Surface pressure sensor

Abstract

The invention relates to a surface pressure sensor having a sensor mat (10), an optical fibre arrangement (20), an optical sensor unit (60) and an evaluation unit (110), wherein the optical fibre arrangement (20) has a column fibre arrangement (30) and a row fibre arrangement (40) having column fibres (31n) and row fibres (41n) which intersect at intersection points (51n) and provide an intersection point matrix (50). In the event of a force acting as a result of surface pressure, the fibres (31n, 41n) undergo deformation, thereby forming a light-transmitting touch contact surface (52). By means of the optical sensor unit (60), a light signal is introduced into each of the column fibres (31n) by the light source arrangement (70) of the optical sensor unit, and the transmitted portion of the light signal on the column fibres and the portion of the light signal coupled into the row fibres (41n) via the touch contact surfaces (52) are detected by column and row photosensor arrangements (80, 90, 100) of the optical sensor unit (60) and subsequently evaluated by the evaluation unit (110), and the distribution of the surface pressure is thus determined in a spatially resolved manner for each intersection point (51n). The invention also relates to a method for the spatially resolved detection of a surface pressure.

Description

[0001] Surface pressure sensor

[0002] The invention relates to a fiber-optic spatially resolved area pressure sensor, in particular with continuous evaluation.

[0003] Pressure sensors for measuring surface pressure using a fiber optic principle are known in principle from the prior art.

[0004] US Patent 4,733,068 A describes a touch sensor with intersecting optical fibers. The fibers in the first direction are actively optical, while the transversely arranged and thus intersecting fibers are light-detecting. An intermediate layer is positioned between the two fiber groups, featuring recesses at the intersection points. When a transverse force is applied, the intermediate layer is compressed, bringing the fibers into contact with each other. This couples light from the actively optical fibers into the light-detecting fibers. Sensors detect the coupled light at the light-detecting fibers, identifying the intersection point and thus localizing the area of ​​force application. A disadvantage of this design is its complex construction, particularly the requirement for a specially designed intermediate layer and the precise positioning of the fibers.Furthermore, there are strict limits to sensitivity, resolution according to the magnitude of the acting force, and miniaturization.

[0005] Furthermore, EP 3 420 331 B1 discloses an optical waveguide system for two-dimensional position detection, which is also based on the principle of intersecting optical fibers. A grid of intersection points is generated by a plurality of optical fibers arranged in rows and columns. To increase the light coupling, it is proposed to increase the force acting between the intersecting optical fibers by means of a mechanical structure in the form of a rigid ring around each intersection point. The coupled light is then read out in a known manner, and thus the intersection point is subjected to a force input.

[0006] Confirmation copy effect recognized. Disadvantages of this solution include the high manufacturing costs and the limited miniaturization.

[0007] Another solution is proposed by US 5,293,039, which, however, does not involve any crossing of the optical fibers. The optical fibers are arranged in a meandering and simultaneously wave-like pattern on a flat substrate. When a force is applied, the waveform is reduced, thus altering the optical conductivity. The force is detected by identifying this change in optical conductivity. A disadvantage of this solution is that it cannot provide localization of the force.

[0008] The prior art also proposes that, in order to improve light coupling in transverse fibers, at least one of the fibers should be provided with a special sheath.

[0009] The object of the invention is to provide a surface pressure sensor with high sensitivity and high two-dimensional spatial resolution, which enables both accurate localization of the pressure and detection of the pressure level, is easily scalable in size and resolution, has high electromagnetic compatibility and can be manufactured cost-effectively.

[0010] The problem is solved by the features listed in claim 1. Preferred embodiments are set forth in the dependent claims.

[0011] The surface pressure sensor according to the invention is a fiber optic sensor which comprises as basic components a sensor mat, a fiber optic arrangement, an optosensor unit and an evaluation unit.

[0012] The sensor mat is a planar structure. It forms a sensor mat plane. This sensor mat plane can be flat, but depending on the application requirements, it can also be curved or flexible. The direction of the force acting due to the pressure to be detected is oriented perpendicular to the sensor mat plane, capturing both orthogonal and oblique directions. The sensor mat can be structured, for example, as a fabric, a carrier film, or in other ways.

[0013] In special configurations, it can also be formed entirely or partially by the optical fibers of the fiber optic array and may include a tension frame. Furthermore, for specific applications, it is possible to apply a foam layer or a layer of similar material as a buffer layer.

[0014] The optical fiber arrangement comprises the column fiber arrangement and the row fiber arrangement with intersecting optical fibers and is arranged in the sensor mat plane.

[0015] The optical fibers are arranged in columns and rows and provide a matrix through the intersection points.

[0016] The column fiber arrangement comprises a plurality of column fibers. The column fibers are arranged longitudinally relative to each other. They can, in particular, be arranged parallel to each other. Each has a first column fiber end and a second column fiber end. The row fiber arrangement is configured in a similar manner to the column fiber arrangement. The row fiber arrangement comprises a plurality of row fibers, which are also arranged longitudinally relative to each other and each have a first row fiber end and a second row fiber end.

[0017] Essential to the invention is the arrangement of the column fibers and the row fibers transversely to each other in the plane of the sensor mat, such that they intersect and form a plurality of intersection points. The feature of the transverse arrangement includes both right-angled arrangements and arrangements at angles smaller than 90 degrees. The intersection points together constitute an intersection point matrix. Each intersection point is defined in the intersection point matrix by both intersecting fibers, i.e., the column fiber, also referred to as the N-fiber, and the corresponding row fiber, also referred to as the M-fiber. Each intersection point is located in an influence zone of a specific area of ​​the sensor mat, hereinafter also referred to as an area section, and thus represents this area section of the sensor mat, so that the pressure acting in this area section can be determined from the acting force.Preferably, the intersection points are equidistant from each other at a distance of 0.1 cm to 100 cm and particularly preferably from 1 cm to 10 cm.

[0018] For the purposes of the present invention, the slit fibers and the line fibers are collectively referred to as the optical fibers or, more simply, as the fibers. The designation as slit fiber or line fiber does not specify their spatial orientation in terms of a vertical or horizontal arrangement. Preferably, all optical fibers are structurally identical. However, the slit fibers and the line fibers can also differ structurally, particularly in terms of material, shape, and size. Preferably, the fibers have a circular cross-section with a diameter of 0.02 mm to 20 mm, and particularly preferably with a diameter of 0.2 mm to 2 mm. They comprise a light-conducting and preferably polymeric material such as thermoplastic polyurethane (TPU) or polymethyl methacrylate (PMMA).

[0019] In the context of the present invention, the numbers such as first and second are used for the purpose of differentiation and do not express any ranking or other hierarchy.

[0020] At the intersection points, the optical fibers are positioned such that, when a force is applied perpendicular to the sensor mat plane, they come into contact with each other. According to the invention, this contact, when a force is applied, firstly generates a cross-sectional deformation and, secondly, creates a light-transmitting contact surface. The cross-sectional deformation is present in at least one of the two crossing fibers and preferably in both. The cross-sectional deformation causes a change in the geometry of the inner reflective surface of the fiber, so that an input light signal introduced at the first end of the fiber is modified and transmitted to the second end of the fiber as a modified light signal, referred to here as the transmission light signal. To enable cross-sectional deformation, the fibers are made of an elastically deformable material.

[0021] The light-transmitting contact surface is the area where the molded surface sections of the intersecting fibers directly touch each other. The cross-sectional deformation is therefore a prerequisite for the formation of the light-transmitting contact surface.

[0022] The contact surface is designed to transmit a portion of the input light signal into the crossing line fiber. For the purposes of the present invention, this is hereinafter also referred to as coupling or cross-coupling. The portion of the light signal now present in the line fiber due to the coupling is called the coupling light signal. Part of this is directed as a first coupling light signal to the first line fiber end, and another part as a second coupling light signal to a second line fiber end.

[0023] The optosensor unit according to the invention comprises, firstly, a light source arrangement and, secondly, several photosensor arrangements. The photosensor arrangements detect light signals present at the respective fiber ends and are configured as, on the one hand, a column photosensor arrangement and, on the other hand, as two row photosensor arrangements. The row photosensor arrangements are referred to as the first row photosensor arrangement and the second row photosensor arrangement. The photosensors of the photosensor arrangements convert the received light signal into an electrical signal. The photosensors are preferably photodiodes.The light source arrangement comprises a plurality of light signal sources, each assigned to one of the first fiber ends of the slit fibers, also referred to as illuminated fibers, and each introducing a light signal there, which, according to the present invention, is referred to as the introduction light signal or the N-transmit signal. Preferably, the light signal sources are light-emitting diodes (LEDs). The light signal sources are hereinafter also referred to as N-signal sources. The multiple light signal sources can also be structurally combined, in particular as a pixel light source, so that each fiber end is assigned a light-emitting pixel.

[0024] The slit photosensor array comprises multiple slit photosensors. These are assigned to the respective second end of the slit fibers, referred to here as the second slit fiber ends. They serve to detect the light signal transmitted through the slit fibers, referred to here as the transmitted light signal. The signal output by these photosensors is called the slit photosensor signal or N-signal.

[0025] Furthermore, the two identical line photosensor arrangements are arranged at the two line fiber ends of the line fibers, also referred to as unilluminated fibers.

[0026] The first line photosensor arrangement comprises a plurality of first line photosensors, each assigned to the respective first line fiber end and configured to detect the first coupling light signal and output it as the first line photosensor signal. Similarly, the second line photosensor arrangement comprises a plurality of second line photosensors, each assigned to the respective second line fiber end and configured to detect the second coupling light signal and output it as the second line photosensor signal. These line photosensor signals are subsequently referred to as M-signals.

[0027] Like the light signal sources, the multiple photosensors can be advantageously combined in a single configuration. In particular, the multiple photosensors can be configured as a pixel light sensor, for example, a CCD camera, to which a fiber bundle is connected, with each fiber assigned to a specific pixel. Both column and row photosensor arrangements can function as a pixel light sensor. The photosensor arrangements can also be partially or completely comprised of a common pixel light sensor, in which specific pixel groups are assigned to the respective photosensor arrangements.

[0028] The evaluation unit analyzes the photosensor signals to detect the intersection points where a force is applied, resulting in surface pressure. The evaluation unit is preferably designed as a computer or other electronic circuit. Preferably, it also functions as a controller, the control unit for the light sources.

[0029] In a particularly advantageous further development, the evaluation unit is designed to evaluate the N signals and the M signals according to a channel estimation of an M1 MO (multiple input-multiple output) system. Here, the input signals to the column fibers are considered M inputs, and the measured sensor signals at the N line fibers are considered outputs. Using test signals, an MxN coupling matrix can be determined in the same way as in MIMO systems with M inputs and N outputs. The difference from the MIMO system is that this matrix is ​​not used to correct the transmission signals, but rather represents the coupling at the fibers itself, which is to be measured. Since MIMO systems are widely used in transmission systems over various media such as radio, two-wire lines, or optical fibers, suitable processors and system technology are readily available.

[0030] The evaluation unit is connected to the photosensors of all three photosensor arrays: the column photosensor array and the two row photosensor arrays. The evaluation unit thus receives both the column photosensor signals, which, as N-signals, provide information about transmission in the light-carrying column fibers, and the row photosensor signals, which, as M-signals, provide information about coupling into the transversely arranged row fibers.

[0031] According to the invention, both the N-signals and the M-signals are related to each other as received signals, and these are also related to the N-transmitted signals. This allows the crossing points subjected to a force to be detected based on the N-fibers and M-fibers involved.

[0032] In particular, it was found that including the transmitted N-signals significantly improves the evaluation quality. This is because the coupling rate is very low and, according to current knowledge, does not exceed a single-digit percentage of the input light signal, even under high force. The low signal-to-noise ratio achieved when evaluating the two M-signals can be considerably increased by including the N-signal. Particularly advantageously, in addition to the N-signal as the transmission signal and the M-signals as the coupling signal, the N-input signal can also be used to evaluate the received signals.

[0033] Such arrangements can also be viewed as MIMO systems with N inputs and (N+M) outputs, and by determining the coupling matrix, not only the overcoupling but also the associated increased damping can be determined. The combination of these two pieces of information allows for a more accurate reconstruction of the force application than evaluating the overcoupling alone.

[0034] According to a first advantageous further development, the surface pressure sensor is characterized in that the evaluation unit is designed to determine the magnitude of the applied force by means of the ratio of the column photosensor signals and the row photosensor signals for the intersection points subjected to a force.

[0035] It was found that, with suitable material selection and fiber dimensions, an essentially linear relationship can be established between the applied force and the signal strength of the coupled M-signals. After appropriate calibration, the pressure of the relevant area section at each intersection point can be determined based on this.

[0036] According to a further advantageous embodiment, the surface pressure sensor is characterized in that the column fibers and the row fibers are arranged at an angle of 30 degrees to 60 degrees to each other.

[0037] By significantly deviating from an orthogonal crossing angle, preferably at an angle of 45 degrees, the very low coupling signal rate, which was found to be a disadvantage in the prior art, can be considerably improved.

[0038] In a further advantageous embodiment, the surface pressure sensor is characterized in that the light signal sources of the light source arrangement are designed for a sequential introduction of the respective introduction light signal.

[0039] By sequentially controlling the light signal sources, the received M-signals can be reliably assigned to a specific N-transmitted signal, thus identifying the N-fiber. Since the M-fiber is also known from the M-signal, the relevant crossing point and therefore the corresponding area segment can also be identified.

[0040] According to another advantageous embodiment, the surface pressure sensor is characterized in that the light signal sources of the light source arrangement are designed to introduce an introduction light signal that is identifiable by means of wavelength or by means of modulation.

[0041] This advanced training makes it possible to detect the respective N-fiber as the source of a read-out M-signal, even with a continuous introduction of a light signal, and thus to identify the crossing point.

[0042] According to a further advantageous development, the surface pressure sensor is characterized by the fact that the sensor mat is designed as a textile fabric and that the optical fibers are integrated into the textile fabric.

[0043] The textile fabric determines the relative positions of the fibers in both the columnar and row fiber arrangements. At the same time, it advantageously provides mechanical protection for the fibers.

[0044] According to another advantageous embodiment, the surface pressure sensor is characterized in that the sensor mat is formed by the optical fibers.

[0045] Preferably, in this further development, the optical fibers are arranged in relation to each other in the manner of a fabric.

[0046] According to another advantageous embodiment, the surface pressure sensor is characterized in that the optical fibers extend beyond the sensor mat and are bundled into an optical fiber strand outside the sensor mat.

[0047] This advanced training advantageously enables the provision of an area sensor that exhibits high reliability even under very strong electromagnetic fields. This is achieved by arranging the electromagnetically sensitive components, such as the evaluation unit, as well as the light signal sources and photosensors, completely spatially separated from the detection area formed by the sensor mat. For example, a safety mat can be provided for use in a magnetic resonance imaging (MRI) scanner that detects movements of the patient lying on the safety mat during imaging in real time based on spatially resolved pressure readings. By assigning these readings to the respective image slices, displacements in the image slices can be interpreted and corrected.

[0048] Conversely, such a surface pressure sensor can also be advantageously used in an electromagnetically particularly sensitive environment without disturbing it.

[0049] Another particular advantage of the area sensor according to this training is that it can be used safely in potentially explosive environments.

[0050] According to another aspect, the invention relates to a method for the spatially resolved detection of surface pressure. The descriptions of the intended use and operation of the surface pressure sensor apply accordingly to the method according to the invention.

[0051] The invention is described as an embodiment by reference to

[0052] Fig. 1 Isometric view in schematic representation

[0053] Fig. 2 Isometric view in schematic representation at acute angle

[0054] optical fiber arrangement

[0055] Fig. 3 Schematic representation of an acute-angled optical fiber arrangement

[0056] Fig. 4 Schematic representation of the detection of the coupling light signal at both ends of the line fiber, explained in more detail.

[0057] In this context, identical reference symbols in different figures refer to the same features or components. These reference symbols are used in the description even if they are not shown in the figure in question.

[0058] Fig. 1 shows, in a first embodiment with a right-angled arrangement of the line fibers 41n to the column fibers 31n, an area pressure sensor in which the sensor mat 10 is formed by the fibers 31n, 41n of the optical fiber assembly 20 itself. In an alternative example – not shown here – the optical fiber assembly 20 is embedded in a support structure that protects the optical fiber assembly.

[0059] The fibers 31n and 41n are arranged in a crisscrossing pattern. Crossover points 51n are located at the intersections, and these crossover points together form the crossover point matrix 50. If a force acts perpendicular to the sensor mat plane due to surface pressure, the column fibers 31n and the row fibers 41n come into contact with each other at the crossover points 51n. The force represents the surface pressure acting on a detection area of ​​one or more crossover points 51n and is illustrated in Fig. 1 by the three arrows Fp shown in bold. In this embodiment, the sensor mat plane in Fig. 1 is represented by the grid formed by dashed lines. If the surface pressure varies locally, the force acting on the crossover points 51n also varies accordingly.Fibers 31n, 41n are made of a light-conducting and elastically deformable material. Under sufficiently high surface pressure, and thus sufficiently high force, both fibers 31n, 41n deform at the respective intersection point 51n at the contact point and conform to one another in such a way that a contact surface 52 is formed. The area of ​​the contact surface 52 correlates with the magnitude of the applied force. A light signal – represented here by the white-filled arrows – is introduced into the respective first end of the slit fiber 32 by means of the light source arrangement 70, which in the exemplary embodiment is formed by light signal sources 71n in the form of LEDs.If a crossing point 51n with a contact surface 52 is located along a slit fiber 31n, a portion of the light introduced as the input light signal passes through the contact surface into the intersecting line fiber 41n. The transmitted light is then coupled as an input signal in the line fiber 41n to the two line fiber ends 42, 43. The signal strength of the input signal can differ between the two line fiber ends 42, 43, particularly in an acute-angled arrangement as shown in Figures 2 and 3, due to the asymmetrical internal geometry resulting from the deformation. Simultaneously, the light signal transmitted to the second line fiber end 33 is altered by both the coupling out of a portion of the input light signal and the deformation, and thus the changed internal geometry, of the slit fiber 31n, and is present there as a transmission light signal.

[0060] In the embodiment shown in Fig. 1, the coupling signal is detected both at the first line fiber end 42 – here by the first line photosensor arrangement 90 with the first line photosensors 91n – and at the second line fiber end 43 – here by the second line photosensor arrangement 100 with the second line photosensors 101n. In addition, the transmitted light signal is also detected at the second column fiber end 33 – here by the column photosensor arrangement 80 with the column photosensors 81n. All photosensors 81n, 91n, 101n are designed as photodiodes in this embodiment.

[0061] The light source arrangement 70, the column photosensor arrangement 80, and the first and second row photosensor arrangements 90, 100 together form the optosensor unit 60. All of the aforementioned components 70, 80, 90, 100 of the optosensor unit 60 are connected to the evaluation unit 110, although the connection is not shown in Fig. 1 for clarity. In the exemplary embodiment, the evaluation unit 110 is configured to evaluate the signal strengths of the coupling light signals at the two row fiber ends 42, 43, as well as the transmission light signal at the second column fiber ends 33, and to relate them to each other. This allows the force applied at each intersection point 51 n to be selectively determined, and thus the local distribution of a surface pressure acting on the surface pressure sensor to be detected.Furthermore, the evaluation unit 110 is equipped to output this detection result as a data set or directly visually or in another form.

[0062] Fig. 2 shows a further embodiment in which, in a preferred configuration, the line fibers 41n are arranged parallel to one another and at an acute angle α of approximately 60 degrees to the column fibers 31n; the column fibers 31n are also arranged parallel to one another, resulting in a diamond-shaped intersection matrix 50. Due to the acute-angled arrangement, a larger and simultaneously asymmetrical contact area 52 is formed for the same force, which is shown here hidden by the oval outlined with a dashed line. This advantageously makes it possible to provide a signal strength of the coupling signal by detecting only the line fiber end opposite the angle α, enabling a reliable determination of the acting force by the surface pressure.

[0063] Fig. 3 additionally shows a schematic for an acute-angled arrangement with the coupling light signal being detected only at one end of the line fiber 42. According to Fig. 3, in addition to the light source arrangement 70 with the light signal sources 71 n, only the first line photosensor arrangement 90 with the first line photosensors 91 n is present.

[0064] Fig. 4 shows an alternative embodiment in which, as in Fig. 1, the column fibers 31n and the row fibers 41n are arranged at right angles, but in the embodiment according to Fig. 4, the area sensor is designed without detecting the transmitted light signal. Accordingly, only the two row photosensor arrangements 90, 100 are present. Reference numerals used

[0065] 10 Sensor mat

[0066] 20 Optical fiber arrangement

[0067] 30 Split fiber arrangement

[0068] 31 n split fiber

[0069] 32 first split fiber end

[0070] 33 second split fiber end

[0071] 40 row fiber arrangement

[0072] 41 n line fiber

[0073] 42 first row fiber end

[0074] 43 second line fiber end

[0075] 50 Intersection point matrix

[0076] 51 n Intersection point

[0077] 52 Contact surface

[0078] 60 Optosensor unit

[0079] 70 Light source arrangement

[0080] 71 n Light signal source

[0081] 80 column photosensor array

[0082] 81 n column photosensor

[0083] 90 first line photosensor array

[0084] 91 n first line photosensor

[0085] 100 second line photosensor array

[0086] 101 n second line photosensor

[0087] 110 evaluation unit a angle alpha

Claims

Patent claims 1. Area pressure sensor comprising a sensor mat (10), an optical fiber arrangement (20), an optosensor unit (60), and an evaluation unit (110), wherein the optical fiber arrangement (20) is associated with the sensor mat and comprises a column fiber arrangement (30) and a row fiber arrangement (40), wherein the column fiber arrangement (30) comprises a plurality of column fibers (31 n) arranged longitudinally to one another and each having a first column fiber end (32) and a second column fiber end (33), wherein the row fiber arrangement (40) comprises a plurality of row fibers (41 n) arranged longitudinally to one another and each having a first row fiber end (42) and a second row fiber end (43), wherein the column fibers (31 n) and the row fibers (41 n) are arranged in a sensor mat plane (11) transversely to one another and intersecting each other, forming a plurality of intersection points (51 n). are,wherein the crossing points (51 n) form a crossing point matrix (50) and wherein the optical fibers (31 n, 41 n) at the crossing points (51 n) are formed for contact by forming a cross-sectional deformation and a light-transmitting contact surface (52) between the crossing optical fibers (31 n 41 n) when a force is applied transversely to the sensor mat plane (11), wherein the cross-sectional deformation of the crossing slit fibers (31 n) is formed to modify an input light signal introduced at the first slit fiber end (32) and to guide it as a transmission light signal to the second slit fiber end (33) and wherein the contact surface (52) is formed to transmit a part of the input light signal into the crossing line fiber (41 n) and to transmit it as a first coupling light signal to the first line fiber end (32), and to direct as a second coupling light signal to a second line fiber end, wherein the optosensor unit (60) comprises a light source arrangement (70), a column photosensor arrangement (80), a first line photosensor arrangement (90), and a second line photosensor arrangement (100), wherein the light source arrangement (70) comprises a plurality of light signal sources (71n), each assigned to one of the first column fiber ends (32) and configured to introduce a coupling light signal, wherein the column photosensor arrangement (80) comprises a plurality of column photosensors (81n) assigned to the respective second column fiber end (33) and configured to detect the transmission light signal and output it as a column photosensor signal, wherein the first line photosensor arrangement (90) comprises a plurality of first line photosensors (91n),the column photosensor signals (42) are assigned to the respective first line fiber end and are configured to detect the first coupling light signal and output it as the first line photosensor signal, wherein the second line photosensor arrangement (100) comprises a plurality of second line photosensors (101n) assigned to the respective second line fiber end (43) and configured to detect the second coupling light signal and output it as the second line photosensor signal, wherein the evaluation unit (110) is connected to the photosensors (81n, 91n, 101n) and is configured to detect and output the force-actuated intersection points (51n) of the intersection point matrix (50) by means of the column photosensor signals and the line photosensor signals.

2. Surface pressure sensor according to claim 1, characterized in that the evaluation unit (110) is configured to determine the ratio of the column photosensor signals and the row photosensor signals for the area with to detect and output the magnitude of the applied force at the intersection points (51 n) subjected to a force.

3. Surface pressure sensor according to one of the preceding claims, characterized in that the column fibers (31 n) and the row fibers (41 n) are arranged to each other at an angle alpha of 30 degrees to 60 degrees.

4. Surface pressure sensor according to one of the preceding claims, characterized in that the light signal sources (71 n) of the light source arrangement (70) are configured for a sequential introduction of the respective introduction light signal.

5. Surface pressure sensor according to one of the preceding claims, characterized in that the light signal sources (71 n) of the light source arrangement (70) are configured to introduce an introduction light signal identifiable by wavelength or by modulation.

6. Surface pressure sensor according to one of the preceding claims, characterized in that the sensor mat (10) is designed as a textile fabric and that the optical fibers (31 n, 41 n) are integrated into the textile fabric.

7. Surface pressure sensor according to one of the preceding claims, characterized in that the sensor mat (10) is formed by the optical fibers (31 n, 41 n).

8. Surface pressure sensor according to one of the preceding claims, characterized in that the optical fibers (31 n, 41 n) extend beyond the sensor mat and are bundled into an optical fiber strand outside the sensor mat.

9. Method for spatially resolved detection of surface pressure using a surface pressure sensor, wherein the surface pressure sensor is configured according to any one of the preceding claims 1 to 8, comprising the following method steps: a) generating a cross-sectional deformation of intersecting column fibers (31 n) and row fibers (41 n) at intersection points (51 n) and forming a light-transmitting contact surface (52) by means of a force resulting from the surface pressure, b) generating introduction light signals by means of the light source arrangement (70) and introducing them into the column fibers (31 n) at their first column fiber ends (32) as N-transmit signals,c) Detection of the N-transmit signals transmitted by the column fibers (31 n) and modified by the cross-sectional deformations and contact surfaces (52) as N-signals by the column photosensor unit and provision as column sensor data for transmission and transmission of the column sensor data to the evaluation unit (110), d) Detection of the components of the N-transmit signals transmitted by the contact surfaces from the column fibers (31 n) to the row fibers (41 n) as M-signals at at least one of the row fiber ends (42, 43) by the respective row photosensor unit (90, 100) and provision as row sensor data for transmission and transmission of the row sensor data to the evaluation unit (110), e) Evaluating both the column sensor data and the row sensor data, and by the evaluation unit, determining the strength of the light signal transmission for each of the intersection points 51 n as a representation of the force acting on the respective intersection point 51 n from the surface pressure

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