CN113729690A

CN113729690A - Inductance coil type pressure sensor and sensing shoe

Info

Publication number: CN113729690A
Application number: CN202111055212.6A
Authority: CN
Inventors: 刘富博; 赵建文; 张伟
Original assignee: Weihai Star Soft Robot Technology Co ltd
Current assignee: Weihai Star Soft Robot Technology Co ltd
Priority date: 2021-09-09
Filing date: 2021-09-09
Publication date: 2021-12-03

Abstract

The invention relates to an inductance coil type pressure sensor and a sensing shoe, which solve the technical problems that the existing sole pressure testing system is heavy, is not suitable for outdoor and sports measurement, and has high requirements on the use conditions of a force measuring insole and short service life; the invention is widely applied to the technical field of wearable equipment.

Description

Inductance coil type pressure sensor and sensing shoe

Technical Field

The invention relates to the technical field of wearable equipment, in particular to an inductance coil type pressure sensor and sensing shoes.

Background

In the technical field of wearable devices, during gait analysis, plantar pressure distribution is one of critical information, and it is usually combined with an inertial sensor to detect human body characteristics of each time phase during gait. In addition, gait analysis is also a key technical link in exoskeleton robot design, and it is important to accurately identify the control of gait to exoskeleton. The sole pressure distribution is one of two most important data of a person in the walking process, the sole pressure is measured and analyzed, and the correlation between the sole pressure and the angle of the lower limb joint is researched, so that the method has important significance for wearable equipment and an exoskeleton robot sensor system.

At present, a commonly used plantar pressure testing system mainly comprises a force measuring plate, a force measuring platform, a force measuring insole and a force measuring shoe. Among them, the force measuring platform and the force measuring plate have relatively high measuring accuracy, but the system is heavy, and the measurement in the open air and in the sports has limitations. The force measuring insole and the force measuring shoe have higher flexibility and are more suitable for detecting the pressure of the foot soles of the gaits.

The sensors used by the existing force-measuring insoles are mainly of piezoresistive type, and piezoresistive pressure sensors have the characteristics of excellent sensitivity and frequency response, small volume and easiness in integration. The sole pressure force measuring insole based on the piezoelectric sensor can not measure static sole pressure and has defects in function. Both of these pressure sensors are made using thin film processes. Some thin film pressure sensors available on the market, while having a performance that is durable over millions of times, have a much reduced actual life due to impact forces and physical damage. When a person walks with the shoe, the shearing force of the foot on the insole is also not negligible, so that the shoe is easy to slip in the new walking process, and a large error is generated. The real-time measurement of the plantar pressure requires that the plantar pressure measurement system not only has higher measurement accuracy, but also has a long service life to adapt to the harsh working environment of outdoor sports. Obviously, the thin film pressure insole is not suitable due to the characteristics of short service life and high requirement on the use environment.

Disclosure of Invention

The invention provides an inductance coil type pressure sensor and a sensing shoe which are completely different from the traditional force measuring principle, aiming at solving the technical problems that the existing sole pressure testing system is heavy, is not suitable for outdoor and sports measurement, and has high requirements on the use conditions of a force measuring insole and short service life.

The invention discloses an inductance coil type pressure sensor, which comprises an extension spring, a base, an elastic material body, a first lead and a second lead, wherein the extension spring is arranged on the base; the extension spring is embedded into the elastic material body and is in a stretched state; the elastic material body is fixedly connected with the base, the bottom of the extension spring is fixedly connected with the base, the first lead is connected with the tail end of the bottom of the extension spring, the first lead penetrates through the base, and the second lead is connected with the tail end of the top of the extension spring.

Preferably, the shape of the body of elastomeric material is a cylinder, an elliptical cylinder, a cube, a cuboid or a trapezoid.

Preferably, the body of elastomeric material is irregularly shaped.

Preferably, the elastic material body is made of silica gel.

Preferably, the material of the elastic material body is TPU.

Preferably, the extension spring is a helical extension spring.

Preferably, the extension spring is an extension spring that is square per turn.

The invention also provides a sensing shoe, which comprises a force measuring sole, a lead and a shoe body, wherein the shoe body is connected with the force measuring sole, the force measuring sole comprises an inductance coil type pressure sensor, a supporting layer, a deformation layer and a protective layer, the inductance coil type pressure sensor is fixedly connected with the supporting layer, the deformation layer is bonded with the supporting layer, the deformation layer is provided with a sensor accommodating hole, and the lead is placed on the upper surface of the deformation layer; the protective layer is bonded with the deformation layer;

the inductance coil type pressure sensor comprises an extension spring, a base, an elastic material body, a first lead and a second lead; the extension spring is embedded into the elastic material body and is in a stretched state; the elastic material body is fixedly connected with the base, the bottom of the extension spring is fixedly connected with the base, the first lead is connected with the tail end of the bottom of the extension spring, the first lead penetrates through the base, and the second lead is connected with the tail end of the top of the extension spring;

the elastic material body of the inductance coil type pressure sensor is arranged in the sensor accommodating hole of the deformation layer; the first and second wires are connected to the leads.

Preferably, the shoe body is connected with a circuit board, and the lead is connected with the circuit board.

The invention also provides an inductance coil type pressure sensor, which comprises an extension spring, an elastic material body, a first lead and a second lead; the extension spring is embedded into the elastic material body and is in a stretched state; the first wire is connected with the tail end of the bottom of the extension spring, and the second wire is connected with the tail end of the top of the extension spring.

The invention has the advantages of brand new design idea, brand new measurement principle, high measurement precision and low cost of the inductance coil type pressure sensor, small volume, better durability and longer service life.

The sensing shoes have high measurement accuracy and low cost, and have long service life to adapt to the harsh working environment of outdoor sports. Static and dynamic plantar pressures can be measured. The sole of the sensing shoe is not easy to slip due to the adoption of a raised structure.

Further features and aspects of the present invention will become apparent from the following description of specific embodiments with reference to the accompanying drawings.

Drawings

FIG. 1 is an overall schematic view of a sensory shoe;

FIG. 2 is a view showing the structure of the main body and the detecting portion of the shoe;

FIG. 3 is a structural view of the sole;

FIG. 4 is a process diagram of spring clamping during the sensor fabrication process;

FIG. 5 is a schematic view of a base of the sensor;

FIG. 6 is a schematic view of a cut PVC pipe;

FIG. 7 is a schematic view of the upper cover;

FIG. 8 is a process diagram of silicone gel infusion, curing, and mold stripping in a sensor fabrication process;

FIG. 9 is a schematic view of the overall structure of the sensor;

FIG. 10 is a schematic view of a sensor under pressure;

FIG. 11 is a circuit diagram of inductance detection;

FIG. 12 is a basic schematic;

FIG. 13 is a sensor layout;

FIG. 14 is a block diagram of a deformation layer of the force measuring sole;

fig. 15 is an overall structural view of a sensor having an extension spring of which each turn is square;

fig. 16 is a schematic structural view of an induction coil type pressure sensor made of an enameled wire.

The symbols in the drawings illustrate that:

10. the device comprises a sensing shoe, 11 force measuring soles, 111 inductance coil type pressure sensors, 111-1 extension springs, 111-2 first lead wires, 111-3 thermoplastic tubes, 111-4 bases, 111-5 silica gel cylinders and 111-6 second lead wires; 112. the structure comprises a supporting layer, a groove 112-1, a deformation layer 113, a protective layer 114; 12. the detection device comprises a detection device, a circuit board, a fixing piece, a shielding shell, a shoe body, a magic buckle, a shielding shell groove and a connecting groove, wherein the detection device comprises 121, the circuit board, 122, the fixing piece, 123, the shielding shell, 13, the shoe body, 131, the magic buckle and 132; 20, a PVC pipe, 30, an upper cover, 40, a fixed steel sheet and 50, a silicon rubber collagen liquid layer. 60. Each circle is a square extension spring, 70 is a square base, 80 is a silica gel cube, 90 is a spiral inductance coil, and 100 is a silica gel body.

Detailed Description

The present invention will be described in further detail below with reference to specific embodiments thereof with reference to the attached drawings.

Example 1

As shown in fig. 1-3, the sensing shoe 10 includes a force measuring sole 11, a detecting device 12, and a shoe body 13, wherein the shoe body 13 is connected to the force measuring sole 11. The detecting device 12 includes a circuit board 121, a fixing member 122, and a shielding shell 123, the circuit board 121 is adhered to the shoe body 13 by glue, the shoe body 13 is provided with a shielding shell groove connecting groove 132, the shielding shell 123 is fixedly mounted on the shielding shell groove connecting groove 132 by four fixing members 122 (the fixing member 122 may adopt screws, rivets, etc.), and the shielding shell 122 covers the circuit board 121. The shoe body 13 is provided with a magic buckle 131 for fixing. The force measuring sole 11 comprises an inductive coil pressure sensor 111, a support layer 112, a deformation layer 113 and a protective layer 114.

The process for manufacturing the inductance coil type pressure sensor 111 will be described below.

The manufacturing process of the inductor coil type pressure sensor 111 takes a specific parameter as an example. As shown in fig. 4 (a), an extension spring having a diameter of 10mm (a material of 304 spring steel, preferably a spring having a small rigidity) is selected to weld the first wire 111-2 and the end of the bottom of the extension spring 111-1 together in advance, and the welded portion is sealed using a thermoplastic tube 111-3, as shown in fig. 4 (a). The first conductive line 111-2 is then passed through the lead hole 111-4-1 of the base 111-4. Base 111-4 As shown in FIG. 5, the upper surface of base 111-4 has a connection groove 111-4-2 that can be tightly attached to the spring, base 111-4 has a lead hole 111-4-1, and the base also has a circular enclosure 111-4-3. The bottom of the tension spring 111-1 is inserted into the coupling groove 111-4-2 and electric welding paste is injected into the coupling groove to firmly adhere the bottom of the tension spring 111-1 and the coupling groove of the base together, as shown in fig. 4 (b).

The PVC pipe 20 is cut to a length of 20mm, as shown in FIG. 6, to ensure that the upper and lower ports are flat. The lower end of the transparent PVC pipe 20 is snapped into the inside of the circular enclosure 111-4-3 of the base 111-4 to position the PVC pipe 20 on the base as shown in fig. 4 (b). Several circles of raw material belts can be wound at the lower end of the PVC pipe to ensure the close fit of the pipe and the lower cover.

The upper cap 30 is then snapped over the upper end of the PVC pipe 20. As shown in FIG. 7, the upper cover is provided with a through hole 30-1, and the diameter of the through hole 30-1 is slightly larger than that of the extension spring 111-1 (the spring is hooked by using a hook). Then, the top of the tension spring 111-1 is pulled out from the through hole 30-1 of the upper cover using a hook and the top of the tension spring 111-1 is positioned at a distance above the upper cover, the fixing steel piece 40 is placed on the surface of the upper cover, and the tension spring is maintained in a pre-tensioned state using the fixing steel piece 40 inserted into the gap of the upper portion of the tension spring. As shown in fig. 4, panel (c).

Then preparing a silica gel stock solution:

1) firstly, measuring A, B of red leaf silicone rubber stock solution by using a precision scale according to m_{Stock solution A}:m_{Stock solution B}Mix at a ratio of 1: 1.

2) Into the mixed red leaf silicon rubber stock solution A, BAccording to m_{Stock solution A}：m_{Stock solution B}：m_IsooctaneIsooctane was added as a diluent at 5:5:1 to ensure adequate flowability when filling the silicone rubber. The silicon rubber can not be cured due to excessive diluent, the flowability of the silicon rubber can be influenced due to too little diluent, and the ratio of 5:5:1 is proper, so that the flowability requirement can be met and the curing effect is not influenced. The addition of the diluent isooctane was performed on a precision scale.

3) Placing the silastic collagen liquid prepared in the step 2) into a planetary mixer, setting parameters of the planetary mixer, mixing for 2 minutes at a rotating speed of 2000-2300 r/min, and defoaming for 1 minute at a rotating speed of 1900-2100 r/min. (the silicone rubber stock A, B and isooctane mixed very uniformly at this parameter).

4) Injecting the prepared silastic liquid prepared in step 3) into the PVC pipe 20 from the top of the extension spring in the mold composed of the base, the PVC pipe, the extension spring, the upper cover, and the fixing steel sheet shown in fig. 4 (c) using a medical syringe to form a silastic liquid layer 50, as shown in fig. 8 (a).

5) The mold is placed into a high-low temperature test chamber (the parameters are set to be 80 ℃, and the time is 30 minutes) to solidify the silicone rubber liquid layer 50 so as to form a silicone cylinder 111-5 (at this time, the extension spring is embedded into the silicone cylinder 111-5, and the extension spring is sealed in the silicone), and the silicone cylinder 111-5 is adhered to the base 111-4), or is solidified at normal temperature.

6) The fixing steel piece 40 is removed and then the upper cover 30 is removed. The PVC pipe is separated from the silica gel cylinder 111-5 by direct drawing, the PVC pipe is removed, and the base 111-4 is retained, as shown in fig. 8 (b). The extra coils of spring above the upper surface of the silicone cylinder 111-5 are removed with scissors, a second wire 111-6 is used to weld with the end of the top of the tension spring, and the welded part is sealed with thermoplastic, as shown in fig. 8 (c), to complete the manufacture of the solenoid pressure sensor 111, and at this time, the tension spring in the finished product of the solenoid pressure sensor 111 is still in a tension state. As can be seen, the inductance coil type pressure sensor 111 is mainly composed of an extension spring 111-1, a first lead 111-2, a base 111-4, a silica gel cylinder 111-5, and a second lead 111-6.

The overall three-dimensional shape of the inductance coil type pressure sensor 111 is not limited to a cylindrical shape, and may be other regular three-dimensional shapes such as an elliptical cylinder, a cube, a rectangular parallelepiped, and a trapezoidal body, or may be an irregular three-dimensional shape. When the whole sensor is an elliptic cylinder, the extension spring is embedded into the silica gel elliptic cylinder, the bottom of the extension spring is fixedly connected with the elliptic base, the first lead passes through the elliptic base, and the elliptic PVC pipe and the elliptic upper cover are used in the corresponding manufacturing process. When the whole sensor is a cube, the extension spring is embedded into the silica gel cube, the bottom of the extension spring is fixedly connected with the square base, the first lead penetrates through the square base, and the tube with the square cross section and the square upper cover are used in the corresponding manufacturing process. When the whole cuboid that is of sensor, extension spring during the embedding silica gel cuboid, extension spring's bottom and rectangle base fixed connection, first wire passes from the rectangle base, uses the cross section to be rectangular pipe and rectangle upper cover in the corresponding manufacturing process. When the whole sensor is a trapezoid body, the extension spring is embedded into the silica gel trapezoid body, the bottom of the extension spring is fixedly connected with the rectangular base, the first lead penetrates through the rectangular base, and the tube with the trapezoidal longitudinal section and the rectangular upper cover are used in the corresponding manufacturing process.

It should be noted that the material for encapsulating the extension spring is not limited to silicone, and may be other elastic materials such as TPU.

The finished product of the inductance coil type pressure sensor may not include a base, and for example, the finished product of the inductance coil type pressure sensor mainly includes an extension spring 111-1, a first lead 111-2, a silicone cylinder 111-5, and a second lead 111-6.

The pressure sensor 111 of the inductor coil type has a good ability of compressing and restoring shape, so when the pressure of the foot of a person acts on the axial direction of the sensor, the sensor is compressed by the pressure, the extension spring 111-1 inside the sensor is compressed along with the deformation of the silicone cylinder 111-5 (the extension spring in the silicone cylinder 111-5 is in a stretched state), and the inductance value of the sensor changes (the extension spring 111-1 is essentially an inductance coil), so that the pressure can be detected by detecting the change of the inductance value. The specific principle is as follows:

the inductance value of the tension spring 111-1 can be represented by the following formula (1):

in the formula (1), mu represents the magnetic permeability of the medium, namely the magnetic permeability of the silica gel cylinder 111-5; d_nRepresents the coil diameter, i.e. the diameter of the tension spring; n represents the number of coil turns and x represents the length of the coil. For a given parameter of the spring, the spring is in tension and compression mu, D_nN are kept constant, it is clear that the longer the length of the spring, the smaller the inductance value l (x).

As shown in fig. 10, the extension spring is sealed in the silicone, when the sensor is pressed by the sole of the foot, the silicone cylinder 111-5 will deform, and the extension spring will deform accordingly, as shown in the right view of fig. 10, that is, the length x of the spring becomes smaller, and the inductance value becomes larger. The deformation quantity of the spring is positively correlated with the plantar pressure, and the inductance value is positively correlated with the spring deformation quantity delta X. The plantar pressure is positively correlated with the inductance value of the spring. Therefore, through a calibration experiment, the pressure applied to the sensor and the inductance value of the sensor are directly calibrated. The pressure value of the sensor can be known by measuring the inductance value of the extension spring.

A method of detecting the inductance value of the sensor is described below.

As shown in FIGS. 11 and 12, the two pins of the MCU singlechip, PA4 and PA5, are used as the two output channels of the DAC to output step sine waves 180 degrees out of phase. The second resistor R2, the second capacitor C2, the third resistor R3 and the third capacitor C3 respectively form a first-order low-pass RC filter, and the step sine waves output by the DAC are filtered to obtain smooth sine waves. Then respectively converting impedance through a voltage follower, and applying the impedance as an excitation signal to a resistor R1 and a resistance Z to be measured_xBoth ends (here Z_xIs an extension spring in the inductive coil pressure sensor 111). FIG. 12 shows a basic schematic diagram, A, B, CThe nodes are three points to be sampled, and the voltage acquisition is completed by impedance conversion through the voltage follower shown in fig. 11 and then adding the impedance conversion to the PA2, PA1 and PA7 (namely ch2, ch1 and ch7 of the ADC).

As shown in U of FIG. 12_iFor sinusoidal excitation signals, R1 is a current limiting resistor. Let the vectors of the A, B, C three-point positions be respectively

A. The voltage vector between B two points is

B. The voltage vector between the two points C is

R1 and Z_XAre connected in series, so that the currents are equal, and the current vector is

From the circuit basis, the following formula can be derived:

the current vector can also be represented by the following formula (4):

impedance Z_XCan be expressed by the following formula (5):

in the formula (5), the first and second groups,

and

the two vectors can be represented as:

wherein, a, b, c and d are the projection values of the two vectors on the coordinate axis respectively.

Voltage vector ratio

It can be expressed as:

in the formula (6), the first and second groups,

calculating the vector ratio

The values of X and Y can be determined according to the equations (7), (8)

Z_x＝R_x+jωL_x (7)

Further obtaining inductance L_x：

The process of mounting the inductor coil type pressure sensor 111 to the shoe will be described.

To apply the coil-type pressure sensor 111, as shown in fig. 2 and 3, the manufacturing process of the sensing shoe is described as follows:

8 inductance coil type pressure sensors are arranged on the supporting layer 112 of the force measuring sole 11, as shown in the arrangement position in fig. 13, the number of the sensors is totally 8 from top to bottom, and the number 1 sensor is used for detecting the plantar pressure of the first phalanx area; the No. 2 sensor is used for detecting the sole pressure of the second to fifth phalanx areas; the No. 3 sensor and the No. 5 sensor are used for detecting the plantar pressure of the middle and outer sides of the foot; the No. 4 sensor is used for detecting the plantar pressure of the inner side of the middle of the foot, the partial pressure is related to the flat foot, and the No. 4 sensor is not arranged if the flat foot is not arranged; no. 6, No. 7 and No. 8 sensors are used for detecting the pressure of the foot root. The soft inductive coil sensor 111 is arranged on the support layer 112 of the sole according to the above-mentioned layout, as shown in fig. 3, the support layer 112 is provided with a groove 112-1, the diameter of the groove 112-1 is the same as that of the base of the sensor, and the base of the sensor is embedded in the groove 112-1 and is adhered by glue, so that the sensor can be reliably fixed on the support layer 112. For the material of the supporting layer 112, a harder material, such as synthetic rubber, is preferably selected to ensure the accuracy of the pressure value measurement.

The next step is to bond the deformation layer 113 of the sole to the support layer 112. As shown in fig. 3, the deformation layer 113 is provided with a circular hole 113-4 for accommodating the sensor, and the silicone cylinder of the sensor is disposed in the circular hole 113-4 on the deformation layer 113 (it is further preferable that the diameter of the circular hole 113-4 on the deformation layer 113 is larger than the diameter of the silicone cylinder of the sensor, that is, there is a certain distance between the inner wall of the circular hole 113-4 and the outer wall of the silicone cylinder of the sensor). As shown in FIGS. 3 and 14, the upper surface of the transformation layer has a wiring groove 113-3 for arranging the lead wires of the sensor. The deformability of the material of the deformation layer and the sensor material is approximate to be appropriate, and Polyurethane (PU), rubber, EVA and the like can be selected as the material of the deformation layer. As shown in fig. 3 and 14, a plurality of protrusions 113-1 are connected to the upper surface 113-2 of the transformation layer 113, and the height of the protrusions 113-1 may be 3 mm. After the deformation layer 113 is bonded with the supporting layer 112, the upper surface of the sensor is higher than the upper surface 113-2 of the deformation layer 113 by about 3mm, under the condition, when a tester wears the sensing shoes to test, the comfort level is better, strong discomfort cannot be generated, the gait cannot be influenced, on one hand, the comfort level of treading on the foot can be increased by the plurality of bulges 113-1, and on the other hand, the friction force can be increased.

It should be noted that the plurality of protrusions 113-1 may not be disposed on the upper surface 113-2 of the deformation layer 113, and the entire upper surface 113-2 of the deformation layer 113 is a plane, in this case, the upper surface of the sensor is flush with the upper surface 113-2 of the deformation layer 113, or the upper surface of the sensor is slightly lower than the upper surface 113-2 of the deformation layer 113, or in short, the upper surface of the sensor is not higher than the upper surface 113-2 of the deformation layer 113.

Next, as shown in fig. 3, the protective layer 114 is bonded to the transformation layer 113. The protective layer is made of light, thin and soft materials, such as PDMS films and silicon rubber films. The protective layer 114 covers the leads and the deformation layer 113, further improving comfort during walking. While preventing the wire from breaking due to shear forces during travel. And finishing the force measuring sole part.

It will be understood by those skilled in the art that the wiring groove 113-3 may not be formed on the upper surface of the deformation layer 113, and leads connected to two wires of the sensor may be directly placed on the upper surface of the deformation layer 113.

The force measuring sole is the core part of the force measuring shoe. The force measuring sole 11 and the shoe body 13 are sewn together, and after the circuit board is arranged, all the lead wires are connected with the circuit board, so that the sensing shoe is manufactured. It should be noted that, the sensing shoe may not be equipped with a circuit board, and two wires of the sensor are connected with an external measuring circuit board.

For the specific structure of the inductance coil type pressure sensor, the spiral type tension spring 111-1 can be replaced by other shape tension springs, for example, by a square type tension spring with each turn, as shown in fig. 15, the square type tension spring 60 with each turn is embedded in the silicone cube 80, the bottom of the square type tension spring 60 with each turn is fixedly connected with the square base 70, and the bottom of the silicone cube 80 is fixedly connected with the square base 70.

Example 2

According to the structure and principle of embodiment 1, the inductance coil type pressure sensor can be manufactured by using an enameled wire, the enameled wire is wound in a spiral shape on a cylinder, then the cylinder is removed, so that a spiral inductance coil is formed, a silica gel body encapsulating the spiral inductance coil is formed by a 3D printing technology, and the spiral inductance coil 90 is embedded in the formed silica gel body 100, as shown in fig. 16. The specific three-dimensional shape of the 3D printing molded silica gel body can be other regular three-dimensional shapes such as a cylinder, an elliptical cylinder, a cube, a cuboid and a trapezoid body, and the 3D printing molded silica gel body can also be an irregular three-dimensional shape. And welding a conducting wire with the tail end of the top of the spiral inductance coil and welding a conducting wire with the tail end of the bottom of the spiral inductance coil to form a sensor finished product. It should be noted that, the manufacturing process for manufacturing the inductance coil type pressure sensor by using the enameled wire may also be as follows: preparing a silica gel cylinder, winding the enameled wire on the silica gel cylinder to form a semi-finished product in a spiral shape, then putting the semi-finished product into a cylinder mould, wherein a certain distance exists between the inner wall of the cylinder mould and the outer wall of the silica gel cylinder, the central axis of the cylinder mould coincides with the central axis of the silica gel cylinder, then pouring silica gel stock solution into the cylinder mould, and after the silica gel stock solution is solidified, sealing the enameled wire wound on the silica gel cylinder, so that the spiral inductance coil is embedded into the formed silica gel body, and finally removing the cylinder mould.

The above description is only for the purpose of illustrating preferred embodiments of the present invention and is not to be construed as limiting the present invention, and it is apparent to those skilled in the art that various modifications and variations can be made in the present invention. It will be appreciated by those skilled in the art that other configurations of parts, drive devices and connections can be made without departing from the spirit of the invention, and similar arrangements and embodiments can be devised without departing from the invention.

Claims

1. An inductance coil type pressure sensor is characterized by comprising an extension spring, a base, an elastic material body, a first lead and a second lead; the extension spring is embedded in the elastic material body and is in a stretching state; the elastic material body is fixedly connected with the base, the bottom of the extension spring is fixedly connected with the base, the first lead is connected with the tail end of the bottom of the extension spring, the first lead penetrates through the base, and the second lead is connected with the tail end of the top of the extension spring.

2. The coiled-inductor pressure sensor of claim 1, wherein the elastomeric body is in the shape of a cylinder, an elliptical cylinder, a cube, a cuboid, or a trapezoid.

3. The coiled inductive pressure sensor of claim 1, wherein the body of resilient material is irregularly shaped.

4. An inductor coil pressure sensor according to claim 1, 2 or 3, wherein the elastic material body is made of silicone.

5. An inductor coil pressure sensor according to claim 1, 2 or 3, characterized in that the material of the body of elastic material is TPU.

6. The inductive coil pressure sensor of claim 1, wherein said extension spring is a helical extension spring.

7. The coiled-inductance pressure sensor according to claim 1, wherein the extension spring is a square-shaped extension spring per one turn.

8. A sensing shoe is characterized by comprising a force measuring sole, a lead and a shoe body, wherein the shoe body is connected with the force measuring sole, the force measuring sole comprises an inductance coil type pressure sensor, a supporting layer, a deformation layer and a protective layer, the inductance coil type pressure sensor is fixedly connected with the supporting layer, the deformation layer is bonded with the supporting layer, the deformation layer is provided with a sensor accommodating hole, and the lead is placed on the upper surface of the deformation layer; the protective layer is bonded with the deformation layer;

the inductance coil type pressure sensor comprises an extension spring, a base, an elastic material body, a first lead and a second lead; the extension spring is embedded in the elastic material body and is in a stretching state; the elastic material body is fixedly connected with the base, the bottom of the extension spring is fixedly connected with the base, the first lead is connected with the tail end of the bottom of the extension spring, the first lead penetrates through the base, and the second lead is connected with the tail end of the top of the extension spring;

the elastic material body of the inductance coil type pressure sensor is arranged in the sensor accommodating hole of the deformation layer; the first and second wires are connected to a lead.

9. The sensing shoe of claim 8, wherein a circuit board is connected to the shoe body, and the leads are connected to the circuit board.

10. An inductance coil type pressure sensor is characterized by comprising an extension spring, an elastic material body, a first lead and a second lead; the extension spring is embedded in the elastic material body and is in a stretching state; the first lead is connected with the tail end of the bottom of the extension spring, and the second lead is connected with the tail end of the top of the extension spring.