Access control system for buildings

Abstract

Access control system (1) for buildings (2) with a stationary unit (20) and a mobile unit (10), wherein the mobile unit (10) has a mobile transceiver (11) which is designed to wirelessly and encryptedly transmit signals (S) for authentication and authorization of the mobile unit (10) with respect to the stationary unit (20) and for control of the stationary unit (20) by the mobile unit (10) to a stationary transceiver (21) of the stationary unit (20), which has at least a first antenna array (23A) and a second antenna array (23B), wherein the antennas (23) of the respective antenna array (23A, 23B) lie in a common antenna reference plane (E1, E2) and the antenna reference planes (E1, E2) of the antenna arrays (23A, 23B) are tilted relative to one another, wherein the stationary unit (20) comprises a control device (22) which is designed to determine a distance (r) and an angle (Φ) as a position of the mobile unit (10) relative to the stationary unit (20) from signals (S) transmitted from the mobile transceiver (11) to the stationary transceiver (21), so that the position of the mobile unit (10) can be specified as polar coordinates of a polar coordinate system lying in a horizontal plane, in whose coordinate origin the stationary transceiver (21) is arranged, and to control a function when a control command for triggering the function is transmitted to the stationary unit (20) by a mobile unit (10) authenticated and authorized by the stationary unit (20) and / or the position of the mobile unit (10) is within a predetermined access area (30), and wherein the control device (22) is designed to determine a respective reception angle (Φ1, Φ2) specific for the respective antenna array (23A, 23B) from signals (S) transmitted from the mobile transceiver (11) to the stationary transceiver (21) and received by the antenna arrays (23A, 23B), to determine a quadrant of the polar coordinate system in which the position lies from the reception angles (Φ1, Φ2), and to determine the angle (Φ) of the position from the reception angle (Φ1, Φ2), which lies in an angular range predetermined for the respective antenna array (23A, 23B) with a predetermined low measurement error, and the quadrant.

Description

[0001] The invention relates to an access control system for buildings.

[0002] An access control system within the meaning of the invention is understood to mean systems that have a stationary or fixed unit and a mobile unit that can be carried by a user, and in which said units communicate wirelessly with each other for the authentication and authorization of the mobile unit, and thus of the user, vis-à-vis the stationary unit. Based on the authentication and authorization, the stationary unit controls various functions and, in particular, the release or locking of an associated access, for example, a door or gate. Going beyond most conventional access systems, the access system according to the invention also provides for position determination, as explained in more detail below.

[0003] Wireless access control systems are state of the art and are known, for example, from the documents WO 2023 / 222462 A1 and DE 10 2020 114 403 A1.

[0004] However, such systems can be further optimized.

[0005] The invention is therefore based on the object of overcoming the aforementioned disadvantages and providing an access control system with improved security and increased convenience.

[0006] This problem is solved by the combination of features according to claim 1.

[0007] According to the invention, an access control system for buildings or a building access control system is therefore proposed, which accordingly has a stationary unit, i.e. a fixed unit and preferably a fixed unit connected to the building, and a mobile unit, i.e. a non-stationary unit and in particular a unit that can be carried by a user. The mobile unit is essentially an electronic key, which can be designed, for example, in the form of a smart FOB or a smartphone. Basically, both the stationary unit and the mobile unit have a respective transceiver, wherein a transceiver is to be understood as a transmitting / receiving unit. The transceiver of the mobile unit, referred to as the mobile transceiver, preferably has at least one antenna and an evaluation unit for transmitting signals via the at least one antenna and for evaluating the signals received via the at least one antenna.The transceiver of the stationary unit, referred to as the stationary transceiver, preferably has at least two antennas and an evaluation unit for transmitting signals via at least one of the two antennas and for evaluating the signals received via both antennas. The mobile transceiver is designed to transmit wirelessly, in particular via radio, and encrypted signals for authentication and authorization of the mobile unit to the stationary unit, as well as optionally for control of the stationary unit by the mobile unit, to the transceiver of the stationary unit, referred to as the stationary transceiver.

[0008] Fundamentally, it should be noted that authentication is understood as the verification of whether the mobile unit or its identity is known to the stationary unit, in particular, whether a unique identification number of the mobile unit is stored in the stationary unit. Authorization, on the other hand, is understood as the verification of whether the authenticated mobile unit has access authorization for the access controlled by the access control system. Authentication and authorization can be performed integrally or separately.

[0009] Essential to the invention is that the stationary transceiver has multiple antenna arrays, and thus at least a first antenna array and a second antenna array, wherein the antennas of the respective antenna arrays lie in a common antenna reference plane of the respective antenna array. The antenna reference planes of the antenna arrays are, in turn, tilted relative to one another and thus not parallel. In a particularly preferred embodiment, in which exactly two antenna arrays are provided, the correspondingly exactly two antenna reference planes run perpendicular or orthogonal to one another.Furthermore, it is essential to the invention that the stationary unit has a control device which is designed to determine a distance and an angle as a position of the mobile unit relative to the stationary unit from the signals transmitted from the mobile transceiver to the stationary transceiver, so that the position of the mobile unit can be specified as polar coordinates of a polar coordinate system lying in a horizontal plane, in whose coordinate origin the stationary transceiver is arranged. Based on this, the control device is further designed to trigger or execute a function corresponding in particular to a corresponding control command.to control if a control command for triggering the function is transmitted to the stationary unit by a mobile unit authenticated and authorized by the stationary unit and / or the position of the mobile unit is within a predetermined access area which can be learned in particular by a user or an authenticated and further preferably authorized user, which can be determined, for example, solely by a distance of the mobile unit from the stationary unit or the position of the mobile unit, so that the mobile unit can be considered to be within the access area if the distance mentioned below is less than a predetermined limit value.

[0010] The access area is understood to be a two-dimensional and horizontally extending area on or around the stationary unit and, accordingly, for example and in abstract terms, an area on a floor in the area of the stationary unit or of an access controllable by the access control system, as could be represented, for example, in a view from above or a plan view.

[0011] Accordingly, the polar coordinate system preferably lies in a horizontal plane relative to the earth or the ground.

[0012] Furthermore, it is preferably provided that polar coordinates to the right of the stationary transceiver are located in the positive angular direction of the polar coordinate system, and polar coordinates to the left of the stationary transceiver are located in the negative angular direction of the polar coordinate system. Left and right are to be understood as pointing away from a top view and from the perspective of the stationary transceiver, as well as from the building.

[0013] Accordingly, it is advantageous for comfort and safety if the position of the user or the mobile unit can be determined as accurately as possible.

[0014] However, if a position angle is determined from a signal received via only one antenna array or via exactly two antennas, the problem is that the angle determination, especially when determined using the phase shift between a signal received at two antennas, is subject to tolerance or error, and the measurement error depends on the angle. Relative to the antenna reference plane, the tolerance or error increases the greater the phase shift or the less perpendicular the signal is to the antenna reference plane. Therefore, if the angle relative to a reference line perpendicular to the antenna reference plane or orthogonal to the antenna plane increases, the error also increases.At an angle of 0° between a reception angle of the signal and the reference line, i.e. when they are parallel, the error is correspondingly minimal, and at an angle of +90° or -90° to the reference line the error is maximum.

[0015] However, the measurement error does not increase linearly between its minimum and maximum. Therefore, there is a preferred range around the reference line or the 0° angle, in which the measurement error remains comparatively low.

[0016] Preferably, the reference lines of the antenna reference planes pass through the coordinate origin of the common polar coordinate system, since otherwise a transformation between the different values would have to be provided.

[0017] Irrespective of this, it is also not possible to reliably determine in which quadrant of the polar coordinate system the position of the mobile unit lies from the signal received by only one antenna array, since the reception angle applies to two possible positions.

[0018] It is therefore essential to the invention that the control device is designed to determine a respective reception angle specific to the respective antenna array, i.e. at least a first reception angle specific to the first antenna array and a second reception angle specific to the second antenna array, from signals transmitted from the mobile transceiver to the stationary transceiver and received by the antenna arrays. The control device then uses the reception angles to determine a quadrant of the polar coordinate system in which the position lies. The position of the mobile unit can then be determined by the control device from the quadrant of the polar coordinate system in which the position of the mobile unit lies and the reception angle, which lies in an angular range predetermined for the respective antenna array, which corresponds to the aforementioned predetermined range with low measurement error.The position of the mobile unit is indicated accordingly with the angle which is subject to a smaller measurement error.

[0019] The access area is understood to be a two-dimensional and horizontally extending area on or around the stationary unit and, accordingly, for example and in abstract terms, an area on a floor in the area of the stationary unit or of an access controllable by the access control system, as could be represented, for example, in a view from above or a plan view.

[0020] The functions that can be controlled by corresponding control commands include, in particular, comfort functions, so that lighting elements, for example, can also be controlled by a corresponding control command.

[0021] However, basic functions of the access control system, and thus in particular unlocking and locking an access controlled by the access control system, preferably do not require the transmission of a control command, but are performed automatically by the control device when an authenticated and authorized mobile unit, i.e., its position, is within the access area. Repeated position determination also makes it possible to distinguish between entering and leaving the access area, and to trigger a corresponding function, e.g., unlocking the access upon entering and locking the access upon leaving.

[0022] The transceivers are preferably combined Bluetooth or Bluetooth Low Energy, BLE for short, and ultra-wideband transceivers, UWB transceivers for short, although other radio methods or radio transceivers can also be used, provided they enable the position to be determined according to the invention.

[0023] It is generally known that position determination is possible using such transceivers, but this will be explained in more detail below.

[0024] According to an advantageous development, the first antenna array has two, in particular exactly two, antennas, and all antennas of the first antenna array extend in a common first antenna reference plane or define this common first antenna reference plane. Similarly, the second antenna array also has two, in particular exactly two, antennas, wherein all antennas of the second antenna array also extend in a common second antenna reference plane or define this common second antenna reference plane.

[0025] Preferably, exactly two antenna arrays are provided, the antenna reference planes of which extend orthogonally to one another or are perpendicular to one another. Thus, the antenna reference planes enclose an angle of 90° between them. Based on the respectively determined reception angle, the control device is configured to determine, exclusively from the reception angle, the angle of the polar coordinates that lies within the preferred, i.e., predetermined, angular range, which, for the two mutually orthogonal antenna reference planes, is ±45° around a reference line extending perpendicularly through the respective antenna reference plane.

[0026] Preferably, it is further provided that the control device is designed to determine the position as lying in the quadrant of the polar coordinate system if both a first reception angle specific to the first antenna array and a second reception angle specific to the second antenna array lie in the quadrant.

[0027] Furthermore, the control device can be designed to determine, from signals transmitted from the mobile transceiver to the stationary transceiver and received by the antenna arrays, a respective reception distance specific to the respective antenna array from which the signal was received, and to determine the distance of the position from the reception distances.

[0028] Furthermore, it is preferably provided that the control device is designed to determine a distance from which the signal was received from the signal transmitted at least partially by means of the first antenna array from the mobile transceiver to the stationary transceiver, and / or to determine the distance or a distance from which the signal was received from the signal transmitted at least partially by means of the second antenna array from the mobile transceiver to the stationary transceiver.

[0029] In principle, determining a distance is sufficient, so that it can be directly specified as the actual distance from the actual position. However, it is advantageous to calculate and / or verify an average of all determined distances in order to be able to specify the actual distance with greater certainty and accuracy.

[0030] If at least one of the coordinate origins of the antenna array-specific polar coordinate systems deviates from the coordinate origin of the common polar coordinate system in whose coordinate origin the stationary unit is arranged, it can also be provided that, in order to determine the angle of the polar coordinates for the position of the mobile unit and / or to determine the distance of the polar coordinates for the position of the mobile unit, a transformation takes place from the respective antenna array-specific polar coordinate system to the polar coordinate system in whose coordinate origin the stationary unit is arranged. The relative positioning of the antennas of the antenna arrays to one another and to the coordinate origin of the common polar coordinate system is preferably known for this purpose and stored in the control device for carrying out the transformation.

[0031] In principle, it is sufficient to determine the distance only once. However, the distance can optionally be determined once per antenna array to also check the distance or to calculate an average value as the distance of the polar coordinates to increase accuracy and reliability.

[0032] However, the measured distance corresponds to the length of the direct connection between the stationary and the mobile transceiver, so that a deviation may occur in the polar coordinate system extending in the horizontal plane due to a possible difference in height between the mobile transceiver and the stationary transceiver in three-dimensional space.

[0033] In particular, it is provided that the two antennas of a respective antenna array each have a respective predetermined distance from each other in the horizontal plane. This allows the control device to determine the respective reception angles from a phase shift between the signal received at least partially at the two antennas of the respective antenna array and the distance.

[0034] The phase shift can be determined using the so-called Phase Difference of Arrival (PDoA).

[0035] The angle is preferably determined using the formula Φ=arcsin(α∗λ2∗π∗d) with Φ is the angle from which the signal from the mobile transceiver was received by the stationary transceiver, α phase shift between the signal received at both antennas, λ as a wavelength of a carrier frequency of the signal and d is the distance between the two antennas in the horizontal plane.

[0036] However, if the measurement error or the associated tolerance is taken into account, the angle Φ=arcsin((α±Δα)∗λ2∗π∗d) with Δα Tolerance / measurement error of the measured phase shift α.

[0037] With regard to the phase shift, it should be clarified that a signal is received by the two antennas spaced apart from each other with waves or phases shifted from each other due to the distance, whereby the phase shift corresponds to the shift of the phases or carrier waves from each other.

[0038] With regard to the wavelength of the carrier frequency of the signal, this can be determined by the control device from the signal, but can preferably already be stored in the control device or can be retrieved by it.

[0039] Likewise, the distance between the two antennas in the horizontal plane should preferably already be stored in the control device or be retrievable by it.

[0040] However, the calculation applies to two angles, so that one of the angles is the actual angle of the actual position of the mobile unit and the other is merely a virtual or mirrored angle, which leads to the virtual or mirrored and thus not actual or incorrect position of the mobile unit.

[0041] The access control system designed according to the invention can exclude incorrect or mirrored angles and positions and thus clearly determine the actual angle and position.

[0042] When determining angles and distances, different values for distance and angle can be determined by varying the alignment and offset of the antenna arrays. These values are each related to an array coordinate system determined by the alignment and positioning of the antenna arrays. These values can be transformed into the polar coordinate system by knowing the alignment and positioning of the antenna arrays relative to each other and to the polar coordinate system or its coordinate origin.

[0043] Advantageously, the antennas of each of the arrays each determine an antenna reference plane, so that it can be provided that all antennas of the respective antenna array are formed on a respective printed circuit board grounded in a common plane or preferably a common printed circuit board determining the respective antenna reference plane.

[0044] Furthermore, the access control system can have a switching device connected between the control device and the antenna arrays, which is designed to alternately switch a transceiver electronics unit of the stationary transceiver to the antenna arrays while the signal is being received, so that the antenna arrays each receive a portion of the signal, and the signal received via the antenna arrays is transmitted to the transceiver electronics unit of the stationary transceiver and from there, preferably, to the control device. This requires only one transceiver electronics unit or one stationary transceiver, as well as only one control device or evaluation electronics unit, since these can be used to evaluate all signal components, which in particular leads to significant cost savings.

[0045] Starting from a switching device, switching can also occur multiple times during signal transmission.

[0046] It should be noted that a signal does not transmit a single, complete data packet throughout, but rather consists of several signal components. The signal components, depending on the order in the signal, are "Pre-Poll," "Poll," "Final," and "Final Data."

[0047] Preferably, the switching device switches after the end of the reception of a signal part or before the reception of a signal part, so that the signal parts are received by different antenna arrays.

[0048] For example, the signal part referred to as “Pre Poll” can be received by the first antenna array, the signal part referred to as “Poll” by the second antenna array, the signal part referred to as “Final” again by the first antenna array, and the signal part referred to as “Final Data” again by the second antenna array.

[0049] From each signal part, a respective reception angle and, if applicable, a respective distance can then be determined, so that an angle and a distance can then be specified as polar coordinates of the position of the mobile unit.

[0050] Consequently, the signals detected by the antenna arrays can also be evaluated separately and by their own control devices or evaluation devices, and the respective reception angles and distances can be determined.

[0051] According to a further aspect of the invention, an access control system according to the invention, and in particular the control device for carrying out a method for determining a position of a mobile unit, is designed with an access control system according to the invention. According to the method, a respective reception angle specific to the respective antenna array is determined from signals transmitted from the mobile transceiver to the stationary transceiver and received by the antenna arrays, in which the antenna array preferably has a predetermined low measurement error. Subsequently, a quadrant of the polar coordinate system in which the position of the mobile unit lies is determined from the reception angles, and the angle of the position is determined from the reception angle, which lies in an angular range predetermined for the respective antenna array, and the quadrant in which the position lies.

[0052] What has been said regarding the access control system also applies directly to the procedure.

[0053] The features disclosed above can be combined as desired, as long as this is technically possible and they do not contradict each other.

[0054] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. They show: Fig. 1 an access control system in a plan view; Fig. 2 a segmentation of a polar coordinate system determined by distance grids and angle grids; Fig. 3 Representation of a position ambiguity with an antenna reference plane; Fig. 4 Illustration of a position ambiguity with two antenna reference planes; Fig. 5 measurement errors over the respective reception angle; Fig. 6 Representation of the predetermined areas for two antenna arrays; Fig. 7 a process for determining a position of a mobile unit.

[0055] The figures are schematic examples. Like reference numerals in the figures indicate like functional and / or structural features.

[0056] In Fig. 1, the essential components of an access control system 1 on a building 2 according to the invention are shown schematically.

[0057] Such an access control system 1 basically comprises a stationary unit 20 and a mobile unit 10, wherein the stationary unit 20 is stationary or connected to the building 2 and is designed to control the access 3, for example a door, of the building 2 and accordingly, in particular, to lock or unlock the access 3 or the door 3 depending on the position of the mobile unit 10, wherein the stationary unit 20 receives signals S from the mobile unit 10 to determine the position and to authenticate and authorize the mobile unit 10. The mobile unit 10 has a mobile BLE-UWB transceiver 11, which is designed to wirelessly and encryptedly transmit signals S for authentication and authorization of the mobile unit 10 to the stationary unit 20 and, if necessary, for control of the stationary unit 20 by the mobile unit 10 to a stationary BLE-UWB transceiver 21 of the stationary unit 20.

[0058] In general, identification and authentication preferably take place via BLE, whereas localization and positioning preferably takes place via cryptologically secured communication via UWB.

[0059] It can be provided that the control of the stationary unit 20 should not be based, or at least not exclusively, on control commands received from the mobile unit 10, but rather it should be checked whether the mobile unit is located within a predetermined access area 30.

[0060] Accordingly, the stationary unit 20 has a control device 22, which is designed to determine a position of the mobile unit 10 relative to the stationary unit 20 from the signals S transmitted from the mobile transceiver 11 to the stationary transceiver 21 and to control a function when the position of the mobile unit 10 is within a predetermined access area 30. Optionally, it may also be necessary for a mobile unit 10 authenticated and authorized by the stationary unit 20 to transmit a control command to trigger the function to the stationary unit 20.

[0061] As exemplified in the Fig. 1 and Fig. 2, the predetermined access area can be a delimited area or a delimited region within a polar coordinate system, in the center of which the stationary unit 20 is arranged. However, the predetermined access area 30 can be a predetermined angular range, distance range, a combination of angular and distance range, or the entire area of the stationary unit that can be detected by the polar coordinate system, so that in the latter case, the access area 30 would be determined solely by a maximum transmission or reception power of the two transceivers 11, 21 or the transmission or reception power of the stationary transceiver 21 operating in locating mode.

[0062] Basically, it is provided that the control device 22 determines an angle Φ from which the signals S were received from the signals S transmitted from the mobile transceiver 11 to the stationary transceiver 21, and determines a distance r from which the signals S were received, so that the respective position of the mobile unit 10 can be specified as polar coordinates of the polar coordinate system.

[0063] In order to simplify and thus accelerate calculations and comparisons, it can be provided that the polar coordinate system is divided by a distance grid 41 and an angle grid 42 or is segmented into individual segments 46, so that virtual, i.e. imaginary, nodes 43 are formed at the intersection points of the distance grid 41 with the angle grid 42, whereby each segment 46 is determined by four nodes 43, as shown in Fig. 2 is shown.

[0064] Based on this, the control device 22 can be configured to normalize the previously determined position of the mobile unit 10 to the nearest node 43.

[0065] Also with reference to Fig. 2 shows that the access area 30 can be determined, for example, by boundary points 31 normalized to the node points 43.

[0066] The determination of the angle Φ is schematic and simplified in Fig. 3, wherein only the mobile transceiver 11 and a first antenna array 23A of the stationary transceiver 21 are shown in the configuration already shown in the Fig. 1 and Fig. 2 referenced view from above.

[0067] The illustrated first antenna array 23A accordingly has exactly two antennas 23 for receiving a signal S transmitted from the mobile transceiver 11 to the stationary transceiver 21, wherein the exactly two antennas 23 have a known distance d from one another in the horizontal plane in which the polar coordinate system lies and are arranged in a common first plane E1 or first antenna reference plane E1.

[0068] The angle Φ is determined from a phase shift α between the signal S received at both antennas 23 or a phase shift α between the carrier waves 24 of the signal S received at both antennas 23 and the distance d between the antennas 23.

[0069] In particular, the angle Φ is given by the formula Φ=arcsin(α∗λ2∗π∗d) where λ is known in advance as a wavelength of the carrier frequency or the carrier wave 24 of the signal S and is stored in the control device 22 or can be retrieved by it. The distance d of the antennas 23 can also be stored in the control device 22 or can be retrieved by it.

[0070] The formula mentioned is, as in Fig. 3, but valid for two angles Φ or for two coordinates, so that in addition to the actual position P10 of the mobile unit 10 or its mobile transceiver 11, a first mirrored or virtual position P11 of an image of the mobile transceiver 11 that is not actually present and can therefore be designated as a “ghost transceiver” 12 is also determined, as is also shown in the overview according to Fig. 1 is shown.

[0071] For the stationary transceiver 21 or the control device 22, it cannot be clearly determined from these two possible positions at which of the positions P10, P11 the mobile transceiver 11 or the mobile unit 10 is actually located.

[0072] The simplified representation from Fig. 3 can be found with regard to its essential elements in Fig. 4 again, wherein in addition to the first antenna array 23A, a second antenna array 23B is also shown, which is constructed identically to the first antenna array 23A, but is arranged orthogonally to one another with respect to the planes E1, E2 or with respect to the antenna reference planes E1, E2.

[0073] As shown, the different positioning and orientations of the antenna arrays 23A, 23B result in two positions P10, P11, P12 being determinable from the signal S received by the antennas 23 of the respective antenna array 23A, 23B, which positions belong to the mobile unit 10 or its mobile transceiver 11 and two “ghost transceivers” 12.

[0074] By comparing the angles Φ and reception angles Φ1, Φ2 determined by the two antenna arrays 23A, 23B with the respective reference lines B1, B2 belonging to the antenna reference plane E1, E2, as shown in Fig. 6, the quadrant of the polar coordinate system in which the mobile unit 10 or its mobile transceiver 11 is actually arranged can be determined.

[0075] In order to avoid having to use two comparatively expensive control devices 22 for evaluating the data or two comparatively expensive transceiver electronics 25, a switching device 24 is also provided which alternately connects the two antenna arrays 23A, 23B to the transceiver electronics 25 upon reception of a signal S or via the transceiver electronics 25 to the control device 22, so that consequently all data sent via the signal S are received, but for this purpose all the aforementioned positions can be determined.

[0076] In Fig. 5, the measurement error or error tolerance of the reception angles Φ1, Φ2 is plotted as the ordinate over the reception angles Φ1, Φ2 around the reference line B1, B2 running orthogonal to the respective antenna reference plane as the abscissa. As can be seen, the measurement error increases significantly above ±45°, so that the predetermined angular range is preferably selected to be ±45° around the reference line B1, B2 running perpendicular to the respective antenna reference plane E1, E2.

[0077] In Fig. 6 shows a preferred embodiment with exactly two antenna arrays 23A, 23B, each having exactly two antennas 23. The antennas 23 of the respective antenna arrays 23A, 23B lie on a respective antenna reference plane E1, E2, wherein the antenna reference planes E1, E2 are orthogonal to one another.

[0078] The coordinate origin of the common polar coordinate system lies at the intersection point of the antenna reference planes E1, E2.

[0079] In the selected representation from above, the reference lines B1, B2 coincide with the other antenna reference plane E1, E2, as can be seen, for example, from the reception angles Φ1, Φ2 shown.

[0080] Furthermore, the coordinate origin of the common polar coordinate system lies at the intersection point of the two antenna reference planes E1, E2, so that the antenna reference planes E1, E2 separate the quadrants Q1, Q2, Q3, Q4 from each other.

[0081] As with regard to Fig. 3, the actual quadrant in which the position of the mobile unit 10 lies can be determined by a simple comparison of the angles with the angular ranges assigned to the respective quadrants.

[0082] However, it is essential that the determination of the angle Φ should be improved so that the position of the mobile unit 10 can be specified with greater accuracy.

[0083] Starting from Fig. 6, a first reception angle Φ1 is determined by the signal S received by the antennas 23 of the first antenna array 23A or its signal components, which corresponds to the smallest angle between the reference line B1 perpendicular to the antenna reference plane E1 and an auxiliary line from the polar coordinate system of the first antenna array 23A and here at the same time the common polar coordinate system to the mobile transceiver 11.

[0084] Furthermore, a second reception angle Φ2 is determined by the signal S received by the antennas 23 of the second antenna array 23B or its signal components, which corresponds to the smallest angle between the reference line B2 perpendicular to the antenna reference plane E2 and an auxiliary line from the polar coordinate system of the second antenna array 23B and here at the same time the common polar coordinate system to the mobile transceiver 11.

[0085] As already shown in the schematic Fig. 6, the first reception angle Φ1 is large and the second reception angle Φ2 is small, so that the use of the smaller reception angle Φ2 leads to a smaller measurement error.

[0086] This also results from the fact that each antenna array 23A, 23B is assigned a predetermined, preferred angular range W1, W2, wherein the preferred angular ranges W1, W2 in the present case are ±45° around the respective reference line B1, B2.

[0087] Consequently, the second reception angle Φ2 lies within the associated preferred angle range W2, whereas the first reception angle Φ1 lies outside the associated preferred angle range W1.

[0088] The determination of the angle Φ of the position of the mobile unit is therefore based on the second reception angle Φ2. Depending on the orientation of the common polar coordinate system and any possible deviations in the positioning of the coordinate origins, a transformation of the respectively selected reception angle Φ1, Φ2 into the angle Φ of the position is required.

[0089] An exemplary procedure for determining the position of the mobile unit 10 is shown in Fig. 7, wherein the control device 22 can be designed accordingly to carry out a method based thereon or at least some of the steps.

[0090] According to the Fig. The procedure shown in Figure 7 and based on a flow chart includes, in particular, the following steps: Step A The stationary unit 20 or the control device 22 determines a first reception angle Φ1 from signals S received by the first antenna array 23A. Step B Switching by means of the switching device 24 so that the transceiver electronics 25 is no longer connected to the first antenna array 23A, but to the second antenna array 23B. Step C The stationary unit 20 or the control device 22 determines a second reception angle Φ2 from signals S received by the second antenna array 23B. Step D: The stationary unit 20 or the control device 22 checks whether the first reception angle Φ1 lies within the angular range W1 assigned to the first antenna array 23A. If no, continue to step E. If yes, continue to step F. Step E The second reception angle Φ2 is stored to determine the angle Φ of the position of the mobile unit 10. Step F The first reception angle Φ1 is stored to determine the angle Φ of the position of the mobile unit 10. Step G The angle Φ is determined from the reception angle Φ1, Φ2 stored for determining the angle Φ, whereby the stored reception angle Φ1, Φ2 corresponds to the angle Φ or is transformed into it taking into account a predetermined angular offset. Step H: Is the first reception angle Φ1 between 0° and +90° and the second reception angle Φ2 between 0° and -90°, and thus, for example, in the second quadrant Q2 of the common polar coordinate system? If yes, proceed to step J. If no, proceed to step K. Step J The angle Φ corresponds to the sum of 0° as angular offset and the reception angle Φ1, Φ2 stored to determine the angle Φ. Step K: Is the first reception angle Φ1 between 0° and +90° and the second reception angle Φ2 between 0° and +90°, and thus, for example, in the first quadrant Q1 of the common polar coordinate system? If yes, proceed to step L. If no, proceed to step M. Step L The angle Φ corresponds to the sum of 90° as angular offset and the reception angle Φ1, Φ2 stored to determine the angle Φ. Step M: Is the first reception angle Φ1 between 0° and -90° and the second reception angle Φ2 between 0° and +90°, and thus, for example, in the fourth quadrant Q4 of the common polar coordinate system? If yes, proceed to step N. If no, proceed to step O. Step N The angle Φ corresponds to the sum of 180° as angular offset and the reception angle Φ1, Φ2 stored to determine the angle Φ. Step O The first reception angle Φ1 and the second reception angle Φ2 lie in the third quadrant Q3. The angle Φ corresponds to the sum of 270° as the angular offset and the reception angles Φ1, Φ2 stored to determine the angle Φ. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2023 / 222462 A1

[0003] DE 10 2020 114 403 A1

[0003]

Claims

[1] Access control system (1) for buildings (2) with a stationary unit (20) and a mobile unit (10), wherein the mobile unit (10) has a mobile transceiver (11) which is designed to wirelessly and encryptedly transmit signals (S) for authentication and authorization of the mobile unit (10) with respect to the stationary unit (20) and for control of the stationary unit (20) by the mobile unit (10) to a stationary transceiver (21) of the stationary unit (20), which has at least a first antenna array (23A) and a second antenna array (23B), wherein the antennas (23) of the respective antenna array (23A, 23B) lie in a common antenna reference plane (E1, E2) and the antenna reference planes (E1, E2) of the antenna arrays (23A, 23B) are tilted relative to one another, wherein the stationary unit (20) comprises a control device (22) which is designed to determine a distance (r) and an angle (Φ) as a position of the mobile unit (10) relative to the stationary unit (20) from signals (S) transmitted from the mobile transceiver (11) to the stationary transceiver (21), so that the position of the mobile unit (10) can be specified as polar coordinates of a polar coordinate system lying in a horizontal plane, in whose coordinate origin the stationary transceiver (21) is arranged, and to control a function when a control command for triggering the function is transmitted to the stationary unit (20) by a mobile unit (10) authenticated and authorized by the stationary unit (20) and / or the position of the mobile unit (10) is within a predetermined access area (30), and wherein the control device (22) is designed to determine a respective reception angle (Φ1, Φ2) specific for the respective antenna array (23A, 23B) from signals (S) transmitted from the mobile transceiver (11) to the stationary transceiver (21) and received by the antenna arrays (23A, 23B), to determine a quadrant of the polar coordinate system in which the position lies from the reception angles (Φ1, Φ2), and to determine the angle (Φ) of the position from the reception angle (Φ1, Φ2), which lies in an angular range predetermined for the respective antenna array (23A, 23B) with a predetermined low measurement error, and the quadrant. [2] Access control system according to claim 1, wherein the first antenna array (23A) has two and / or exactly two antennas (23) and all antennas (23) of the first antenna array (23A) extend in the common first antenna reference plane (E1) and the second antenna array (23A) has two and / or exactly two antennas (23) and all antennas (23) of the second antenna array (23B) extend in a common second antenna reference plane (E2). [3] Access control system according to claim 1 or 2, wherein exactly two antenna arrays (23A, 23B) are provided, the antenna reference planes (E1, E2) of which are orthogonal to one another, and wherein the control device (22) is designed to determine exclusively from the reception angle (Φ1, Φ2) the angle (Φ) which, with respect to the respectively associated antenna reference plane (E1, E2), lies in an angular range of ±45° around a reference line running perpendicularly through the respective antenna reference plane (E1, E2). [4] Access control systems according to the preceding claim, wherein the control device (22) is designed to determine the position as lying in the quadrant of the polar coordinate system if both a first reception angle (Φ1) specific to the first antenna array (23A) and a second reception angle (Φ2) specific to the second antenna array (23B) lie in the quadrant. [5] Access control system according to one of the preceding claims, wherein the control device (22) is designed to determine from signals (S) transmitted from the mobile transceiver (11) to the stationary transceiver (21) and received by the antenna arrays (23A, 23B) a respective reception distance specific to the respective antenna array (23A, 23B) from which the signal (S) was received, and to determine the distance (r) of the position from the reception distances. [6] Access control system according to the preceding claim, wherein the control device is designed to determine an average value for the distance (r) from at least two distances (r). [7] Access control system according to claims 2 to 6, wherein the two antennas (23) of a respective antenna array (23A, 23B) each have a respective previously known distance (d) from each other in the horizontal plane, and wherein the control device (22) is designed to determine the respective reception angles (Φ1, Φ2) from a phase shift (α) between the signal (S) received at least partially at the two antennas (23) of the respective antenna array (23A, 23B) and the distance (d). [8] Access control system according to one of claims 2 to 7, wherein all antennas (23) of the respective antenna array (23A, 23B) are formed on a common printed circuit board determining the respective antenna reference plane (E1, E2). [9] Access control system according to one of the preceding claims, further comprising a switching device (24) connected between a transceiver electronics (25) of the stationary transceiver (21) and the antenna arrays (23A, 23B), which switching device is designed to alternately switch the transceiver electronics (25) of the stationary transceiver (21) to connect it to the antenna arrays (23A, 23B) while the signal (S) is being received, so that the antenna arrays (23A, 23B) each receive a part of the signal (S) and the signal (S) received via the antenna arrays (23A, 23B) is transmitted to the transceiver electronics (25) of the stationary transceiver (21) and / or the control device (22).

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