CN104965962A - Device for monitoring static friction force of cable meter counter - Google Patents

Abstract

The invention relates to a device for monitoring the static friction force of a cable meter counter. The device comprises meter counting wheels, a cable drawing machine, two-dimensional force sensors and a sensing system signal processor. The two-dimensional force sensors are arranged on the curved surfaces of the meter counting wheels and used for collecting the positive pressure and the static friction force between a cable and the meter counting wheels, sending the positive pressure and the static friction force to the sensing system signal processor and then feeding the positive pressure and the static friction force back to the cable drawing machine. Each sensor comprises an X-direction capacitor cell set and a Y-direction capacitor cell set. Each capacitor cell set is of a comb-tooth-shaped structure composed of at least two strip-shaped capacitor cells. Each strip-shaped capacitor comprises a driving electrode serving as an upper pole plate and an induction electrode serving as a lower pole plate. Each capacitor cell set comprises a first strip-shaped capacitor cell module composed of strip-shaped capacitor cells with the width a0 and the length b0 and a second strip-shaped capacitor cell module composed of strip-shaped capacitor cells with the width ka0 and the length b0. By means of the monitoring device, the positive pressure and the static friction force between the meter counting wheels and the cable are monitored in real-time, the phenomenon that as the positive pressure is excessively small, the provided maximum static friction force is insufficient is avoided, and meter counting errors caused when sliding friction is caused by the excessively-large drawing force are also avoided.

Description

A kind of cable meter counter stiction monitoring device

Technical field

The invention belongs to cable manufacturing industry technical field, relate to a kind of cable meter counter, be specifically related to a kind of cable meter counter stiction monitoring device.

Background technology

Meter counter is one of equipment of cable manufacturing indispensability, updating and improving along with equipment and product, meter-measuring device reasonable, precisely also more and more paid close attention to by manufacturer and research unit and paid attention to.The work that relevant meter counter reduces error of meter counter aspect is the work that line cable industry manufacturer extremely pays close attention to, especially to being worth (added value) high product, power cable as large in sectional area, control cable, mine cable, crosslinked cable and telecommunication cable etc. are all the more so.It is different that cable (is namely tightening with under relaxed state) metering measured value under different tension states, therefore measurement can produce certain error (deviation) in this case.Therefore, the tension force needing cable self to keep certain as far as possible in process of production.Whether the stretching pulley of meter counter, the tension force of mechanical pinch roller and colour band meter counter guide wheel skid in the manufacturing, are also the key factors affecting meters counting accuracy.In the production and application process of reality, the coiling speed of cable drawing machine, directly have influence on the friction force size of rice counting wheel or metering crawler belt and cable, in the process of cable metering, traction engine drives cable to travel forward, two rice counting wheels pressed against cable, drive rice counting wheel to rotate, realize metering function by the stiction between rice counting wheel and cable.

If the pressure of rice counting wheel and cable is too small, can cause the maximum static friction force that provides can not the tractive force of balance traction machine, become sliding friction by original static friction between rice counting wheel and cable, cause error of meter counter.If pressure is excessive, then traction engine must provide enough large tractive force that cable could be driven to move, and increases the energy loss of traction engine.Therefore, must monitor the malleation between meter counter and cable and stiction, guarantee that tractive force is also the maximum static friction force that stiction is no more than between rice counting wheel and cable, prevent from occurring sliding friction between cable and rice counting wheel, cause error of meter counter.

Summary of the invention

In order to overcome above the deficiencies in the prior art, the invention provides a kind of cable meter counter stiction monitoring device, by arranging 2 D force sensor on rice counting wheel, malleation between monitoring rice counting wheel and cable and tangential tractive force, prevent from occurring sliding friction between cable and rice counting wheel, cause error of meter counter.

Technical scheme of the present invention is: a kind of cable meter counter stiction monitoring device, comprise rice counting wheel and cable drawing machine, also comprise 2 D force sensor and sensor-based system signal processor, the curved surface that 2 D force sensor is arranged on rice counting wheel gathers normal pressure between cable and rice counting wheel and stiction and sends to sensor-based system signal processor, normal pressure and stiction are fed back to cable drawing machine by sensor-based system signal processor, 2 D force sensor comprises X-direction capacitor cell group and Y-direction capacitor cell group, described X-direction capacitor cell group and Y-direction capacitor cell group include capacitor cell module, the comb teeth-shaped structure that described capacitor cell module is made up of plural strip capacitor cell, each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown, described capacitor cell module comprises by two or more width a ₀length b ₀strip capacitor cell composition the first strip capacitor cell group and two or more width ka ₀length b ₀strip capacitor cell composition the second strip capacitor cell group.

The drive electrode of described each strip capacitor cell is identical with induction electrode width, and the length of drive electrode is greater than induction electrode length, and drive electrode length two ends are reserved left poor position δ respectively _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.Described poor position δ _left=δ _right, and wherein d ₀for strip capacitor cell dielectric thickness, G is the modulus of rigidity of elastic medium, τ _maxfor maximum stress value.The lead-in wire that described comb teeth-shaped structure comprises more than 20 strip capacitor cells, connects one to one with strip capacitor cell, is provided with electrode separation a between adjacent two strip capacitor cells _δ.Described parallel-plate area S=M (a ₀+ 2a _δ+ ka ₀) b ₀/ 2, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell.The strip capacitor cell lead-in wire of described first strip capacitor cell group and the second strip capacitor cell group is by parallel way or be independently connected to sensor-based system signal processor.The width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young modulus of elastic medium, and G is the modulus of rigidity of elastic medium.Described first strip capacitor cell group and be respectively equipped with intermediate translator between the second strip capacitor cell group 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 invention has the beneficial effects as follows: the present invention is on the basis passing through capacitance measurement three-dimensional force, the dull and stereotyped useful area of effective use, and be coupled by driving the methods such as pole plate two ends length in reserve effectively to solve between three-dimensional force, thus make normal direction and tangential conversion all reach higher linear, precision and sensitivity.In addition, to the malleation between rice counting wheel and cable and stiction Real-Time Monitoring, avoid the too small maximum static friction force that provides of malleation not enough, also avoid that tractive force is excessive causes sliding friction, cause error of meter counter.

Accompanying drawing explanation

Fig. 1 is strip capacitor cell and the coordinate system thereof of the specific embodiment of the present invention.

Fig. 2 is the strip capacitor cell schematic diagram of the specific embodiment of the present invention.

Fig. 3 is the strip capacitor cell dextrad skew schematic diagram of the specific embodiment of the present invention.

Fig. 4 is the strip capacitor cell left-hand skew schematic diagram of the specific embodiment of the present invention.

Fig. 5 is the width of the specific embodiment of the present invention is a ₀and ka ₀electric capacity to stressed deflection graph.

Fig. 6 is the parallel-plate three-dimensional force pressure sensor structure figure of the specific embodiment of the present invention.

Fig. 7 is the signal schematic representation that the cell capacitance of the specific embodiment of the present invention is right.

Fig. 8 is the plane-parallel capacitor cross-section structure 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 medium.

Embodiment

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 principle of work, 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.

Main thought of the present invention is: cable is in the process of metering, drawn by traction engine, cable passes in the middle of two rice counting wheels or crawler belt, and rice counting wheel applies pressure to cable, stiction between cable and rice counting wheel drives rice counting wheel to rotate, and realizes length metering.If the pressure between rice counting wheel and cable is too small, then maximum static friction force is less, easily sliding friction is there is between cable and rice counting wheel, cause error of meter counter, if pressure is excessive, can increase the stiction between cable and rice counting wheel, rice counting wheel is contrary with tractive force direction to the stiction direction of cable, affect the work efficiency of traction engine, the efficiency of whole production line also can be made to reduce.Therefore, the present invention arranges 2 D force sensor on the curved surface of rice counting wheel and cable contact, and the malleation of monitoring rice counting wheel and cable and tangential stiction, rationally arrange the malleation size of rice counting wheel and cable, and the haulage speed of cable drawing machine.At the outside surface of 2 D force sensor, one deck fexible film is set; play the effect of protection sensor; 2 D force sensor connects sensor-based system signal processor; sensor-based system signal processor carries out analyzing and processing to data; provide the tangential force between rice counting wheel and cable and normal force, 2 D force sensor of the present invention is the capacitance pressure transducer, of circular ring type.The stiction that cable drawing machine feeds back according to sensor-based system signal processor and normal pressure numerical value, regulate tractive force.

The measuring principle of three-dimensional force sensor of the present invention is below described: if Fig. 4-6 is the electrode plate structure figure of pressure transducer of the present invention, a kind of contact parallel-plate three-dimensional force pressure transducer, described sensor comprises X-direction capacitor cell group and Y-direction capacitor cell group, described X-direction capacitor cell group and Y-direction capacitor cell group include capacitor cell module, described capacitor cell module adopts the comb teeth-shaped structure be made up of plural strip capacitor cell, and each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown.Described capacitor cell module comprises by two or more width a ₀length b ₀first strip capacitor cell group of strip capacitor cell composition and two or more width ka ₀length b ₀second strip capacitor cell group of strip capacitor cell composition.The drive electrode of described each strip capacitor cell is identical with induction electrode width, and the length of drive electrode is greater than induction electrode length, and drive electrode length two ends are reserved left poor position δ respectively _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.Described poor position δ _left=δ _right, and wherein d ₀for dielectric thickness, G is the modulus of rigidity of elastic medium, τ _maxfor maximum stress value.The lead-in wire that described comb teeth-shaped structure comprises more than 20 strip capacitor cells, connects one to one with strip capacitor cell, is provided with electrode separation a between adjacent two strip capacitor cells _δ.Described parallel-plate area S=M (a ₀+ 2a _δ+ ka ₀) b ₀/ 2, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell.The strip capacitor cell lead-in wire of described first strip capacitor cell group and the second strip capacitor cell group is by parallel connection or be independently connected to sensor-based system signal processor.The width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young modulus of elastic medium, and G is the modulus of rigidity of elastic medium.Described first strip capacitor cell group and be provided with intermediate translator between the second strip capacitor cell group and sensor-based system signal processor, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.

1, the conversion characteristic of strip capacitor cell

(1) pumping signal and coordinate system

Strip capacitor cell is placed in the rectangular coordinate system shown in Fig. 1, pole plate plane length b ₀, width a ₀, dielectric thickness d ₀.Three-dimensional simulation puts on the outside surface of capacitor plate, and the contact acting force of generation 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, can output capacitance respond between the lead-in wire of electrode; Normal stress σ _n=Fn/A, wherein A=a ₀b ₀for pole plate normal direction stress surface, Fn=Fz is normal component; Both side surface produces paired tangential stress τ _x=Fx/A, τ _y=Fy/A.

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

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

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

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

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

(2) capacitance equation and input-output characteristic thereof

The initial capacitance of strip capacitor cell is:

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

In formula, ε ₀vacuum medium electric constant is 8.85PF/m, ε _r=2.5 is dielectric relative dielectric constant.D ₀by σ _nexcitation produce relative deformation substitute into (4) and obtain input-output characteristic

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

(3) linearity under normal stress effect and sensitivity

A, the normal direction linearity

F in (5) formula _nin the denominator, therefore C _n=f (F _n) relation be nonlinear, because of conversion range in maximal value σ _nmaxcompared with dielectric resilient constant E, ε _na very little amount, i.e. ε in denominator _n<<1, (5) are omitted the higher-order shear deformation of more than quadratic power by series expansion, and (5) formula can be reduced to:

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

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

B, sensitivity

By the definition of normal direction sensitivity

Can linear sensitivity be obtained by (6) formula,

$S_{n1}=C_0/AE={\mathrm{\&epsiv;}}_0{\mathrm{\&epsiv;}}_r/d_{0}E---\left(7\right)$

By (5) formula then

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

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

(4) tangential stress τ _xand τ _ycapacitance variations under excitation

Tangential stress τ _xand τ _ydo not change the physical dimension parameter b of pole plate ₀and a ₀, to dielectric thickness d ₀also do not have an impact.But τ _xand τ _ychange the space structure of strip capacitor cell, between the upper bottom crown faced by forward, there occurs dislocation skew.Now for OX direction, pole plate is at τ _xdislocation skew δ under effect _x.

Work as τ in fig. 2 _xwhen being zero, a _{on 0}=a _{0 time}just right, free area A between substrate _τ=a ₀b ₀; In figure 3, at τ _xunder the effect of dextrad, top crown creates dislocation skew δ to the right relative to bottom crown _x, thus make the useful area A between bottom crown when calculating electric capacity _τ=(a ₀-δ _x) b ₀; In Fig. 4, work as τ _xduring for left-hand, dislocation skew δ _xthen left, A _τ=(a ₀-δ _x) b ₀, τ _xwhen left-hand and dextrad, the reduction of useful area is identical, and consequent electric capacity is:

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

According to shearing Hooke's law

${\mathrm{\&tau;}}_x={\mathrm{\&gamma;}}_x\&CenterDot;G=G\&CenterDot;{\mathrm{\&delta;}}_x/d_0---\left(10\right)$

(10) are substituted into (9) can obtain

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

(11) formula is the input-output characteristics under shearing stress, C _τwith τ _xlinear.

And its sensitivity

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

The similar analysis in formula (9)-(12) is suitable for and τ equally _ywith C _{τ y}characteristic and technical indicator, the only long limit b of strip capacitor cell in formula ₀oX direction of principal axis should be arranged at, and its minor face a ₀then in OY direction.

2, contact parallel plate capacitor design

(1) planar design of parallel plate capacitor

The original index normal direction Max.contact stress σ of setting _nmaxfor 200Kpa, if the stressed A of normal direction is square 10 × 10mm ², then maximum normal force F _zmaxfor σ _nmaxa=20N.Tangential Max.contact stress τ _maxfor 70Kp, the distribution of force face of tangential stress is 10 × 10mm ², then maximum tangential force component F _xmax=F _ymax=τ _maxa=7N.

Strip capacitor cell constructive variations shown in Fig. 3 and Fig. 4, only illustrates that electric capacity exports and tangential stress ± τ _xthe relation of input, capacitance increase is all negative, and therefore this initial capacitance structure is not suitable for as right ± τ _xobtain the response increasing and decreasing electric capacity.The present invention adjusts the initial configuration of bottom crown on strip capacitor cell for this reason, and width is a ₀and ka ₀strip capacitor cell form a pair capacitor cell to (C _lwith C _r), specifically as shown in Figure 5.

In Fig. 5, capacitor cell C _land C _relectrode size b ₀, d ₀all identical, width one is a ₀, one is ka ₀, wherein k is constant, is preferably greater than the integer of 1.Work as τ _xwhen=0, C _l=C ₀, C _r=kC ₀, on this basis as at F _xδ is produced under excitation _xmistake skew, offset effect as shown in figure 3 or 4 will be formed.

$C_L=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0\&CenterDot;(a_0-{\mathrm{\&delta;}}_x)}{d_0}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0{\mathrm{\&tau;}}_x}{G}=C_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r{F}_x}{{\mathrm{Ga}}_0}---\left(13\right)$

$C_R=\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0\&CenterDot;({\mathrm{Ka}}_0-{\mathrm{\&delta;}}_x)}{d_0}={\mathrm{kC}}_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r\&CenterDot;b_0{\mathrm{\&tau;}}_x}{G}={\mathrm{kC}}_0-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r{F}_x}{{\mathrm{Ga}}_0}---\left(14\right)$

C _land C _rcapacitor cell is at same τ _xδ will be produced _xwith Δ C _τresponse.

Thus, formula (11) can be revised as

$C_{\mathrm{\&tau;}x}=C_{\mathrm{\&tau;}0}-\frac{{\mathrm{\&epsiv;}}_0\&CenterDot;{\mathrm{\&epsiv;}}_r}{{\mathrm{Ga}}_0}{F}_x$

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

Electrode plane see Fig. 6 is arranged, at a 10 × 10mm ²substrate center do cross separate, form four quadrants, upper right first quartile I, upper left second quadrant II, lower-left third quadrant III, bottom right fourth quadrant IV, wherein I, III quadrant is to τ _xmake the capacitor cell combination of response, and II, IV quadrant is to τ _ymake the capacitor cell combination of response.Object-line is 10 × 10mm ²pcb board four edge lines, hachure part represents the outer mode cross section of wax-loss casting process.Using 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.In figure, four dashed rectangle are the benchmark of induction electrode on bottom crown, put they and geometry datum line differential apart from being δ ₀(0.1mm).

Capacitor cell module adopts comb structure, and capacitor cell module adopts the comb teeth-shaped structure be made up of plural strip capacitor cell, and each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown.By formula (12) a ₀less, the sensitivity of tangential stress response is larger, therefore single capacitor cell is strip.If every root strip capacitor cell is wide is a ₀, the groove width between two strip electric capacity is a _δ, then the pitch of every root strip capacitor cell is ka ₀+ a ₀+ 2a _δ.In order to make full use of the plane space of square substrate, M (ka ₀+ a ₀+ 2a _δ) b ₀/ 2 ≈ 1 square substrate surface areas, M is strip electric capacity quantity, then have M (ka ₀+ a ₀+ 2a _δ)=20mm, in formula, groove width a _δunsuitable excessive, otherwise be unfavorable for using the effective plane space on substrate, also unsuitable too small, the constraint of wax-loss casting process is subject to.For making normal direction sensitivity S _nwith tangential sensitivity S _τequal, by formula (7) and (12), make a ₀g=d ₀e, works as d ₀when=0.1mm, k=1.5, thus M can be obtained.

In order to realize τ _xand τ _yrespond between tangential and mutually do not have an impact, the drive electrode length two ends reserved difference position δ of strip capacitor cell ₀, therefore b _{0 drives}=b _{0 end}+ 2 δ ₀, wherein at b _{0 drives}two ends length reserved difference potential theory should ensure its calculated value 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 should b be ensured in technique _{0 drives}-b _{0 end}>=0.01mm.

In order to realize τ _xand τ _ydo not produce any impact to the response of normal direction electric capacity, width is a ₀and ka ₀strip capacitor cell form a pair capacitor cell to (C _lwith C _r) carry out publicity reckoning elimination impact each other.Ensure τ _xproduce τ at I, III quadrant capacitor cell _xelectric capacity response, then produce τ at II, IV quadrant capacitor cell _yelectric capacity response, to ensure that capacitor cell in four quadrants is at τ _xand τ _ytwo groups of differential capacitors pair can be produced under tangential excitation.

(2) calculating of normal stress and tangential force

If width is a in Fig. 6 ₀strip capacitor cell be subject to tangential force τ _x, produce a tangential displacement d _xafter output capacitance value be C ₁, width is ka ₀strip capacitor cell be subject to tangential force τ _x, produce a tangential displacement d _xafter output capacitance value be C ₂, then have:

$C_1=\frac{\mathrm{\&epsiv;}(a_0-d_x)b_0}{d_n}=\frac{{\mathrm{\&epsiv;a}}_0{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;b}}_0{d}_x}{d_n}---\left(15\right)$

$C_2=\frac{\mathrm{\&epsiv;}({\mathrm{ka}}_0-d_x)b_0}{d_n}=\frac{{\mathrm{\&epsiv;ka}}_0{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;b}}_0{d}_x}{d_n}---\left(16\right)$

Obtained by (15)-(16):

$C_1-C_2=\frac{{\mathrm{\&epsiv;a}}_0{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;ka}}_0{b}_0}{d_n}$ Calculate

$d_n=\frac{{\mathrm{\&epsiv;a}}_0{b}_0(1-k)}{C_1-C_2}---\left(17\right)$

Obtained by (15) * k-(16):

${\mathrm{kC}}_1-C_2=\frac{{\mathrm{\&epsiv;d}}_x{b}_0}{d_n}-\frac{{\mathrm{\&epsiv;kd}}_x{b}_0}{d_n}=\frac{{\mathrm{\&epsiv;d}}_x{b}_0(1-k)}{d_n},$ (17) are substituted into above formula, can obtain:

$d_x=\frac{a_0({\mathrm{kC}}_1-C_2)}{C_1-C_2}--\left(18\right)$

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

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

By $\frac{d_x}{d_0}=\mathrm{\&gamma;}=\frac{\mathrm{\&tau;}}{G}=\frac{F_{\mathrm{\&tau;}}}{G\&CenterDot;S_0},$ So $F_{\mathrm{\&tau;}x}=\frac{{\mathrm{GS}}_0{d}_x}{d_0}.$

In above formula, no matter be normal direction excitation F _nor tangentially encourage F _yall not to O _τhave an impact.Namely automatically σ is eliminated _nand τ _yto τ _xthe coupling of total output or interference comprise at signal because every in the computing of subtracting each other, equivalent and the capacitance variations with symbol are eliminated all automatically.And F _yand F _xto σ _ninterference by upper electrode at b ₀direction increases geometrical length 2 δ ₀eliminate.In like manner F can be obtained _{τ y}.

(4) main material selection and characterisitic parameter thereof

The section of structure of comb teeth-shaped plane-parallel capacitor is similar to the sandwich structure shown in Fig. 8.In Fig. 8,1 is upper PCB substrate, and 2 is lower PCB substrate, and 3 is drive electrode, and 4 is induction electrode, and 5 is elastic medium.Pole plate is apart from d ₀=0.1mm, upper and lower base plate inner space, except copper foil electrode, is PDMS (dimethyl silicone polymer) the superlastic insulating medium with lost wax process filling.Its machinery and physical characteristics parameter are Young 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.

(5) contact conductor design

Be that drive electrode or induction electrode all need to have extension line, consider that each drive electrode is all ground connection in signal level, therefore four groups of drive electrodes only need share same extension line.The induction electrode of four the first strip capacitor cell groups and the second strip capacitor cell group then needs with respective independently extension line, and draw from the side of planar package so whole capacitance component has at least 5 pins, four induction electrodes refer to that X-direction width is a ₀induction electrode and width be ka ₀induction electrode, and Y-direction width is a ₀induction electrode and width be ka ₀induction electrode so that whole assembly top and bottom outside 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 literary composition, four cell capacitance are two to combination distribution.In the contact of non-coplanar force and sensor surface, external force only has 1, and electric capacity response but has 4, and whole battery lead plate, all to asking Fn to contribute, simultaneously by two pairs of capacitor combinations composition systems, can obtain F again _xand F _yinformation, thus complete description three-dimensional force.

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 (8)

1. a cable meter counter stiction monitoring device, comprise rice counting wheel and cable drawing machine, it is characterized in that, also comprise 2 D force sensor and sensor-based system signal processor, the curved surface that 2 D force sensor is arranged on rice counting wheel gathers normal pressure between cable and rice counting wheel and stiction and sends to sensor-based system signal processor, normal pressure and stiction are fed back to cable drawing machine by sensor-based system signal processor, 2 D force sensor comprises X-direction capacitor cell group and Y-direction capacitor cell group, described X-direction capacitor cell group and Y-direction capacitor cell group include capacitor cell module, the comb teeth-shaped structure that described capacitor cell module is made up of plural strip capacitor cell, each strip capacitor cell comprises the drive electrode of top crown and the induction electrode of bottom crown, described capacitor cell module comprises by two or more width a ₀length b ₀strip capacitor cell composition the first strip capacitor cell group and two or more width ka ₀length b ₀strip capacitor cell composition the second strip capacitor cell group.

2. cable meter counter stiction monitoring device according to claim 1, it is characterized in that, the drive electrode of described each strip capacitor cell is identical with induction electrode width, and the length of drive electrode is greater than induction electrode length, and drive electrode length two ends are reserved left poor position δ respectively _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.

3. cable meter counter stiction monitoring device according to claim 2, is characterized in that, described poor position δ _left=δ _right, and wherein d ₀for strip capacitor cell dielectric thickness, G is the modulus of rigidity of elastic medium, τ _maxfor maximum stress value.

4. cable meter counter stiction monitoring device according to claim 1, it is characterized in that, the lead-in wire that described comb teeth-shaped structure comprises more than 20 strip capacitor cells, connects one to one with strip capacitor cell, is provided with electrode separation a between adjacent two strip capacitor cells _δ.

5. cable meter counter stiction monitoring device according to claim 4, is characterized in that, described parallel-plate area S=M (a ₀+ 2a _δ+ ka ₀) b ₀/ 2, wherein, M is strip capacitor cell quantity, b ₀for the length of strip capacitor cell, a ₀the width of strip capacitor cell.

6. cable meter counter stiction monitoring device according to claim 1, it is characterized in that, the strip capacitor cell lead-in wire of described first strip capacitor cell group and the second strip capacitor cell group is by parallel way or be independently connected to sensor-based system signal processor.

7. cable meter counter stiction monitoring device according to claim 1, is characterized in that, the width of described strip capacitor cell wherein, d ₀for dielectric thickness, E is the Young modulus of elastic medium, and G is the modulus of rigidity of elastic medium.

8. cable meter counter stiction monitoring device according to claim 1, it is characterized in that, described first strip capacitor cell group and be respectively equipped with intermediate translator between the second strip capacitor cell group and sensor-based system signal processor, intermediate translator is for arranging voltage to electric capacity or frequency to the transmission coefficient of electric capacity.