CN109759684B - Vehicle body auxiliary clamping method for assisting robot to automatically arc weld - Google Patents
Vehicle body auxiliary clamping method for assisting robot to automatically arc weld Download PDFInfo
- Publication number
- CN109759684B CN109759684B CN201811621557.1A CN201811621557A CN109759684B CN 109759684 B CN109759684 B CN 109759684B CN 201811621557 A CN201811621557 A CN 201811621557A CN 109759684 B CN109759684 B CN 109759684B
- Authority
- CN
- China
- Prior art keywords
- deviation
- welding
- assembly
- deformation
- supplied
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000003466 welding Methods 0.000 claims abstract description 170
- 238000004519 manufacturing process Methods 0.000 claims abstract description 42
- 238000013461 design Methods 0.000 claims abstract description 12
- 238000006073 displacement reaction Methods 0.000 claims description 34
- 239000011159 matrix material Substances 0.000 claims description 34
- 238000004458 analytical method Methods 0.000 claims description 21
- 230000035945 sensitivity Effects 0.000 claims description 19
- 239000000463 material Substances 0.000 claims description 18
- 239000013072 incoming material Substances 0.000 claims description 9
- 230000005489 elastic deformation Effects 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000003754 machining Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 230000003044 adaptive effect Effects 0.000 description 1
- 238000013523 data management Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Landscapes
- Resistance Welding (AREA)
- Automatic Assembly (AREA)
Abstract
The invention discloses a vehicle body auxiliary clamping method for assisting robot automatic arc welding, aiming at the situation that an empty supplied part exists in vehicle body welding, the method firstly calculates the rebound deformation of the welding seam position of a welded assembly according to the manufacturing deviation of the supplied part, and clamps the supplied part by using an auxiliary tool clamp on the premise that the value meets the tolerance design requirement; and then, an optimized model for adjusting the position of the welding line is constructed by inputting deviation source data such as manufacturing deviation of the supplied parts, positioning error of the fixture and the like, so as to obtain the optimal fixture deviation compensation quantity, and the position of the welding line is adjusted by the auxiliary tool fixture, so that the arc welding robot is ensured to weld successfully. The method is beneficial to the arc welding robot to accurately and automatically weld the target welding line according to the preset program, improves the production efficiency, reduces the manufacturing cost and has excellent engineering application value.
Description
Technical Field
The invention relates to the technical field of auxiliary welding, in particular to a vehicle body auxiliary clamping method for assisting robot automatic arc welding.
Background
In the production and manufacturing process of automobiles, the labor intensity of welding operation is high, and the working environment is severe. If manual welding is adopted, the welding quality cannot be effectively guaranteed, the produced parts have poor flexibility, and the requirements of modern automobile production cannot be met. Compared with the traditional manual welding, the welding robot is applied to welding operation, so that the production efficiency can be improved, the part quality can be optimized, and the labor condition can be improved. The common arc welding robot realizes welding of welding seams among supplied parts at fixed spatial positions under the control of a preset program.
In the trial-manufacturing stage of the vehicle body, the incoming parts of the same batch are qualified within a certain deviation range, but when the incoming parts to be welded are within the qualified range and have larger deviation compared with the standard value, the incoming parts still have larger separation, so that the arc welding robot cannot effectively weld the target welding line, the parts are reworked or scrapped, and the product quality qualified rate is influenced.
The Liu, Hu and the like of the Michigan university firstly develop the research of flexible assembly deviation analysis, the assembly of a flexible part is decomposed into four steps of positioning, clamping, welding and springback releasing, an influence coefficient method is provided on the basis of using a finite element analysis and statistical method, and a linear relation between the deviation of an input part and the springback deviation of an output assembly body is established by constructing a sensitivity matrix. Chinese patent document CN1644303A discloses a flexible welding fixture for laser welding of a rear cover of an automobile compartment, which is welded by a robot, and optimizes the design structure of the fixture, saves the space and the production cost, and accelerates the update speed of the product. Chinese patent document CN101249597A discloses a servo-controlled flexible positioning fixture, which realizes multi-degree-of-freedom adjustment, meets the characteristic requirements of producing flexible fixtures in a mixed line of various similar vehicle models, and can quickly, accurately and automatically adjust the three-dimensional spatial position and posture of a positioning pin according to the change of the positioning position of different products, so as to realize spatial positioning in different positioning modes. Chinese patent document CN201214175Y discloses a flexible fixture for automobile welding, which adopts a flexible platform with square 2 × 2 quaternary cluster holes, and adopts standard supports of different specifications to position the height, a clamping device adopts standard pins to position, and an adjusting gasket is reserved to ensure the adjusting precision in X, Y, Z three directions, thereby satisfying the trial-manufacture requirements of different automobile models, improving the reuse rate and the processing progress of the fixture, and saving the cost. Chinese patent document CN202225122U discloses a flexible fixture for analyzing assembly deviation in the tail light area of an automobile, which can adjust X, Y, Z directional displacement to adapt to the change of the new automobile structure for the analysis of assembly deviation in the trial-manufacture process of the new automobile, thereby completing the positioning and clamping of various new automobile types and facilitating the accurate analysis of assembly size deviation. "current research situation of flexible fixture for thin-wall part machining" published in 2014, 5 by Fojianyou et al, the fixture can really realize flexible clamping, namely, a set of fixture can clamp parts in any shape and size within a certain size range, and effectively overcome clamping deformation of the thin-wall part in the machining process, thereby ensuring the machining quality of the parts. The ' design and research of automobile part flexible welding fixture ' by Turkey university ' 2016 publishes a set of flexible welding fixture development method and a flexible fixture-oriented product data management method, which aims at vehicle door welding, greatly shortens the product research and development period and saves the cost. Chinese patent document CN105573248A discloses a flexible part assembly dimension deviation control method based on multi-station assembly fixture compensation, and an aircraft flexible part assembly deviation optimization algorithm based on fixture active positioning compensation, and verification of cases shows that fixture normal positioning compensation has a significant effect on reducing assembly deviation of flexible parts.
However, at the automatic arc welding stage of the vehicle body, no corresponding tool clamp scheme is provided at present for solving the problem of part spacing caused by the manufacturing deviation of supplied parts in the robot welding process.
Disclosure of Invention
The invention aims to solve the technical problem of providing a vehicle body auxiliary clamping method for assisting a robot to carry out automatic arc welding, the method solves the problem of separation between supplied parts of a vehicle body in the automatic arc welding process of the robot, clamping force is provided on two sides of a welding line to eliminate the separation between the supplied parts, meanwhile, an optimal clamp deviation compensation amount is obtained through deviation source data such as supplied part manufacturing deviation, clamp positioning error and the like, the position of the welding line is adjusted, an arc welding robot is facilitated to carry out automatic welding on a target welding line accurately according to a preset program, the welding quality and efficiency are improved, and the manufacturing cost is reduced.
In order to solve the technical problem, the auxiliary clamping method for the vehicle body for assisting the robot to automatically arc weld comprises the following steps:
clamping the incoming parts of the vehicle body through a welding fixture, and collecting manufacturing deviation data of all the incoming parts;
step two, judging the leaving phenomenon of the incoming material parts clamped on the welding fixture, if the leaving phenomenon does not occur among the incoming material parts, automatically welding a target welding line by an arc welding robot, otherwise, indicating that the incoming material parts have larger deviation compared with the standard values thereof, thereby causing the leaving phenomenon;
thirdly, calculating the resilience deformation of the welding seam position of the assembly after welding through a sensitivity matrix according to the collected manufacturing deviation data of the supplied parts;
and step four, if the rebound deformation meets the design tolerance requirement, clamping the supplied material part by using an auxiliary tool clamp, optimally calculating the chuck clamping force and normal displacement of the auxiliary tool clamp according to the supplied material part manufacturing deviation data and the auxiliary tool clamp positioning error, adjusting the chuck to adjust the clamp deviation compensation amount and the welding seam position by adjusting the hydraulic telescopic cylinder telescopic amount of the auxiliary tool clamp, eliminating the empty state of the supplied material part, automatically welding the target welding seam by an arc welding robot, and otherwise, reworking or scrapping the supplied material part.
Further, in the third step, the rebound deformation is calculated according to the following formula:
Vw＝S×Vu (1)
wherein, VwAmount of resilient deformation, V, of weld joint position for after-welding assemblyuAnd S is a sensitivity matrix of the manufacturing deviation of the supplied parts and the rebound deformation of the welding seam position of the assembly after welding.
Further, the amount of resilient deformation is determined as follows:
let V be the manufacturing deviation of supplied partsuWith a stiffness matrix of KuThe auxiliary tool clamp clamps the welding seam and eliminates the clamping force away from the welding seam chuck as FuFrom the finite element analysis, the following relationship exists between the three components:
Fu＝Ku×Vu (2)
assuming that after welding the welding seam, the rebound deformation of the welding seam position of the assembly body is VwFrom finite element analysis, the assembly welding force FwAnd a stiffness matrix K of the assembly after weldingwAnd the elastic deformation V of the weld joint position of the assembly after weldingwThe following relationships exist:
Fw＝Kw×Vw (3)
as can be seen from simple mechanical analysis, the clamping force applied to the supplied part is the same as the resilience force of the clamp after being released, namely Fu＝FwAccording to the formulas (2) and (3), a linear relationship between the manufacturing deviation of the supplied parts and the amount of resilient deformation of the weld position of the assembly after welding can be obtained:
Vw＝Ku×Vu/Kw＝S×Vu (4)
and S is a sensitivity matrix of the manufacturing deviation of the supplied parts and the rebound deformation of the welding seam position of the assembly after welding.
Further, the sensitivity matrix is obtained by using an influence coefficient method and finite element analysis, and comprises the following steps:
(1) applying unit force consistent with the deformation direction of the ith deviation source of the supplied part, obtaining deformation response of all deviation sources on the supplied part according to finite element analysis, and using a displacement deviation vector { c) of the deformation response1i,c2i,...cmi}TIndicates that if the force applied to the ith source of deviation is FuiIn time, the distortion on the corresponding source of assembly variation is expressed as:
let the force vector applied at the m sources of deviation be { Fu1,Fu2,...Fum}TExpressed, then the magnitude of the variation of the deviation at the m deviation sources is expressed as:
wherein [ V ] represents a displacement deformation vector on a deviation source, and C represents an influence coefficient method matrix;
(2) and (3) inverting the matrix [ C ] in the formula (6) to obtain the relation between the applied force vector on the supplied material part and the displacement deformation on the deviation source node:
{Fu}＝[C]-1×[V]＝[K]×[V] (7)
wherein [ K ] represents a rigidity matrix, and the specific numerical value of each column represents the force to be applied to each deviation source when unit displacement is generated at the deviation source;
(3) obtaining the force required when unit displacement occurs at the ith deviation source according to the formula (7), setting the rebound force after the auxiliary tool clamp is released to be equal to the clamping force of an incoming part when the incoming part is positioned on the clamp, and performing finite element analysis on assembly deviation again to obtain the displacement change size of the assembly body at all relation measuring point positions when unit deformation occurs at each deviation source, namely the rebound deformation amount of the assembly body; the rebound deformation of the measuring point on the assembly body at the unit displacement of the ith deviation source is expressed as:
wherein n represents the number of all measurement points on the assembly body, and for the case of non-unit displacement at the deviation source, the linear relationship between the assembly deviation and the deviation source of the supplied parts is expressed as:
wherein [ S ]]Is a sensitivity matrix between the deviation source vector and the assembly deviation vector, S in the matrixjiRepresenting the sensitivity coefficient of the deviation of the jth measuring point to the ith deviation source; judging the rebound deformation of the weld joint position of the assembly after welding (V)wAnd judging whether the design tolerance requirement is met, if the design tolerance requirement is met, clamping the supplied parts by adopting an auxiliary tool clamp, and automatically welding by using an arc welding robot.
Further, in the fourth step, the fixture deviation compensation amount is optimized by taking the minimum square sum of the position deviation of each node of the welding seam as a target function under the constraint condition, that is, the following formula is satisfied:
where, i is 1,2,. n is the weld joint, WiThe positional deviation of the weld joint.
Further, the fixture deviation compensation amount is optimized, and the method comprises the following steps:
(1) setting the deviation compensation quantity of the optimal clamp as UtThe value is the expansion amount of a hydraulic expansion cylinder of the auxiliary tool clamp, the deviation of the auxiliary tool clamp is compensated through the expansion amount of the hydraulic expansion cylinder, the position of a welding seam is adjusted, successful welding of the arc welding robot is ensured, and the optimal clamp deviation compensation amount U is obtainedtThe following relationships exist:
Ut＝U1+U2 (11)
wherein, U1For fixture positioning error deviation source data, U2For the deviation compensation quantity of the supplied material parts, under the constraint condition, the position deviation square sum of all nodes of the welding line is optimized by taking the minimum as a target function to obtain the optimal auxiliary chuck clamping force F0The constraint conditions comprise the magnitude of the clamping force of the auxiliary chuck, the normal displacement of the chuck and the position deviation of each node of the welding line, and meet the requirements of the welding process;
(2) according to equation (2), the optimum auxiliary chuck clamping force F0Substituting the formula (2) to obtain the part deviation value V at the position of the welding seam chuck0I.e. the deviation compensation quantity U of the supplied parts2Finally obtaining the optimal fixture deviation compensation Ut。
Furthermore, a hydraulic telescopic cylinder in the auxiliary tool fixture is an actuating mechanism, and the telescopic quantity x of the hydraulic telescopic cylinder is equal to the normal displacement of the auxiliary chuck, namely the optimal fixture deviation compensation quantity UtEstablishing a quantitative model of the clamping force and the expansion amount of the hydraulic expansion cylinder:
Fu＝q×x (12)
wherein, FuThe clamping force of the clamp chuck is adopted, q is a coefficient, x is the expansion amount of the hydraulic expansion cylinder, namely the welding seam position is adjusted through the clamping force of the clamp chuck.
The auxiliary clamping method for the vehicle body assisting the robot to perform automatic arc welding adopts the technical scheme, namely, aiming at the situation that the empty supplied parts exist in the vehicle body welding, the method calculates the resilience deformation of the welding seam position of the assembly after welding according to the manufacturing deviation of the supplied parts, and clamps the supplied parts by using the auxiliary tool clamp on the premise that the value meets the tolerance design requirement; and then, an optimized model for adjusting the position of the welding line is constructed by inputting deviation source data such as manufacturing deviation of the supplied parts, positioning error of the fixture and the like, so as to obtain the optimal fixture deviation compensation quantity, and the position of the welding line is adjusted by the auxiliary tool fixture, so that the arc welding robot is ensured to weld successfully. The method is beneficial to the arc welding robot to accurately and automatically weld the target welding line according to the preset program, improves the production efficiency, reduces the manufacturing cost and has excellent engineering application value.
Drawings
The invention is described in further detail below with reference to the following figures and embodiments:
fig. 1 is a block flow diagram of a vehicle body auxiliary clamping method for assisting robot automated arc welding according to the present invention.
Detailed Description
Embodiment as shown in fig. 1, the auxiliary clamping method for a vehicle body for assisting robot automatic arc welding of the present invention comprises the steps of:
clamping the incoming parts of the vehicle body through a welding fixture, and collecting manufacturing deviation data of all the incoming parts;
step two, judging the leaving phenomenon of the incoming material parts clamped on the welding fixture, if the leaving phenomenon does not occur among the incoming material parts, automatically welding a target welding line by an arc welding robot, otherwise, indicating that the incoming material parts have larger deviation compared with the standard values thereof, thereby causing the leaving phenomenon;
thirdly, calculating the resilience deformation of the welding seam position of the assembly after welding through a sensitivity matrix according to the collected manufacturing deviation data of the supplied parts;
and step four, if the rebound deformation meets the design tolerance requirement, clamping the supplied material part by using an auxiliary tool clamp, optimally calculating the chuck clamping force and normal displacement of the auxiliary tool clamp according to the supplied material part manufacturing deviation data and the auxiliary tool clamp positioning error, adjusting the chuck to adjust the clamp deviation compensation amount and the welding seam position by adjusting the hydraulic telescopic cylinder telescopic amount of the auxiliary tool clamp, eliminating the empty state of the supplied material part, automatically welding the target welding seam by an arc welding robot, and otherwise, reworking or scrapping the supplied material part.
Preferably, in the third step, the rebound deformation is calculated according to the following formula:
Vw＝S×Vu (1)
wherein, VwAmount of resilient deformation, V, of weld joint position for after-welding assemblyuFor presence of empty supply partsS is a sensitivity matrix of the manufacturing deviation of the supplied parts and the rebound deformation of the welding seam position of the assembly after welding.
Preferably, the amount of resilient deformation is determined as follows:
let V be the manufacturing deviation of supplied partsuWith a stiffness matrix of KuThe auxiliary tool clamp clamps the welding seam and eliminates the clamping force away from the welding seam chuck as FuFrom the finite element analysis, the following relationship exists between the three components:
Fu＝Ku×Vu (2)
assuming that after welding the welding seam, the rebound deformation of the welding seam position of the assembly body is VwFrom finite element analysis, the assembly welding force FwAnd a stiffness matrix K of the assembly after weldingwAnd the elastic deformation V of the weld joint position of the assembly after weldingwThe following relationships exist:
Fw＝Kw×Vw (3)
as can be seen from simple mechanical analysis, the clamping force applied to the supplied part is the same as the resilience force of the clamp after being released, namely Fu＝FwAccording to the formulas (2) and (3), a linear relationship between the manufacturing deviation of the supplied parts and the amount of resilient deformation of the weld position of the assembly after welding can be obtained:
Vw＝Ku×Vu/Kw＝S×Vu (4)
and S is a sensitivity matrix of the manufacturing deviation of the supplied parts and the rebound deformation of the welding seam position of the assembly after welding.
Preferably, the sensitivity matrix is obtained by using an influence coefficient method and finite element analysis, and comprises the following steps:
(1) applying unit force consistent with the deformation direction of the ith deviation source of the supplied part, obtaining deformation response of all deviation sources on the supplied part according to finite element analysis, and using a displacement deviation vector { c) of the deformation response1i,c2i,...cmi}TIndicates that if the force applied to the ith source of deviation is FuiIn time, the distortion on the corresponding source of assembly variation is expressed as:
let the force vector applied at the m sources of deviation be { Fu1,Fu2,...Fum}TExpressed, then the magnitude of the variation of the deviation at the m deviation sources is expressed as:
wherein [ V ] represents a displacement deformation vector on a deviation source, and C represents an influence coefficient method matrix;
(2) and (3) inverting the matrix [ C ] in the formula (6) to obtain the relation between the applied force vector on the supplied material part and the displacement deformation on the deviation source node:
{Fu}＝[C]-1×[V]＝[K]×[V] (7)
wherein [ K ] represents a rigidity matrix, and the specific numerical value of each column represents the force to be applied to each deviation source when unit displacement is generated at the deviation source;
(3) obtaining the force required when unit displacement occurs at the ith deviation source according to the formula (7), setting the rebound force after the auxiliary tool clamp is released to be equal to the clamping force of an incoming part when the incoming part is positioned on the clamp, and performing finite element analysis on assembly deviation again to obtain the displacement change size of the assembly body at all relation measuring point positions when unit deformation occurs at each deviation source, namely the rebound deformation amount of the assembly body; the rebound deformation of the measuring point on the assembly body at the unit displacement of the ith deviation source is expressed as:
wherein n represents the number of all measurement points on the assembly body, and for the case of non-unit displacement at the deviation source, the linear relationship between the assembly deviation and the deviation source of the supplied parts is expressed as:
wherein [ S ]]Is a sensitivity matrix between the deviation source vector and the assembly deviation vector, S in the matrixjiRepresenting the sensitivity coefficient of the deviation of the jth measuring point to the ith deviation source; judging the rebound deformation of the weld joint position of the assembly after welding (V)wAnd judging whether the design tolerance requirement is met, if the design tolerance requirement is met, clamping the supplied parts by adopting an auxiliary tool clamp, and automatically welding by using an arc welding robot.
Preferably, in the fourth step, the fixture deviation compensation amount is optimized according to the minimum square sum of the position deviations of each node of the weld joint as a target function under the constraint condition, that is, the following formula is satisfied:
where, i is 1,2,. n is the weld joint, WiThe positional deviation of the weld joint.
Preferably, the fixture deviation compensation amount is optimized, which includes the steps of:
(1) setting the deviation compensation quantity of the optimal clamp as UtThe value is the expansion amount of a hydraulic expansion cylinder of the auxiliary tool clamp, the deviation of the auxiliary tool clamp is compensated through the expansion amount of the hydraulic expansion cylinder, the position of a welding seam is adjusted, successful welding of the arc welding robot is ensured, and the optimal clamp deviation compensation amount U is obtainedtThe following relationships exist:
Ut＝U1+U2 (11)
wherein, U1For fixture positioning error deviation source data, U2For the deviation compensation quantity of the supplied material parts, under the constraint condition, the position deviation square sum of all nodes of the welding line is optimized by taking the minimum as a target function to obtain the optimal auxiliary chuck clamping force F0The constraint conditions comprise the magnitude of the clamping force of the auxiliary chuck and the normal direction of the chuckThe displacement and the position deviation of each node of the welding line meet the requirements of the welding process;
(2) according to equation (2), the optimum auxiliary chuck clamping force F0Substituting the formula (2) to obtain the part deviation value V at the position of the welding seam chuck0I.e. the deviation compensation quantity U of the supplied parts2Finally obtaining the optimal fixture deviation compensation Ut。
Preferably, the hydraulic telescopic cylinder in the auxiliary tool clamp is an actuating mechanism, and the telescopic quantity x of the hydraulic telescopic cylinder is equal to the normal displacement of the auxiliary chuck, namely the optimal clamp deviation compensation quantity UtEstablishing a quantitative model of the clamping force and the expansion amount of the hydraulic expansion cylinder:
Fu＝q×x (12)
wherein, FuThe clamping force of the clamp chuck is adopted, q is a coefficient, x is the expansion amount of the hydraulic expansion cylinder, namely the welding seam position is adjusted through the clamping force of the clamp chuck.
According to the method, the auxiliary chuck is used for clamping according to actual deviation states of supplied parts and the like, the supplied parts are inspected by adopting an influence coefficient method, the supplied parts meeting requirements are eliminated from being empty by adopting an auxiliary tool fixture, the positions of welding seams of the supplied parts are optimized, the fixture deviation compensation can be accurately carried out in an automatic mode in real time, the adaptive control for welding deviation is realized, the successful welding of an arc welding robot is ensured, the production efficiency is improved, and the manufacturing cost is reduced.
Claims (7)
1. A vehicle body auxiliary clamping method for assisting automatic arc welding of a robot is characterized by comprising the following steps:
clamping the incoming parts of the vehicle body through a welding fixture, and collecting manufacturing deviation data of all the incoming parts;
step two, judging the leaving phenomenon of the incoming material parts clamped on the welding fixture, if the leaving phenomenon does not occur among the incoming material parts, automatically welding a target welding line by an arc welding robot, otherwise, indicating that the incoming material parts have larger deviation compared with the standard values thereof, thereby causing the leaving phenomenon;
thirdly, calculating the resilience deformation of the welding seam position of the assembly after welding through a sensitivity matrix according to the collected manufacturing deviation data of the supplied parts;
and step four, if the rebound deformation meets the design tolerance requirement, clamping the supplied material part by using an auxiliary tool clamp, optimally calculating the chuck clamping force and normal displacement of the auxiliary tool clamp according to the supplied material part manufacturing deviation data and the auxiliary tool clamp positioning error, adjusting the chuck to adjust the clamp deviation compensation amount and the welding seam position by adjusting the hydraulic telescopic cylinder telescopic amount of the auxiliary tool clamp, eliminating the empty state of the supplied material part, automatically welding the target welding seam by an arc welding robot, and otherwise, reworking or scrapping the supplied material part.
2. The auxiliary clamping method for a vehicle body for assisting robot automated arc welding according to claim 1, characterized in that: in the third step, the rebound deformation is calculated according to the following formula:
Vw＝S×Vu (1)
wherein, VwAmount of resilient deformation, V, of weld joint position for after-welding assemblyuAnd S is a sensitivity matrix of the manufacturing deviation of the supplied parts and the rebound deformation of the welding seam position of the assembly after welding.
3. The auxiliary clamping method for a vehicle body for assisting robot automated arc welding according to claim 1 or 2, characterized in that: the rebound deformation is judged as follows:
let V be the manufacturing deviation of supplied partsuWith a stiffness matrix of KuThe auxiliary tool clamp clamps the welding seam and eliminates the clamping force away from the welding seam chuck as FuFrom the finite element analysis, the following relationship exists between the three components:
Fu＝Ku×Vu (2)
assuming that after welding the welding seam, the rebound deformation of the welding seam position of the assembly body is VwThe assembly welding force can be known from finite element analysisFwAnd a stiffness matrix K of the assembly after weldingwAnd the elastic deformation V of the weld joint position of the assembly after weldingwThe following relationships exist:
Fw＝Kw×Vw (3)
as can be seen from simple mechanical analysis, the clamping force applied to the supplied part is the same as the resilience force of the clamp after being released, namely Fu＝FwAccording to the formulas (2) and (3), a linear relationship between the manufacturing deviation of the supplied parts and the amount of resilient deformation of the weld position of the assembly after welding can be obtained:
Vw＝Ku×Vu/Kw＝S×Vu (4)
and S is a sensitivity matrix of the manufacturing deviation of the supplied parts and the rebound deformation of the welding seam position of the assembly after welding.
4. The auxiliary clamping method for a vehicle body for assisting robot automated arc welding according to claim 3, characterized in that: the sensitivity matrix is obtained by adopting an influence coefficient method and finite element analysis, and comprises the following steps:
(1) applying unit force consistent with the deformation direction of the ith deviation source of the supplied part, obtaining deformation response of all deviation sources on the supplied part according to finite element analysis, and using a displacement deviation vector { c) of the deformation response1i,c2i,...cmi}TIndicates that if the force applied to the ith source of deviation is FuiIn time, the distortion on the corresponding source of assembly variation is expressed as:
let the force vector applied at the m sources of deviation be { Fu1,Fu2,...Fum}TExpressed, then the magnitude of the variation of the deviation at the m deviation sources is expressed as:
wherein [ V ] represents a displacement deformation vector on a deviation source, and C represents an influence coefficient method matrix;
(2) and (3) inverting the matrix [ C ] in the formula (6) to obtain the relation between the applied force vector on the supplied material part and the displacement deformation on the deviation source node:
{Fu}＝[C]-1×[V]＝[K]×[V] (7)
wherein [ K ] represents a rigidity matrix, and the specific numerical value of each column represents the force to be applied to each deviation source when unit displacement is generated at the deviation source;
(3) obtaining the force required when unit displacement occurs at the ith deviation source according to the formula (7), setting the rebound force after the auxiliary tool clamp is released to be equal to the clamping force of an incoming part when the incoming part is positioned on the clamp, and performing finite element analysis on assembly deviation again to obtain the displacement change size of the assembly body at all relation measuring point positions when unit deformation occurs at each deviation source, namely the rebound deformation amount of the assembly body; the rebound deformation of the measuring point on the assembly body at the unit displacement of the ith deviation source is expressed as:
wherein n represents the number of all measurement points on the assembly body, and for the case of non-unit displacement at the deviation source, the linear relationship between the assembly deviation and the deviation source of the supplied parts is expressed as:
wherein [ S ]]Is a sensitivity matrix between the deviation source vector and the assembly deviation vector, S in the matrixjiRepresenting the sensitivity coefficient of the deviation of the jth measuring point to the ith deviation source; judging the rebound deformation of the weld joint position of the assembly after welding (V)wWhether or not the design is satisfiedAnd (5) tolerance requirements are met, the auxiliary tool fixture is adopted to clamp the supplied parts, and the arc welding robot performs automatic welding.
5. The auxiliary clamping method for a vehicle body for assisting robot automated arc welding according to claim 4, characterized in that: in the fourth step, the fixture deviation compensation quantity is optimized by taking the minimum square sum of the position deviation of each node of the welding seam as a target function under the constraint condition, namely the following formula is satisfied:
where, i is 1,2,. n is the weld joint, WiThe positional deviation of the weld joint.
6. The auxiliary clamping method for a vehicle body for assisting robot automated arc welding according to claim 5, characterized in that: optimizing the fixture deviation compensation quantity, wherein the fixture deviation compensation quantity comprises the following steps:
(1) setting the deviation compensation quantity of the optimal clamp as UtThe value is the expansion amount of a hydraulic expansion cylinder of the auxiliary tool clamp, the deviation of the auxiliary tool clamp is compensated through the expansion amount of the hydraulic expansion cylinder, the position of a welding seam is adjusted, successful welding of the arc welding robot is ensured, and the optimal clamp deviation compensation amount U is obtainedtThe following relationships exist:
Ut＝U1+U2 (11)
wherein, U1For fixture positioning error deviation source data, U2For the deviation compensation quantity of the supplied material parts, under the constraint condition, the position deviation square sum of all nodes of the welding line is optimized by taking the minimum as a target function to obtain the optimal auxiliary chuck clamping force F0The constraint conditions comprise the clamping force of the auxiliary chuck, the normal displacement of the chuck and the position deviation of each node of the welding line meeting the requirements of the welding process;
(2) according to equation (2), the optimum auxiliary chuck clamping force F0Substituting formula (2) to find zero at the position of the welding seam chuckPart offset value V0I.e. the deviation compensation quantity U of the supplied parts2Finally obtaining the optimal fixture deviation compensation Ut。
7. The auxiliary clamping method for a vehicle body for assisting robot automated arc welding according to claim 6, characterized in that: the hydraulic telescopic cylinder in the auxiliary tool fixture is an actuating mechanism, and the telescopic quantity x of the hydraulic telescopic cylinder is equal to the normal displacement of the auxiliary chuck, namely the optimal fixture deviation compensation quantity UtEstablishing a quantitative model of the clamping force and the expansion amount of the hydraulic expansion cylinder:
Fu＝q×x (12)
wherein, FuThe clamping force of the clamp chuck is adopted, q is a coefficient, x is the expansion amount of the hydraulic expansion cylinder, namely the welding seam position is adjusted through the clamping force of the clamp chuck.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811621557.1A CN109759684B (en) | 2018-12-28 | 2018-12-28 | Vehicle body auxiliary clamping method for assisting robot to automatically arc weld |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811621557.1A CN109759684B (en) | 2018-12-28 | 2018-12-28 | Vehicle body auxiliary clamping method for assisting robot to automatically arc weld |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109759684A CN109759684A (en) | 2019-05-17 |
| CN109759684B true CN109759684B (en) | 2021-03-30 |
Family
ID=66450468
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811621557.1A Active CN109759684B (en) | 2018-12-28 | 2018-12-28 | Vehicle body auxiliary clamping method for assisting robot to automatically arc weld |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109759684B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113031628B (en) * | 2021-05-26 | 2021-10-15 | 浙江华睿科技股份有限公司 | Position acquisition method of two-dimensional code, electronic device and storage medium |
| CN114603422B (en) * | 2022-03-18 | 2023-03-14 | 佛山市顺德区都信建材有限公司 | Antifouling and antiskid treatment method for ceramic tiles |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4614013A (en) * | 1984-02-21 | 1986-09-30 | David Stevenson | Method of forming a reinforced structural building panel |
| CN101670476B (en) * | 2009-09-15 | 2011-12-14 | 安徽天通达克罗涂复科技有限公司 | Levelling-free process after welding of stop workpiece and special frock thereof |
| JP2011101897A (en) * | 2009-11-12 | 2011-05-26 | Nittan Valve Co Ltd | Poppet valve seat of which is built up and method of manufacturing it |
| CN102609573B (en) * | 2012-01-18 | 2015-03-11 | 北京理工大学 | Method and device for predicting assembly dimension and form and position precision of product |
| CN103969034B (en) * | 2014-04-30 | 2016-04-27 | 中国科学院长春光学精密机械与物理研究所 | A kind of mechanical-optical setup stability assessment method resolved based on optical system misalignment rate |
| CN105527648B (en) * | 2014-09-30 | 2018-03-09 | 中国石油化工股份有限公司 | Computational methods and system for the sensitivity matrix of Anisotropic parameters inversion |
| CN106407575B (en) * | 2016-09-23 | 2019-03-26 | 南京航空航天大学 | A kind of compound material flexible component assembly Deviation Analysis Method |
-
2018
- 2018-12-28 CN CN201811621557.1A patent/CN109759684B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109759684A (en) | 2019-05-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110694828B (en) | Robot spraying track planning method based on large complex curved surface model | |
| US7974737B2 (en) | Apparatus and method of automated manufacturing | |
| CN109759684B (en) | Vehicle body auxiliary clamping method for assisting robot to automatically arc weld | |
| CN102601567B (en) | Method for welding special-shaped flange pipelines and welding tool | |
| CN109127945B (en) | Method for regulating and controlling stamping forming precision of lightweight car body covering part | |
| CN111375961B (en) | Method for determining fixture adjustment amount, body-in-white welding method and automatic fixture system | |
| CN110989490B (en) | Method for acquiring optimal installation position of workpiece based on contour error | |
| EP3134785A1 (en) | Aircraft airframe assembly | |
| CN106980742B (en) | Load projection mapping method for introducing punch forming information into finite element simulation model | |
| Elangovan et al. | Design of flexible spot welding cell for Body-In-White (BIW) assembly | |
| GB2529276A (en) | Object production | |
| CN103128147B (en) | Method and system of resilience correcting and machining of beam mold | |
| CN106584027A (en) | Process method of improving wall thickness uniformity of closed thin-walled rotary part | |
| EP3742246B1 (en) | Computer implemented method and system for generating slope synchronized tool paths for incremental sheet forming | |
| CN112157654A (en) | Optimization method for positioning error of robot machining system | |
| CN105880332A (en) | Hydraulic hollow tube springback control method and device | |
| CN107953087A (en) | A kind of manufacture method of automobile spot welding fixture | |
| CN110895634B (en) | Integrated simulation method of welding structure of 2.5 mm-thick aluminum lithium alloy T-shaped joint for accurate deformation control | |
| Todtermuschke et al. | The Fully Flexible Body Shop–A Holistic Approach for the Vehicle Production of Tomorrow | |
| Zaeh et al. | Simulation of the manufacturing process chain of welded frame structures | |
| CN204448952U (en) | Hydraulic pressure hollow pipe fitting springback control device | |
| JP2008207129A (en) | Coating tool for bumper work and method of adjusting the same | |
| Fuwen | Location issues of thin shell parts in the reconfigurable fixture for trimming operation | |
| Arunraja et al. | Optimisation of welding fixture layout for sheet metal components using DOE | |
| CN110348082A (en) | A kind of design method of toe-in control arm |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20240104 Address after: Room 1404, Building 3, Zhangzhou Zhonghai 2017P03, No. 12 Shicang South Road, Longwen District, Zhangzhou City, Fujian Province, 363000 Patentee after: Zhangzhou Longwen Shipeng Information Technology Co.,Ltd. Address before: 200093 No. 516, military road, Shanghai, Yangpu District Patentee before: University of Shanghai for Science and Technology |