Intelligent detection and control insole preparation and detection method based on optical fiber sensing and insole thereof

Abstract

The invention discloses an insole preparation and detection method based on intelligent detection and control of an optical fiber sensor and an insole thereof. The insole preparation and detection method comprises the following steps: performing single side polishing treatment on an optical fiber by utilizing a side polishing technology to obtain the optical fiber sensor; a plurality of optical fiber sensors are distributed, arranged and packaged on the front side of an insole body, and a camera shooting fixing module comprising a signal light source and a camera shooting module is arranged and packaged on the back side of the insole body, so that the insole is obtained; the plurality of optical fiber sensors are electrically connected with the camera fixing module; optical fiber polishing and grinding surfaces of the optical fiber sensors are downwards distributed at at least four specific positions of the front surface of the insole; comprising two sole upper ends, a sole center and a heel, by combining image processing and signal coding technologies, a motion state change curve of a wearing user can be detected, collected and displayed in real time, and the intelligent insole is multifunctional, light in weight and low in cost.

Description

Technical Field

[0001] The present invention belongs to the field of optical fiber sensing, flexible electronics and wearable technology, and specifically relates to an insole preparation and detection method based on optical fiber sensing intelligent detection and control and an insole thereof. Background Art

[0002] With the development of science and technology and the progress of the times, people's health awareness continues to improve. According to research and surveys, it is expected that by 2050, the average life expectancy of human beings will increase by 22%. With the growing demand for human health assessment, the development of continuous and dynamic health monitoring systems has become increasingly important. Among them, wearable gait monitoring systems have received widespread attention because they can monitor important health indicators of the human body in real time, such as plantar pressure, number of steps and gait. At the same time, with the increasing popularity of wearable devices in health monitoring, motion analysis, smart home and other scenarios, how to achieve high-precision, low-cost and low-power sensing solutions while ensuring wearing comfort has become a research and development hotspot. Gait monitoring technology plays a vital role in many key areas such as medical diagnosis, disease rehabilitation, fall prevention, sports training, human-computer communication, etc. Among them, optical fiber stands out in the preparation of a new generation of flexible sensors with its excellent ductility, elasticity and robustness. Compared with traditional metal sensors, in terms of external structure, optical fiber has excellent elastic limit and can withstand large bending angles without loss and rebound. At the same time, in some high-frequency vibration environments, optical fiber is less likely to undergo plastic deformation, avoiding the situation where metal sensors heat up and break at the axis.

[0003] The existing technology of the traditional metal strain gauges for sole detection has certain limitations: although the metal wire or film strain gauge is mature and reliable, it is prone to fatigue fracture under long-term bending or high-frequency vibration environment; at the same time, the electrical signal is susceptible to electromagnetic interference during transmission, and the signal-to-noise ratio decreases. In addition to the structure of the sensing point, the wearable gait monitoring of the existing technology also has some defects in the overall framework: it often uses a combination of pressure distribution sensing pads, accelerometers or gyroscopes, which often requires additional external brackets or has high costs and is not suitable for embedding in daily shoes. The advantages of the sole detection sensor made of plastic optical fiber are: the plastic optical fiber (POF) made of polymer materials has excellent flexibility (can withstand hundreds of 90° bends and still recover), low Young's modulus (increases sensitivity to small deformations) and excellent anti-electromagnetic interference characteristics. Use it in the insole to realize the optical detection of sole pressure and gait, without the need for complex shielding or filtering circuits, so as to achieve the effect of small size and comfortable wearing, and has broad market prospects. Summary of the invention

[0004] In view of the deficiencies of the prior art and the evaluation of future market applications, the present invention provides a method for preparing, detecting an insole based on fiber optic sensing for intelligent detection and control, and the insole thereof. The side-polished fiber optic is prepared by using the fiber optic side polishing technology, and the sensing points are reasonably arranged on the insole. Then, the real-time spot signal is obtained by using the spot collection and processing technology, and the signal is processed twice to match and display information such as the motion state of the wearing user. At the same time, communication matching is achieved with the infrared module, and the spot signal of a specific action is encoded and transmitted to achieve the remote control function. It can achieve high-sensitivity plantar pressure detection while ensuring the softness and comfort of the insole; highly integrate the sensor device and the data acquisition system to reduce external wiring and additional devices; at the same time, it can expand the traditional gait monitoring function and increase the specific action coding and infrared remote control capabilities.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A method for preparing an insole based on a fiber optic sensor for intelligent detection and control according to the present invention includes:

[0007] Performing single-side polishing treatment on the optical fiber by using the side polishing technology to obtain an optical fiber sensor;

[0008] Distributing and encapsulating a plurality of the optical fiber sensors on the front surface of the insole body, and encapsulating a camera fixing module including a signal light source and a camera module on the back surface of the insole body to obtain the insole.

[0009] Specifically, the performing single-side polishing treatment on the optical fiber by using the side polishing technology to obtain an optical fiber sensor includes: intercepting a plastic optical fiber with a length of at least 20 cm, wiping an area with a length of at least 1 cm at the center with an alcohol cotton, placing the optical fiber on a polishing machine, and polishing the clean area side of the optical fiber against the polishing wheel of the polishing machine until a D-shaped optical fiber with a specified depth is prepared. Among them, electrical connections are made between the plurality of optical fiber sensors and the camera fixing module. The camera fixing module is provided with a plug-in member that extends outward and has a square cross-section along the rear end of the insole; a jack is provided above the plug-in member for inserting a micro camera; four small-diameter jacks are arranged on the lower side of the plug-in member for inserting the output ends of four optical fiber sensors; there is a flat structure connecting body between the camera fixing module and the plug-in member.

[0010] Further, the distributing and encapsulating a plurality of the optical fiber sensors on the front surface of the insole body includes: arranging the optical fiber polishing surfaces of the plurality of optical fiber sensors downward at at least four specific positions on the front surface of the insole, and the specific positions correspond to four center of gravity points of the sole, including two at the upper end of the sole, one at the center of the sole, and one at the heel.

[0011] The insole body is made of a flexible elastomer material.

[0012] An insole detection method based on optical fiber sensing for intelligent detection and control of the present invention inserts a micro camera probe with a Typ-c interface into the upper jack of the camera fixing module, and the other Typ-C interface of the micro camera is connected to the processor for wired signal transmission; the USB interface of an infrared remote control module is connected to the processor; turn on the signal light source, and the processor runs the spot processing terminal program; build a stepped strain test platform, and set the step depth to 0.5 - 7 mm and the step size to 0.5 mm; to achieve pressure sensing tests including the following contents: gait cycle detection, plantar morphology drawing, motion state analysis and recognition, and remote control function.

[0013] Specifically, the spot processing terminal program is compiled on the IDEA platform based on the java language; after the program runs, an interactive front panel is displayed to provide the following functions for users to choose: real-time monitoring, pressure detection, state detection, remote control, serial port debugging, and instructions for use; among them, real-time detection intuitively shows the spot image when the user wears it, as well as the real-time chromaticity change curve of the sampling points and provides step counting and data export functions; the pressure detection function draws the plantar morphology by analyzing the pressure information of the user's sole; the state detection function shows the user's current motion state in real time, including sitting, standing, walking, running, and tiptoeing, and provides image and voice broadcasts; the remote control function sends infrared remote control instructions according to the user's specific actions; serial port debugging provides developer functions, allowing users to increase or modify the information band sent by the infrared module and change the remote control instructions.

[0014] An insole based on optical fiber sensing for intelligent detection and control of the present invention includes: an insole body, an integrally connected sensing structure and a camera fixing module encapsulated in the insole body; the integrally connected sensing structure includes a plurality of optical fiber sensors, which are distributed on the front of the insole body; the camera fixing module includes a signal light source and a camera infrared module, which are arranged on the back of the insole body.

[0015] Specifically, the optical fiber polished surfaces of the plurality of optical fiber sensors are arranged downward at at least four specific positions on the front of the insole, and the specific positions correspond to four center of gravity points of the sole, including two at the upper end of the sole, one at the center of the sole, and one at the heel.

[0016] Preferably, the initial diameter of the optical fiber of the optical fiber sensor is 1 mm, the polished shape is D-shaped, the remaining thickness is 0.66 mm, and the polished length is 80 mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects and advantages:

[0018] 1. The present invention integrates a sensing structure into an insole, adopts a flexible sensing module that directly encapsulates a D-type side-polished optical fiber inside the insole, and combines image processing and signal coding technologies to achieve a multi-functional, lightweight, and low-cost intelligent insole, which has important application value and market prospects. It does not affect the daily experience of the wearing user and can better reflect the core concept of flexible wearable electronics. Compared with traditional metal sensors, plastic optical fibers have a longer bending service life, stronger electromagnetic interference resistance, a softer and more comfortable wearing experience, and lower mass production costs. At the same time, the insole of the present invention can directly capture the data of the user's sole, and eliminate errors by comparing the data of multiple monitoring points, making it more accurate than traditional devices that judge the motion state by the center of gravity or heartbeat.

[0019] 2. The insole of the present invention can meet the following functions: it can collect and display the motion state change curve of the sole of the wearing user in real time, count the steps of the wearing user by analyzing the curve, and also provide a data export function for the user to record; secondly, it can provide pressure detection, directly draw the sole force distribution of the user at this time to judge whether the user has plantar lesions or correct standing posture, etc.; at the same time, it can also provide state analysis, and directly display the user's current motion state (standing, sitting, moving) by analyzing the spot data, text reminder and dynamic picture display, which is suitable for monitoring the wearing user; realize the function of remotely controlling household appliances by integrating an infrared module and using the spot signal of specific actions on the sole, achieving the interconnection of all things, liberating the hands, and providing convenience for some inconvenient users or special situations; in addition, it provides serial port debugging and standby functions to meet the needs of developers' debugging and user customization.

[0020] 3. The present invention has great potential for integrated development. In addition to the optical fiber sensing points already arranged in the insole, various other sensors can be further combined according to needs. For signal processing and communication, in addition to integrating an infrared module, Bluetooth, mobile communication, etc. can also be integrated to further expand the functions of the insole. In summary, compared with traditional sensors, it has a large market prospect and further room for growth.

[0021] 4. In short, the present invention has the following advantages: high sensitivity: obvious light intensity difference is generated in the D-type polishing area when stressed; comfortable and durable: the sensing layer is deeply buried in the insole without affecting the foot feeling, and the anti-bending life of POF ≥ 10 4 times; strong anti-interference: all-optical signal transmission does not require additional shielding and has good stability; multi-functional integration: gait monitoring, pressure imaging, state recognition, remote infrared control and developer debugging interface are integrated into one, realizing full-scenario applications "worn on the feet"; cost controllable: the costs of all key components (POF, LED, micro camera, microcontroller) are low, and it is easy to scale production. Description of the Drawings

[0022] Figure 1 It is a flowchart of a method for preparing an insole for intelligent detection and control based on fiber optic sensing according to an embodiment of the present invention.

[0023] Figure 2 It is a physical diagram of the insole of the present invention and a schematic diagram of the test running effect of part of the terminal program.

[0024] Figure 3 is a schematic diagram of the optical fibers of two insole sample types of the present invention and their strain test data, where Figure 3.1 is a schematic diagram of the sample of the D-shaped polished optical fiber under the microscope, Figure 3.2 is a schematic diagram of the tapered polished optical fiber sample, Figure 3.3 shows the corresponding spot chromaticity test data when the original fiber core diameter is retained at 2 / 3 after polishing, at different polishing lengths and strain depths (depths of 0.5 mm / 1 mm / 2 mm).

[0025] Figure 4 It is a schematic wiring diagram of the optical fiber sensors on the front and back sides of an insole for intelligent detection and control based on fiber optic sensing of the present invention before encapsulation. The upper part is the wiring diagram of the back side before encapsulation, and the lower part is the layout position diagram of the front side sensing points before encapsulation.

[0026] Figure 5 It is a schematic diagram of the front and back sides of an insole for intelligent detection and control based on fiber optic sensing of the present invention after encapsulation. The upper left part is the back side of the insole after encapsulation, and the lower left part is the front side of the insole after encapsulation. The right side shows the spot signal when the internal light source of the insole is turned on and off.

[0027] Figure 6 The shown is a test diagram of the real-time detection function, including the start video recording, step counting and data saving buttons.

[0028] Figure 7 It is a schematic diagram of the pressure detection function test of the terminal program - plantar pressure test. The spot intensities at four sampling points are captured and converted into pressure signal image points and diffusely filled to display the plantar pressure image.

[0029] Figure 8 It is a schematic diagram of the status detection function test of the terminal program. When the captured spot information is consistent with the internal status judgment, it sends text and animated GIF displays including rest, exercise, standing, etc., and at the same time, voice broadcasts.

[0030] Figure 9 It is a schematic diagram of the remote control function test of the terminal program. When the captured spot information during exercise matches the built-in instruction status, the green light of the infrared remote control module connected to the processor flashes to send a signal. Currently, it supports 7 groups of infrared instructions to control specified pre-stored and sent commands.

[0031] Figure 10It is a schematic diagram of the serial port debugging function test of the terminal program, providing users with custom interaction settings for the infrared module.

[0032] Figure 11 It is a schematic diagram of the 3D model of the camera fixing module. The camera fixing module has a square-section plug-in part extending outward along the heel of the insole. A camera is inserted into the upper socket, and the light output ends of four fiber optic sensors can be inserted into the four small sockets at the lower side.

[0033] Figure 12 It is a test mold for the fiber optic sensor, including two types of strain test benches, one is the strain depth test bench and the other is the bending angle test bench. Specific implementation mode

[0034] The present invention will be further described in detail below with reference to the accompanying drawings.

[0035] As Figure 1 shown, a method for preparing an insole based on a fiber optic sensor for intelligent detection and control of the present invention includes:

[0036] Using the side polishing technique to perform single-side polishing on the optical fiber to obtain a fiber optic sensor;

[0037] Distributing and encapsulating a plurality of the fiber optic sensors on the front of the insole body, and arranging and encapsulating a camera fixing module including a signal light source and an infrared camera module on the back of the insole body, thereby obtaining the insole.

[0038] The step of using the side polishing technique to perform single-side polishing on the optical fiber to obtain a fiber optic sensor includes: intercepting a plastic optical fiber with a length of at least 20 cm, wiping at least 1 cm length area at the center with an alcohol cotton ball, placing the optical fiber on the polishing machine, and aligning the clean area side of the optical fiber with the polishing wheel of the polishing machine for polishing until a D-shaped optical fiber with a specified depth is prepared.

[0039] Electrically connecting between a plurality of the fiber optic sensors and the camera fixing module.

[0040] The camera fixing module is provided with a plug-in part extending outward and having a square cross-section along the rear end of the insole; a socket (preferably with a diameter of 7.5 mm) is provided above the plug-in part for inserting a micro camera; four (preferably with a diameter of 1.2 mm) small sockets are arranged at the lower part of the side of the plug-in part for inserting the output ends of four fiber optic sensors; there is a flat structure connecting body between the camera fixing module and the plug-in part.

[0041] The distribution and encapsulation of multiple fiber optic sensors on the front of the insole body includes: arranging the polished surfaces of the fibers of multiple fiber optic sensors downward at at least four specific positions on the front of the insole, and the specific positions correspond to four center of gravity points of the sole of the foot, including two at the upper end of the sole, one at the center of the sole, and one at the heel.

[0042] In the present invention, by reasonably arranging sensing points on the insole, and then using spot collection and processing technology to obtain real-time spot signals, the signals are processed twice to match and display information such as the motion state of the wearing user. At the same time, communication matching is achieved with the infrared module, and the spot signals of specific actions are encoded and transmitted to achieve the remote control function. It can achieve high-sensitivity plantar pressure detection while ensuring the softness and comfort of the insole; highly integrate the sensor device and the data acquisition system, reducing external wiring and additional devices; at the same time, it can expand the traditional gait monitoring function and increase the specific action coding and infrared remote control capabilities. During detection, the connection between the camera fixed module and the processor (which can be a computer or a mobile phone) to achieve information communication is through a camera with a Typ-c interface (which can be an endoscope). Insert the micro-camera probe (with a diameter of 7 mm) into the 7.5 mm jack of the camera fixed module and fix it with glue. The other Typ-C interface of the micro-camera is connected to the processor for wired signal transmission; the USB interface of the infrared remote control module is connected to the processor, and the infrared signal transmitting end is directed at the instrument to be controlled; turn on the light source, and the processor runs the terminal program for spot detection; build a stepped strain test platform with a step depth of 0.5 - 7 mm and a step length of 0.5 mm; thus, pressure sensing tests for the insole wearing user including the following contents are realized: gait cycle detection, plantar shape drawing, motion state analysis and recognition, and remote control function.

[0043] Its spot processing terminal program is compiled on the IDEA platform based on the Java language. After the program runs, an interactive front panel is displayed to provide the following functions for users to choose: real-time monitoring, pressure detection, state detection, remote control, serial port debugging, and instructions for use. Among them, real-time detection intuitively shows the spot image when the user is wearing, as well as the real-time chromaticity change curve of the sampling points and provides the functions of step counting and data export; the pressure detection function draws the plantar shape by analyzing the pressure information of the user's sole; the state detection function shows the user's current motion state in real time, including sitting, standing, walking (running), and tiptoeing, and provides image and voice announcements; the remote control function sends infrared remote control instructions according to the user's specific actions; serial port debugging provides developer functions, allowing users to increase or change the information band transmitted by the infrared module and change the remote control instructions.

[0044] An insole for intelligent detection and control based on optical fiber sensing according to the present invention includes: an insole body, an integrally-sensed structure with electrical connection encapsulated in the insole body, and a camera fixing module; the integrally-sensed structure includes a plurality of optical fiber sensors, which are distributed on the front side of the insole body; the camera fixing module includes a signal light source and a camera infrared module, which are arranged on the back side of the insole body.

[0045] The optical fiber polishing surfaces of the plurality of optical fiber sensors are arranged downward at at least four specific positions on the front of the insole, and the specific positions correspond to four center-of-gravity points of the sole of the foot, including two at the upper end of the sole, one at the center of the sole, and one at the heel.

[0046] The initial diameter of the optical fiber of the optical fiber sensor is 1 mm, the polishing shape is D-shaped, the remaining thickness is 0.66 mm, and the polishing length is 80 mm.

[0047] The initial diameter of the optical fiber of the optical fiber sensor is 0.75 mm, the polishing shape is D-shaped, the remaining thickness is 0.5 mm, and the polishing length is 60 mm.

[0048] The optical fiber sensor uses plastic optical fiber.

[0049] Figure 2 It is a schematic diagram of the complete hardware device and software platform of the intelligent control insole based on optical fiber sensing.

[0050] The actual operation steps of the method of the present invention include:

[0051] 1. Preparation of optical fiber sensors

[0052] (1) Select plastic optical fiber with a transmission efficiency of ≥85% in the visible light band (such as 1 mm POF of Mitsubishi, Japan), cut a fiber segment with a length of ≥20 cm, and wipe the central section with an alcohol cotton to form a clean treatment area with a width of ≥1 cm;

[0053] (2) Fix the optical fiber on a four-axis linkage polishing machine (the four-dimensional adjustment accuracy of X / Y / Z / θ ≤ 1 μm), and set the grinding wheel parameters:

[0054] - Sandpaper mesh number: 5000 - 7000 mesh (preferably 6000 mesh)

[0055] - Grinding wheel speed: 2500 - 3500 r / min (preferably 3000 r / min)

[0056] - Feed speed: 0.04 - 0.10 μm / ms

[0057] - Axial movement amplitude: 0 - 40 mm

[0058] (3) A single-side polishing process using distilled water cooling is adopted to polish the clean area on a single side until a D-shaped cross-section with a depth of 33% ± 2% of the original diameter is formed (taking a 1-mm optical fiber as an example, the remaining thickness is 0.66 ± 0.02 mm, and the polishing length is 80 ± 2 mm), completing the preparation of a single-point sensor;

[0059] (4) Repeat steps (1)-(3) to prepare multiple groups of sensors of the same specification.

[0060] 2. Integration of the insole body (the insole body is made of a flexible elastomer material to ensure that the optical fiber sensor fits stably on the sole under a stressed state):

[0061] (1) Process on the reverse side of the insole:

[0062] - Circular groove (diameter adapted to CR2032 button battery)

[0063] - Double rectangular groove (size 5 × 2 × 1.5 mm, adapted to the packaged LED light source)

[0064] - Square groove (5 × 5 × 2 mm, located in the first metatarsophalangeal joint area)

[0065] The process includes: cutting a circular groove and two rectangular grooves on the reverse side of the insole with a cutting tool for placing the button battery and two white light-emitting diodes. The light-emitting diodes are fixed with a black heat shrink tube, and a 5-mm length is reserved at the front end to prevent light source leakage and fix the optical fiber. The groove depth is based on the selected button battery and the packaged diode. A square groove is opened at the upper end of the insole (corresponding to the big toe area) to place the self-locking switch for controlling the light source. Finally, a cutting tool is used to cut the path for the optical fiber and wire on the back.

[0066] (2) Set four groups of horizontally controlled areas (width 1.5 ± 0.2 cm, length matching the polishing area) on the front side of the insole, corresponding to the mechanically sensitive areas of the sole:

[0067] - The head of the first metatarsal bone (bilateral)

[0068] - The center area of the arch

[0069] - The weight-bearing area of the calcaneus

[0070] Including: Horizontally arranging optical fiber sensors at specific positions on the front side of the insole (corresponding to the four center points of the sole). The width of the horizontally controlled area on the front side is twice the width of the polishing area (normally about 1.5 cm), and the D-shaped polishing area is placed in the middle of the controlled area and closely attached to the insole downward. The excess part passes through the insole from both ends of the controlled area, so that it runs on the back of the insole.

[0071] 3. Integration of the optoelectronic system

[0072] (1) Fix the polished surfaces (curvature radius 0.5 ± 0.1 mm) of four groups of D-type fiber optic sensors downward at the center position of the controlled area, and lead both ends to the reverse side through the sides of the insole.

[0073] (2) Encapsulate the LED light source using the ultraviolet curing process (wavelength 365 nm, power 30 W):

[0074] - Sleeve the LED with a 3 mm heat shrink tube, leaving a 5 mm bare fiber optic interface

[0075] - Inject the refractive index matching glue (n = 1.49 ± 0.02) and then cure it with ultraviolet light for 30 s

[0076] (3) Integration and connection of the camera fixing module:

[0077] - Install a fiber optic interface with a hole diameter of 1.2 mm

[0078] - Set a camera aperture of 7.5 mm

[0079] - Keep the distance between the fiber optic end face and the CMOS sensor at 20 - 25 mm

[0080] Specifically include: Use a cutting knife to shear the end faces of both ends of the optical fiber flat, then insert two fibers as a group into the reserved area of the diode heat shrink tube (ensure that after the heat shrink tube heats and fixes the diode, the placed optical fiber is melted), and fill the reserved area with ultraviolet glue, irradiate and fix it with an ultraviolet lamp to avoid signal interference caused by the light source shaking during movement. This is used as the incident end (emitting end) of the optical fiber optical information. Coat the optical fiber between 5 mm from the optical fiber optical information output end (receiving end) to the end face of the output end with ultraviolet glue (do not contaminate the end face), and then insert them into the 4 round holes with a diameter of 1.2 mm reserved on the side wall of the camera fixing module respectively until the optical fiber just emerges from the other end of the aperture, and then use the ultraviolet glue curing process for encapsulation and fixing, and place the camera fixing module at the heel. The signal light source in the camera fixing module is a near-infrared laser diode.

[0081] Use cloth tape to encapsulate the entire front and back of the insole to fix the optical fiber, wire, light source, camera module and sensing detection points. At the sensing acquisition points on the front, cut four rectangular tapes separately and stick them to the encapsulation tape to ensure that the non-glue part on the back covers the sensing area (do not completely cover the horizontal controlled area). The fiber optic sensor and the camera fixing module are electrically connected through wires and pin headers.

[0082] 4. Test of pressure sensing:

[0083] Insert a micro-camera probe (with a diameter of 7 mm) into the 7.5-mm round hole above the camera fixing module and fix it with glue. Connect the Typ-C interface at the other end of the micro-camera to the processor for wired signal transmission. Connect the USB interface of the infrared remote control module to the processor, and aim the infrared signal transmitter at the instrument to be controlled. Turn on the light source and select the status detection function.

[0084] The user wears the insole and randomly switches between four actions: walking, sitting, standing, and jumping. Each action lasts for no less than 5 s. Through 73 groups of random test actions, including 15 times of sitting and standing, 23 times of standing, 31 times of walking, and 7 times of jumping, only 3 groups are misjudged, and the misjudgment rate is only 0.04%.

[0085] Further test the specific curve of the movement through the stepped strain test. Select the real-time monitoring function. Starting from a depth of 0.5 mm, press the structural points step by step, and select the data export tab under the real-time monitoring function to obtain specific data for analysis.

[0086] (1) Build Figure 12 The stepped strain test platform shown (step depth 0.5 - 7 mm, step size 0.5 mm);

[0087] (2) When applying a deformation of 0.5 - 3 mm, the spot change rate of the D-type optical fiber (polished length 8 mm) reaches 23.5 dB / mm, which is 68% higher than that of the tapered structure;

[0088] (3) At a strain of 2 mm, the signal-to-noise ratio (SNR) of the spot image reaches 42.6 dB, meeting the requirements for human gait analysis.

[0089] 5. System function implementation

[0090] (1) Achieved through a multi-threaded processing system developed on the Java platform:

[0091] - Real-time acquisition frequency: 100 Hz

[0092] - Data smoothing algorithm: Savitzky-Golay filter (window width 15)

[0093] - Pressure mapping accuracy: ≤5 kPa

[0094] (2) Infrared communication protocol support:

[0095] - Baud rate adaptive switching (9600 - 115200 bps)

[0096] - Custom instruction set (including 7 groups of encoding / sending instructions, check bit CRC-8)

[0097] The spot processing terminal program is compiled on the IDEA platform based on the Java language. It includes 10 class files such as the interactive front panel, real-time acquisition, spot processing, smoothing filtering, serial communication, image drawing, and pressure drawing. It has functions such as real-time monitoring, pressure detection, status detection, remote control, gait statistics, data saving, and serial port debugging.

[0098] Verification of technical effects

[0099] As Figure 6 shown, the present system can achieve:

[0100] The detection error of the gait cycle ≤ 1.2%

[0101] Three-dimensional reconstruction of plantar pressure distribution (resolution 2×2 mm)

[0102] The recognition accuracy of abnormal gait ≥ 92.4% (after 100 cases of clinical tests)

[0103] The described polishing machine includes a grinding wheel that can move in four dimensions and a fixture for fixing the optical fiber. The grinding wheel is controlled by four dimensions of X, Y, Z, and θ;

[0104] The rotation speed (θ) of the grinding wheel of the described polishing machine is set to 2500 - 3500 r / min.

[0105] The selected sandpaper mesh number of the grinding wheel is 5000 - 7000 mesh.

[0106] The moving amplitude of the grinding wheel along the axial direction of the optical fiber is 0 - 40 mm, and the moving speed is 0.04 - 0.10 μm / ms.

[0107] Two preferences:

[0108] First, the initial diameter of the plastic optical fiber used in the sensing area is 1 mm, the polishing shape is D-shaped, the remaining thickness is 0.66 mm, and the polishing length is 80 mm.

[0109] Second, the initial diameter of the plastic optical fiber used in the sensing area is 0.75 mm, the polishing shape is D-shaped, the remaining thickness is 0.5 mm, and the polishing length is 60 mm.

[0110] It is only necessary that the selected plastic optical fiber has excellent transmission efficiency in the visible light band.

[0111] As described above, using the manufacturing method of the present invention, various plastic optical fibers can be polished and encapsulated to prepare an insole based on an optical fiber sensor for intelligent detection and control.

[0112] Figure 3 shows the selection of the sensing optical fiber structure. Three different types and polishing lengths of optical fiber structures are compared to test the most preferred one. It includes two of them as Figure 3.1For the D-shaped optical fibers shown, the remaining polishing depth is 2 / 3. The polishing interval length of one is 4 mm and that of the other is 8 mm. The third one is as Figure 3.2 shown. The remaining polishing depth is also 2 / 3, and the conical fiber structure does not consider the polishing interval length. Then, a special trapezoidal mold is used to test the strain depth. From a depth of 0.5 mm, 1 mm, 2 mm up to 7 mm, the spot changes of the three optical fibers are tested under different strain depths. Since under the normal body weight pressure, the insole thickness change is within 3 mm, as Figure 3.3 shows the spot changes of the three optical fibers at depths of 0.5, 1 mm, and 2 mm. Among them, for the D-shaped optical fiber, the 8-mm polishing area (red in the figure) has a more obvious rectangular waveform change signal compared to the other two optical fibers in all three cases. Therefore, the preferred type of optical fiber in the present invention is the D-shaped polishing with a remaining depth of 2 / 3 and a polishing area of 8 mm.

[0113] Figure 4 shows the schematic structural diagram of the insole before encapsulation. Four polished optical fiber sensing nodes are provided on the front of the insole, showing a specific geometric distribution, which precisely corresponds to the four gravity-loaded areas of the human foot sole. Among them, the opening direction of the D-shaped polishing area is set towards the bearing surface of the insole to ensure that the sensing area is located at the outer diameter of the strain bend when pressed, optimizing the pressure sensing performance.

[0114] The layout on the reverse side of the insole includes a power module and an optical path component. The power module is positioned in the center of gravity area of the insole, corresponding to the instep part. It is designed based on the instep shape to reduce the extrusion effect caused by the relatively small force on the instep area during normal activities of instep-wearing users, thus avoiding voltage fluctuation phenomena. In the optical path component, the position of the LED light source is adjustable, and the operation process has strict requirements: the LED must be sleeved with a heat shrinkable tube first, the heat shrinkable shaping process must be implemented before injecting the ultraviolet glue, and then the optical fiber is inserted and secondary encapsulated. Reverse operation sequence will damage the structural integrity of the optical fiber during the heat shrinkage process.

[0115] The control switch is positioned in the first metatarsophalangeal joint area, designed according to the ergonomic principle, and is in a position that is not easily touched under normal movement conditions, effectively preventing mis-triggering events and improving the system reliability.

[0116] Figure 5 shows the schematic diagram of the insole after encapsulation. During this encapsulation, it is to prevent the optical fiber from easily moving its position, causing detection point errors, and at the same time making the insole more beautiful and more comfortable to wear.

[0117] Figures 6 to 10 shows the functional display diagram that the wearing user can achieve for detection and control. After the user wears the insole and runs the processing end program, by clicking the six function tabs on the front panel, different detection functions are obtained, and this function provides additional expansion. Figure 6For the real-time monitoring function, this function can display the spot and curve images of four optical fibers in real time and provide a data export function to export the curve data into a text file in txt format for detailed analysis and recording. Figure 7 For the pressure detection function, the plantar pressure information collected by four optical fibers is used to draw the plantar morphology of the user, and the health status of the user is detected by comparing the pressure distribution of a normal person's plantar. Figure 8 For the status detection function, it detects the current motion state of the user and reminds the wearing user through dynamic GIF pictures and voice broadcasts. Figure 9 For the remote control function, when the user makes a specific built-in action (such as lifting the forefoot and only the heel touching the ground for 3 seconds), the infrared module sends an infrared code to achieve remote control. Figure 10 It allows the user to directly send a communication code to the infrared module to perform custom operations, including changing the infrared code, baud rate, etc. Figure 9 、 Figure 10 During testing, the user needs to first enter the port corresponding to the infrared module in the pop-up window. The input format is "COMX", where X is the port number, which can be queried in My Computer and Device Manager. Figure 10 For the serial port debugging function, the following message encodings are supported for infrared internal function debugging:

[0118] Set the baud rate to 9600: 68 08 00FF 03 00 02 16

[0119] Set the baud rate to 19200: 68 08 00FF 03 01 03 16

[0120] Set the baud rate to 38400: 68 08 00FF 03 02 04 16

[0121] Set the baud rate to 57600: 68 08 00FF 03 03 05 16

[0122] Set the baud rate to 115200: 68 08 00FF 03 04 06 16

[0123] Reset: 68 07 00FF 07 06 16

[0124] Format: 68 07 00FF 08 07 16

[0125] Internal learning code (Group 1): 68 08 00FF 10 00 0F 16

[0126] Internal learning code (Group 2): 68 08 00FF 10 01 10 16

[0127] Internal learning code (Group 3): 68 08 00FF 10 02 11 16

[0128] Internal learning code (Group 4): 68 08 00FF 10 03 12 16

[0129] Internal learning code (Group 5): 68 08 00FF 10 04 13 16

[0130] Internal learning code (Group 6): 68 08 00FF 10 05 14 16

[0131] Internal learning code (Group 7): 68 08 00FF 10 06 15 16

[0132] Exit internal learning code: 68 07 00FF 11 10 16

[0133] Internal code sending (Group 1): 68 08 00FF 12 00 11 16

[0134] Internal code sending (Group 2): 68 08 00FF 12 01 12 16

[0135] Internal code sending (Group 3): 68 08 00FF 12 02 13 16

[0136] Internal code sending (Group 4): 68 08 00FF 12 03 14 16

[0137] Internal code sending (Group 5): 68 08 00FF 12 04 15 16

[0138] Internal code sending (Group 6): 68 08 00FF 12 05 16 16

[0139] Internal code sending (Group 7): 68 08 00FF 12 06 17 16

[0140] Figure 11 Shown is the 3D printed model of the camera module and the strain test bench. In the camera module, four fiber optic apertures are set at 1.2 mm at the lower side for inserting the light spot output ends of four optical fibers; the upper camera aperture is set at 7.5 mm for inserting a micro camera, and the cavity distance between the camera and the optical fiber is set at 28 mm (when actually installed, ensure that the distance between the camera and the optical fiber is between 20 mm and 25 mm). The overall spatial size is 2 cm in length, 2 cm in width, and 4 cm in height.

[0141] Figure 12Shown is a mold for testing the spot effect after optical fiber polishing. The depth of each step of the strain depth test bench on the left is 0.5mm - 1mm - 2mm - 3mm - 4mm - 5mm - 7mm respectively. The bending angle test bench on the right provides a bending angle of 0 - 180°, with a step size of 10°. The bending point of the optical fiber is fixed at the middle protruding cylinder.

[0142] In summary, the present invention proposes a method for preparing and detecting an insole based on optical fiber sensing for intelligent detection and control, as well as the insole itself. By using optical fiber sensing technology to receive and analyze plantar movement information in real time, it can accurately identify various foot state data, realize the monitoring of users' daily health conditions, and provide data recording and warning functions. The invention is based on the design and implementation of an intelligent wearable device using optical fiber sensing and flexible electronic materials, which promotes the development of new health monitoring and industrial Internet of Things devices and establishes a complete technical verification platform. The production of the present invention does not require large-scale equipment, the method is novel, and it is applicable to various types of plastic optical fibers. The product also has the potential to be integrated with wireless remote control technology and can execute various control instructions to meet the diverse needs of the Internet of Things era.

Claims

1. A method for preparing an insole for intelligent detection and control based on an optical fiber sensor, characterized in that The method includes: Using side polishing technology to perform single-side polishing on an optical fiber to obtain an optical fiber sensor; Distributing and encapsulating a plurality of the optical fiber sensors on the front surface of the insole body, and arranging and encapsulating a camera fixing module including a signal light source and a camera module on the back surface of the insole body, thereby obtaining the insole.

2. The preparation method of an insole for intelligent detection and control based on an optical fiber sensor according to claim 1, characterized in that, The using side polishing technology to perform single-side polishing on an optical fiber to obtain an optical fiber sensor includes: intercepting a plastic optical fiber with a length of at least 20 cm, wiping an area with a length of at least 1 cm at the center with an alcohol cotton ball, placing the optical fiber on a polishing machine, and aligning the clean area side of the optical fiber with the grinding wheel of the polishing machine for polishing until a D-shaped optical fiber with a specified depth is prepared.

3. The preparation method of an insole for intelligent detection and control based on an optical fiber sensor according to claim 1, wherein, Electrically connecting a plurality of the optical fiber sensors and the camera fixing module; the camera fixing module is provided with a plug-in member extending outward and having a square cross-section along the rear end of the insole; a jack is provided above the plug-in member for inserting a micro camera; four small-diameter jacks are arranged at the lower part of the side surface of the plug-in member for inserting the output ends of four optical fiber sensors; there is a flat structure connecting body between the camera fixing module and the plug-in member.

4. The preparation method of an insole for intelligent detection and control based on an optical fiber sensor according to claim 1, characterized in that, The distributing and encapsulating a plurality of the optical fiber sensors on the front surface of the insole body includes: arranging the optical fiber polishing surfaces of a plurality of optical fiber sensors downward at at least four specific positions on the front surface of the insole, and the specific positions correspond to four center of gravity points of the sole of the foot, including two at the upper end of the sole of the foot, one at the center of the sole of the foot, and one at the heel.

5. The preparation method of an insole for intelligent detection and control based on an optical fiber sensor according to claim 1, characterized in that, The insole body is made of a flexible elastomer material.

6. An insole detection method for intelligent detection and control based on optical fiber sensing, characterized in that, For the insole prepared by the method according to any one of claims 1-5, insert a micro camera probe with a Typ-c interface into the upper jack of the camera fixing module, and connect the other Typ-C interface of the micro camera to a processor for wired signal transmission; connect the USB interface of an infrared remote control module to the processor; turn on the signal light source, and the processor runs a spot processing terminal program; build a stepped strain test platform, and set the step depth to 0.5-7 mm and the step size to 0.5 mm; to realize pressure sensing tests on the insole-wearing user including the following contents: gait cycle detection, plantar morphology mapping, motion state analysis and recognition, and remote control function.

7. An insole detection method for intelligent detection and control based on optical fiber sensing according to claim 6, characterized in that The spot processing terminal program is compiled on the IDEA platform based on the java language; after the program runs, an interactive front panel is displayed to provide the following functions for the user to select: real-time monitoring, pressure detection, state detection, remote control, serial port debugging, and instructions for use; among them, real-time detection intuitively shows the spot image when the user wears it, as well as the real-time chromaticity change curve of the sampling points and provides functions of step counting and data export; the pressure detection function draws the plantar morphology by analyzing the pressure information of the user's sole of the foot; the state detection function shows the user's current motion state in real time, including sitting, standing, walking, running, and tiptoeing, and provides image and voice announcements; the remote control function sends infrared remote control instructions according to the user's specific actions; serial port debugging provides developer functions, allowing the user to increase or modify the information band sent by the infrared module and change the remote control instructions.

8. An insole for intelligent detection and control based on optical fiber sensing, characterized in that Including: An insole body, an electrically connected integrated sensing structure encapsulated in the insole body, and a camera fixing module; the integrated sensing structure includes a plurality of optical fiber sensors distributed on the front surface of the insole body; the camera fixing module includes a signal light source and a camera infrared module, which are arranged on the back surface of the insole body.

9. The insole for intelligent detection and control based on optical fiber sensing according to claim 8, characterized in that, The optical fiber polished surfaces of the plurality of optical fiber sensors are arranged downward at at least four specific positions on the front surface of the insole, and the specific positions correspond to four center of gravity points of the sole of the foot, including two at the upper end of the sole of the foot, one at the center of the sole of the foot, and one at the heel.

10. An insole for intelligent detection and control based on optical fiber sensing according to claim 8, characterized in that, The initial diameter of the optical fiber of the optical fiber sensor is 1 mm, the polished shape is D-shaped, the remaining thickness is 0.66 mm, and the polished length is 80 mm.

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