CN100562734C - The measuring method of tyre non-circularity - Google Patents

Abstract

The measuring method of tyre non-circularity of the present invention is measured and is demarcated at tire appearance profile parameter, intuitively and synthetically to detect the out-of-roundness index, offers the degree that processing quality department analyzes the tire geometry deformation.In the tire building process, the distortion and the tyre sidewall became uneven that have influence on tyre surface owing to belt cause tread projections and depression, foundation can reflect the tyre non-circularity because of material and manufacturing process formation, be embodied in the parameter that to examine in the tyre non-circularity testing process, include top lateral deviation, top radial missing, central radial missing, bottom radial missing, bottom lateral deviation, top bulge, top depression, bottom bulge and bottom notch value.

Description

The measuring method of tyre non-circularity

Technical field

The present invention relates to a kind of measuring method, a plurality of parameters that relate at tyre non-circularity are measured the method for demarcation specifically.

Background technology

Tire is that member is carried out in the main action of motor vehicles, and stablizing and whether meeting the Safety Design standard of tyre performance will directly determine to use the personal security of motor vehicles.Tire is the rotatable body of a kind of circular ring type of tubular section, and it is to be processed through applying, moulding, sulfuration typing by rubber preformed material, compounded rubber preformed material that multilayer has an all-steel cord.The tire of described structure, its constituent material exist density unevenness inevitably, problem such as geometric deformation, the just tyre non-circularity of often saying are arranged.According to relevant mechanics principle, there is the to a certain degree tire of distortion, under the high speed rotating situation, must produce radial force, the side force of alternation, thereby can cause the vibration or the noise of automobile, also can have influence on speed, comfort level or the smoothness of automobilism.

In the tire building process, if bubble is arranged between the belt, then the relevant position of surface of tyre has projection.If belt or wirecord fabric are discontinuous when tire building, or when sulfuration cure efficiency bad, cause the tyre sidewall became uneven at tire, these all will directly cause beating perpendicular to arbitrary cross sectional radius existence of tire center line, and promptly rising and falling appears in tyre surface and sidewall.Because tire sidewall is thinner than tyre surface,, when charging into pressure-air, tire has projection clearly if therefore there is bubble on the sidewall; In addition, belt lap-joint can be local thicker than other, thus intensity herein than other position height, when tire charged into elevated pressures, belt lap-joint had tangible depression, at tire sidewall, this phenomenon will be more obvious.More than about the phenomenon of tire geometric deformation, be referred to as the out-of-roundness of tire.

And existing the realization in tire production and the testing process, Shang Weiyou comprehensively and theoretical targetedly the support and concrete measuring method, therefore exist certain blindness for non-roundness measurement, lacking intuitively, test technology instructs, the testing equipment of tyre non-circularity is backward, testing result is unstable, and then has influence on the safety traffic of motor vehicles.

Summary of the invention

The measuring method of tyre non-circularity of the present invention, its purpose is to address the above problem and measures and demarcate at each parameter that produces and influence tyre non-circularity, intuitively and synthetically to detect the out-of-roundness index, offer tire technology, quality inspection, the degree of checking tire geometry deformation.

In the tire building process, the distortion and the tyre sidewall became uneven that have influence on tyre surface owing to belt cause tread projections and depression, and the present invention sets up following technical know-how support.

Can reflect because of the tyre non-circularity of material and manufacturing process formation, be embodied in the reference index that forms in the following tire checking process, include:

Beating of tire sidewall, this is the fluctuations of tire on surface, normal inflation lower sidewall;

The bulge of tire sidewall: bulge mainly causes owing to bubble.Because the sidewall is thin than tyre surface, the bubble that is in the sidewall will have very big influence to tire, if there is bubble to exist, is easy to cause tire in use to blow out;

The depression of tire sidewall: because the sidewall is thinner, the belt lap-joint that is in the sidewall can be obviously strong than other positions, sidewall, when tire charges into elevated pressures, the belt overlapping part on sidewall is because higher-strength is difficult by hyperbar jack-up, other positions, sidewall are because weak strength, then can expand under hyperbar, the belt lap-joint on sidewall can form tangible depression like this.This replenishes under the gaseity or tire can not form tangible depression under normal inflation at tire, and therefore, the depression on sidewall must be measured under higher charge pressure;

Beating of tire tire shoulder: the tire shoulder position of tire is to be made of multiple sizing material, and the tire shoulder position also is the edge of belt, cord, very easily exists and beats more greatly, and bubble also appears in tire shoulder position easily, therefore is necessary very much beating of tire shoulder detected;

Beating of tire tread: beating of tyre surface, directly caused inhomogeneity radial force fluctuation, if it is bigger to beat, the dynamic balance performance of tire also can be poor so.

At above-mentioned 5 main reference indexs, the measuring method of described tyre non-circularity is measured at following five positions of tire at least, is respectively:

The tire top side to: be used to measure top side to beat, top bump, top depression;

The tire top is radially: be used to measure beating of top tire shoulder;

Tire central authorities are radially: be used for beating of measuring wheel tire tread;

Tire bottom is radially: be used to measure beating of bottom tire shoulder;

The tire bottom side to: be used to measure bottom side to beat, bottom protrusion, bottom notch.

Use above-mentioned support theory, the measuring method of described tyre non-circularity, at above-mentioned generation and influence the factor of tyre non-circularity, test and calibrate the dimensional discrepancy value of tyre non-circularity successively, include top lateral deviation, top radial missing, central radial missing, bottom radial missing, bottom lateral deviation, top bulge, top depression, bottom bulge and bottom notch value.

Described top lateral deviation is poor in the maximal value of the lateral attitude size of sidewall, top tire and minimum value, that is sidewall, top the poor of the maximum of points of waveform and minimum point that beat;

Setting the top lateral deviation is TLRO, then TLRO=TL _Max-TL _Min, wherein,

TL _max＝max(TL(i))(i＝1，2…n)；

TL _min＝min(TL(i))(i＝1，2…n)；

TL (i) be top side to measured data, i=1,2 ... n;

Described top radial missing be radially locate the maximal value of tyre free radius and minimum value at the top poor, that is top diameter run-out waveform maximum of points and minimum point is poor;

Setting the top radial missing is TRRO, then TRRO=TR _Max-TR _Min, wherein,

TR _max＝max(TR(i))(i＝1，2…n)；

TR _min＝min(TR(i))(i＝1，2…n)；

TR (i) is a radially measured data of top, i=1,2 ... n;

Described central radial missing be radially to locate the poor of the maximal value of tyre free radius and minimum value in central authorities, that is central diameter run-out waveform maximum of points and minimum point is poor;

Setting central radial missing is CRRO, then CRRO=CR _Max-CR _Min, wherein,

CR _max＝max(CR(i))(i＝1，2…n)；

CR _min＝min(CR(i))(i＝1，2…n)；

CR (i) is radially measured datas of central authorities, i=1,2 ... n;

Described bottom radial missing be radially locate the maximal value of tyre free radius and minimum value in the bottom poor, that is bottom diameter run-out waveform maximum of points and minimum point is poor;

Setting the bottom radial missing is BRRO, then BRRO=BR _Max-BR _Min, then,

BR _max＝max(BR(i))(i＝1，2…n)；

BR _min＝min(BR(i))(i＝1，2…n)；

BR (i) is a radially measured data of bottom, i=1,2 ... n;

Described bottom lateral deviation is poor in sidewall, bottom tire lateral attitude maximal value and minimum value, that is sidewall, bottom the poor of waveform maximum of points and minimum point that beat;

Setting the bottom lateral deviation is BLRO, then, and BLRO=BL _Max-BL _MinWherein,

BL _max＝max(BL(i))(i＝1，2…n)；

BL _min＝min(BL(i))(i＝1，2…n)；

BL (i) be bottom side to measured data, i=1,2 ... n;

The bulge of described top is poor in sidewall, top lateral attitude maximal value and average;

Described top depression is poor in sidewall, top lateral attitude average and minimum value;

Setting the top bulge is TB, and top depression is TD, then TB=TL _Hmax-TL _Havg, TD=TL _Havg-TL _Hmin, wherein, TL _Hmax=max (TL _h(i)) (i=1,2 ... n);

TL _hmin＝mi _n(TLh(i))(i＝1，2…n)；

${\mathrm{TL}}_{\mathrm{havg}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{TL}}_h\left(i\right)}{n};$

TL _h(i) be the high pressure top side to measured data, i=1,2 ... n;

The bulge of described bottom is poor in sidewall, bottom lateral attitude maximal value and average;

Described bottom notch is poor in sidewall, bottom lateral attitude average and minimum value;

Setting the bottom bulge is BB, and bottom notch is BD, then BB=BL _Hmax-BL _Havg, BD=BL _Havg-BL _Hmin, wherein,

BL _hmax＝max(BL _h(i))(i＝1，2…n)；

BL _hmin＝min(BL _h(i))(i＝1，2…n)；

${\mathrm{BL}}_{\mathrm{havg}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{BL}}_h\left(i\right)}{n}$

BL _h(i) be the high pressure bottom side to measured data, i=1,2 ... n.

As the measuring method of tyre non-circularity as described in the above-mentioned scheme, measure with after the parameter that forms tyre non-circularity, can synthetically verify the degree of tire geometry deformation.

The measuring method of described tyre non-circularity, employing is with the kinetic measurement of testee rotation, promptly the upper fixed at rotary main shaft has detected tyre, adopt a plurality of distance measuring sensors respectively at the top side of tire to, top radially, central authorities radially, the bottom radially with bottom side to carrying out non-contact measurement.

Under rotation situation,, thereby cause the inaccurate problem of non-roundness measurement for fear of tire owing to the existence of the amount of unbalance of tire is vibrated tire.In test process, adopt lower rotating speed, as ω=60rpm.

The contactless distance measuring sensor that adopts can be a laser range sensor, laser range sensor is moved and approaches to tyre surface, does not measure but do not touch tyre surface.

Owing to bulge, be recessed in normal inflation under and show especially out, so the mode that adopts different charge pressures to measure.

Content to sum up, the advantage that the measuring method of described tyre non-circularity has be, set up comprehensively and the theory support of reflection tyre non-circularity directly perceived.By the above-mentioned parameter value that forms and influence tyre non-circularity of measuring, can directly reflect the degree of each spot size deviation of tire, constituted the important evidence of comprehensive measurement tire quality, comparatively comprehensive, accurate for the judge of tyre non-circularity.

Description of drawings

Now the present invention is described further in conjunction with the accompanying drawings:

Fig. 1 is the instrumentation plan of described tyre non-circularity;

Embodiment

Embodiment 1, as shown in Figure 1, and the measuring method of tyre non-circularity of the present invention, be primarily aimed at following generation and influence the factor of tyre non-circularity, be i.e. beating of tire sidewall, the bulge of tire sidewall, the depression of tire sidewall, the beating of tire tire shoulder, the beating of tire tread.

For the formative factor of above-mentioned formation tyre non-circularity, need to measure following five positions of tire at least, promptly the tire top side to, top radially, central authorities radially, the tire bottom radially with the tire bottom side to.

Thus, the measuring method of tyre non-circularity of the present invention, test and calibrate the dimensional discrepancy value of tyre non-circularity successively, include top lateral deviation, top radial missing, central radial missing, bottom radial missing, bottom lateral deviation, top bulge, top depression, bottom bulge and bottom notch value.

As shown in Figure 1, be this characteristic of the rotatable body of circular ring type at tire with tubular section, the measuring method of described tyre non-circularity adopts the dynamic measurement method with the testee rotation.Wherein,

S1, S2, S3 are laser range sensor, and Z is a power spindle, and T is a detected tyre.

Under rotation situation,, thereby cause the inaccurate problem of non-roundness measurement for fear of tire owing to the existence of the amount of unbalance of tire is vibrated tire.(ω=60rpm) and the metering system of contactless (be that laser sensor moves and approach to tyre surface, but do not touch tyre surface) can ignored to the influence of tire than amount of unbalance under the slow-speed of revolution to adopt lower rotating speed in test process.

Owing to bulge, be recessed in normal inflation under and show especially out, so the mode that adopts different charge pressures to measure.

The measuring method of described tyre non-circularity has following performing step:

The first step, measure top side to, central authorities radially, bottom side is to deviation data;

Tire flatly is installed on the main shaft, and fill with specified measuring air pressure to tire, and it is constant to keep-up pressure, main shaft rotates with the speed of 60rpm, laser sensor S1 moves and approaches to the top lateral position, and make the tire top side in the position is in the measurement range of laser sensor S1, laser sensor S2 moves and approaches to central radial position, and central radial position is in the measurement range of laser sensor S2, laser sensor S3 moves and approaches to tire bottom lateral position, and makes bottom side in the position is in the measurement range of laser sensor S3;

When three laser sensors all put in place, begin to carry out data acquisition; In gatherer process, three laser sensors all remain static; In a rotation period, gather the data that three each n of laser sensor are ordered equably, the end data collection, then record data are:

Top side is to data: TL (i) (i=1,2 ... n);

Central authorities radial data: CR (i) (i=1,2 ... n);

Bottom side is to data: BL (i) (i=1,2 ... n);

In second step, measure top radial missing data;

Laser sensor S2 moves to the top radial position, and makes top side in the position is in the measurement range of laser sensor S2, after sensor is in place, remains static, and begins to carry out data acquisition; In a rotation period, gather the data of n the point of laser sensor S2 equably, the end data collection, record data are:

Top radial data: TR (i) (i=1,2 ... n);

In the 3rd step, measure bottom radial missing data;

Laser sensor S2 moves to the bottom radial position, and makes bottom side in the position is in the measurement range of laser sensor S2, after sensor is in place, remains static, and begins to carry out data acquisition;

In a rotation period, gather laser sensor S2n point data equably, the end data collection, record data are:

Bottom radial data: BR (i) (i=1,2 ... n);

In the 4th step, measure bulge, depression data;

Bulge and be recessed under the tire normal inflation and be not easy to display, in order accurately to measure the bulge and the depression of tire, this step will increase inflation pressure of tire (charge pressure is higher than the inflation pressure of tire in first three step, and concrete pressure is actual definite according to producing), and it is constant to keep-up pressure;

Mobile laser sensor S1 is to the top lateral position, and make top side in the position is in the measurement range of laser sensor S1, mobile laser sensor S3 is to the bottom lateral position, and make bottom side in the position is in the measurement range of laser sensor S3, after two sensors are in place, keep stationary state, begin to carry out data acquisition;

In a rotation period, gather the data that each n of laser sensor S1, S3 is ordered equably, the end data collection, record data are:

The high pressure top side is to data: TL _h(i) (i=1,2 ... n);

The high pressure bottom side is to data: BL _h(i) (i=1,2 ... n);

After collection finished, laser sensor was return, and main shaft stops the rotation, and bled a tire;

The 5th goes on foot, and determines the out-of-roundness parameter of tire;

In the derivation below, use max () function and min () function, wherein max () function is to select a maximal value in parameter; Min () function is for finding a minimum value in parameter;

1. calculate top lateral deviation TLRO;

Calculate TL (i) (i=1,2 ... n) maximal value in and minimum value, then,

TL _max＝max(TL(i))(i＝1，2…n)；

TL _min＝min(TL(i))(i＝1，2…n)；

Then, TLRO=TL _Max-TL _Min

2. calculate top side to 1～10 subharmonic;

According to the Fourier transform formula, to TL (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

3. calculate top radial missing TRRO;

Calculate TR (i) (i=1,2 ... n) maximal value in and minimum value, then,

TR _max＝max(TR(i))(i＝1，2…n)

TR _min＝min(TR(i))(i＝1，2…n)

Then, TRRO=TR _Max-TR _Min

4. calculate radially 1～10 subharmonic of top;

According to the Fourier transform formula, to TR (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

5. calculate central radial missing CRRO;

Calculate CR (i) (i=1,2 ... n) maximal value in and minimum value, then,

CR _max＝max(CR(i))(i＝1，2…n)；

CR _min＝min(CR(i))(i＝1，2…n)；

Then, CRRO=CR _Max-CR _Min

6. calculate radially 1～10 subharmonic of central authorities;

According to the Fourier transform formula, to CR (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

7. calculate bottom radial missing BRRO;

Calculate BR (i) (i=1,2 ... n) maximal value in and minimum value, then,

BR _max＝max(BR(i))(i＝1，2…n)；

BR _min＝min(BR(i))(i＝1，2…n)；

Then, BRRO=BR _Max-BR _Min

8. calculate radially 1～10 subharmonic of bottom;

According to the Fourier transform formula, to BR (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

9. calculate bottom lateral deviation BLRO;

Calculate BL (i) (i=1,2 ... n) maximal value in and minimum value, then

BL _max＝max(BL(i))(i＝1，2…n)；

BL _min＝min(BL(i))(i＝1，2…n)；

Then, BLRO=BL _Max-BL _Min

10. calculate bottom side to 1～10 subharmonic;

According to the Fourier transform formula, to BL (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

11. calculate top bulge TB and top depression TD;

Calculate TL _h(i) (i=1,2 ... n) maximal value in, minimum value and mean value, then,

TL _hmax＝max(TL _h(i))(i＝1，2…n)；

TL _hmin＝min(TL _h(i))(i＝1，…n)；

${\mathrm{TL}}_{\mathrm{havg}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{TL}}_h\left(i\right)}{n};$

Then, TB=TL _Hmax-TL _Havg, TD=TL _Havg-TL _Hmin

12. calculate bottom bulge BB and bottom notch BD;

Calculate BL _h(i) (i=1,2 ... n) maximal value in, minimum value and mean value, then,

BL _hmax＝max(BL _h(i))(i＝1，2…n)；

BL _hmin＝min(BL _h(i))(i＝1，2…n)；

${\mathrm{BL}}_{\mathrm{havg}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{BL}}_h\left(i\right)}{n}$

Then, BB=BL _Hmax-BL _Havg

BD＝BL _havg-BL _hmin

Above-mentioned formation also influences the size of these parameter values of tyre non-circularity, has directly reflected the degree of each spot size deviation of tire, is the important evidence of comprehensively weighing tire quality.Having lacked any one parameter, all is not comprehensive, inaccurate for the judge of tyre non-circularity.

Claims (4)

1, a kind of measuring method of tyre non-circularity, it is characterized in that: adopt kinetic measurement the testee rotation, promptly the upper fixed at rotary main shaft has detected tyre, adopt a plurality of distance measuring sensors respectively at the top side of tire to, top radially, central authorities radially, the bottom radially with bottom side to carrying out non-contact measurement;

In test process, adopt lower rotating speed, avoid tire under rotation situation, owing to the existence of the amount of unbalance of tire is vibrated tire;

For the included parameter of tyre non-circularity, test and calibrate the dimensional discrepancy value of tire successively, include top lateral deviation, top radial missing, central radial missing, bottom radial missing, bottom lateral deviation, top bulge, top depression, bottom bulge and bottom notch value;

Described top lateral deviation is poor in the maximal value of the lateral attitude size of sidewall, top tire and minimum value, that is sidewall, top the poor of the maximum of points of waveform and minimum point that beat;

Setting the top lateral deviation is TLRO, then TLRO=TL _Max-TL _Min, wherein,

TL _max＝max(TL(i)) (i＝1，2…n)；

TL _min＝min(TL(i)) (i＝1，2…n)；

TL (i) be top side to measured data, i=1,2 ... n;

Described top radial missing be radially locate the maximal value of tyre free radius and minimum value at the top poor, that is top diameter run-out waveform maximum of points and minimum point is poor;

Setting the top radial missing is TRRO, then TRRO=TR _Max-TR _Min, wherein,

TR _max＝max(TR(i)) (i＝1，2…n)；

TR _min＝min(TR(i)) (i＝1，2…n)；

TR (i) is a radially measured data of top, i=1,2 ... n;

Described central radial missing be radially to locate the poor of the maximal value of tyre free radius and minimum value in central authorities, that is central diameter run-out waveform maximum of points and minimum point is poor;

Setting central radial missing is CRRO, then CRRO=CR _Max-CR _Min, wherein,

CR _max＝max(CR(i)) (i＝1，2…n)；

CR _min＝min(CR(i)) (i＝1，2…n)；

CR (i) is radially measured datas of central authorities, i=1,2 ... n;

Described bottom radial missing be radially locate the maximal value of tyre free radius and minimum value in the bottom poor, that is bottom diameter run-out waveform maximum of points and minimum point is poor;

Setting the bottom radial missing is BRRO, then BRRO=BR _Max-BR _Min, then,

BR _max＝max(BR(i)) (i＝1，2…n)；

BR _min＝min(BR(i)) (i＝1，2…n)；

BR (i) is a radially measured data of bottom, i=1,2 ... n;

Described bottom lateral deviation is poor in sidewall, bottom tire lateral attitude maximal value and minimum value, that is sidewall, bottom the poor of waveform maximum of points and minimum point that beat;

Setting the bottom lateral deviation is BLRO, then, and BLRO=BL _Max-BL _MinWherein,

BL _max＝max(BL(i)) (i＝1，2…n)；

BL _min＝min(BL(i)) (i＝1，2…n)；

BL (i) be bottom side to measured data, i=1,2 ... n;

The bulge of described top is poor in sidewall, top lateral attitude maximal value and average;

Described top depression is poor in sidewall, top lateral attitude average and minimum value;

Setting the top bulge is TB, and top depression is TD, then TB=TL _Hmax-TL _Havg, TD=TL _Havg-TL _Hmin, wherein, TL _Hmax=max (TL _h(i)) (i=1,2 ... n);

TL _hmin＝min(TL _h(i)) (i＝1，2…n)；

${\mathrm{TL}}_{\mathrm{havg}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{TL}}_h\left(i\right)}{n};$

TL _h(i) be the high pressure top side to measured data, i=1,2 ... n;

The bulge of described bottom is poor in sidewall, bottom lateral attitude maximal value and average;

Described bottom notch is poor in sidewall, bottom lateral attitude average and minimum value;

Setting the bottom bulge is BB, and bottom notch is BD, then BB=BL _Hmax-BL _Havg, BD=BL _Havg-BL _Hmin, wherein,

BL _hmax＝max(BL _h(i)) (i＝1，2…n)；

BL _hmin＝min(BL _h(i)) (i＝1，2…n)；

${\mathrm{BL}}_{\mathrm{havg}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{BL}}_h\left(i\right)}{n}$

BL _h(i) be the high pressure bottom side to measured data, i=1,2 ... n.

2, the measuring method of tyre non-circularity according to claim 1 is characterized in that: the contactless distance measuring sensor of employing is a laser range sensor, laser range sensor is moved and approaches to tyre surface, does not measure but do not touch tyre surface.

3, the measuring method of tyre non-circularity according to claim 2 is characterized in that: different parameters adopts different charge pressures to measure with the different size tire.

4, the measuring method of tyre non-circularity according to claim 3 is characterized in that: implementation step is,

The first step, measure top side to, central authorities radially, bottom side is to deviation data;

Tire flatly is installed on the main shaft, fill with specified measuring air pressure and keep-up pressure constant to tire, main shaft rotates with a constant speed, laser range sensor S1, S2, S3 move respectively and approach to top side to, central authorities radially with bottom side to the measuring position, and laser range sensor is in the measurement range;

When three laser range sensors all put in place, begin to carry out data acquisition; In gatherer process, three laser range sensors all remain static; In a rotation period, gather the data that three each n of laser range sensor are ordered equably, the end data collection;

In second step, measure top radial missing data;

Laser range sensor S2 moves to the top radial position, and the top radial position is in the measurement range of laser range sensor S2, after laser range sensor S2 is in place, remains static, and begins to carry out data acquisition; In a rotation period, gather the data of n the point of laser range sensor S2 equably, the end data collection;

In the 3rd step, measure bottom radial missing data;

Laser range sensor S2 moves to the bottom radial position, and the bottom radial position is in the measurement range of laser range sensor S2, after sensor is in place, remain static, the tire low speed rotation, avoiding tire under rotation situation,, begin to carry out data acquisition owing to the existence of the amount of unbalance of tire is vibrated tire;

In a rotation period, laser range sensor S2 gathers the n point data equably, the end data collection;

In the 4th step, measure bulge, depression data;

Increase inflation pressure of tire to the inflation pressure of tire that is higher than first three step, and it is constant to keep-up pressure;

Mobile laser range sensor S1 is to the top lateral position, and make top side in the position is in the measurement range of laser range sensor S1, move another laser range sensor S3 to the bottom lateral position, and make bottom side in the position is in the measurement range of laser range sensor S3, after two sensors are in place, keep stationary state, the tire low speed rotation, avoiding tire under rotation situation,, begin to carry out data acquisition owing to the existence of the amount of unbalance of tire is vibrated tire;

In a rotation period, gather the data that each n of 2 laser range sensors is ordered equably, the end data collection; After collection finished, laser range sensor was return, and main shaft stops the rotation, and bled a tire;

The 5th goes on foot, and determines the out-of-roundness parameter of tire;

Calculate top lateral deviation TLRO;

Calculate top side to 1～10 subharmonic, according to the Fourier transform formula, to TL (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

Calculate top radial missing TRRO;

Calculate radially 1～10 subharmonic of top, according to the Fourier transform formula, to TR (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

Calculate central radial missing CRRO;

Calculate radially 1～10 subharmonic of central authorities, according to the Fourier transform formula, to CR (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

Calculate bottom radial missing BRRO;

Calculate radially 1～10 subharmonic of bottom, according to the Fourier transform formula, to BR (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

Calculate bottom lateral deviation BLRO;

Calculate bottom side to 1～10 subharmonic, according to the Fourier transform formula, to BL (i) (i=1,2 ... n) calculate, can obtain amplitude, the phase information of 1～10 subharmonic;

Calculate top bulge TB and top depression TD;

Calculate bottom bulge BB and bottom notch BD.