CN102252740A - Vehicle dynamic weighing sensor - Google Patents

Abstract

The invention discloses a vehicle dynamic weighing sensor. The vehicle dynamic weighing sensor comprises an optical fiber microbend-elastic oil pipe sensor, an optical fiber raster-hydraulic sensor, first transmission optical fiber, second transmission optical fiber, third transmission optical fiber, fourth transmission optical fiber, a light intensity demodulation module, an optical wavelength demodulation module and a restrictor valve, wherein laser emitted by the light intensity demodulation module is introduced from the first transmission optical fiber to the optical fiber microbend-elastic oil pipe sensor and then is led out by the second transmission optical fiber to the light intensity demodulation module; laser emitted by the optical wavelength demodulation module is introduced from the third transmission optical fiber to the optical fiber raster-hydraulic sensor and then is led out by the fourth transmission optical fiber to the optical wavelength demodulation module; at least one overflow hole is formed in the restrictor valve; and the optical fiber microbend-elastic oil pipe sensor is communicated with the optical fiber raster-hydraulic sensor through the restrictor valve. The vehicle dynamic weighing sensor has high anti-electromagnetic interference capacity, measurement accuracy and high durability, is convenient to carry and realizes remote monitoring easily.

Description

A kind of vehicle dynamic LOAD CELLS

Technical field

The present invention relates to a kind of vehicle dynamic LOAD CELLS, be mainly used in the dynamic information collection of travels down vehicle.

Background technology

Along with the development of national economy and highway communication cause, the road transport network of China is flourishing day by day, and the number of highway bridge is also increasing.As time goes on, owing to the reason such as aging of the change of environment, bridge, the permanance of bridge structure, reliability be decay gradually also.Therefore, bridge structure is carried out health monitoring in total life cycle, very necessary and significant.Wherein, vehicular load is as one of of paramount importance load of bridge structure, and the validity of collecting vehicle information and accuracy are very outstanding for the fiduciary level of judging bridge structure and the effect of residual life phase.Moreover, the vehicle weight information of accurately grasping on the arterial highway also has crucial meaning for the planning of the network of highways in the zone and the maintenance of existing road.

For weighing of vehicle, traditional method all is to measure under static state, requires vehicle to be in halted state, and method of testing is very big to the influence of traffic, is not suitable for the weight information that detects vehicle on the arterial highway.Therefore, since nearly half a century, many countries all are devoted to the automobile dynamically weighing technology is studied, and have obtained certain achievement and corresponding product.Yet, traditional dynamic weighing sensor all is based on the measurement of electrical quantities and weighs, such sensor anti-electromagnetic interference capability is poor, repeatability is low, and the transmission of vehicle weight often relies on physical construction to carry out, and its sensitivity, validity often produce bigger error because of the variation of the inhomogeneous and material property of internal force.

Recent two decades comes, and along with the development of optical information technology, the optical information product price reduces gradually, and optical fiber sensing technology also obtains very big development.Than traditional dynamic measuring tech based on electrical quantities, Fibre Optical Sensor has advantages such as highly sensitive, anti-electromagnetic interference (EMI), corrosion-resistant, in light weight, little power consumption.

Summary of the invention

The purpose of this invention is to provide a kind of dynamic weighing sensor that can accurately measure the vehicle weight in travelling.

For solving the problems of the technologies described above, technical scheme of the present invention is:

A kind of vehicle dynamic LOAD CELLS comprises optical fiber micro-bending-elasticity pressure hose sensor, fiber grating-hydraulic pressure transducer, first Transmission Fibers, second Transmission Fibers, the 3rd Transmission Fibers, the 4th Transmission Fibers, light intensity demodulation module, optical wavelength demodulation module and excess flow valve; The laser that described light intensity demodulation module sends is introduced into optical fiber micro-bending-elasticity pressure hose sensor through first Transmission Fibers, through second Transmission Fibers laser is led to the light intensity demodulation module again; Described optical wavelength demodulation module emitted laser is introduced into fiber grating-hydraulic pressure transducer through the 3rd Transmission Fibers, through the 4th Transmission Fibers laser is led to the optical wavelength demodulation module again; Described excess flow valve is provided with at least one flowing hole, and optical fiber micro-bending-elasticity pressure hose sensor is communicated with fiber grating-hydraulic pressure transducer by excess flow valve.

Described optical fiber micro-bending-elasticity pressure hose sensor comprises base plate, elasticity oil pipe, optical fiber, viscoelasticity interlayer, cover plate; Described base plate is provided with cylindrical groove; Described elasticity oil pipe periphery longitudinally spiral is provided with optical fiber, and is positioned at cylindrical groove along the length direction of cylindrical groove; Described cover plate is located at elasticity oil pipe top; Be provided with one deck viscoelasticity interlayer at least between described base plate and the cover plate, the signal stabilization cycle of vibration when rolling sensor and shortening test to alleviate vehicle.

Also be provided with the protection pad between described cover plate and elasticity oil pipe; The material of described protection pad is preferably polyethylene foamed or rubber.

Described optical fiber is preferably and adopts high-intensity bonding agent longitudinal spiral to stick on elasticity oil pipe periphery.

Described cylindrical groove is preferably the cylindrical groove of edge concave-convex surface.

Described base plate is preferably the high-strength alloy base plate; The material of described oil pipe is preferably resilient material, more preferably elastic rubber material.Can restorable voluntarily material after jerk-finger of the present invention deforms.

Described fiber grating-hydraulic pressure transducer comprises hydraulic jack, plunger disc, piston rod, fiber Bragg grating strain sensor, and described hydraulic jack one end is communicated with the elasticity oil pipe by excess flow valve, and the other end is provided with first circular hole and second circular hole; Described plunger disc places in the hydraulic jack, and is connected by the end that piston rod and hydraulic jack are provided with circular hole, forms airtight connected space between plunger disc, hydraulic jack, excess flow valve and elasticity oil pipe, and is full of hydraulic oil; Described fiber Bragg grating strain sensor is located at piston rod side, and draws, introduces the optical wavelength demodulation module by first circular hole and second circular hole respectively by the 3rd Transmission Fibers, the 4th Transmission Fibers.

In order to guarantee to form between plunger disc, hydraulic jack, flowing hole and elasticity oil pipe the impermeability of confined space, also be provided with first packing washer between described compressing cylinder and excess flow valve; Also be provided with second packing washer between plunger disc and hydraulic jack.

Be preferably between described hydraulic jack and excess flow valve and be threaded.

For reducing the pressure loss in the hydraulic pressure transfer process, described hydraulic oil is preferably hydraulic pressure silicone oil.

The present invention is mounted to base plate on the monitoring car road surface when mounted, and remaining part carries out installation in position according to above-mentioned implementation.Optical fiber generation microbend when the present invention can utilize the vehicle process, the laser in the fiber core layer by the loss of luminous power and the linear relationship of vehicle weight, records the weight of vehicle because fiber optic microbend enters covering.

G＝α·V _ep (1)

In the formula, the G-vehicle weight;

V _Ep-back light strong solution mode transfer piece luminous power;

α-demarcation constant is obtained by on-site proving.

After the automobile warp, the elasticity oil pipe recovers original form, and optical fiber also resiles thereupon.

The present invention can also deform by elasticity oil pipe under vehicle weight, and hydraulic oil pressure increases, and by the linear relationship between liquid pressure and the vehicle weight, obtains the weight of vehicle.Because the selected hydraulic oil of the present invention can be ignored with respect to the pressure of hydraulic oil self at the formed pressure difference of difference, so hydraulic oil pressure value equates in the airtight connection cavity that forms between plunger disc, hydraulic jack, excess flow valve and elasticity oil pipe everywhere, the pressure that is the hydraulic oil in optical fiber micro-bending-elasticity pressure hose sensor and the fiber grating-hydraulic pressure transducer equates everywhere, by the linear relationship between piston rod strain and the liquid pressure, obtain the liquid pressure value, and then obtain the weight of vehicle.Concrete principle is as follows:

According to the mode coupling theory, the pass of fiber grating centre wavelength and fiber grating pitch is:

λ _B＝2n·Λ (2)

Wherein, λ _BIt is the reflection wavelength of fiber grating; N is the effective refractive index of fiber grating fibre core; Λ is the pitch of fiber grating.Optical fiber grating temperature, stress changes all can cause catoptrical centre wavelength to change, by the centre wavelength drift delta λ of fiber grating _BRelation with temperature variation Δ T and strain variation Δ ε:

$\frac{{\mathrm{\Δ\λ}}_B}{{\mathrm{\λ}}_B}-({\mathrm{\α}}_f+\mathrm{\ξ})\mathrm{\ΔT}+(1-P_e)\mathrm{\Δ\ϵ}---\left(3\right)$

Wherein,

Be the thermal expansivity of optical fiber,

Be the thermo-optical coeffecient of fiber optic materials,

Elasto-optical coefficient for fiber optic materials.

Fiber Bragg grating strain sensor is made up of strain sensing fiber grating and temperature compensation optical fiber grating, and the centre wavelength drift of establishing the strain sensor fibre grating is Δ λ _{B, ε}, the centre wavelength drift of temperature compensation optical fiber grating is Δ λ _{B, T}, then (3) formula of two fiber gratings is respectively:

$\frac{{\mathrm{\&Delta;\&lambda;}}_{B,\mathrm{\&epsiv;}}}{{\mathrm{\&lambda;}}_{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HDA0000056400100000011.png"\; state="\{\{state\}\}">B</figure-callout>}1}}=({\mathrm{\&alpha;}}_f+\mathrm{\&xi;})\mathrm{\&Delta;T}+(1-P_e)\mathrm{\&Delta;\&epsiv;}---(3-1)$

$\frac{{\mathrm{\&Delta;\&lambda;}}_{B,T}}{{\mathrm{\&lambda;}}_{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HDA0000056400100000011.png"\; state="\{\{state\}\}">B</figure-callout>}2}}=({\mathrm{\&alpha;}}_f+\mathrm{\&xi;})\mathrm{\&Delta;T}---(3-2)$

After two formulas are subtracted each other:

$\frac{{\mathrm{\&Delta;\&lambda;}}_{B,\mathrm{\&epsiv;}}}{{\mathrm{\&lambda;}}_{B1}}-\frac{{\mathrm{\&Delta;\&lambda;}}_{B,T}}{{\mathrm{\&lambda;}}_{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HDA0000056400100000011.png"\; state="\{\{state\}\}">B</figure-callout>}2}}=(1-P_e)\mathrm{\&Delta;\&epsiv;}---(3-3)$

Wherein, λ _B1, λ _B2Be respectively the initial wavelength of strain sensing fiber grating, the initial wavelength of temperature compensation optical fiber grating.

Linear relationship between piston rod and the liquid pressure changing value is:

Δε＝α ₁ΔP (4)

Wherein, α ₁Be constant, obtain by on-site proving.

Linear relationship between liquid pressure changing value and the vehicle weight is:

G＝α ₂ΔP (5)

Wherein, α ₂Be constant, obtain by on-site proving.

Formula (3-3), (4) are brought into formula (5) to get:

$G=\frac{\mathrm{\&beta;}}{1-P_e}(\frac{{\mathrm{\&Delta;\&lambda;}}_{B,\mathrm{\&epsiv;}}}{{\mathrm{\&lambda;}}_{B1}}-\frac{{\mathrm{\&Delta;\&lambda;}}_{B,T}}{{\mathrm{\&lambda;}}_{B2}})---\left(6\right)$

Wherein, β=α ₂/ α ₁Be calibration coefficient, obtain by on-site proving.

About the initial wavelength X of two fiber-optic grating sensors _B1And λ _B2Known, the elasto-optical coefficient P of fiber optic materials _eFor known, by the wave length shift Δ λ of detection fiber grating _B1With Δ λ _B2, then the weight of vehicle can get.

The present invention is staggered front to back the right and left that is arranged in the track center line with two vehicle dynamic LOAD CELLS in use, utilizes wheel to arrive the mistiming, sensor of two sensors distance in vehicle forward direction, can try to achieve the travel speed of vehicle; Utilize front and back wheel to arrive the mistiming of same sensor and the travel speed that records, try to achieve the wheelbase of vehicle.

The present invention carries out dynamic weighing with hydraulic system and optical fiber sensing technology combination to vehicle, has following beneficial effect: can measure many groups such as vehicle weight, speed, vehicle wheelbase parameter simultaneously; Adopt optical fiber micro-bending, fiber grating strain measuring technology, anti-electromagnetic interference capability is strong, the accuracy of measurement height; The electrical devices good endurance that the permanance of fiber sensing element is more traditional, long service life; Two working sensors are independent, do not disturb mutually, make The result of dynamic test more accurately with reliable; The sensor overall weight is light, and simple installation is easy to carry, can realize portable monitoring; The vehicle weight monitoring is easy to realize remote monitoring; Belong to the category of national intelligent transportation system, market is huge, has a extensive future.

Description of drawings

Fig. 1 is a structural representation of the present invention.

Fig. 2 is the structural representation of optical fiber micro-bending of the present invention-elasticity pressure hose sensor.

Fig. 3 is the side sectional view of Fig. 2 perpendicular to elasticity oil pipe direction.

Fig. 4 is the structural representation of fiber grating-hydraulic pressure transducer of the present invention.

Fig. 5 is the cut-open view of Fig. 4 along the A-A line.

Fig. 6 is the cut-open view of Fig. 4 along the B-B line.

Fig. 7 is the cut-open view of Fig. 4 along the C-C line.

Fig. 8 is the cut-open view of Fig. 4 along the D-D line.

Fig. 9 is the cut-open view of Fig. 4 along the E-E line.

Figure 10 is the cut-open view of Fig. 4 along the F-F line.

Figure 11 is that sensor of the present invention lays position view on the road surface.

Embodiment

Below in conjunction with accompanying drawing technical scheme of the present invention is elaborated.

Dynamic weighing sensor as shown in Figure 1 comprises optical fiber micro-bending-elasticity pressure hose sensor 1, fiber grating-hydraulic pressure transducer 2, first Transmission Fibers 3, second Transmission Fibers 4, the 3rd Transmission Fibers 5, the 4th Transmission Fibers 6, light intensity demodulation module 7, optical wavelength demodulation module 8 and excess flow valve 9; The laser that described light intensity demodulation module 7 sends is introduced into optical fiber micro-bending-elasticity pressure hose sensor 1 through first Transmission Fibers 3, through second Transmission Fibers 4 laser is led to light intensity demodulation module 7 again; Described optical wavelength demodulation module 8 emitted laser are introduced into fiber grating-hydraulic pressure transducer 2 through the 3rd Transmission Fibers 5, through the 4th Transmission Fibers 6 laser are led to optical wavelength demodulation module 8 again; Described excess flow valve 9 is provided with at least one flowing hole 9-1, and optical fiber micro-bending-elasticity pressure hose sensor 1 is communicated with fiber grating-hydraulic pressure transducer 2 by excess flow valve 9.

Above-mentioned optical fiber micro-bending-elasticity pressure hose sensor 1 as shown in Figures 2 and 3 comprises base plate 1-1, elasticity oil pipe 1-2, optical fiber 1-3, viscoelasticity interlayer 1-4, cover plate 1-5; Described base plate 1-1 is provided with cylindrical groove 1-1-1; Described elasticity oil pipe 1-2 periphery longitudinally spiral is adhesive with optical fiber 1-3, and is positioned at cylindrical groove 1-1-1 along the length direction of cylindrical groove 1-1-1; Described cover plate 1-5 is located at elasticity oil pipe 1-2 top, also is provided with protection pad 1-6 between cover plate 1-5 and elasticity oil pipe 1-2; Be provided with one deck viscoelasticity interlayer 1-4 at least between described base plate 1-1 and the cover plate 1-5.Cylindrical groove 1-1-1 is the cylindrical groove of edge concave-convex surface.The material of protection pad 1-6 is flexible polyethylene foamed or flexible rubber.The material of elasticity oil pipe 1-2 is a high elastic rubber.

Above-mentioned fiber grating-hydraulic pressure transducer 2 shown in Fig. 4 to 9 comprises hydraulic jack 2-1, plunger disc 2-2, piston rod 2-3, fiber Bragg grating strain sensor 2-4, described hydraulic jack 2-1 one end is communicated with elasticity oil pipe 1-2 by excess flow valve 9,9 of hydraulic jack 2-1 and excess flow valves are for being threaded, and the other end is provided with the first circular hole 2-1-1 and the second circular hole 2-1-2; Described plunger disc 2-2 places in the hydraulic jack 2-1, and be connected by the end that piston rod 2-3 and hydraulic jack 2-1 are provided with circular hole, form airtight connected space between plunger disc 2-2, hydraulic jack 2-1, excess flow valve 9 and elasticity oil pipe 1-2, and be full of hydraulic oil 1-2-1; Described fiber Bragg grating strain sensor 2-4 is located at piston rod 2-3 side, and draws, introduces optical wavelength demodulation module 8 by the first circular hole 2-1-1 and the second circular hole 2-1-2 respectively by the 3rd Transmission Fibers 5, the 4th Transmission Fibers 6.9 of described compressing cylinder 2-1 and excess flow valves are provided with the first packing washer 2-5; Be provided with the second packing washer 2-6 between plunger disc 2-2 and hydraulic jack 2-1.Described hydraulic oil 1-2-1 is a hydraulic pressure silicone oil.

As shown in figure 10, combined type car dynamic weighing sensor of the present invention is mounted to the monitoring lane position, when vehicle during through optical fiber micro-bending-elasticity pressure hose sensor 1, the optical fiber 1-3 on the elasticity that is laid in oil pipe 1-2 surface vehicle roll with cylindrical groove 1-1-1 acting in conjunction under bent forming takes place.Part light in the optical fiber 1-3 enters covering because of the optical fiber micro-bending distortion, and the light intensity decreasing of back light strong solution mode transfer piece 7 calculates vehicle weight by formula (1).

Also measuring vehicle weight by the following method: when vehicle during through optical fiber micro-bending-elasticity pressure hose sensor 1, the hydraulic oil 1-2-1 pressure in the elasticity oil pipe 1-2 increases because of vehicle rolls.Because the liquid pressure in the enclosed cavity equates everywhere, hydraulic oil 1-2-1 pressure in fiber grating-hydraulic pressure transducer 2 increases, hydraulic oil 1-4 pressure acts on plunger disc 2-2, axial crushing deformation takes place because of the constraint of hydraulic jack 2-1 in piston rod, the light intensity frequency values of fiber grating under compressive strain that sticks on piston rod side drifts about, by formula (6), calculate vehicle weight.

One group of dynamic weighing sensor of the present invention is mounted on the monitoring track by position shown in Figure 10, can realizes automobile axle load, complete vehicle weight, time of arrival, travel speed, the isoparametric measurement of wheelbase.With the diaxon four-wheel automobile is example, the time t that fibre strain was undergone mutation when the off-front wheel of meter automobile arrived the sensor on right side, track ₁, the time t that fibre strain was undergone mutation when off hind wheel arrived the sensor on right side, track ₂, the time t that optical fiber was undergone mutation when the near front wheel arrived the sensor in left side, track ₁', the time t that optical fiber was undergone mutation when a left side arrived the sensor in left side, track ₂'.Between the known sensor along vehicle traveling direction apart from s, automobile driving speed then: v=s/ (t ₁'-t ₁) or v=s/ (t ₂'-t ₂); The wheelbase of automobile is d=v (t ₂-t ₁) or d=v (t ₂'-t ₁').It is heavy that the forward and backward wheel load that adds up respectively promptly obtains the forward and backward axle of automobile, and each axle recuperation that adds up is to complete vehicle weight.

Claims (9)

1. a vehicle dynamic LOAD CELLS is characterized in that comprising optical fiber micro-bending-elasticity pressure hose sensor (1), fiber grating-hydraulic pressure transducer (2), first Transmission Fibers (3), second Transmission Fibers (4), the 3rd Transmission Fibers (5), the 4th Transmission Fibers (6), light intensity demodulation module (7), optical wavelength demodulation module (8) and excess flow valve (9); The laser that described light intensity demodulation module (7) sends is introduced into optical fiber micro-bending-elasticity pressure hose sensor (1) through first Transmission Fibers (3), through second Transmission Fibers (4) laser is led to light intensity demodulation module (7) again; Described optical wavelength demodulation module (8) emitted laser is introduced into fiber grating-hydraulic pressure transducer (2) through the 3rd Transmission Fibers (5), through the 4th Transmission Fibers (6) laser is led to optical wavelength demodulation module (8) again; Described excess flow valve (9) is provided with at least one flowing hole (9-1), and optical fiber micro-bending-elasticity pressure hose sensor (1) is communicated with fiber grating-hydraulic pressure transducer (2) by excess flow valve (9).

2. a kind of vehicle dynamic LOAD CELLS as claimed in claim 1 is characterized in that described optical fiber micro-bending-elasticity pressure hose sensor (1) comprises base plate (1-1), elasticity oil pipe (1-2), optical fiber (1-3), viscoelasticity interlayer (1-4), cover plate (1-5); Described base plate (1-1) is provided with cylindrical groove (1-1-1); Described elasticity oil pipe (1-2) periphery longitudinally spiral is provided with optical fiber (1-3), and is positioned at cylindrical groove (1-1-1); Described cover plate (1-5) is located at elasticity oil pipe (1-2) top; Be provided with one deck viscoelasticity interlayer (1-4) at least between described base plate (1-1) and the cover plate (1-5).

3. a kind of vehicle dynamic LOAD CELLS as claimed in claim 2 is characterized in that also being provided with between described cover plate (1-5) and elasticity oil pipe (1-2) protection pad (1-6).

4. as claim 2 or 3 described a kind of vehicle dynamic LOAD CELLS, it is characterized in that described cylindrical groove (1-1-1) is the cylindrical groove of edge concave-convex surface.

5. as claim 2 or 3 described a kind of vehicle dynamic LOAD CELLS, it is characterized in that optical fiber (1-3) longitudinal spiral sticks on elasticity oil pipe (1-2) periphery.

6. as claim 2 or 3 described a kind of vehicle dynamic LOAD CELLS, it is characterized in that described fiber grating-hydraulic pressure transducer (2) comprises hydraulic jack (2-1), plunger disc (2-2), piston rod (2-3), fiber Bragg grating strain sensor (2-4), described hydraulic jack (2-1) end is communicated with elasticity oil pipe (1-2) by excess flow valve (9), and the other end is provided with first circular hole (2-1-1) and second circular hole (2-1-2); Described plunger disc (2-2) places in the hydraulic jack (2-1), and be connected by the end that piston rod (2-3) and hydraulic jack (2-1) are provided with circular hole, form airtight connected space between plunger disc (2-2), hydraulic jack (2-1), excess flow valve (9) and elasticity oil pipe (1-2), and be full of hydraulic oil (1-2-1); Described fiber Bragg grating strain sensor (2-4) is located at piston rod (2-3) side, and draws, introduces optical wavelength demodulation module (8) by first circular hole (2-1-1) and second circular hole (2-1-2) respectively by the 3rd Transmission Fibers (5), the 4th Transmission Fibers (6).

7. a kind of vehicle dynamic LOAD CELLS as claimed in claim 6 is characterized in that being provided with first packing washer (2-5) between hydraulic jack (2-1) and excess flow valve (9); Be provided with second packing washer (2-6) between plunger disc (2-2) and hydraulic jack (2-1).

8. a kind of vehicle dynamic LOAD CELLS as claimed in claim 6 is characterized in that between hydraulic jack (2-1) and excess flow valve (9) for being threaded.

9. a kind of vehicle dynamic LOAD CELLS as claimed in claim 7 is characterized in that between hydraulic jack (2-1) and excess flow valve (9) for being threaded.

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