CN104997524A - Bicycle cycling parameter acquisition device - Google Patents

Abstract

The invention relates to a bicycle cycling parameter acquisition device comprising pedal sensors, encoders, and sensor system signal processors. Each encoder is mounted at an outer end of a pedal shaft, and is used to acquire the included angle Beta between a crank and a corresponding pedal at any time and solve the ineffective force along the direction of a crank shaft and the effective force in the vertical direction. The pedal sensors are arranged on the left and right pedals of a test bicycle. Each pedal sensor includes a sensor system signal processor, and a ring capacitor unit group and a strip capacitor unit group which are connected with the sensor system signal processor. The ring capacitor unit groups are used to measure the magnitude of tangential force and the magnitude of normal force, and the strip capacitor unit groups are used to measure the direction of tangential force. The bicycle cycling parameter acquisition device of the invention provides theoretical basis for finding setting posture positioning suitable for the body structure features of trainees and obtaining the optimal bicycle frame structure size for each measured cyclist.

Description

A kind of cycling motion parameter collecting device

Technical field

The invention belongs to athletic training technical field, relate to training cycles project, be specifically related to a kind of cycling motion parameter collecting device.

Background technology

In cycling, scrunching is the sole power that people and Herba Plantaginis enter, good step on juggling with the feet art athlete can be made to obtain maximum power with minimum energy expenditure, and fall behind, the stepping on juggling with the feet art and too can consume athletic physical ability of mistake, but can not get corresponding effect.From the geometry of bicycle, when riding, driver and bicycle contacts position only have three places: handlebar, car are sat and pedal.Therefore foot, buttocks and the relative position of arm on bicycle determine the transmission of comfort level and the active force of riding.Such as, the angle between footboard and crank axle, can affect trainer's foot and act on normal force on pedal and the tangential force component size along effective force and inefficacious direction, affect virtuous functioning efficiency.Therefore, be necessary to monitor the active force of motor process mesopodium, buttocks and arm, help trainer to adjust riding posture, and train the best to step on juggling with the feet art.

Summary of the invention

In order to overcome the deficiencies in the prior art, the invention provides a kind of cycling motion parameter collecting device, by monitoring appearance position, experimenter upper body, change sit angle, the pedal caused by sitting height, car are sat, hands the change of upper kinetic parameter, thus for the sitting posture location that is suitable for trainer's organization of human body characteristic and provide theoretical foundation and effective initial data for surveyed each cyclist obtains body frame structure for automotive size optimum separately.

Technical scheme of the present invention is: a kind of cycling motion parameter collecting device, comprise pedal sensor, encoder and sensor system signals processor, encoder is arranged on the outer end of crank shaft, for obtain any time crank and pedal between angle β, solve the effective force along the axial inefficacious and vertical direction of crank, pedal transducer arrangements is on the left and right pedal of test carriage, obtain the three-dimensional force acted on pedal, described pedal sensor comprises sensor system signals processor, the annulus capacitor cell group be connected respectively with sensor system signals processor and strip capacitor cell group, described strip capacitor cell group is arranged on the corner of the outer substrate of annulus capacitor cell group, annulus capacitor cell group comprises two to above annulus capacitor cell pair, described annulus capacitor cell is to comprising two annulus capacitor cells, described strip capacitor cell group comprises X-direction differential capacitor unit group and Y-direction differential capacitor unit group, X-direction differential capacitor unit group and Y-direction differential capacitor unit group include two or more and mutually form differential capacitor cell module, the comb teeth-shaped structure that described capacitor cell module is made up of plural strip capacitor cell, each annulus capacitor cell and strip capacitor cell include the drive electrode of top crown and the induction electrode of bottom crown.

Cycling motion parameter collecting device also comprises handlebar sensor and vehicle seat sensor, for monitoring the three-dimensional active force on vehicle seat and handlebar, obtains the distribution of weight of upper body and the firmly feature of trunk-hand arm system.The induction electrode of described each annulus capacitor cell and drive electrode just to and shape is identical, the drive electrode of described each strip capacitor cell is identical with induction electrode width, the drive electrode length of strip capacitor cell is greater than induction electrode length, the drive electrode length two ends reserved left poor position δ respectively of strip capacitor cell _leftwith right poor position δ _right, b _{0 drives}=b _{0 sense}+ δ _right+ δ _left, wherein b _{0 drives}for the drive electrode length of strip capacitor cell, b _{0 sense}for the induction electrode length of strip capacitor cell.The left poor position δ of described strip capacitor cell _left=right poor position δ _right, and wherein d ₀for elastic fluid thickness, G is the modulus of rigidity of elastic fluid, τ _maxfor maximum stress value.Described two groups of drive electrodes mutually forming the strip capacitor cell of differential capacitor cell module and induction electrode are provided with the skew that initially misplaces in the width direction, and dislocation bias size is identical, direction is contrary.Described annulus capacitor cell group comprises n donut capacitor cell, wherein wherein, a _flatfor the length of parallel-plate, r _circlefor the width of annulus capacitor cell annulus, a _{δ circle}electrode spacing between adjacent two annulus capacitor cells.X-direction differential capacitor unit group and Y-direction differential capacitor unit group include m strip capacitor cell, wherein, a _flatfor the length of parallel-plate, a _{δ bar}for the electrode spacing between adjacent two strip capacitor cells, a ₀the width of strip capacitor cell.The width r of described donut capacitor cell _circlewith the width a of strip capacitor cell ₀equal; Strip capacitor cell electrode spacing a _{δ bar}with annulus capacitor cell electrode spacing a _{δ circle}equal, the width of described strip capacitor cell wherein, d ₀for elastic fluid thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.Described annulus capacitor cell group is connected with sensor-based system signal processor by a lead-out wire with the drive electrode of strip capacitor cell group, the induction electrode of each annulus capacitor cell of described annulus capacitor cell group goes between separately and to be connected with sensor-based system signal processor, and described X-direction differential capacitor unit group is connected with sensor-based system signal processor respectively by a lead-out wire with the capacitor cell module induction electrode of Y-direction differential capacitor unit group.Described annulus capacitor cell, be respectively equipped with intermediate translator between capacitor cell module and sensor-based system signal processor, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.

The present invention has following good effect: cycling motion parameter collecting device of the present invention, by monitoring appearance position, experimenter upper body, change sit angle, the pedal caused by sitting height, car are sat, hands the change of upper kinetic parameter, find the sitting posture location that is suitable for trainer's organization of human body characteristic and provide theoretical foundation for surveyed each cyclist obtains body frame structure for automotive size optimum separately.

Accompanying drawing explanation

Fig. 1 is the donut skew dislocation areal analysis figure of the specific embodiment of the present invention.

Fig. 2 be the specific embodiment of the present invention for the dislocation of outer donut is to external diameter circle analysis chart.

Fig. 3 is the plane design drawing of the parallel plate capacitor of the specific embodiment of the present invention.

Fig. 4 is the structure chart of the drive electrode of the specific embodiment of the present invention.

Fig. 5 is the rectangular coordinate system of the capacity plate antenna plate of the specific embodiment of the present invention.

Fig. 6 is two groups of annulus capacitance group structure charts of the specific embodiment of the present invention.

Fig. 7 is the initial dislocation figure of the differential strip capacitor cell of the specific embodiment of the present invention.

Fig. 8 is the stressed rear deflection graph of differential strip capacitor cell of the specific embodiment of the present invention.

Fig. 9 is the differential schematic diagram of signal that the cell capacitance of the specific embodiment of the present invention is right.

Figure 10 is the plane-parallel capacitor cross-section structure of the specific embodiment of the present invention.

Figure 11 is the foot-operated upper stressing conditions analysis chart of the car of the specific embodiment of the present invention.

Wherein, 1, upper PCB substrate, 2, lower PCB substrate, 3, drive electrode, 4, induction electrode, 5, elastic fluid.

Detailed description of the invention

Contrast accompanying drawing below, by the description to embodiment, the specific embodiment of the present invention is as the effect of the mutual alignment between the shape of involved each component, structure, each several part and annexation, each several part and operation principle, manufacturing process and operation using method etc., be described in further detail, have more complete, accurate and deep understanding to help those skilled in the art to inventive concept of the present invention, technical scheme.

As shown in figure 11, be the foot-operated upper stressing conditions analysis chart of cycle test car, the left side is crank coordinate system, and the right, for acting on the force analysis on pedal, after pedal three-dimensional force tests out, for terrestrial coordinate system, will act on the normal force (F on pedal _pn) and tangential force (F _pt) along the Directional Decomposition that crank axle is parallel and vertical with crank axle time, record according to encoder corresponding moment footboard and crank axle between angle β, so just can in the hope of the component along crank axle parallel direction, also namely inefficacious, and the component in the direction vertical with crank axle, be also effective force, effective force is exactly functioning efficiency with the ratio of making a concerted effort, functioning efficiency is the evaluation index spoiling juggling with the feet art, and to spoil juggling with the feet art be control posture, load and spoil the embodiment directly perceived pedaling frequency.Therefore, test carriage left and right pedal installs three-dimensional force sensor, monitoring foot acts on tangential force on pedal and normal force, high and spoil and pedal frequency by changing seat angle, seat, act on tangential force on pedal and normal force binding mode can change, in the outer end of crank shaft, encoder is installed, the angle between acquisition any time crank and pedal.

Also loading onto three-dimensional force sensor under a car seat with under handlebar, for monitoring the active force on vehicle seat and handlebar, thus seeking the distribution of weight of upper body and the stability features of trunk-hand arm system when changing the amount of riding.The active force feature at comprehensive three places guarantees that the best rides reasonability and the science of appearance location.Handlebar, vehicle seat, left and right pedal three-dimensional force sensor and the 15 road signals such as left and right pedal encoder and sampling time sequence are nursed one's health in signal conditioner, through ADC conversion laggard enter microprocessor.Microprocessor simultaneously control synchronization luminous point (with realize kinesiology, kinetic measurement synchronous), and to be connected with PC by USB interface.Software can realize from functions such as data acquisition, date processing, data storage and data readbacks.

Effective force, inefficacious and can try to achieve according to following formula with joint efforts accordingly: F _{effective force}=-F _ptcos β+F _pnsin β; F _{inefficacious}=-F _ptsin β+F _pncos β;

The measuring principle of three-dimensional force sensor of the present invention is below described: sensor of the present invention comprises annulus capacitor cell group and strip capacitor cell group, described annulus capacitor cell group is for surveying the size of tangential force and normal force, institute's strip capacitor cell group is for measuring the direction of tangential force, and described strip capacitor cell group is arranged on the corner outside substrate annulus capacitor cell group.Annulus capacitor cell group comprises annulus capacitor cell pair more than two, described annulus capacitor cell is to comprising two annulus capacitor cells, described strip capacitor cell group comprises X-direction differential capacitor unit group and Y-direction differential capacitor unit group, X-direction differential capacitor unit group and Y-direction differential capacitor unit group include two or more and mutually form differential capacitor cell module, described capacitor cell module adopts the comb teeth-shaped structure be made up of plural strip capacitor cell, each annulus capacitor cell and strip capacitor cell include the drive electrode of top crown and the induction electrode of bottom crown.The induction electrode of described each annulus capacitor cell and drive electrode just to and shape is identical, the drive electrode of described each strip capacitor cell is identical with induction electrode width, the drive electrode length of strip capacitor cell is greater than induction electrode length, the drive electrode length two ends reserved left poor position δ respectively of strip capacitor cell _leftwith right poor position δ _right, b _{0 drives}=b _{0 sense}+ δ _right+ δ _left, wherein b _{0 drives}for the drive electrode length of strip capacitor cell, b _{0 sense}for the induction electrode length of strip capacitor cell.The left poor position δ of described strip capacitor cell _left=right poor position δ _right, and wherein d ₀for dielectric thickness, G is the modulus of rigidity of elastic fluid, τ _ymaxfor maximum stress value.Described two groups of drive electrodes mutually forming the strip capacitor cell of differential capacitor cell module and induction electrode are provided with the skew that initially misplaces in the width direction, and dislocation bias size is identical, direction is contrary.Described annulus capacitor cell group comprises n donut capacitor cell, wherein wherein, a _flatfor the length of parallel-plate, r _circlefor the width of annulus capacitor cell annulus, a _{δ circle}electrode spacing between adjacent two annulus capacitance.Described capacitor cell module adopts comb teeth-shaped structure, and X-direction differential capacitor unit group and Y-direction differential capacitor unit group include m strip capacitor cell, wherein, a _flatfor the length of parallel-plate, a _{δ bar}for the electrode spacing between adjacent two strip capacitor cells, a ₀the width of strip capacitor cell.The width r of described donut capacitor cell _circlewith the width a of strip capacitor cell ₀equal; Strip capacitor cell electrode spacing a _{δ bar}with annulus capacitor cell electrode spacing a _{δ circle}equal, the width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.Described annulus capacitor cell group is connected with sensor-based system signal processor by a lead-out wire with the drive electrode of strip capacitor cell group, the induction electrode of each annulus capacitor cell of described annulus capacitor cell group goes between separately and to be connected with sensor-based system signal processor, and described X-direction differential capacitor unit group is drawn each via a lead-out wire respectively with the capacitor cell module induction electrode of Y-direction differential capacitor unit group and is connected with sensor-based system signal processor.Described annulus capacitor cell, be respectively equipped with intermediate translator between capacitor cell module and sensor-based system signal processor, changer is for arranging voltage or frequency to the transmission coefficient of electric capacity.

Below in conjunction with accompanying drawing 1-10 to derivation of the present invention and principle, to effect and operation principle, manufacturing process and the operation using method etc. of the mutual alignment between each several part shape, structure, each several part and annexation, each several part, be described in further detail.

1.1 capacitance equation and input-output characteristic thereof

The initial capacitance of parallel-plate is:

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

In formula, ε ₀vacuum medium electric constant is 8.85PF/m, ε _r=2.5 is dielectric relative dielectric constant, A ₀for the initial right opposite of upper bottom crown amasss.D ₀by σ _nexcitation produce relative deformation ε _n=δ _n/ d ₀=σ _n/ E, (1) formula of substitution obtains input-output characteristic

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

The linearity under 1.2 normal stress effects and sensitivity

1.2.1 the normal direction linearity

(2) F in formula _nin the denominator, therefore C _n=f (F _n) relation be nonlinear.Because of the maximum σ in conversion range _nmaxcompared with dielectric resilient constant E, ε _na very little amount, i.e. ε in denominator _n<<1, omits the higher-order shear deformation of more than quadratic power by (2) formula by series expansion, can be reduced to:

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

Visible at C _nwith F _ntransfer characteristic in the maximum relative error of the normal direction linearity close to zero.

1.2.2 sensitivity

By the definition of normal direction sensitivity

By (2) formula then

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

Can linear sensitivity be obtained by (3) formula,

S _n1＝C ₀/AE＝ε ₀ε _r/d ₀E (5)

S _n2with F _nand become, F _nlarger, S _n2larger, in mild nonlinear in whole transfer characteristic.

Relation between 1.3 tangential displacements and annulus capacitor effective area

For donut electric capacity to analyzing, as shown in Figure 1, R ₁for exradius, R ₂for inner circle radius, r=annular width=large exradius R ₁-inner circle radius R ₂.To the power F on drive electrode tangent plane _x, cause drive electrode corresponding up and down and induction electrode to produce one and shear dislocation, if d _xfor tangent plane displacement, dislocation area is S _inand S _outward, the initial right opposite of battery lead plate is long-pending should be π (R ₁ ²-R ₂ ²).Fig. 2 is that outer donut electric capacity justifies analysis chart to external diameter, and before and after mobile, two distance of center circle are from being d _x, before and after mobile, the intersection point of two centers of circle and two circles forms a rhombus, can calculate S _outwardarea:

In above formula, there is d _x<<R ₁, so get

By

Will taylor series expansion, and omit high-order term,

In like manner, can know, S _in=2R ₂d _x, so the wrong area of donut electric capacity is S=2R ₁d _x+ 2R ₂d _x.

The capacitance variations of the annulus capacitor cell group under 1.4 tangential stress τ excitations

Tangential stress τ does not change the physical dimension parameter A of pole plate ₀, to dielectric thickness d ₀also do not have an impact.But τ _xand τ _ychange the space structure of plane-parallel capacitor, between the upper bottom crown faced by forward, there occurs dislocation skew.The dislocation offset d of pole plate under τ effect _x.When τ is zero, the upper/lower electrode of annulus capacitor cell is just right, effective cross-section between upper/lower electrode in fig. 2, at τ _xunder the effect of dextrad, top crown creates dislocation offset d to the right relative to bottom crown _x, thus make the effective area between bottom crown when calculating electric capacity consequent electric capacity 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 shearing Hooke's law

τ _x＝γ _x·G＝G·δ _x/d ₀(7)

(7) are substituted into (6) can 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) formula is the input-output characteristics under shearing stress, C _τwith τ _xlinear, its sensitivity

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

Tangential sensitivity and R can be found out by formula (9) ₁-R ₂relevant, namely the width of tangential sensitivity and annulus is inversely proportional to, and width more sluggishness is higher.

The design of 2 plate condensers

The design of 2.1 plate condensers

Arrange and the structure chart of Fig. 4 drive electrode, at a 10 × 10mm see the electrode plane in Fig. 3 ²substrate on a kind of circular ring type contact parallel-plate three-dimensional pressure sensor, sensor comprises annulus capacitor cell group and strip capacitor cell group, annulus capacitor cell group is for surveying the size of tangential force and normal force, strip capacitor cell group is for measuring the direction of tangential force, and strip capacitor cell group is arranged on the corner outside substrate annulus capacitor cell group.Effectively can use the area of parallel-plate like this, annulus capacitor cell group is paved with whole parallel-plate, when measuring three-dimensional force, all work, and strip capacitor cell group effectively make use of annulus capacitor cell group lay after, the space of parallel-plate corner, for measuring the direction of three-dimensional force tangential force.The drive electrode of annulus capacitor cell group and induction electrode are all made up of n donut, and n is even number, then form n/2 annulus capacitor cell pair.Hachure part represents the outer mode cross section of wax-loss casting process, and its geometry and size also should keep accurate when mechanical-moulded.

With reference to the rectangular coordinate system of the capacity plate antenna of Fig. 5, coordinate system origin is at the concentric circular initial point of annulus capacitor cell group, x-axis and y-axis are respectively along the diagonal of capacity plate antenna, X-direction differential capacitor unit group comprises X-direction differential capacitor unit group I and X-direction differential capacitor unit group III, X-direction differential capacitor unit group I and X-direction differential capacitor unit group III lay respectively at the positive and negative semiaxis of x-axis and symmetrical along y-axis, Y-direction differential capacitor unit group comprises Y-direction differential capacitor unit group II and Y-direction differential capacitor unit group IV, Y-direction differential capacitor unit group II and Y-direction differential capacitor unit group IV lay respectively at the positive and negative semiaxis of y-axis and symmetrical along x-axis, X-direction differential capacitor unit group I and X-direction differential capacitor unit group III are formed τ _xmake the differential capacitor unit combination of response, Y-direction differential capacitor unit group II and Y-direction differential capacitor unit group IV are formed τ _ymake the differential capacitor unit combination of response.

Annulus capacitor cell group comprises n donut capacitor cell, wherein wherein, a _flatfor the length of parallel-plate, r _circlefor the width of annulus capacitor cell annulus, a _{δ circle}electrode spacing between adjacent two annulus capacitance.Capacitor cell module adopts comb teeth-shaped structure, and X-direction differential capacitor unit group and Y-direction differential capacitor unit group include m strip capacitor cell, wherein, a _{δ bar}for being provided with electrode spacing, a between adjacent two strip capacitor cells ₀the width of strip capacitor cell.The width r of donut capacitor cell _circlewith the width a of strip capacitor cell ₀equal; Strip capacitor cell electrode spacing a _{δ bar}with annulus capacitance electrode spacing a _{δ circle}equal, the width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.

2.2 pumping signals and coordinate system

Annulus capacitor cell is placed in the rectangular coordinate system shown in Fig. 5, three-dimensional simulation puts on the outer surface of capacitor plate, the contact active force produced has Fx, Fy and Fz tri-durection components, and the action direction of Fx and Fy is along X-axis and Y-axis, and the action direction of Fz along OZ axle namely direction, normal direction and tangential stress are a kind of stress tensor, from can the response of output capacitance between the lead-in wire of electrode; Normal stress σ _n=Fn/A, wherein for pole plate normal direction stress surface, Fn=Fz is normal component; Both side surface produces paired tangential stress τ _cut=F _cut/ A.

According to the Hooke's law in Elasticity, σ _nand τ _x, τ _yelastomer all will be made to produce corresponding distortion.Wherein,

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

In formula, E is the Young's modulus GN/m of elastic fluid ², G is the modulus of rigidity GN/m of elastic fluid ², δ n is the Normal Displacement (unit: μm) of elastic fluid, and δ x and δ y is the relative dislocation (unit: μm) of the upper and lower two-plate of annulus capacitor cell, and its sign is pointed to by coordinate axes and determined.

The calculating of 2.3 normal force and tangential force size

Choosing the n-th annulus capacitor cell and the n-th/2 annulus capacitor cell, by setting up annulus capacitor cell, composition equation group being calculated, as shown in Figure 6.If after battery lead plate is subject to normal direction and tangential incentive action, if the output capacitance of the n-th annulus capacitor cell is C ₁, n/2 annulus capacitor cell output capacitance is C ₂, tangential displacement is d _x, the capacitance pole distance of normal direction is d _n, S ₁₀the right opposite initial for outer shroud amasss, S ₂₀the right opposite initial for internal ring amasss.

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

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

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

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

Above-mentioned is incited somebody to action 1. * C ₂-2. * C ₁obtain:

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

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 _τfor

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

The direction determining of 2.4 tangential forces

2.4.1 strip capacitor cell group shape structure and parameter design

In order to realize τ _xand τ _ymutually do not have an impact between tangential response, drive electrode length two ends reserved difference position δ ₀, therefore b _{0 drives}=b _{0 end}+ 2 δ ₀, wherein at b _{0 drives}two ends length is reserved should be ensured in theory its value of calculation is therefore should b be ensured in technique _{0 drives}-b _{0 end}>=0.01mm.Do not have an impact to the response of normal direction electric capacity to realize τ x and τ y, the drive electrode of each strip capacitor cell and induction electrode arrange certain dislocation in horizontal layout and offset, on by differential elimination impact each other.

As shown in Figure 4, in figure, four dashed rectangle are the benchmark of induction electrode on bottom crown, get the position of induction electrode in lower floor's PCB substrate as reference, then the layout of drive electrode in the PCB substrate of upper strata should with PCB substrate edge line for benchmark.Each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown, if often root strip capacitor cell is wide is a ₀, the groove width between two strip capacitor cells is a _δ, then the pitch of every root strip capacitor cell is a ₀+ a _δ.τ can be ensured like this when computing method exports response to electric capacity _xand τ _ythe response of normal direction electric capacity is not had an impact.And put they and geometry datum line differential apart from being δ ₀(0.1mm), to ensure that X-direction differential capacitor unit group I and X-direction differential capacitor unit group III produce τ _xdifferential capacitor export response, Y-direction differential capacitor unit group II and Y-direction differential capacitor unit group IV then only produce τ _ydifferential capacitor response, an initially dislocation skew δ is set _xo, its value should ensure its value of calculation and δ ₀similar, its skew that initially misplaces all arranges δ _xo=δ _yo=0.01mm, to ensure that four capacitor cells are at τ _xand τ _ytwo groups of differential capacitors pair can be produced under tangential excitation.

In Fig. 7, a pair electric capacity C _land C _relectrode size a ₀, b ₀, d ₀all identical, initial dislocation skew δ ₀also identical, difference is left side capacitor C _lupper strata δ ₀wedge angle be oriented to+OX, and the right capacitor C _rupper strata δ ₀wedge angle sensing-OX.Work as τ _xwhen=0, namely the electric capacity in figure corresponding to dash area.On this basis, as at-F _xlower generation ± the δ of excitation _xdislocation skew, formed as shown in Figure 8 electric capacity increase and decrease effect,

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

In Fig. 8, C _land C _rdifferential capacitor is to same τ _xby generation ± δ _xwith ± Δ C _τresponse, δ ₀size should meet desirable δ ₀=10 μm, thus, formula (8) can be revised as

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

In formula, for initial capacitance when shearing stress is zero, (11) formula is shearing stress input-output characteristic, C _{τ x}with F _xlinear relationship, and its sensitivity

By formula (11) known a ₀less, the sensitivity of tangential stress response is larger, therefore capacitor cell of the present invention adopts the strip capacitor cell group be made up of multiple strip electric capacity.

2.4.2 tangential stress direction calculating

C _ito C _iIand C _iIIto C _iVtwo can be realized to differential combination, the differential schematic diagram of the signal that the cell capacitance as Fig. 9 is right, through differential technique process, the overall response of differential output

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

In formula, no matter be normal direction excitation F _nor tangentially encourage F _yall not to O _τhave an impact, namely automatically eliminate σ _nand τ _yto τ _xthe coupling of total output or interference.Because every in signal packet containing in the computing of subtracting each other, equivalent and all automatically eliminating with the capacitance variations that meets.And F _yand F _xto σ _ninterference by upper electrode at b ₀direction increases geometrical length 2 δ ₀eliminate.

In like manner, $O_{\mathrm{\&tau;}y}=\frac{2{\mathrm{mK\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{a_{0}G}{F}_y;$

According to O _{τ x}and O _{τ y}value calculate the direction of tangential force.

2.4 main material selection and characterisitic parameter thereof

The section of structure of plane-parallel capacitor is similar to sandwich structure as shown in Figure 10.As shown in Figure 10,1 is upper PCB substrate, and 2 is lower PCB substrate, and 3 is drive electrode, and 4 is induction electrode, and 5 is elastic fluid.Pole plate is apart from d ₀=0.1mm, upper and lower base plate inner space, except copper foil electrode, is PDMS (polydimethylsiloxane) the superlastic dielectric with lost wax process filling.Its machinery and physical characteristic parameter are Young's modulus E=6.2MPa, and its shear modulus is G=4.1MPa, relative DIELECTRIC CONSTANT ε during dielectric polorization _γ=2.5.Because E and G of medium is much smaller than the elastic modulus E of copper _copper=103GPa, therefore the distortion of capacitor internal medium under stress state is much larger than the distortion of pole plate.

2.5 contact conductor designs

Be that drive electrode or induction electrode all need to have lead-out wire, consider that each drive electrode is all ground connection in signal level, therefore drive electrode only need share same lead-out wire.Annulus capacitor cell group is connected with sensor-based system signal processor by a lead-out wire with the drive electrode of strip capacitor cell group, each annulus of described annulus capacitor cell group goes between separately and to be connected with sensor-based system signal processor, sensor-based system signal processor calculates according to the output valve independent assortment of each annulus, carry out being averaging the size and normal force size that draw tangential force afterwards, when required precision is not high, annulus capacitor cell group can only select two optimum annulus to draw 2 lead-in wires, obtains d by these two annulus _xand d _n, thus draw size and the normal force size of tangential force; X-direction differential capacitor unit group and Y-direction differential capacitor unit group are drawn each via a lead-out wire respectively and are connected with sensor-based system signal processor, for calculating the direction of tangential force.Be provided with intermediate translator between described sensor-based system signal processor and capacitor cell, changer is for arranging voltage or frequency to the transmission coefficient of electric capacity.Whole capacitance component has at least 7 pins and draws from the side of planar package, so that whole assembly top and bottom outer surface can contact with measuring object easily.

The present invention, under the support of new material and new technology, completes the design of a kind of novel three-dimensional power sensitization capacitance combination.At 10 × 10mm ²stress surface on, be no matter normal direction or tangential, all can transmit stress more uniformly to medium.In the contact of non-coplanar force and sensor surface, external force only has 1, and can obtain the information of normal direction Fn to electric capacity summation, namely whole battery lead plate is all to asking Fn to contribute, and can obtain F again simultaneously _xand F _yinformation, thus complete description three-dimensional force, can improve the normal direction sensitivity and tangential sensitivity and maximum linear error once changed by design parameter.

By changing seat angle, seat is high, directly can measure man-vehicle system contact position (pedal, handlebar and vehicle seat) stressed, encoder on crank shaft can be followed the tracks of the angle between crank with pedal and measure synchronous with three-dimensional force, so just acts on effective force on pedal by calculating to try to achieve.By Microprocessor S3C44B0X synchronous light-emitting point, what realize that kinetic measurement and kinesiology test is synchronous, the kinematics and dynamics parameter of its test gained is together incorporated to bicycle and steps in juggling with the feet art diagnostic feedback systems soft ware, thus realizes data sampling and processing, storage and playback integration.

Above by reference to the accompanying drawings to invention has been exemplary description; obvious specific implementation of the present invention is not subject to the restrictions described above; as long as have employed the improvement of the various unsubstantialities that method of the present invention is conceived and technical scheme is carried out; or design of the present invention and technical scheme directly applied to other occasion, all within protection scope of the present invention without to improve.

Claims (10)

1. a cycling motion parameter collecting device, it is characterized in that, comprise pedal sensor, encoder and sensor system signals processor, encoder is arranged on the outer end of crank shaft, for obtain any time crank and pedal between angle β, solve the effective force along the axial inefficacious and vertical direction of crank, pedal transducer arrangements is on the left and right pedal of test carriage, obtain the three-dimensional force acted on pedal, described pedal sensor comprises annulus capacitor cell group and strip capacitor cell group, described strip capacitor cell group is arranged on the corner of the outer substrate of annulus capacitor cell group, annulus capacitor cell group comprises two to above annulus capacitor cell pair, described annulus capacitor cell is to comprising two annulus capacitor cells, described strip capacitor cell group comprises X-direction differential capacitor unit group and Y-direction differential capacitor unit group, X-direction differential capacitor unit group and Y-direction differential capacitor unit group include two or more and mutually form differential capacitor cell module, the comb teeth-shaped structure that described capacitor cell module is made up of plural strip capacitor cell, each annulus capacitor cell and strip capacitor cell include the drive electrode of top crown and the induction electrode of bottom crown.

2. cycling motion parameter collecting device according to claim 1, it is characterized in that, described supplemental training device also comprises handlebar sensor and vehicle seat sensor, for monitoring the three-dimensional active force on vehicle seat and handlebar, obtain the distribution of weight of upper body and the firmly feature of trunk-hand arm system.

3. cycling motion parameter collecting device according to claim 2, it is characterized in that, the induction electrode of described each annulus capacitor cell and drive electrode just to and shape is identical, the drive electrode of described each strip capacitor cell is identical with induction electrode width, the drive electrode length of strip capacitor cell is greater than induction electrode length, the drive electrode length two ends reserved left poor position δ respectively of strip capacitor cell _leftwith right poor position δ _right, b _{0 drives}=b _{0 sense}+ δ _right+ δ _left, wherein b _{0 drives}for the drive electrode length of strip capacitor cell, b _{0 sense}for the induction electrode length of strip capacitor cell.

4. cycling motion parameter collecting device according to claim 3, is characterized in that, the left poor position δ of described strip capacitor cell _left=right poor position δ _right, and wherein d ₀for elastic fluid thickness, G is the modulus of rigidity of elastic fluid, τ _maxfor maximum stress value.

5. cycling motion parameter collecting device according to claim 2, it is characterized in that, described two groups of drive electrodes mutually forming the strip capacitor cell of differential capacitor cell module and induction electrode are provided with the skew that initially misplaces in the width direction, and dislocation bias size is identical, direction is contrary.

6. cycling motion parameter collecting device according to claim 2, is characterized in that, described annulus capacitor cell group comprises n donut capacitor cell, wherein wherein, a _flatfor the length of parallel-plate, r _circlefor the width of annulus capacitor cell annulus, a _{δ circle}electrode spacing between adjacent two annulus capacitor cells.

7. cycling motion parameter collecting device according to claim 2, is characterized in that, X-direction differential capacitor unit group and Y-direction differential capacitor unit group include m strip capacitor cell, wherein, a _flatfor the length of parallel-plate, a _{δ bar}for the electrode spacing between adjacent two strip capacitor cells, a ₀the width of strip capacitor cell.

8. cycling motion parameter collecting device according to claim 2, is characterized in that, the width r of described donut capacitor cell _circlewith the width a of strip capacitor cell ₀equal; Strip capacitor cell electrode spacing a _{δ bar}with annulus capacitor cell electrode spacing a _{δ circle}equal, the width of described strip capacitor cell wherein, d ₀for elastic fluid thickness, E is the Young's modulus of elastic fluid, and G is the modulus of rigidity of elastic fluid.

9. cycling motion parameter collecting device according to claim 2, it is characterized in that, described annulus capacitor cell group is connected with sensor-based system signal processor by a lead-out wire with the drive electrode of strip capacitor cell group, the induction electrode of each annulus capacitor cell of described annulus capacitor cell group goes between separately and to be connected with sensor-based system signal processor, and described X-direction differential capacitor unit group is connected with sensor-based system signal processor respectively by a lead-out wire with the capacitor cell module induction electrode of Y-direction differential capacitor unit group.

10. cycling motion parameter collecting device according to claim 2, it is characterized in that, described annulus capacitor cell, be respectively equipped with intermediate translator between capacitor cell module and sensor-based system signal processor, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.