Patent Publication Number: US-2023134584-A1

Title: Security strip for a door and method of operating a security strip

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to European Application Number EP21206246.7 filed Nov. 3, 2021, the disclosure of which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The invention concerns a safety strip for a door, in particular for a door of a means of transport. Furthermore, the invention concerns a door with a safety strip and a means of transport with that door. Furthermore, the invention concerns a method for operating a safety element. 
     TECHNICAL BACKGROUND 
     Safety strips for doors of means of transport are known from prior art. The safety strips serve as a seal between a door and a frame, or between two doors. Safety strips can also be called profiled safety strips. Furthermore, safety strips can prevent objects, e.g., people or things, from getting caught between the door and the frame, or between two doors, or reduce the probability of getting caught. To this end, safety strips can, e.g., comprise a contact strip that generates a signal when the safety strip is deformed in a predefined way. Such deformation of the safety strip can be caused, e.g., by a person&#39;s arm being caught between the closing door and the frame, or between two doors. The signal can be used to stop the further closing of the door to prevent injury to the person. 
     In addition, the use of light curtain arrangements is known which allow detection of an object between the door and the frame, or between two doors. Frequently, a light curtain arrangement comprises a transmitting unit and a receiving unit. The transmitting unit can be provided in the frame, and the receiving unit can be provided in the door. When reception of the light emitted by the transmitting unit is interrupted by an object, the light curtain arrangement can generate a signal allowing the closing of the door to be stopped. 
     The detection of objects by means of contact strips and/or light curtain arrangements is limited with respect to several aspects. In addition, in particular the transmitting unit and the receiving unit of the light curtain arrangement are open in the direction of the monitored space, which makes them susceptible to damage, e.g., due to vandalism. 
     SUMMARY OF THE DISCLOSURE 
     Therefore, the task of the invention is to provide a safety strip that improves the detection of objects. A further task of the invention is to provide a safety strip that guarantees improved safety. Another further task of the invention is to provide a safety strip that affords protection against damage. Another further task of the invention is to provide a safety strip that can be manufactured and/or exchanged easily and cost efficiently. 
     At least one of the tasks is solved by the items of the independent claims. Further embodiments of the invention are defined in the dependent claims. 
     Shown is a safety strip for a door, preferably for a door of a means of transport. The safety strip is elastic and/or flexible. The safety strip has at least one receiving space. The safety strip comprises a sensor arrangement. The sensor arrangement is set up to emit electromagnetic radiation into a monitored area and to receive such radiation from the monitored area. The sensor arrangement is arranged in the receiving space in such a way that the safety strip completely encloses the sensor arrangement at least in one plane. 
     The emission of electromagnetic radiation into the monitored space and the reception of electromagnetic radiation that exits from the monitored space allow good monitoring of the monitored space, and detection of objects within the monitored space is improved. The sensor arrangement can be arranged in the receiving space in such a way that it is protected. Furthermore, the sensor arrangement can be affixed simply to a door, e.g., to a door of a means of transport. To do this, it is only necessary to replace the safety strip of the door. This provides a simple and cost-efficient way to retrofit existing doors. 
     The safety strip can be non-rigid, flexible and/or elastic. In particular, the safety strip is designed as a profile, and is provided as a profiled safety strip. The safety strip can contribute to a sealing between the door and a frame, or between the door and a further door, or effect such sealing. 
     The safety strip can be intended for use on a movable element. For example, the safety strip is intended for use on a door or a window. 
     In general, the door can be a plug door, a revolving door, a folding door, a sliding door, a sliding plug door, an internal swing door or an external plug door. Likewise, the door can be set up for a building, or be installed in a building. 
     The means of transport can generally be a vehicle, preferably a commercial vehicle or a passenger vehicle. The means of transport can be a passenger car, a motor truck, a bus, a selfdriving vehicle or shuttle, or a train. The means of transport can be an elevator, an airplane, or a cabin, e.g., a ropeway cabin. 
     The safety strip can be set up to detect at least one object, e.g., a person or a thing, within the monitored space. Alternatively, or in addition, the safety strip can be set up to generate a signal when an object is detected in the monitored space. Based on the signal, e.g., a control of the door can be changed. 
     The monitored area or the monitored space can be an entrance and/or an exit area or space. The monitored area can, at least partly, be located within a means of transport and/or outside of a means of transport. The monitored area can have a volume of at least 0.01 m 3 , preferably at least 0.1 m 3 , preferably at least 0.5 m 3 , preferably at least 1.0 m 3 . 
     The monitored area can extend perpendicular to a plane defined by the door over a distance of at least 0.1 m, preferably at least 0.5 m, preferably at least 1.0 m, preferably at least 2.0 m, preferably at least 3.0 m. 
     The sensor arrangement can be a (single) unit. For example, the sensor arrangement can include a housing. All components of the sensor arrangement can be arranged within the housing. All components of the sensor arrangement can be arranged in the receiving space of the safety strip. The sensor arrangement can be a sensor. 
     The safety strip can be made of (only) one material. Alternatively, the safety strip can be made of several materials, e.g., of at least two different materials, or of at least three different materials. The safety strip can include an elastomer or a rubber. The safety strip can be made of an elastomer or a rubber. The safety strip can include, or be made of, different elastomers or different rubbers. For example, the safety strip can include, or be made of, silicone or an EPDM. 
     The safety strip can be opaque at least in sections, in particular entirely. The safety strip can be impervious to light in a wavelength range visible to humans (approx. 380 nm to approx. 780 nm) at least in sections, in particular entirely. For example, the safety strip is black. The safety strip can include a color additive, preferably carbon. 
     The safety strip can be produced, or be producible, by means of extrusion or coextrusion. 
     The sensor arrangement can emit electromagnetic radiation into the monitored area, the electromagnetic radiation can be reflected in the monitored area, e.g., by objects in the monitored space, and the reflected electromagnetic radiation can be received by the sensor arrangement. Due to the electromagnetic radiation, in particular due to the electromagnetic radiation received or reflected, the sensor arrangement can determine whether an object is located within the monitored area. 
     In general, the electromagnetic radiation can also be referred to as electromagnetic waves. 
     The electromagnetic radiation can be transmitted through the safety strip. Alternatively, or in addition, the electromagnetic radiation can be received through the safety strip. The electromagnetic radiation can pass through the material of the safety strip when it is received and/or transmitted. 
     The sensor arrangement can be arranged in the receiving space in such a way that the electromagnetic radiation passes through the safety strip, or the material of the safety strip, preferably if the electromagnetic radiation is received and/or transmitted through the sensor arrangement. 
     The sensor arrangement can be arranged in the receiving space in such a way that at least 25% of the surface of the sensor arrangement are enclosed by the safety strip, or the material of the safety strip. Preferably, the sensor arrangement is arranged in the receiving space in such a way that at least 35%, preferably at least 50%, more preferably at least 60%, more preferably at least 75%, more preferably at least 90%, more preferably at least 95%, more preferably at least 97%, more preferably at least 99% of the surface of the sensor arrangement are enclosed by the safety strip, or the material of the safety strip. 
     The sensor arrangement can be enclosed by at least one section of the safety strip, or of a material of the safety strip, through which electromagnetic radiation passes to be received and/or transmitted by the sensor arrangement. 
     The plane in which the sensor arrangement is completely enclosed by the safety strip can be oriented perpendicular to a plane that is defined by the door. The safety strip can completely enclose the sensor arrangement in multiple planes, e.g., in at least two planes, at least three planes, at least five planes, or at least ten planes. The multiple planes can be in parallel to each other, and the distance between them can preferably be at least 1 mm, 5 mm, or 10 mm. Alternatively, the multiple planes can be not in parallel to each other, and the angle between any two of the planes can be 5°, 10°, or 20°. 
     The safety strip, or the material of the safety strip, can essentially completely enclose the sensor arrangement. Due to the “essentially”, one or more of the data lines and/or power supply lines and/or the signal line can be excluded. The safety strip, or the material of the safety strip, can completely enclose the sensor arrangement, possibly with the exclusion of data lines, signal line and/or power supply lines. This means that data lines, signal line and/or power supply lines need not be (completely) enclosed by the safety strip if the sensor arrangement is completely enclosed by the safety strip. 
     The receiving space can be designed as a channel. The receiving space can be open at not more than two sides, preferably at not more than one side. An opening, or more than one opening, of the receiving space can be closed by a closing element. 
     The sensor arrangement can be a radar sensor arrangement. Radar stands for radio detection and ranging. 
     The sensor arrangement can be a continuous wave radar or a continuous wave radar sensor arrangement. The continuous wave radar can be modulated or unmodulated. Preferably, the sensor arrangement is an FMCW radar sensor arrangement or a CW radar sensor arrangement. FMCW stands for frequency modulated continuous wave. CW stands for continuous wave. The sensor arrangement can be set up to operate on the basis of FMCW or CW. 
     The sensor arrangement can be an M-sequence radar sensor arrangement. The sensor arrangement can be set up to operate on the basis of M-sequence. 
     The sensor arrangement can be a pulse modulation radar sensor arrangement. The sensor arrangement can be set up to operate on the basis of pulse modulation. 
     The sensor arrangement can be set up to emit radio-frequency electromagnetic radiation into the monitored area and/or to receive such radiation from the monitored area. 
     The frequency of the electromagnetic radiation can be between 30 kHz and 3000 GHz. Preferably, the frequency of the electromagnetic radiation is between 1 MHz and 3000 GHz, more preferably between 1 MHz and 300 GHz, more preferably between 6 MHz and 300 GHz, more preferably between 1 GHz and 300 GHz, more preferably between 59 GHz and 62 GHz. The frequency of the electromagnetic radiation can be between 1 GHz and 40 GHz. 
     The sensor arrangement can be set up to emit electromagnetic radiation into the monitored area with a power of less than 1.0 W. Preferably, the sensor arrangement is set up to emit electromagnetic radiation into the monitored area with a power of less than 100 mW, more preferably of less than 10 mW, more preferably between 0.1 mW and 10 mW, more preferably between 1 mW and 10 mW. 
     The sensor arrangement can be set up to emit and/or receive electromagnetic radiation within an ISM band (ISM: industrial, scientific, and medical band). An ISM band can be a frequency range that can be used by high-frequency units in industrial, scientific, medical, domestic and/or similar environments without a license, and in most cases without the need of approval. 
     The sensor arrangement can have at least one antenna. The antenna can be set up to emit electromagnetic radiation into the monitored area and/or to receive such radiation from the monitored area. Preferably, the antenna is set up to emit electromagnetic radiation into the monitored area and/or to receive such radiation from the monitored area. 
     The sensor arrangement can comprise at least a first antenna and at least a second antenna. The first antenna can be set up to emit electromagnetic radiation into the monitored area. The second antenna can be set up to receive electromagnetic radiation from the monitored area. The sensor arrangement can comprise at least a first antenna and at least two second antennae. 
     Preferably, the sensor arrangement comprises three antennae that are set up to emit electromagnetic radiation into the monitored area. Alternatively, or in addition, the sensor arrangement can comprise four antennae that are set up to receive electromagnetic radiation from the monitored area. 
     Each of the antennae can be set up to emit and receive electromagnetic radiation. Preferably, emission and reception have a time offset or a time lag. Alternatively, each of the antennae can be set up to only (i.e., exclusively) emit, or to only (i.e., exclusively) receive electromagnetic radiation. For example, first antennae can be set up to only (i.e., exclusively) emit electromagnetic radiation. Second antennae can be set up to only (i.e., exclusively) receive electromagnetic radiation. 
     The sensor arrangement can comprise at least two antennae that are set up to emit electromagnetic radiation. The two antennae can be arranged at a distance to one another within the sensor arrangement. The distance (also called transmitting antenna distance) can be between 0.6 and 1.5, preferably between 0.7 and 1.4, more preferably between 0.8 and 1.3, more preferably between 0.9 and 1.1, more preferably between 0.95 and 1.05, more preferably 1.0 times the wavelength of the electromagnetic radiation. The sensor arrangement can comprise at least three antennae that are set up to emit electromagnetic radiation. The transmitting antenna distance can be present between the first of the three antennae and the third of the three antennae. Alternatively, or in addition, the transmitting antenna distance can be present between the second of the three antennae and the third of the three antennae. 
     The sensor arrangement can comprise at least two antennae that are set up to receive electromagnetic radiation. The two antennae can be arranged at a distance to one another within the sensor arrangement. The distance (also called receiving antenna distance) can be between 0.1 and 0.9, preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.6, more preferably between 0.45 and 0.55, more preferably 0.5 times the wavelength of the electromagnetic radiation. The sensor arrangement can comprise at least four antennae that are set up to emit electromagnetic radiation. The receiving antenna distance can be present between the first of the four antennae and the third of the four antennae. Alternatively, or in addition, the receiving antenna distance can be present between the third of the four antennae and the fourth of the four antennae. Alternatively, or in addition, the receiving antenna distance can be present between the fourth of the four antennae and the second of the four antennae. Alternatively, or in addition, the receiving antenna distance can be present between the second of the four antennae and the first of the four antennae. The receiving antenna distance can be present in each case between any two of the four antennae. 
     The safety strip can have a fastening section. The safety strip can be connectable to the door non-positively and/or positively by means of the fastening section. The safety strip can be detachably connectable to the door. 
     The door can have a fastening receiver. The fastening receiver can be designed in such a way that the fastening section of the safety strip can be inserted into the fastening receiver to connect the safety strip to the door non-positively and/or positively. 
     The safety strip can comprise a contact strip, in particular an electrical contact strip. Alternatively, or in addition, the safety strip can comprise a light curtain arrangement. 
     The contact strip can output a contact signal that is used to control the light source. The contact strip can be arranged in a contact area of the safety strip with a frame, or in the contact area of the safety strip with another door. In this way, mechanical contact with the other door, the frame, or an object can easily be detected. The contact strip is preferably arranged in an enclosed hollow space, or receiving space, of the safety strip that causes output of the contact signal by the contact strip when that space is elastically deformed. 
     The light curtain arrangement can be set up to detect an object in the monitored area. The monitored area can be identical or different to the monitored area of the sensor arrangement. The light curtain arrangement can be set up to emit light, in particular light not visible to humans, into the monitored area and/or to receive such light from the monitored area. The light curtain arrangement can be arranged in a hollow space or a receiver in the safety strip. 
     The sensor arrangement, the contact strip and/or the light curtain arrangement can be linked to a door control system. The sensor arrangement, the contact strip and/or the light curtain arrangement can each be set up to generate a signal and transmit the signal to the door control system. Based on the one, or the multiple, signals, the control of the door, in particular the movement of the door, can be changed. 
     The length of the safety strip can be a multiple of its width. The multiple can be at least two, preferably at least five, more preferably at least ten, more preferably at least twenty. The sensor arrangement can be arranged at a distance of not more than 40%, preferably not more than 35%, more preferably not more than 30%, more preferably not more than 25%, more preferably not more than 20%, more preferably not more than 15%, more preferably not more than 10%, more preferably not more than 5% of the total length of the safety strip in longitudinal direction from an end of the safety strip. The longitudinal direction can extend along the lengthwise direction. 
     The safety strip can have a length of at least 0.5 m, preferably at least 1.0 m, more preferably at least 1.5 m, more preferably at least 2.0 m, 2.5 m. 
     Usually, the safety strip is installed, or installable, vertically (in the direction of gravitation) at the door. The sensor arrangement can be arranged in an upper area. A distance to the upper end of the safety strip can be no more than 40%, preferably not more than 35%, more preferably not more than 30%, more preferably not more than 25%, more preferably not more than 20%, more preferably not more than 15%, more preferably not more than 10%, more preferably not more than 5% of the total length of the safety strip. 
     The sensor arrangement can emit the electromagnetic radiation downward (in the direction of gravitation). Emission can be at an angle to the downward direction. 
     The safety strip can comprise a controller. The controller can be a control and/or evaluation unit. The controller can be set up to determine, on the basis of the electromagnetic radiation received, whether at least one object is located within the monitored area. In particular, the sensor arrangement includes the controller. 
     Alternatively, the controller can be arranged outside of the safety strip. The sensor arrangement can transmit signals to the controller on the basis of the electromagnetic radiation received. Based on the signals, the controller can determine whether an object is located within the monitored area. Transmission can be wireless or wire-bound. 
     The controller can be set up to edit, to process and/or to evaluate a signal which is based on the electromagnetic radiation received. The signal can comprise, or be, the totality of all variables obtained through the sensor arrangement. For example, the signal can comprise all variables received from the antennae. In particular, one or multiple filters can be applied to the signal. For example, a background signal can be deducted, or subtracted out, by a filter. 
     The editing may alter the signal. In particular, the signal is altered by the processing for the purpose of (downstream) further processing of the signal, or evaluation of the signal. 
     The controller can be set up to determine a location and/or a speed and/or a direction of movement of the object on the basis of the electromagnetic radiation received in the monitored area, or based on the edited, processed and/or evaluated signal. The speed can be a relative speed between the sensor arrangement and the object. The location can be ascertainable based on a distance between the sensor arrangement and the object, and a direction. The direction can be determined or defined by a point and one angle or two angles. 
     Preferably, the sensor arrangement or the controller are set up to determine both the location and the speed of an object located within the monitored space. In addition, the sensor arrangement or the controller can be set up to determine a direction of movement of the object. 
     The controller can be set up to resolve the signal, which is based on the electromagnetic radiation received, into intermediate information. The intermediate information can comprise a distance, an angle, a speed and/or a signal strength. Likewise, the intermediate information can comprise additional variables, in particular abstracted variables, which enable a classification of objects. 
     The controller can be set up to classify the object on the basis of the electromagnetic radiation and/or on the basis of the edited, processed and/or evaluated signal. Classes of the classification can include a type, a state and/or a relevance. Each of the classes can be subdivided into at least two subclasses. For example, the “type” class can be subdivided into [“person”, “door” ]. The “state” class can, e.g., be subdivided into [“moves towards door”, “moves away from door”, “does not move” ]. The “relevance” class can, e.g., be subdivided into [“relevant”, “not relevant” ]. 
     The controller can be set up to separate the object on the basis of the electromagnetic radiation and/or on the basis of the edited, processed and/or evaluated signal. For example, multiple objects can be identified by the controller on the basis of the electromagnetic radiation and/or on the basis of the edited, processed and/or evaluated signal. The controller can be set up to distinguish or separate the (identified) objects. 
     The controller can be set up to evaluate or analyze the signal which is based on the electromagnetic radiation received. For example, the controller can be set up to detect or determine or interpret a scenario on the basis of the signal which is based on the electromagnetic radiation received. 
     Preferably, the controller is set up to interpret the scenario on the basis of the signal, the intermediate information and/or the classification. For example, the controller can be set up to determine whether a person (also called a passenger) is approaching a door that is closing. Doing this, the controller can determine whether the person (probably) will be caught between the door and a frame, or between the door and a further door. 
     The controller can be set up to generate a signal on the basis of the electromagnetic radiation and/or on the basis of the edited signal and/or on the basis of the classification and/or on the basis of a state of the door. An operation of the door can be alterable due to the signal generated. Preferably, a movement of the door is alterable due to the signal. More preferably, a closing operation of the door is interruptible or abortable due to the signal. 
     Preferably, the state of the door, in particular the opening and/or closing state of the door, is an influencing variable during generation of the signal. When a person or any other object is moving towards a door that is closing, and the door is wide open, the controller can determine that abortion of the closing operation is not necessary. If, however, the door is open only a little, e.g. because the closing operation is almost completed, the controller can determine that the closing operation is to be aborted, because it is imminent, or there is a threat, that the person will be caught between the door and the frame, or the door and another door. 
     The controller can be set up to use an algorithm, or multiple algorithms, preferably before the signal is generated. In particular, the controller can be set up to use an algorithm, or multiple algorithms, to evaluate the signal which is based on the electromagnetic radiation. An algorithm can be set up to learn from data. For example, machine learning can be applied to the algorithm. In particular, supervised machine learning, unsupervised machine learning and/or reinforcement learning is applied to the algorithm. 
     Shown is a method for operating a safety strip for a door, in particular for a door of a means of transport. The safety strip comprises a sensor arrangement that is arranged within a receiving space of the safety strip and is completely enclosed by the safety strip at least in one plane. The method comprises the following steps: Emission, by the sensor arrangement, of electromagnetic radiation into a monitored space; reception, by the sensor arrangement, of electromagnetic radiation from the monitored space; and determination, on the basis of the electromagnetic radiation received, whether an object is located within the monitored space. 
     Any of the safety strips disclosed herein can be used in the method. In particular, any of the process steps disclosed herein, e.g., any process step for which the controller is set up, can be used in the method. 
     Shown is a door with a safety strip. The door can comprise any of the safety strips disclosed herein. 
     The safety strip can be detachably connected to the door. In particular, the safety strip is inserted into the door at least in sections. 
     The door can be a plug door, a revolving door, a folding door, a sliding plug door, an internal swing door or an external plug door. The door can be an automatic door, preferably a semi-automatic or a fully automatic door. The door can be driven, e.g., by a motor, preferably an electric motor. Likewise, the door can be drivable pneumatically or hydraulically. An opening and/or closing of the door can be effected by means of the drive. 
     Shown is a door arrangement. The door arrangement can comprise at least two doors. 
     Shown is a means of transport having at least one door. The means of transport can have two doors. Each of the doors can be any door disclosed herein. 
     The means of transport can generally be a vehicle, preferably a commercial vehicle or a passenger vehicle. The means of transport can be a passenger car, a motor truck, a bus, or a train. The means of transport can be an elevator, an airplane, or a cabin, e.g., a ropeway cabin. 
    
    
     
       SHORT DESCRIPTION OF THE FIGURES 
       In the following, the disclosure, or further embodiments and advantages of the disclosure, are explained in more detail with the help of figures, the figures only describing embodiments of the disclosure. Identical components in the figures have identical reference signs. 
         FIG.  1   a    shows a door arrangement in a first state; 
         FIG.  1   b    shows a door arrangement in a second state; 
         FIG.  2   a    shows a door arrangement in a first state; 
         FIG.  2   b    shows a door arrangement in a second state; 
         FIG.  3   a    shows a safety strip and a door in a non-connected state; 
         FIG.  3   b    shows the safety strip and the door in a connected state; 
         FIG.  4    shows a schematic diagram of a sensor arrangement; 
         FIG.  5   a    shows a door arrangement in a first state; 
         FIG.  5   b    shows a measurement by a sensor arrangement; 
         FIG.  5   c    shows a measurement by a sensor arrangement; 
         FIG.  5   d    shows a measurement by a sensor arrangement; 
         FIG.  6   a    shows a door arrangement in a first state; 
         FIG.  6   b    shows a measurement by a sensor arrangement; 
         FIG.  6   c    shows a measurement by a sensor arrangement; 
         FIG.  6   d    shows a measurement by a sensor arrangement; 
         FIG.  7   a    shows a door arrangement in a first state; 
         FIG.  7   b    shows a measurement by a sensor arrangement; 
         FIG.  7   c    shows a measurement by a sensor arrangement; 
         FIG.  7   d    shows a measurement by a sensor arrangement; 
         FIG.  8   a    shows a monitored area of a sensor arrangement; and 
         FIG.  8   b    shows a monitored area of a sensor arrangement, and a monitored area of a sensor arrangement. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1   a    shows a door arrangement  1000  in a first state. The door arrangement  1000  comprises a door  300 . The door  300  can be a door of a means of transport, e.g., of a train. The door  300  is a single-leaf design. The door  300  can be designed as a sliding door that closes against a frame  500 . The door  300  preferably comprises a safety strip  200  at a front side, that, when the door  300  touches the frame  500 , which e.g., is an aluminum or steel profile, is (slightly) compressed. The door  300  preferably has a glass or a windowpane  400 . The door  300  can define an X-Y-plane. A Z-direction can be oriented perpendicular to the X-Y-plane. 
     The safety strip  200  comprises a sensor arrangement  100 . The sensor arrangement  100  can be arranged in the upper half (in the direction of gravitation) of the safety strip  200 . Preferably, the sensor arrangement  100  is arranged in the upper third, or in the upper fourth, of the safety strip  200 . The sensor arrangement  100  is enclosed, or covered, by the safety strip  200  at least partly, in particular completely. The sensor arrangement  100  can be a radar sensor arrangement. 
     In  FIG.  1   a   , the door  300  is closed, so that the safety strip  200  touches the frame  500 . When the door  300  is closed, the sensor arrangement  100  can be set up to not take a measurement. 
       FIG.  1   b    shows the door arrangement  1000  from  FIG.  1   a   , the door  300  being partly open. When the door  300  is open, the sensor arrangement  100  can be set up to take a measurement. To do this, the sensor arrangement  100  can emit electromagnetic radiation into a monitored area and receive electromagnetic radiation from the monitored area. 
     The monitored area preferably is an entrance and/or exit area of the door  300 . The monitored area can extend perpendicular to a plane defined by the door (in a direction and/or in the opposite direction) over a distance of at least 0.1 m, or up to at least 3.0 m. This allows the monitoring of the monitored area for objects, e.g., persons or things. 
     It is intended to arrange the sensor arrangement  100  within the safety strip  200  for the most part, or even entirely. This protects the sensor arrangement  100  against vandalism, dust, and other environmental influences. 
     In  FIG.  1   b   , an object  800  is located within the monitored area. The sensor arrangement  100  emits electromagnetic radiation into the monitored area (also called monitored space). The electromagnetic radiation can be reflected at the object  800 . The reflected electromagnetic radiation can be received by the sensor arrangement  100 . The object  800  can be identified based on the electromagnetic radiation received. Moreover, it can be identified or determined, based on the electromagnetic radiation received, how far the object  800  is away from the sensor arrangement  100 . Likewise, it can be identified or determined, based on the electromagnetic radiation received, what speed the object  800  has (relative to the sensor arrangement  100 ). Likewise, it can be identified or determined, based on the electromagnetic radiation received, in which direction the object  800  is moving (relative to the sensor arrangement  100 ). It can be determined from at least one, or multiple, of these variables whether the object  800  (probably) will be caught in during a closing operation of the door  300 . At least, a risk, or a probability, of the object  800  being caught in can be determined on the basis of one or several of the variables. 
     If getting caught is determined, or if a limit value of the probability of getting caught is exceeded, the closing operation of the door  300  can be interrupted or aborted. The sensor arrangement  100  can generate a signal. The signal can be transmitted to the control system of the door  300 . Induced by the signal, the control system of the door  300  can change the control of the door  300 , e.g., as mentioned, interrupt or abort the closing operation of the door. 
     A characteristic and/or a state of the door  300  can be included to identify or determine whether during the closing operation of the door  300  the object (probably) will be caught between the door  300  and the frame  500 . Likewise, the characteristic and/or the state of the door  300  can be included to identify or determine whether a signal for changing the control of the door is generated. 
     For example, one characteristic of the door  300  is a closing speed, or a closing force, of the door. If the closing speed is high, a getting caught of the object can be predicted or determined also at a greater determined distance than if the closing speed is low. If the closing force is high, the consequence of getting caught (e.g., a risk of injury of a person) can be severe, so that the sensor arrangement  100  generates a signal for the control of the door  300  already in case of a lower risk of getting caught, or a lower probability of getting caught. 
     A state of the door  300  is, e.g., the degree of opening of the door  300 . At identical distance and movement of an object  800  relative to the sensor arrangement  100 , a getting caught, or a higher probability of getting caught, can be determined at a smaller degree of opening of the door  300  than at a larger degree of opening of the door  300 . 
       FIG.  2   a    shows a door arrangement  1000 . The door arrangement  1000  is similar to the door arrangement in  FIGS.  1   a  and  1   b   , the door arrangement  1000  in  FIG.  2   a    comprising two doors  300 ,  301 . Each of the doors  300 ,  301  can be any door disclosed herein. 
     The doors  300 ,  301  can be doors of a means of transport, e.g., of a train or a bus. The doors  300 ,  301  are a two-wing design. The doors  300 ,  301  can be sliding doors. 
     The first door  300  comprises a safety strip  200 . A sensor arrangement  100  is arranged in the safety strip  200 , as described with respect to  FIGS.  1   a  and  1   b   . The first door  300  can have a glass or a windowpane  400 . 
     The second door  301  comprises a safety strip  201 . A sensor arrangement  101  is arranged in the safety strip  201 . The second door  301  can have a glass or a windowpane  401 . Any of the doors disclosed herein can be the second door  301 . 
     In  FIG.  2   a   , the doors  300 ,  301  are closed. In the closed state, the safety strips  200 ,  201  of the first and the second door  300 ,  301  touch each other. Both safety strips can be (slightly) compressed due to that touching. 
       FIG.  2   b    shows the door arrangement  1000  in a state with open doors. The sensor arrangement  100  of the first door  300  and/or the sensor arrangement  101  of the second door  301  emit electromagnetic radiation into the monitored area. An object  800  can be located in the monitored area. The electromagnetic radiation can be reflected by the object  800 . The radiation reflected by the object  800  can be received by the sensor arrangement  100  of the first door  300  and/or by the sensor arrangement  101  of the second door  301 . Due to the electromagnetic radiation, the object can be detected, preferably as described in  FIGS.  1   a  and  1   b   . In particular, the sensor arrangement  100  of the first door  300  and/or the sensor arrangement  101  of the second door  301  can determine or identify a position or a location, a distance between the respective sensor arrangement and the object, a speed of the object (relative to the respective sensor arrangement) and/or a direction of movement of the object (relative to the respective sensor arrangement). 
     Each of the sensor arrangements  100 ,  101  can generate a signal for a control of the respective door  300 ,  301 . A movement of the respective door  300 ,  301  can be changed based on the signal or the signals. Likewise, a movement of the first and the second door  300 ,  301  can be changed based on the signal transmitted by only one of the sensor arrangements  100 ,  101 . 
       FIG.  3   a    shows a schematic section through the safety strip  200 . Moreover,  FIG.  3   a    shows a schematic section through a section of the door  300 . 
     The door  300  can comprise a fastening receiver  310 . The safety strip  200  can be inserted into the fastening receiver  310  to connect the safety strip  200  to the door  300 . The connection can be non-positive and/or positive. The connection can be detachable. The door  300  can have a first leg  320 , and a second leg  330  at a front side. Also, the door  300  can have a first projection  340 , and a second projection  350 , preferably at the front side of the door  300 . The fastening receiver  310  can be formed between the first leg  320  and the second leg  330 . The first projection  340 , and the second projection  350  can effect positive locking with the safety strip  200 , in particular in the direction of the front side to which the safety strip  200  is fastened. 
     The safety strip  200  can have a fastening section  240 . The fastening section  240  can be shaped complementary to the fastening receiver  310 . The fastening section  240  can be insertable or pushable into the fastening receiver  310  to connect the safety strip  200  to the door  300 . The fastening section  240  can have a dovetailed design. The connection between the safety strip  200  and the door  300  can be a dovetail connection. The safety strip  200  can be connected to the door  300  across its entire length. 
     The safety strip  200  can have a first receiving space  210 . The first receiving space  210  can extend across the entire length of the safety strip  200 . Alternatively, the first receiving space  210  can extend across the length of the safety strip  200  only in sections. In particular, the first receiving space  210  is open at two sides, or at not more than one side, with the opening, or openings, preferably being located at axial ends (in longitudinal direction). Perpendicular to the longitudinal extension of the safety strip  200 , the first receiving space  210  can be without openings, i.e., have no opening, or be completely enclosed by the safety strip  200 , or by the material of the safety strip  200 . 
     The safety strip  200  can have a second receiving space  220 . The second receiving space  220  can extend across the entire length of the safety strip  200 . Alternatively, the second receiving space  220  can extend across the length of the safety strip  200  only in sections. In particular, the second receiving space  220  is open at two sides, or at not more than one side, with the opening, or openings, preferably being located at axial ends (in longitudinal direction). Perpendicular to the longitudinal extension of the safety strip  200 , the second receiving space  220  can be without openings, i.e., have no opening, or be completely enclosed by the safety strip  200 , or by the material of the safety strip  200 . 
     The safety strip  200  can have a third receiving space  250 . The third receiving space  250  can extend across the entire length of the safety strip  200 . Alternatively, the third receiving space  250  can extend across the length of the safety strip  200  only in sections. In particular, the third receiving space  250  is open at two sides, or at not more than one side, with the opening, or openings, preferably being located at axial ends (in longitudinal direction). Perpendicular to the longitudinal extension of the safety strip  200 , the third receiving space  250  can have at least one opening, preferably at least two or three openings. 
     The safety strip  200  can have a hollow space  230 . The hollow space  230  can extend across the entire length of the safety strip  200 . Alternatively, the hollow space  230  can extend across the length of the safety strip  200  only in sections. In particular, the hollow space  230  is open at two sides, or at not more than one side, with the opening, or openings, preferably being located at axial ends (in longitudinal direction). Perpendicular to the longitudinal extension of the safety strip  200 , the hollow space  230  can have at least one opening, preferably at least two or three openings. Perpendicular to the longitudinal extension of the safety strip  200 , the hollow space  230  can have at least one opening, preferably at least two or three openings. Perpendicular to the longitudinal extension of the safety strip  200 , the hollow space  230  can be without openings, i.e., have no opening, or be completely enclosed by the safety strip  200 , or by the material of the safety strip  200 . Likewise, the hollow space  230  can be completely closed, i.e., have no opening, or be completely enclosed by the safety strip  200 , or by the material of the safety strip  200 . 
       FIG.  3   b    shows the safety strip  200  in a state in which it is connected to the door  300 . The fastening section  240  of the safety strip  200  can be arranged in the fastening receiver  310  of the door  300 . 
     The sensor arrangement  100  is arranged in the first receiving space  210 . Due to the design of the first receiving space  210 , electromagnetic radiation passes through the safety strip  200 , or through the material of the safety strip  200 , when the sensor arrangement  100  emits electromagnetic radiation into the monitored area. The receiving space  210  is arranged in particular between a fastening area of the safety strip  200 , and a contact area of the safety strip  200 . In this way, reliable reception of the sensor arrangement  100  can be ensured, and the other functions of the safety strip  200  can still be guaranteed. Also, electromagnetic radiation from the monitored area can pass through the safety strip  200 , or through the material of the safety strip  200 , when the sensor arrangement  100  receives electromagnetic radiation. Preferably, the first receiving space  210  is designed within the safety strip  200  in such a way that electromagnetic radiation from the sensor arrangement  100  into the monitored area and/or from the monitored area to the sensor arrangement  100  only (i.e., exclusively) passes through the material of the safety strip  200 , or through the safety strip  200 . If additional elements are arranged along the path of the electromagnetic radiation between the sensor arrangement  100  and the monitored area, part of the electromagnetic radiation might be absorbed and/or reflected, which might falsify the measurement. 
     A contact strip  270  can be arranged within the second receiving space  220 . In the direction of a front side of the door  300 , or the contact area of the safety strip  200 , in particular the front side of the door  300  where the safety strip  200  is arranged or connected, the hollow space  230  can be arranged in front of the second receiving space  220 . The hollow space  230  in front of the second receiving space  220  in which the contact strip  270  is arranged facilitates a deformation of the safety strip  200 , or of the material of the safety strip  200 . Due to this, the contract strip  270  can trigger at a lower force than without the hollow space  230 . When the contract strip  270  triggers, at least one section of the safety strip  200  is compressed in such a way that an object has been, or is probable to have been, caught in. When it triggers, the contact strip  270  can send a signal to the control system of the door  300  based on which the movement of the door  300  is changed, e.g., a closing operation is interrupted or aborted. 
     A light curtain arrangement  280  can be arranged within the third receiving space  250 . The light curtain arrangement  280  can be arranged within the third receiving space  250  in such a way that the light curtain arrangement  280  emits light into the monitored area, preferably in a wavelength range not visible to humans. A receiver for the light can be provided at a frame, or a door, located opposite the light curtain arrangement  280 . The light curtain arrangement  280  can trigger when reception of the light is interrupted, e.g., by an object within the monitored area. When the light curtain arrangement  280  triggers, a signal can be sent to the control system of the door  300 , based on which the movement of the door  300  is changed, e.g., a closing operation is interrupted or aborted. 
     The contact strip  270 , the light curtain arrangement  280 , the second receiving space  220 , the third receiving space  250  and/or the hollow space  230  are optional. 
       FIG.  4    shows a schematic diagram of a sensor arrangement  100 . The sensor arrangement  100  can comprise a receiving arrangement  110 . The receiving arrangement  110  can comprise at least one antenna, preferably at least two antennae, more preferably at least three antennae, more preferably at least four antennae. Each of the antennae R 1 , R 2 , R 3 , R 4  can receive electromagnetic radiation from the monitored area. 
     In the receiving arrangement  110 , the distance between any two of the antennae R 1 , R 2 , R 3 , R 4  can be a distance sR 1  of between 0.1 to 0.9, or, especially preferred, of approximately half the wavelength of the electromagnetic radiation (approximately 0.5 times the wavelength of the electromagnetic radiation) in a first direction. Alternatively, or in addition, the distance between any two of the antennae R 1 , R 2 , R 3 , R 4  can be a distance sR 2  of between 0.1 to 0.9, or, especially preferred, of approximately half the wavelength of the electromagnetic radiation (approximately 0.5 times the wavelength of the electromagnetic radiation) in a second direction. The first direction can be not in parallel with, in particular perpendicular to, the second direction. 
     The sensor arrangement  100  can comprise a transmitting arrangement  120 . The transmitting arrangement  120  can comprise at least one antenna, preferably at least two antennae, more preferably at least three antennae. Each of the antennae T 1 , T 2 , T 3  can emit electromagnetic radiation into the monitored area. 
     In the transmitting arrangement  120 , the distance between any two of the antennae T 1 , T 2 , T 3  can be a distance sT 1  of between 0.6 to 1.5, or, especially preferred, of approximately one times the wavelength of the electromagnetic radiation (approximately 1.0 times the wavelength of the electromagnetic radiation) in a first direction. Alternatively, or in addition, the distance between any two of the antennae T 1 , T 2 , T 3  can be a distance sT 2  of between 0.6 to 1.5, or, especially preferred, of approximately one times the wavelength of the electromagnetic radiation (approximately 1.0 times the wavelength of the electromagnetic radiation) in a second direction. The first direction can be not in parallel with, in particular perpendicular to, the second direction. 
     The sensor arrangement  100  can comprise a controller  130 . The controller  130  can be set up to control the sensor arrangement  100 . In particular, the controller  130  is set up to control the transmitting arrangement  120 . The emission of electromagnetic radiation into the monitored area can be controllable by the controller  130 . In particular, the controller can receive signals from a further control system, which signal that an opening or closing operation of the one, or multiple, doors shall start, and that activation of the sensor arrangement  100  is necessary. The controller  130  can be set up to edit and/or evaluate signals from the receiving arrangement  110 . Alternatively, the controller  130  can be located outside of the sensor arrangement  100 . 
     The sensor arrangement  100  can comprise a power supply system  140 . The power supply system  140  can supply energy, in particular electric energy, to the sensor arrangement  100 . The power supply system  140  can comprise a battery or a rechargeable battery. The power supply system  140  can be set up to receive electric power wirelessly, e.g., by means of induction. Alternatively, or in addition, the power supply system  140  can be connected to a power supply outside of the safety strip  200 . The connection can be a hardware-based connection, e.g., wiring. 
     The sensor arrangement  100  can comprise a data interface  150 . The data interface  150  can be set up to transmit data to outside of the safety strip  200  wirelessly or by wire. Alternatively, or in addition, the data interface  150  can be set up to receive data from outside of the safety strip  200  wirelessly or by wire. In particular, the data interfaces  150  is connected to a control system of the door. 
     The sensor arrangement  100  can comprise a memory  160 . The memory  160  can comprise a volatile memory and/or a non-volatile memory. Data from the receiving arrangement  110  can be stored in the memory  160 . An algorithm, or multiple algorithms, for evaluating data in the memory  160 , in particular data from the receiving arrangement  110 , can be stored in the memory  160 . 
       FIG.  5   a  to  5   d    show measurements by the sensor arrangement  100  of a door arrangement  1000 . In  FIG.  5   a   , at least one door is open, in particular both doors. The sensor arrangement  100  emits electromagnetic radiation into the monitored area and receives electromagnetic radiation from the receiving area. No object (to be detected) is located within the monitored area. 
     The measurement is visualized in  FIG.  5   b  to  5   c   .  FIG.  5   b    shows a diagram on the basis of the electromagnetic radiation received. An angle in degrees (°) is plotted against a distance in meters (m). Different signal intensities in decibels (dB) are indicated by areas of different color or shading. In  FIG.  5   b   , the angle is an azimuth angle. 
       FIG.  5   b    shows several areas of relatively high signal intensity. These areas are caused by reflections of the electromagnetic radiation emitted by the sensor arrangement  100 . For example, an area  810  of high signal intensity is formed at a distance of approximately 1.6 m over an azimuth angle range of approximately −20° to more than 80°. This area can be caused by a reflection of the electromagnetic radiation at the floor of the door, e.g., at the floor of a bus or a train. Furthermore, an area  820  of high signal intensity is formed at a distance of approximately 0.7 m over an azimuth angle range of approximately −40° to approximately 30°. This area can be caused by a reflection of the electromagnetic radiation at a grab element, e.g., a grab pole, in the door area. 
       FIG.  5   c    shows a diagram similar to that in  FIG.  5   b   , the angle in  FIG.  5   c    being an elevation angle.  FIG.  5   c    again shows several areas of higher signal intensity. For example, an area  811  of high signal intensity is formed at a distance of approximately 1.6 m and an elevation angle range of approximately 0° to more than 80°. Again, this area can be caused by a reflection of the electromagnetic radiation at the floor of the door. 
       FIG.  5   d    shows a diagram similar to that in  FIGS.  5   b  and  5   c   , with the speed in meters per second (m/s) being plotted against the distance in meters (m). The diagram is marked “Doppler”, because the speed measurement is based on the Doppler effect. Only low speeds (negative and positive speeds) are visible in the scenario of  FIG.  5     a.    
     The signals, as shown in  FIG.  5   b  to  5   d   , can be regarded as background. If no object  800  to be detected is located within the monitored area, i.e., if the monitored area is free from objects  800  to be detected, a measurement by the sensor arrangement  100  results as shown in  FIG.  5   b  to  5   d   . The background can be deducted in a further measurement, or be taken into account in a further measurement, to improve the detection of objects to be detected. The background can be an object to be detected. 
       FIG.  6   a  to  6   d    show a measurement by the sensor arrangement  100  where an object  800  to be detected is located within the monitored area. The object  800  is moving away from the sensor arrangement  100 . In the diagram in  FIG.  6   b   , an area  800   b  with a higher signal intensity is visible, which is in addition to the diagram in  FIG.  5   b   . The area  800   b  is formed at a distance of approximately 0.6 m and an azimuth angle range of approximately −25° to approximately 0°. This area  800   b  is caused by a reflection of the electromagnetic radiation at the object  800  to be detected. 
     Analogously, an area  800   b  is visible in the diagram in  FIG.  6   c   , which is in addition to the diagram in  FIG.  5   c   . This area is formed at a distance of approximately 0.6 m and an elevation angle of approximately 0° to approximately 60°. Again, the area  800   c  is caused by a reflection of the electromagnetic radiation at the object  800  to be detected. 
     In  FIG.  6   d   , an area  800   d  of increased signal intensity is formed at a distance of approximately 0.6 m and a speed of approximately 0.5 m/s, which is due to the reflection of the electromagnetic radiation at the object  800  to be detected. The positive speed indicates that the object  800  is moving away from the sensor arrangement  100 . 
       FIG.  7   a  to  7   d    show a measurement by the sensor arrangement  100  where an object  800  to be detected is located within the monitored area. The object  800  is moving in the direction of the sensor arrangement  100 , i.e., the object  800  is moving towards the sensor arrangement  100 . 
     An area  800   b  at a distance of approximately 0.4 m and an azimuth angle range of approximately −60° to approximately 20° is visible in  FIG.  7   b   , an area  800   c  at a distance of approximately 0.4 m and an elevation angle range of approximately 0° to more than 80° is visible in  FIG.  7   c   , and an area  800   d  at a distance of approximately 0.4 m and a speed of approximately −0.5 m/s is visible in  FIG.  7   d   . The areas  800   b ,  800   c , and  800   d  are caused by the object to be detected. The negative speed indicates that the object  800  to be detected is moving in the direction of the sensor arrangement  100 , i.e., is moving towards the sensor arrangement  100 . 
     The location of an object  800 , a distance of the object  800  to the sensor arrangement  100 , a speed of the object  800  relative to the sensor arrangement  100  and/or a direction of movement of the object relative to the sensor arrangement  100  can be determined from the measurement by the sensor arrangement  100 . Due to this, a monitored area can be monitored especially well. 
     In principle, the measurement can be performed with the following steps. The controller can be set up to carry out the following steps. One or several of the steps can be optional. 
     The sensor arrangement can emit electromagnetic radiation, preferably within a wide solid angle range, by means of at least one antenna (transmitting antenna). The solid angle range can be at least 30°, at least 45°, at least 60°, at least 75°, or at least 90°. 
     Reflected electromagnetic radiation can be received by the sensor arrangement by at least two antennae (receiving antennae). Each of the antennae can be a transmitting antenna and/or a receiving antenna. 
     A signal preparation can be applied to the electromagnetic radiation received, in particular to a signal that is based on the electromagnetic radiation received. The signal preparation can comprise one or multiple filters. The signal can comprise the totality of all variables, e.g., for different receiving antennae. 
     The signal received can be resolved into intermediate information. Intermediate information can be, e.g., distances, angles, speeds and/or signal intensities and/or other, possibly abstracted, variables. The variables can enable subsequent classification of objects, e.g., as regards their type, state and/or relevance and/or additional classes. Examples of variables include “type”, “state” and/or “relevance” and/or the additional classes. The classes can be subdivided into at least two subclasses. For example, “type” can be subdivided into, e.g., [“person”, “door” ], or “state” can be subdivided into, e.g., [“moves towards door”, “moves away from door”, “does not move” ], or “relevance” can be subdivided into, e.g., [“relevant”, “not relevant” ]. 
     The application scenario and/or the classification of objects in the scenario can be analyzed, e.g., on the basis of the direct and/or abstracted intermediate information from the step described previously. The scenario can subsequently be interpreted. A signal describing the scenario can be triggered, e.g., by the controller. For example, when monitoring a closing door and an approaching person, the signal can be a signal that can be used to abort the closing operation of the door. The scenario can be interpreted algorithmically. To interpret the scenario, an algorithm can be used that learns from data. In particular, machine learning, e.g., supervised machine learning, unsupervised machine learning, reinforcement learning, can be used for learning. 
       FIG.  8   a    shows a door  300  with a safety strip  200 . A sensor arrangement  100  is arranged in the safety strip  200 .  FIG.  8   a    shows a schematic top view of the door  300 . The top view shows the door in a plane perpendicular to the direction of gravitation, or in parallel with a floor. 
     When the sensor arrangement  100  emits electromagnetic radiation, a monitored area  900  results. The sensor arrangement  100  can be designed in such a way that the electromagnetic radiation is emitted in a wide solid angle, or solid angle range. In this way, an entrance and/or exit area can be monitored especially well, because the monitored area is relatively large. The solid angle, or solid angle range, can be at least 30°, at least 45°, at least 60°, at least 75°, or at least 90°. The solid angle, or solid angle range, can extend perpendicular to the direction of gravitation, or in parallel with the floor. 
       FIG.  8   b    shows a two-wing door arrangement. A side view of the door arrangement is shown. The side view can be oriented perpendicular to the floor, or in parallel with the direction of gravitation. 
     A first door  300  comprises a safety strip  200 . The safety strip  200  of the first door  300  comprises a sensor arrangement  100 . A second door  301  comprises a safety strip  201 . The safety strip  201  of the second door  301  comprises a sensor arrangement  101 . 
     The sensor arrangement  100  of the first door  300  and the sensor arrangement of the second door  301  can emit electromagnetic radiation into the respective monitored area  900 ,  901 . Each of the sensor arrangements  100 ,  101  can emit electromagnetic radiation into the monitored area in a wide solid angle, or solid angle range. The solid angle, or solid angle range, can be at least 30°, at least 45°, at least 60°, or at least 75°. The solid angle, or solid angle range, can extend in the direction of gravitation, or perpendicular to the floor. 
     At least one of the monitored areas  900 ,  901 , or each of the monitored areas  900 ,  901 , can extend over a height of at least 30%, preferably at least 50%, more preferably at least 70%, more preferably at least 80% of the total height or total length of the respective safety strip  200 ,  201 . 
     A monitored area  900 ,  901  can extend from the safety strip  200 ,  201 , in which the associated sensor arrangement  100 ,  101  is arranged, up to an opposite frame or an opposite door.