Sensor arrangement

Abstract

To provide a sensor arrangement constituted so as to be small, solid, low cost and high in measurement accuracy, and a method for manufacturing the sensor arrangement.SOLUTION: A sensor arrangement (1) for measuring power and / or torque includes: a plurality of sensor parts (11) having each sensor (13) and arranged around a first axis (3); and a plurality of connection pieces (21) for connecting the two adjacent sensor parts (11) to each other. A connection (33) between the connection piece (21) and a first sensor part of the adjacent sensor parts is provided in a first axis area (23), and the connection piece (21) extends toward a second axis area (25) different from the first axis area (23) in a gap (17) between the adjacent sensor parts.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a sensor array for measuring force or torque and a method for manufacturing the sensor array.

Background Art

[0002] The prior art discloses sensor arrays capable of measuring force or torque. In particular, for applications in medical engineering, such as for minimally invasive surgical telemanipulators, or for applications in robotics, such as for industrial gripper systems, such sensor arrays can be used to measure or control force or torque. For example, a sensor array can be used to provide tactile feedback regarding a gripper arm or manipulation arm, or an end effector provided thereon. For many applications, the smallest and least expensive force and torque sensors are advantageous.

[0003] However, known sensor arrays have limitations, particularly with respect to miniaturization of the sensor array. Alternatively, or in addition, known sensor arrays may have limitations with respect to the measurement accuracy or robustness of the sensor array, particularly when the size of the sensor array is gradually reduced, or may require a high level of complexity during manufacture.

Summary of the Invention

[0004] The object of the present disclosure is to define a sensor array for measuring force or torque that is improved compared to the prior art. In particular, a sensor array should be defined that can be configured to be relatively small, robust, inexpensive, or have high measurement accuracy. In addition, it is intended to define a method for manufacturing the sensor array.

[0005] This object is achieved by a sensor array for measuring force or torque according to claim 1 and a method of use according to the corresponding claim.

[0006] According to one aspect, a sensor array for measuring force or torque, in particular a sensor array for measuring force and torque, is defined. The sensor array comprises a plurality of sensor parts each having a sensor, and the plurality of sensor parts are arranged around a first axis. The sensor array has a plurality of connecting pieces each connecting two adjacent sensor parts to each other, and the connection between the connecting piece and the first sensor part of the adjacent sensor parts is provided in a first axis region, and the connecting piece extends into a second axis region different from the first axis region in a gap between the adjacent sensor parts.

[0007] According to another aspect, a method for manufacturing a sensor array according to the embodiments described herein is defined. The method includes providing a plurality of sensor parts connected by connecting pieces, and the sensor parts are arranged in one plane. The method includes winding the sensor parts and arranging the sensor parts around a first axis.

[0008] According to an exemplary embodiment, the sensor array comprises a plurality of sensor parts each having a sensor. Each sensor part typically comprises a measuring body for receiving or transmitting force or torque. Typically, the sensors of the sensor parts are arranged in or on each measuring body such that the measurement of the sensors is suitable for determining the force or torque acting on the sensor array. Typically, the sensors are flat or planar, in particular arranged flat on the measuring body.

[0009] In a typical embodiment, the sensor of the sensor unit is a measuring element, particularly an expansion measuring element. Each expansion measuring element is typically configured to determine the expansion or mechanical strain of each sensor unit, particularly the measuring body of the sensor unit. The expansion measuring element can include, for example, a film strain gauge (strain gauge) or a semiconductor strain gauge. In particular, the semiconductor strain gauge can be a silicon strain gauge (Si strain gauge). For example, the Si strain gauge can have a particularly small physical size. The sensor of the sensor unit can include at least one expansion measuring element, particularly exactly one expansion measuring element, or exactly two expansion measuring elements. The sensor is typically firmly connected to each sensor unit, particularly each measuring body, for example, by adhesion, soldering, or bonding with glass solder.

[0010] Typically, the sensor units are at least substantially similar in form, particularly at least substantially mechanically similar in form. It should be understood that "at least substantially mechanically similar" particularly means that the mechanical characteristics and shape of the sensor units are at least substantially similar. However, the sensor units may have differences, for example, in the electrical interconnection of the sensors, for example, in the number of conductor tracks running through the sensor units. In this document, a plurality of sensor units may also be referred to as a plurality of basic cells. The force or torque to be determined using the sensor array can be determined based on a plurality of measured values of the sensors of each sensor unit or basic cell.

[0011] In a typical embodiment, the sensor units are arranged around a first axis. The terms "axially", "radially", and "circumferentially" in this document typically relate to the first axis. Typically, at least three sensor units are arranged around the first axis, particularly at least four, or at least five, or at most twenty-four, particularly at most twenty or at most sixteen. In a typical embodiment, the sensor units are arranged around the entire circumference of the first axis. For example, three sensor units may be arranged around the entire circumference of the first axis, particularly in a tripod shape. In a further example, six, eight, or twelve sensor units may be arranged around the entire circumference of the first axis. For example, a sensor array having six sensor units may be arranged in a hexagonal structure, particularly a six-legged structure. In a further embodiment, the sensor units may be arranged around the first axis in a screw-like or helical arrangement, or in a honeycomb structure. In particular, a sensor array having a honeycomb structure can comprise a large number of sensor units, particularly more than twenty sensor units.

[0012] In a typical embodiment, the sensor array comprises a plurality of connecting pieces. Typically, each connecting piece connects two adjacent sensor units among the plurality of sensor units to each other. Typically, each connecting piece is arranged in the gap between two adjacent sensor units. In an embodiment, the connecting piece mechanically connects the sensor units to each other in series. In particular, each pair of two adjacent sensor units in a series is typically connected to each other by a connecting piece. In a typical embodiment, the sensor units connected in series comprise a starting sensor unit and an ending sensor unit, which are not directly connected to each other by a connecting piece. In an embodiment, the sensor units connected by a connecting piece are arranged wound around the first axis.

[0013] According to a typical embodiment, the connecting piece is thinner than the sensor unit. Typically, the thickness of each connecting piece is at most half of the thickness of the sensor unit, for example, at most one-third or at most one-fifth of the thickness of the sensor unit. Typically, the thickness means the radial thickness.

[0014] In a typical embodiment, the sensor array comprises a flexible printed circuit board. The flexible printed circuit board typically comprises a connection piece region forming connection pieces of the sensor array. In an embodiment, the flexible printed circuit board comprises a sensor part region, and each of the sensor parts of the sensor array comprises one of the sensor part regions of the flexible printed circuit board. Typically, each sensor part region of the flexible printed circuit board is in the form of a part of the sensor part. Typically, each sensor part region is firmly connected to the measuring body of the sensor part. For example, the sensor part region of the flexible printed circuit board may be adhered to the measuring body or soldered to a sensor firmly connected to the measuring body. Typically, the measuring body has a greater thickness than the flexible printed circuit board, especially in the radial direction. For example, the measuring body may have a thickness at least twice that of the flexible printed circuit board, especially at least three times or at least five times that of the flexible printed circuit board. In a typical embodiment, the flexible printed circuit board is a flexible conductor, especially a foil-based flexible conductor. The flexible printed circuit board can have one or more layers of foil or conductor tracks. For example, the flexible printed circuit board can have two conductor layers. The thickness of the flexible printed circuit board may be less than 0.5 mm, especially less than 0.3 mm or less than 0.2 mm, for example about 0.1 mm.

[0015] Typically, each sensor part region of the flexible printed circuit board has a wiring region for wiring the sensors of the sensor part respectively. The wiring region of the sensor part region can have, for example, conductor tracks or contact pads for electrically connecting to the sensors of the sensor part. Typically, each connection piece has conductor tracks for electrically connecting a plurality of sensor parts. In a typical embodiment, the sensor part region and the connection pieces are formed by exactly one flexible printed circuit board, especially such that exactly one flexible printed circuit board interconnects all the sensor parts of the sensor array.

[0016] In a typical embodiment, the connection is provided in a first axial region extending in a first axial direction between the connection piece and a first sensor part of two adjacent sensor parts. The connection between the connection piece and the first sensor part can be formed, for example, by a transition between a sensor part region of a flexible printed circuit board arranged on the measuring body of the first sensor part and a connection piece arranged in a gap between adjacent sensor parts. Typically, the connection piece extends in a second axial region different from the first axial region in a gap between adjacent sensor parts. Typically, in the first axial region, another connection is provided between the connection piece and a second sensor part of the adjacent sensor part. In a further embodiment, that another connection may be provided in another axial region different from the first axial region. The another connection between the connection piece and the second sensor part is typically in a similar form to the connection between the connection piece and the first sensor part. In a typical embodiment, the length of the connection piece towards the second axial region can advantageously lengthen the path of the force flow between adjacent sensor parts, and in particular, can lead to enhancing the flexibility of the connection piece.

[0017] According to a typical embodiment, the axial length of the second axial region is greater than the axial length of the first axial region. In an embodiment, the axial length of the second axial region is greater than the length of the connection piece in a direction perpendicular to the first axis. In a typical embodiment, each of the connection pieces extends axially over at least 1 / 4, in particular at least 1 / 3, of the axial length of the sensor part. In a typical embodiment, each connection piece in the second axial region extends axially over at least 1 / 4 of the axial length of the sensor part. In an embodiment, the connection and the another connection between the connection piece and the adjacent sensor part are arranged at the axial end of the sensor part region of the flexible printed circuit board closer to the sensor of the sensor part. In a further embodiment, the connection and the another connection are arranged at the axial end of the sensor part region of the flexible printed circuit board farther from the sensor of the sensor part.

[0018] In an embodiment, each connection piece has a first longitudinal portion extending in the axial direction and a second longitudinal portion extending in the axial direction. Typically, the first longitudinal portion and the second longitudinal portion are arranged in the same axial region, particularly in the second axial region. Typically, the first longitudinal portion and the second longitudinal portion of the connection piece each have a first end and a second end. In an embodiment, each of the first ends is connected to one of the adjacent sensor portions. For example, the first end of the first longitudinal portion may be connected to the first sensor portion of the adjacent sensor portion, and the first end of the second longitudinal portion may be connected to the second sensor portion of the adjacent sensor portion. Typically, the second ends of the first longitudinal portion and the second longitudinal portion are connected to each other by a deflection portion of the connection piece. The deflection portion can provide a deflection of at least 90°, particularly at least 120°, or at least 150°. In a typical embodiment, the deflection portion provides a deflection of at least substantially 180°. In particular, the connection piece may be substantially U-shaped, and the first longitudinal portion and the second longitudinal portion form the legs of the U-shape. In an embodiment, the deflection portion can be in the form of, for example, an arcuate portion of the connection piece, particularly in the form of an arcuate portion between the second ends of the first and second longitudinal portions. In particular, the deflection portion may be in the form of an arcuate shape of 180°, for example, within a U-shaped connection piece. In a further embodiment, the connection piece can have a different shape, for example, a V-shape having the first and second longitudinal portions as legs, and the deflection portion may provide a deflection of less than 180°.

[0019] According to a typical embodiment, the connection piece articulately connects each pair of adjacent sensor portions. Typically, the connection piece is flexible. Typically, each connection piece is in the form of a fixed joint having a joint axis parallel to the first axis. The fixed joint may be in the form of a curved hinge.

[0020] In a typical embodiment, the first longitudinal portion and the second longitudinal portion are twisted. In particular, the orientation of the surface of the twisted longitudinal portion changes from the first end of the longitudinal portion to the second end of the longitudinal portion. The first longitudinal portion and the second longitudinal portion may be twisted so as to face each other in the diametrical direction, particularly along the axial direction. The first longitudinal portion and the second longitudinal portion may also be referred to herein as the first and second twisted regions of the connecting piece. In an embodiment, the flexibility of the connecting piece over the length of the longitudinal portion can be advantageously adjusted. Further, the connecting piece described herein can provide "elasticity" or flexibility in the radial direction, and in particular, can facilitate the assembly of the sensor array.

[0021] Typically, the sensor portion is much stiffer than the connecting piece. For example, as a result of winding the sensor portion and the connecting piece according to the embodiment described herein, when the sensor portions are arranged around the first axis, the adjacent sensor portions will typically be arranged at an angle to each other. The connecting piece typically provides a connection by means of the angle between adjacent sensor portions. In contrast to a connecting piece that extends only in the circumferential direction and is bent through that angle, the connecting piece according to the embodiment described herein can provide a higher level of flexibility. In particular, the connection by means of the angle between adjacent sensor portions can be provided substantially by the twist of the first and second longitudinal portions. For example, the first twisted region and the second twisted region can each provide an angular change of approximately half of the angle between adjacent sensor portions. The connection of the connecting piece to the sensor portion or the deflection portion typically experiences only a small bending load around the joining axis of the connecting piece in the form of a fixed joint. Typically, the deflection portion of the connecting piece is substantially untwisted.

[0022] The embodiments described in this book can have the advantage of increased flexibility in the connection between adjacent sensor units. In particular, the sensor units can be arranged around the first axis with a smaller radius of curvature. For example, the outer diameter of the sensor array measured perpendicular to the first axis can be reduced. Additionally, or alternatively, the improved flexibility can provide improved mobility of the sensor units when assembling the sensor array around the first axis, or can provide a reduction in mechanical effects on the sensors.

[0023] In a typical embodiment, the sensor array comprises an electrical supply line. The electrical supply line typically comprises conductor tracks for operating the sensors of the sensor array, in particular for supplying power or for exchanging data between the sensors. The electrical supply line typically extends partially outside the axial region of the sensor unit. In an embodiment, the electrical supply line is arranged circumferentially between two adjacent sensor units. According to a typical embodiment, the electrical supply line is arranged in one of the connection pieces, typically in exactly one of the connection pieces. In particular, the electrical supply line may be electrically directly connected to the conductor track running within the connection piece in which the electrical supply line is arranged. For example, in an embodiment where the connection piece and the electrical supply line are in the form of a flexible printed circuit board region, the conductor tracks of the flexible printed circuit board run continuously from the electrical supply line into the connection piece, in particular over the sensor unit region. Typically, the electrical supply line runs substantially axially, in particular within the axial region of the sensor unit. In a typical embodiment, the electrical supply line is in the form of part of the flexible printed circuit board of the sensor array, in particular in the form of part of the flexible printed circuit board forming the connection piece and the sensor unit region.

[0024] In an embodiment, the electrical supply line is arranged at a deflection part of one of the connection pieces, for example, at the arcuate part of the connection piece. In particular, the electrical supply line and the deflection part may be arranged substantially in a Y-shape, where the electrical supply line corresponds to the lower branch of the Y, and the two upper branches of the Y correspond to the deflection parts, for example, 180° arcuate deflection parts. In an embodiment, the arrangement at the deflection part can have the advantage that the flexibility of the connection piece on which the electrical supply line is arranged is not impaired by the electrical supply line. In particular, in a typical embodiment, the deflection part is not bent or twisted, and thus the flexibility resulting from the twist of the first and second longitudinal parts remains unaffected.

[0025] In a typical sensor array, the connection pieces mechanically connect the sensor parts in series according to the embodiments described herein. Typically, the electrical supply line is provided on a connection piece arranged in the middle of a series, in particular, between the start sensor part and the end sensor part that are not directly connected by the connection piece, on a connection piece arranged in the middle of a series. The connection piece arranged in the middle is understood to mean the middle connection piece of a series when the number of sensor parts is even. When the number of sensor parts is odd, the electrical supply line may be provided on one of the two connection pieces arranged in the middle of a series. By arranging the electrical supply line in the middle, in particular, the number of conductor tracks in each individual connection piece can be reduced. For example, the conductor track to the sensor part located on the start sensor part side can be wired through the first longitudinal part of the connection piece arranged in the middle, and the conductor track to the sensor part located on the end sensor part side can be wired through the second longitudinal part of the connection piece arranged in the middle. For example, the number of conductor tracks passing through each individual connection piece can be halved. By reducing the number of conductor tracks in the connection piece, the connection piece becomes more flexible. Furthermore, when the number of conductor tracks decreases, the connection piece can be made thinner, and in particular, the flexibility of the connection piece can be further enhanced.

[0026] In a further embodiment, the electrical supply line may be arranged on another connection piece. In yet another embodiment, the electrical supply line may be arranged on the start sensor part or the end sensor part. In particular, the electrical supply line can have a connection piece for the supply line for connecting the electrical supply line to the start sensor part or the end sensor part. The connection piece for the supply line can have a deflection part and one or two longitudinal parts, like the connection pieces described in this document. For example, the connection piece for the supply line may be substantially U-shaped. The connection piece for the supply line may be arranged in the gap between the start sensor part and the end sensor part. The connection piece for the supply line can provide a higher level of flexibility of the electrical supply line, for example, to reduce the mechanical influence on the start sensor part or the end sensor part.

[0027] In a typical embodiment, the sensor array comprises two covers, in particular a first cover and a second cover, and each sensor part is at least partially arranged axially between the first cover and the second cover. The covers can be, for example, in the form of a disk, in particular in the form of a disk arranged coaxially with the first axis. The disk can be, for example, substantially circular. In a typical embodiment, the cover or the measuring body of the sensor part may be made of metal, for example.

[0028] Typically, one of the covers, in particular, has a recess for a supply line for axially routing the electrical supply line. Typically, the recess for the supply line is provided on the radially outer surface of the cover, for example, as a slot or groove. In a further embodiment, the recess for the supply line may be in the form of an axial opening or a through-opening of the cover. In an exemplary embodiment, the recess for the supply line is provided between two sensor portions adjacent in the circumferential direction in the cover. The electrical supply line is typically arranged within the recess for the supply line and, in particular, is arranged axially through the recess for the supply line. The arrangement of the electrical supply line and the recess for the supply line between adjacent sensor portions in the circumferential direction has the advantage, in particular in embodiments where the cover has a further opening or recess for receiving the protrusion of the sensor portion, that the cover is not weakened in the region of the sensor portion by the recess for the supply line. In particular, the robustness of the sensor array can be enhanced. Or the bending of the electrical supply line can be avoided as compared to a version without a recess for the electrical supply line. Further, the embodiment can have the advantage that the electrical supply line and the recess for the supply line are arranged away from the weld seam between the protrusion and the cover, in particular facilitating the assembly of the sensor array.

[0029] In an exemplary embodiment, six sensor portions can be arranged hexagonally around a first axis between two covers and, in particular, can form six legs. For example, the sensor array can be used to measure three different force components or three different torque components independently of each other, in particular to measure three different force components and three different torque components.

[0030] According to an exemplary embodiment, each sensor unit includes a measuring body. The measuring body may be, for example, substantially cuboid. In particular, the structure of the wound sensor unit can correspond to a substantially polygon. Typically, the measuring body has the maximum length in the axial direction. Typically, the measuring body includes a fragile region. Typically, the measuring body is tapered in the fragile region, particularly in the sensor region of the sensor unit. The fragile region can have at least one fragile recess, particularly two fragile recesses. The fragile recess may be, for example, in the form of an opening, a hole, or a notch in the measuring body, such as in the form of a circular hole, or in the form of an L-shaped or C-shaped notch. Typically, the measuring body includes a first side facing the first axis. In an exemplary embodiment, at least one fragile recess is provided at least substantially perpendicular through the first side.

[0031] Typically, the measuring body has a bridge in the fragile region that connects parts of the measuring body between the first axial end and the second axial end of the fragile region to each other. In particular, the bridge can run between two fragile recesses. The fragile recesses may be arranged such that the bridge running between the fragile recesses forms an angle with the axial direction, for example, the angle may be at least 30°, particularly at least 35°, or at least 40°, or a maximum of 60°, particularly a maximum of 55°.

[0032] In an embodiment, the bridges of the measuring body or the sensor unit can be arranged inclined with respect to each other. For example, in a sensor array having six sensor units, the bridges of the measuring body can be arranged in a hexagon around the first axis. The bridges can be arranged between two covers such that they are inclined, particularly inclined with respect to each other, particularly forming six legs.

[0033] Typically, the sensor of the sensor unit is arranged in the vulnerable area of the sensor unit, particularly on the bridge of the vulnerable area. In the vulnerable area, in particular, the expansion of the measurement body can be accurately measured by the sensor. In an embodiment, the measurement body typically comprises a substantially rigid receiving area for receiving the sensor unit area of the flexible printed circuit board. The receiving area may be provided in an axially offset state from the vulnerable area. Typically, the wiring area of the sensor unit area of the flexible printed circuit board is arranged on the receiving area of the measurement body. Typically, the connection piece extends within at least substantially the same axial area as the receiving area of the measurement body.

[0034] In a typical embodiment, the sensor unit comprises a sensor supply line, particularly a sensor supply line for the electrical connection between the sensor and the sensor unit area of the flexible printed circuit board. In an embodiment, the sensor supply line can be provided by a bonding wire between the sensor and the sensor unit area. For example, the bonding wire can be electrically connected to the connection pad of the sensor unit area. In a further embodiment, the sensor supply line can be in the form of a sensor supply line area of the flexible printed circuit board. For example, the sensor supply line area can be connected to the sensor by one or more solder points. The sensor supply line area can be in the form of a connection piece for the sensor supply line having a plurality of arcs or in a meandering shape, particularly to provide a high level of flexibility or low mechanical action between the sensor unit area and the sensor of the flexible printed circuit board.

[0035] In a typical embodiment, each sensor unit, particularly the measuring body of the sensor unit, comprises at least one protrusion at the axial end of each sensor unit. Typically, each sensor unit comprises two insertion parts, particularly one protrusion at each of the two axial ends of the sensor unit. Typically, the protrusion is configured to engage with the first cover or the second cover of the sensor array. The first cover or the second cover can have corresponding openings or recesses for receiving the protrusions of the sensor unit. A strong connection between the protrusion and the cover can be provided, for example, by a plug connection between the protrusion and the cover, or by welding between the protrusion and the cover, particularly by both the plug connection and welding.

[0036] In a typical embodiment, the sensor array has a diameter perpendicular to the first axis of 15 mm or less, particularly 10 mm or less, or 8 mm or less. For example, the sensor array can have a diameter of about 8 mm or about 6 mm. The diameter means the outer diameter. In other embodiments, the sensor array has a diameter perpendicular to the first axis of 21 mm or 32 mm or less. The embodiments described in this document provide, for example, an improvement in the flexibility of the connection piece, or an improvement in the robustness of the connection between the cover and the sensor unit, particularly the miniaturization of the sensor array described in this document for force or torque measurement. In a typical embodiment, the axial length of the sensor array is less than 20 mm, particularly less than 15 mm, particularly without considering the axial length of the electrical supply line.

[0037] According to an exemplary embodiment, a method for manufacturing a sensor array, in particular a sensor array according to the embodiments described herein, is defined. The method includes providing a plurality of sensor portions connected by connection pieces. Typically, the sensor portions are arranged in one plane, in particular in a plane parallel to a first axis. Typically, the providing of the sensor portions and the connection pieces includes providing a measuring body according to the embodiments described herein, in particular having sensors each arranged on or in the measuring body. According to the embodiments described herein, a flexible printed circuit board having a sensor portion region and connection pieces arranged between the sensor portion regions can be provided. The flexible printed circuit board can be arranged in a plane. The measuring body can be firmly connected to each sensor portion region of the flexible printed circuit board. The sensors can be electrically connected to their respective sensor portion regions. By arranging the sensor portions parallel in one plane, for example, these manufacturing steps can be carried out at low cost.

[0038] Typically, the method includes winding the sensor portions and arranging the sensor portions around a first axis. When winding the sensor portions, the sensor portions can be arranged at an angle to each other, in particular, the connection pieces function as fixed joints between adjacent sensor portions. Typically, the connection pieces are not twisted before winding. Typically, the connection pieces, in particular, the first longitudinal portion and the second longitudinal portion of each connection piece, are twisted during winding.

[0039] In a typical embodiment, the method includes connecting the sensor part to at least one cover, in particular a first cover and a second cover. In particular, the sensor part and the at least one cover can be firmly connected to each other. The at least one cover can be provided according to the embodiments described herein. In an embodiment, the sensor part, in particular the wound sensor part, is arranged axially between the first cover and the second cover. The sensor part can have protrusions at each of the axial ends of the sensor part. The protrusions can engage with the openings or recesses of the first cover and the second cover. Additionally, or alternatively, the sensor part and the at least one cover can be materially joined, in particular, they can be adhered or welded to each other. The electrical supply line can be arranged in a recess for the electrical supply line in the first cover or the second cover.

[0040] Compared with the prior art, a typical sensor arrangement can bring the advantage of being able to manufacture a sensor arrangement with a smaller outer diameter. In particular, the flexibility of the connection piece can be improved, and as a result, for example, the circumferential radius of curvature between the sensor parts can be reduced. A typical sensor arrangement can reduce the mechanical influence on the strain gauge sensor system, especially as a result of the twist in the twisted region of the connection piece. The internal stress in the flexible printed circuit board that affects the measurement accuracy of the sensor arrangement can be reduced. In particular, when the flexibility of the connection piece is low, additional interference forces that can combine with the sensor part to which the sensor is attached can be avoided. The embodiment can improve the drift behavior, in particular, avoid or reduce non-linear or non-reproducible temperature responses. Furthermore, the embodiment can bring the advantage of providing a large mobility of the sensor part during assembly. A typical embodiment can further improve signal rejection. In particular, the electrical supply line according to the embodiment can be harmless to the robustness of the connection between the sensor part and the cover. Furthermore, the electrical supply line can have an advantageous effect in terms of the flexibility of the connection piece.

Brief Description of the Drawings

[0041] Further advantages and features of preferred embodiments of the present invention will be described below based on the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0042] Typical embodiments will be described below based on the drawings, but the present invention is not limited to these exemplary embodiments, and the scope of the present invention is determined by the claims.

[0043] In the description of the drawings, the same reference numerals are used for the same or similar parts. In some examples, for the sake of clarity, features already described in connection with other figures will not be described again.

[0044] FIG. 1 shows a schematic diagram of a sensor array 1 according to an exemplary embodiment. The sensor array 1 is in particular in the form of a hexapod having six sensor units 11. The sensor units 11 are mechanically connected in series to each other by connecting pieces 21. The sensor units 11 are arranged over the entire circumference of a first axis 3 and are in particular wound. In FIG. 1, adjacent sensor units 11 in a series are arranged at an angle of 60° to each other. The connecting pieces 21 arranged in the gaps 17 between the sensor units 11 function as a fixed joint between the sensor units 11. A part of the sensor units 11 is arranged axially between a first cover 5 and a second cover 7 and is firmly connected to the first cover 5 and the second cover 7. In particular, projections 65 arranged at each of the axial ends of the sensor units 11 engage corresponding openings in the first cover 5 and the second cover 7. The thickness of the connecting piece 21 in a direction perpendicular to the axis 3, in particular in the radial direction 4, is less than one third of the thickness of the sensor unit 11.

[0045] FIG. 2 shows the sensor unit 11 and the connecting piece 21 in FIG. 1 in an unwound state, in particular excluding the first cover 5 and the second cover 7. Each sensor unit 11 includes a measuring body 55, a sensor 13, and a sensor unit region 53 of a flexible printed circuit board 51, and the sensor unit region 53 is firmly connected to the measuring body 55. The measuring body 55 has two projections 65. The measuring body 55 of the sensor unit 11 includes a fragile region 59, and within the fragile region 59, fragile recesses 61 (two holes passing through the measuring body 55 in FIG. 1) are arranged around a bridge 62 of the measuring body 55. In FIGS. 1, 2, and 4, a sensor 13, which is an SI (International System of Units) strain gauge, is permanently arranged on the bridge 62. Further, the measuring body 55 includes a relatively firm receiving region 57 axially adjacent to the fragile region 59, and this is firmly connected to the sensor unit region 53 of the flexible printed circuit board 51. The sensor 13 and the sensor unit region 53 are electrically connected by a sensor supply line 63 of a bonding wire shown in FIG. 1.

[0046] The flexible printed circuit board 51 further includes connection pieces 21 and an electrical supply line 41 for operating the sensor array 1, particularly the sensor 13. Each connection piece 21 is connected to two adjacent sensor portions 11. A plurality of sensor portions 11 mechanically connected in series include a starting sensor portion 15 and an end sensor portion 16, which are not directly connected to each other by the connection pieces 21. Each connection piece 21 has a connection portion 33 to the first sensor portion of two adjacent sensor portions and another connection portion 35 to the second sensor portion of the adjacent sensor portions. In an embodiment having the flexible printed circuit board 51, the connection portion 33 and the other connection portion 35 are each formed at the axial end of the sensor portion region 53, particularly on the side close to the sensor 13, by the transition from the sensor portion region 53 by the flexible printed circuit board 51 to the connection piece 21. The connection portion 33 and, particularly, the other connection portion 35 are also provided in the first axial region 23. Each connection piece 21 extends within the gap 17 between two adjacent sensor portions 11 beyond the first axial region 23 into a second axial region 25 different from the first axial region 23. The axial length 37 of the connection piece 21 is greater than one-third of the axial length of the sensor portion 11.

[0047] Each connection piece 21 includes a first longitudinal portion 27 and a second longitudinal portion 29 that extend within the same axial region, particularly within the second axial region 25. In the unrolled state of FIG. 2, the first and second longitudinal portions are arranged flatly and axially. The first longitudinal portion 27 of the connection piece 21 and the second longitudinal portion 29 of the connection piece 21 are connected to each other by a deflection portion 31 of the connection piece 21, particularly by an arc-shaped deflection portion 31 of 180°. As a whole, the connection piece 21 is substantially U-shaped.

[0048] FIG. 3 shows a perspective view of the flexible printed circuit board 51 of FIG. 1, particularly as viewed in the direction from the first cover 5 to the second cover 7. In particular, FIG. 3 shows two sensor section regions 53 of the flexible printed circuit board 51, and the two sensor section regions 53 are arranged at an angle 71 of 60° to each other. The two sensor section regions 53 are connected to each other by a connecting piece 21, and the first longitudinal portion 27 and the second longitudinal portion 29 of the connecting piece 21 are twisted. The deflecting portion 31 is not substantially twisted and is not bent. As schematically shown in FIG. 3, a line 77 along the surface of the longitudinal portion at the transition to the deflecting portion 31 forms an angle 75 with the extension line 73 of the sensor section region 53, and each of the angles 75 is about 30°. In particular, the 60° angle 71 between the two sensor sections is provided by a twist of exactly 30° in the exactly opposite direction between the first longitudinal portion 27 and the second longitudinal portion 29. The connecting piece 21 has a high level of flexibility, a small bending load, and a small influence on the sensor system.

[0049] As shown in FIGS. 1 and 2, the flexible printed circuit board 51 includes an electrical supply line 41, and the electrical supply line 41 is provided to a connecting piece 21 arranged at the center among a series of sensor sections 11, and is particularly in a Y shape and is provided to the deflecting portion 31 of the connecting piece 21. By arranging it at the center, the number of conductor tracks per connecting piece can be reduced as compared with the case where the supply line is arranged at the end. The reduction in the number of conductor tracks improves the flexibility of the connecting piece. In FIG. 1, the first cover 5 further has a supply line recess 9 for axially wiring the electrical supply line 41 to the connecting piece 21. The electrical supply line 41 and the supply line recess 9 are arranged in the circumferential direction 6 between the two sensor sections. In particular, the supply line recesses are arranged in the circumferential direction 6 in a manner offset from the recesses of the first cover 5 for the protrusions 65 of the sensor sections 11, and as a result, in particular, the robustness of the first cover 5 is improved.

[0050] FIG. 4 shows a plurality of sensor portions 11 and connection pieces 21 in a non-wound state for a sensor array according to a further embodiment. In FIG. 4, a connection portion 33 and another connection portion 35 between the connection piece 21 and the sensor portion 11 are respectively provided at axial end portions of a sensor portion region 53 on a side farther from the sensor 13. Further, the power supply line 41 is disposed at an end portion, particularly at a sensor portion end 16. The power supply line 41 includes a U-shaped connection piece for the power supply line similar to the connection piece 21. Further, FIG. 4 shows two connection pads 64 for connection to the sensor 13 by, for example, bonding wires (sensor supply lines 63) in each sensor portion region 53. In other embodiments, for example, three, four, or five contact pads may be present.

[0051] FIG. 5 shows a plurality of sensor portions 11 and connection pieces 21 in a non-wound state for a sensor array according to yet another embodiment. The sensor supply line 63 in FIG. 5 is in the form of a part of a flexible printed circuit board 51. In particular, each sensor portion 11 includes a sensor supply line 63 in the form of a meandering connection piece for the sensor supply line between a sensor portion region 53 of the sensor portion 11 and a sensor (hidden by the sensor supply line 63 in FIGS. 5 and 6). For example, the sensors in FIGS. 5 and 6 are film strain gauges. The electrical connection between the sensor supply line 63 and the sensor is provided by solder joints 67. Similar to FIG. 4, the power supply line 41 is disposed at an end portion.

[0052] FIG. 6 shows a plurality of sensor portions 11 and connection pieces 21 in a non-wound state for a sensor array according to a further embodiment. Each sensor portion 11 in FIG. 6 has two fragile recesses 61 that are substantially inclined around a bridge 62 and notched in a C shape. The axial length 37 of the connection piece 21 in FIG. 5 is, for example, about one-third of the axial length of the sensor portion 11. Similar to FIG. 2, the power supply line 41 is disposed at the central connection piece 21 among a series of sensor portions 11.

[0053] FIG. 7 shows a flowchart of a method 100 for manufacturing the sensor array 1 according to the embodiment described in this document. In block 110, the method 100 includes providing a plurality of sensor portions 11 connected by connection pieces 21, and the sensor portions 11 are arranged in one plane. In block 120, the method 100 includes winding the sensor portions 11 and arranging the sensor portions 11 around the first axis 3. In block 130, the method 100 includes connecting the sensor portions 11 to the first cover 5 and the second cover 7. The high flexibility of the connection piece means that it can improve the manufacture of the sensor array and, in particular, the winding of the sensor portions. For example, the embodiment can result in preventing the flexible printed circuit board from peeling off from the measurement body of the sensor portion and reducing the influence exerted by the connection piece on the sensor of the sensor portion.

Claims

1. A sensor array (1) for measuring force and / or torque, comprising: a plurality of sensor units (11), each having a sensor (13) and arranged around a first axis (3); a plurality of connecting pieces (21), each connecting two adjacent said sensor units (11) to each other; a connection (33) between said connecting piece (21) and a first sensor unit among adjacent sensor units is provided in a first axis region (23); said connecting piece (21) extends into a second axis region (25) different from said first axis region (23) within a gap (17) between said adjacent sensor units, the sensor array (1).

2. Each of said connecting pieces (21) has a first longitudinal portion (27) extending in the axial direction and a second longitudinal portion (29) extending in the axial direction; said first longitudinal portion (27) and said second longitudinal portion (29) are arranged in the same axis region, the sensor array (1) according to Claim 1.

3. Said first longitudinal portion (27) and said second longitudinal portion (29) are twisted, the sensor array (1) according to Claim 2.

4. Said first longitudinal portion (27) and said second longitudinal portion (29) of said connecting piece (21) each have a first end and a second end; each of said first ends is connected to one of said adjacent sensor units (11), and said second ends are connected to each other by a deflection portion (31) of said connecting piece (21), the sensor array (1) according to Claim 2 or 3.

5. In said first axis region (23), another connection portion (35) is provided between said connecting piece (21) and a second sensor unit among said adjacent sensor units, the sensor array (1) according to any one of the preceding claims.

6. Each of said connecting pieces (21) is in the form of a fixed joint having a joint axis parallel to said first axis (3), the sensor array (1) according to any one of the preceding claims.

7. Each of said connecting pieces (21) extends axially over at least 1 / 4 of the axial length of said sensor unit (11), the sensor array (1) according to any one of the preceding claims.

8. Said sensor array (1) further comprises an electrical supply line (41), said electrical supply line (41) being arranged in one of said connecting pieces (21), the sensor array (1) according to any one of the preceding claims.

9. The sensor array (1) according to claim 8, wherein the electrical supply line (41) is arranged at one deflection part (31) of the connection pieces (21).

10. The connection pieces mechanically connect the sensor parts in series, The sensor array (1) according to claim 8 or claim 9, wherein the electrical supply line (41) is provided at the connection piece arranged in the center of a series.

11. Comprising a flexible printed circuit board (51) having a sensor part region (53) and a connection piece region, Each of the sensor parts (11) comprises one of the sensor part regions (53) of the flexible printed circuit board (51), The sensor array (1) according to any one of the preceding claims, wherein the connection pieces (21) are provided in the connection piece region of the flexible printed circuit board (51).

12. Further comprising a first cover (5) and a second cover (7), and a part of each of the sensor parts (11) is axially arranged between the first cover (5) and the second cover (7). The sensor array (1) according to any one of the preceding claims.

13. The plurality of sensor parts (11) are arranged around the entire circumference of the first axis (3). The sensor array (1) according to any one of the preceding claims.

14. The sensor array (1) according to any one of the preceding claims, having a diameter of 15 millimeters or less in a direction perpendicular to the first axis (3).

15. Providing the plurality of sensor parts (11) connected by the connection pieces (21) and arranged in one plane, and A method (100) of manufacturing the sensor array (1) according to one of the preceding claims, including winding the sensor parts (11) to arrange the sensor parts (11) around the first axis (3).

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