CN204798786U - Trainer is assisted in boxing based on pressure analysis - Google Patents

Abstract

The utility model relates to a trainer is assisted in boxing based on pressure analysis, the device include the three -dimensional ressure measurement unit of target body, boxing glove ressure measurement unit, position appearance recognition cell, speed recognition cell and sensing system signal processor, the three -dimensional ressure measurement unit of target body, boxing glove ressure measurement unit, position appearance recognition cell, speed recognition cell are connected with sensing system signal processor respectively, speed recognition cell is used for gathering out fist speed, position appearance recognition cell includes waist pressure sensor, shoulder joint pressure sensor, elbow joint pressure sensor, shank muscle pressure touch sensor and thigh muscle pressure touch sensor. Utilizing three -dimensional power pressure sensor, utilizing three -dimensional power pressure sensor, can detect out the power that is used in x on the boxing target body, y, the three orientation of z, be used for the training to instruct the three -dimensional pressure data that are used in on the target body, improve the score, measuring method is convenient simple.

Description

Boxing auxiliary training device based on pressure analysis

Technical Field

The utility model belongs to the training field is assisted in the motion, involves the boxing motion, concretely relates to training device is assisted in boxing motion based on pressure analysis.

Background

In the taekwondo and boxing sports, the striking motion of the player can be divided into two cases of striking the target body in a prescribed motion and striking the target body at will. The strength and direction of the force when the athlete hits the target, the time interval between hitting actions, whether the hitting part is accurate and the like can quantitatively depict the condition of the motion completion quality of the athlete. The coach can guide the athlete to carry out scientific training according to the data. The training quality is improved and the actual combat capability is enhanced, so that the method has important practical significance.

In order to improve the scientificity of daily training of taekwondo and boxing players, a novel three-dimensional force sensor is designed according to some characteristics of the competitive sports and some special requirements of the sensor on the characteristics. The device can accurately reflect the size and direction of force when a user strikes a target, the time interval between striking actions and the accuracy of a striking part in real time.

SUMMERY OF THE UTILITY MODEL

In order to overcome prior art's not enough, the utility model provides a training device is assisted in boxing based on pressure analysis adopts capacitanc pressure sensor to gather plantar pressure, through the rational arrangement to capacitanc pressure sensor's drive electrode and response electrode position to the differential electric capacity method of introduction realizes measuring the three-dimensional power that the sportsman acted on the target body.

The technical scheme of the utility model is that: the acting force measuring device comprises a target body three-dimensional pressure measuring unit, a boxing glove pressure measuring unit, a pose recognition unit, a speed recognition unit and a sensing system signal processor, the target body three-dimensional pressure measuring unit, the boxing glove pressure measuring unit, the pose identification unit and the speed identification unit are respectively connected with the sensing system signal processor, the speed identification unit is used for collecting the punching speed, the pose identification unit comprises a waist pressure sensor, a shoulder joint pressure sensor, an elbow joint pressure sensor, a shank muscle pressure sensor and a thigh muscle pressure sensor, the target body three-dimensional pressure measuring unit, the boxing glove pressure measuring unit, the waist pressure sensor, the shoulder joint pressure sensor, the elbow joint pressure sensor, the shank muscle pressure sensor and the thigh muscle pressure sensor are all groove type capacitance pressure sensors. The boxing glove pressure measuring unit arranged in each boxing glove comprises ten groups of groove type capacitive pressure sensors and a wireless communication unit, the ten groups of groove type capacitive pressure sensors are respectively corresponding to ten finger joints for receiving, and the boxing glove pressure measuring unit carries out signal transmission through the wireless communication unit and a sensing system signal processor. The data processing unit comprises a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, wherein the data filtering unit is used for filtering error data collected by the sensors, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data collected by each sensor classified by the data classifying unit to output a two-dimensional data table, the database unit is used for storing detection data and standard data, and the standard data is the optimal data of the target hitting index of boxing. 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 polar plate and the response electrode of polar plate down.

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 elastic medium, G is the shear modulus, τ, of the elastic medium_maxThe maximum stress value. The driving electrodes and the induction 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 deviation along the width directionThe offset is the same and opposite in direction. 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, a_{flat plate}/(a₀+a_{Delta bar}) Wherein a is_{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_δElectrode spacing a of strip and ring capacitor unit_δThe circles are equal, the 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 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 connected with the sensing system signal processor through an outgoing line respectively. 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 voltage to capacitor or frequency to electricityThe transmission coefficient of the capacitor. The sensor system signal processor comprises a multi-channel signal high-speed switching circuit, an A/D conversion circuit and a control circuit, wherein the high-speed switching circuit comprises a three-stage switching circuit, the output of the previous stage switching circuit is the input signal of the next stage switching circuit, and the last stage switching circuit is sent into the control circuit through the A/D conversion circuit.

The utility model discloses there is following positive effect: the force in the x direction, the y direction and the z direction acting on the boxing target body can be detected by utilizing the three-dimensional force pressure sensor, the three-dimensional pressure data acting on the target body is used for training guidance, and the measuring method is convenient and simple. 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 to better dynamic behavior has.

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.

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: a plurality of pressure sensors are arranged in the boxing target body and used for detecting three-dimensional force during boxing, the boxing frequency is judged through the capacitance value interval read by a computer, each sensor is numbered, the sensor numbers correspond to the positions of the boxing target body one by one, and the accuracy of the hitting positions is analyzed.

The measuring device of the utility model comprises a target body three-dimensional pressure measuring unit, a boxing glove pressure measuring unit, a pose recognizing unit, a speed recognizing unit and a sensing system signal processor, the target body three-dimensional pressure measuring unit, the boxing glove pressure measuring unit, the pose identification unit and the speed identification unit are respectively connected with the sensing system signal processor, the speed identification unit is used for collecting the punching speed, the pose identification unit comprises a waist pressure sensor, a shoulder joint pressure sensor, an elbow joint pressure sensor, a shank muscle pressure sensor and a thigh muscle pressure sensor, the target body three-dimensional pressure measuring unit, the boxing glove pressure measuring unit, the waist pressure sensor, the shoulder joint pressure sensor, the elbow joint pressure sensor, the shank muscle pressure sensor and the thigh muscle pressure sensor are all groove type capacitance pressure sensors.

The boxing glove pressure measuring unit arranged in each boxing glove comprises ten groups of groove type capacitive pressure sensors and a wireless communication unit, the ten groups of groove type capacitive pressure sensors are respectively corresponding to ten finger joints for receiving, and the boxing glove pressure measuring unit carries out signal transmission through the wireless communication unit and a sensing system signal processor.

The data processing unit comprises a data filtering unit, a data classifying unit, a data fusion processing unit and a database unit, wherein the data filtering unit is used for filtering error data collected by the sensors, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data collected by each sensor classified by the data classifying unit to output a two-dimensional data table, the database unit is used for storing detection data and standard data, and the standard data is the optimal data of the target hitting index of boxing. According to the data that influence the boxing of gathering to carry out the fusion processing to data, further promote the precision of boxing motion analysis. All groove type capacitance pressure sensors are connected with the data processing unit after being subjected to A/D conversion and an amplifier.

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 capacitor unit group comprises more than two groups of ring capacitor unit pairs, each ring capacitor unit pair comprises two ring capacitor units, each strip-shaped capacitor unit group comprises an X-direction differential capacitor unit group and a Y-direction differential capacitor unit group, and the X-direction differential capacitor unit groups and the Y-direction differential capacitor unit groupsThe differential capacitor unit group comprises more than two capacitor unit modules which mutually form a differential motion, the capacitor unit modules adopt a comb-shaped structure consisting of more than two strip-shaped capacitor units, and each ring-shaped capacitor unit and each strip-shaped capacitor unit respectively comprise a driving electrode of an upper polar plate and an induction electrode of a lower polar 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 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 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,a_{flat plate}/(a₀+a_{Delta bar}) Wherein a is_{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_nNormal linearity in the conversion characteristic ofIs 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 calculated The resulting capacitance is:

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

according to shear Hooke's law

τ_x＝γ_x·G＝G·δ_x/d₀(7)

Substituting (7) into (6) to obtain

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

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

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

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, atEach 10X 10mm²The 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 fig. 5, a rectangular coordinate system of the plate capacitor is shown, where the origin of the coordinate system is at the origin of a concentric circle of the circular capacitor unit group, the X-axis and the Y-axis are along the diagonal direction 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, the X-direction differential capacitor unit group i and the X-direction differential capacitor unit group iii are located on the positive and negative half axes of the X-axis and are symmetric along the Y-axis, the Y-direction differential capacitor unit group includes a Y-direction differential capacitor unit group ii and a Y-direction differential capacitor unit group iv, the Y-direction differential capacitor unit group ii and the Y-direction differential capacitor unit group iv are located on the positive and negative half axes of the Y-axis and are symmetric along_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,flat/(a)₀+a_δA strip) in which a_δThe strip is provided with an electrode distance between two adjacent strip-shaped capacitor units, a₀The 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_δStrip and ring capacitor electrode spacing a_δThe circles are equal, the 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

The circular-ring capacitor unit is placed in a rectangular coordinate system shown in fig. 5, 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 Fx and Fy are along the X axis and the Y axis, and the acting direction of 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, 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: μm) of the elastic medium, δ x and δ y are the relative dislocation (unit: μm) of the upper and lower electrode plates of the circular ring capacitor unit, and the sign of the displacement is 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.

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

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

Will be first to secondObtaining:

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

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

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: $F_n=\frac{(d_n-d_0)E\&CenterDot;S_0}{d_0}$

will be described in the above₂-②*C₁Obtaining:

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

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

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

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_yTangential response does not mutually influence, and a reserved difference 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 ${10}^{-5}\&times;\frac{70\&times;{10}^3}{2.4\&times;{10}^6}=2.9\&times;{10}^{-8}m={10}^{-2}um<<1um,$ 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 ensureProve 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, and the sensitivity thereof

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_xTotal output ofOut coupling or interference. 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 ring capacitor unit group and the strip capacitor unit group are connected with a sensing system signal processor through an outgoing line, each ring independent lead of the ring capacitor unit group is connected with the sensing system signal processor, the sensing system signal processor calculates according to the output value free combination of each ring, then averaging is carried out to obtain the size of the tangential force and the size of the 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.

Since the frequency of boxing during boxing training may be several times a second, a high sampling rate is required. The multi-path signal high-speed switching circuit, the A/D conversion circuit and the control circuit are used for collecting signals of the pressure sensor, in order to save the A/D conversion circuit, the measurement of the multi-path pressure sensor is completed by one path of the A/D conversion circuit, the multi-path signal high-speed switching circuit and the control circuit are the design key of a system, and the switching speed influences the data volume tested in the short boxing process. The utility model discloses an acquisition circuit carries out the signal switching to 256 way sensors simultaneously. After local shaping, a control system from the control circuit is switched in three stages, 32 8 switches are used for parallel work in the first stage, 32 signals are output, the 32 signals enter the second stage switch, 4 8 switches are adopted for parallel work to obtain 4 signals, and the 4 signals enter the third stage switch to obtain 1 signal and enter the A/D conversion circuit. The A/D conversion circuit reads data into the computer for temporary storage in the conversion process, and all the data are stored in the computer after being read.

In the actual use process, the sensors are numbered, the three-dimensional force measured by each sensor corresponds to the position of the corresponding boxing target body one by using a computer, and the boxing frequency can be calculated through the time interval of two times of capacitance mutation points.

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.

Claims (10)

1. The utility model provides a boxing exercise training aiding device based on pressure analysis, its characterized in that, this effort measuring device include target body three-dimensional pressure measuring unit, boxing glove pressure measuring unit, position appearance recognition unit, speed recognition unit and sensing system signal processor, target body three-dimensional pressure measuring unit, boxing glove pressure measuring unit, position appearance recognition unit, speed recognition unit are connected with sensing system signal processor respectively, speed recognition unit is used for gathering out fist speed, position appearance recognition unit includes waist pressure sensor, shoulder joint pressure sensor, elbow joint pressure sensor, shank muscle pressure touch sensor and thigh muscle pressure touch sensor, target body three-dimensional pressure measuring unit, boxing glove pressure measuring unit, waist pressure sensor, shoulder joint pressure sensor, elbow joint pressure sensor, The shank muscle pressure sensor and the thigh muscle pressure sensor both adopt groove type capacitance pressure sensors.

2. A boxing glove pressure measuring unit as claimed in claim 1, wherein the boxing glove pressure measuring unit arranged in each boxing glove comprises ten groups of groove type capacitive pressure sensors and a wireless communication unit, the ten groups of groove type capacitive pressure sensors respectively correspond to ten finger joints, and the boxing glove pressure measuring unit is in signal transmission through the wireless communication unit and a sensing system signal processor.

3. A boxing auxiliary training device as claimed in claim 1, wherein 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 the sensors, the data classifying unit classifies the filtered data, the data fusion processing unit performs fusion processing according to the data collected by the sensors classified by the data classifying unit to output a two-dimensional data table, and the database unit is used for storing detection data and standard data, and the standard data is optimal data of target hitting indexes.

4. A boxing training aid as claimed in claim 1, wherein the groove type capacitive pressure sensor comprises a ring-shaped capacitive cell group and a strip-shaped capacitive cell group, the strip-shaped capacitor unit groups are arranged at four corners of the outer substrate of the circular ring capacitor unit group, the circular ring capacitor unit group comprises more than two pairs of circular ring 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, the capacitor unit module is of a comb-tooth-shaped structure consisting of more than two strip-shaped capacitor units, and each ring-shaped capacitor unit and each strip-shaped capacitor unit respectively comprise a driving electrode of an upper polar plate and an induction electrode of a lower polar plate.

5. A boxing auxiliary training device as claimed in claim 4, 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 length of the driving electrode of each strip capacitor unit is greater than that of the sensing electrode, and a left difference delta is reserved at each end 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}Is the length of the induction electrode of the strip-shaped capacitor unit, and the 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.

6. A boxing training aid as claimed in claim 4, wherein the drive electrodes and the sense electrodes of the two strip-shaped capacitor units forming the differential capacitor unit module are provided with initial offset along the width direction, and the offset is the same and opposite.

7. A boxing training aid as claimed in claim 4, wherein the circular ring capacitor unit group comprises n concentric circular ring 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.

8. A boxing auxiliary training device as claimed in claim 4, wherein the driving electrodes of the circular ring capacitor unit groups and the strip capacitor unit groups are connected with the sensing system signal processor through a leading line, the sensing electrode of each circular ring capacitor unit of the circular ring capacitor unit groups is separately connected with the sensing system signal processor through a leading line, and the sensing electrodes of the capacitor unit modules of the X-direction differential capacitor unit groups and the Y-direction differential capacitor unit groups are respectively connected with the sensing system signal processor through a leading line.

9. A boxing training aid as claimed in claim 4, wherein intermediate converters are provided between the ring capacitor unit, the capacitor unit module and the sensing system signal processor, and are used for setting transmission coefficients of voltage to capacitance or frequency to capacitance.

10. A boxing training aid as claimed in claim 4, wherein the sensor system signal processor comprises a multi-signal high-speed switching circuit, an A/D conversion circuit and a control circuit, the high-speed switching circuit comprises three stages of switching circuits, the output of the former stage of switching circuit is the input signal of the next stage of switching circuit, and the last stage of switching circuit is fed into the control circuit through the A/D conversion circuit.