CN204815616U - Act on force measuring device in dash between sole and race starter - Google Patents

Abstract

The utility model relates to an act on force measuring device in dash between sole and race starter, 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 trainer is assisted in the dash, and prorsad horizontal motive force, used time and the equilibrant of maxmizing power are taken all factors into consideration to the atress process of real -time measurement sportsman race starter when the start of a race to obtain the off posture of the best.

Description

Device for measuring acting force between sole and starting device in sprinting

Technical Field

The utility model belongs to the technical field of the supplementary training of motion, involve the sprint motion, concretely relates to sole and starting device inter-force measuring device in sprint.

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.

SUMMERY OF THE UTILITY MODEL

In order to overcome the not enough of prior art, the utility model provides a measuring device of acting force between sole and starting device in sprint arranges the sensor of gathering plantar pressure information on the atress inclined plane of starting pedal, and through the analysis to pressure data, according to momentum conservation law, can find to make the horizontal driving force that the person of being trained is forward big more, and the tangential force of keep balance is minimum, is used for reaching the shortest mode of starting running of maximum power time simultaneously.

The technical scheme of the utility model is that: the utility model discloses a measuring device of acting force between sole and starting device in sprinting, including three-dimensional dynamometry starting device, gait recognition unit, sensing system signal processor, the preceding footboard of three-dimensional dynamometry starting device, be equipped with footboard interval acquisition unit on the back footboard respectively, start angle acquisition unit, the footboard in the front, the three-dimensional force pressure sensor who accepts plantar pressure information has all been arranged on the atress inclined plane of back footboard, pressure sensor gives sensing system signal processor with the signal transmission who gathers, with sensing system signal processor wireless connection's gait recognition unit including setting up in interbedded sole pressure sensor and wireless communication unit. 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.

Above-mentioned pressure sensor includes ring electric capacity unit group and strip electric capacity unit group, strip electric capacity unit group sets up the four corners at ring electric capacity unit group outer base plate, and ring electric capacity unit group includes that ring electric capacity unit is right more than two pairs, ring electric capacity unit is right including two ring electric capacity units, strip electric capacity unit group includes X direction differential electric capacity unit group and Y direction differential electric capacity unit group, and X direction differential electric capacity unit group and Y direction differential electric capacity unit group all include the differential electric capacity unit module of mutual formation more than two, the electric capacity unit module is the broach structure of constituteing by the strip electric capacity unit more than two, and every ring electric capacity unit and strip electric capacity unit all include the drive electrode of upper polar plate and the response electrode of lower polar plate.

The utility model discloses acting force measuring device between sole and starting block in dash, every ring electric capacity unit's response electrode is just the same with the drive electrode and shape, every strip electric capacity unit's drive electrode is the same with response electrode width, and strip electric capacity unit's drive electrode length is greater than response electrode length, and left difference delta is reserved respectively at strip electric capacity unit's drive electrode length both ends_{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. Left difference position delta of the strip-shaped capacitor unit_{Left side of}Right difference delta_{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 ring capacitor unit group comprises n concentric ring capacitor unitsWherein, a_{Flat plate}Length of parallel plate, r_{Round (T-shaped)}Is the width of the ring capacitor unit, a_{Delta circle}And the electrode distance between two adjacent circular capacitor units. The X-direction differential capacitance unit group and the Y-direction differential capacitance unit group both comprise m strip-shaped capacitance units,wherein, a_{Flat plate}Length of parallel plate, a_{Delta bar}Is the electrode spacing between two adjacent strip-shaped capacitor units, a₀The width of the strip-shaped capacitor unit. The width r of the concentric ring capacitor unit_{Round (T-shaped)}And the width a of the strip-shaped capacitor unit₀Equal; electrode spacing a of strip-shaped capacitor unit_{Delta bar}And the electrode spacing a of the circular ring capacitor unit_{Delta circle}Equal, 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. The drive electrodes of the ring capacitor unit group and the strip capacitor unit group are connected with a sensing system signal processor through an outgoing line, the induction electrode of each ring capacitor unit of the ring capacitor unit group is connected with the sensing system signal processor through an independent lead, and the induction electrodes of the capacitor unit modules of the X-direction differential capacitor unit group and the Y-direction differential capacitor unit group are respectively connected with a sensing system signal position through an outgoing lineAnd (4) connecting the processors. Intermediate converters are respectively arranged among the ring capacitor units, the capacitor unit modules and the sensing system signal processor and are used for setting transmission coefficients of voltage to capacitance or frequency to capacitance.

The utility model discloses there is following positive effect: the utility model discloses a training device is assisted in sprint, the atress process of real-time measurement sportsman starting device when the race, the horizontal push force that considers forward, reach the used time of maximum power and balancing force are synthesized to obtain the best posture of starting. Additionally, the utility model discloses a normal force and tangential force can be measured simultaneously to the sensor, and sensitivity is high, and the polar plate utilization efficiency is high, and whole ring electric capacity unit group all makes contributions to the normal force, has better dynamic behavior.

Drawings

Fig. 1 is an area analysis diagram of the offset and dislocation of concentric rings according to the embodiment of the present invention.

Fig. 2 is an analysis diagram of the dislocation of the outer concentric rings to the outer diameter circle according to the embodiment of the present invention.

Fig. 3 is a plan view of a parallel plate capacitor according to an embodiment of the present invention.

Fig. 4 is a structural diagram of a drive electrode according to an embodiment of the present invention.

Fig. 5 is a rectangular coordinate system of the flat capacitor plate according to the embodiment of the present invention.

Fig. 6 is a structural diagram of two sets of circular capacitor sets according to an embodiment of the present invention.

Fig. 7 is an initial misalignment map of a differential strip capacitor cell according to an embodiment of the present invention.

Fig. 8 is a diagram illustrating the deviation of the differential strip-shaped capacitor unit after being stressed according to the embodiment of the present invention.

Fig. 9 is a schematic signal differential diagram of a unit capacitor pair according to an embodiment of the present invention.

Fig. 10 is a cross-sectional structure of a parallel plate capacitor according to an embodiment of the present invention.

Fig. 11 is a starting block diagram according to 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 explain the embodiments of the present invention in further detail, such as the shapes and structures of the components, the mutual positions and connection relationships among the components, the functions and working principles of the components, the manufacturing process, and the operation and use method, etc., so as to help those skilled in the art to understand the concept and technical solutions of the present invention more completely, accurately and deeply.

The utility model discloses a main thinking is: 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 measuring device of acting force between sole and starting device in sprinting, including three-dimensional dynamometry starting device, gait recognition unit, sensing system signal processor, be equipped with footboard interval acquisition unit on the preceding footboard of three-dimensional dynamometry starting device, the back footboard respectively, 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 to sensing system signal processor, the 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.

The footboard start angle and back footboard start angle before prior art data acquisition only gathers, the utility model discloses the sole footboard reaction force and the reaction force on ground of gathering sole pressure sensor collection simultaneously to fuse the processing to data, further promote the intentional effect, different sportsman's parameter information draws forth different data curve graphs respectively simultaneously, and can predict its recommended footboard interval according to different sportsman's parameter, preceding footboard start angle and back footboard start angle, effectively reduce the training number of times and the time that obtains optimum parameter like this.

As shown in fig. 11, for the starting block diagram of the utility model, on the starting block inclined plane, the stress space coordinate system of the three-dimensional force sensor is established, and the direction is the X axis direction along the inclined plane downward direction, and the perpendicular to inclined plane direction is the Z axis direction, and the direction parallel with the inclined plane level is the Y axis direction, and the direction of getting the stress is the positive direction. Based on the principle of acting and reacting forces, the resultant force of the Z and X directions is the main forward thrust that the athlete obtains 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 is inclinedThe pedal is designed into a force measuring platform, and a three-dimensional force sensor is arranged between the inclined plane of the pedal and the pedal body. Following detail the utility model discloses a three-dimensional force transducer's measurement principle: the sensor comprises a ring capacitor unit group and a strip capacitor unit group, wherein the ring capacitor unit group is used for measuring the tangential force and the normal force, the strip capacitor unit group is used for measuring the direction of the tangential force, and the strip capacitor unit group is arranged at four corners outside the substrate ring capacitor unit group. The ring electric capacity unit group includes that ring electric capacity unit is right more than two sets of, ring electric capacity unit is right including two ring electric capacity units, strip electric capacity unit group includes X direction differential electric capacity unit group and Y direction differential electric capacity unit group, and X direction differential electric capacity unit group and Y direction differential electric capacity unit group all include the differential electric capacity unit module of mutual formation more than two, the electric capacity unit module adopts the broach structure of constituteing by the strip electric capacity unit more than two, and every ring electric capacity unit and strip electric capacity unit all include the drive electrode of upper polar plate and the induction electrode of bottom plate. The induction electrode and the driving electrode of each circular ring capacitor unit are opposite and same in shape, the driving electrode and the induction electrode of each strip capacitor unit are same in width, the length of the driving electrode of each strip capacitor unit is larger than that of the induction electrode, and left difference delta is reserved at two ends of the length of the driving electrode of each strip capacitor unit_{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. Left difference position delta of the strip-shaped capacitor unit_{Left side of}Right difference delta_{Right side}And is andwherein d is₀Is the thickness of the medium, G is the shear modulus, τ, of the elastic medium_ymaxThe 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 ring capacitor unit groupComprising n concentric rings of capacitor cells, whereinWherein, a_{Flat plate}Length of parallel plate, r_{Round (T-shaped)}Is the width of the ring capacitor unit, a_{Delta circle}And the electrode distance between two adjacent circular capacitor capacitors. The capacitor unit module adopts a comb-tooth structure, the X-direction differential capacitor unit group and the Y-direction differential capacitor unit group both comprise m strip-shaped capacitor units, wherein, a_{Flat plate}Length of parallel plate, a_{Delta bar}Is the electrode spacing between two adjacent strip-shaped capacitor units, a₀The width of the strip-shaped capacitor unit. The width r of the concentric ring capacitor unit_{Round (T-shaped)}And the width a of the strip-shaped capacitor unit₀Equal; electrode spacing a of strip-shaped capacitor unit_{Delta bar}And the electrode spacing a of the circular ring capacitor unit_{Delta circle}Equal, 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. The drive electrodes of the ring capacitor unit group and the strip capacitor unit group are connected with the sensing system signal processor through an outgoing line, the induction electrode independent lead of each ring capacitor unit of the ring capacitor unit group is connected with the sensing system signal processor, and the induction electrodes of the capacitor unit modules of the X-direction differential capacitor unit group and the Y-direction differential capacitor unit group are respectively led out through an outgoing line and connected with the sensing system signal processor. Intermediate converters are respectively arranged among the ring capacitor units, the capacitor unit modules and the sensing system signal processor and are used for setting transmission coefficients of voltage or frequency to the capacitors.

The derivation and principle of the present invention, the shape, structure, mutual position and connection relationship between the parts, the function and operation principle of the parts, the manufacturing process and operation method, etc. will be described in further detail with reference to fig. 1-10.

1.1 capacitance formula and input-output characteristics thereof

The initial capacitance of the parallel plates is:

$C_0=\frac{{\mathrm{\ϵ}}_0\·{\mathrm{\ϵ}}_r\·A_0}{d_0}---\left(1\right)$

in the formula, epsilon₀The electric constant of the vacuum medium is 8.85PF/m, epsilon_r2.5 is the relative permittivity of the dielectric, a₀The initial facing area of the upper and lower polar plates. d₀Receive sigma_nIs excited to produce a relative deformation epsilon_n＝δ_n/d₀＝σ_nAnd E, substituting the formula (1) to obtain the input-output characteristics

$C_n={\mathrm{\ϵ}}_0\·{\mathrm{\ϵ}}_r\frac{A_0}{d_0(1-{\mathrm{\ϵ}}_n)}={\mathrm{\ϵ}}_0\·{\mathrm{\ϵ}}_r\frac{A_0}{d_0(1-\frac{F_n}{AE})}---\left(2\right)$

1.2 Linearity and sensitivity under Normal stress

1.2.1 Normal Linearity

(2) In the formula F_nIn the denominator, therefore C_n＝f(F_n) The relationship of (a) is non-linear. Maximum value sigma in the range of conversion_nmaxε compared with the dielectric elastic constant E_nIs a very small quantity, i.e. epsilon in the denominator_n<<1, expanding the formula (2) according to a series, and omitting high-order infinitesimal more than the square, which can be simplified as follows:

$C_n=C_0(1+\mathrm{\&epsiv;})=C_0(1+\frac{F_n}{A\&CenterDot;E})---\left(3\right)$

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.

1.2.2 sensitivity

Definition of sensitivity by Normal

According to the formula (2)

$S_{n2}=\frac{{\mathrm{dC}}_n}{{\mathrm{dF}}_n}=C_0\&CenterDot;\frac{1}{1-2\mathrm{\&epsiv;}}=C_0\&CenterDot;\frac{1}{1-2\frac{F_n}{A\&CenterDot;E}}---\left(4\right)$

The linear sensitivity can be obtained according to the formula (3),

S_n1＝C₀/AE＝ε₀ε_r/d₀E(5)

S_n2with F_nAnd is changed to F_nThe greater, S_n2The larger, the slightly non-linear over the entire conversion characteristic.

1.3 relationship between tangential displacement and effective area of circular ring capacitor

Analysis was performed for concentric ring capacitance pairs, as shown in FIG. 1, R₁Is the outer radius of the circle, R₂The radius of the inner circle, R equals the width of the ring, and equals the radius of the large outer circle R₁Inner circle radius R₂. Force F on a section of the drive electrode_xCausing a shear dislocation between the corresponding driving and sensing electrodes, and d_xThe displacement of the tangent plane and the dislocation area are S_{Inner part}And S_{Outer cover}The initial facing area of the electrode plate should be pi (R)₁ ²-R₂ ²). FIG. 2 is an analysis graph of capacitance of outer concentric ring versus outer diameter circle, where the distance between the centers of the two circles is d_xThe intersection point of the two circle centers and the two circles forms a rhombus before and after moving, and S can be calculated_{Outer cover}Area of (d):

in the above formula, there is d_x<<R₁To thereby obtain

By

Will be provided withAnd the high-order terms are omitted,

similarly, it can be known that S_{Inner part}＝2R₂d_xTherefore, the error area of the concentric ring capacitor is S-2R₁d_x+2R₂d_x。

1.4 capacitance Change of the Ring capacitive cell group under tangential stress τ excitation

The tangential stress tau does not change the geometric size parameter A of the polar plate₀To 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. Dislocation deviation d of polar plate under action of tau_x. When tau is zero, the upper and lower electrodes of the circular ring capacitor unit are opposite, and the effective section between the upper and lower electrodesIn FIG. 2, at τ_xUnder the action of right direction, the upper polar plate is displaced to right relative to the lower polar plate_xThereby the effective area between the upper and lower polar plates is calculated when the capacitance is calculatedThe resulting capacitance is:

$C_{\mathrm{\&tau;}x}=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;\left({\mathrm{\&pi;R}}_1^2-{\mathrm{\&pi;R}}_2^2-2R_1{d}_x-2R_2{d}_x\right)}{d_0}---\left(6\right)$

according to shear Hooke's law

τ_x＝γ_x·G＝G·δ_x/d₀(7)

Substituting (7) into (6) to obtain

$C_{\mathrm{\&tau;}x}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;2\left(R_1+R_2\right)d_x}{d_0}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;2\left(R_1+R_2\right)F_x}{A_{\mathrm{\&tau;}}G}=C_0-\frac{2{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r{F}_x}{G\mathrm{\&pi;}\left(R_1-R_2\right)}---\left(8\right)$

(8) The formula is the input-output characteristic under shear stress, C_τAnd τ_xIn a linear relationship, its sensitivity

$S_{\mathrm{\&tau;}x}=\frac{{\mathrm{dC}}_{\mathrm{\&tau;}}}{{\mathrm{dF}}_x}=\frac{2{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{G\mathrm{\&pi;}\left(R_1-R_2\right)}---\left(9\right)$

From equation (9), the tangential sensitivity and R can be seen₁-R₂In relation to this, the tangential sensitivity is inversely proportional to the width of the ring, the smaller the width the higher the sensitivity.

Design of 2-plate capacitor

2.1 design of Flat capacitors

See the electrode plan layout in FIG. 3 and the block diagram of the drive electrode in FIG. 4, at a 10X 10mm thickness²The circular ring type contact parallel plate three-dimensional pressure sensor on the substrate comprises a circular ring capacitance unit group and a strip-shaped capacitance unit group, wherein the circular ring capacitance unit group is used for measuring the tangential force and the normal force, the strip-shaped capacitance unit group is used for measuring the direction of the tangential force, and the strip-shaped capacitance unit group is arranged at four corners outside the circular ring capacitance unit group of the substrate. Therefore, the area of the parallel plates can be effectively used, the circular capacitor unit group is paved on the whole parallel plate, the circular capacitor unit group plays a role in measuring the three-dimensional force, and the strip-shaped capacitor unit group effectively utilizes the space at four corners of the parallel plate after the circular capacitor unit group is paved, and is used for measuring the direction of the three-dimensional force tangential force. The driving electrode and the induction electrode of the circular ring capacitor unit group are both composed of n concentric circular rings, and n is an even number, so that an n/2 circular ring capacitor unit pair is formed. The hatched portions represent the outer mold sections of the lost wax casting process, which geometry and dimensions should also be precise during mechanical forming.

Referring to the rectangular coordinate system of the plate capacitor of fig. 5, the origin of the coordinate system is at the origin of the concentric circles of the circular capacitor unit groups, the X-axis and the y-axis are along the diagonal directions of the plate capacitor, the X-direction differential capacitor unit group includes an X-direction differential capacitor unit group i and an X-direction differential capacitor unit group iii, and the X-direction differential capacitor unit group i and the X-direction differential capacitor unit group iii are along the diagonal directions of the plate capacitor, respectivelyThe Y-direction differential capacitor unit group II and the Y-direction differential capacitor unit group IV are respectively positioned on the positive half shaft and the negative half shaft of the Y-axis and are symmetrical along the X-axis, and the X-direction differential capacitor unit group I and the X-direction differential capacitor unit group III form a pair tau_xThe differential capacitor unit group II and the differential capacitor unit group IV form a pair tau_yA responsive differential capacitive cell combination.

The ring capacitor unit group comprises n concentric ring capacitor unitsWherein, a_{Flat plate}Length of parallel plate, r_{Round (T-shaped)}Is the width of the ring capacitor unit, a_δThe electrode distance between two adjacent circular ring capacitor capacitors. The capacitor unit module adopts a comb-tooth structure, the X-direction differential capacitor unit group and the Y-direction differential capacitor unit group both comprise m strip-shaped capacitor units,wherein, a_{Delta bar}An electrode distance a is arranged between two adjacent strip-shaped capacitor units₀The width of the strip-shaped capacitor unit. Width r of concentric ring capacitor unit_{Round (T-shaped)}And the width a of the strip-shaped capacitor unit₀Equal; electrode spacing a of strip-shaped capacitor unit_{Delta bar}And the distance a between the electrodes of the circular capacitor_{Delta circle}Equal, 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.

2.2 excitation Signal and coordinate System

Placing the circular capacitor unit in a rectangular coordinate system as shown in FIG. 5, three-dimensional excitation is applied to the outer surface of the capacitor plateThe contact force generated by the surface 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 axisThe 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, whereinThe pole plate is a normal force bearing surface, and Fn is a normal component; generating paired tangential stresses tau on both side surfaces_{Cutting machine}＝F_{Cutting machine}/A。

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

${\mathrm{\&sigma;}}_n=E\&CenterDot;{\mathrm{\&epsiv;}}_n=E\&CenterDot;{\mathrm{\&delta;}}_n/d_0=\frac{F_n}{A}$

wherein E is the Young's modulus GN/m of the elastic medium²G is the shear modulus GN/m of the elastic medium²δ n is the normal displacement (unit: mum) of the elastic medium, and δ x and δ y are the relative positions of the upper and lower plates of the circular ring capacitor unitThe offset (unit: μm) has a sign determined by the orientation of the coordinate axis.

2.3 calculation of Normal and tangential force magnitudes

And selecting the nth ring capacitor unit and the nth/2 ring capacitor unit, and calculating a composition equation set by establishing the ring capacitor units, as shown in fig. 6. After the electrode plate is subjected to normal and tangential excitation, the output capacitance of the nth circular ring capacitance unit is set as C₁N/2 ring capacitor units with output capacitance of C₂Tangential displacement of d_xNormal capacitance pole distance of d_n，S₁₀Is the initial facing area of the outer ring, S₂₀Is the initial facing area of the inner ring.

$C_1=\frac{\mathrm{\&epsiv;}\left(S_{10}-S1\right)}{d_n}=\frac{\mathrm{\&epsiv;}\left({\mathrm{\&pi;R}}_1^2-{\mathrm{\&pi;R}}_2^2\right)}{d_n}-\frac{\mathrm{\&epsiv;}\left(2R_1{d}_x+2R_2{d}_x\right)}{d_n}$ ①

$C_2=\frac{\mathrm{\&epsiv;}\left(S_{20}-S2\right)}{d_n}=\frac{\mathrm{\&epsiv;}\left({\mathrm{\&pi;r}}_1^2-{\mathrm{\&pi;r}}_2^2\right)}{d_n}-\frac{\mathrm{\&epsiv;}\left(2r_1{d}_x+2r_2{d}_x\right)}{d_n}$ ②

Will be provided withObtaining:

$C_1-C_2*\frac{R_1+R_2}{r_1+r_2}==\frac{\mathrm{\&epsiv;}\mathrm{\&pi;}\left(R_1^2-R_2^2\right)}{d_n}-\frac{R_1+R_2}{r_1+r_2}*\frac{\mathrm{\&epsiv;}\mathrm{\&pi;}\left(r_1^2-r_2^2\right)}{d_n}$

in the above formula $\frac{R_1+R_2}{r_1+r_2}=K,$ Then $d_n=\frac{\mathrm{\&epsiv;}\left(S_{10}-{\mathrm{KS}}_{20}\right)}{C_1-{\mathrm{KC}}_2}$

According to $d_n=d_0-\mathrm{\&Delta;}d=d_0(1-\frac{F_n}{E\&CenterDot;S_0})$

Therefore, the following steps are carried out: $F_n=\frac{\left(d_n-d_0\right)E\&CenterDot;S_0}{d_0}$

will be described in the above₂-②*C₁Obtaining:

$d_x=\frac{C_2{S}_{10}-C_1{S}_{20}}{2C_2\left(R_1+R_2\right)-2C_1\left(r_1+r_2\right)};$

by $\mathrm{\&gamma;}=\frac{\mathrm{\&tau;}}{G}=\frac{F_{\mathrm{\&tau;}}}{G\&CenterDot;S_0}=\frac{d_x}{d_0}=\frac{C_2{S}_{10}-C_1{S}_{20}}{d_{0}2C_2\left(R_1+R_2\right)-d_{0}2C_1\left(r_1+r_2\right)},$ So F_τIs composed of

$F_{\mathrm{\&tau;}}=\frac{\left(C_2{S}_{10}-C_1{S}_{20}\right)\&CenterDot;G\&CenterDot;S_0}{d_{0}2C_2\left(R_1+R_2\right)-d_{0}2C_1\left(r_1+r_2\right)}$

2.4 determination of the direction of tangential force

2.4.1 strip-shaped capacitor unit group structure and parameter design

To realize tau_xAnd τ_yThe tangential responses do not mutually influence, and the difference delta is reserved at the 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 ${10}^{-5}\&times;\frac{70\&times;{10}^3}{2.4\&times;{10}^6}=2.9\&times;{10}^{-8}m={10}^{-2}um<<1um,$ Therefore, it should be ensured in terms of process b_{0 drive}－b_{0 bottom}Not less than 0.01 mm. To realize tau_xAnd τ_yThe normal capacitance response is not influenced, and the driving electrode and the sensing electrode of each strip-shaped capacitance unit are arranged on the plane and are provided with certain dislocation offset, so that the mutual influence is eliminated through differential motion.

As shown in fig. 4, four dotted line boxes in the figure are taken as the reference of the sensing electrode on the lower plate, and the position of the sensing electrode on the lower PCB substrate is taken as a reference, then the arrangement of the driving electrode on the upper PCB substrate should be taken as the reference of the edge line of the PCB substrate. Each strip-shaped capacitor unit comprises a driving electrode of an upper polar plate and an induction electrode of a lower polar plate, and the width of each strip-shaped capacitor unit is set to be a₀The width of the groove between two strip-shaped capacitor units is a_δThe pitch of each strip-shaped capacitor unit is a₀+a_δ. Thus ensuring tau already when calculating the normal capacitance output response_xAnd τ_yThe normal capacitance response is not affected. The differences between them and the geometric datum line are delta₀(0.1mm) to ensure that the X-direction differential capacitance unit group I and the X-direction differential capacitance unit group III only generate a pair tau_xThe Y-direction differential capacitance unit group II and the Y-direction differential capacitance unit group IV only generate a pair tau_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 four capacitor units are at tau_xAnd τ_yTwo groups of differential capacitance pairs can be generated under tangential excitation.

In FIG. 7, 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. On the basis thereof, e.g. in-F_xProducing delta under excitation_xThe misalignment of (2) causes a capacitance increase and decrease effect as shown in FIG. 8,

$C_L=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0\&CenterDot;(a_0-{\mathrm{\&delta;}}_0\&PlusMinus;{\mathrm{\&delta;}}_x)}{d_0}---\left(10\right)$

in FIG. 8, C_LAnd C_RDifferential capacitor pair_xWill produce + -delta_xAnd + -. DELTA.C_τIn response to (2) the response of (c),δ₀should be of a size thatDesirable delta₀10 μm, whereby equation (8) can be modified

$C_{\mathrm{\&tau;}x}=c_{\mathrm{\&tau;}0}+\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{{\mathrm{Ga}}_0}{F}_x---\left(11\right)$

In the formula,the initial capacitance when the shear stress is zero, and the formula (11) is the shear stress input-output characteristic, C_τxAnd F_xIs a linear relationship, andits sensitivity

A is shown in formula (11)₀The smaller the sensitivity of the tangential stress response is, the larger the capacitance unit of the present invention is, the more the strip-shaped capacitance unit group composed of a plurality of strip-shaped capacitors is adopted.

2.4.2 tangential stress Direction calculation

C_ⅠTo C_ⅡAnd C_ⅢTo C_ⅣTwo pairs of differential combinations can be realized, such as the signal differential diagram of the cell capacitor pair of FIG. 9, processed by differential techniques, the total response of the differential output

$O_{\mathrm{\&tau;}x}=\frac{2{\mathrm{mK\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{a_{0}G}{F}_x$

In which either the normal excitation F_nOr tangential excitation F_yAll are not to O_τEffecting, i.e. automatically cancelling, sigma_nAnd τ_yFor tau_xOr interference of the total output. Because the equivalent and congruent capacitance changes are automatically eliminated in all operations in which the signals contain subtraction. And F_yAnd F_xTo sigma_nCan pass through the upper electrode at b₀Direction increased geometric length 2 delta₀And (4) eliminating.

In the same way, the method for preparing the composite material, $O_{\mathrm{\&tau;}y}=\frac{2{\mathrm{mK\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{a_{0}G}{F}_y;$

according to O_τxAnd O_τyThe value of (c) calculates the direction of the tangential force.

2.4 selection of the principal materials and their characteristic parameters

The cross-sectional view of the parallel plate capacitor structure is similar to a sandwich structure as shown in FIG. 10. As shown in fig. 10, 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)}The deformation of the internal dielectric of the capacitor in a stress state is far larger than that of the polar plate because the internal dielectric of the capacitor is 103 GPa.

2.5 electrode lead design

Both the driving electrodes and the sensing electrodes need to be provided with lead-out lines, and considering that the respective driving electrodes are grounded in signal level, the driving electrodes need only share the same lead-out line. The driving electrodes of the circular ring capacitor unit group and the strip capacitor unit group are connected with a sensing system signal processor through an outgoing line, and each circle of the circular ring capacitor unit groupThe ring single lead is connected with a sensing system signal processor, the sensing system signal processor calculates according to the output value of each ring in a free combination mode, then averaging is carried out to obtain the magnitude of tangential force and the magnitude of normal force, under the condition that the precision requirement is not high, the ring capacitor unit group can only select two optimal rings to lead out 2 leads, and d is obtained through the two rings_xAnd d_nSo as to obtain the magnitude of the tangential force and the magnitude of the normal force; the X-direction differential capacitance unit group and the Y-direction differential capacitance unit group are respectively led out through an outgoing line to be connected with the sensing system signal processor and used for calculating the direction of the tangential force. An intermediate converter is arranged between the sensing system signal processor and the capacitor unit and is used for setting the transmission coefficient of voltage or frequency to the capacitor. The entire capacitor assembly has at least 7 pins leading out from the side of the planar package so that the top and bottom outer surfaces of the entire assembly can be conveniently contacted with the measurement object.

The utility model discloses under the support of new material and new technology, accomplished the design of a novel three-dimensional force sensitive capacitor combination. At 10X 10mm²The stress surface can transmit the stress to the medium more uniformly in the normal direction or the tangential direction. In the contact of space force and sensor surface, the external force is only 1, and the normal direction F can be obtained by summing the capacitances_nInformation of (2), i.e. the whole electrode plate is aimed at F_nMake a contribution to obtain F_xAnd F_yThe three-dimensional force can be completely described, and the normal sensitivity, the tangential sensitivity and the maximum linear error of one-time conversion can be improved according to design parameters.

The present invention has been described above with reference to the accompanying drawings, and it is obvious that the present invention is not limited by the above-mentioned manner, and various insubstantial improvements can be made without modification to the method and technical solution of the present invention, or the present invention can be directly applied to other occasions without modification, all within the scope of the present invention. The protection scope of the present invention shall be subject to the protection scope defined by the claims.

Claims (10)

1. A measuring device for the acting force between a foot sole and a starting device in sprinting is characterized by comprising a three-dimensional force measuring starting device, a gait recognition unit and a sensing system signal processor, wherein a pedal distance 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 foot sole 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, the gait recognition unit wirelessly connected with the sensing system signal processor comprises a foot sole pressure sensor and a wireless communication unit which are arranged in a shoe interlayer, the three-dimensional force pressure sensors comprise a circular capacitor unit group and a strip capacitor unit group, the strip capacitor unit group is arranged at four corners of a substrate outside the circular capacitor unit group, the circular capacitor unit group comprises more than two pairs of circular capacitor unit pairs, the ring capacitor unit pair comprises two ring capacitor units, the strip capacitor unit group comprises an X-direction differential capacitor unit group and a Y-direction differential capacitor unit group, the X-direction differential capacitor unit group and the Y-direction differential capacitor unit group respectively comprise more than two capacitor unit modules which mutually form a differential motion, each capacitor unit module is of a comb-tooth-shaped structure formed by more than two strip capacitor units, and each ring capacitor unit and each strip capacitor unit respectively comprise a driving electrode of an upper polar plate and an induction electrode of a lower polar plate.

2. The apparatus for measuring interplanted force between a sole and a starting block in sprinting according to claim 1, wherein the plantar pressure sensors are provided in five groups per foot, the three groups are provided at the fore-sole of the midsole for measuring the reaction force of the pedal against the foot, and the two groups are provided at the toe portion of the midsole for measuring the reaction force of the ground against the foot.

3. The device for measuring the acting force between the sole and the starting block in the sprint according to claim 1, wherein the sensing system signal processor comprises a signal conversion and amplification unit, a data processing unit and a controller which are connected in sequence, the controller is used for receiving the data output by the data processing unit and analyzing and calculating to determine the optimal data of the sprint training index, the data processing unit comprises a data filtering unit, a data classification unit, a data fusion processing unit and a database unit, the data filtering unit is used for filtering the error data collected by the sensor, the data classification unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data of the data classification unit and outputs a two-dimensional data table, and the database is used for storing the detection data and the standard data.

4. The apparatus for measuring inter-sole and starting runner effort during sprinting according to claim 1, wherein the sensing system signal processor further comprises an information input unit, the information input unit comprising sprinter information, the information comprising height, weight, leg metrics and step metrics.

5. The device for measuring the acting force between the sole and the starting block in sprinting according to claim 1, wherein the sensing electrode and the driving electrode of each circular ring capacitor unit are opposite and have the same shape, the driving electrode and the sensing electrode of each strip capacitor unit have the same width, the driving electrode of each strip capacitor unit is longer than the sensing electrode, and the left difference δ is reserved at each end of the driving electrode of each strip capacitor unit_{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.

6. Device for measuring the force acting between the sole of a foot and a starting block during sprinting according to claim 5, wherein the left difference δ of the strip-shaped capacitor unit_{Left side of}Right difference delta_{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 device for measuring the acting force between the sole and the starting block in sprinting according to claim 1, wherein the driving electrodes and the sensing electrodes of the two strip-shaped capacitor units forming the differential capacitor unit module with each other are provided with initial offset along the width direction, and the offset is the same in size and opposite in direction.

8. The apparatus for measuring acting force between sole and starting block in sprinting according to claim 1, wherein the ring capacitor unit group comprises n concentric rings capacitor units, whereinWherein, a_{Flat plate}Length of parallel plate, r_{Round (T-shaped)}Is the width of the ring capacitor unit, a_{Delta circle}The electrode distance between two adjacent circular capacitor units, the X-direction differential capacitor unit group and the Y-direction differential capacitor unit group both comprise m strip-shaped capacitor units, wherein, a_{Flat plate}Length of parallel plate, a_{Delta bar}Is the electrode spacing between two adjacent strip-shaped capacitor units, a₀Width of strip-shaped capacitor unit, width r of concentric ring capacitor unit_{Round (T-shaped)}And the width a of the strip-shaped capacitor unit₀Equal; electrode spacing a of strip-shaped capacitor unit_{Delta bar}And the electrode spacing a of the circular ring capacitor unit_{Delta circle}Equal, 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.

9. The device for measuring the acting force between the sole and the starting block in sprinting according to claim 1, wherein the driving electrodes of the circular capacitive cell group and the strip capacitive cell group are connected to the sensing system signal processor through a lead wire, the sensing electrode of each circular capacitive cell of the circular capacitive cell group is individually connected to the sensing system signal processor through a lead wire, and the sensing electrodes of the capacitive cell modules of the X-direction differential capacitive cell group and the Y-direction differential capacitive cell group are connected to the sensing system signal processor through a lead wire, respectively.

10. The apparatus for measuring the acting force between the sole and the starting block in sprinting according to claim 1, wherein intermediate transformers for setting the transmission coefficient of voltage to capacitance or frequency to capacitance are respectively provided between the circular ring capacitance unit, the capacitance unit module and the sensing system signal processor.