EP3724677A1

EP3724677A1 - 3-d sensor system having scene lighting that depends on a solid angle

Info

Publication number: EP3724677A1
Application number: EP18826220.8A
Authority: EP
Inventors: Urs Hunziker; Johannes Eckstein; Beat Wyss; Christian Seiler
Original assignee: Bircher Reglomat AG
Current assignee: Bircher Reglomat AG
Priority date: 2017-12-12
Filing date: 2018-12-11
Publication date: 2020-10-21
Also published as: DE102017129639A1; WO2019115559A1

Abstract

The invention relates to a sensor system (100) and to a method for three-dimensionally sensing a scene (190). The sensor system (100) comprises: (a) a lighting device (130) for lighting the scene (190) with illuminating light (131); (b) a measuring device (110) for receiving measurement light (196), which is illuminating light (131) at least partially backscattered by at least one object (195) contained in the scene, and for measuring distances between the sensor system (100) and the at least one object (195) on the basis of the light propagation time of the illuminating light (131) and of the measurement light (196); and (c) a data-processing device (150) connected downstream of the measuring device (110), for determining the three-dimensional characteristic of the scene (190) on the basis of the measured distances. The lighting device (130) is configured in such a way that a lighting intensity of the illuminating light (131) depends on the solid angle of the beam path of the illuminating light (131), such that a distance-based intensity loss of the illuminating light (131) and of the measurement light (196) is at least partially compensated. The invention further relates to different uses of a sensor system (100) of this type.

Description

3D sensor system with one dependent on a solid angle

scene lighting

Technical area

The present invention relates to a sensor system and a method for three-dimensional acquisition of a scene based on transit time measurements. Furthermore, the present invention relates to several uses of such

Sensor system.

Background of the invention

For opening and / or closing of openings are often by means of

Actuators operated closure body used, which facilitate the handling of the respective closure body for operators or automatically operated without any action, for example, when an object to be passed to the opening passes into the region of the opening. Such an opening may, for example, be a passageway in a building. A closure body may be, for example, a door or a gate.

To automatically open and close a high level of operational safety

To achieve closing closure bodies, it is known to detect the area in front of or within an opening which can be covered by a closing body by means of an optical sensor system. This can on the one hand ensure that when the opening is closed, it is not accidentally For example, a person is trapped by the closing body.

In addition, in some applications such a sensor system may cause automatic opening of the closure body or opening. In this context, it is also known that such a sensor system or a data processing device connected downstream of such a sensor system uses known methods of image processing

Performs object detection and releases the opening only if an authorized to pass the openings object in the range of (still

closed opening). Such object recognition can

for example, a face recognition.

From EP 2 453 252 B1, a 3D sensor system is known for the field of application of the monitoring of automatically opening doors and / or gates, which is based on the principle of transit time measurement of light beams emitted by illumination sources and after an at least partial reflection or 180 ° Backscatter be detected by a light receiver. Such sensor systems are commonly referred to as "time-of-flight" (TOF) sensor systems. However, TOF sensor systems have the disadvantage that with

increasing distance d of the object to be detected, the intensity of the (backscattered) measuring light to be detected by a light receiver of the TOF sensor is weakened in two respects. In the case of a punctiform illumination light source without a special focus, it scales

Attenuation of the illumination light emitted by the illumination sources with l / d ^/ 2, where d is the distance to the illumination light source. The same applies to the measurement light, if one a point of the object, at which the

Illumination light is scattered isotropically, perceived as a point light source. As a result, in this case, this leads to a l / d 'scaling of the intensity of the

received measuring light. In the case of beamforming realized in some manner, for example focusing, of the illumination light, of the measurement light and / or in the case of a non-isotropic scattering of the illumination light with a preferred emission of the measurement light in the direction of Light receiver, the intensity attenuation is correspondingly lower, but still contributes to a significant loss of light output. This in turn leads to a correspondingly poor energy efficiency of a TOF sensor system.

It is an object of the present invention to provide an energetically efficient and nevertheless reliable three-dimensional detection of a scene which also includes relatively distant objects.

Summary of the invention

This task is solved by the objects of the independent ones

Claims. Advantageous embodiments of the present invention are described in the dependent claims.

According to a first aspect of the invention, a sensor system for

Three-dimensional capture a scene described. The sensor system includes (a) a lighting device for illuminating the scene

Illumination light; (B) a measuring device (BL) for receiving measuring light, which is at least partially backscattered by at least one object contained in the scene illumination light, and (b2) for measuring

Distances between the sensor system and the at least one object based on a light transit time of the illumination light and the measurement light; and (c) data processing means connected downstream of the measuring device for determining the three-dimensional characteristic of the scene based on the measured distances. According to the invention, the illumination device is configured such that an illumination intensity of the illumination light depends on the solid angle of the beam path of the illumination light, so that a distance-based intensity loss of the illumination light and the measurement light is at least partially compensated. The described sensor system, which is a so-called Time Of Flight (TOF)

Sensor system is, it is based on the knowledge that by a variable in terms of intensity illumination of the scene to be detected optimal

Lighting can be achieved, which in the result leads to that of all sub-areas of the scene received measuring light in terms of its intensity is at least approximately equal. As a result, it can be avoided that there are underexposed and / or overexposed subregions of the measurement light in an image of the detected scene. The characteristic of the illumination light can thus be adjusted so that the intensity is always just as high as it is for a reliable detection of the respective solid angle range

associated portion of the scene is required. This will for the

Lighting only requires as much energy as is required, so that the described sensor system is characterized in the result by a good energy efficiency.

Depending on the use of the described sensor system, criteria for reliable detection over time or with the solid angle may vary. Thus, a particularly reliable detection in a region of the closing edge of a closing sliding door may be required and be ensured by a suitable illumination angle dependent on the illumination angle.

The term "illumination light" in this document means those electromagnetic waves which are emitted by a light source of the illumination device and strike the relevant object of the scene. The "measuring light" are the backscattered by or on the object electromagnetic waves, which from the measuring device or a

Received light receiver of the measuring device and for the three-dimensional evaluation of the scene, together with the corresponding TOF

Distance information, to be used. The term "scene" may in particular be understood to mean that spatial area which is optically detected by the sensor system. Objects in the scene are recognized by a suitable image analysis. For this purpose, the data processing device can make use of known methods for image evaluation and / or image analysis. The

Data processing device can therefore be a special

Be image processing processor and having one that is configured, known methods for image analysis and / or image processing

to apply or to carry out.

The term "object" can be understood as meaning any spatially physical structure which has a surface texture which leads to an at least partial reflection or scattering of illumination light and is therefore visible to the measuring device by the resulting measurement light. The object may be an object such as a motor vehicle or a living being such as a human. The object may be in relation to that

Sensor system be static or dormant object. Furthermore, the object may also move within, leave or enter the scene.

Through a repeated scene capture, the movement (according to the law of speed = distance / time) of the object can then be determined (by comparing the different spatial positions determined with different scene acquisitions). Depending on the application, the

Absolute value of the velocity and / or the motion vector, i. additionally the direction of movement, be determined.

The term "characteristic of a scene" can be understood as the entirety of all spatial structures which are detected by the sensor system. In this case, some structures can be recognized as being relevant and other structures as being less or even irrelevant by the data processing device by means of image processing and / or image recognition. The term "distance-based loss of intensity" can mean the one

Reducing the intensity of illumination light and measuring light are understood, which by an expansion of the cross section of the

Lighting light beams is caused. In the case of a point light source without a special focus, this loss scales with l / d ^, where d is the

Distance to the point light source is. The same applies to the measuring light when a point of the object at which the illumination light is scattered isotropically, as a point light source. As a result, this leads to a l / d 'scaling of the resulting measurement signal, which is given by the intensity of the received measurement light. In one way realized in any way

Beam shaping, for example, focusing, the illumination light, the measuring light and / or in a non-isotropic scattering of the illumination light with a preferred emission of the measuring light in the direction of

Measuring device, the "distance-based intensity loss" is correspondingly lower, but in practice still represents a significant loss, which reduces the energy efficiency of a TOF sensor. According to the invention, these losses are at least partially reduced or compensated by a suitable room-angle-dependent intensity of the illumination light.

The terms "optical" and / or "light" may refer to electromagnetic waves having a particular wavelength or frequency or a particular spectrum of wavelengths or frequencies. In particular, the electromagnetic waves used can be assigned to the spectral range visible to the human eye. Alternatively or in combination, electromagnetic waves associated with the ultraviolet (UV) or infrared (IR) spectral regions may also be used. The IR spectral range can extend into the long-wave IR range with wavelengths between 3.5 pm to 15 pm, which are determined by means of the

Light receiver of the sensor can be detected.

It should be noted that the inventive compensation of Distance-based intensity loss by means of the space angle-dependent

Intensity distribution of the illumination light is not only possible for TOF sensor systems that illuminate the whole or at least larger portions of the scene simultaneously. The compensation according to the invention can also profitably be used in TOF sensor systems, which scan the scene sequentially with an illumination light beam, for example a laser beam.

According to one exemplary embodiment of the invention, the illumination device is configured to provide the illumination light with a spatial intensity distribution which at least approximately compensates for an edge light drop. In particular, the edge light drop is a natural edge light drop, according to which a brightness in an image when a uniformly bright subject is imaged by a lens decreases by a factor of cos'M from that in the center of the image.

The natural Randlichtabfall, which by the so-called. cos'M (cosine high 4) law depends in a known manner on the focal length of the lens used. In the case of the described TOF sensor system, such an objective can be used to image the illumination light onto the scene and / or to image the scene onto a light receiver

Measuring device can be used. In the case of the use of lenses and preferably a common objective for both (emitted from a flat light source) illumination light and for (scattered by the area scene) measuring light without the described compensation of the natural marginal light waste would occur twice and the negative influence of cos 'M law would be correspondingly strong. Therefore, in the TOF sensor system in which both the illuminating light and the measuring light pass through an objective, the compensation of the natural marginal light drop described here contributes greatly to the improvement of the light intensity ratios. The compensation of the natural Randlichtabfalls by a suitable space angle-dependent distribution of the illumination intensity may be at least 30%, preferably 50%, more preferably 80% and even more preferably 90% or even 95%. These percentages refer (with a fixed focal length of the objective used) to the ratio between the intensities at the edge of the scene (for the illumination light) and at the edge of the image of the scene (for the measuring light) imaged on the measuring device, which (a ) with the described compensation and (b) occur without the described compensation of the natural edge drop.

Accordingly, 100% compensation would be complete

Mean elimination of natural edge light waste. In the case of a (fictitious) scene, which diffuses the illuminating light equally strongly in all subareas, the brightness in an image would be the same in all subregions, the image being the (complete) image of the scene on a light receiver of the measuring device.

According to a further embodiment of the invention, the

Sensor system further to a lighting device coupled to the illumination light controller, which is configured, the

Lighting device to control such that a characteristic of the illumination light, which describes the dependence of the illumination intensity of the illumination light of the solid angle, during a operation of the sensor system is dynamically changeable.

Through a dynamic variability of the characteristics of the

Lighting light can be one and the same scene at different

Illumination conditions (one after the other) are recorded several times. As a result, different data sets of one and the same scene are available to the data processing device, so that by means of a suitable method of image analysis (by the data processing device) that data record for determining the three-dimensional characteristic of the scene can be used, which reproduces the scene most accurately. If necessary, an "a priori knowledge" of the optical and / or

geometric properties of objects in the scene

be taken into account.

Furthermore, an optimal lighting characteristic can also be determined according to the "try-and-error" principle or by other statistical optimization procedures. This can be done dynamically during a real operation of the sensor system or as part of a calibration by means of a detection of suitable reference objects.

In some embodiments, those at different

Lighting characteristics recorded 3D images of the scene are processed together so that a comprehensive data set is available for a final determination of the 3D characteristic of the scene. In such a common processing, different partial areas of the scene can be characterized in that for a first partial area a first partial data record recorded in a first illumination characteristic and for a second partial area of the second partial data set recorded for a second illumination characteristic for the determination of the

Overall characteristic of the scene can be used. Of course, more than three can be used to capture the overall characteristics of the scene

Records are used, each of a different

Lighting light characteristic are assigned.

According to a further embodiment of the invention is the

Data processing device coupled to the illumination light controller and configured to evaluate the determined three-dimensional characteristic of the scene and based on a result of this evaluation to change the characteristic of the illumination light. Vividly, the way the scene depends on one

Scene detection is dependent on the angle of illumination illuminated by the illumination device, of measurement and evaluation results, which have been determined from a previous scene detection. The characteristic of the lighting becomes so dynamically on the basis of results of a

adapted to previous scene capture. This means that, correctly speaking, not only a control of the lighting device but rather a regulation thereof takes place. This advantageously allows a particularly accurate adaptation of the scene lighting with regard to an optimum

Scene analysis.

Appropriate control of the lighting device may depend on current environmental conditions resulting in the result of

Reflect scene evaluation. Such environmental conditions may be weather conditions such as the presence of rain, snow, hail, fog, smoke, suspended particles, etc. in the scene.

According to a further exemplary embodiment of the invention, the result of the evaluation depends on the optical scattering behavior of at least one object contained in the scene. This has the advantage that in addition to the distance-based

Compensation also an optionally existing different scattering behavior and / or reflection behavior of different objects in the scene is taken into account, so that the measuring light impinges with an at least approximately spatially uniform intensity distribution on a light receiver of the measuring device. A brightness which is as uniform as possible over the light-sensitive surface of the light receiver favors precise distance measurement by the described TOF sensor system.

It should be noted that in many objects, the litter or.

Reflection behavior of the wavelength or the frequency of Lighting light hangs. A consideration of such

Frequency dependence can be advantageous to another

Improvement of the scene lighting and the following

Contribute scene evaluation.

According to a further embodiment of the invention is the

Lighting device configured to control the characteristic of the illumination light in response to an external control signal.

The control signals can via a corresponding data input of the

Sensor system, in particular a data input of the illumination light control device, are received. To realize a suitable

Adjustment and / or regulation of the illumination characteristic, the control of the illumination device can then be carried out by the above-described illumination light control unit of the sensor system. A control or adaptation of the illumination characteristic can therefore not (only) depend on the information generated in the context of the TOF measurement or the results of the scene evaluation. According to the embodiment described here, a suitable adaptation of the

Lighting characteristics from external.

In principle, external control signals can be indicative of all features and / or states which have an influence on the backscattering behavior of the

Have illumination light. Such a feature is, for example, a (color) change of an object to be detected and / or an object newly entering or leaving the scene, which object

Backscattering at least partially influenced.

According to a further embodiment of the invention, in addition to the solid angle dependence, the characteristic of the illumination light is determined by at least one of the following features: (a) wavelength, (b) spectral intensity distribution, (c) polarization direction, and (d)

Intensity distribution for different polarization directions. By an application-specific use of one of these features or by a suitable combination of at least two of these features, the objects to be recognized can be illuminated particularly well and recognized as a result with particularly high accuracy and reliability.

The wavelength, frequency or color of the illumination light can by a suitable control of spectrally different light elements, in particular LEDs with different colors, varies or to the

expected characteristic of the scene to be adjusted. The polarization direction of the illumination light can in a known manner, for example by the

Use of polarizing filters can be set.

According to a further embodiment of the invention, the

Lighting device on (a) designed as a laser

Illumination light source for spatially scanning the scene with a

(b) an at least approximately punctiform illumination light source, (c) a plurality of individual ones

Illumination light sources, which are in particular individually controllable and in each case assigned to a specific solid angle region of the scene, and / or (d) a planar illumination light source, in particular with a luminous intensity which is not homogeneous over the surface.

A scanning the scene laser beam can be directed in a known manner via two rotatable mirrors with mutually non-parallel and preferably perpendicular to each other oriented axes of rotation to each illuminated point of the scene. For such a (dynamically adaptive) deflection can also non-mechanical optical elements such as diffractive

Optical elements (DOEs) are used. The deflection can in particular by the illumination light control device described above being controlled.

The at least approximately punctiform illumination light source may be a (sufficiently strong) semiconductor diode, for example a laser or light emitting diode. In order to illuminate the scene areally, suitable

Beam shaping systems, in particular lens systems are used. In order to realize the above-described spatially-dependent non-uniform illumination of the scene, suitable optical elements for beam deflection,

Beam splitting and / or beam merge can be used. Also DOEs can be used advantageously.

The plurality of illumination light sources, which are also in particular laser or light-emitting diodes, can be controlled (in particular individually) by the illumination light control device described above. This advantageously allows an adaptively controlled or even regulated adjustment of the characteristic of the illumination light.

A flat light source can also be the source for a spatially-dependent, non-homogeneous intensity distribution. If it is a spatially homogeneously illuminated surface, suitable optical elements for

Beam deflection, beam splitting, beam merging and / or beam shaping can be used to realize the described spatial angle-dependent uneven illumination of the scene.

According to a further embodiment of the invention, the

Lighting device at least one diffractive or refractive optical element which is configured, the space angle-dependent

To realize intensity distribution of the illumination light by means of spatial structuring of the illumination light.

The term diffraction (or diffraction) is used in this context generally designates the spatial deflection of an electromagnetic wave at structural obstacles. Such obstacles may be an edge, a hole or a one-dimensional, a two-dimensional or even a three-dimensional grid. The diffractive optical element can be, for example and preferably, a DOE, which advantageously has a dynamic adaptation or adaptation of the illumination characteristic during the

Operation of the sensor system allowed.

The term refraction (or refraction) refers to the change in the propagation direction of a wave due to a spatial change in its propagation velocity, which is specific to light waves through the

Refractive index n of a medium is described.

According to a further embodiment of the invention is the

Lighting device configured to provide the illumination light with a deviating beam cross section of a circular shape. This has the advantage that in scenes which are "not round", inadequate illumination of corner areas of the scene can be avoided. An inadequate

Although illumination of the corner areas could possibly be prevented by an overall increased intensity of the illumination light, in this case, the central areas of the scene would be overexposed, which would be very disadvantageous at least from an energetic point of view.

In many embodiments or applications of the sensor system, it is advantageous if the illumination light has a rectangular beam cross section. Preferably, the beam cross-section is adapted to achieve as homogeneous as possible illumination to the shape of the scene to be detected. A suitable shape of the beam cross section can be realized not only by a corresponding shaping of the luminous area of the illumination device, the beam cross section can also be adjusted by optical components such as mirrors and refractive optical elements (eg lens system) in a suitable manner become. Diffractive optical elements (DOEs) can also be used, which optionally even allow a dynamic and / or scene-dependent shaping of the beam cross-section. In addition, it is also possible to use micromirror arrays resulting from so-called digital light processing (DLP).

Projection technology are known. Even with so-called microelectromechanical systems (MEMS) devices, a large number of optical elements can be moved in such a way that a desired illumination angle dependent on the angle of illumination is obtained.

According to a further embodiment of the invention, the

Measuring device on a light receiver with a plurality of pixels for receiving the measuring light and coupled to the light receiver

A light receiver control device, wherein the light receiver control device and the light receiver are configured such that in a modified operation of the sensor system at least two pixels of the plurality of pixels are combined to form a higher-level pixel.

Typically, at least some of the plurality of pixels are grouped together so that a certain number of pixels are combined into a higher-level pixel. The certain number may be, for example, (preferably) two, three, (preferably) four, six, (preferably) eight, or (preferably) nine. Of course, an even stronger summary of pixels is possible.

Such aggregation of pixels, also referred to as "binning", has the effect of increasing the number of photons of the measurement light collected during a scene acquisition of one pixel, in proportion to the number of pixels, at the expense of spatial resolution pixels summed up to a parent pixel. As a result, the so-called statistical value is reduced, in particular in the case of weak measuring light

Photon noise, which improves the scene evaluation accuracy. A binning is therefore particularly advantageous in the case of a weak measuring light when high spatial resolution is not required.

It should be noted that binning can also be carried out locally in only at least a partial area of the active areas of the light receiver via the surface of the light receiver. Although this leads to an inhomogeneous spatial resolution, which is not necessarily desired. However, the disadvantage of such an inhomogeneous spatial resolution is overcompensated in many applications by the increased photon accumulation. A local "binning" can be done at least in some known light receivers without special electronic or apparatus elements simply by a corresponding control of the light receiver, which control determines the "binning" and thus the operating mode of the sensor system.

In preferred embodiments, a local "binning" is performed in such a way that, measured by the measuring device and / or learned by the data processing device, exactly those areas of the

Light receiver, which have received too little light energy in at least one previous scene detection, by a suitable control of the light receiver by the light receiver control device in subsequent scene captures in a suitable manner to higher-level pixels

be summarized. Such a dynamically controlled or regulated "binning" can during a normal operation of the sensor system (learned) and / or during the configuration of the sensor system, for example in the context of a (first) installation, a maintenance, a cyclic or

automatic re-configuration etc. are performed.

It is further noted that if the individual pixels are not square in number, the spatial resolution of the light receiver along different directions will be different if the individual pixels are square Have shape. This can be exploited in some cases in an advantageous manner. Such an application is present, for example, when a movement of an object of the scene along a previously known spatial direction is to be detected with high accuracy. In such a case, the number of pixels arranged along a line perpendicular to this known spatial direction (as depicted on the light receiver) may be larger than the number of pixels arranged along a line perpendicular thereto. Then the spatial resolution along the direction of motion is greater than the spatial resolution perpendicular to the

Direction of movement and the motion profile of such a linearly moving object can with a particularly high accuracy even at a

comparatively weak measuring light can be determined.

It should also be noted that the described binning is also adaptive in response to at least one previously acquired (and evaluated)

Scene characteristic (automatically) can be activated. This means that the "binning" is controlled not only controlled by the light receiver controller but depending on the results obtained by a scene evaluation. This will be a particularly reliable

Scene detection also allows for weak measuring light, so that the described sensor system with a correspondingly weak

Lighting light and thus can be operated in an energy efficient manner.

According to a further embodiment of the invention, the

A measuring device on a light receiver or the above-mentioned light receiver for receiving the measuring light and a light receiver downstream measuring unit which is configured to measure the light transit time based on (a) a measurement of the period between a transmission of a pulse of the illumination light and the reception of the pulse to the associated measurement light and / or (b) a measurement of a phase shift between a temporal modulation of the illumination light and an associated modulation of the received measuring light. This has the advantage that the described sensor system can be realized in a suitable manner, depending on the particular application, by utilizing a respectively suitable TOF measuring principle. In some embodiments, the sensor system is configured in such a way that it is possible to switch between the two different measurement principles "pulse mode" and "phase measurement" flexibly or, if necessary, between the two different measurement principles.

Regardless of the measuring principle used, the light receiver has a light-sensitive surface, which is subdivided into a multiplicity of pixels. With or on each pixel those photons of the measurement light are accumulated, which originate from a certain solid angle region or the associated subregion of the scene. The measuring unit is used to determine the runtime of the associated light beams of the illumination light and the measuring light for each pixel.

According to a further embodiment of the invention, the.

Sensor system further on a holder, which at least with the

The measuring device is mechanically coupled, wherein the holder is designed such that the sensor system can be attached to a stationary in relation to the scene to be detected holding structure.

In terms of clarity, the holder ensures that the described sensor system can be a stationary system which has a certain spatially fixed detection range and thus always monitors the same scene. By comparing different temporally spaced detections of the dependent of the orientation of the sensor system scene spatially stationary objects that are present in the scene can be detected in an image analysis and hidden in a further image analysis with respect to movement profiles. As a result, computing power can be saved and the energy efficiency of the described sensor system can be improved. The stationary support structure may be directly or indirectly mechanically coupled to a device for controlling a coverage characteristic of an opening to be passed through the object by at least one closure body.

Preferably, this device in addition to a suitable guide or

Storage of the closing body an actuator for moving the

Closing on, in particular for moving the closing body between a closed position and an open position (and vice versa).

In the field of building security, the opening may be an entrance, for example, for a person or a vehicle. The closing body may be a door, for example a front door or a garage door. The stationary support structure may be, for example, the stationary frame structure of an entrance, for example the frame of a door.

According to a further embodiment of the invention is the

Data processing device further configured such that a

Covering characteristic of an opening to be passed by an object by at least one closing body is controllable. As a result, the opening, which is, for example, an entrance (or an exit) of a building, can be automatically monitored in an energetically favorable manner, and by suitable actuation of an actuator, the closing body can be moved automatically between an open position and a closed position. For this purpose, the data processing device of the described

Sensor system coupled with the control of a known control system for a closure body.

In accordance with another aspect of the invention, a method of three-dimensionally capturing a scene is described. The described method comprises (a) illuminating the scene with illumination light by means of a Lighting device and by means of a measuring device (b) receiving measurement light which is at least partially backscattered by at least one object contained in the scene illumination light; and (c) measuring distances between the sensor system and the at least one object based on a light transit time of the illumination light and the measurement light. Furthermore, the described method comprises (d) determining the

Three-dimensional characteristic of the scene based on the measured distances downstream of one of the measuring device

Data processing device. In this embodiment, the

Lighting device configured such that an illumination intensity of the illumination light from the solid angle of the beam path of the

Lighting light depends, so that a distance-based loss of intensity of the illumination light and the measuring light is at least partially compensated.

The described method is also based on the knowledge that the intensity of the received measurement light, which is received by different and preferably all subregions of the scene, is at least approximately the same due to a suitable illumination angle dependent on the angle of the room. The spatial characteristic of the illumination light can be adjusted so that the intensity is always just as high as required for a reliable detection of the subarea of the scene assigned to the respective solid angle region. As a result, only as much energy as required is needed for the lighting and an energy-efficient three-dimensional one

Scene capture based on Time Of Flight (TOF) realized.

According to a method-related embodiment of the invention, the method further comprises (a) detecting an object in the scene;

(b) comparing the detected object with at least one in a

Database stored comparison object; and (c) if the object is within predetermined allowable deviations with a comparison object

matches, identifying the object as one for a particular action approved object.

The approved action may, for example, be an authorized passage through an opening in a building, which opening is closed by a closing body before being identified as an approved object and only after successful identification by a corresponding movement of the door

Closing body is opened. The objects to be identified may preferably be persons and / or vehicles. Successful identification may be to control or activate a closure mechanism for a closure body prior to opening a building.

According to a further aspect of the invention, a use of a sensor system described above for controlling a

Covering characteristic of an opening to be passed by an object by at least one closing body.

The described use is based on the finding that a detection and evaluation of an optical scene made in an energy-efficient manner can be used advantageously in passages which can be closed by a closing body. This is especially true for passages which a closure or a

Covering characteristic, which is controlled by the described sensor system or at least co-controlled. Because such sensor systems

Usually powered by the closure systems for the closure body, it is particularly important to operate with a comparatively small amount of energy and still to reliable TOF

Scene evaluations to come.

By the inventive use of the above-described

Sensor system can be monitored in an energetically efficient manner and larger distances, which naturally to an earlier detection of a Opening request of the closure body leads, which can be a great advantage especially for fast moving objects. Furthermore, the scene can be detected with a wider detection angle, which, for example, leads to an early detection of itself transversely to the opening

Cross-traffic and thus lead to a more reliable detection of objects in the security area of the closure system. This can be suppressed in cross traffic unnecessary opening request.

According to a further embodiment of the invention, the opening is an entrance or an exit, in particular an emergency exit in a building. By recognizing an existing, but possibly not moving object in a passage area can be an input or output

monitored, in particular a blocked emergency exit detected, and the

corresponding information to an affiliated system, for example to a monitoring system, transmitted.

According to a further embodiment of the invention, the object is a person or a vehicle. In this case, the building may in particular be a house or a garage.

According to another aspect of the invention, there is described a use of a sensor system described above for detecting and / or controlling traffic flows of objects moving through a scene of the sensor system, the scene being determined by a spatial detection range of the sensor system.

This described use is based on the finding that it is in a traffic detection and / or traffic flow control on a

Energy-efficient sensor technology arrives, since this sensor is typically constantly in operation and beyond, especially in larger traffic flows typically a very large number of such sensor systems are in use. The relevant for the traffic flow objects, for example, people, vehicles, products such. B. packages, suitcases, etc. be. Since a plurality or even a multiplicity of 3D sensors are usually used for such applications, energy savings have a particularly positive effect here.

It should be noted that embodiments of the invention have been described with reference to different subject matters. In particular, some embodiments of the invention are with apparatus claims and other embodiments of the invention with method claims or

Usage claims described. However, it will be readily apparent to those skilled in the art upon reading this application that, unless explicitly stated otherwise, in addition to a combination of features belonging to a type of subject matter, any combination of features that may result in different types of features is also possible

Subject matters belong.

Before describing exemplary embodiments of the invention with reference to the drawings, some technical considerations related to the invention will be described here.

In general, TOF-based sensor systems can be subdivided into two fundamentally different classes both with regard to the illumination light and with regard to the measurement light, which can be combined as desired.

Bl: The first alternative (Bl) for the lighting is characterized by the fact that the scene by means of a single illumination light beam high

Focusing and low divergence (ie high collimation) sequentially is scanned. For each position of the illumination light beam in the scene, a measurement of the duration of the illumination light and the measurement light

performed. The scanning can be realized using movable optical components, in particular mirrors. Alternatively or in

Combination can be used for sequential scanning of the scene with the

Illuminating light beam can be used a solid body, which manages without mechanically moving parts and has integrated photonic structures or circuits. With a suitable control of these structures, the illumination light beam is then directed to the desired location of the scene. Such a solid is known for example from US 2015/293224 Al.

B2: The second alternative (B2) for lighting is characterized by the fact that the entire scene is illuminated (all at once and flatly). If necessary, the intensity of the illumination light in selected subregions of the scene can be (selectively) increased in order to enable improved 3D object detection at these locations. Such spatially uneven distribution of the intensity of the illumination light can be done without moving optical

Components for example by means of a so-called. Diffractive optical element (DOE) take place.

Ml: A first alternative (Ml) for the measurement is based on pulsed

Illumination light beams. The "travel time" of a light pulse on the receiver side for each pixel within a time window is determined and derived from the distance.

M2: The second alternative (M2) for the measurement is based on a temporal, preferably sinusoidal, modulation of the illumination light with a

predetermined frequency, with appropriate values for this frequency depending on the expected transit time or the maximum detection distance. On the side of the light receiver, the phase difference is measured for each pixel and derived therefrom the distance information.

Both measuring principles M 1 and M 2 are based on an integration of the number of photons or the photoelectrons generated in the light receiver, which arrive on each pixel to be measured. In this context, it is obvious that an ever-present light or photon noise depends on the number of photons accumulated in a pixel. Therefore, the higher the number of accumulated photons, the more accurate the distance information obtained from the TOF measurement becomes.

Further advantages and features of the present invention will become apparent from the following exemplary description of presently preferred embodiments.

Short description of the drawing

Figure 1 shows the use of a sensor system for controlling a

Covering characteristic of an opening by means of closing bodies designed as sliding doors.

Figure 2 shows the use of a sensor system for detecting a

Traffic flow of transported on a conveyor belt objects.

Figures 3a and 3b illustrate a collection of single pixels of a light receiver.

Figures 4a to 4c show different beam cross sections of a

Lighting light to adjust the lighting to the shape of the

capturing scene. Detailed description

It should be noted that the following

Embodiments only a limited selection of possible

Represent variants of the invention. In particular, it is possible to suitably combine the features of individual embodiments with one another, so that a multiplicity of different embodiments are to be regarded as obviously disclosed to the person skilled in the art with the embodiment variants explicitly illustrated here.

Before the figures are described in detail in this section, some aspects of a number of embodiments are explained below.

Given the importance of energy - efficient operation in many applications of 3D sensor systems, it can be applied to the

Light receiver to optimize the incident optical energy of the measuring light by illuminating the scene differently (intensively) depending on the characteristics of the scene.

However, for most applications of TOF sensor systems, the scene to be captured is cuboidal or cubic in nature. However, known TOF sensors typically have a detection range that has at least approximately the same range for all detected solid angles. The

(Outside) boundary of the detection area is therefore part of a spherical shell (where all points have the same distance to the TOF sensor system).

The TOF sensor system described in this document is now able to at least partially compensate for this "spherical shell boundary" by selectively increasing or reducing the illumination intensity in selected subregions of the scene. By reducing the illumination intensity in the center of the scene and increasing the illumination intensity against the scene Edge of the scene and in particular to the corners, this can be described with the above-described cos' law described adverse effect and optimally utilized the energy used for lighting.

Furthermore, certain subregions of the scene which are dependent on the spatially geometrical arrangement of the sensor system and the scene to be detected can be "exposed" in a generalized manner with an optimum illumination intensity. For example, a TOF sensor system is typically mounted above the average height of the objects to be observed (people, products, vehicles, etc.) so that unwanted object shadowing is less problematic in a variety of objects. However, this means that in most cases the upper part of the scene contains larger measurement distances than the lower part.

This knowledge about the mounting location of the sensor system in relation to the

Capturing scene can be used to further optimize the operation of the

be taken into account in particular with regard to the energy efficiency by the upper area of the scene accordingly less heavily lit or "exposed".

Apparently, lighting dependent on the geometry of the scene can be realized by controlling the illumination angle-dependent illumination intensity. Depending on the light source, a different strategy can be used.

(1) In a light source consisting of a plurality of individual illuminance-providing elements which constitute the entire illumination device (e.g., an array of laser or light-emitting diodes), the

Brightness of a single element varies with respect to the other elements. This variation can be both constructive in design (e.g., laser or

LEDs with different intensity) as well as by the type of

Control (via variable current per laser or light emitting diode by means of suitable electronics, for example by measuring in the (initial) installation set). Furthermore, a dynamic adjustment of the individual laser or LEDs during operation is possible. In this case, simply those laser or light emitting diodes, which are assigned to areas of the scene that provide little measuring light, are correspondingly more energized. This is particularly well suited for the above lighting principle B2 in combination with the aforementioned measuring principle Ml or M2.

(2) In lighting devices which sequentially scan (scan) the entire scene with an illuminating light beam, the respective instantaneous solid angle of the illuminating light beam is known at all times. By varying the intensity of this illumination light beam as a function of the respective solid angle, the illumination intensity can thus be dependent on the

Scene geometry (and with optional dynamic "result control" also depending on the amount of reflection or scattered light) for each solid angle, the illumination intensity can be specifically controlled. Thus, a static scene can be measured, with the appropriate intensity for each solid angle is taught to illuminating light.

The above-explained and optional dynamic adjustment of the intensity of illumination light can be done adaptively both in real time and from "frame to frame". This is for the parts of the scene, of which too little

Measuring light is received, immediately the intensity of the corresponding

Part (lighting) increased. This means that depending on the

Result values of a final scene capture for the next scene capture those areas with "overexposure" attenuated and illuminated

lighten those with "underexposure". This approach is particularly well suited for the lighting principle Bl in combination with the

Measuring principle Ml or M2.

An embodiment of the invention achieves energy savings by means of dynamic lighting energy optimization, wherein Illumination energies of different wavelengths or frequencies are used. Depending on the color of the object, for example, the wavelengths that contribute to the most intense reflections or

Light scattering lead to be emitted with a lower intensity. In contrast, other wavelengths or other wavelength regions with less reflection or scattering may be present in the wavelength spectrum with a higher intensity. Thus, for example, a red object can be illuminated primarily with a red light component and the green and blue light components are reduced (for the relevant solid angle), preferably to at least approximately zero intensity. The same principle can also be applied in the relationship between visible light and infrared (IR) light.

The information obtained in the context of a variable frequency or wavelength variable illumination with respect to reflection and scattering properties with associated distance and solid angle can be used in a subsequent

Scene analysis of moving objects can be of great advantage, because it allows easier objects to be detected and tracked, since the

Functional cohesion of spatial points on the reflection or scattering properties can be interpreted in addition grouping.

The sensor system described in this document may be used, for example, in passageways, especially in passageways having a shutter characteristic that is automatically controlled (e.g., by means of doors, gates, barriers, traffic lights, etc.). Since the sensors for a

Passage control is usually powered by the existing closure systems with energy, it is with a given amount of energy as much sensory effect to achieve. The sensor system described in this document allows, compared to known sensor systems (i), data acquisition for longer distances (earlier detection of a

Opening request, especially for faster moving objects), (ii) wider coverage angle (eg early detection and tracking of

Cross-traffic) and / or (iii) a more reliable detection of objects in a security area of the closure system.

In some embodiments, a receiving chip whose pixels have different sensitivities is used for the light receiver. This can e.g. by reducing the noise of individual pixels or zones of pixels. Since the noise is often correlated with the heat of the sensor, e.g. by means of a heat pump (for example a Peltier element) a higher sensitivity can be achieved for a part of the receiving chip. The more punctual this

Temperature change can be generated on the receiving chip, the higher the energy efficiency of the sensor system can be. Thus, for example, in a particular embodiment, a temperature gradient over the

Imprint a receiving chip so that the measuring light coming from a more distant zone of the scene reaches a cooler zone of the receiving chip.

In a further embodiment, which is especially for the

Lighting principle B2 is suitable, an (additional) spatial variation of the illumination light is achieved by DOE's. With DOEs in the context of laser systems, the maximum illumination energy can thus be utilized, because those portions of the illumination light beams, which should strike the scene at a lower intensity, are not simply passed through a mask

but their intensity is redistributed by the DOE to other areas of the scene. Thus, the energy of the illumination light can be almost completely utilized. The same effect of the concentration of illumination light in a portion of the scene (albeit at a lower efficiency) can also be achieved by mechanisms such as those for

Pattern projections are required, which are required for 3D sensors, which are based on the known principle of structured illumination or the so-called. Strip projection. The spatial variation of the illumination light described here can also be used with additional lens systems, in particular Freeform lenses are additionally optimized. Illustratively, the room-angle-dependent illumination intensity described in this document provides for scene-dependent illumination, which results in a more uniform distribution of the intensity of the light received from the different parts of the scene

Measuring light leads.

In a further embodiment, the scene to be detected is first illuminated conventionally, in particular according to the illumination principle B2.

After determining the distance information of the whole scene in the following scene captures the "overexposed regions" with a

illuminated lower illumination intensity. Particularly in sensor systems which are intended to detect temporal changes of objects in the scene, the sensor system can be operated at the lower limit of the measurability as long as the scene is (still) static. However, if a change in the scene is (grossly) detected or at least suspected, then an increase in the illumination intensity can be reacted immediately, so that the scene or the scene changes can then be detected and evaluated with high accuracy. This mechanism can be used both for IR sensor systems and for sensor systems with

work visible light.

In the following detailed description referring to the figures, features of different embodiments, which are the same or at least functionally identical to the corresponding features or components of another embodiment, are provided with the same reference numerals or with reference numerals, which in the last two digits are identical. In order to avoid unnecessary repetitions, features or components already explained on the basis of a previously described embodiment will not be explained in detail later. 1 shows the use of a sensor system 100 to control a coverage characteristic of an opening 184 depending on the characteristics of a scene 190 monitored by the sensor system 100. According to the embodiment shown here, the opening 184 is an entrance for persons into a building or garage entrance for motor vehicles. The corresponding input structure is provided with the reference numeral 180. An object 195 in the scene is intended to symbolize such a person or a motor vehicle.

The input structure 180 comprises a stationary support structure 182, which constitutes a frame and a guide for two closing bodies 186 designed as sliding doors. The sliding doors 186 can each be represented by means of a motor 187 along the two thick double arrows

Move instructions are moved. The actuation of the motors 187 takes place, as explained below, by means of the sensor system 100 described in this document.

The sensor system 100 has a TOF measuring device 110, a

Data processing device 150 and a database 160. The TOF measuring device 110 in turn has a lighting device 130 and a light receiver 120. As shown here

Exemplary embodiment comprises the TOF measuring device 110 or are associated with the TOF measuring device 110 (i) an illumination light control device 135 for controlling the operation of the illumination device 130, (ii) a measuring unit 125 connected downstream of the light receiver 120 for measuring a

Light propagation time between illumination light 131 emitted from the illumination device 130 and measurement light 196 received by the light receiver 120, and (iii) a light receiver control device 140 for controlling the operation of the light receiver 120. In particular, all optical components of the sensor system 100 are accommodated in the TOF measuring device 110. On a housing of the TOF measuring device 110, a holder 111 is provided. By means of this holder 111, at least the TOF measuring device 110 is attached to the stationary holding structure 182 in a mechanically stable and spatially fixed manner. Preferably, the whole sensor system 100 (in contrast to the representation of FIG. 1) is constructed as a module which, in addition to the TOF measuring device 110, also has the data processing device 150 and the database 160 within a compact design.

According to the embodiment shown here, the light receiver control device 140 has an interface 142, via which an external control signal 142a can be received. The external control signal may be from an attached system (not shown), such as a

Monitoring system, which controls the operation of the sensor device 100 depending on external parameters. Such an external parameter may be, for example, a previously known optical property of the object 195. Also a below with reference to the figures 3a and 3b described

Scene-dependent grouping of pixels of the light receiver 120 may be initiated by the control signal 142a.

Signaling data transmitted via the interface 142 may also include information about the detected and evaluated scene 190. Such information may be, for example, the information that an escape route is blocked, that a license plate written out for search has been recognized, a parking lot has been illegally occupied, a suspicious object is in the monitored scene 190, etc. In this case, a corresponding information flow from the sensor system 100 or more precisely from the light receiver control device 140 to the affiliated system. Alternatively or in combination, such signaling data 152a may also be be output from the data processing device 150 via an interface 152.

An external control signal 152a transferred to the data processing device 150 via the interface 152 can also be used to make the operation of the data processing device 150 at least partially dependent on external information. In particular, via the control signal 152a an "a priori knowledge" can be transmitted via an object 195 for an improved evaluation of the detected scene 190 and in particular for an improved object recognition.

According to the embodiment shown here, the illuminated

Lighting device 130, which may be, for example, an array of individually controllable laser or light-emitting diodes, the scene 190 and thus also located in the scene 190 object 195 with a pulsed and thus temporally modulated illumination light 131. The illumination light control device 135 is configured, the Lighting device 130 to control such that a characteristic of the illumination light 131, which describes the dependence of the illumination intensity of the illumination light 131 of the solid angle (in which the illumination light 131 strikes the scene 190), during a operation of the sensor system 100 is dynamically changeable. Alternatively, or in combination, the illumination light controller 135 may also cause the characteristic of the illumination light 131 to at least approximately compensate for natural edge light falloff, according to which brightness in an image when imaging a uniformly bright subject through an objective not shown for clarity decreases the factor cos' with respect to the brightness in the center of the image picked up by the light receiver.

The space angle-dependent intensity distribution of the illumination light 131 is illustrated in FIG. 1 by arrows of different widths and dashed lines. In this case, a broad arrows for a high illumination intensity in the respective solid angle range (in) and a narrow arrow to illustrate a comparatively low intensity of the corresponding illumination light beams. In order to achieve the most uniform possible distribution of the intensity of the backscattered measuring light 196 (only two measuring light beams are shown in FIG. 1 for reasons of clarity), solid angles of the scene 190, which are associated with a larger measuring distance, are illuminated more strongly than solid angles, which have a smaller measuring distance assigned.

The illumination light controller 135 may be the characteristic of the

Illumination light 131 depending on an external control signal 137

determine which is transferred via an interface 137. The

Control signal 137a may be indicative of the space angle dependent

Illumination intensity and / or for further properties of the

Illumination light 131, for example its (a) wavelength, (b) spectral intensity distribution, (c) polarization direction, and (d) intensity distribution for different polarization directions. These further properties can be selected such that they contribute to the most reliable and accurate object recognition possible. Again, a "a priori knowledge" about optical properties of the object 195 can be considered.

The light receiver 120 of the TOF measuring device 110 receives illuminating light 131 backscattered from the object 195. This backscattered light is referred to as measuring light 196 in this document. The spatial detection of the scene 195 takes place on the basis of the principles explained in detail above of a transit time measurement, which is also referred to as Time Of Flight (TOF) measurement. The corresponding TOF data is transferred to the data processing device 150. This can be done directly or indirectly via the

Light receiver controller 140 done. It should be noted that the illumination device 130 in addition to the illumination units shown in Figure 1 can also have other lighting units that illuminate the scene 190 from a different angle. Likewise, the two lighting units can also be arranged outside the housing of the TOF measuring device 110 and thus be further spaced from the light receiver 120. On the principles of

performed TOF measurement does not change anything.

According to the exemplary embodiment illustrated here, based on this 3D data, the detected optical scene 190 is identified by means of suitable methods

Image evaluation evaluated. For this purpose, a plurality of images taken by the scene 190 under different illumination conditions or different illumination characteristics may be shared.

To capture a motion profile of the object 195, 3D images of the scene 190 can be recorded within certain time intervals. Thus, the data processing device 150 is able, based on corresponding position shifts of the object 195 not only its speed as an absolute value but as a motion vector (with a

Direction information). Knowledge of the exact position and / or motion profile of the object 195 may then be advantageously used to appropriately drive the two motors 187 from the data processing device 150. According to the embodiment shown here are at a closed opening 184 the

Sliding doors 186 open only when the object 195 actually moves in the direction of the opening 184. If the object 195 is a vehicle of so-called cross traffic, which is located in the

Moving substantially past the opening 184, then the corresponding motion vector is detected by the data processing device 150 and there is no opening of the sliding doors 186. After passing the object 195 through the opening 184, it can be quickly closed again, for example, to pass further

Prevent objects. In this connection, it is obvious that not only the time at which the opening must be released, but also the period of time for which the opening 184 must be kept open depends on the speed of the object 195 with which it is moving in the direction of the opening 184 and through the opening 184 therethrough.

According to the embodiment illustrated here, the sensor system 100 is also capable of performing object recognition. This is what the

Data processing device 150 to a stored in the database 160 record of reference objects corresponding to selected objects that are authorized to pass through the opening 184. This means that with a suitable approach of the object 195 to the input 184, the sliding doors 186 are opened only when the detected object 195 at least approximately coincides with one of the stored reference objects. This clearly indicates that in the use described here of the

Sensor system 100, the coverage characteristic of the opening 184 depends not only on the motion profile of the object 195, but also that an object-based access control takes place.

FIG. 2 shows a further use or a further use of the invention

Sensor system 100. For reasons of clarity, only the TOF measuring device 110 of the sensor system 100 is shown in FIG.

According to the embodiment illustrated here, the TOF measuring device 110 detects a traffic flow of (various) objects 295a, 295b, 295c, 295d and 295e, which are on a conveyor belt 298 and along the direction of movement represented by an arrow through a scene 290 move through. A reliable knowledge of the number and / or the type of objects 295a to 295e can be used in the field of logistics for traffic flow control. Only an example of such

Controlling a traffic flow is the control of luggage transport in an airport. In this case, labels on the relevant objects 295a - 295e can also determine the type of the respective object. It should be noted, however, that use in an airport is merely one example of a variety of other uses in the field

Traffic control is.

FIGS. 3a and 3b illustrate a combination of individual pixels of a light receiver 320a designed as a semiconductor or CCD chip;

320b. The light receiver 320a has a plurality of light-sensitive or

Photon collecting pixels 322a. As shown here

Embodiment, the pixels 322a are associated with the full spatial resolution of the light receiver 320a, which resolution is predetermined by the semiconductor architecture of the chip 320a.

In the light receiver 320b, four of the light-sensitive pixels (for a full resolution) are respectively added to a higher-level pixel 322b (for an increased resolution)

Photon accumulation per pixel at the expense of a reduced spatial

Resolution). Illustratively, a pixel 322b collects a four-fold amount of light compared to a single pixel 322a. Such a "binning" reduces the required

(Minimum) intensity of the detected measurement light, which is needed to evaluate the corresponding image area of the scene. Since the intensity of the measurement light depends directly on the intensity of the illumination light, binning reduces the intensity of the illumination light and thus reduces the energy consumption of the sensor system. The described "binning" can also be realized dynamically by a corresponding control of one and the same light receiver 320a or 320b. The light receiver is either in a first operating mode (with full resolution) or in a second operating mode (with

operated photon-collecting pixels) operated. Switching between different modes of operation may be controlled by external control signals (see reference numeral 142a in Figure 1). Alternatively or in combination, such switching may also depend on the result of a scene evaluation, such that the "binning" mode of operation for a next

Scene capture is regulated.

It should be noted that more than two different

Operating modes, each with a different strong summary of pixels can be used. Furthermore, it is possible to combine a different number of individual pixels into a higher-order pixel in different partial areas of the light receiver. Then, individual portions of the scene with a higher spatial resolution (and less photon accumulation) and other portions of the scene with a lower spatial resolution (and higher

Photon accumulation). The described local and

Different levels of pixel aggregation can be carried out dynamically or adaptively in exactly those subregions in which a particular object is currently located.

Figures 4a to 4c show different beam cross sections of a

Lighting light to adjust the lighting to the shape of the

capturing scene. A first illumination light 431a illustrated in FIG. 4a has a substantially circular beam cross section and is preferably suitable for "round scenes". However, for most applications that do not capture (and evaluate) a "round scene," one of a circular shape is appropriate deviating beam cross section. FIG. 4b shows an illumination light 431b with an elliptical beam cross section. FIG. 4c shows

Illumination light 431c with a rectangular beam cross section. As

already mentioned above, the beam cross section through a

corresponding shaping of the illumination device and / or by optical components such as mirrors and refractive optical elements (e.g.

Lens system) are suitably adapted to the scene to be detected. Diffractive optical elements (DOEs) can also be used, which optionally even allow a dynamic and / or scene-dependent shaping of the beam cross-section.

It is noted that the term "comprise" does not include other elements

excludes and that the "one" does not exclude a plurality. Also, elements described in connection with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Reference sign:

100 sensor system

110 TOF measuring device

111 bracket

120 light receiver

125 measuring unit

130 lighting device

131 illumination light

135 illumination light controller

137 interface

137a external control signal

140 light receiver control device

142 interface

142a external control signal

150 data processing device 152 interface

152a external control signal

160 database

180 entrance structure

182 stationary holding structure

184 opening / entrance

186 Closing body / sliding door 187 Engine

190 scene

195 object

196 measuring light 290 scene

295a-e objects

298 conveyor 320a / b light receiver / sensor chip

322a pixels

322b parent pixel / pooled pixel

431a Illumination light with round cross-section

431b Illuminating light with elliptical cross section

431c Illuminating light with rectangular cross section

Claims

P a n t a n s p r e c h e

A sensor system (100) for three-dimensionally capturing a scene (190) comprising the sensor system (100)

an illumination device (130) for illuminating the scene (190) with illumination light (131);

a measuring device (110)

for receiving measurement light (196) which is at least partially backscattered by at least one object (195) contained in the scene illumination light (131), and

for measuring distances between the sensor system (100) and the at least one object (195) based on a light transit time of the

Illumination light (131) and the measurement light (196); and

a data processing device (150) connected downstream of the measuring device (110) for determining the three-dimensional characteristic of the scene (190) based on the measured distances;

wherein the illumination device (130) is configured such that a

Illumination intensity of the illumination light (131) on the solid angle of the beam path of the illumination light (131) depends, so that a

Distance-based intensity loss of the illumination light (131) and the

Measuring light (196) is at least partially compensated.

2. Sensor system (100) according to the preceding claim, wherein

the illumination device (130) is configured to provide the illumination light (131) with a spatial intensity distribution that includes a

Randlichtabfall at least approximately compensated, in particular a

natural edge light fall according to the one brightness in an image

Imaging an evenly bright subject through a lens by a factor of cos' relative to the brightness in the center of the image decreases.

3. A sensor system (100) according to one of the preceding claims, further comprising

an illumination light controller (135) coupled to the illumination device (130) and configured to illuminate the illumination device

(130) in such a way that a characteristic of the illumination light (131) which describes the dependence of the illumination intensity of the illumination light (131) on the solid angle is dynamically changeable during operation of the sensor system (100).

4. Sensor system (100) according to the preceding claim, wherein

the data processing device (150) is coupled to the illumination light control device (135) and is configured to evaluate the determined three-dimensional characteristic of the scene (190) and, based on a result of this evaluation, the characteristic of the illumination light

(131) change.

5. Sensor system (100) according to the preceding claim, wherein

the result of the evaluation depends on the optical scattering behavior of at least one object (195) contained in the scene (190).

6. Sensor system (100) according to one of the three preceding claims, wherein the illumination device (130) is configured to change the characteristics of

Lighting light in response to an external control signal (142 a) to control.

The sensor system (100) according to one of the four preceding claims, wherein the characteristic of the illumination light (131) in addition to the

Solid angle dependence is determined by at least one of the following features:

(a) wavelength, (b) spectral intensity distribution, (c) polarization direction, and (d) intensity distribution for different polarization directions.

8. Sensor system (100) according to one of the preceding claims, wherein the illumination device (130)

(a) an illumination light source formed as a laser for spatially scanning the scene with a transmitted laser beam illumination light,

(b) an at least approximately punctiform illumination light source,

(C) a plurality of individual illumination light sources, which are in particular individually controllable and each associated with a certain solid angle range of the scene, and / or

(D) a flat illumination light source, in particular with a light intensity not homogeneous over the surface.

9. sensor system (100) according to the preceding claim, wherein the

Lighting device (130)

at least one diffractive or refractive optical element which

is configured, the space angle-dependent intensity distribution of the

To realize illumination light by means of spatial structuring of the illumination light.

10. Sensor system (100) according to one of the preceding claims, wherein the illumination device (130) is configured,

to provide the illumination light (131) with a beam cross-section (431b, 431c) deviating from a circular shape.

11. Sensor system (100) according to one of the preceding claims, wherein the measuring device (110)

a light receiver (120) having a plurality of pixels (322a) for receiving the measurement light (196) and

a light receiver controller (140) coupled to the light receiver (120), wherein the light receiver controller (140) and the light receiver (120) are configured to operate in a modified manner Operation of the sensor system (100) at least two pixels (322 a) of the plurality of pixels (322 a) to a higher-level pixel (322 b) are combined.

12. Sensor system (100) according to one of the preceding claims, wherein the measuring device (110)

or, if referred to the preceding claim, the light receiver (120) for receiving the measuring light (196) and

a measurement unit (125) connected downstream of the light receiver (120) and configured to measure the light propagation time based on

(a) a measurement of the time span between a transmission of a pulse of the

Illumination light (131) and the reception of the pulse associated with

Measuring light (196) and / or

(b) a measurement of a phase shift between a temporal

Modulation of the illumination light (131) and an associated temporal

Modulation of the received measuring light (196).

13. The sensor system (100) according to one of the preceding claims, further comprising

a holder (111) which is mechanically coupled at least to the measuring device (110), wherein the holder (111) is designed such that the sensor system (100) is fixed to a holding structure (182) stationary relative to the scene (190) to be detected ) is attachable.

14. The sensor system according to claim 1, wherein the data processing device is further configured such that a coverage characteristic of an opening to be passed from an object can be controlled by at least one closure body.

15. A method of three-dimensionally capturing a scene (190) comprising the method

Illuminating the scene (190) with illumination light (131) by means of a lighting device (130);

by means of a measuring device (110),

Receiving measurement light (196) which is at least partially backscattered by at least one object (195) contained in the scene (190); and

Measuring distances between the sensor system (100) and the at least one object (195) based on a light transit time of the

Illumination light (131) and the measurement light (196); and

Determining the three-dimensional characteristic of the scene (190) based on the measured distances by means of a data processing device (150) connected downstream of the measuring device (110);

wherein the illumination device (130) is configured such that an illumination intensity of the illumination light (131) depends on the solid angle of the beam path of the illumination light (131), so that a

Distance-based intensity loss of the illumination light (131) and the

Measuring light (196) is at least partially compensated.

16. The method according to the preceding claim, further comprising

Detecting an object (195) in the scene (190);

Comparing the detected object (195) with at least one comparison object stored in a database (160); and,

if the object (195) agrees with a comparison object within predetermined permissible deviations, identifying the object (195) as an object (195) permitted for a particular action.

17. Use of a sensor system (100) according to one of the preceding claims 1 to 14 for controlling a coverage characteristic of one of an opening (184) to be passed through an object (195) by at least one closing body (186).

Use according to the preceding claim, wherein

the opening (184) is an input or an output, in particular a

Emergency exit in a building.

19. Use according to one of the two preceding claims, wherein the object (195) is a person or a vehicle.

20. Use of a sensor system (100) according to one of the preceding claims 1 to 14 for detecting and / or controlling traffic flows of objects (295a-295e) which move through a scene (290) of the sensor system (100), wherein the Scene (190) by a spatial

Detection range of the sensor system (100) is determined.