A bending sensor and a method of use

Abstract

Embodiments of the present application provide a bending sensor and a usage method. The sensor includes a substrate layer, a first conductive layer, and a second conductive layer. The first conductive layer and the second conductive layer are disposed on the substrate layer and are separated from each other. The deformation lengths generated by the first conductive layer and the second conductive layer in the bending area of the bending sensor are different in the bending state, resulting in different resistance change amounts. The bending degree of the object to be measured can be calculated through the two resistance change amounts. By correspondingly setting a plurality of bending areas, it is possible to calculate the bending degree of the object to be measured through multiple observation quantities, improving the measurement accuracy and scene applicability of the bending sensor.

Description

Technical Field

[0001] The embodiments of the present application relate to, but are not limited to, the field of sensors, and in particular to a bending sensor and a method of use. Background Art

[0002] The curvature of an object is generally path-dependent; that is, the curvature of the object changes along its length. Current bend sensors typically measure the object's curvature using a single resistance or voltage value. However, this single observation makes it difficult to detect changes in the central portion of the object's curvature, reducing the sensor's accuracy. Summary of the Invention

[0003] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0004] The embodiments of the present application aim to solve at least one of the technical problems existing in the prior art, and provide a bending sensor.

[0005] According to an embodiment of the first aspect of the present application, a bending sensor includes:

[0006] substrate layer;

[0007] a first conductive layer, the first conductive layer being disposed on the substrate layer;

[0008] a second conductive layer, the second conductive layer being disposed on the substrate layer, the first conductive layer and the second conductive layer being separated;

[0009] The first conductive layer and the second conductive layer of the bending area of the bending sensor have different deformation lengths when bent, thereby causing different resistance changes of the first conductive layer and the second conductive layer of the bending portion of the bending sensor.

[0010] In certain embodiments of the first aspect of the present application, the first conductive layer and the second conductive layer are formed by conductive lines winding in a step-like shape.

[0011] In certain embodiments of the first aspect of the present application, the first conductive layer and the second conductive layer are separated by a dividing characteristic line, the first side of the first conductive layer away from the dividing characteristic line and the second side of the second conductive layer away from the dividing characteristic line are parallel or offset, a first angle between the dividing characteristic line and the first side is greater than 0 degrees and less than 180 degrees, and a second angle between the dividing characteristic line and the second side is greater than 0 degrees and less than 180 degrees.

[0012] In some embodiments of the first aspect of the present application, the deformation lengths of the first conductive layer and the second conductive layer in the non-bending region of the bending sensor are the same in the bending state, so that the resistance change amounts of the first conductive layer and the second conductive layer in the bending portion of the bending sensor are proportional.

[0013] In some embodiments of the first aspect of the present application, resilient layers are provided along the length direction on both sides of the substrate layer, and the first conductive layer and the second conductive layer are located between the resilient layers on both sides.

[0014] In some embodiments of the first aspect of the present application, a first power connection interface is provided at one end of one side of the first conductive layer, and a second power connection interface is provided at the other end of the other side of the first conductive layer.

[0015] In some embodiments of the first aspect of the present application, a third power connection interface is provided at one end of one side of the second conductive layer, and a fourth power connection interface is provided at the other end of the other side of the second conductive layer.

[0016] In some embodiments of the first aspect of the present application, the substrate layer is made of a polymer material.

[0017] In some embodiments of the first aspect of the present application, the first conductive layer and the second conductive layer are made of a metal conductor material.

[0018] In an embodiment of the second aspect of the present application, a method for using a bending sensor is applied to the bending sensor as described above; the method for using includes:

[0019] Attach the bending region of the bending sensor to the object to be measured;

[0020] Apply a current with the same voltage to the first conductive layer and the second conductive layer;

[0021] Detect a first current value of the current passing through the first conductive layer and a second current value of the current passing through the second conductive layer;

[0022] Calculate a first resistance change amount of the first conductive layer according to the first current value, and calculate a second resistance change amount of the second conductive layer according to the second current value;

[0023] Calculate the bending degree of the object to be measured according to the first resistance change amount and the second resistance change amount.

[0024] The above solution has at least the following beneficial effects: By adopting a segmented feature line, the conductor material is segmented into multiple parts such as the first conductive layer and the second conductive layer; when the bending sensor is forced to deform under the action of the object to be measured, the bending degree of the object to be measured can be calculated through the resistance change amounts of multiple parts of the conductor material, that is, multiple observed quantities, improving the measurement accuracy and scene applicability of the bending sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0026] Figure 1 is the structural diagram of the bending sensor;

[0027] Figure 2 This is a structural diagram of a bending sensor, wherein the first conductive layer and the second conductive layer are formed by conductive wires winding in a step-like shape;

[0028] Figure 3 A structural diagram of a first conductive layer and a second conductive layer formed by conductive lines winding in a step-like shape;

[0029] Figure 4 is a schematic cross-sectional view of a first conductive layer and a second conductive layer;

[0030] Figure 5 is a schematic diagram of stretching the first conductive layer;

[0031] Figure 6 is a structural diagram of the bending sensor, where the segmentation characteristic line is a curve;

[0032] Figure 7 This is a step-by-step diagram showing how to use the bend sensor. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0034] It should be noted that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and the like in the specification, claims, or accompanying drawings are used to distinguish similar items and are not necessarily intended to describe a specific sequence or precedence.

[0035] The embodiments of the present application are further described below with reference to the accompanying drawings.

[0036] An embodiment of the present application provides a bending sensor.

[0037] Reference Figure 1 The bending sensor includes: a substrate layer 200 , a first conductive layer 110 and a second conductive layer 120 .

[0038] Among them, the first conductive layer 110 is disposed on the substrate layer 200; the second conductive layer 120 is disposed on the substrate layer 200, and the first conductive layer 110 and the second conductive layer 120 are separated from each other.

[0039] The deformation lengths generated by the first conductive layer 110 and the second conductive layer 120 in the bending zone of the bending sensor in the bending state are different, so that the resistance change amounts of the first conductive layer 110 and the second conductive layer 120 in the bending part of the bending sensor are different.

[0040] Moreover, the deformation lengths generated by the first conductive layer 110 and the second conductive layer 120 in the non-bending zone of the bending sensor in the bending state are the same, so that the resistance change amounts of the first conductive layer 110 and the second conductive layer 120 in the bending part of the bending sensor are proportional.

[0041] For the bending sensor, a conductive layer is formed by bonding a conductive material on the substrate layer 200 to measure the bending degree of the object to be measured. The bending sensor is pasted or fixed on the object to be measured and the substrate layer 200 is made to fit the object to be measured. When the object to be measured is bent, the object to be measured transmits the force to the substrate layer 200 through the pasting part, and the substrate layer 200 then stretches the metal conductor. When the conductive material undergoes tensile deformation, its resistance changes accordingly, and the bending condition of the measured object is estimated by the resistance change amount.

[0042] Refer to Figure 4 , for the conductive layer, the resistance R of the conductor is proportional to its thickness h, length L, and resistivity ρ, and inversely proportional to its cross-sectional area S. The formula of the resistance law is R = ρL / S. Where ρ is the resistivity of the material used to make the resistor, L is the total length of the conductive material wound into the resistor, and S is the cross-sectional area of the copper foil. Among them, S = wh, and R is the resistance value. w is the width of the conductor at the x position.

[0043] The first conductive layer 110 and the second conductive layer 120 are separated by a dividing feature line 300.

[0044] Refer to Figure 6 , in this embodiment, the dividing feature line 300 is a straight line. Of course, in other embodiments, the dividing feature line 300 can be a curve.

[0045] The first side of the first conductive layer 110 away from the dividing feature line 300 and the second side of the second conductive layer 120 away from the dividing feature line 300 are parallel.

[0046] The first included angle between the dividing feature line 300 and the first side is greater than 0 degrees and less than 180 degrees, and the second included angle between the dividing feature line 300 and the second side is greater than 0 degrees and less than 180 degrees.

[0047] When the conductive layer in a bent state is forced to stretch, w is a function of x, and the width of the first conductive layer 110 and the position x satisfy the following relationship: Where x∈[0,L].

[0048] Reference Figure 5 , the strain of the conductive layer at x is ε, and the constrained elongation of the conductive layer is △L, then the resistance change of path A is: The resistance change of path B is:

[0049]

[0050] It can be understood that the deformation of the conductive layer per unit cross-sectional height under unit load is the strain of the conductive layer.

[0051] Due to the positional relationship between the segmentation characteristic line 300 and the first conductive layer 110 and the second conductive layer 120, when the bending sensor is forced to bend, its length changes differently at different positions. The portion that does not bend can be considered to have a strain ε=0, and the portion that changes can be considered to have ε=Cε. The resistance change of section A is significantly smaller than the resistance change of section B, which facilitates more accurate calculation of the bending degree.

[0052] If the bending of the object being measured is not constant, it is necessary to first assume the bending deformation law, such as the linear law ε = bx + c. It can be seen that when b = 0, it expresses a common circular curve.

[0053] According to the constraints, when the two resistances change by ΔR A and ΔR B When changes occur, the A and ΔR B b and c can be estimated to obtain the degree of curvature of the object to be measured.

[0054] Of course, in other embodiments, the bending deformation rule can be set according to the specific scenario; for example, for a cantilever beam, the bending deformation rule is set to ε=bx 2 +cx.

[0055] Specifically, in other embodiments, the dividing feature line 300 is not limited to a straight line, and dividing feature lines 300 of other shapes can also be designed, as long as the first angle between the dividing feature line 300 and the first side is greater than 0 degrees and less than 180 degrees, and the second angle between the dividing feature line 300 and the second side is greater than 0 degrees and less than 180 degrees. When the dividing feature line 300 is a curve, each point of the dividing feature line 300 satisfies the following conditions: the first angle between the tangent line corresponding to the point of the dividing feature line 300 and the tangent line of the point corresponding to the first side in the width direction is greater than 0 degrees and less than 180 degrees, and the second angle between the tangent line corresponding to the point of the dividing feature line 300 and the tangent line of the point corresponding to the second side in the width direction is greater than 0 degrees and less than 180 degrees.

[0056] For another example, the strain is set to ε = ax 3 + bx 2 + cx + d, and different dividing feature lines 300 can be set on the bending sensor to increase the observed quantities, and the four variables a, b, c, and d can be solved.

[0057] In some embodiments of the present application, a first power-on interface 111 is provided at one end of one side of the first conductive layer 110, and a second power-on interface 112 is provided at the other end of the other side of the first conductive layer 110. For example, the first power-on interface 111 is connected to the positive pole of the power supply, and the second power-on interface 112 is connected to the negative pole of the power supply, and then the first conductive layer 110 is powered on. Of course, it can also be that the second power-on interface 112 is connected to the positive pole of the power supply, and the first power-on interface 111 is connected to the negative pole of the power supply.

[0058] In some embodiments of the present application, a third power-on interface 121 is provided at one end of one side of the second conductive layer 120, and a fourth power-on interface 122 is provided at the other end of the other side of the second conductive layer 120. For example, the third power-on interface 121 is connected to the positive pole of the power supply, and the fourth power-on interface 122 is connected to the negative pole of the power supply, and then the second conductive layer 120 is powered on. Of course, it can also be that the fourth power-on interface 122 is connected to the positive pole of the power supply, and the third power-on interface 121 is connected to the negative pole of the power supply.

[0059] In some embodiments of the present application, the first conductive layer 110 can be made into upper and lower layers, separated by a very thin and easily extensible insulating medium in the middle, and the first power-on interface 111 of the upper layer is connected to the first power-on interface 111 of the lower layer through a via hole, so that the first conductive layer 110 of the upper layer is connected in series with the first conductive layer 110 of the lower layer, the first power-on interface 112 of the upper layer is connected to the positive pole of the power supply, and the second power-on interface 112 of the lower layer is connected to the negative pole of the power supply, and then the first conductive layer 110 is powered on.

[0060] In some embodiments of the present application, the first conductive layer 110 and the second conductive layer 120 can form a half-bridge circuit, thereby reducing the sensitivity to environmental noises such as temperature and humidity.

[0061] The first conductive layer 110 and the second conductive layer 120 are made of metal conductor materials. Since metal conductor materials such as copper generally exhibit obvious yield when the strain is 1%, they are prone to yield when the measured object is deformed too much. Yield means that the conductor material has undergone plastic deformation. After the metal conductor material is extended, if there is no external force to restore it, it will maintain its original shape and lose its elasticity. When the force is removed, the sensor cannot return to its original state, which is disadvantageous for a bending sensor.

[0062] Therefore, by bonding the first conductive layer 110, the second conductive layer 120 and the substrate layer 200 with an adhesive, and then stretching the first conductive layer 110 and the second conductive layer 120 through the substrate layer 200 to generate strain. In this way, the substrate layer 200 is generally made of polymer materials such as PVC. Compared with metal conductor materials, the elastic modulus of polymer materials is generally not high, but polymer materials have a larger elastic range, and the strain at which yield occurs is much higher than that of metal conductor materials. When the force on the substrate layer 200 is removed, the conductive layers of the bending sensor can return to a straight state under the restoring force of the substrate layer 200.

[0063] In addition, rebound layers 400 are provided along the length direction on both sides of the substrate layer 200, and the first conductive layer 110 and the second conductive layer 120 are located between the rebound layers 400 on both sides. The rebound layers 400 can help the first conductive layer 110 and the second conductive layer 120 return to a straight state faster.

[0064] Refer to Figure 2 and Figure 3 , in some embodiments of the present application, the first conductive layer 110 and the second conductive layer 120 are formed by winding a wire into a stepped shape. The first conductive layer 110 and the second conductive layer 120 can be formed by etching a copper foil to etch the copper foil into a winding stepped shape. By arranging and manufacturing in this way, as long as the etched copper foil is laminated with PI to form an FPC and then pasted on the substrate, measurement can be achieved. Due to the use of winding wires, not only can the resistance value be well increased, but the signal-to-noise ratio can also be effectively reduced. Double-layer or multi-layer FPCs can also be used, and the length of the conductive wire can be increased through vias, thereby improving the observation sensitivity.

[0065] In another aspect of the embodiments of the present application, a method for using a bending sensor is provided, which is applied to the bending sensor as described above.

[0066] Refer to Figure 7 , the method for using a bending sensor includes:

[0067] Step S100: Attach the bending area of the bending sensor to the object to be measured;

[0068] Step S200: Apply currents with the same voltage to the first conductive layer and the second conductive layer;

[0069] Step S300: Detect the first current value of the current passing through the first conductive layer and the second current value of the current passing through the second conductive layer;

[0070] Step S400: Calculate the first resistance change amount of the first conductive layer based on the first current value, and calculate the second resistance change amount of the second conductive layer based on the second current value;

[0071] Step S500: Calculate the bending degree of the object to be measured based on the first resistance change amount and the second resistance change amount.

[0072] It can be understood that multiple bending areas can be set, and each bending area can be provided with dividing feature lines as needed, so that the bending sensor can have multiple observation quantities.

[0073] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that: without departing from the principles and purposes of the present application, these embodiments can be subject to various changes, modifications, substitutions, and variations. The scope of the present application is defined by the embodiments and their equivalents.

[0074] The above has specifically described the preferred embodiments of the present application, but the present application is not limited to the embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present application, and these equivalent deformations or substitutions are all included within the scope defined by this embodiment.

Claims

1. A bending sensor, characterized in that: include: substrate layer; a first conductive layer, the first conductive layer being disposed on the substrate layer; a second conductive layer, the second conductive layer being disposed on the substrate layer, the first conductive layer and the second conductive layer being separated; The first conductive layer and the second conductive layer of the bending area of the bending sensor have different deformation lengths when bent, thereby causing the first conductive layer and the second conductive layer of the bending area of the bending sensor to have different resistance changes; The resistance change of the first conductive layer is: ; The resistance change of the second conductive layer is: ; is the thickness of the conductive layer, is the total length of the conductive material wound into the conductive layer, w is the width of the conductive layer at position x, is the tensile elongation strain of the conductive layer at position x, and the conductive layer is the first conductive layer or the second conductive layer.

2. The bending sensor according to claim 1, characterized in that: The first conductive layer and the second conductive layer are formed by conducting wires winding in a step-like shape.

3. The bending sensor according to claim 1, characterized in that: The first conductive layer and the second conductive layer are separated by a dividing characteristic line, a first side of the first conductive layer away from the dividing characteristic line and a second side of the second conductive layer away from the dividing characteristic line are parallel, a first angle between the dividing characteristic line and the first side is greater than 0 degrees and less than 180 degrees, and a second angle between the dividing characteristic line and the second side is greater than 0 degrees and less than 180 degrees.

4. The bending sensor according to claim 1, characterized in that: The first and second conductive layers in the non-bending region of the bending sensor have the same deformation length when bent, so that the resistance changes of the first and second conductive layers in the bending portion of the bending sensor are proportional.

5. The bending sensor according to claim 1, characterized in that: Resilient layers are provided on both sides of the substrate layer along the length direction, and the first conductive layer and the second conductive layer are located between the resilient layers on both sides.

6. A bending sensor according to claim 1 or 2, characterized in that: A first power interface is provided at one end of the first conductive layer, and a second power interface is provided at the other end of the first conductive layer.

7. A bending sensor according to claim 1 or 2, characterized in that: A third power interface is provided at one end of the second conductive layer, and a fourth power interface is provided at the other end of the second conductive layer.

8. The bending sensor according to claim 1, characterized in that: The substrate layer is made of polymer material.

9. The bending sensor according to claim 1, characterized in that: The first conductive layer and the second conductive layer are made of metal conductor material.

10. A method for using a bending sensor, characterized in that: Applicable to the bending sensor according to any one of claims 1 to 9; the method of use comprises: Laying the bending area of the bending sensor onto the object to be measured; passing currents of the same voltage through the first conductive layer and the second conductive layer; detecting a first current value of a current passing through the first conductive layer and a second current value of a current passing through the second conductive layer; Calculate a first resistance change of the first conductive layer according to the first current value, and calculate a second resistance change of the second conductive layer according to the second current value; The bending degree of the object to be measured is calculated according to the first resistance change and the second resistance change.

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