in the area of the final page 6 on the door frame 3 arranged.

3 clarifies the arrangement of the two light bands 11 and 14 in the band side 7 the door frame 3 , The light band 11 is the opening side and the light band 14 at the end of the band side 7 on the door frame 3 appropriate. Accordingly, the closing side light band 13 also be divided into an opening-sided light band 13a and a closing light band 13b , like in the 3 shown.

4 shows a segment of one of the light bands 11 to 14 using the example of the light band 11 , The light band 11 has lined up along its extension in a first row a plurality of VIS LEDs 15 that emit visible light. These may be white light LEDs and / or RGB LEDs. In particular, it may be LEDs whose emitted VIS wavelength can be changed by appropriate control between red, green and blue. In a second row contains the light band 11 a plurality of stringed IR LEDs 16 , The light band 11 can be considered a plurality of light band segments 17 be executed. Schematically represented in the 4 also still contact pins 18 for power supply and control of the LEDs 15 . 16 , The light bands 11 to 14 carry a diffuser layer for diffuse distribution of the light emitted by the discrete LEDs. This diffuser layer can be designed as a plastic layer. The effect of the diffuser layer is such that along the respective light bands 11 to 14 a consistently within specified tolerance limits equal intensity of the LED light is emitted.

The door safety device further comprises an evaluation circuit 19 in the 1 is shown schematically. The evaluation circuit 19 is in signal communication with the door leaf drive 10 which represents a safety device of the door safety device. The safety device 10 Used to prevent the door closing depending on the control by the evaluation circuit 19 ,

The evaluation circuit 19 is also in signal communication with the light source, so with the light bands 11 to 14 ,

Furthermore, the door safety device comprises at least one light sensor 20 , The light sensor 20 is designed as a camera and especially as a fisheye camera with all-round 180 degree detection range. The detection range of the light sensor 20 may be greater than 180 ° and may be for example 190 °, 185 ° or 183 °. Alternatively or additionally, a photodiode, a sensor line, a sensor array or a CCD is possible as a light sensor.

The evaluation circuit 19 is used to evaluate the presence of a light path interruption between the light source 11 to 14 and the light sensor 20 , Part of the evaluation circuit 19 is a control device 19a ,

Such as the 3 can be taken, are the light bands 11 . 13 . 14 on the one hand and the light sensor 20 on the other hand so on the door leaf 2 on the one hand and on the door frame 3 on the other hand arranged, at least in the monitoring Zwischenschließstellung after 3 a light path (see exemplary light rays 21 in the 3 ) between the light source 11 to 14 and the light sensor 20 from an external object 22 , the Indian 3 indicated by dashed lines, between the door leaf 2 and the door frame 3 is interruptible. A corresponding interruption of the light path is provided by the light sensor 20 detected and from the evaluation circuit 19 recognized. In accordance with the present subject 22 between the door leaf 2 and the door frame 3 controls the evaluation circuit 19 the door leaf drive 10 so on, that the door leaf drive 10 is stopped and closing the door panel 2 is prevented. As a result, an anti-trap protection is effectively realized.

The camera 20 is central on a door leaf closing side 23 arranged.

Based on 5 to 8th Further embodiments of a door leaf of a door safety device will be explained. Components which correspond to those described above with reference to 1 to 4 already described, bear the same reference numbers and will not be discussed again in detail.

The door leaf 2 to 5 has a clamp protection body 25 on, which is also designed as a mirror body, which will be explained below. The anti-jamming body 25 is displaceable between a neutral position (see 6 and 7 ), in which the door leaf 2 relative to the door frame 3 can reach the closed position, and a terminal protection position (see 5 and 8th ), in which a moving of the door leaf 2 is prevented from the open position or monitoring intermediate position in the closed position. In the terminal protection position of the anti-jamming body 25 So an anti-trap is guaranteed. In the neutral position is the anti-jamming body 25 in the door leaf 2 sunk. A shift of the anti-pinch body 25 between the neutral position and the clamping position is guided on both sides of the clamp protection body mounted guide rails 26 ,

On its upper side carries the anti-jamming body 25 a driver designed as a tongue 27 , which in the terminal protection position vertically in a rebate area of the door leaf 2 protrudes. As far as the anti-jamming body 25 is unlocked in the terminal protection position, which causes the driver 27 when closing the door leaf 2 entraining door frame 3 the displacement of the anti-pinch body 25 from the terminal protection position to the neutral position. The driver 27 is in a guide recess 27a in the rebate area of the door leaf 2 guided.

An underside of the anti-pinch body 25 carries a mirror element 28 , The latter can be used as a polished surface of, for example, metallic anti-pinch body 25 or alternatively as a reflective coating or as a separate and with the other anti-jam body 25 be executed connected mirror element. The mirror body 28 can be designed as a planner or as a curved mirror. The curved mirror design allows imaging of a relevant higher resolution surveillance area.

Schematically are in the 5 two variants of light paths 29 . 30 emitted LED lights represented by the same section of the in the 5 not shown, end-side light band 13 the door frame 3 out. The light path 29 is a direct light path between this section of the light band 13 and the light sensor 20 , This light path 29 is at least partially from a door handle 31 of the door leaf 2 shadowed. What direct light paths between the end-side light band 13 and the camera 20 So, there are about one in the 5 indicated blind spot range α shading of the LED light, the in any case, in certain monitoring intermediate positions prevent monitoring of another light path interruption.

Such blind spots are due to the anti-jamming body also designed as a mirror body 25 avoided. The alternative light path 30 in the 5 goes from the same section of the end-side light band 13 in the same assumed monitoring intermediate position and runs from this section of the light band 13 , reflected by the mirror element 28 without shading to the light sensor 20 , The mirror body 25 So makes light paths between the light source of the door security device and the light sensor 20 by reflection on the mirror body 25 accessible, which are shadowed on a direct route due to door components at least in a certain intermediate monitoring position.

6 shows a variant of the anti-jamming body 25 instead of a narrow driver 27 whose extension in the 6 For comparison, again indicated by dashed lines, the anti-jamming body has 25 to 6 a over the entire width of the anti-jamming body 25 extending driver 32 whose function otherwise that of the driver 27 equivalent.

The anti-jamming body 25 to 6 has in a section of the guide rail 26 an opening 33 for locking the anti-pinch body 25 in the neutral position. This locking is a locking device 34 in the form of two mutually on both sides of the anti-pinch body 25 arranged magnetic bolt 34a . 34b ,

The magnet bolts 34a . 34b are in the 7 shown in a neutral position in which the magnet bolts 34a . 34b not with the clamp body 25 interact. About locking drives 35a . 35b in the door leaf 2 are arranged sunk, the magnet bolts can 34a . 34b between in the 7 illustrated neutral or release position and one in the 8th be shifted shown locking position. Instead of a magnetic locking drive 35 may be a locking device on the type of magnetic bolts 34a . 34b and the lock drives 35a . 35b also not be designed magnetically, for example via at least one locking bolt, which is motor-driven, for example by a servomotor.

In addition to the drawing not shown locking position in which the magnetic bolt 34a . 34b in the associated openings 33 engage and the clamp body 25 fix in the neutral position, is in the locking position of the magnetic bolt 34a . 34b the terminal protection position of the anti-jamming body 25 fixable, as in the 8th shown. The magnet bolts 34a . 34b are disengaged in the locked position and block by being on a back wall 36 of the anti-jamming body 25 strike, a return of the anti-jamming body 25 from the terminal protection position to the neutral position.

About a biasing device 37 is the anti-jamming body 25 biased in the terminal protection position. The pretensioner 37 has two biasing springs designed as compression springs 37a . 37b , on the one hand, against the door leaf 2 and on the other hand against the anti-pinch body 25 support. This can be done in the door leaf 2 and / or in the anti-pinch body 25 corresponding blind holes for the bias springs 37a . 37b be provided.

The locking drive 35 can be designed and controlled so that the locking device 34 is positioned in the locking position with inactive locking drive, in which the anti-jamming body 25 locked in the terminal protection position. The locking drive 35 stands with the evaluation circuit 19 in signal connection.

As far as the mirror element 28 Part of the anti-pinch body 25 is, is the mirror element 28 only active when the anti-jamming body 25 present in the terminal protection position. Alternatively, the then independent mirror body 25 with the mirror element 28 be executed so that it has no anti-trap function and constantly ensures monitoring shaded light strip sections. Again, alternatively, the mirror body 25 through interaction of the door leaf 2 with the door frame 3 from a mirror position accordingly 5 and a lowered neutral position, but have no anti-pinch function.

The door 1 still has a measuring device 38 (see. 1 ) for measuring an opening or pivoting angle of the door leaf 2 relative to the door frame 3 in the respective monitoring intermediate position. The measuring device 38 can be designed as a potentiometer, making the swivel angle measurement accessible via a resistance measurement. Alternatively, an optical tilt angle measuring device 38 be provided, for example, an optical incremental encoder.

The door safety device with the components 11 to 14 . 20 . 19 and optionally 10 or with the other components described above may be designed as a retrofit kit for an existing door. As far as a door leaf drive on the type of door leaf drive 10 is present in such, already existing door, the door safety device may be designed so that it uses the existing door leaf drive.

For detecting an object, eg. B. a finger 39 (see. 9 ) one person 40 , between the door frame 3 with the final light bands 13a . 13b and the door leaf 2 The open door is operated as follows:

First, the light bands 11 to 14 as far as they are within the detection range of the camera 20 lie, with this captured. 9 shows an example of the camera 20 captured image in a monitoring intermediate position near the closed position of the door leaf 2 , Due to a fisheye look of the camera 20 The picture appears distorted and circular. The picture example after 9 shows pictures of the two final light bands 13a . 13b as well as the band-side light band 14 , The stock-sided light band is through an edge of the door frame 3 in the area of the floor side 8th just hidden.

After the image has been acquired, it can still be computationally processed and, in particular, rotated. This rotation of the image takes place until every horizontal image line (cf. 9 exemplary section-wise drawn horizontal picture lines 41 ) after the rotation, the final and band side light bands 13a . 13b . 11 and 14 as far as recorded, cuts exactly once. The image processing following the acquisition may be a cutting out of a region of interest (ROI) of interest.

10 schematically shows one within a total rectangular total detection area 42 the camera selected ROI 43 , Unselected areas of the total coverage 42 are shown hatched. The transition between these non-selected areas and the ROI 43 is in the 10 through dashed ROI boundaries 44 clarified. The selection of the ROI 43 takes place dynamically depending on a door opening angle, by the measuring device 38 is measured, and controlled by the control device 19a the evaluation circuit 19 , The subsequent image evaluation is done exclusively using the image data within the ROI 43 , that is, using the pixel-by-pixel detected light intensity values. An xy coordinate system of the total coverage area 42 is in the 10 also marked. The x-coordinate represents the horizontal coordinate and the y-coordinate represents the vertical coordinate.

The ROI 43 contains the pictures of the final light bands 13a . 13b , These light band pictures 13a . 13b are parameterized so that a sequence of intensity values of a detected light intensity along the light band results. Each band coordinate of a light band location is assigned an intensity value. This intensity value is detected starting from the respective light band location. Mask parameters of the ROI selection, ie the course of the ROI boundaries 44 , can be determined by polynomial regression. For this, a teach-in method can be used when performing the detection method several times, so that the ROI is made as small as possible, depending on the measured door opening angle, but as large as necessary for the correct object detection. The ROI 43 is in the considered embodiment always so large that the entire, originally recorded light bands 13a . 13b are included.

When parameterizing the light band images 13a . 13b For the subsequent evaluation in the object detection, an adaptation of a light-band course hypothetical on the basis of the detected intensity values to an expected light-band course takes place. The expected light band course is in the illustrated embodiment due to the fisheye optics of the camera 20 a circle segment. With this adaptation, a RANSAC algorithm can be used. The result of this parameterization are two circular segment hypotheses C _r and C ₁ in the 10 are shown in phantom and their course according to the goal of adaptation to that of the images of the light bands 13a . 13b equivalent. These circle segment hypotheses C _r and C ₁ , are each determined by a district center Z whose position in the x / y coordinates of the coordinate system of the total detection area 42 is specified, as well as by a radius R of the circle segment.

About the position of the detected circle segment hypotheses C or C _r . C ₁ can be closed directly to the door opening angle in a variant of the detection method, so that in this case an additional measuring device on the type of measuring device 38 eliminated.

When performing the RANSAC fitting procedure in the determination of circular segment hypotheses C _r . C ₁ pixels are determined which are closer than a predetermined tolerance distance to the calculated circle segments. These pixels are also referred to as "inlier". The pixel set of "inlier" for the circular segment hypotheses C _r . C ₁ are also referred to as a consensus set.

Instead of the RANSAC fitting algorithm, another fitting algorithm can also be used, for example a least square algorithm.

To determine the initially hypothetical band of light curve based on the detected intensity values are first starting from the right ROI boundary 44 _r by pixel-by-pixel scanning along the respective horizontal image line 41 those pixels searched whose Intensity exceeds a minimum or threshold. The minimum intensity level can be adjusted by pre-calibrating the light sources 15 _i be determined. For example, this may be half of a maximum intensity value found during the calibration. A ratio between the minimum value and the maximum value may range between 0.05 and 0.95.

Scanning lines along which x-values corresponding to certain y-values are determined by the given minimum intensity value-exceeding hypothesis pixels are shown in FIG 11 at 45 located.

12 shows such a scan line 45 in an extreme zoom, the single pixels 46 the ROI 43 dissolves. By differently dense hatching on the pixels 46 are the measured intensity values of these pixels 46 illustrated. With an "x" are those pixels 46 along the scan line 45 illustrates whose intensity value is above the threshold. In the example shown, these are four "x" pixels. The associated x-coordinate, which is the y-coordinate of this scan line 45 belongs to the hypothetical band-light course, is determined by arithmetic mean value formation of the x-coordinates of these "x" pixels 46 calculated.

This detection of the hypothetical light band course can be done over a predetermined number of scan lines spaced apart in the y-direction 45 done as in the 11 and 13 indicated, and give the output data for the subsequent (RANSAC) fitting of the circle segments.

The detection along the respective scan line 45 can be aborted prematurely if two intensity maxima were found. The detection along the scan line 45 breaks at the latest when the left ROI limit is reached 44 ₁ from. The respectively detected intensity maximum becomes the right light band 13a and the second detected intensity maximum to the left light band 13b assigned.

The intensity values of the in-pixels 46 are then evaluated along at least one selected section of the light bands 13a . 13b , ie along at least selected band coordinates of the light bands 13a . 13b , This evaluation first takes place at a first time t = t ₀ . Band coordinates of the light bands 13a . 13b , which belong to intensity values that are smaller than a predetermined minimum intensity value, in this evaluation as a hypothesis coordinates one at this time t ₀ possible interruption by an object between the door frame 3 and the door leaf 2 cached and at the first time t ₀ assigned.

Within the scope of the registration procedure, this evaluation step therefore becomes interrupted 47 in the pictures of the light bands 13a . 13b along the connecting lines between successive points of the consensus sets along the ascertained circular segment hypotheses C _r . C ₁ searched. As such interruptions 47 become pixels (see the example in the 14 represented pixels 46 ) on these circle segment hypotheses C _r . C ₁ whose intensity values are smaller than a minimum intensity value. For a ratio between this minimum intensity value and a maximum intensity value, what has been stated above for the minimum intensity value used for determining the hypothetical light band profile applies, wherein these two minimum intensity values do not have to match.

Found interruptions 47 are written by these enclosing rectangles (cf. 13 ). The result of this evaluation step is a set of hypothesis coordinates one at a time t ₀ possible interruption 47 represented by a corresponding set of rectangles in the ROI 43 , The enclosing rectangle is in the 13 at 48 specified.

In this evaluation along the light-band coordinates, the in-pixels identified by their x / y coordinates become 46 sorted on the basis of their successive, ie increasing or decreasing y-coordinates. For every two consecutive in-point points with respect to their y-coordinate P ₁ . P ₂ In addition, if available, those pixels 46 in terms of their intensity values, on the connecting line between these inlier points P ₁ . P ₂ lie (cf. 14 ).

Such a pixel-accurate sampling with inclusion of the intermediate pixels between the in-pixels P ₁ . P ₂ can be done using the Bresenham algorithm. Once an intensity value of one of the considered pixels 46 is below a minimum intensity value (threshold, default value), this pixel becomes 46 as an interruption 47 of the respective light band 13a . 13b scored. Details of the Bresenham algorithm can be found in JE Bresenham: Algorithm for computer control of a digital plotter, IBM Systems Journal, 4, 1, 1965, pages 25 to 30, ISSN 0018-8670 and in R. Plontje: LION-LV1: A Lithograhie System for Integrated Optics and Nanostructures, Jenaer Jahrbuch zur Technik- und Industriegeschichte, Volume 9, 2006, pp. 535 to 566.

As part of the detection process, light band image areas can be identified that are from door components, such as the door handle 31 to be shaded. The respective identified, shaded by door components band of light image areas then do not go into the other Evaluation for detecting an object between the door frame 3 and the door leaf 2 on. An appropriate shading area 49 of the light band 13a due to the door handle 31 is in the 9 specified. A corresponding pixel mask due to door component shading can be measured dynamically on the basis of the respective door opening angle, measured via the measuring device 38 , from the controller 19a be specified. Such shading area 49 , For example, the door handle 31 , can also be specified by a static pixel mask regardless of a door opening angle. On such a door component shading can, at least partially, be waived, if shaded areas by using the mirror body 25 the measurement can still be made available, as above, for example, with reference to 5 explained.

The evaluation of the intensity values along the consensus set of the inlier points P _i or the in-pixel 46 is repeated at further, later times t ₁ ... t _N , Also in the evaluation at these later times t _i ( _i = 1 ... _N ), band coordinates belonging to intensity values smaller than a predetermined intensity minimum value become hypothesis coordinates of one at that time t _i possible interruption by an object between the door frame 3 and the door leaf 2 later t _i assigned.

Anytime t _i then become the sets of rectangles 48 the interruptions 47 and buffering the hypotheses coordinates associated with the respective times at least two times as interruption coordinate candidates. When comparing the amount of break rectangles 48 For example, changes in the y-coordinate with respect to the likelihood that it is not an actual break are weighted more heavily than movements along the x-coordinate, since such movements are along the x-coordinate due to the movement of the door leaf 2 relative to the door frame 3 are to be expected.

The evaluation steps are for a certain number of times t _i For example, for two, three, four, five, or even more times t _i repeated. Interrupt coordinate candidates are discarded that do not confirm as hypothesis coordinates at least one time. If, after these repetitions of the evaluation step, at least one candidate for interruption is still present, the evaluation circuit outputs 19 a signal "object between door frame 3 and door leaf 2 recorded ". The control device 19a then can the door leaf drive 10 stop or a closing mechanism for the door leaf 2 brake.

The individual light sources of the light bands 11 to 14 , That is, the LEDs, may be so controlled that alternately a first light source group and a second light source group lights, wherein apart from the light band ends in each case a light source of the first light source group between two light sources of the second light source group. This embodiment is described below with reference to 15 and 16 explained in more detail.

15 shows the picture of a light band using the example of the light band 13a at three consecutive times t ₀ . t ₁ and t ₂ , Shown in the 15 schematically the IR LEDs and / or VIS LEDs 15 of the light band 13a at the respective time t _i to shine. At the time t ₀ light up, starting with the in the 15 LED at the bottom, the odd-numbered LEDs corresponding to those in the 15 With 15 ₁ . 15 ₃ , ... 15 _{2n + 1} are designated. At the following time t ₁ On the one hand, the light band image has moved in the negative x-direction and, on the other hand, the even-numbered LEDs now light up due to the alternating activation of the light source group 15 ₂ . 15 ₄ , ... 15 _2n , For the subsequent time t ₂ has the light band image 13a continues to move in the negative x-direction and the odd-numbered LEDs shine 15 ₁ . 15 ₃ , ... 15 _{2n + 1} ._

About a point filter can be in the total coverage 42 the camera 20 the respective illuminated LEDs 15 _i capture as glowing points. A corresponding image processing can then the x / y coordinates and the radius of the corresponding circular segment hypotheses C determine. This can be a lock-in detection method, which with the Alternierungs-Ansteuerfrequenz the two light source groups 15 ₁ ... 15 _{2n + 1} on the one hand and 15 ₂ , ... 15 _2n on the other hand synchronized done. This achieves effective ambient light suppression.

The detected intensity values of the respective LEDs 15 _i can then be put into an i / t matrix (cf. 16 ), where i is the index of the respective LED 15 _i and t is the detection time.

The three in the matrix after 16 columns shown on the left correspond to the measurement times t ₀ . t ₁ . t ₂ , which are described above on the basis of 15 were explained. In the 16 is still a shading or interruption area 47 represented, which is present in a period between the times t ₃ > t ₂ and t ₄ > t ₃ . At a time t _max between times t ₃ and t ₄ is the extent of the interruption 47 along the detected light band 13a maximum. Such an interruption 47 can be seen from the fact that there due to the alternating control of even-numbered and odd-numbered LEDs resulting checkerboard pattern of intensity values in the time-band coordinate diagram after 16 is interrupted.

With the help of the detection based on alternately driven light source groups can be detected in addition to the interruption, whether ambient light outshines the respective light band, so if pixels are mistakenly detected as a bright light sources, although these belong straight to the non-luminous light source group. Also in the process after 16 After acquiring a camera image, a creation of a parameterized light band image takes place, such that a sequence of intensity values along the light band 13a and thereafter evaluating the intensity value along the bandgap coordinates, represented here by the index i at different times including comparing associated break hypotheses coordinates and validating breakpoint coordinates, according to what has been described above in connection with FIGS 9 to 14 has already been explained.

Instead of circular segments or partial circles, as described above on the basis of the fisheye optics, a segment hypothesis can also be based on another, in particular analytical function, for example on the basis of a polynomial fit.

Claims (11)

A method of detecting an object (39) between a door frame (3) and a door leaf (2) of an opened door (1), the door (1) comprising at least one belt-shaped light source (11 to 14), a light band arranged on a door component comprising the group of door frame (3) and door leaf (2) and at least one spatially resolving light sensor (20) arranged on the other door component of the group of door frame (3) and door leaf (2), comprising the following steps: a) capturing an image of the B) parameterizing the light band image (13a, 13b) such that a sequence of intensity values of a detected light intensity along the light band (13a, 13b) results, wherein each intensity value is a band coordinate (x, y, i) is associated with a location of the light band (13a) from which this intensity value was acquired, c) evaluating the intensity values along at least one of the band coordinates (x, y, i) to one first time point (t ₀ ,) where band co-ordinates belonging to intensity values which are smaller than a predefined minimum intensity value, as hypothesis coordinates of an interruption (47) possible at this time by an object (39) between the door frame (3) and the door panel (2) being latched and assigned to the first time (to); d) evaluating the intensity values along the selected band coordinates (x, y, i) at a later time (t ₁ ), wherein band coordinates belonging to intensity values include are smaller than predetermined minimum intensity values, again as hypothesis coordinates of an interruption (47) possible at this time by an object (39) between the door frame (3) and the door leaf (2) are cached and assigned to the later time, e) Comparing the hypothesis coordinates associated with the times (t ₀ , t ₁ ) and buffering at both times (t ₀ , t ₁ ) z f) repeating steps d) and e) for a predetermined number of repeats, discarding break coordinate candidates that do not confirm as hypothesis coordinates at least one time; g) so far after those repeats there is still at least one interruption coordinate candidate: outputting a signal "object detected between door frame and door leaf". Method according to Claim 1 , characterized in that in the evaluation of the intensity values is received via a angle sensor (38) detected door opening angle. Method according to Claim 2 , characterized in that depending on the door opening angle in the image acquisition, a detected image detail (43) of a total detectable image (42) is selected. Method according to one of Claims 1 to 3 , characterized in that when parameterizing the light band image (13a, 13b) takes place an adaptation of a due to the detected intensity values hypothetical band-light curve to an expected band-light curve (C _r , C ₁ ). Method according to one of Claims 1 to 4 , characterized in that, in evaluating the intensity values along the selected band coordinates (x, y, i), the band coordinates are sorted along a dimension (y, i), the intensity values of image pixels (46) between two successive band coordinates (y , i) are evaluated and compared with the predetermined minimum intensity value. Method according to Claim 5 , characterized in that directly adjacent image pixels (46), which were used in the context of the comparison and have an intensity value smaller than the predetermined minimum intensity value, detected by this image pixel (46) enclosing Rectangular sets (48) and further processed. Method according to one of Claims 1 to 6 characterized in that light band image areas (49) are shadowed by door components (31), the identified shadowed light band image areas (49) not being included in the further evaluation for detecting an object (39) between the door frame (Fig. 3) and the door leaf (2). Method according to one of Claims 1 to 7 , characterized in that the band-shaped light source (11 to 14) by a series of light sources (15 _i ) is realized, wherein the light sources (15 _i ) are driven so that alternately a first light source group (15 ₁ ... 15 _{2n + 1} ) and a second light source group (15 ₂ ,... 15 _2n ) illuminate, wherein, apart from the light band ends, a light source of the first light source group (15 ₁ ,... 15 _{2n + 1} ) is between two light sources of the second light source group ( ₂ , ... 15 _2n ). Door safety device for a door (1), - with at least one light source (11 to 14), - with at least one light sensor (20), - wherein the light source (11 to 14) and the light sensor (20) to each other on a door leaf (2) or a door frame (3) of the door (1) can be arranged that in at least one predetermined monitoring intermediate closing position of the pivotable between an open position and a closed position door leaf (2) relative to the door frame (3) an optical path between the light source (11 to 14) and the light sensor (20) of an external object (22) between the door leaf (2) and the door frame (3) is interruptible, - with an evaluation circuit (19) for evaluating the presence of a light path interruption, wherein the evaluation circuit (19) is in signal communication with the light sensor (20), - with a safety device (10) for preventing a door closing in the presence of the light path interruption, - wherein the evaluation circuit (19) in Sig is connected to the safety device (10), - wherein the evaluation circuit (19) is designed so that it is a method according to one of Claims 1 to 8th executing. Door security device behind Claim 9 , characterized by an opening angle measuring device (38) as an angle encoder for the door opening angle. Door (1) with a door safety device according to one of the Claims 9 or 10 ,

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