CN204815604U - Trainer is assisted in dash - Google Patents

Abstract

The utility model relates to a trainer is assisted in dash, including three -dimensional dynamometry race starter, gait recognition cell, sensing system signal processor, the front running board of three -dimensional dynamometry race starter, be equipped with footboard interval acquisition unit on the bumper step respectively, off angle acquisition unit, at the front running board, the three -dimensional power pressure sensor who accepts to press force information in the sole has been put to the equipartition on the atress inclined plane of bumper step, pressure sensor gives sensing system signal processor with the signal transmission who gathers, with sensing system signal processor wireless connection's gait recognition cell including setting up in interbedded sole pressure sensor of shoes and radio communication unit. The utility model discloses a prorsad horizontal motive force, used time and the equilibrant of maxmizing power are taken all factors into consideration to the atress process of trainer is assisted in dash, real -time measurement sportsman race starter when the start of a race to obtain the off posture of the best.

Description

Sprint training aiding device

Technical Field

The invention belongs to the technical field of auxiliary exercise training, relates to sprint exercise, and particularly relates to an auxiliary sprint training device.

Background

For short distance races such as 100m, 200m and 400m races, thousandths of a second are important to the athlete because of the short race time. Therefore, effective starting is one of the key factors for achieving the success of the race. Squat starting is an international advanced mainstream short-distance starting mode, is a starting technology of a complete sprint technology, and influences the exertion of subsequent technologies and the psychological state during competition. The squat starting posture enables the body to quickly get rid of the static state, and obtains positive pedaling and stretching power and forward maximum pedaling force, thereby creating conditions for acceleration after starting. In the squat starting process, when the athlete pedals off the starting device, the sole of the foot is almost vertical to the starting device, so the pedaling force is the largest, the acceleration is the largest, and the athlete can naturally and rapidly get out of the static state to reach a higher speed as soon as possible.

According to the principle of acting force and reacting force, the bigger the forward pushing force obtained by the athlete is, the bigger the starting acceleration is, whether the forward horizontal acceleration is beneficial to obtaining can be used as the basis of the starting mode, the horizontal forward acceleration is determined by the horizontal impulse at the moment of leaving the pedal, namely the force magnitude, the time and the force direction, and the force direction depends on the angle between the pedal and the ground. Optimal starting positions take into account a combination of forward horizontal pushing force, time taken to reach maximum force and equilibrium force.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a sprint training aid, wherein a sensor for collecting sole pressure information is arranged on a stress inclined plane of a starting pedal, and a starting mode which ensures that the larger the forward horizontal pushing force of a person to be trained is, the smallest balanced tangential force can be found out according to the law of conservation of momentum by analyzing pressure data and the shortest time for achieving the maximum force can be simultaneously used.

The technical scheme of the invention is as follows: the sprint training assisting device comprises a three-dimensional force measuring starting device, gait recognition units and a sensing system signal processor, wherein a pedal space acquisition unit and a starting angle acquisition unit are respectively arranged on a front pedal and a rear pedal of the three-dimensional force measuring starting device, three-dimensional force pressure sensors for receiving plantar pressure information are respectively arranged on stress inclined planes of the front pedal and the rear pedal, the pressure sensors transmit acquired signals to the sensing system signal processor, and the gait recognition units which are in wireless connection with the sensing system signal processor comprise a plantar pressure sensor and a wireless communication unit which are arranged on a shoe interlayer. Five groups of foot sole pressure sensors are arranged on each foot, three groups of front soles of the shoe interlayers are arranged and used for measuring the reaction force of the pedals to the feet, and two groups of toe parts of the shoe interlayers are arranged and used for measuring the reaction force of the ground to the feet. The sensing system signal processor comprises a signal conversion amplifying unit, a data processing unit and a controller which are connected in sequence, the controller is used for receiving data output by the data processing unit and analyzing and calculating optimal data for determining a sprint training index, the data processing unit comprises a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, the data filtering unit is used for filtering error data collected by a sensor, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data of the data classifying unit and outputs a two-dimensional data table, and the database is used for storing detection data and standard data. The sensing system signal processor further comprises an information input unit, wherein the information input unit comprises information of the sprint athlete, and the information comprises height, weight, leg indexes and step indexes.

The pressure sensor comprises an X-direction differential capacitance unit combination and a Y-direction differential capacitance unit combination, wherein the X-direction differential capacitance unit combination and the Y-direction differential capacitance unit combination respectively comprise more than two capacitance unit modules which mutually form differential, the capacitance unit modules adopt comb tooth structures consisting of more than two strip-shaped capacitance units, each strip-shaped capacitance unit comprises a driving electrode of an upper polar plate and an induction electrode of a lower polar plate, and the normal force of the capacitance sensor is calculated by summing capacitance values of the X-direction differential capacitance unit combination and the Y-direction differential capacitance unit combination and the influence of the tangential force is eliminated.

The width of a driving electrode and the width of an induction electrode of each strip-shaped capacitance unit of the sprint auxiliary training device are the same, the length of the driving electrode is greater than that of the induction electrode, and left difference positions delta are reserved at two ends of the length of the driving electrode respectively_{Left side of}And the right difference position delta_{Right side}，b0_{Driving device}＝b_{Feeling of 0}+δ_{Right side}+δ_{Left side of}Wherein b is_{0 drive}Length of the driving electrode of the strip-shaped capacitor unit, b_{Feeling of 0}The length of the induction electrode of the strip-shaped capacitance unit. The difference delta_{Left side of}＝δ_{Right side}And is andwherein d is₀Is the thickness of the elastic medium, G is the shear modulus, τ, of the elastic medium_maxThe maximum stress value. The driving electrodes and the sensing electrodes of the strip-shaped capacitor units of the two groups of capacitor unit modules which mutually form the differential are provided with initial dislocation offsets along the width direction, and the dislocation offsets have the same size and opposite directions. The comb-shaped structure comprises more than 20 strip-shaped capacitor units and leads connected with the strip-shaped capacitor units in a one-to-one correspondence manner, and an electrode distance a is arranged between every two adjacent strip-shaped capacitor units_δ. The parallel plate area S ═ M (a)₀+a_δ)b₀Wherein M is the number of the strip-shaped capacitor units, b₀Is the length of the strip-shaped capacitor unit, a₀The width of the strip-shaped capacitor unit. And the lead of each strip-shaped capacitor unit of the capacitor unit module is connected to the signal processor of the sensing system in parallel or independently. Width of the strip-shaped capacitor unitWherein d is₀E is the Young's modulus of the elastic medium, and G is the shear modulus of the elastic medium. An intermediate converter is arranged between the sensing system signal processor and the capacitance unit module and is used for setting the transmission coefficient of voltage to capacitance or frequency to capacitance.

The invention has the following positive effects: the sprint training aid provided by the invention measures the stress process of the starting device of the athlete in real time when starting, and comprehensively considers the forward horizontal pushing force, the time for reaching the maximum force and the balance force so as to obtain the optimal starting posture. The capacitance pressure sensor effectively uses the area of a flat plate, effectively solves the coupling between three-dimensional forces by methods such as differential motion and the like, and utilizes a special strip-shaped capacitance structure to ensure that normal direction and tangential direction conversion reach higher linearity, precision and sensitivity.

Drawings

Fig. 1 shows a stripe-shaped capacitor unit and its coordinate system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a stripe-shaped capacitor unit according to an embodiment of the invention.

Fig. 3 is a schematic diagram of right-direction shift of a stripe-shaped capacitor unit according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of left-shift of a stripe-shaped capacitor unit according to an embodiment of the present invention.

Fig. 5 is an initial misalignment map of a pair of striped capacitor cells in accordance with an embodiment of the present invention.

Fig. 6 is a graph of the offset of the strip capacitor unit after stress according to the embodiment of the invention.

FIG. 7 is a diagram of a parallel plate three dimensional force pressure sensor configuration according to an embodiment of the present invention.

FIG. 8 is a diagram of a parallel plate three dimensional force pressure sensor drive electrode configuration according to an embodiment of the present invention.

FIG. 9 is a diagram of a parallel plate three-dimensional force pressure sensor sensing electrode configuration according to an embodiment of the present invention.

Fig. 10 is a graph of the output response summation achieved by the same transfer coefficient K for an embodiment of the present invention.

FIG. 11 is a signal differential schematic of a cell capacitor pair according to an embodiment of the present invention.

Figure 12 is a cross-sectional structure of a parallel plate capacitor of an embodiment of the present invention.

FIG. 13 is a starting block diagram of an embodiment of the present invention.

The PCB comprises an upper PCB substrate 1, a lower PCB substrate 2, a driving electrode 3, a sensing electrode 4, an elastic medium 5 and a plurality of electrodes.

Detailed Description

The following description of the embodiments with reference to the drawings is provided to describe the embodiments of the present invention, and the embodiments of the present invention, such as the shapes and configurations of the components, the mutual positions and connection relationships of the components, the functions and working principles of the components, the manufacturing processes and the operation and use methods, etc., will be further described in detail to help those skilled in the art to more completely, accurately and deeply understand the inventive concept and technical solutions of the present invention.

The main ideas of the invention are as follows: in squat starting, instantaneous impulse is obtained by means of the counterforce on the starting device, the impulse determines the maximum speed of starting, the impulse is the maximum stress on the starting device and the time reaching the maximum stress, the product of the force and the time is the impulse, when the maximum time is reached, the sole leaves the starting device, and the reaction time is also indicated in the time.

The utility model provides a training device is assisted in sprinting, including three-dimensional dynamometry starting gear, gait recognition unit, sensing system signal processor, three-dimensional dynamometry starting gear's preceding footboard, be equipped with footboard interval acquisition unit on the back footboard respectively, start angle acquisition unit, three-dimensional force pressure sensor who accepts plantar pressure information has all been arranged on the atress inclined plane of preceding footboard, back footboard, pressure sensor sends the signal of gathering for sensing system signal processor, gait recognition unit with sensing system signal processor wireless connection is including setting up in the sole pressure sensor and the wireless communication unit of shoe intermediate layer, sole pressure sensor adopts three-dimensional force pressure sensor.

Five groups of foot sole pressure sensors are arranged on each foot, three groups of front soles of the shoe interlayers are arranged and used for measuring the reaction force of the pedals to the feet, and two groups of toe parts of the shoe interlayers are arranged and used for measuring the reaction force of the ground to the feet.

The sensing system signal processor comprises a signal conversion amplifying unit, a data processing unit and a controller which are connected in sequence, the controller is used for receiving data output by the data processing unit and analyzing and calculating optimal data for determining a sprint training index, the data processing unit comprises a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, the data filtering unit is used for filtering error data collected by a sensor, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data of the data classifying unit and outputs a two-dimensional data table, and the database is used for storing detection data and standard data.

The sensing system signal processor further comprises an information input unit, wherein the information input unit comprises information of the sprint athlete, and the information comprises height, weight, leg indexes and step indexes.

The specific operation flow is as follows, the pedal distance acquisition unit acquires the distance between a front pedal and a rear pedal, the front pedal starting angle and the rear pedal starting angle of the starting angle acquisition unit, the palm pedal reaction force acquired by the sole pressure sensor and the ground reaction force acquired by the toe pressure sensor, the acquired data are transmitted to the data processing unit through the signal conversion and amplification unit, the data processed by the data processing unit are transmitted to the controller, the controller is combined with the information input unit to input various detailed data such as height, weight, leg indexes and step indexes to perform analysis processing, data curve graphs of different parameters are obtained, and the optimal pedal distance, the front pedal starting angle and the rear pedal starting angle are deduced.

According to the invention, the reaction force of the half sole pedal and the reaction force of the ground, which are acquired by the sole pressure sensor, are simultaneously acquired, the data are fused, the intentional effect is further improved, different data curve graphs are respectively obtained from the parameter information of different athletes, and the recommended pedal distance, the front pedal starting angle and the rear pedal starting angle can be predicted according to the parameters of the different athletes, so that the training times and time for acquiring the optimal parameters are effectively reduced.

As shown in fig. 13, which is a starting block diagram of the present invention, a stress space coordinate system of the three-dimensional force sensor is established on the slope of the starting block, the direction along the slope is the X-axis direction, the direction perpendicular to the slope is the Z-axis direction, the direction parallel to the slope is the Y-axis direction, and the direction of the stress is the positive direction. Based on acting force and reactionThe principle of force, the resultant of the Z and X directions, is the main forward thrust the athlete receives with the help of the starting block. The greater the forward thrust the athlete receives, the greater the starting acceleration, from which it is known that F_xAnd F_zThe resultant force of (1) is the main force for generating the forward horizontal acceleration, so that whether the forward horizontal acceleration is beneficial to be obtained can be used as the reference basis for the starting mode, and the force F in the Y-axis direction_yIs the force that the athlete obtains by means of the starting block to maintain balance, the smaller the force lost tangentially, the easier the athlete can maintain balance.

During actual starting, although sprinting seeks this variable in horizontal velocity, the body of any person leaving the starting block tends to move obliquely upward or at an angle to the horizontal. The angle may be different depending on individual differences. Because of the angle with the horizontal plane, the force integration is decomposed into the integration in the horizontal and vertical directions. According to the law of conservation of momentum, it is possible to find a starting mode in which the greater the horizontal impulse forward of the person to be trained, the smaller the tangential force that keeps balance, and the shortest time for reaching the maximum force.

In order to measure the three-dimensional force of the athlete on the pedal, the pedal inclined plane is designed into a force measuring platform, and a three-dimensional force measuring sensor is arranged between the pedal inclined plane and the pedal body. The three-dimensional force transducer comprises an X-direction differential capacitance unit combination and a Y-direction differential capacitance unit combination, wherein the X-direction differential capacitance unit combination calculates the tangential force in the X direction and eliminates the influence of the tangential force in the Y direction through capacitance value subtraction, the Y-direction differential capacitance unit combination calculates the tangential force in the Y direction and eliminates the influence of the tangential force in the X direction through capacitance value subtraction, and the capacitance values of the X-direction differential capacitance unit combination and the Y-direction differential capacitance unit combination are summed to calculate the normal force of the capacitance transducer and eliminate the influence of the tangential force. The X-direction differential capacitance unit combination and the Y-direction differential capacitance unit combination respectively comprise more than two capacitance unit modules which mutually form a differential motion, and the capacitance unit modules are formed by more than two strip-shaped capacitance unitsAnd each strip-shaped capacitor unit comprises a driving electrode of an upper polar plate and an induction electrode of a lower polar plate. The width of the driving electrode and the width of the induction electrode of each strip-shaped capacitor unit are the same, the length of the driving electrode is greater than that of the induction electrode, and left difference positions delta are reserved at two ends of the length of the driving electrode respectively_{Left side of}And the right difference position delta_{Right side}，b_{0 drive}＝b_{Feeling of 0}+δ_{Right side}+δ_{Left side of}Wherein b is_{0 drive}Length of the driving electrode of the strip-shaped capacitor unit, b_{Feeling of 0}The length of the induction electrode of the strip-shaped capacitance unit. The difference delta_{Left side of}＝δ_{Right side}And is andwherein d is₀Is the thickness of the elastic medium, G is the shear modulus, τ, of the elastic medium_maxThe maximum stress value. The driving electrodes and the sensing electrodes of the strip-shaped capacitor units of the two groups of capacitor unit modules which mutually form the differential are provided with initial dislocation offsets along the width direction, and the dislocation offsets have the same size and opposite directions. The comb-shaped structure comprises more than 20 strip-shaped capacitor units and leads connected with the strip-shaped capacitor units in a one-to-one correspondence manner, and an electrode distance a is arranged between every two adjacent strip-shaped capacitor units_δ. The parallel plate area S ═ M (a)₀+a_δ)b₀Wherein, the number of the strip-shaped capacitor units is M, b₀Is the length of the strip-shaped capacitor unit, a₀The width of the strip-shaped capacitor unit. And the lead of each strip-shaped capacitor unit of the capacitor unit module is connected to the signal processor of the sensing system in parallel or independently. Width of the strip-shaped capacitor unitWherein d is₀E is the Young's modulus of the elastic medium, and G is the shear modulus of the elastic medium. An intermediate converter is arranged between the sensing system signal processor and the capacitance unit module and is used for setting the transmission coefficient of voltage to capacitance or frequency to capacitance.

1. Conversion characteristics of strip-shaped capacitor unit

(1) Excitation signal and coordinate system

The strip-shaped capacitor unit is arranged in a rectangular coordinate system shown in figure 1, and the length b of the plane of the polar plate is₀Width a₀Thickness d of elastic medium₀. Three-dimensional excitation is applied to the outer surface of the capacitor plate, and the generated contact type acting force has three directional components of Fx, Fy and Fz, the acting directions of the Fx and Fy are along the X axis and the Y axis, and the acting direction of the Fz is along the OZ axis, namelyThe direction, normal direction and tangential direction stress are both stress tensors, and the response of capacitance can be output from the lead wires of the electrodes; normal stress sigma_nFn/A, wherein A ═ a₀·b₀The pole plate is a normal force bearing surface, and Fn is a normal component; generating paired tangential stresses tau on both side surfaces_x＝Fx/A，τ_y＝Fy/A。

According to Hooke's law, σ, in elastic mechanics_nAnd τ_x，τ_yA corresponding deformation of the elastomer will occur. Wherein,

${\mathrm{\σ}}_n=E\·{\mathrm{\ϵ}}_n=E\·{\mathrm{\δ}}_n/d_0=\frac{F_n}{A}---\left(1\right)$

$\±{\mathrm{\τ}}_x=\±{\mathrm{\γ}}_x\·G=\±G\·{\mathrm{\δ}}_x/d_0=\±\frac{F_x}{A}---\left(2\right)$

$\±{\mathrm{\τ}}_y=\±{\mathrm{\γ}}_y\·G=\±G\·{\mathrm{\δ}}_y/d_0=\±\frac{F_y}{A}---\left(3\right)$

wherein E is the Young's modulus (unit: GN/m) of the elastic medium²) G is the shear modulus of the elastic medium (unit: GN/m²) δ n is the normal displacement of the elastic medium (unit: μ m), and δ x and δ y are relative offsets of the upper and lower plates of the strip-shaped capacitor cell (unit: μ m) whose signs are indicated by the coordinate axesAnd (4) determining.

(2) Capacitance formula and input-output characteristics thereof

The initial capacitance of a rectangular parallel plate capacitor is:

$C_0=\frac{{\mathrm{\ϵ}}_0\·{\mathrm{\ϵ}}_r\·a_0\·b_0}{d_0}---\left(4\right)$

in the formula, epsilon₀The electric constant of the vacuum medium is 8.85PF/m, epsilon_r2.5 is the relative permittivity of the dielectric. d₀Receive sigma_nIs excited to produce a relative deformation epsilon_n＝δ_n/d₀＝σ_nE, substituting into (4) to obtain input/output characteristics

$C_n={\mathrm{\ϵ}}_0\·{\mathrm{\ϵ}}_r\frac{a_0\·b_0}{d_0(1-{\mathrm{\ϵ}}_n)}={\mathrm{\ϵ}}_0\·{\mathrm{\ϵ}}_r\frac{a_0\·b_0}{d_0(1-\frac{F_n}{AE})}---\left(5\right)$

(3) Linearity and sensitivity under normal stress

a. Degree of normal linearity

In the formula (5), F_nIn the denominator, therefore C_n＝f(F_n) Is non-linear due to the maximum value σ in the conversion range_nmaxε compared with the dielectric elastic constant E_nIs a very small quantity, i.e. epsilon in the denominator_n<<1, expanding (5) according to a series and omitting high-order infinitesimal more than quadratic, wherein the formula (5) can be simplified as follows:

$C_n=C_0(1+\mathrm{\&epsiv;})=C_0(1+\frac{F_n}{A\&CenterDot;E})---\left(6\right)$

can be seen in C_nAnd F_nThe maximum relative error of the normal linearity in the conversion characteristic of (a) is close to zero.

b. Sensitivity of the probe

Definition of sensitivity by Normal

The linear sensitivity can be obtained according to the formula (6),

S_n1＝C₀/AE＝ε₀ε_r/d₀E(7)

and according to the formula (5)

$S_{n2}=\frac{{\mathrm{dC}}_n}{{\mathrm{dF}}_n}=C_0\&CenterDot;\frac{1}{1-2\mathrm{\&epsiv;}}=C_0\&CenterDot;\frac{1}{1-2\frac{F_n}{A\&CenterDot;E}}---\left(8\right)$

S_n2With F_nAnd is changed to F_nThe greater, S_n2The larger, the slightly non-linear over the entire conversion characteristic.

(4) Tangential stress tau_xAnd τ_yCapacitance change under excitation

Tangential stress tau_xAnd τ_yWithout changing the geometric parameters b of the plates₀And a₀To the thickness d of the medium₀Nor is it affected. However tau_xAnd τ_yThe spatial structure of the parallel plate capacitor is changed, and dislocation offset occurs between the upper and lower electrode plates facing in the forward direction. Taking OX direction as an example, the plate is at tau_xOffset delta under action_x。

In FIG. 2 when τ is_xIs zero, a_{0 is on}＝a_{0 is lower}Are aligned, effective cross-section A between the substrates_τ＝a₀·b₀(ii) a In FIG. 3, at τ_xUnder the action of the right direction, the upper polar plate generates right dislocation deviation delta relative to the lower polar plate_xSo as to make the effective area A between the upper and lower polar plates when calculating the capacitance_τ＝(a₀-δ_x)·b₀(ii) a In FIG. 4, when τ is_xIn the left direction, the misalignment is shifted by δ_xThen toLeft, and A_τ＝(a₀-δ_x)·b₀The reduction of the effective area is the same, and the capacitance thus produced is:

$C_{\mathrm{\&tau;}x}=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;(a_0-{\mathrm{\&delta;}}_x)\&CenterDot;b_0}{d_0}---\left(9\right)$

according to shearing Hooke's law

τ_x＝γ_x·G＝G·δ_x/d₀(10)

Substituting (10) into (9) to obtain

$C_{\mathrm{\&tau;}x}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;{\mathrm{\&delta;}}_x\&CenterDot;b_0}{d_0}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0{\mathrm{\&tau;}}_x}{G}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r{F}_x}{{\mathrm{Ga}}_0}---\left(11\right)$

(11) Formula is the input-output characteristic under shear stress, C_τAnd τ_xIn a linear relationship.

And its sensitivity

$S_{\mathrm{\&tau;}x}=\frac{{\mathrm{dC}}_{\mathrm{\&tau;}x}}{{\mathrm{dF}}_x}=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{{\mathrm{Ga}}_0}---\left(12\right)$

Analyses similar to equations (9) - (12) are equally applicable to τ_yAnd C_τyThe characteristic and technical index of (1) are merely long side b of the strip-shaped capacitor unit₀Should be arranged in the direction of the OX axis and its short side a₀In the OY direction.

(5) Introduction of differential capacitor unit

The structural variations of the capacitor shown in FIGS. 3 and 4 are only illustrative of the capacitance output and the tangential stress + - τ_xThe capacitance increment is negative in the input relation, so that the initial capacitance structure is not suitable for being used for +/-T_xA response of increasing or decreasing capacitance is obtained. Therefore, the invention adjusts the initial structure of the upper and lower electrode plates of the capacitor to form a pair of differential capacitance pairs (C)_LAnd C_R) As shown in detail in fig. 5.

In FIG. 5, a pair of capacitors C_LAnd C_RElectrode size a₀、b₀、d₀All are the same, initial misalignment offset δ₀Also the same, the difference being the left capacitor C_LUpper layer delta₀The point of the tip is pointed at + OX, and the capacitor C on the right_RUpper layer delta₀The sharp corners point to-OX.

When tau is_xWhen the content is equal to 0, the content,i.e. the capacitance corresponding to the shaded part of the figure, is as in-F on the basis thereof_xProducing delta under excitation_xThe error shift of (2) produces a capacitance increase and decrease effect as shown in fig. 6.

$C_L=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0\&CenterDot;(a_0-{\mathrm{\&delta;}}_0\&PlusMinus;{\mathrm{\&delta;}}_x)}{d_0}---\left(13\right)$

C in FIG. 6_LAnd C_RDifferential capacitor pair_xWill produce + -delta_xAnd. + -. Δ C_τIn response to (2).

δ₀Should be of a size thatDesirable delta₀By 10 μm, equation (11) can be modified

$C_{\mathrm{\&tau;}x}=C_{\mathrm{\&tau;}0}+\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{{\mathrm{Ga}}_0}{F}_x---\left(14\right)$

In the formula,the initial capacitance when the shear stress is zero, and the formula (14) is the shear stress input-output characteristic, C_τxAnd F_xIs a linear relationship, and the sensitivity thereof

2. Contact parallel plate capacitor design

(1) Planar design of parallel plate capacitor

See the electrode plan layout in fig. 7, 8 and 9, at a 10 x 10mm²The center of the substrate is divided into four quadrants I, II, III and IV by a cross, wherein the quadrants I and II are pairs tau_xDifferential capacitive cell combinations that respond, III, IVQuadrant is to tau_yA responsive differential capacitive cell combination. The peripheral line is 10X 10mm²The PCB substrate is precisely cut to ensure the precision of the shape and the size. The hatched part shows the cross section of the outer mold in the lost wax casting process, and the geometric shape and size of the outer mold should be kept accurate during mechanical forming, so that the outer mold is convenient to demould and can be assembled and disassembled, and the dimensional accuracy should be maintained, and finally, the mutual interference of three-dimensional force on the capacitance response is guaranteed to be eliminated.

The capacitor unit module adopts a comb-shaped structure consisting of more than two strip-shaped capacitor units, and each strip-shaped capacitor unit comprises a driving electrode of an upper polar plate and an induction electrode of a lower polar plate. From the formula (12) a₀The smaller the sensitivity of the tangential stress response, the greater the single capacitor is, and the longer the single capacitor is. Let each strip-shaped capacitor unit have a width₀The width of the groove between two strip-shaped capacitor units is a_δThe pitch of each strip-shaped capacitor unit is a₀+a_δ. In order to fully utilize the planar space of the square substrate, M (a)₀+a_δ)b₀Approximately equal to 1 square substrate surface area, M is the number of strip-shaped capacitor units in 4 quadrants, then M (a)₀+a_δ) 2 x 10mm, wherein the groove width a_δIt should not be too large, otherwise it is not favorable to use the effective planar space on the substrate, and it should not be too small, and it should be constrained by the lost wax casting process. For normal sensitivity S_nAnd tangential sensitivity S_τSimilarly, let a be according to equations (7) and (12)₀·G＝d₀E, when d₀When the thickness is 0.1mm, a is₀0.15mm, if a_δAnd when the width is 0.05mm, the width M is 100, and each image has 25 strip-shaped capacitor units.

To realize tau_xAnd τ_yTangential response does not mutually influence, and delta is reserved at two ends of the length of the driving electrode₀Thus b is_{0 drive}＝b_{0 bottom}+2·δ₀Wherein in b_{0 drive}The length reservation of the two ends should be ensured theoreticallyCalculated value thereof is Therefore, it should be ensured in terms of process b_{0 drive}－b_{0 bottom}≥0.01mm。

To realize tau_xAnd τ_yThe normal capacitance response is not affected, certain dislocation offset is guaranteed in the planar arrangement of the driving electrodes and the sensing electrodes of each strip-shaped capacitance unit in each quadrant, the influence is eliminated through differential motion, the positions of the sensing electrodes on the lower-layer PCB substrate are taken as references, and the arrangement of the driving electrodes on the upper-layer PCB substrate is based on the edge lines of the PCB substrate. The four dotted boxes in the figure are references of the sensing electrode on the lower plate. The differences between them and the geometric datum line are delta₀(0.1mm) to ensure τ_xDifferential capacitance output response is generated in I and II quadrant capacitance units, and the output response is generated in III and IV quadrant capacitance units_ySetting an initial misalignment offset delta_xoThe value of which should be guaranteedCalculated value and delta thereof₀Similarly, their initial misalignment offsets are all set at δ_xo＝δ_yo0.01mm to ensure that the capacitor cells in the four quadrants are at τ_xAnd τ_yTwo groups of differential capacitance pairs can be generated under tangential excitation. Thus ensuring tau already when calculating the normal capacitance output response_xAnd τ_yWithout any effect on the normal capacitance response. In FIG. 6C_τxI＝C_RAnd C_τxII＝C_LTo convert tau_xDifferential capacitor pair of, and C_τxIII＝C_LAnd C_τxIV＝C_RIs to convert tau_yThe differential capacitor pair of (1).

(2) Normal stress calculation

The normal response capacitance of a single capacitor can be rewritten by equation (6)

$C_{ni}=N(C_0+\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;Fn}{d_{0}E})---\left(15\right)$

In each quadrant, N refers to the number of strip-shaped capacitor units in one quadrant, and N strip-shaped capacitor units are connected in parallel.

If they are then summed, it is obtained

The above formula is sigma_nThe total response of the capacitance of (c).

Although the summation of the individual capacitances can be achieved by a parallel connection of the electrode leads. Once connected, however, the difference combining can no longer be achieved, so the actual sum combining needs to be summed again via the outputs of the intermediate converters, see fig. 10, and in the signal flow diagram of the summation, the intermediate converter K can be the voltage-to-capacitance or frequency-to-capacitance transmission coefficient, thereby completing the synthesis of the normal response.

$O_n=4KN(C_0+\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;Fn}{d_{0}E})---\left(16\right)$

(3) Tangential stress calculation

C_ⅠTo C_ⅡAnd C_ⅢTo C_ⅣTwo pairs of differential combinations can be implemented, see FIG. 11, with differential processing, the total response of the differential outputs

$O_{\mathrm{\&tau;}x}=\frac{2{\mathrm{NK\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{a_{0}G}{F}_x---\left(17\right)$

In the above formula, either the normal excitation F_nOr tangential excitation F_yAll are not to O_τxAn influence is produced. I.e. automatically eliminating sigma_nAnd τ_yFor tau_xBecause the equivalent and congruent capacitance changes are automatically eliminated in all operations where the signals contain a subtraction. And F_yAnd F_xTo sigma_nCan pass through the upper electrode at b₀Direction increased geometric length 2 delta₀Elimination of O_τyThe same process can be used.

(4) Choice of main material and its characteristic parameters

The cross-sectional view of the structure of the comb-shaped parallel plate capacitor is similar to the sandwich structure shown in FIG. 12. In fig. 12, 1 is an upper PCB substrate, 2 is a lower PCB substrate, 3 is a driving electrode, 4 is a sensing electrode, and 5 is an elastic medium.

Distance d between the plates₀The inner spaces of the upper and lower substrates except for the copper foil electrodes were all PDMS (polydimethylsiloxane) super-elastic insulating media filled by a lost wax casting method, which was 0.1 mm. Its mechanical and physical parameters are Young's modulus E equal to 6.2MPa, shear elastic modulus G equal to 4.1MPa, and relative dielectric constant epsilon of medium polarization_γ2.5. Since E and G of the medium are much smaller than the elastic modulus E of copper_{Copper (Cu)}103 GPa. Therefore, the deformation of the internal medium of the capacitor in a stress state is far larger than that of the polar plate.

(5) Electrode lead design

Both the driving electrodes and the sensing electrodes need to be provided with lead-out wires, and considering that each driving electrode is grounded on a signal level, four groups of driving electrodes only need to share one lead-out wire. And the four capacitor unit module sensing electrodes need to use independent outgoing lines, so that the whole capacitor assembly has at least 5 pins which are led out from the side surface of the planar package, and the outer surfaces of the top and the bottom of the whole assembly can be conveniently contacted with a measuring object.

The invention completes the design of a novel three-dimensional force-sensitive capacitor combination under the support of a new material and a new process, and the design is 10 multiplied by 10mm²The stress surface can transmit the stress to the medium more uniformly in the normal direction or the tangential direction. The four unit capacitors are distributed in two pairs. In the contact of space force and the sensor surface, the external force is only 1, the capacitance response is 4, and the normal direction F can be obtained by summing the 4 capacitances_nInformation of (2), i.e. the whole electrode plate is aimed at F_nMake contribution, at the same time two pairs of capacitors are combined to form differential system, and F can be obtained_xAnd F_yThereby completely describing a three-dimensional force.

The invention has been described above with reference to the accompanying drawings, it is obvious that the invention is not limited to the specific implementation in the above-described manner, and it is within the scope of the invention to apply the inventive concept and solution to other applications without substantial modification. The protection scope of the present invention shall be subject to the protection scope defined by the claims.

Claims (10)

1. The sprint training assisting device is characterized by comprising a three-dimensional force measuring starting device, gait recognition units and a sensing system signal processor, wherein pedal distance acquisition units and starting angle acquisition units are respectively arranged on a front pedal and a rear pedal of the three-dimensional force measuring starting device, three-dimensional force pressure sensors for receiving plantar pressure information are respectively arranged on stress inclined planes of the front pedal and the rear pedal, the pressure sensors transmit acquired signals to the sensing system signal processor, and the gait recognition units which are in wireless connection with the sensing system signal processor comprise sole pressure sensors and a wireless communication unit which are arranged in a shoe interlayer.

2. The sprinting aid training device according to claim 1, wherein the plantar pressure sensors are provided in five sets per foot, three sets are provided at the forefoot of the midsole for measuring the reaction force of the pedals against the foot, and two sets are provided at the toe portion of the midsole for measuring the reaction force of the ground against the foot.

3. The sprint training aid as claimed in claim 1, wherein the sensing system signal processor includes a signal conversion and amplification unit, a data processing unit and a controller connected in sequence, the controller is configured to receive data output by the data processing unit, analyze and calculate the data to determine the optimal data of the sprint training index, the data processing unit includes a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, the data filtering unit is configured to filter error data collected by the sensor, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data of the data classifying unit to output a two-dimensional data table, and the database is configured to store detected data and standard data.

4. A sprint training aid as claimed in claim 1 wherein the sensing system signal processor further includes an information input unit including sprinter information including height, weight, leg and foot metrics.

5. The sprint training aid of claim 1, wherein the three-dimensional force pressure sensor includes an X-direction differential capacitance unit combination and a Y-direction differential capacitance unit combination, each of the X-direction differential capacitance unit combination and the Y-direction differential capacitance unit combination includes two or more capacitance unit modules forming a differential function with each other, the capacitance unit modules adopt a comb structure composed of two or more strip-shaped capacitance units, each strip-shaped capacitance unit includes a driving electrode of an upper plate and a sensing electrode of a lower plate, and a sum of capacitance values of the X-direction differential capacitance unit combination and the Y-direction differential capacitance unit combination calculates a normal force of the capacitance sensor and eliminates an influence of a tangential force.

6. The sprinting training aid according to claim 5, wherein the width of the driving electrode and the width of the sensing electrode of each strip-shaped capacitor unit are the same, the length of the driving electrode is greater than the length of the sensing electrode, and a left difference delta is reserved at each end of the length of the driving electrode_{Left side of}And the right difference position delta_{Right side}，b_{0 drive}＝b_{Feeling of 0}+δ_{Right side}+δ_{Left side of}Wherein b is_{0 drive}Length of the driving electrode of the strip-shaped capacitor unit, b_{Feeling of 0}The length of the induction electrode of the strip-shaped capacitor unit is delta_{Left side of}＝δ_{Right side}And is andwherein d is₀Is the thickness of the elastic medium, G is the shear modulus, τ, of the elastic medium_maxThe maximum stress value.

7. The sprint training aid of claim 5, wherein the driving electrodes and the sensing electrodes of the two sets of strip-shaped capacitor units forming the differential capacitor unit module are provided with an initial offset along the width direction, and the offset is the same and opposite.

8. The sprinting auxiliary training device according to claim 5, wherein the comb-shaped structure comprises more than 20 strip-shaped capacitor units, leads connected with the strip-shaped capacitor units in a one-to-one correspondence manner, and an electrode distance a is provided between two adjacent strip-shaped capacitor units_δThe parallel plate area S ═ M (a)₀+a_δ)b₀Wherein M is the number of the strip-shaped capacitor units, b₀Is the length of the strip-shaped capacitor unit, a₀Strip capacitor sheetAnd the leads of each strip-shaped capacitor unit of the capacitor unit module are connected to a sensing system signal processor in parallel or independently.

9. Sprinting assisted exercise equipment according to claim 5, wherein the width of the strip capacitor unitWherein d is₀E is the Young's modulus of the elastic medium, and G is the shear modulus of the elastic medium.

10. The sprinting training aid according to claim 5, wherein an intermediate transformer is provided between the sensing system signal processor and the capacitive unit module, the intermediate transformer being configured to set a voltage to capacitance or frequency to capacitance transmission coefficient.