Thermal touch FBG (Fiber Bragg Grating) composite perception sensor and bionic manipulator

Abstract

The utility model relates to the technical field of fiber bragg grating sensing, and particularly discloses a touch heat sense FBG composite sensing sensor and a bionic manipulator. The touch heat sense FBG composite perception sensor comprises a flexible packaging body and a force measurement FBG assembly arranged in the flexible packaging body, the force measurement FBG assembly comprises a first force measurement FBG and a second force measurement FBG, and the first force measurement FBG and the second force measurement FBG are both of a cylindrical spiral structure and are coaxially and symmetrically arranged; the bionic manipulator comprises a touch thermal sense FBG composite sensing sensor. According to the utility model, the sensitivity of the sensor for sensing pressure change can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical fiber grating sensing, in particular to a tactile and thermal FBG composite sensing sensor and a bionic manipulator. Background Art

[0002] The tactile and thermal FBG composite sensing sensor uses fiber Bragg Grating (FBG) technology to achieve composite perception of touch and temperature. The working principle of the FBG sensor is based on the reflection of light. When light passes through the FBG, light of a specific wavelength will be reflected, while light of other wavelengths continues to be transmitted. When the FBG is subjected to strain or temperature changes, the central wavelength of its reflected wavelength will change. By measuring these changes, the change in strain or temperature can be determined. In the tactile sensor, the external force acts on the elastic body, causing the FBG to strain, thereby causing the central wavelength to move, realizing the measurement of force. At the same time, the change in temperature will also affect the central wavelength of the FBG.

[0003] In the prior art, the applicant of the present invention disclosed a fiber Bragg grating-based manipulator touch and slip sensor in a patent with publication number CN110779639A, including a sensing layer, a first cascaded grating string and a second cascaded grating string are arranged in the sensing layer, and a temperature compensation grating is arranged outside the sensing layer, which is surface-mounted or buried inside the manipulator finger, and can detect touch and slip information such as positive pressure, shear force, and sliding, and can compensate for the interference of ambient temperature on the measurement information.

[0004] However, during the sensing process, if the temperature fluctuation range is large, the FBG central wavelength drift caused by temperature change may be 1 to 2 orders of magnitude larger than the central wavelength drift caused by strain, which may lead to large strain settlement errors during data decoupling, thereby reducing the sensing accuracy.

[0005] The above technical problems need to be solved. Utility Model Content

[0006] In view of this, the purpose of the utility model is to provide a tactile-thermal FBG composite sensing sensor and a bionic manipulator using the sensor, which can improve the sensitivity of the sensor to sensing pressure changes.

[0007] To achieve the above-mentioned objectives, on the one hand, the utility model provides a tactile-thermal FBG composite sensing sensor, including a flexible package and a force measuring FBG component arranged in the flexible package, the force measuring FBG component including a first force measuring FBG and a second force measuring FBG, the first force measuring FBG and the second force measuring FBG are both cylindrical spiral structures and are coaxially symmetrically arranged.

[0008] As a further improvement to the technical solution of the utility model, the upper surface of the flexible package is a planar structure, and the first force measuring FBG and the second force measuring FBG are arranged parallel to the upper surface of the flexible package.

[0009] As a further improvement to the technical solution of the utility model, both axial ends of the first force measuring FBG and the second force measuring FBG are connected by fixing members.

[0010] As a further improvement to the technical solution of the utility model, a temperature measuring FBG is also buried in the flexible package, the temperature measuring FBG is located below the force measuring FBG component, and a rigid tube is fixedly sleeved outside the gate area of ​​the temperature measuring FBG.

[0011] As a further improvement to the technical solution of the utility model, the temperature measuring FBG and force measuring FBG components are spatially cross-distributed.

[0012] As a further improvement to the technical solution of the utility model, the rigid tube is made of stainless steel.

[0013] As a further improvement to the technical solution of the utility model, the flexible packaging body is a silica gel structure.

[0014] To achieve the above-mentioned purpose, on the other hand, the utility model also provides a bionic manipulator, which applies a plurality of the above-mentioned tactile and thermal FBG composite sensing sensors.

[0015] Compared with the prior art, the utility model has the following beneficial technical effects:

[0016] The utility model provides a tactile and thermal FBG composite sensing sensor, which adopts a force measuring FBG component with a double helix structure. When stress acts on the sensor, strain zones (high strain zone and low strain zone) with different strains can be formed inside the flexible package. The original single-layer FBG only detects pressure changes in a certain stress zone, while the double helix structure can detect pressure changes between the high strain zone and the low strain zone. The data after detection are integrated and combined with the strain transfer effect in the flexible package, the average wavelength drift of the first force measuring FBG and the second force measuring FBG can be obtained, thereby improving the sensitivity of the sensor to sensing pressure changes.

[0017] The bionic manipulator provided by the present invention naturally has the above-mentioned beneficial technical effects because it applies the above-mentioned tactile and thermal FBG composite sensing sensor.

[0018] Advantages of additional aspects of the present invention will be partially given in the following description, and partially become apparent from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model;

[0020] Figure 2 It is a schematic diagram of the strain area of ​​the force measuring FBG component of the utility model;

[0021] Figure 3 This is a first structural diagram of the force measuring FBG assembly of the utility model;

[0022] Figure 4 This is a second structural diagram of the force measuring FBG assembly of the utility model;

[0023] Figure 5 This is the third structural diagram of the force measuring FBG assembly of the present utility model. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention.

[0025] Embodiment 1

[0026] like Figure 1 As shown: This embodiment provides a tactile-thermal FBG composite sensing sensor, including a flexible package 1 and a force measuring FBG component arranged in the flexible package 1.

[0027] The flexible package 1 provides a certain degree of elasticity and protection to prevent the optical fiber Bragg grating from being directly subjected to external impact or damage; preferably, the flexible package 1 is a silicone structure, which has good elasticity and flexibility, and has good resistance to a variety of chemical substances, is easy to form and process, and can be customized in different shapes and sizes as needed to meet specific application requirements.

[0028] FBG (fiber Bragg grating) is the core part of the sensor. It can reflect back specific wavelengths of incident light and transmit other wavelengths of light. When affected by the external environment (such as temperature, pressure, stress, etc.), the reflected wavelength will change. This change can be used to monitor environmental parameters; of course, the fiber Bragg grating also needs to be connected to the external demodulation instrument through the corresponding connecting optical fiber.

[0029] The present embodiment provides a tactile-thermal FBG composite sensing sensor, the main improvement of which is that the force measuring FBG component includes a first force measuring FBG 21 and a second force measuring FBG 22, both of which are cylindrical spiral structures and are coaxially symmetrically arranged.

[0030] By using the force measuring FBG component with the double helix structure, when stress F acts on the sensor, strain zones with different strains (high strain zone 6a and low strain zone 6b) can be formed inside the flexible package 1. The original single-layer FBG only detects pressure changes in a certain stress zone, while the double helix structure can detect pressure changes between the high strain zone and the low strain zone. The data after detection are integrated and combined with the strain transfer effect in the flexible package 1, the average wavelength drift of the first force measuring FBG21 and the second force measuring FBG22 can be obtained, thereby improving the sensitivity of the sensor to sensing pressure changes.

[0031] When in use, the first force measuring FBG21 and the second force measuring FBG22 are respectively connected to an external demodulation instrument to transmit independent data; the first force measuring FBG21 and the second force measuring FBG22 have the same characteristics, and their spiral structure parameters (such as radius, pitch, number of turns, etc.) can be determined according to needs.

[0032] In this embodiment, the upper surface of the flexible package 1 is a planar structure, and the first force measuring FBG21 and the second force measuring FBG22 are arranged parallel to the upper surface of the flexible package 1. The upper surface of the flexible package 1 is a planar structure, which helps to simplify the manufacturing and assembly process of the sensor. When stress acts on the sensor, the design of the planar upper surface may help to distribute the strain more evenly and reduce local stress concentration, thereby improving the durability and reliability of the sensor; the first force measuring FBG21 and the second force measuring FBG22 are arranged parallel to the upper surface of the flexible package 1. This layout helps to maintain the consistency and symmetry between the two FBGs, thereby improving the accuracy and repeatability of the measurement.

[0033] In this embodiment, both axial ends of the first force measuring FBG 21 and the second force measuring FBG 22 are connected by a fixing member 3. The use of the fixing member 3 can ensure that the two FBGs maintain the stability of their relative positions when subjected to force, and can effectively transfer the force acting on the sensor to the FBG to achieve uniform distribution of force.

[0034] In this embodiment, a temperature measuring FBG4 is also embedded in the flexible package 1, and the temperature measuring FBG4 is located below the force measuring FBG component, and a rigid tube 5 is fixedly sleeved outside the grid area of ​​the temperature measuring FBG4. The temperature measuring FBG4 is rigidly packaged, and will produce very small strain due to the slight deformation of the rigid body, reducing the strain interference of the deformation caused by stress on the temperature measuring FBG4. It mainly detects the change of temperature and is used for temperature compensation in the sensor. This compensation mechanism is well known to those skilled in the art and will not be repeated here; combined with the sensing characteristics of different FBGs, the cross-sensitivity problem of touch and heat is preliminarily solved, and the data decoupling problem of force touch and heat fusion perception signals is realized; the sensing structure uses the strain transfer effect of the flexible package 1, combined with the reference grating method and the dual wavelength method, and uses the structural decoupling method to solve the cross-sensitivity problem of strain and temperature; when temperature and stress act on the sensor at the same time, the force measuring FBG component will detect the changes of strain and temperature at the same time, while the temperature measuring FBG4, due to the rigid package, will produce very small strain due to the deformation of the rigid body, which is mainly used to detect temperature changes.

[0035] The rigid tube 5 provides physical protection for the temperature measuring FBG 4, reduces the interference of environmental factors on its measurement results, and improves the stability of temperature measurement; preferably, the rigid tube 5 can be made of stainless steel.

[0036] In this embodiment, the temperature measuring FBG4 and the force measuring FBG component are spatially cross-distributed, that is, the axis of the temperature measuring FBG4 is perpendicular to the axis of the force measuring FBG component; this helps to reduce the crosstalk between the two gratings, so that they maintain sufficient sensitivity and stability.

[0037] Embodiment 2

[0038] This embodiment provides a bionic robot arm, in which a tactile-thermal FBG composite sensing sensor shown in the first embodiment can be directly attached to a robot finger (not shown in the figure) or buried inside the robot finger structure. Since it uses the above-mentioned tactile-thermal FBG composite sensing sensor, it naturally also has the above-mentioned beneficial technical effects.

[0039] The above is only an embodiment of the utility model, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A tactile and thermal FBG composite sensing sensor, comprising a flexible package and a force measuring FBG component disposed in the flexible package, characterized in that: The force-measuring FBG assembly comprises a first force-measuring FBG and a second force-measuring FBG, wherein the first force-measuring FBG and the second force-measuring FBG are both cylindrical spiral structures and are coaxially symmetrically arranged.

2. The tactile-thermal FBG composite sensing sensor according to claim 1, characterized in that: The upper surface of the flexible package is a planar structure, and the first force measuring FBG and the second force measuring FBG are arranged parallel to the upper surface of the flexible package.

3. The tactile-thermal FBG composite sensing sensor according to claim 1, characterized in that: Both axial ends of the first force measuring FBG and the second force measuring FBG are connected by fixing members.

4. The tactile-thermal FBG composite sensing sensor according to claim 1, characterized in that: A temperature measuring FBG is also embedded in the flexible package, the temperature measuring FBG is located below the force measuring FBG component, and a rigid tube is fixedly sleeved outside the gate area of ​​the temperature measuring FBG.

5. The tactile-thermal FBG composite sensing sensor according to claim 4, characterized in that: The temperature measuring FBG and force measuring FBG components are spatially cross-shaped.

6. The tactile-thermal FBG composite sensing sensor according to claim 4, characterized in that: The rigid tube is made of stainless steel.

7. The tactile-thermal FBG composite sensing sensor according to claim 4, characterized in that: The flexible packaging body is a silica gel structure.

8. A bionic manipulator, characterized in that: It comprises the tactile-thermal FBG composite sensing sensor as described in any one of claims 1 to 7.

Images