CN1259543C - Laser vision on-line automatic measuring method for tire multiple geometrical parameters - Google Patents

Laser vision on-line automatic measuring method for tire multiple geometrical parameters Download PDF

Info

Publication number
CN1259543C
CN1259543C CN 03142656 CN03142656A CN1259543C CN 1259543 C CN1259543 C CN 1259543C CN 03142656 CN03142656 CN 03142656 CN 03142656 A CN03142656 A CN 03142656A CN 1259543 C CN1259543 C CN 1259543C
Authority
CN
China
Prior art keywords
tire
target
square
plane
measuring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN 03142656
Other languages
Chinese (zh)
Other versions
CN1566903A (en
Inventor
周富强
张广军
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beihang University
Beijing University of Aeronautics and Astronautics
Original Assignee
Beihang University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beihang University filed Critical Beihang University
Priority to CN 03142656 priority Critical patent/CN1259543C/en
Publication of CN1566903A publication Critical patent/CN1566903A/en
Application granted granted Critical
Publication of CN1259543C publication Critical patent/CN1259543C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Length Measuring Devices By Optical Means (AREA)

Abstract

The present invention belongs to the measuring technical field and provides an on-line automatic non-contact measuring method for a plurality of geometric parameters of a tyre. The present invention projects a laser light plane to a tyre, and utilizes a CCD video camera to acquire the image of a deformation characteristic line. According to the three-dimensional information of key characteristic points of the profile of the surface of the tyre, a plurality of geometric size parameters of the tyre are calculated. The present invention realizes the measurement of a plurality of geometric parameters of a tyre once by a single sensor. A measurement sensor has the advantages of simple structure, low cost, higher measuring accuracy, high measuring efficiency, wide measuring range, high automation degree of the measuring device and simple measuring process, and can measure tyres with different specifications.

Description

The on-line automatic measuring method of the laser vision of the many geometric parameters of tire
Technical field
The invention belongs to field of measuring technique, will provide the on-line automatic non-contact measurement method of the many geometric parameters of a kind of tire.
Background technology
The dynamic balance of tire is an important parameter of examination tire quality.When tire dynamic and balance out of order the time, then excessive or too small to the centrifugal force of certain direction, thus influence tire quality, very easily cause in service blowing out after being installed on the automobile when serious, cause security incident.The tire industry of China is in the period of model change, and the exploitation of high performance tire is at the early-stage, presses for the factory inspection of strengthening product, the amount of unbalance of control tire.Need expand checked object to other specification from supporting specification, expand all over products to from auxiliary products.Gold dynamic balancing measurement machine automatically promptly is the special-purpose key equipment that solves this demand.Will carry out 100% on-line automatic dynamic balance running to different types of tyre, must tell the model of tire automatically, be one of a kind of effective means according to tire physical dimension identification tire specification.In addition, in the processing and manufacturing process of tire, when tire tread is extruded, be subjected to mix quality, extrude controlled variable, the influence of the factors such as fluctuation of status of equipment, can cause the size distortion of tread width, thickness.If can in time measure deflections such as tread width and thickness, in time adjust process equipment, just can avoid waste product or half-finished appearance.Therefore, the measurement of tire physical dimension is significant, and it can be used for the tire dynamic and balance test and discern tire specification, and carries out quality monitoring and quality assurance in the tire process.
Existing tire geometric parameter measurement mainly contains manual measurement and photoelectric measurement dual mode.Manual measurement efficient is low, and labour intensity is big, and poor accuracy can not satisfy the needs of 100% online detection.In the photoelectric measurement mode, a kind of mode be with typical laser displacement sensor according to different measurement requirement appropriate combination, be used for industries such as rubber high-precision noncontact thickness measuring, survey wide, survey long etc.Laser thickness, width measuring instrument as Chinese Academy of Sciences's Anhui optical precision optical machinery research development.Another kind of mode is to measure the testee size according to blocking principle, as the high response of the optoCONTROL2500-35 laser milscale of Germany rice iridium measuring technology company development, can be used for measuring the geometric parameter of tire.In existing photoelectric measurement method, every suit equipment can only be measured a parameter of tire, can not measure simultaneously a plurality of geometric parameters of tire, therefore will measure the many geometric parameters of tire, needs many complete equipments, the equipment cost height, and measurement range is limited.
Summary of the invention
Technical matters to be solved by this invention is: provide a kind of precision higher, measurement range is big, and efficiency of measurement height, single-sensor can be measured the on-line automatic measuring method of many geometric parameters such as the inside and outside diameter of tire and section width simultaneously.To reduce the volume of measuring equipment, reduce the cost of measuring equipment, improve the convenience that its through engineering approaches is used.
Technical solution of the present invention is: a kind of on-line automatic measuring method of tire geometric parameter, it is characterized in that measuring process is divided demarcation and measured two stages, but continuous coverage after once demarcating, concrete steps are as follows:
1 calibration phase:
1.1, place tire model measuring station, it is the circular entity of processing and manufacturing, lower surface is a plane, it is the circular hole of 5～50mm that there is a diameter at the center, use fixed automatically in mechanism with tire model fixed in;
1.2, in measure field laser vision sensor is installed, open probe power, adjust the position of sensor, the optical plane that makes sensor projects go out is vertical with reference plane, and passes through the center of model tire, and vision sensor is fixed;
1.3, take the image of tire model, automatically extract the image coordinate at tire center, and the striation that projects the tire model upper surface, use image processing algorithm, striation center extraction algorithm extracts the striation center, and fitting a straight line, as reference line, remove tire model from measuring station then;
1.4, set target, target is a two dimensional surface, and the unique point that sets in advance is arranged on the target surface, the target face is one of following structure:
A, target first, on the target plane, be covered with chequered with black and white gridiron pattern, the length of side of black and white square is (3～50) mm, its length of side precision is (0.001～0.01) mm, the publicly-owned summit of black box and white square is called lattice point, choose that lattice point is as feature point for calibration on the target surface, the quantity of unique point is 16～400;
B, target second, the black square that arranged is arranged on the target plane, square quantity is 4～100, the length of side of square is (3～50) mm, its length of side precision is (0.001～0.01) mm, the square spacing is 3～50mm, and its spacing precision is (0.001～0.01) mm, and the summit of choosing each square is a unique point;
1.5, in the field range of video camera, a position is whenever moved in free, at least 5 positions of plane of motion target, non-parallel ground, takes piece image, requires the black square of plane target drone to be included in the image;
1.6, extract the image coordinate of all feature point for calibration, and itself and corresponding world coordinate are used for the calibrating camera inner parameter;
1.7, place 3 D stereo and demarcate target, this is demarcated target and is made up of two orthogonal planes, the protruding black square of two row, two row is arranged on each plane, square quantity is 2～50 in every row, the square spacing is 10～100mm, precision is (0.01～0.1) mm, and each square summit is a unique point;
1.8, take the width of cloth three-dimensional target picture of marking on a map, require the striation can be, and image comprises all black squares of target laterally by on delegation's black square of target;
1.9, extract the summit image coordinate of striation and all black squares, calculating feature point for calibration is the image coordinate of the intersection point of striation fitting a straight line and same row black square summit fitting a straight line, utilizes the double ratio invariance principle, the world coordinates of calculating feature point for calibration;
1.10, utilize feature point for calibration image coordinate and the world coordinates obtain, the structural parameters of Calibration of Laser vision sensor;
1.11, intrinsic parameters of the camera, sensor construction parameter, the tire centre of location and the reference line parameter of demarcating is saved in the systems parameters document, call in order to measuring phases;
2, measuring phases:
2.1, by the tire connecting gear detected tyre is transported to the measurement station automatically, during tire is fixed mechanism with detected tyre fixed automatically in;
2.2, take the image of tire;
2.3, extract the central feature line project striation on the surface of tyre, extract the projection master characteristic curve of tire and the image coordinate of key feature point automatically, according to camera model, be converted into the normalized image coordinate;
2.4, according to the sensor measurement model, the physical dimension that calculates tire is inside and outside diameter of tire and section width, shows measurement result.
2.5, repeat 2.1～2.4, carry out new tire and measure.
Advantage of the present invention is: the first, realized the many geometric parameters of single-sensor one-shot measurement tire, avoided adopting many complete equipments to measure many geometric parameters of tire; The second, survey sensor is simple in structure, cost is low, measuring accuracy is higher, efficiency of measurement is high, measurement range is big, can measure different types of tyre; Three, measuring equipment automaticity height, measuring process is simple.
Description of drawings
Fig. 1 is many geometric parameters of tire laser vision measuring principle synoptic diagram.Among Fig. 1, the 1st, detected tyre, the 2nd, tire outside diameter unique point, the 3rd, tire diameter unique point, the 4th, projection properties line, the 5th, laser vision sensor, the 6th, reference line, the 7th, the tire centre of location, the 8th, projection light plane.
Fig. 2 is the laser vision sensor mathematical model.Among Fig. 2, the 9th, optical plane, the 10th, laser projecting apparatus, the 11st, the plane of delineation.
Fig. 3 is a laser vision sensor calibration principle synoptic diagram.
Fig. 4 demarcates the tire centre of location and reference line synoptic diagram.Among Fig. 4, the 12nd, reference line, the 13rd, the tire centre of location, the 14th, tire model.
Fig. 5 is a plane reference target synoptic diagram.
Fig. 6 is that 3 D stereo is demarcated the target synoptic diagram.Among Fig. 6, the 15th, demarcate target, the 16th, the projecting laser striation.
Fig. 7 is that multistep processes is extracted tire measurement features signal principle figure.Among Fig. 7, the 17th, tire outside diameter unique point, the 18th, tire diameter unique point, the 19th, projection master characteristic curve, the 20th, the tire centre of location.
Fig. 8 is mounted in on-the-spot laser vision sensor pictorial diagram.Among Fig. 8, the 21st, sensor power supply line, output signal Interface Terminal, the 22nd, ccd video camera form, the 23rd, sensor attachment mechanism, the 24th, sensor housing, the 25th, laser projecting apparatus window.
Fig. 9 is the tire image of obtaining under the measurement state.
Embodiment
Below the inventive method is described in further details.The present invention combines modern laser and computer vision technique, on-line automatic measurement when using single-sensor to realize the many geometric parameter of tire first.Its ultimate principle is the optical triangulation method.As shown in Figure 1, laser projecting apparatus projects an optical plane 8, optical plane is intercepted deformation behaviour line 4 by tire 1 surface, utilize ccd video camera to obtain the image of these deformation behaviour lines, the characteristic curve image coordinate of treated obtaining " sub-pix " precision, if the model parameter of known laser vision sensor just can be obtained the three-dimensional information of surface of tyre profile by the optical triangulation method, according to the three-dimensional information of the key feature point of surface of tyre profile, just can calculate a plurality of physical dimension parameters of tire.At first guarantee that by the fixed middle mechanism of tire tire is positioned at the dead center position 7 on the reference plane, adjusting gear and sensor adjusting mechanism by laser vision sensor inside, the optical plane 8 that adjustment projects, make optical plane also pass through the centre of location 7 of tire perpendicular to the tire positioning reference plane, therefore for different types of tyre, optical plane can both be by the diametric(al) of tire, and be deflected width of tyre to the vertical range of positioning reference plane by crown (being the tire peak), therefore in the sensor measurement coordinate system, obtain reference line and crown coordinate, just can directly calculate deflected width of tyre by the tire centre of location.Obtain the image coordinate of surface of tyre key feature point 2 and put 3 image coordinate, in sensor coordinate system, two unique points are projected on the reference line, and obtain subpoint after the distance of the tire centre of location, just can calculate the inner and outer diameter of tire.
The mathematical model of laser vision sensor.
The mathematical model of the laser vision sensor of being made up of ccd video camera and laser projecting apparatus as shown in Figure 2.The video camera three-dimensional coordinate is o cx cy cz c, it is OXY that image is sat plane 11 coordinates.On optical plane 9 with 1 o sBe initial point, set up the measurement coordinate system o of sensor sx sy sz s, optical plane o wherein sx sy sEquation under the witness mark coordinate system is:
z s＝0 (1)
If the homogeneous coordinates of any 1 P under the sensor measurement coordinate system are on the optical plane
p ~ s = ( x s , y s , z s , 1 ) T , Perspective projection point on the plane of delineation is p, and the homogeneous coordinates of p are
p ~ l = ( x l , y l , 1 ) T , Corresponding normalization coordinate is p ~ n = ( x n , y n , 1 ) T .
The perspective projection model of video camera can be shown:
ρ p ~ l = [ R | T ] p ~ s , ρ ≠ 0 - - - ( 2 )
λ p ~ n = A - 1 p ~ l , λ ≠ 0 - - - ( 3 )
Wherein A = f x 0 u 0 0 f y v 0 0 0 1 R = r 1 r 2 r 3 r 4 r 5 r 6 r 7 r 8 r 9 , T = t x t y t z . A is the intrinsic parameters of the camera matrix, (f x, f y) be the effective focal length of video camera on x, y direction, (u 0, v 0) be the principal point coordinate of video camera.R is 3 * 3 unit quadrature rotation matrixs, and T is a translation vector.R and T have represented the mutual alignment relation between video camera three-dimensional system of coordinate and the sensor measurement coordinate system.
Can be got by formula (1)～(3), the transformation relation between plane of delineation coordinate system and the witness mark coordinate system is:
λ x n y n 1 = r 1 r 2 r x r 4 r 5 r y r 7 r 8 r z x s y s 1 = H x s y s 1 - - - ( 4 )
Following formula shows that the relation between the optical plane and the plane of delineation can pass through one 3 * 3 matrix representation.If preceding two row of H satisfy orthogonality condition, then formula (3) and (4) have constituted the complete mathematical model of the laser vision sensor on the theorem in Euclid space.If the inner parameter of known video camera is obtained the normalized image coordinate by (3) formula, just can obtain the space measurement coordinate of putting on the optical plane according to formula (4).
According to the mathematical model and the measuring principle of the present invention of laser vision sensor, the non-cpntact measurement of tire size is divided into two stages: the demarcation of measuring system parameter and measure two stages according to model.
The demarcation concrete steps of measuring system parameter are as follows:
The model parameter of laser vision sensor comprises inner parameter (focal length, principal point etc.) and the structural parameters (being position and the direction of camera coordinate system with respect to the LASER Light Source coordinate system) of laser vision sensor, totally 13 parameters of video camera.Except the model parameter of laser vision sensor, parameters such as tire centre of location coordinate and reference line also need to demarcate.
1, measuring station setting tire model, tire model is cylindrical aluminum entity, and as shown in Figure 4, two end faces are a plane up and down, and thickness is 50～100mm, diameter 400～800mm, and it is the circular hole of 5～50mm that a diameter is arranged at the center.During mechanism decided tire model 14 during use was fixed automatically, at this moment, the upper surface of tire model was a reference plane, and the center of tire model circular hole is the tire centre of location 13, uses (c x, c y) expression.The central line that projects to the striation of tire upper surface is a reference line 12, and its parametric equation is expressed as: ax+by+cw=0, wherein (x, y are the homogeneous coordinates representation that constitutes the unique point of straight line w), and (a, b c) are the parametric equation of reference line.
2, in measure field laser vision sensor is installed, is opened probe power, adjust the position of sensor, the optical plane that makes sensor projects go out is vertical with reference plane, and by the tire centre of location.Vision sensor is fixed;
3, gather the image of a width of cloth tire model, adopt related algorithm to extract the image (c of the tire centre of location automatically x, c y) coordinate and extraction project the striation center match reference line of tire model upper surface, and with the image (c of the tire centre of location x, c y) (a, b c) store in the computing machine for coordinate and straight line parameter.Automatic " sub-pix " extraction algorithm of the centre of location is referring to Zhou Fuqiang work " the gordian technique research that binocular stereo vision detects ", BJ University of Aeronautics ﹠ Astronautics's post-doctoral research work report, 2002.Striation center extraction algorithm is referring to the article " a kind of symmetrical curve structure detector " [An Unbiased Detector of Curvilinear Structures] of Carsten Steger, IEEE periodical " pattern analysis and machine intelligence ", 20 (2), the 113rd～125 page, 1998 years.[IEEETransactions on Pattern Analysis and Machine Intelligence，20(2)，February 1998]。
4, set target, target is a two dimensional surface, and the unique point that sets in advance is arranged on the target surface, and the target face is one of following structure:
A, target first are covered with chequered with black and white gridiron pattern on the target plane, the length of side of black and white square is (3～50) mm, and its length of side precision is (0.001～0.01) mm, and the publicly-owned summit of black box and white square is called lattice point.Choose that lattice point is as feature point for calibration on the target surface, the quantity of unique point is 16～400.
B, target second, the black square that arranged is arranged on the target plane, square quantity is 4～100, the length of side of square is (3～50) mm, its length of side precision is (0.001～0.01) mm, the square spacing is 3～50mm, and its spacing precision is (0.001～0.01) mm, and the summit of choosing each square is a unique point.
5, in the field range of video camera, a position is whenever moved in free, at least 5 positions of plane of motion target, non-parallel ground, takes piece image, requires the black square of plane target drone to be included in the image.
6, extract " sub-pix " image coordinate of the unique point of all calibrating cameras automatically, and utilize the image coordinate of feature point for calibration and corresponding world coordinate to come the calibrating camera inner parameter.Unique point coordinate extraction algorithm and calibration algorithm are referring to Zhou Fuqiang work " the gordian technique research that binocular stereo vision detects ", BJ University of Aeronautics ﹠ Astronautics's post-doctoral research work report, 2002.
7, place 3 D stereo and demarcate target, this demarcation target is made up of two orthogonal planes, and the protruding black square of two row, two row is arranged on each plane, square quantity is 2～50 in every row, the square spacing is 10～100mm, and precision is (0.01～0.1) mm, and each square summit is a unique point.
8, take mark on a map picture and storing in the computing machine of a width of cloth three-dimensional target.Require striation laterally to pass through on delegation's black square of target, and image comprise all black squares of target.
9, the summit image coordinate of striation central line 16 and all black squares on each plane of the three-dimensional demarcation of extraction target, the unique point image coordinate and the world coordinates that calculate the Calibration of Laser vision sensor also store in the computing machine.The extraction algorithm of feature striation is identical with step 3.Black square apex coordinate extraction algorithm is identical with step 6.The image coordinate of unique point is the intersection point of striation fitting a straight line and same row black square summit fitting a straight line.As shown in Figure 3, three-dimensional system of coordinate o cx cy cz cBe camera coordinate system, o wx wy wz wBe world coordinate system, o sx sy sz sBe measurement coordinate system, plane π cBe the plane of delineation, plane π s(o sx sy s) be optical plane, plane π w(o wx wy w) be plane of three-dimensional target target, π sWith π wIntersect straight line L sBy the definition and the principle of invariance of double ratio, can obtain any 4 collinear point (A i, Q i, B i, C i| i=1 ... n) double ratio and its subpoint (a in the plane of delineation i, q i, b i, c i| i=1 ... n) double ratio remains unchanged, that is:
r ( A i , Q i , B i , C i ) = A i B i Q i B i : A i C i Q i C i = a i b i q i b i : a i c i q i c i - - - ( 5 )
Known A i, B i, C iThe world coordinates of (being the coplanar characteristic point on the target plane) obtains a by Flame Image Process i, q i, b i, c iImage coordinate, then just can obtain unique point Q on the optical plane according to formula (5) iWorld coordinates.Employing is obtained three-dimensional feature point for calibration image coordinate and the corresponding world coordinates of demarcating another plane of target with quadrat method.
10, utilize feature point for calibration image coordinate and the world coordinates of obtaining, the structural parameters of Calibration of Laser vision sensor.The measurement coordinate system of sensor is o sx sy sz s, z wherein sAxle is consistent with the normal vector of optical plane, x sAxle and y sAxle is positioned at optical plane, and the initial point of measurement coordinate system is defined in the center of all non-colinear feature point for calibration
Figure C0314265600111
If p ~ s = x s y s 0 1 T Be the nonhomogeneous measurement coordinate of feature point for calibration, then world coordinates being converted to sensor coordinate system:
p ~ s = H w s p ~ w - - - ( 6 )
Wherein H w s = R w s - R w s p ~ 0 T 1 The expression world coordinates is tied to 4 * 4 transition matrixes of measurement coordinate system, and it is by 3 * 1 translation vector
Figure C0314265600115
With 3 * 3 quadrature rotation matrix R w sForm.
If the unit normal vector by the optical plane of the non-colinear unique point match more than 4 is n=(n 1n 2n 3) T, the Z-direction vector of world coordinates is z w=(0 0 1) T, then with vector n and z wThe turning axle of aiming at is a=(n * z w)/‖ n * z w‖, the anglec of rotation is =cos -1(nz w)=cos -1(n 3).So R w sCalculate by following formula:
Figure C0314265600116
Wherein I is 3 * 3 unit orthogonal matrix, I × a = 0 - a 3 a 2 a 3 0 a 1 - a 2 a 1 0 Antisymmetric matrix for vector a definition.
The 3 D stereo that is calculated by step 9 is demarcated the world coordinates of non-colinear feature point for calibration on the target optical plane, by formula (6) it is transformed under the measurement coordinate system, just can obtain the coordinate of feature point for calibration under measurement coordinate system Can obtain the normalized image coordinate of feature point for calibration by formula (3)
Figure C0314265600119
By the mathematical model (formula (4)) of laser vision sensor, the method for employing nonlinear optimization is obtained the structural parameters of sensor.Nonlinear optimization algorithm adopts the Levenberg-Marquardt algorithm, referring to " Optimum Theory and method ", (Yuan Yaxiang, Sun Wenyu work, Science Press, 1999).
11, intrinsic parameters of the camera, laser vision sensor structural parameters, the tire centre of location and the reference line parameter of demarcating is saved in the systems parameters document, calls in order to measuring phases.
The parameter calibration of measuring system only carries out once, demarcated measuring system after, just can measure many geometric parameters of tire automatically.The measurement concrete steps of the many geometric parameters of tire are as follows:
12, by the tire connecting gear detected tyre is transported to the measurement station automatically, during mechanism decided detected tyre automatically during tire was fixed.
13, gather the image of tire.
14, extract the central feature line that projects striation on the surface of tyre.Automatically extract the projection master characteristic curve of tire and the image coordinate of key feature point,, be converted into the normalized image coordinate according to formula (3).Striation center extraction algorithm is identical with step 3.As shown in Figure 9, measure the influence of station complex background and surround lighting owing to be subjected to tire, exist many and projection properties line and key feature to put similar undesired signal in the actual tire image of obtaining, the striation center of being extracted by step 18 has comprised other undesired signals.Realize all automatic measurement of tire size, must can remove these undesired signals.In addition, when the projection striation just in time falls into the decorative pattern of surface of tyre, can cause the discontinuous of projection properties curve.In the measuring system calibration phase, can obtain the image coordinate of the tire centre of location and measure coordinate, when different types of tyre was measured, the centre of location remained constant, and the actual measurement characteristic signal is positioned at the zone, upper left side of the tire centre of location in obtaining image.Therefore utilize the stationary positioned center of tire, the employing step-by-step extracting method obtains the crucial measuring-signal of tire reliably, as shown in Figure 7.Main algorithm is as follows:
* in area L ROI1In, employing striation extraction algorithm proposes to comprise the center line of projection striation, and it is linked to be curvilinear structures respectively.By setting curve length threshold (generally greater than 50) and angle threshold (± 30 °), in the curvilinear structures of all extractions, identify projection master characteristic curve 19.
* with the rightmost point P of projection master characteristic curve 19 N-1Be new processing region R of summit definition ROI, in region R ROIIn adopt the striation extraction algorithm to extract this regional light stripe centric line, and be interior diameter key feature point 18-P with the rightest point of new light stripe centric line InIf do not find new light stripe centric line in this zone, then the rightest point with projection master characteristic curve is interior diameter key feature point 18-P In
* calculate the peak (ordinate minimum) of projection master characteristic curve 19 and the intermediate value y of the ordinate of the centre of location 20 Label, and the most close y of ordinate on the supposition projection master characteristic curve 19 LabelPoint be overall diameter unique point 17-P OutIf the Far Left point P of projection master characteristic curve 19 0Along slope coordinate less than y Label, then with P 0Point is new processing region L of summit definition ROI2, in area L ROI2The interior striation extraction algorithm that adopts extracts this regional light stripe centric line, and with the most close y of ordinate on the new light stripe centric line LabelPoint be overall diameter unique point 17-P Out
15,, calculate the physical dimension (inside and outside diameter of tire and section width) of tire, display result according to the sensor measurement model.By formula (4), calculate interior diameter unique point 18-P In, overall diameter unique point 17-P OutAnd the measurement coordinate of putting on all projection master characteristic curvees 19.Calculate the space length of the reference line of having a few on the projection master characteristic curve 19, the selection maximal value is a deflected width of tyre.Under measurement coordinate system, the interior diameter unique point is projected on the reference line, and calculate the distance of subpoint to the centre of location, be the inside radius of tire.Under measurement coordinate system, the overall diameter unique point is projected on the reference line, and calculate the distance of subpoint to the centre of location, be the external radius of tire.
16, repeat 12～15, carry out new tire and measure.
Embodiment
The material object of the laser vision sensor of actual design as shown in Figure 8.Among Fig. 8, the 21st, sensor power supply line, output signal Interface Terminal, the 22nd, ccd video camera form, the 23rd, sensor attachment mechanism, the 24th, sensor housing, the 25th, laser projecting apparatus window.
According to the step of narrating above, utilize tire model shown in Figure 4, plane reference target shown in Figure 5 and 3 D stereo shown in Figure 6 to demarcate target, ccd video camera, laser vision sensor and measuring system and demarcate.The measuring system parameter that obtains is:
Intrinsic parameters of the camera: A = 952.596 0 393.391 0 949.901 309.320 0 0 1 pixel
The sensor construction parameter: H = 0.926475 - 0.311043 - 47.213 - 0.301995 - 0.278446 - 177.155 - 0.224591 - 0.908691 882.040
Tire reference line parameter is: (a, b, c)=(169.432047,278.500496,108216.664203)
The image coordinate of the tire centre of location is: (c x, c y)=(368.423,318.054) pixel
The RMS error of 2 distances in vision sensor Measuring Object space of demarcating is: E RMS=0.135mm.
Adopt this invention at the scene different size tires such as model R12, R13, R14 and R16 to be carried out 5 times and measure, Fig. 9 is one of tire image of obtaining under the measurement state.Adopt steel tape that the size of actual tire has been carried out hand dipping simultaneously, it is as shown in the table for measurement data.The in-site measurement data:
Model Tire diameter (in) Tire outside diameter (cm) Tyre section width (cm)
Laser measurement (5 times average) Tape measure Laser measurement (5 times average) Tape measure Laser measurement (5 times average) Tape measure
R12 11.93 11.88 50.73 50.8 14.78 14.6
R13 13.12 13.18 56.27 56.20 16.27 16.1
R14 13.97 13.97 64.59 64.8 19.31 19.1
R16 16.01 15.95 61.86 62.00 23.49 23.3
Deflected width of tyre, tire outside diameter, the laser vision non-cpntact measurement repeatability precision of tire diameter be less than ± 0.8mm, with the hand dipping difference less than ± 2.5mm.
Actual other measurement index that reaches of sensor is:
* on the computing machine of PIII (CPU 1G, internal memory 128Mhz) the single measurement Measuring Time less than 200ms.
* the measurement maximum tire specification of sensor is: tire diameter is 600mm to the maximum; Tire outside diameter is 1000mm to the maximum; Deflected width of tyre is 800mm to the maximum.

Claims (1)

1, a kind of on-line automatic measuring method of tire geometric parameter is characterized in that, measuring process is divided demarcation and measured two stages, but continuous coverage after once demarcating, and concrete steps are as follows:
1.1 calibration phase:
1.1.1, place tire model measuring station, it is the circular entity of processing and manufacturing, lower surface is a plane, it is the circular hole of 5～50mm that there is a diameter at the center, use fixed automatically in mechanism with tire model fixed in;
1.1.2, in measure field laser vision sensor is installed, open probe power, adjust the position of sensor, the optical plane that makes sensor projects go out is vertical with reference plane, and passes through the center of model tire, and vision sensor is fixed;
1.1.3, take the image of tire model, automatically extract the image coordinate at tire center, and the striation that projects the tire model upper surface, use image processing algorithm, striation center extraction algorithm extracts the striation center, and fitting a straight line, as reference line, remove tire model from measuring station then;
1.1.4, set target, target is a two dimensional surface, and the unique point that sets in advance is arranged on the target surface, the target face is one of following structure:
A, target first, on the target plane, be covered with chequered with black and white gridiron pattern, the length of side of black and white square is 3～50mm, its length of side precision is 0.001～0.01mm, the publicly-owned summit of black box and white square is called lattice point, choose that lattice point is as feature point for calibration on the target surface, the quantity of unique point is 16～400;
B, target second have into the black square of arranged on the target plane, square quantity is 4～100, the length of side 3～the 50mm of square, its length of side precision is 0.001～0.01mm, the square spacing is 3～50mm, its spacing precision 0.001～0.01mm, the summit of choosing each square is a unique point;
1.1.5, in the field range of video camera, a position is whenever moved in free, at least 5 positions of plane of motion target, non-parallel ground, takes piece image, requires the black square of plane target drone to be included in the image;
1.1.6, extract the image coordinate of feature point for calibration, and itself and corresponding world coordinate are used for the calibrating camera inner parameter;
1.1.7, place 3 D stereo and demarcate target, this is demarcated target and is made up of two orthogonal planes, the protruding black square of two row, two row is arranged on each plane, square quantity is 2～50 in every row, the square spacing is 10～100mm, precision is 0.01～0.1mm, and each square summit is a unique point;
1.1.8, take the width of cloth three-dimensional target picture of marking on a map, require the striation can be, and image comprises all black squares of target laterally by on delegation's black square of target;
1.1.9, extract the summit image coordinate of striation and all black squares, calculating feature point for calibration is the image coordinate of the intersection point of striation fitting a straight line and same row black square summit fitting a straight line, utilize the double ratio invariance principle, calculate the world coordinates of feature point for calibration;
1.1.10, utilize feature point for calibration image coordinate and the world coordinates obtain, the structural parameters of Calibration of Laser vision sensor;
1.1.11, intrinsic parameters of the camera, sensor construction parameter, the tire centre of location and the reference line parameter of demarcating is saved in the systems parameters document, call in order to measuring phases;
1.2, measuring phases:
1.2.1, by the tire connecting gear detected tyre is transported to the measurement station automatically, during tire is fixed mechanism with detected tyre fixed automatically in;
1.2.2, take the image of tire;
1.2.3, extract the central feature line project striation on the surface of tyre, extract the projection master characteristic curve of tire and the image coordinate of key feature point automatically, according to camera model, be converted into the normalized image coordinate;
1.2.4, according to the sensor measurement model, the physical dimension that calculates tire is inside and outside diameter of tire and section width, shows measurement result.
1.2.5, repeat 1.2.1～1.2.4, carry out new tire and measure.
CN 03142656 2003-06-11 2003-06-11 Laser vision on-line automatic measuring method for tire multiple geometrical parameters Expired - Fee Related CN1259543C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 03142656 CN1259543C (en) 2003-06-11 2003-06-11 Laser vision on-line automatic measuring method for tire multiple geometrical parameters

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 03142656 CN1259543C (en) 2003-06-11 2003-06-11 Laser vision on-line automatic measuring method for tire multiple geometrical parameters

Publications (2)

Publication Number Publication Date
CN1566903A CN1566903A (en) 2005-01-19
CN1259543C true CN1259543C (en) 2006-06-14

Family

ID=34471152

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 03142656 Expired - Fee Related CN1259543C (en) 2003-06-11 2003-06-11 Laser vision on-line automatic measuring method for tire multiple geometrical parameters

Country Status (1)

Country Link
CN (1) CN1259543C (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101738158B (en) * 2008-11-26 2011-11-23 软控股份有限公司 Method for measuring tyre size
RU2728848C2 (en) * 2016-04-05 2020-07-31 Пирелли Тайр С.П.А. Tire monitoring device and method

Families Citing this family (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4881584B2 (en) * 2005-06-28 2012-02-22 株式会社ブリヂストン How to create master data for inspection of uneven figures
CN1789907A (en) * 2005-12-27 2006-06-21 渤海船舶重工有限责任公司 Inside diameter measurement system for big-size shaft hole
FR2925687B1 (en) * 2007-12-19 2010-02-12 Soc Tech Michelin METHOD OF EVALUATION BY COMPARISON OF AN ACQUIRED IMAGE WITH A REFERENCE IMAGE.
CN101660895B (en) * 2008-08-29 2012-06-20 鸿富锦精密工业（深圳）有限公司 Computer system and method for accurately positioning element to be measured
US8650766B2 (en) * 2008-09-12 2014-02-18 Robert Bosch Gmbh Target system, set of target systems and device for optically aligning an axle
DE102008054975A1 (en) 2008-12-19 2010-07-01 Robert Bosch Gmbh Method for chassis measurement and device for measuring the chassis geometry of a vehicle
CN102022978B (en) * 2009-09-22 2012-09-05 复旦大学 Optimization method for detecting and positioning by detecting instrument
CN101832760B (en) * 2010-04-23 2011-12-07 清华大学 Remote three-dimensional micro-deformation visual on-line monitoring method and system
JP5518571B2 (en) * 2010-05-24 2014-06-11 株式会社ブリヂストン Tire appearance inspection apparatus and appearance inspection method
CN101893425B (en) * 2010-07-09 2012-06-27 清华大学 Visual full-parameter wheel alignment detection system and method based on linear array images
CN101975588B (en) * 2010-08-20 2012-07-11 北京航空航天大学 Global calibration method and device of rigid rod of multisensor vision measurement system
CN102506783A (en) * 2011-11-23 2012-06-20 人本集团有限公司 Method for measuring size of bearing sealing ring
JP5969906B2 (en) * 2012-11-29 2016-08-17 株式会社神戸製鋼所 Measuring method and measuring device
CN104251667B (en) * 2014-09-24 2017-10-27 北京航空航天大学 Away from dynamic measurement method and system on the inside of a kind of Railway wheelset
WO2016179798A1 (en) * 2015-05-12 2016-11-17 Bayerische Motoren Werke Aktiengesellschaft A system and a computer-implemented method for calibrating at least one senser
ITUB20155721A1 (en) * 2015-11-19 2017-05-19 Pirelli Method and control line of tires for vehicle wheels
CN106813569B (en) * 2015-11-30 2019-02-15 中国科学院沈阳自动化研究所 A kind of automobile tire 3-D positioning method based on line-structured light
CN105424008A (en) * 2015-12-01 2016-03-23 广东顺德华焯机械科技有限公司 Laser marking galvanometer scanning system based on machine vision
CN105458833A (en) * 2015-12-04 2016-04-06 重庆大学 Workpiece rotating center measuring device and method
CN106289105A (en) * 2016-10-31 2017-01-04 吉林大学 The verification system of automobile tire Shape measure instrument based on active vision
CN108229393A (en) * 2018-01-02 2018-06-29 湖北工业大学 A kind of the high-precision identifying system and method for automobile tire mark
CN110398214B (en) * 2019-08-01 2021-05-11 桂林梵玛科机械有限公司 Method for rapidly measuring outer contour dimension of tire body
CN113267137B (en) * 2021-05-28 2023-02-03 北京易航远智科技有限公司 Real-time measurement method and device for tire deformation
CN114638857A (en) * 2022-03-21 2022-06-17 南京工业大学 Non-contact kinetic energy detection method based on vision measurement
TWI819914B (en) * 2022-12-06 2023-10-21 緯創資通股份有限公司 Tire size identification method, tire size identification system and computer-readable storage medium
CN116533679B (en) * 2023-06-14 2023-09-29 奇诺机器人科技(杭州)有限公司 Automatic tire changing method based on visual guidance
CN117073597B (en) * 2023-10-08 2024-01-12 青岛张氏上佳科技有限公司 Detection mechanism of gas spring piston rod assembly

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101738158B (en) * 2008-11-26 2011-11-23 软控股份有限公司 Method for measuring tyre size
RU2728848C2 (en) * 2016-04-05 2020-07-31 Пирелли Тайр С.П.А. Tire monitoring device and method
US10837920B2 (en) 2016-04-05 2020-11-17 Pirelli Tyre S.P.A. Apparatus and method for checking tyres
US11215567B2 (en) 2016-04-05 2022-01-04 Pirelli Tyre S.P.A. Apparatus and method for checking tyres

Also Published As

Publication number Publication date
CN1566903A (en) 2005-01-19

Similar Documents

Publication Publication Date Title
CN1259543C (en) Laser vision on-line automatic measuring method for tire multiple geometrical parameters
CN1250942C (en) Construction optical visual sense transducer calibration method based on plane targets
CN1259542C (en) Vision measuring method for spaced round geometrical parameters
CN108759714B (en) Coordinate system fusion and rotating shaft calibration method for multi-line laser profile sensor
CN107655898B (en) Stereoscopic scanning robot for road tunnel detection and implementation method thereof
CN1975324A (en) Double-sensor laser visual measuring system calibrating method
CN203249599U (en) Three-dimensional visual measuring instrument for load deformation of tire
CN109612390A (en) Large-size workpiece automatic measuring system based on machine vision
CN104266608B (en) Field calibration device for visual sensor and calibration method
CN102519400A (en) Large slenderness ratio shaft part straightness error detection method based on machine vision
CN105403162B (en) The automatic testing method of semitrailer outer profile size
EP3131115A1 (en) Detection method and detection device for crystal orientation of silicon wafer
JP6420639B2 (en) Tread shape measurement method
CN110763136B (en) High-precision three-dimensional workpiece size detection system and method
CN107292926A (en) Crusing robot movement locus verticality measuring method based on many image sequences
CN110455198A (en) Rectangular spline axle key based on line-structured light vision is wide and diameter measuring method
CN109781016B (en) Method for measuring high performance of automobile and the like in real time
CN1912532A (en) Three-D visual measuring quantity transmission method and plane target mark
CN109186669A (en) A kind of multi-functional automatic detection device of architectural engineering
CN108759662B (en) Vehicle overall dimension measuring method
CN101251384A (en) Method for testing ultraviolet sensor using three-axle table
CN205785101U (en) Laser three-dimensional scanning detector
CN109186489A (en) Driving device for multi-directional vision detection
CN104406540B (en) Calibration system based on point to the automobile Shape measure structure light of initial point distance constraint
CN210154538U (en) Metal structure deformation measuring device based on machine vision

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
C17 Cessation of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20060614

Termination date: 20120611