WO2020229186A1

WO2020229186A1 - 3d sensor system which can be operated in different operating modes on the basis of the operating state of a closing body

Info

Publication number: WO2020229186A1
Application number: PCT/EP2020/061901
Authority: WO
Inventors: Heinz Macher; Urs Hunziker
Original assignee: Bircher Reglomat Ag
Priority date: 2019-05-10
Filing date: 2020-04-29
Publication date: 2020-11-19
Also published as: DE102019112338A1

Abstract

The invention relates to a sensor system (100) and to a method for three-dimensionally capturing a scene (190) in a specified spatial region which is assigned a closing body (186) for a passage (184). The sensor system (100) has: (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 (196) at least partially backscattered by at least one object (195) contained in the scene (190), 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 (195); (c) a data-processing and control device (150) connected downstream of the measuring device (110) for ascertaining a three-dimensional characteristic of the scene (190) on the basis of the measured distances; and (d) a data input (151) for receiving an input signal (151a) which indicates the current operating state of the closing body (186). The lighting device (130) and/or the measuring device (110) can be operated in a first operating mode with a first energy consumption and in a second operating mode with a second energy consumption which is lower than the first energy consumption. The invention additionally relates to the use of such a sensor system (100).

Description

3D sensor system, can be operated in different operating modes depending on the operating state of a closure body

Technical area

The present invention relates to a sensor system and a method for three-dimensional detection of a scene based on time of flight measurements. The present invention also relates to a use of such a sensor system.

Background of the invention

For opening and / or closing openings or passages, closing bodies operated by means of actuators are often used, which for

Operators facilitate the handling of the relevant closure body or are operated automatically without any operator action, for example when an object to be passed through the opening comes into the area of the opening. Such an opening can be a passage in a building, for example. A closing body can be a door, for example.

In order to ensure a high level of operational safety from automatically opening and closing

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

In addition, in some applications such a sensor system can automatically open and / or close the closure body or the

Initiate opening. From EP 2 453 252 B1 a 3D sensor system is known for the application area of monitoring automatically opening doors, which is based on the principle of measuring the transit time of light beams,

Illumination sources are emitted and detected by a light receiver after an at least partial reflection or 180 ° backscatter. Such sensor systems are generally referred to as "time-of-flight" (TOF) sensor systems. However, TOF sensor systems have the disadvantage that with

As the distance d of the object to be detected increases, the intensity of the measurement light to be detected (backscattered) by a light receiver of the TOF sensor is weakened in two ways. In the case of a point illumination light source without special focusing, this is scaled

Attenuation of the illuminating light emitted by the illuminating sources with l / d ^ 2, where d is the distance to the illuminating light source. The same applies to the measuring light if you have a point on the object where the

Illuminating 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 measurement light. In the case of beam shaping implemented in any way, for example focusing the illuminating light and / or the measuring light in the direction of the light receiver, the

The intensity attenuation is correspondingly lower, but nevertheless contributes to a significant loss of light output. This in turn leads to a

correspondingly poor energy efficiency of a TOF sensor system.

A system for automatically monitoring an opening or passage which can be closed by two sliding doors is known from WO 2018/064745 A1. Here too, 3D cameras are used, which are based on the TOF principle. A spatial area to be captured around a

The movement area around the sliding doors is divided into two sub-areas that are evaluated separately from each other. In a first sub-area, attention is paid to security in order to prevent an object from being trapped by the sliding doors. In the second sub-area, an image evaluation takes place in With regard to another purpose, for example for activating the sliding doors or for counting objects, which this second

Pass sub-area.

The present invention is based on the object in the field of automatic monitoring of openings, which by means of at least one

Closing body can be closed to enable an efficient and nevertheless reliable three-dimensional detection of a scene from an energetic point of view.

Summary of the invention

This task is solved by the subjects of the independent

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

According to a first aspect of the invention, a sensor system is described for three-dimensional detection of a scene in a predetermined spatial area, which is assigned to a closure body for a passage. The sensor system described has (a) an illumination device for illuminating the scene with illuminating light; (b) a measuring device (bl) for receiving measuring light, which is at least partially back-scattered illumination light from at least one object contained in the scene, 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 measuring light; (c) a data processing and control device connected downstream of the measuring device for determining a three-dimensional characteristic of the scene based on the measured distances; and (d) a

Data input for receiving an input signal which is indicative of a current operating state of the closure body. The

The lighting device and / or the measuring device are in a first Operating mode with a first energy consumption and in a second

Operating mode can be operated with a second energy consumption which is smaller than the first energy consumption.

The described sensor system, which is a so-called. Time Of Flight (TOF)

Sensor system is based on the knowledge that the energy consumption of a 3D sensor (system), which energy consumption is typically significantly greater than that of a 2D sensor, can be easily reduced if it is always operated in an "energy-saving mode" when the requirements for scene monitoring are not so great. This is the case with a 3D sensor that is used to monitor a passage that can be closed by a closure body, for example when the closure body is at rest or when it is moved in the direction of an opening position. Then there is namely the danger that an object, in particular a person, which (s) is in a range of motion of the

Closing body is located, is clamped by the closing body, does not exist or at least significantly reduced.

The operating state of the closing body can be a state of movement of the closing body and can in particular be determined by whether the closing body is in the direction of its opening position or its

Closing position moved. The speed at which the closure body moves can also characterize the state of movement. Furthermore, the operating state can also depend on the current position of the closure body, this position being a rest position or a current position over which the closure body is currently moving.

The operating mode of the lighting device and / or the measuring device can be any type of operating mode that (also) determines the energy consumption of the entire sensor system. The energy consumption can relate to the lighting device and / or the measuring device. The term “scene” can in particular be understood to mean that spatial area which is evaluated by the sensor system using image processing methods, the scene being recorded in a certain spatial area. Objects in the scene are recognized by suitable image evaluation. The

Data processing and control device based on known methods

Image evaluation and / or image analysis can be used. The

The data processing and control device can accordingly be a special image processing processor and can have one that is configured to use known methods for image evaluation and / or image processing

apply or carry out.

In this document, the term “illuminating light” is to be understood as meaning those electromagnetic waves which are emitted by a light source of the illuminating device and strike the relevant object in the scene. The "measuring light" are the electromagnetic waves scattered back from or on the object, which are emitted by the measuring device or a

Received light receiver of the measuring device and used for the three-dimensional evaluation of the scene.

The terms “optical” and / or “light” can refer to electromagnetic waves that have a specific wavelength or frequency or a specific spectrum of wavelengths or frequencies. In particular, the electromagnetic waves used can be assigned to the spectral range that is visible to the human eye. Alternatively or in combination, electromagnetic waves assigned to the ultraviolet (UV) or the infrared (IR) spectral range can 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 by means of the

Light receiver of the sensor can be detected. The term “object” can be understood to mean any three-dimensional physical structure which has a surface quality that leads to at least partial reflection or scattering of illuminating light and is thus visible to the measuring device through the resulting measuring light. The object can be an object such as a motor vehicle or a living being such as a person. The object can be a related to the

Be a static or stationary object. Furthermore, the object can also move within the scene, leave it or enter it.

The movement of the object (according to the law of speed = path / time) can then be determined by repeated scene detection (by comparing the different spatial positions determined with different scene detections). Depending on the application, the

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

The size and / or shape of the spatial area that the

Closing body is assigned, can depend on the type of

Closing body and its movement behavior. It can also depend on the expected speed at which objects approach the passage and possibly want to pass it. Also from one to be expected

Attention of the objects, especially of people possibly in one

Vehicle, the size and / or shape of the spatial area may depend.

The wear body can be any desired barrier element by means of which an opening can be temporarily at least partially closed. The closing body can be, for example, (i) a sliding door, (ii) a revolving door, (iii) a turnstile, (iv) a gate, in particular a garage door, (v) a barrier, in particular at a level crossing or a vehicle entrance or

Vehicle exit. The type of closure body can in particular depend on the type of passage and / or on the type of objects for which the passage is to be opened or closed. The danger posed by a closure body can in particular be determined by its closing edges when the closure body moves, in particular opens. Closing edges can be in

Main closing edges, secondary closing edges and counter closing edges are divided. A primary edge of the closing body is referred to as the main closing edge. This is usually that closing edge which, when the closing body moves, covers the greatest distance and thus (with the greatest speed) sweeps over the largest area. The

Main closing edge determines the main hazard zone of the closing body. Secondary edge (s) of a closure body are referred to as secondary closing edges, which typically cover a smaller distance (at a lower speed) when the closure body moves. As

Opposite closing edges are called edges which typically run opposite and / or parallel to the main closing edge.

A secondary closing edge attaches when the closing body moves

typically (at the lowest speed) the shortest distance back.

The data processing and control device can be any

Be a processor which is appropriately configured by means of a computer program to carry out the necessary tasks relating to data processing and control. The data processing and control device can thus be implemented by means of software and by means of one or more special electronic circuits, i.e. in hardware. The

The data processing and control device can be implemented logically and / or in terms of equipment by means of a common processor or function block or by means of several processors or function blocks. Also one

Realization in any hybrid form, ie using software components and hardware components, is possible. A closing body can be a door or a gate, for example. The following types of doors or gates can be monitored with the described sensor system. The following list is not exhaustive.

(a) Swing doors / gates: These are locking bodies with one or two leaves that rotate around a vertical axis on a leaf edge.

(b) Sliding doors / gates: These are closure bodies with one or more horizontally moving door leaves that move in their own plane over an opening or passage.

(c) Folding wing doors / gates: These are closing bodies with two or more wings that are hinged to one another and where one side of the wing is connected to a frame.

(d) Revolving doors: These are closing bodies with two or more

Door leaves that are connected on a common vertical axis of rotation within an enclosure.

(e) Roller doors: These are closing bodies with a flexible wing that is moved vertically and, when opened, is wound onto a winding shaft.

(f) Sectional doors: These are closing bodies with a non-rigid wing, which is made up of a number of typically horizontally interconnected

Sections and is usually raised vertically when opening. The way in which the sash is put down in the upper opening position depends on the type (e.g. horizontal, vertical, folded).

(g) Up-and-over doors: These are locking bodies with a rigid wing which, when actuated, executes a tilting movement and remains in an upper horizontal distortion when fully opened.

(h) Sliding gates: These are closure bodies with one or more leaves that are moved horizontally.

According to one embodiment of the invention, in the first

Operating mode at least a part of the scene can be detected with greater spatial accuracy than in the second operating mode. The accuracy can depend on the intensity of the illumination by the illumination light and / or from the the spatial resolution of the measuring device.

In this context, a greater illumination intensity ensures better illumination so that objects can be better recognized. A higher spatial resolution typically requires a higher energy consumption because a certain minimum number of photons must be accumulated per pixel of a sensor chip in order to produce a

to get sensible evaluable sensor signal. In the case of a smaller spatial resolution, several typically neighboring pixels can also be combined via what is known as “binning” to form a superordinate pixel with a correspondingly increased number of accumulated photons.

According to a further exemplary embodiment of the invention, the sensor system is configured to record the scene with a time sequence of scene recordings, the number of which is within a predetermined time period

Scene detection in the first operating mode is greater than in the second operating mode. This means that a (mean) time resolution or a (mean) repetition rate is greater in the first operating mode than in the second operating mode. In this context it is obvious that every single scene capture requires a certain amount of energy, so that with a smaller temporal resolution the energy consumption of the

Sensor system is reduced accordingly.

According to another embodiment of the invention, the second

Operating mode an idle state of the lighting device and / or the measuring device. The idle state can be a so-called standby state or "sleep mode".

In the idle state, the sensor system can, apart from monitoring an event that causes a transition to the first (active)

Operating mode initiated, no function carried out. Monitoring can but also have a reception of a wake-up signal, which (from the data processing and control device) from an external

Monitoring unit is received.

According to a further exemplary embodiment of the invention, the spatial area comprises a first partial area and a second partial area, the second partial area being at least partially different from the first partial area. The two spatial sub-areas can be spatially separated from one another or have a certain spatial overlap.

In preferred embodiments, the two spatial sub-areas are assigned different tasks or hazard potentials. The first spatial sub-area can be, for example, the immediate movement area of the closure body, in which a collision between an object and the closure body is possible. This sub-area can also be used as a

Hazardous area or as a safety area. The second sub-area can be that area in which objects are recognized that may be moving in the direction of the passage. The detection of such objects can then, depending on the application, lead to the

Closing body is moved from its open position to its closed position or vice versa. Such a second sub-area can also be called

Activation area are designated.

In this regard, it should be noted that for the two

Tasks "security" and "activation", which require a scene detection in different spatial areas, typically two different types of sensors are used up to now. For the job

"Activation" are, for example, radar sensors, 3D sensors or

Thermal imaging cameras used. Be for the "security" task

for example, contact strips or light barriers are used. In contrast, the solution described here uses a single type of 3D sensor used to cover both sub-areas. This means that the tasks of "security" and "activation" are not performed by two different types of sensors. This represents a further advantage in terms of the lowest possible energy consumption.

According to a further exemplary embodiment of the invention, the spatial extent and / or the spatial position of at least one of the two spatial subregions in the first operating mode is different from the spatial extent and / or the spatial position in the second operating mode. Expressed clearly, this means that a spatial division (with or without overlap) of the two spatial subregions depends on the operating state of the closure body. Through such a dynamic spatial division, the energy saving measure can be carried out in a more targeted manner and thus contribute to an even better energy saving.

The dynamic division can go so far that in either of the two

Operating modes the size of a sub-area is zero. This means that there is then no spatial division into (at least) two sub-areas. Such a "shrinkage to size zero" can be useful when the closure body is at rest, preferably in its closed position. In this case, there is generally no need to worry about a collision with an object, because the closing body can only move in the direction of its opening position. In the other of the two operating modes, the entire spatial area is in

(at least) divided into two sub-areas.

According to a further embodiment of the invention, the

Sensor system furthermore to an adaptive optical device for changing the spatial area. The data processing and control device is set up in such a way that the spatial area differs from the current

Operating mode depends. The size, the shape and / or the spatial position of the spatial area can depend on the current operating mode depend. With a dynamic-optical variation of the spatial area in which the scene is captured, depending on the operating status of the

Closing body, a further energy saving can be realized.

It should be noted that the adaptive optical device can also be used to divide the entire spatial area into two spatial sub-areas as described above, depending on the

Make the operating state of the sealing body.

The adaptive optical device can have an adaptive optics such as a deformable refractive lens or a diffractive optical element (DOE). Such adaptive optics can be assigned to the lighting device and / or the measuring device. A plurality of adaptive optics that can optionally be activated independently of one another can also be used. Of course, such adaptive optics can also be combined with other non-adaptive optics that cannot be changed over time

Elements are combined.

The term diffraction (or diffraction) in this context generally refers to the spatial deflection of an electromagnetic wave at structural obstacles. Such obstacles can be an edge, a hole or a one-dimensional, a two-dimensional or even a three-dimensional grid. The DOE can advantageously allow a dynamic adaptation or adaptation of the lighting characteristics during the operation of the sensor system.

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

Refractive index n of a medium is described. According to a further exemplary embodiment of the invention, the sensor system also has a data output for outputting a

Output signal which is used for a future operating state of the

Closing body is indicative.

The output signal can in particular from the data processing and

Control device are generated, which based on a

automatic image evaluation controls the closure body in a suitable manner. For example, certain objects can be passed through the

Passage is denied and other objects are allowed through the passage. Such a distinction can be made by automatic image evaluation with regard to the type and / or the identity of an object.

According to a further embodiment of the invention, the

Data processing and control device configured, at least two carried out at a certain time interval from one another

Evaluate scene captures together, using the number of photons accumulated in both scene captures in a pixel. This can increase the sensitivity to light (at the expense of time resolution). This means that even with a comparatively low intensity of the illuminating light, clear images of the scene (with a sufficient signal-to-noise ratio) can still be captured. In other words, by appropriately reducing the lighting intensity of the

Energy consumption of the sensor system can be further reduced.

It should be noted that, of course, more than two

Scene captures can be combined with one another. The number of scene captures that are processed together can depend on the required time resolution. This means that for objects that only move comparatively slowly, the number of jointly evaluated scene captures can be larger than with

Objects that move faster.

According to a further embodiment of the invention, the

Measuring device comprises (a) a light receiver with a plurality of pixels for receiving the measurement light and (b) a light receiver control device coupled to the light receiver, the light receiver control device and the light receiver being configured such that at least two pixels of the plurality of pixels are summarized in a parent pixel.

Typically, at least some of the plurality of pixels are combined in such a way that in each case a certain number of pixels are combined to form a superordinate pixel. The certain number can be, for example, (preferably) two, three, (preferably) four, six, (preferably) eight, or (preferably) nine. Of course, an even stronger grouping of pixels is also possible.

Such a grouping of pixels, which is also referred to as "binning", has the effect that, at the expense of spatial resolution, the number of photons of the measurement light that are collected or accumulated by a pixel during a scene detection increases according to the number is increased to a parent pixel combined pixels. As a result, the so-called statistical is reduced, especially with weak measuring light

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

It is pointed out that binning can also be carried out locally over the area of the light receiver in only at least a partial area of the active areas of the light receiver. This then leads to an inhomogeneous spatial resolution, which is not absolutely desirable. The The disadvantage of such an inhomogeneous spatial resolution is, however, overcompensated in many applications by the increased photon accumulation. A local "binning" can take place at least with 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 carried out in such a way that, measured by the measuring device and / or learned by the data processing and control device, precisely those areas of the light receiver that were used in at least one previous

Scene detection have received too little light energy, by suitable control of the light receiver by the light receiver control device, can be combined in a suitable manner into superordinate pixels during subsequent scene detections. Such a dynamically controlled or regulated "binning" can be (learned) during normal operation of the sensor system and / or during the configuration of the sensor system, for example in the context of (initial) installation, maintenance, cyclical or

automatic reconfiguration etc. can be carried out.

It is also pointed out that with a non-square number of individual pixels combined to form a superordinate pixel, the spatial resolution of the light receiver is different along different directions if the individual pixels have a square shape. This can be used to advantage in some applications. Such an application is, for example, when a movement of an object in the scene along a previously known spatial direction is to be detected with high accuracy than a movement along another spatial direction, preferably perpendicular thereto. In such a case, the number of pixels which are located along a line parallel to this previously known spatial direction (as shown on the light receiver is shown) are arranged, be larger than the number of pixels, which are arranged along a line perpendicular thereto. Then the spatial resolution along the direction of movement is greater than the spatial resolution perpendicular to the direction of movement and the movement profile of such a linearly moving object can be determined with a particularly high degree of accuracy even with a comparatively weak measuring light.

It is also pointed out that the described binning can also be adapted adaptively in response to at least one previously recorded (and evaluated)

Scene characteristics can be activated (automatically). This means that the "binning" is not only controlled by the light receiver control device but is regulated as a function of the results obtained through a scene evaluation. This makes a particularly reliable one

Enables scene detection even with weak measurement light, so that the sensor system described can also be used with a correspondingly weak one

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

According to a further embodiment of the invention, the

Lighting device on (a) designed as a laser

Illumination light source for spatial scanning of the scene with a

emitted laser beam illuminating light, (b) an at least approximately point-shaped illuminating light source, (c) a plurality of individual

Illumination light sources, which are in particular individually controllable and each assigned to a specific solid angle range of the scene, and / or (d) a flat illumination light source, in particular with a light intensity that is not homogeneous over the area.

A laser beam that scans the scene can be directed in a known manner via two rotatable mirrors with axes of rotation that are not parallel to one another and preferably oriented perpendicular to one another to the point of the scene to be illuminated. For such a (dynamically adaptive) distraction you can also non-mechanical optical elements such as diffractives

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

The at least approximately point-shaped illumination light source can be a (sufficiently strong) semiconductor diode, for example a laser or light-emitting diode. In order to specifically illuminate the scene over a large area, suitable

Beam shaping systems, in particular lens systems, are used. In order to achieve the uneven lighting of the scene depending on the spatial angle, suitable optical elements for beam deflection,

Beam splitting and / or beam merging can be used. DOEs can also be used to advantage.

The plurality of illumination light sources, which are likewise in particular lasers 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 setting of the characteristics of the illuminating light.

A flat light source can also be the source for an intensity distribution that is not homogeneous as a function of the spatial angle. If it is a spatially homogeneously illuminated surface, suitable optical elements can be used

Beam deflection, beam splitting, beam merging and / or beam shaping can be used in order to achieve the described non-uniform illumination of the scene as a function of the spatial angle.

According to a further embodiment of the invention, the

The data processing and control device is further configured in such a way that a coverage characteristic of the passage can be controlled by at least one closure body. This allows the opening, which for example is an entrance (or an exit) of a building can be automatically monitored in an energetically favorable manner, and the closing body can be automatically moved between an open position and a closed position by means of a suitable control of an actuator. The

Data processing and control device of the described

Sensor system can be coupled to the control of a known control system for a closure body.

According to a further aspect of the invention, a method is described for three-dimensional detection of a scene in a predetermined spatial area which is assigned to a closure body for a passage. The method described comprises (a) illuminating the scene with

Illuminating light by means of a lighting device; (b) receiving measurement light, which is at least partially backscattered illumination light from at least one object contained in the scene, by means of a

Measuring device;

Measuring distances between the sensor system and the at least one object based on a light transit time of the illuminating light and the

Measuring light by means of the measuring device;

Determining a three-dimensional characteristic of the scene based on the measured distances by means of a data processing and control device connected downstream of the measuring device;

Receiving an input signal at a data input, which is indicative of a current operating state of the closure body;

Operating the lighting device and / or the measuring device in a first operating mode with a first energy consumption when the closure body is in a first operating state; and

Operating the lighting device and / or the measuring device in a second operating mode with a second energy consumption when the closure body is in a second operating state, the second energy consumption being less than the first energy consumption. The method described is also based on the knowledge that the provision of different operating modes, each with different energy consumption, results in the overall energy consumption (over a longer

Operating time) can be reduced if due to the (expected)

Characteristic of the scene the requirements for the accuracy of the

Scene capture just isn't that high. The second operating mode can deliver (second) scene acquisitions which, compared to (first) scene acquisitions, have, for example, a lower temporal resolution, a lower spatial resolution and / or a lower signal-to-noise ratio.

According to a further exemplary embodiment of the invention, the method further comprises (a) detecting an object located in the scene; (b) a comparison of the detected object with at least one comparison object stored in a database; and (c) if the object matches a comparison object within predetermined permissible deviations

Identifying the object as an object allowed for a particular action.

The permitted action can be, for example, a permitted passage through an opening in a building, which opening is closed by a locking body before identification as an approved object and only after successful identification by a corresponding movement of the

Closing body is opened. The objects to be identified can preferably be people and / or vehicles. Successful identification can be for controlling or activating a locking mechanism for a locking body in front of a passage or opening of a building.

According to a further aspect of the invention, a use of a sensor system of the type described above for controlling a coverage characteristic of a passage to be passed by an object by at least one closure body is described. The described use is based on the knowledge that an energetically efficient detection and evaluation of an optical scene can be used in an advantageous manner for passages which can be closed by a closure body. This applies in particular to passages which have a closure or a covering characteristic that is controlled or at least also controlled by the described sensor system.

The inventive use of the above

Sensor system can also be monitored in an energetically efficient manner, even larger distances, which naturally leads to an earlier detection of a

Opening request of the closure body leads, which can be of great advantage, especially with fast-moving objects. Furthermore, the scene can be captured with a wider capture angle, which, for example, leads to an early detection of people moving across the opening

Cross traffic and thus can lead to more reliable detection of objects in a hazardous area.

According to an exemplary embodiment of the invention, the opening is an entrance or an exit, in particular an emergency exit in a building. By the

Detection of an existing but possibly not moving object in a passage area can monitor an input or output,

in particular a blocked emergency exit is detected, and the corresponding

Information to an affiliated system, for example to a

Monitoring system.

According to a further exemplary embodiment of the invention, the object is a person or a vehicle. In this case, the building can in particular be a house or a garage. It should be noted that embodiments of the invention have been described with reference to different subjects of the invention. In particular, some embodiments of the invention with device claims and other embodiments of the invention with method claims or

Use claims described. However, when reading this application, it will immediately become clear to the person skilled in the art that, unless explicitly stated otherwise, in addition to a combination of features belonging to a type of subject matter of the invention, any combination of

It is possible to have characteristics that lead to different types of

Subjects of the invention belong.

Before exemplary embodiments of the invention are described at a later point and with reference to the drawing, some technical considerations related to the invention are presented at this point.

TOF-based sensor systems can generally be used in relation to the

Illumination light as well as in relation to the measurement light can be divided into two fundamentally different classes, which can be combined with one another as required.

Bl: The first alternative (Bl) for the lighting is characterized in that the scene is higher by means of a single illuminating light beam

Focusing and low divergence (ie high collimation) is scanned sequentially. For each position of the illuminating light beam in the scene, a measurement of the transit time of the illuminating light and the measuring light is made

performed. The scanning can be implemented 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 a solid can be used, which manages without mechanically moving parts and integrated photonic structures or having circuits. With a suitable control of these structures, the illuminating light beam is then directed to the desired location in the scene. Such a solid is known, for example, from US 2015/293224 A1.

B2: The second alternative (B2) for the lighting is characterized by the fact that the entire scene is illuminated (all at once and over an area). If necessary, the intensity of the illuminating light can be increased (selectively) in selected sub-areas of the scene in order to enable improved 3D object detection at these points. Such a spatially uneven distribution of the intensity of the illuminating light can be achieved without moving optical

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

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

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

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

specified frequency, with suitable 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 the distance information is derived from it.

Both measuring principles M1 and M2 are based on an integration of the number of photons or the photoelectrons generated in the light receiver, which arrive at each pixel to be measured. In this context, it is obvious that light or photon noise that is always present depends on the number of photons accumulated in a pixel. Hence the out The distance information obtained from the TOF measurement is more accurate the higher the number of accumulated photons.

Further advantages and features of the present invention emerge from the following exemplary description of currently preferred embodiments.

Brief 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.

FIG. 2 illustrates a variation in the size of a spatial region in which a scene is recorded by means of an adaptive optical device.

Figures 3a and 3b illustrate a combination of individual pixels for

Increase in the light sensitivity of a light receiver.

Detailed description

FIG. 1 shows the use of a sensor system 100 for controlling a coverage characteristic of an opening or passage 184 depending on the characteristic of a scene 190 monitored by the sensor system 100. According to the exemplary embodiment shown here, the opening 184 is a

Entry opening for people into a building or a garage entrance for motor vehicles. The corresponding input structure is provided with the reference number 180. An object 195 located in the scene is intended to symbolize such a person or a motor vehicle. The entrance structure 180 comprises a stationary holding structure 182 which has a frame and a guide for two designed as sliding doors

Closing body 186 represents. The sliding doors 186 can each be opened by means of a motor 187 along the lines shown by two thick double arrows

Displacement directions are moved. The control of the motors 187 takes place, as set out below, by means of a data processing and

Control device 150 of the sensor system 100 described in this document.

According to the exemplary embodiment shown here, an operating state of the two sliding doors 186 is recorded by means of an encoder 188 each, which compared to the respective motor 187 represents a separate unit. In other embodiments, the encoder can also be integrated in the respective motor 187. In addition, the function of the encoder can also be dependent on the

Data processing and control device 150 are taken over.

The operating state of the sliding doors 186 can be the current position of the sliding doors 186 and / or the current speed at which the sliding doors 186 move from an open position to a closed position or vice versa from the closed position to the open position.

The sensor system 100 has a time of flight (TOF) measuring device 110, the data processing and control device 150 and a database 160.

The TOF measuring device 110 in turn has an illumination device 130 and a light receiver 120. According to the one shown here

The TOF measuring device 110 has or are assigned to 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 transit time between emitted by the lighting device 130 Illumination light 131 and measurement light 196 received by light receiver 120 after scattering on object 195 and (iii) a light receiver control device 140 for controlling the operation or for selecting an operating mode of light receiver 120.

In the TOF measuring device 110, all optical components of the

Sensor system 100 housed. The entire sensor system 100 (in contrast to the illustration in FIG. 1) is preferably constructed as a module which, within a compact design, not only has the TOF measuring device 110, but also the data processing and control device 150 and the database 160.

During operation of the sensor system, the data processing and controls

Control device 150 the two motors 187. One required for this

Electric power for actuating the doors 186 is provided in each case by an output stage or an amplifier which, according to the exemplary embodiment shown here, is integrated in the housing of the respective motor 187. The two output stages are each controlled via a signal 152a, which is output at a data output 152 by the data processing and control device 150 and is therefore referred to in this document as output signal 152a.

In accordance with the invention described in this document, the operating state of the doors 186 has at least a certain influence on the operation of the TOF measuring device 110. Specifically, this operating state determines the operation of the lighting device 130 and the operation of the

Light receiver 120 (with). This influence manifests itself in two operating modes of the TOF measuring device 110. In a first operating mode, they have

Sensor system 100 and in particular the TOF measuring device 110 and further in particular the lighting device 130 and / or the light receiver 120 a first energy consumption. In a second operating mode, they have Components have a second energy consumption, which is lower compared to the first energy consumption.

The operating state of the doors 186 is transmitted to one of the two encoders 188 by means of a data signal or a sequence of data signals

Data input 151 of the data processing and control device 150

transmitted. This data signal is used in this document from the point of view of

Data processing and control device 150- also referred to as input signal 151a. According to the embodiment shown here, the data processing and control device 150 processes this input signal 151a in a suitable manner and controls, inter alia. depending on this input signal 151a, the illumination light control device 135 and the light receiver control device 140 in such a way that an operating mode is established which (also) determines the energy consumption of the illumination device and / or the light receiver 120.

According to the exemplary embodiment shown here, the first operating mode with the higher energy consumption is activated when the two doors 186 are moved, in particular from their open position to their closed position. The second operating mode with the lower energy consumption is activated when the two doors 186 are at rest.

The scene 190 is captured in a spatial area which comprises a first partial area 191 and a second partial area 192. The first sub-area 191 is a so-called hazard area. If there is an object in this hazard area 191, there is basically the risk that it will be trapped and possibly injured when the doors 186 are closed. The sensor system 100 is therefore configured in such a way as to basically detect this hazardous area 191 with a very high degree of accuracy. For this purpose, a correspondingly bright illumination is provided in a first operating mode

Hazardous area 191 as well as detection with a high degree of accuracy required. In this context, it is obvious that this requires a relatively large amount of energy. However, if the doors 186 do not move, then there is no risk of an object being trapped or injured. It is therefore completely sufficient in a second operating mode if the hazard area 191 is illuminated by the lighting device 130 with a lower intensity and / or if the light receiver 120 detects the hazard area 191 with a reduced accuracy.

According to the exemplary embodiment shown here, the second partial area 192 is an area in which objects are detected so that the doors 186 can be moved in a suitable manner. The second sub-area 192 is therefore referred to as the activation area 192 in this document. The activation area 192 is generally not safety-relevant (with regard to a collision of a door 186 with an object). Therefore, in the embodiment described here, the activation area 192 is only ever operated, regardless of the operating state of the doors 186, that at the expense of the accuracy of the

Scene detection is given the best possible energy efficiency.

According to the exemplary embodiment shown here, the sensor system 100 is able to carry out an object detection. The

Data processing and control device 150 to a data record of reference objects stored in the database 160 which correspond to selected objects that are authorized to pass through the passage or opening 184. This means that when the object 195 appropriately approaches the entrance 184, the sliding doors 186 are only opened when the detected object 195 at least approximately matches one of the stored ones

Reference objects. This clearly means that when using the sensor system 100 described here, an object-based

Access control takes place. FIG. 2 illustrates an embodiment in which the size of the spatial area detected by the light receiver 120 depends on the operating state of the closure body. This is done according to the one shown here

Embodiment implemented by means of an adaptive optical device which can assume two spatial configurations 221a and 221b. The adaptive optical device is shown schematically by means of a deformable optical lens. In a first operating mode, a comparatively small sub-area 291a of the scene is recorded with a particularly high level of accuracy (high spatial and / or temporal resolution, large signal-to-noise ratio, etc.). For this purpose, the adaptive optical device assumes the first configuration 221a (with a small focal length). In a second

In the operating mode, a comparatively large sub-area 291b of the scene is recorded with reduced accuracy. For this purpose, the adaptive optical device assumes the second configuration 221b (with a large focal length).

The adaptive optical device can be realized with any desired element with which imaging properties can be changed dynamically. For example, the adaptive optical device can have a plurality of lenses with different focal lengths that can be displaced along an axis or one objective with a variable focal length. The use of at least one DOE is also possible in order to enable a corresponding variation of the optical imaging of the sub-area 291a / 291b on a light-sensitive chip of the light receiver 120.

It should be noted that the one not shown

Illumination device emitted light quantity is of course best used when the area of the scene which is detected by the light receiver 120 is exactly the same area as that of the

Lighting device is illuminated. Accordingly, it is advantageous if at least one second adaptive optical device is provided, which is assigned to the lighting device. FIGS. 3a and 3b illustrate a combination of individual pixels of a light receiver 320a or a light receiver designed as a semiconductor or CCD chip.

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

Photon collecting pixels 322a. According to the one shown here

In the exemplary embodiment, the pixels 322a are assigned to a 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 associated with a higher-level pixel 322b (for an increased

Photon accumulation per pixel at the expense of a reduced spatial

Resolution). In illustrative terms, a pixel 322b collects four times the amount of light compared to a single pixel 322a. Such a combination (English "binning") reduces the required

(Minimum) intensity of the recorded measurement light, which is required to evaluate the corresponding image area of the scene. Since the intensity of the measuring light depends directly on the intensity of the illuminating light, the intensity of the illuminating light can be reduced through the "binning" and thus the energy consumption of the sensor system can be reduced.

According to the embodiment shown here, this is described

"Binning" as a function of the operating state of the not shown

Closing body realized by a corresponding control of one and the same light receiver 320a or 320b. The light receiver is operated either in a first operating mode (with full resolution) or in a second operating mode (with combined photon-collecting pixels).

It should be noted that more than two different

Operating modes, each with a combination of pixels of different strengths, can be used. It is also possible in different Subareas of the light receiver each combine a different number of individual pixels to form a superordinate pixel. Then individual sub-areas of the scene with a higher spatial resolution (and a lower photon accumulation) and other sub-areas of the scene with a lower spatial resolution (and a higher

Photon accumulation). The local and

In addition, different levels of grouping of pixels can be carried out not only as a function of the operating state of the closure body but also dynamically or adaptively in precisely those partial areas in which a certain object is currently located.

It is noted that the term “having” does not exclude other elements and that the “a” does not exclude a plurality. Elements that are described in connection with different exemplary embodiments can also be combined. It should also be noted that any reference signs in the claims should not be construed as limiting the scope of the claims.

REFERENCE MARK:

100 sensor system

110 TOF measuring device

120 light receivers

125 measuring unit

130 lighting device

131 illumination light

135 Illumination light control device 140 Light receiver control device

150 data processing and control device

151 Data input

151a input signal

152 data output

152a output signal

160 database

180 entrance structure

182 stationary support structure

184 opening / passage

186 locking body / sliding door

187 engine M

188 Encoder E

190 scene

191 first part

192 second part

195 object

196 measuring light a adaptive optical device (first state) b adaptive optical device (second state) a partial area with first size

b Partial area with second size a / b light receiver / sensor chip

a pixel

b parent pixel / pooled pixel

Claims

Patent claims

1. Sensor system (100) for three-dimensional detection of a scene (190) in a predetermined spatial area which is assigned to a

Closure body (186) for a passage (184), having the sensor system (100)

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

a measuring device (110)

for receiving measurement light (196) which is at least partially backscattered from at least one object (195) contained in the scene (190)

Illuminating light (196) is, and

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

Illuminating light (131) and the measuring light (195);

a data processing and control device (150) connected downstream of the measuring device (110) for determining a three-dimensional

Characteristic of the scene (190) based on the measured distances; and a data input (151) for receiving an input signal (151a) which is indicative of a current operating state of the closure body (186);

wherein the lighting device (130) and / or the measuring device (110) can be operated in a first operating mode with a first energy consumption and in a second operating mode with a second energy consumption which is smaller than the first energy consumption.

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

in the first operating mode, at least part of the scene (190) can be captured with greater spatial accuracy than in the second

Operation mode.

3. Sensor system (190) according to one of the preceding claims, wherein the sensor system (190) is configured to detect the scene (190) with a time sequence of scene acquisitions, wherein within a

predetermined period of time the number of scene acquisitions in the first operating mode is greater than in the second operating mode.

4. Sensor system (100) according to one of the preceding claims, wherein the second operating mode is an idle state of the lighting device (130) and / or the measuring device (110).

5. Sensor system (100) according to one of the preceding claims, wherein the spatial area has a first partial area (191) and a second

Sub-area (192), the second sub-area (192) being at least partially different from the first sub-area (191).

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

of at least one of the two sub-areas (191, 192) the spatial

Expansion and / or the spatial position in the first operating mode is different from the spatial expansion and / or the spatial position in the second operating mode.

7. Sensor system (100) according to one of the preceding claims, further comprising

an adaptive optical device (221a, 221b) for changing the spatial area, the data processing and control device (150) being set up in such a way that the spatial area depends on the current operating mode.

8. Sensor system according to one of the preceding claims, further comprising a data output (152) for outputting an output signal (152a) which is indicative of a future operating state of the closure body (186).

9. Sensor system (100) according to one of the preceding claims, wherein the data processing and control device (150) is configured to have at least two at a certain time interval from one another

jointly evaluate performed scene acquisitions, the number of photons accumulated in both scene acquisitions in a pixel (322a) being used.

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

a light receiver (120; 320a, 320b) having a plurality of pixels (322a) for receiving the measuring light (196) and

one coupled to the light receiver (120; 320a, 320b)

Light receiver control device (140), the light receiver control device (140) and the light receiver (140) being configured in such a way that at least two pixels (322a) of the plurality of pixels (322a) are combined to form a superordinate pixel (322b).

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

(a) an illumination light source designed as a laser for spatially scanning the scene with an emitted laser beam illumination light (131),

(b) an at least approximately point-shaped illuminating light source,

(c) a plurality of individual illumination light sources, which in particular can be individually controlled and are each assigned to a specific solid angle range of the scene, and / or

(d) a planar illumination light source, in particular with a light intensity that is not homogeneous over the area.

12. Sensor system (100) according to one of the preceding claims, wherein the data processing and control device (150) is further configured such that a coverage characteristic of the passage (184) can be controlled by at least one closure body (186).

13. A method for three-dimensional acquisition of a scene (190) in a predetermined spatial area which is assigned to a

Closure body (186) for a passage (184), comprising the method

Illuminating the scene with illuminating light (131) by means of a

Lighting device (130);

Receiving measuring light (196), which is at least partially backscattered illumination light (131) from at least one object (196) contained in the scene (190), by means of a measuring device (110);

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

Illuminating light (131) and the measuring light (196) by means of the measuring device (110);

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

Receiving an input signal (151a) at a data input (151) which is indicative of a current operating state of the closure body (186);

Operating the lighting device (130) and / or the

Measuring device (110) in a first operating mode with a first

Energy consumption when the closure body (186) is in a first

Operating status is located; and

Operating the lighting device (130) and / or the

Measuring device (110) in a second operating mode with a second energy consumption when the closure body (186) is in a second operating state, the second energy consumption being less than that first energy consumption.

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

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

Comparing the detected object (195) with at least one in one

Database (160) stored comparison object; and,

if the object (195) matches a comparison object within predetermined permissible deviations, identifying the object (195) as an object (195) that is permitted for a specific action.

15. Use of a sensor system (100) according to one of the preceding claims 1 to 12 for controlling a coverage characteristic of a passage (184) to be passed by an object (195) by at least one closure body (186).

16. Use according to the preceding claim, wherein

the passage (184) is an entrance or an exit, in particular a

Emergency exit in a building.

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