Joint angle detection device

Abstract

To provide a joint angle detection apparatus that can detect a joint angle.SOLUTION: A joint angle detection apparatus includes a stretchable device that is attached to a joint in a bent state and generates a crease when the joint becomes straight, and a control device that detects the angle of the joint. The stretchable device includes a resin plate which has multiple body parts and multiple hinge parts that connect the body parts with each other while meandering, and a strain gauge which detects a strain amount of the hinge part. There are two strain gauges in the thickness direction perpendicular to the plate shape. The control device stores joint angle information about the shape of the corresponding crease in advance for each angle of the joint, specifies the shape of the crease of the stretchable device from the bending amount of the multiple hinge parts, and calculates the angle of the joint corresponding to the specified shape of the crease on the basis of the joint angle information.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a joint angle detection device.

Background Art

[0002] A stretchable device is excellent in stretchability and flexibility. Such a stretchable device has a resin base material on which an array layer is laminated. The resin base material has a body portion arranged in a matrix shape and a hinge portion connecting the body portions. The hinge portion of Patent Document 1 has a plurality of arc portions and has a meandering shape. When a tensile load acts on the stretchable device, the arc portions of the hinge portion are deformed so as to expand. As a result, the body portions are separated from each other, and the stretchable device is elongated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, it has been studied to provide a strain gauge to the hinge portion of a stretchable device to detect the amount of strain of the hinge portion. Further, development of a joint angle detection device that can detect the angle of a joint such as a finger using this stretchable device has been desired.

[0005] An object of the present invention is to provide a joint angle detection device that can detect a joint angle.

Means for Solving the Problems

[0006] A stretchable device according to one aspect of the present disclosure comprises a stretchable device formed in the shape of a plate, attached to a bent joint, and which generates wrinkles in at least a portion of the stretchable device when the joint is straightened, and a control device that receives an output signal from the stretchable device and detects the angle of the joint. The stretchable device comprises a resin plate having a plurality of body parts spaced apart from each other and a plurality of hinge parts that meander and connect the body parts, and strain gauges arranged on the hinge parts for detecting the amount of strain in the hinge parts. Two strain gauges are provided in the thickness direction perpendicular to the plate shape. The control device stores joint angle information relating to the shape of the wrinkles corresponding to each angle of the joint. The shape of the wrinkles on the stretchable device is identified from the bending amounts of the plurality of hinge parts. Based on the joint angle information, the angle of the joint corresponding to the identified wrinkle shape is calculated. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic perspective view of a stretchable device according to an embodiment. [Figure 2] Figure 2 is a schematic diagram showing a cross-section of the stretchable device according to the embodiment, and more specifically, it is a cross-sectional view taken along the line II-II in Figure 3. [Figure 3] Figure 3 is an enlarged view of a portion of the resin substrate and the first resin plate as seen from the surface of the stretchable device according to the embodiment. [Figure 4] Figure 4 is an enlarged view of the first hinge of the embodiment. [Figure 5] Figure 5 is an enlarged view of the vertical hinge portion of the embodiment when a load is applied that causes it to stretch in the first direction. [Figure 6] Figure 6 is a cross-sectional view of the vertical hinge portion in an embodiment, and more specifically, a cross-sectional view taken along the line VI-VI in Figure 4. [Figure 7] Figure 7 is a cross-sectional view of the vertical hinge portion of the embodiment, showing the case when a load is applied that causes it to stretch in the first direction. [Figure 8] Figure 8 is a cross-sectional view of the vertical hinge portion of the embodiment when a bending load is applied. [Figure 9] Figure 9 is a cross-sectional view of the portion of the array layer that is laminated to the body in this embodiment. [Figure 10] Figure 10 is a circuit diagram showing the circuit configuration of the stretchable device according to the embodiment. [Figure 11] Figure 11 is a flowchart illustrating the process for creating joint angle information. [Figure 12] Figure 12 shows a state in which a stretchable device is attached to the fingers and the joint angle is gradually reduced. [Figure 13] Figure 13 is a schematic diagram showing a magnified view of the stretchable device shown in Figure 12. [Figure 14] Figure 14 is a flowchart showing the processing steps of the control device when using the joint angle detection device of the embodiment. [Modes for carrying out the invention]

[0008] Embodiments for implementing this disclosure will be described in detail with reference to the drawings. The invention of this disclosure is not limited by the contents described in the following embodiments. Furthermore, the components described below include those that can be easily conceived by a person skilled in the art, and those that are substantially the same. Moreover, the components described below can be combined as appropriate. It should be noted that the disclosure is merely an example, and any modifications that can be easily conceived by a person skilled in the art while maintaining the spirit of the invention are naturally included within the scope of the present invention. In order to make the explanation clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in this specification and each drawing, components similar to those described above with respect to previously shown drawings are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0009] Furthermore, in this specification and the claims, when describing a manner in which one structure is placed on top of another structure, unless otherwise specified, the term "on top of" includes both cases: when one structure is placed directly on top of another structure so as to be in contact with it, and when another structure is placed above another structure via yet another structure.

[0010] Figure 1 is a schematic perspective view of a stretchable device according to an embodiment. As shown in Figure 1, the joint angle detection device 100 comprises a stretchable device 1 and a control device 110. The joint angle detection device 100 is a device for detecting the joint angles of the fingers 200 (see Figure 12). Although the joint angle detection device 100 of this embodiment detects the joint angles of the fingers 200, this disclosure may also provide a joint angle detection device that detects the angles of other joints such as the knee, elbow, and wrist.

[0011] The stretchable device 1 is formed in a plate shape. The stretchable device 1 has a surface 1a and a back surface 1b (not shown in Figure 1; see Figure 2) facing opposite directions. Hereinafter, the direction parallel to each of the surface 1a and back surface 1b will be referred to as the planar direction. One direction parallel to the planar direction will be referred to as the first direction Dx. The direction parallel to the planar direction and intersecting the first direction Dx will be referred to as the second direction Dy. The direction normal to surface 1a (stacking direction) will be referred to as the third direction Dz. In addition, viewing the stretchable device 1 from the third direction Dz may be referred to as the planar view.

[0012] The stretchable device 1 is formed in a rectangular (quadrilateral) shape in plan view. Therefore, the surface 1a has a pair of short sides 1c and a pair of long sides 1d. The first direction Dx is parallel to the long sides 1d. The second direction Dy is parallel to the short sides 1c. Therefore, in this embodiment, the first direction Dx and the second direction Dy are orthogonal to each other. Hereinafter, one of the ends of the stretchable device in the first direction Dx will be referred to as the first end 1e and the other end as the other end 1f.

[0013] In a plan view, the stretchable device 1 is divided into a detection region 2 capable of detecting a load input to the stretchable device 1 and a frame-shaped peripheral region 3 surrounding the outside of the detection region 2. In FIG. 1, a boundary line L1 is drawn to facilitate understanding of the boundary between the detection region 2 and the peripheral region 3.

[0014] FIG. 2 is a diagram schematically showing a cross-section of the stretchable device according to the embodiment, and more specifically, is a cross-sectional view taken along line II-II in FIG. 3. As shown in FIG. 2, the stretchable device 1 includes a first resin plate 60 having a back surface 1b, a second resin plate 70 having a front surface 1a, and a resin base material 10 and an array layer 30 sandwiched between the first resin plate 60 and the second resin plate 70. The first resin plate 60 and the second resin plate 70 cooperate with each other to form a housing for accommodating the resin base material 10 and the array layer 30. The first resin plate 60 has a laminated surface 60a that is the opposite surface of the back surface 1b. The resin base material 10 and the array layer 30 are laminated in this order on the laminated surface 60a.

[0015] The first resin plate 60 and the second resin plate 70 are made of polyimide and are excellent in stretchability and flexibility. The resin materials forming the first resin plate 60 and the second resin plate 70 are not limited to polyimide, and may be acrylic resin, epoxy resin, urethane resin, etc., and the present disclosure is not limited to the above. Also, in the following description, the upper side or the upper direction is one direction of the third direction Dz, and refers to the side where the second resin plate 70 is arranged when viewed from the first resin plate 60. Also, the lower side or the lower direction is the other direction of the third direction Dz, and refers to the side where the first resin plate 60 is arranged when viewed from the second resin plate 70.

[0016] FIG. 3 is an enlarged view of a part of the resin base material and the first resin plate seen from the surface side of the stretchable device according to the embodiment. In FIG. 3, the resin base material 10 is hatched for easy viewing. The resin base material 10 is provided on the laminated surface 60a of the first resin plate 60. The resin base material 10 has stretchability, flexibility, and insulation properties. The resin base material 10 is formed from a resin material such as polyimide, for example.

[0017] The resin base material 10 has a plurality of body portions 11 and a plurality of hinge portions 12 that extend in a planar direction while meandering. When viewed in plan, the body portion 11 and the hinge portion 12 are each disposed in the detection region 2.

[0018] The body portion 11 is rectangular (square) in plan view. The four corner portions of the body portion 11 are arranged so as to point in the first direction Dx and the second direction Dy. The plurality of body portions 11 are arranged in the first direction Dx and the second direction Dy and are spaced apart from each other. The array layer 30 laminated on the body portion 11 includes a switch element (transistor 36) (see FIG. 9). Note that the present disclosure is not limited to a rectangular shape of the body portion 11 in plan view, and may be a circular shape or other polygonal shapes.

[0019] The hinge portion 12 connects adjacent body portions 11. There are two types of hinge portions 12: a vertical hinge portion 12A that extends in the first direction Dx and a horizontal hinge portion 12B that extends in the second direction Dy.

[0020] Further, a portion of the resin base material 10 where the body portion 11 and the hinge portion 12 are not provided is a cutout portion 19 that penetrates the resin base material 10 in the third direction Dz. That is, the resin base material 10 has a plurality of cutout portions 19. The array layer 30 is not laminated in the region overlapping the cutout portion 19. As shown in FIG. 2, the cutout portion 19 is filled with the second resin plate 70. For this reason, the stretchable device 1 has low rigidity in the range overlapping the cutout portion 19 and has stretchability and flexibility (stretchable property). When a load acts on the stretchable device 1, the hinge portion 12 is deformed. On the other hand, the deformation of the body portion 11 is small, and damage to the functional element (transistor 36 in the present embodiment) laminated on the body portion 11 is suppressed.

[0021] In this embodiment, the cutout portion 19 is filled with the second resin plate 70, but in this disclosure, it may be filled with the first resin plate 60. Alternatively, the cutout portion 19 may be filled with the first resin plate 60 and the second resin plate 70. Alternatively, the cutout portion 19 may be filled with a resin material other than the first resin plate 60 and the second resin plate 70. Furthermore, the cutout portion 19 may be empty and nothing may be placed in it.

[0022] Next, the details of the hinge portion 12 will be explained. Note that rotating the vertical hinge portion 12A by 90° results in the same shape as the horizontal hinge portion 12B. Therefore, the vertical hinge portion 12A will be explained as a representative example, and the explanation of the horizontal hinge portion 12B will be omitted.

[0023] Figure 4 is an enlarged view of the first hinge of the embodiment. Figure 5 is an enlarged view of the vertical hinge portion of the embodiment when a load is applied that causes it to stretch in the first direction. Note that the imaginary line K shown in Figures 4 and 5 is an imaginary line that passes through the center of the width direction of the vertical hinge portion 12A.

[0024] As shown in Figure 4, the width W of the vertical hinge portion 12A is constant in the length direction over which the vertical hinge portion 12A extends. The vertical hinge portion 12A has two base portions 13 located at both ends in the length direction of the vertical hinge portion 12A, and four bent portions 14 positioned between the two base portions 13. Therefore, the vertical hinge portion 12A extends in the first direction Dx while meandering between the two body portions 11. For the sake of explanation, the body portion 11 connected to one end of the vertical hinge portion 12A will be referred to as the first body portion 11a, and the body portion 11 connected to the other end of the vertical hinge portion 12A will be referred to as the second body portion 11b.

[0025] The base portion 13 is continuous with the body portion 11 and extends linearly from the body portion 11 in the first direction Dx. Of the two base portions 13, the base portion 13 continuous with the first body portion 11a is referred to as the first base portion 13a, and the base portion 13 continuous with the second body portion 11b is referred to as the second base portion 13b.

[0026] The bent portion 14 is bent in the second direction Dy. The bent portion 14 in this embodiment is arc-shaped. However, the bent portion of this disclosure may be formed in an angular shape instead of an arc shape. The four bent portions 14 are the first arc portion 21, the second arc portion 22, the third arc portion 23, and the fourth arc portion 24, which are arranged in order from the first base portion 13a toward the second base portion 13b. The first arc portion 21 and the fourth arc portion 24 are quarter-circular and bent at 90 degrees. The second arc portion 22 and the third arc portion 23 are semi-circular and bent at 180 degrees.

[0027] One end of the first arc portion 21 is connected to the first base portion 13a. The first arc portion 21 is bent in one direction of the second direction Dy relative to the first base portion 13a. Also, one end of the fourth arc portion 24 is connected to the second base portion 13b. The fourth arc portion 24 is bent from the second base portion 13b in the other direction of the second direction Dy. Therefore, the first arc portion 21 and the fourth arc portion 24 bend in opposite directions.

[0028] One end of the second arc section 22 is connected to the first arc section 21. The other end of the second arc section 22 points in the other direction of the second direction Dy. The third arc section 23 has one end connected to the fourth arc section 24, and the other end points in one direction of the second direction Dy and is connected to the other end of the second arc section 22. Thus, the vertical hinge section 12A meanders due to the four bent sections 14.

[0029] As shown in Figure 4, each bend 14 is divided into an inner circumferential portion located on the inside (inner circumference side) and an outer circumferential portion located on the outside (outer circumference side), with the imaginary line K as the boundary. In Figure 4, the inner and outer circumferential portions of each bend 14 are enclosed by ellipses to clearly show their respective boundaries. However, everything on the inner circumference side of the imaginary line K is the inner circumference, and everything on the outer circumference side of the imaginary line K is the outer circumference. Therefore, the area enclosed by the ellipse is either the inner circumference or a part of the outer circumference.

[0030] As shown in Figure 5, when the stretchable device 1 is pulled in the first direction Dx (see arrow A1 in Figure 5), the vertical hinge portion 12A stretches in the first direction Dx. In other words, the bending angle of each bent portion 14 increases, and the length of the vertical hinge portion 12A in the first direction Dx increases. Furthermore, when the bending angle of each bent portion 14 increases, the following loads (stresses) act on the inner and outer circumferences of each bent portion 14.

[0031] A tensile load acts on the first inner circumference 21N of the first arc portion 21. A compressive load acts on the first outer circumference 21G of the first arc portion 21. A tensile load acts on the second inner circumference 22N of the second arc portion 22. A compressive load acts on the second outer circumference 22G of the second arc portion 22. A tensile load acts on the third inner circumference 23N of the third arc portion 23. A compressive load acts on the third outer circumference 23G of the third arc portion 23. A tensile load acts on the fourth inner circumference 24N of the fourth arc portion 24. A compressive load acts on the fourth outer circumference 24G of the fourth arc portion 24.

[0032] From the above, when the vertical hinge portion 12A is stretched in the first direction Dx, a tensile load acts on the inner circumference of each bent portion 14. On the other hand, a compressive load acts on the outer circumference of each bent portion 14. In addition, regarding the magnitude of the stress acting on the vertical hinge portion 12A, the stress (tensile load or compressive load) increases as you move from the center of the hinge portion 12 in the width direction towards the ends in the width direction. Next, the array layer 30 will be described. The array layer 30 will be described by dividing it into the portion located in the hinge portion 12 (vertical hinge portion 12A, horizontal hinge portion 12B), the portion located in the body portion 11, and the portion of the array layer 30 located in the peripheral region 3.

[0033] Figure 6 is a cross-sectional view of the vertical hinge portion in an embodiment, and more specifically, a cross-sectional view taken along the line VI-VI in Figure 4. Figure 7 is a cross-sectional view of the vertical hinge portion of the embodiment when a load that stretches in the first direction Dx is applied. As shown in Figure 6, the portion of the array layer 30 located in the vertical hinge portion 12A has a plurality of first insulating layers 31, second insulating layer 32, third insulating layer 33, fourth insulating layer 34, and fifth insulating layer 35 that are stacked in order in the third direction Dz. Each insulating layer is made of highly flexible polyimide. As a result, the vertical hinge portion 12A is easily deformed.

[0034] Furthermore, the voltage supply line 40 is laminated on the second insulating layer 32. The first signal line 41 and the second signal line 42 are laminated on the third insulating layer 33. As shown in Figure 3, the voltage supply line 40, the first signal line 41, and the second signal line 42 each extend in the first direction Dx along the vertical hinge portion 12A. In addition, the voltage supply line 40, the first signal line 41, and the second signal line 42 each span across multiple vertical hinge portions 12A and multiple body portions 11. As a result, the voltage supply line 40, the first signal line 41, and the second signal line 42 each extend in the first direction Dx within the detection region 2.

[0035] Furthermore, the end of the voltage supply line 40 extends into the peripheral region 3 and is connected to the common electrode 105 (see Figure 1). The end of the first signal line 41 extends into the peripheral region 3 and is connected to the first signal line selection circuit 103 (see Figure 1). The end of the second signal line 42 extends into the peripheral region 3 and is connected to the second signal line selection circuit 104 (see Figure 1).

[0036] Furthermore, as shown in Figure 6, the voltage supply line 40, the first signal line 41, and the second signal line 42 are each located in the center of the vertical hinge section 12A in the width direction. Therefore, the stress acting on the voltage supply line 40, the first signal line 41, and the second signal line 42 is small.

[0037] Furthermore, a strain gauge 27 is provided in the portion of the array layer 30 located in the vertical hinge portion 12A. The strain gauge 27 deforms in accordance with the deformation of the hinge portion 12, and its resistance value changes. The strain gauge 27 has a first strain gauge 28 laminated on the first insulating layer 31 and a second strain gauge 29 laminated on the fifth insulating layer 35. The first strain gauge 28 is located on the lower side (closer to the back surface 1b), and the second strain gauge 29 is located on the upper side (closer to the front surface 1a).

[0038] The first strain gauge 28 and the second strain gauge 29 overlap in the third direction Dz. That is, as shown in Figure 4, when viewed from above, the first strain gauge 28 and the second strain gauge 29 overlap. The first strain gauge 28 and the second strain gauge 29 extend from the first body portion 11a to the second body portion 11b. The first strain gauge 28 and the second strain gauge 29 are positioned so as to overlap only with the inner circumference portions (first inner circumference portion 21N, second inner circumference portion 22N, third inner circumference portion 23N, fourth inner circumference portion 24N) at each bend portion 14.

[0039] From the above, when the hinge portion 12 is stretched in the first direction Dx (see arrow A1 in Figures 5 and 7), a common stress (tensile load) acts on the first strain gauge 28 and the second strain gauge 29 in the portions that overlap with each bent portion 14. Also, as shown in Figure 7, although the first strain gauge 28 and the second strain gauge 29 are separated in the third direction Dz, the amount they extend in the first direction Dx is the same (see arrows A2 and A3). Therefore, the amount of strain generated in the first strain gauge 28 and the second strain gauge 29 is also the same.

[0040] Next, we will explain the case when a bending load is applied to the stretchable device 1. For the sake of explanation, the portion of the array layer 30 laminated on the first body portion 11a will be referred to as the first array portion 30A, the portion laminated on the second body portion 11b will be referred to as the second array portion 30B, and the portion laminated on the vertical hinge portion 12A will be referred to as the hinge array portion 30C.

[0041] Figure 8 is a cross-sectional view of the vertical hinge portion of the embodiment when a bending load is applied. As shown in Figure 8, when a bending load B centered on a virtual line P (see Figure 1) extending in the second direction Dy is applied to the stretchable device 1, the stretchable device 1 bends, and the stretchable device 1 becomes arc-shaped in cross-section. In detail, the central part of the hinge array portion 30C in the first direction Dx protrudes upward, and deforms into an arc shape in cross-sectional view (side view). In addition, the first array portion 30A and the second array portion 30B are displaced relatively downward relative to the hinge array portion 30C.

[0042] When such a bending load B is applied, the first resin plate 60 receives a compressive load in the first direction Dx. The second resin plate 70 receives a tensile load in the first direction Dx. Therefore, in the hinge array section 30C, the layer located closer to the first resin plate 60 receives a compressive load in the first direction Dx (see arrow B1 in Figure 8). Also, the layer located closer to the second resin plate 70 receives a tensile load in the first direction Dx (see arrow B2 in Figure 8). As a result, a compressive load is applied to the first strain gauge 28 and a tensile load is applied to the second strain gauge 29. Therefore, when a bending load B is applied, the direction of the strain generated in the first strain gauge 28 and the second strain gauge 29 is different. In other words, because the resistance values ​​of the first strain gauge 28 and the second strain gauge 29 are different, the bending load B can be detected.

[0043] Next, the lateral hinge portion 12B will be described. Although not specifically shown in the figures, the portion of the array layer 30 located in the lateral hinge portion 12B has multiple insulating layers and a gate wire 43. Also, as shown in Figure 4, the gate wire 43 is arranged across multiple lateral hinge portions 12B and multiple body portions 11. As a result, the gate wire 43 extends in the second direction Dy within the detection region 2. Furthermore, the end of the gate wire 43 extends into the peripheral region 3 and is connected to the gate wire drive circuit 102.

[0044] Figure 9 is a cross-sectional view of the portion of the array layer that is laminated on the body in an embodiment. The portion of the array layer 30 that is laminated on the body portion 11 has a first insulating layer 44, a second insulating layer 45, a third insulating layer 46, a fourth insulating layer 47, and a fifth insulating layer 48 that are laminated in order above the body portion 11. The first insulating layer 44, the second insulating layer 45, the third insulating layer 46, the fourth insulating layer 47, and the fifth insulating layer 48 are, for example, silicon oxide films. In addition, the gate insulating film 36b of the transistor 36 is interposed between the first insulating layer 44 and the second insulating layer 45.

[0045] The portion of the array layer 30 stacked on the body portion 11 has a transistor 36. The transistor 36 comprises a semiconductor layer 36a, a gate insulating film 36b, a gate electrode 36c, a drain electrode 36d, and a source electrode 36e. The semiconductor layer 36a is connected to the drain electrode 36d and the source electrode 36e via a contact layer.

[0046] The gate electrode 36c is connected to the gate wire 43 via a contact layer. The drain electrode 36d is connected to the voltage supply line 40. The source electrode 36e is connected to one end of the first strain gauge 28 and one end of the second strain gauge 29 via a contact layer.

[0047] As shown in Figure 1, the portion of the array layer 30 located in the peripheral region 3 includes a connection section 101, a gate line drive circuit 102, a first signal line selection circuit 103, a second signal line selection circuit 104, and a common electrode 105.

[0048] The connection portion 101 is for connecting to a drive IC (Integrated Circuit) located outside the stretchable device 1. In this embodiment, the control device 110 has the function of the drive IC, and the connection portion 101 is connected to the control device 110. The drive IC may be mounted as COF (Chip On Film) on a flexible printed circuit board or a rigid circuit board (not shown). Alternatively, the drive IC may be mounted as COG (Chip On Glass) in the peripheral region 3 of the first resin plate 60.

[0049] The gate line drive circuit 102 is a circuit that drives multiple gate lines 43 based on various control signals from the control device 110. The gate line drive circuit 102 sequentially or simultaneously selects multiple gate lines 43 and supplies gate drive signals to the selected gate lines 43.

[0050] The first signal line selection circuit 103 is a switch circuit that sequentially or simultaneously selects the first signal lines 41. Based on the selection signal supplied from the control device 110, the first signal line selection circuit 103 connects the selected first signal line 41 to the control device 110, and the signal from the first signal line 41 is sent to the control device 110.

[0051] The second signal line selection circuit 104 is a switch circuit that sequentially or simultaneously selects the second signal line 42. Based on the selection signal supplied from the drive IC, the second signal line selection circuit 104 connects the selected second signal line 42 to the control device 110, and the signal from the second signal line 42 is sent to the control device 110.

[0052] The common electrode 105 is wiring for supplying voltage to the voltage supply line 40 and extends along the peripheral region 3. The common electrode 105 is connected to the control device 110 via the connection part 101 and a predetermined voltage is applied to it.

[0053] Figure 10 is a circuit diagram showing the circuit configuration of the stretchable device according to the embodiment. As shown in Figure 10, when a gate drive signal is sent to the gate line 43, the transistor 36 turns ON. Then, a predetermined amount of current flows simultaneously from the voltage supply line 40 to the first strain gauge 28 and the second strain gauge 29. In addition, a signal (current amount) corresponding to the resistance value of the first strain gauge 28 is sent to the first signal line 41. In addition, a signal (current amount) corresponding to the resistance value of the second strain gauge 29 is sent to the second signal line 42. The detection result (current amount) is then sent to the control device 110 via the first signal line 41 and the second signal line 42.

[0054] The stretchable device 1 has been described above. When the stretchable device 1 is attached to the object being inspected, wrinkles 300 will form on at least a part of the stretchable device 1 (see Figure 13). Further details will be described later. Next, the control device 110 will be described.

[0055] The control device 110 is a so-called computer, and is equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and storage devices such as a hard disk drive (HDD). The CPU reads and executes programs stored in RAM and outputs the calculation results to the storage devices. RAM is the main memory that can record and read programs and data. ROM stores programs such as the BIOS (Basic Input Output System).

[0056] Furthermore, the control device 110 stores joint angle information. This joint angle information is information regarding the shape of the wrinkle 300 (see Figure 13) corresponding to each joint angle. The joint angle information is obtained in advance through testing. The following describes the creation process (testing process) for obtaining the joint angle information. The part targeted in this embodiment is the second joint 201 of the finger 200.

[0057] Figure 11 is a flowchart illustrating the process of creating joint angle information. Figure 12 shows a state in which a stretchable device is attached to the fingers and the joint angle is gradually reduced. Figure 13 is a schematic diagram showing a magnified view of the stretchable device in Figure 12.

[0058] As shown in Figure 11, step S1 of the joint angle information creation process is the process of bending the fingers 200 and attaching the stretchable device 1 to the joint. More specifically, as shown in Figure 12, the fingers 200 are bent to their most bent state. As a result, the bending angle of the second joint 201 of the fingers 200 becomes approximately 90 degrees. Then, the stretchable device 1 is attached to the outside of this second joint 201. The method of attaching the stretchable device 1 can be a fastener or double-sided tape, but is not particularly limited in this disclosure.

[0059] Furthermore, in order to enable the stretchable device 1 to detect bending load (see arrow B in Figure 8), it is attached so that the longitudinal direction of the finger 200 coincides with the first direction Dx of the stretchable device 1. Also, the shape of the stretchable device 1 is such that it follows the shape of the second joint 201, as shown in step S1 of Figure 13.

[0060] Next, step S2 of the joint angle information creation process is the process of straightening the fingers 200 and changing the shape of the stretchable device 1. Specifically, first, as shown in step S21 of Figure 12, the bending angle of the fingers 200 is gradually reduced, and finally, as shown in step S22 of Figure 12, the fingers 200 are straightened.

[0061] According to this, as shown in Figure 13, in the state of step S21, the amount of deflection of the entire stretchable device 1 is reduced. Also, a compressive load is applied to the stretchable device 1 in the first direction Dx, and wrinkles 300 are generated in a part of the stretchable device 1. The wrinkles 300 have a shape in which multiple convex portions 301 protruding in one direction of the third direction Dz and convex portions 301 protruding in the other direction of the third direction Dz are arranged alternately in the first direction Dx.

[0062] Furthermore, according to the state in step S22, the bending angle of the second joint 201 becomes 0°, and the bending of the stretchable device 1 is eliminated. Also, the tip 302 of the protrusion 301 that constitutes the wrinkle 300 in step S22 has a sharper shape than the tip 302 of the wrinkle 300 in step S21. In other words, a large bending load is acting on the vertical hinge portion 12A located at the tip 302.

[0063] In addition, in step S2 of the joint angle information creation process, the control device 110 receives the output signal (current value) of the entire process in which the shape of the stretchable device 1 changes. Also in step S2, the second joint 201 of the finger 200 is imaged using an imaging device (not shown).

[0064] In step S3 of the joint angle information creation process, the control device 110 calculates the resistance values ​​of the first strain gauge 28 and the second strain gauge 29 from the output values ​​of the stretchable device 1, and calculates the amount of strain of the first strain gauge 28 and the second strain gauge 29, in other words, the amount of bending of the vertical hinge portion 12A. Then, it identifies the overall shape of the wrinkle 300 generated in the stretchable device 1 from the amount of bending of the vertical hinge portion 12A. In addition, the control device 110 receives output signals for the entire process in which the shape of the stretchable device 1 changes. Therefore, the control device 110 identifies the overall shape of the wrinkle 300 for the entire process.

[0065] Next, in step S4 of the joint angle information creation process, the data captured by the imaging device is analyzed to detect changes in the angle of the second joint 201. Then, the detected change in the angle of the second joint 201 is associated with the change in the overall shape of the wrinkle 300 obtained in step S3 to create joint angle information. Although the method for detecting changes in the angle of the second joint 201 has been described using imaging and analysis, this disclosure is not limited to this. Changes in the angle of the second joint 201 may also be identified by visual inspection, and this is not particularly limited.

[0066] Next, the method of using the joint angle detection device 100 of the embodiment will be described. To use it, first, the fingers 200 are bent and the stretchable device 1 is attached to the outside of the second joint 201 (see step S1 in Figure 12). Next, the bending angle of the second joint 201 is changed (see step S2 or step S3 in Figure 12). As a result, a compressive load is applied to the stretchable device 1, and wrinkles 300 are generated on a part of the stretchable device 1. Then, the control device 110 receives the detection result of the stretchable device 1 and performs the following processing steps to detect the angle of the second joint 201.

[0067] Figure 14 is a flowchart showing the processing steps of the control device when using the joint angle detection device of the embodiment. In step S31, the control device 110 calculates the resistance values ​​of the first strain gauge 28 and the second strain gauge 29 from the detection results of the stretchable device 1 and detects the amount of strain of the first strain gauge 28 and the second strain gauge 29. Furthermore, it calculates the amount of bending of the vertical hinge portion 12A from the amount of strain of the first strain gauge 28 and the second strain gauge 29 and identifies the overall shape of the wrinkle 300.

[0068] Next, in step S32, the control device 110 calculates the angle of the second joint 201 corresponding to the shape of the identified wrinkle 300 based on the joint angle information. Specifically, in step S32, the control device extracts a shape (wrinkle shape) that matches the overall shape of the identified wrinkle 300 from the joint angle information. Then, it determines the joint angle corresponding to the extracted shape (wrinkle shape) as the detection result (angle of the second joint 201). After the determination, the control device 110 displays the detection result on a display device (not shown) and terminates. From the above, the joint angle detection device 100 of this embodiment can detect the angle of a joint.

[0069] Although embodiments have been described above, this disclosure is not limited to the examples described above. For example, regarding information on the shape of a wrinkle included in the joint angle information, in the embodiments it is the shape of the entire wrinkle, but in this disclosure it may be a part of the shape of the wrinkle. Also, as a part of the shape of the wrinkle, it may be the shape of the tip 302 of the wrinkle 300 as shown in Figure 13. Details will be described below.

[0070] As shown in steps S21 and S22 of Figure 13, the tip 302 of the wrinkle 300 is arc-shaped. Furthermore, the tip 302 of the convex portion 301 of the wrinkle 300 becomes sharper in step S22 than in step S21, and the curvature of the tip 302 increases. In other words, the curvature of the tip in step S21 is greater than that of the tip in step S21. That is, as the bending angle of the second joint 201 decreases, the curvature of the tip 302 of the convex portion 301 increases. Therefore, the information regarding the shape of the wrinkle included in the joint angle information may be the curvature of the tip 302. With this, in step S31, it is only necessary to specify the shape of the tip 302 of the convex portion 301, rather than the shape of the entire wrinkle 300, making the calculation easier. [Explanation of Symbols]

[0071] 1. Stretchable device 2 Detection area 3. Peripheral area 10 Resin substrate 11 Body 12. Hinge section 12A Vertical hinge section 12B Horizontal hinge section 14. Bending section 19. Weight-reducing section 21 First arc section 22 Second arc section 23 Third arc section 24. Fourth arc section 27 Strain Gauges 28. First strain gauge 29. Second strain gauge 30 array layers 36 transistors 40 Voltage supply lines 41. First signal line 42 Second signal line 43 Gate Line 60 First resin plate 70 Second resin plate 100 Joint Angle Detection Device 110 Control device 200 fingers 201 Second joint 300 wrinkles 301 Convex part 302 Tip

Claims

1. A stretchable device formed in a plate shape, attached to a bent joint, and which develops wrinkles in at least a portion of the joint when the joint is straightened, A control device that receives an output signal from the stretchable device and detects the angle of the joint, Equipped with, The stretchable device is A resin plate having multiple body parts spaced apart from each other, and multiple hinge parts that meander and connect the body parts to each other, A strain gauge is placed in the hinge portion to detect the amount of strain in the hinge portion, It has, Two strain gauges are provided in the thickness direction perpendicular to the plate shape. The control device is The joint angle information relating to the shape of the wrinkles corresponding to each joint angle is stored in advance. The shape of the wrinkles in the stretchable device is determined from the bending amounts of the multiple hinge portions. Based on the aforementioned joint angle information, the angle of the joint corresponding to the identified wrinkle shape is calculated. Joint angle detection device.

2. The information relating to the shape of the wrinkle is the overall shape of the wrinkle. The joint angle detection device according to claim 1.

3. The information relating to the shape of the wrinkle is the curvature of the tip of the wrinkle. The joint angle detection device according to claim 1.

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