CN105573248A - Flexible member assembling dimensional deviation control method based on multi-station assembly jig compensation - Google Patents

Abstract

The invention provides a flexible member assembling dimensional deviation control method based on multi-station assembly jig compensation. The flexible member assembling dimensional deviation control method is characterized in that based on a state space method for controlling the theory, a jig compensation system is added in a positioning or re-positioning link for each station, wherein the system comprises three modules: a deviation data acquisition module, a compensation scheme decision module and a compensation implementation module; the deviation data acquisition module provides input for a system; except the first station, other stations needs acquisition of the dimensional deviation values of the assembly parts after assembling of the front stations; the compensation scheme decision module is the core content, and comprises three steps: assembly deviation modeling, compensation dosage optimization model modeling, and optimal compensation dosage solution, and is used for determining the jig positioning compensation dosage for the subsequent stations so as to enable the assembly deviation of the subsequent stations to be minimum; and the compensation implementation module adjusts a jig positioning point according to a compensation decision scheme. The flexible member assembling dimensional deviation control method based on multi-station assembly jig compensation can scientifically, accurately and instantly reduce the assembly deviation for each station, and can realize station-by-station control for multi-station assembly deviation of the flexible member, and can reduce the dimensional deviation after assembling of the multi-station for the flexible member.

Description

Based on the sheet metal assembly dimensional discrepancy control method that multistation assembling jig compensates

Technical field

The present invention relates to Computer-aided manufacturing, especially a kind of flexible piece multistation assembling deviation control method, specifically a kind of sheet metal assembly dimensional discrepancy control method compensated based on multistation assembling jig.

Background technology

Flexible part owing to himself having deformable and rebound characteristics, in assembling process can by distortion overcome due to error produce gap and interference, but assembly parts can deform and produce erection stress.In Practical Project, complex product often needs to be assembled on multiple station.During conversion station, assembling deviation can transmit with the propelling of station, and builds up, and also can produce reorientation deviation because of the conversion of positioning datum simultaneously.In multistation assembling, dimensional discrepancy is excessive often causes the problems such as tolerance clearance is uneven, assembly coordination is poor, finally affects product quality.Therefore, need to use effective method to reduce flexible piece multistation assembling deviation, improve the quality of products, reduce manufacturing cost.

By transmission and the accumulation of research assembling process large deviations, some methods reducing deviation effects are widely used, and are used for reducing dimensional discrepancy for the negative effect of final assembled product quality, improve product quality.Wherein, the most general method is Robust-Design, and it plays a role at Design Stage, and reduces the susceptibility of product quality for deviation and the interference of production phase as far as possible.Another kind method adopts statistical process control tools (SPC) to detect average drifting in production run and change of error, need to use correct or regulating measures by Procedure recovery to normal service condition.But Robust-Design can only reduce the impact of deviation, directly quality can not be improved; Statistical Process Control has hysteresis quality, and can not provide the systems approach of automatic controlling dimension deviation.Statistical Process Control (SPC) needs great amount of samples to determine error source, thus can not piece by piece assembling in compensating error.These two kinds of methods above-mentioned all immediately can not reduce error in assembling process.

1996, Nguyen and Mills improved automatic, sane without Fixture assembly element, adopted various controller, the mechanical model of parts was combined with sensor readings, is used for metal-sheet parts accurately to navigate to nominal position.But it does not compensate the critical product feature deviation of final assembly by change parts position (non-nominal position), thus controls the dimensional discrepancy of parts.2006, Hu and Camelio have employed the dimensional discrepancy problem in the method solution sheet metal assembly process controlling parts error, propose a kind of adaptive control framework for control inputs parts error, measured by pre-assembled and optimize two parts and form, with deciding optimum control behavior, make critical product feature (KPC) deviation after assembling minimum.But they only give the conceptual frame of this heuristic, do not relate to the method how implementing deviation compensation; And do not consider the scope of application of the method, reluctantly for determining the controlling behavior in practical set process in the short time, if this control procedure controls for real-time online, the relation between an efficient off-line algorithm acquisition error and controlling behavior can only be needed.Lzquierdo in 2007 etc. propose a kind of actual feedback control method of assembling towards single station, can reduce the deviation of linear assembly system in real time.2012, Xie proposed a kind of compensation method of departure piece by piece for the assembling of flexible thin plate, to improve assembling deviation quality.The method comprises Off-line control module, considers the contact between part and friction, adopts realistic model to determine controlling behavior, makes the KPC deviation of assembly minimum.But based on the method for finite element simulation, need to set up realistic model for each assembly parts, there is larger limitation in real-time with for the production of in the feasibility controlled; And how to realize the stepless control of assembling deviation under not considering multistation assembly mode.

Therefore, set up a kind of Adaptive Control method being applicable to flexible piece multistation assembling process, assembling deviation is reduced by the mode implementing clamp compensation in location or reorientation link, by contributing to the assembling deviation in science, the exactly assembling of reduction flexible piece multistation, there is engineer applied and be worth.

Summary of the invention

Object of the present invention, for the problem of the Adaptive Control difference of flexible piece multistation assembling deviation, invents a kind of sheet metal assembly dimensional discrepancy control method compensated based on multistation assembling jig.

Technical scheme of the present invention is:

A kind of sheet metal assembly dimensional discrepancy control method compensated based on multistation assembling jig, it is characterized in that: first, in flexible piece multistation assembling process, by prediction, the compensation assembling deviation of station, and the fixture locating point position of participation clamp compensation can normal direction be regulated within the specific limits; Secondly, in control theory based on state-space method, in the location or reorientation link of the assembling of flexible piece multistation, add clamp compensation system carry out deviation data collection, compensation scheme optimization and compensate implementing, to reduce the assembling deviation on the station that is about to carry out assembling.That is, the present invention with anchor point normal direction flexible jig for rigging equipment, in the location or reorientation link of the assembling of flexible piece multistation, adopt the Norma l deviation regulating the method for the fixture anchor point normal direction compensation rate of subsequent work stations to reduce these station assembly parts, thus reduce the deviation of final assembly parts.Clamp compensation system for the assembling of flexible piece multistation comprises deviation data collection, compensation scheme decision-making, compensates enforcement three modules, can be realized by following technology path:

1. deviation data collection

Deviation data acquisition module is the importation of clamp compensation system.Due to the input quantity of whole assembly system, the manufacture deviation namely participating in all parts assembled is known quantity, comprises the input of the clamp compensation system of first station, and therefore first station does not need to implement deviation data collection; For other station except first station, deviation data collection refers to the dimensional discrepancy value gathering and be about to carry out subassembly that assemble, that assembled by preposition station in subsequent work stations.Using in the critical product feature (KPC) of subassembly and subsequent work stations, its fixture locating point position, assembly connection point position are as deviation data collection point, and the mode of image data comprises: being derived by the assembling deviation TRANSFER MODEL of preposition station draws and obtained by survey instrument measurement.

2. compensation scheme decision-making

Compensation scheme decision-making module is the core of clamp compensation system, comprises assembling deviation modeling, compensation quantity optimization model modeling and optimal compensation amount and solves three steps.

2.1 assembling deviation modelings

Using the normal direction compensation rate of fixture anchor point as one group of regulated variable, set up the sheet metal assembly deviation TRANSFER MODEL be about on the subsequent work stations that carries out assembling.For first station, the deviation source of consideration is the part manufacture deviation and the fixture deviations that participate in assembling; For other station except first station, the deviation source of consideration comprises the subassembly assembling deviation, part manufacture deviation and the fixture deviations that participate in assembling.Modeling process comprises location, clamping, connection, release resilience four steps, small deformation, linear elasticity is taked to suppose to the distortion of flexible piece, using critical product feature (KPC) as measuring point, use the theory of influence coefficient method set up each measuring point of flexible piece in assembling process and each deviation source be out of shape and resilience time relation.Adopt finite element software to emulate assembling process, extract super first stiffness matrix of each assembly force and distortion in location, clamping, connection and release resilience step.Finally set up fixture anchor point normal direction compensation rate, deviation transitive relation between deviation source deviation and the measuring point deviation of these station assembly parts, be the assembling deviation TRANSFER MODEL of this station.

2.2 compensation quantity optimization model modelings

According to the sheet metal assembly deviation TRANSFER MODEL above-mentioned subsequent work stations being considered fixture anchor point normal direction compensation rate, set up the assembling deviation Optimized model of this station based on clamp compensation.Optimized variable is the normal direction compensation rate of the adjustable anchor point of fixture.Optimization aim has multiple, comprising: make the quadratic sum of each measuring point deviation of these station assembly parts minimum, makes the quadratic sum of the compensation rate of each adjustable anchor point of fixture minimum.Constraint condition comprises: the compensation rate of each fixture anchor point is within certain adjustable extent, and each measuring point deviation of assembly parts requires at assembly technology within the scope of permission.

2.3 optimal compensation amounts solve

Can be obtained by assembling deviation TRANSFER MODEL: when the given one group of input deviation amount of deviation data acquisition module, deviation and the fixture anchor point normal direction compensation rate of assembly parts measuring point are linear, thus this Optimized model be solved to quadratic programming problem.Structure objective function, in the scope that constraint condition specifies, draws the optimum solution meeting optimization aim.Here need according to carrying out a point situation discussion with or without feasible solution.If there is feasible solution, then in next module according to the compensation rate of its alignment jig anchor point; If there is no feasible solution, then need to consider to adopt alternate manner to ensure assembly quality, as: consider to add new fixture anchor point etc. at this station, the specific implementation of these methods is not among research contents of the present invention.

3. compensate and implement

Compensate and implement the execution part that module is clamp compensation system.According in such scheme decision-making module to the solving result of the assembling deviation Optimized model based on clamp compensation, regulate the normal direction compensation rate of flexible jig anchor point.If alignment jig anchor point cannot meet the requirement to this station assembling deviation quality, then consider to adopt methods such as increasing fixture anchor point quantity, this content is not within practical range of the present invention.

The invention has the beneficial effects as follows: based on multistation assembling jig compensate sheet metal assembly dimensional discrepancy control method can utilize multistation assemble in location or reorientation link, according to being about to the input deviation carrying out the subsequent work stations assembled, immediately the fixture anchor point normal direction compensation rate of this station, is regulated exactly, realize the sheet metal assembly deviation Adaptive Control by station, to ensure the qualification rate of final assembled product deviation quality.

Accompanying drawing explanation

Fig. 1 adopts the flexible piece multistation assembling process schematic diagram of clamp compensation.

Fig. 2 is used for the clamp compensation system flowchart that flexible piece multistation fitted position deviation controls.

The structural representation of Fig. 3 anchor point normal direction flexible jig.

Fig. 4 flexible piece multistation is assemblied in the schematic diagram of 3-2-1 positioning stage in station k.

Fig. 5 flexible piece multistation is assemblied in the schematic diagram of N-2-1 positioning stage in station k.

Fig. 6 flexible piece multistation is assemblied in the schematic diagram of clamping phase in station k.

Fig. 7 flexible piece multistation is assemblied in the schematic diagram connecting (riveted joint) stage in station k.

Fig. 8 flexible piece multistation is assemblied in the schematic diagram discharging the riveting gun stage in station k.

Fig. 9 flexible piece multistation is assemblied in station k the schematic diagram discharging the extra anchor point stage.

Figure 10 flexible piece multistation is assemblied in the schematic diagram discharging the Planar Mechanisms anchor point stage in station k.

Embodiment

Below in conjunction with accompanying drawing and example, further description is made to the present invention.

As Figure 1-10 shows.

A kind of sheet metal assembly dimensional discrepancy control method compensated based on multistation assembling jig, it is in flexible piece multistation assembling process, by prediction, the compensation assembling deviation of station, and the fixture locating point position of participation clamp compensation can normal direction be regulated within the specific limits.Simultaneously in control theory based on state-space method, in the location or reorientation link of the assembling of flexible piece multistation, add clamp compensation system carry out deviation data collection, compensation scheme optimization and compensate implementing, to reduce the assembling deviation on the station that is about to carry out assembling.Details are as follows:

Fig. 1 gives the schematic diagram of the flexible piece multistation assembling process adopting clamp compensation, compared with the multistation assembling process of the routine using state-space method to describe, among the location of each station or reorientation link, adds clamp compensation system.Wherein, first station is with part deviation X ₀for system input, other station except first station all exports X with the assembling deviation of preposition station _k-1for system input.Through calculating, the derivation of clamp compensation system, export the normal direction compensation rate θ of this station clamp anchor point _k.In figure, k=1,2 ..., N, N represent total millwright's figure place, X ₀for the manufacture deviation of Assembly part, X _kfor the assembling deviation of station k, U _kfor station k participating in the fixture deviation of assembling, w _kfor the stochastic error of station k, in the present invention, ignore stochastic error, and the normal direction compensation rate θ of fixture anchor point _kwouldn't compensate determinacy anchor point, only consider the normal direction compensation rate of extra anchor point.Fig. 2 gives the clamp compensation system flowchart controlled for flexible piece multistation fitted position deviation, clamp compensation system comprises deviation data collection, compensation scheme decision-making, compensates enforcement three modules, below for station k, function and content for each module provides detailed description, might as well establish k ≠ 1 here.Fig. 3 gives the structural representation of anchor point normal direction flexible jig, when specifically implementing, and also can designed, designed corresponding anchor point normal direction flexible jig or realized with reference to correlative theses and the anchor point normal direction flexible jig disclosed in patent as required.

1. deviation data collection

Deviation data acquisition module is the method by measuring or calculating, and obtains the output bias of station (k-1), and the input of clamp compensation system in this, as station k.Because measurements and calculations result all exists inevitable error, therefore the output bias of the station (k-1) obtained by this module acquires and its actual value X _k-1between there is error, the deviate that this module obtains is designated as X ' here _k-1.X ' _k-1in comprise the subassembly assembled through preposition station assembling deviation, be about to participate in station k the part assembled manufacture deviation, in station k, also do not participate in the manufacture deviation of part to be assembled that assembles.Manufacture deviation due to part has been contained in the input quantity X of whole assembly system ₀in, need the data gathered to be assembling deviations of the flexible subassembly assembled by station (k-1) here, this subassembly is designated as A ^k.By this subassembly A ^kcritical product feature (KPC) and station k in A ^kfixture locating point position, tie point (riveting point) position Norma l deviation as deviation data acquisition target, this Norma l deviation value refers to the normal component of the deviate of flexible piece data collection point and its nominal position, can be obtained by two kinds of modes: first, after station (k-1) has assembled, survey instrument (as laser tracker) is adopted directly to measure subassembly A ^kobtain; Second, derived by the assembling deviation TRANSFER MODEL of station (k-1) and obtain, the derivation of the flexible piece deviation TRANSFER MODEL of different station is similar, be divided into location, clamping, connect and release resilience four steps, detailed process can see the assembling deviation modeling in program decisions module.The A obtained ^kv is designated as at the Norma l deviation of data collection point _a.In addition, the flexible part being about to participate in assembling in station k is designated as P ^k, the Norma l deviation of its KPC point is designated as V _p.

2. compensation scheme decision-making

2.1 assembling deviation modelings

Set up on station k and consider fixture extra anchor point normal direction compensation rate θ _ksheet metal assembly deviation TRANSFER MODEL, need the deviation source considered to have: assembling deviation, the manufacture deviation of part, the deviations of fixture of subassembly participating in assembling.By subassembly A ^kwith part P ^kkPC point as measuring point, its deviation is designated as V respectively _amand V _pm.A ^kand P ^kin station k, the deviation of extra locating point position is designated as V respectively _aaand V _pa, the deviation of assembly connection point position is designated as V respectively _ajand V _pj.A might as well be established ^kand P ^kmeasuring point, extra anchor point and assembly connection point position do not overlap mutually.

Resilience four steps can be located, clamp, connect and be discharged to sheet metal assembly bias modeling respectively, under the hypothesis based on small deformation, linear elasticity, uses influence coefficient method and super first rigidity theory to set up the assembling deviation TRANSFER MODEL of station k.

(1) locate

For ensureing assembling rigidity and accuracy, flexible piece location is general adopts " N-2-1 " Planar Mechanisms location, its position fixing process can be divided into two stages: the first stage, adopt based on rigid model really qualitative positioning method determinacy location (i.e. 3-2-1 locate) is carried out to flexible part, this is the process of one degree of freedom Complete Bind, and flexible piece does not deform; Subordinate phase, in order to reduce the error that flexible piece causes due to self-deformation, need extra anchor point is added on the basis of locating at " 3-2-1 ", form Planar Mechanisms location (namely " N-2-1 " locates), now flexible piece deforms.

A) determinacy location

In determinacy positioning analysis, suppose that all subassemblies and part are rigid body, its deviations is located the change of rear space pose by rigid body part and is caused.Here, determinacy positioning analysis uses rigid motion theory, sets up the relation between the assembling deviation of pose deviation and the subassembly participating in the parts assembled, part manufacture deviation, fixture anchor point deviation.

6 degree of freedom of Arbitrary 3 D part by 6 locating piece Complete Binds, can realize 3-2-1 determinacy location.Now, the fixture occurred because of locating piece place and part deviation and on the part that causes the deviation of any point can be calculated by formula (1):

δq _o＝J ^-1·N·δR(1)

Wherein, δ q _o=[o _x, o _y, o _z, δ α, δ β, δ γ] ^t, represent the shifting deviation [o at any point o place on part _x, o _y, o _z] ^twith rotating deviation [δ α, δ β, δ γ] ^t; J=[J ₁, J ₂..., J ₆] ^t, represent the Jacobian matrix of positioning block of clamp, and the Jacobian matrix of i-th positioning block of clamp is J _i=[n _ix, n _iy, n _iz, n _izy _i-n _iyz _i, n _ixz _i-n _izx _i, n _iyx _i-n _ixy _i], wherein, the coordinate of i-th positioning block of clamp is (x _i, y _i, z _i), n _i=[n _ix, n _iy, n _iz] ^t(i=1,2 ..., 6) and be the unit normal vector of the piece surface at this positioning block of clamp place; δ R=[δ r ₁, δ r ₂..., δ r ₆] ^t, represent fixture deviations and part manufacture deviation (assembling deviation of the subassembly) sum at 6 positioning block of clamp places, wherein, δ r _i=[δ x _i, δ y _i, δ z _i] ^t;

As shown in Figure 4, subassembly A ^kwith part P ^kbe in determinacy positioning stage respectively, their Norma l deviation is the deviation in z direction.Now, A ^kand P ^kthe Norma l deviation at each point place needs superposition fixture deviations on the impact of this point.Known flexible part A ^kand P ^kthe deviation of fixture determinacy anchor point is respectively V _aJdand V _pJd, on the flexible piece caused thus, the Norma l deviation (i.e. the z deviation of directivity) of arbitrfary point can calculate with formula (1).In determinacy positioning stage, flexible piece A ^kand P ^kthe measuring point deviation caused by determinacy anchor point deviation is designated as V respectively _{am (d)}and V _{pm (d)}, in station k, the deviation of extra locating point position is designated as V respectively _{aa (d)}and V _{pa (d)}, the deviation of assembly connection point (riveting point) position is designated as V respectively _{aj (d)}and V _{pj (d)}.Subassembly A after deviation accumulation ^kthe deviation of upper each point is:

V _Am(1)＝V _Am+V _Am(d)(2)

V _Aa(1)＝V _Aa+V _Aa(d)(3)

V _Aj(1)＝V _Aj+V _Aj(d)(4)

Part P ^kthe deviation of upper each point is:

V _Pm(1)＝V _Pm+V _Pm(d)(5)

V _Pa(1)＝V _Pa+V _Pa(d)(6)

V _Pj(1)＝V _Pj+V _Pj(d)(7)

B) extra anchor point is added

As shown in Figure 5, after applying extra anchor point, subassembly A ^kwith part P ^kform " N-2-1 " Planar Mechanisms location, flexible piece A ^kand P ^kdeform, and be 0 in the deviation at extra anchor point place.If now at A ^kand P ^kextra anchor point place introduce fixture normal direction compensation rate θ respectively _aand θ _p, then in the interpolation extra anchor point stage, A ^kand P ^kθ is respectively in the deviation at extra anchor point place _aand θ _p.To flexible piece A ^kand P ^kdo linear elasticity, small deformation hypothesis, use influence coefficient method and super first rigidity theory, set up this compliant element and stressed relation.Below with subassembly A ^kfor example is analyzed:

F _Aa＝K _Aa(V _AJa+θ _A-V _Aa(1))(8)

In formula, F _aafor flexible subassembly A ^kin the power that its extra anchor point place is subject to; K _aafor extracted by finite element software with " 3-2-1 " determinacy position constraint for boundary condition, extra anchor point be key point set up super first stiffness matrix; V _aJafor the fixture deviation at extra anchor point place.

When at subassembly A ^kextra anchor point place apply power F _aa, after forming " N-2-1 " location, cause A ^kdeform, the deviation that in this stage, its measuring point and tie point position produce is:

V _Am(a)＝C _Am(a)F _Aa(9)

V _Aj(a)＝C _Aj(a)F _Aa(10)

Wherein, V _{am (a)}and V _{aj (a)}be respectively and add in the extra anchor point stage, subassembly A ^kat the Norma l deviation that measuring point and tie point place produce.C _{am (a)}and C _{aj (a)}be respectively A ^kthe holding force be subject at extra anchor point place and its measuring point deviation V _{am (a)}with tie point deviation V _{aj (a)}between linear system matrix, this linear system matrix can by stiffness matrix derive obtain.

By V _{am (a)}and V _{aj (a)}be added to subassembly A ^kin the deviation at measuring point and tie point place, obtaining this stage terminates rear A ^kat the deviation V at measuring point and tie point place _{am (2)}and V _{aj (2)}be respectively:

V _Am(2)＝V _Am(1)+V _Am(a)(11)

V _Aj(2)＝V _Aj(1)+V _Aj(a)(12)

According to said method, in like manner part P can be obtained ^kin the interpolation extra anchor point stage, at the power F that its extra anchor point place is subject to _pa, and at the Norma l deviation V that measuring point and tie point place produce _{pm (a)}and V _{pj (a)}.

F _Pa＝K _Pa(V _PJa+θ _P-V _Pa(1))(13)

V _Pm(a)＝C _Pm(a)F _Pa(14)

V _Pj(a)＝C _Pj(a)F _Pa(15)

Wherein, K _paunder " 3-2-1 " determinacy position constraint, part P ^ksuper first stiffness matrix at extra anchor point place; V _pJafor the fixture deviation at extra anchor point place.C _{pm (a)}and C _{pj (a)}be respectively P ^kat the power F that extra anchor point place is subject to _pawith its measuring point deviation V _{pm (a)}with tie point deviation V _{pj (a)}between linear system matrix.

Add after the extra anchor point stage terminates, P ^kat the deviation V at measuring point and tie point place _{pm (2)}and V _{pj (2)}be respectively:

V _Pm(2)＝V _Pm(1)+V _Pm(a)(16)

V _Pj(2)＝V _Pj(1)+V _Pj(a)(17)

(2) clamp

Subassembly A ^kwith part P ^kafter completing " N-2-1 " location, riveting gun applies snap-in force at its assembly connection point place, and accommodate tie point (riveting point) to nominal position, namely the deviation at tie point place is respectively by V _{aj (2)}and V _{pj (2)}become 0, as shown in Figure 6.Under the effect of riveting gun snap-in force, flexible piece A ^kand P ^kdeform further, now, tie point place is stressed can be expressed as with deformation relationship:

F _j＝F _Aj+F _Pj(18)

In formula, F _jrepresent the snap-in force that riveting gun applies at tie point place, F _ajand F _pjbe respectively flexible piece A ^kand P ^kin the riveting gun snap-in force suffered by assembly connection point.Under being located at " N-2-1 " position constraint, flexible piece A ^kand P ^ksuper first stiffness matrix at tie point place be K _ajand K _pj, then have:

F _Aj＝-K _AjV _Aj(2)(19)

F _Pj＝-K _PjV _Pj(2)(20)

In clamping phase, flexible piece A ^kand P ^kthe deviation that produces of measuring point place and the snap-in force that is subject to of its tie point place there is linear relationship, can be derived by the stiffness matrix in this stage.By the A caused by riveting gun snap-in force ^kand P ^kthe deviation at measuring point place is designated as V respectively _{am (j)}and V _{pm (j)}, A ^kat the power F that tie point place is subject to _ajwith its measuring point deviation V _{am (j)}between linear system matrix be designated as C _{am (j)}, P ^kat the power F that tie point place is subject to _pjwith its measuring point deviation V _{pm (j)}between linear system matrix be designated as C _{pm (j)}, then have:

V _Am(j)＝C _Am(j)F _Aj(21)

V _Pm(j)＝C _Pm(j)F _Pj(22)

By V _{am (j)}and V _{pm (j)}be added to subassembly A respectively ^kwith part P ^kin the deviation at measuring point place, obtain clamping phase and terminate rear A ^kand P ^kat the deviation V at its measuring point place _{am (3)}and V _{pm (3)}be respectively:

V _Am(3)＝V _Am(2)+V _Am(j)(23)

V _Pm(3)＝V _Pm(2)+V _Pm(j)(24)

(3) (riveted joint) is connected

In access phase, fastening means can be connected by welding, riveted joint etc., each flexible parts are connected to become assembly parts.For convenience of description, riveting method might as well be selected here to flexible piece A ^kand P ^kconnect.

As shown in Figure 7, in this stage, at A ^kand P ^kthe riveting gun holding force that tie point position applies does not discharge, and uses riveting gun that two flexible pieces are riveted together.Riveting gun, due to reasons such as wearing and tearing, there will be deviation in riveting process, has an impact to last assembly parts deviation.Here modeling process puts aside riveting gun deviation.Now, flexible piece A ^kand P ^kall be subject to blessing power at its extra anchor point and tie point position, and its deviation does not change.After riveting gun is riveted together two flexible pieces, its stiffness matrix is assembly parts A ^k+1stiffness matrix, be different from subassembly A ^kwith part P ^kstiffness matrix.

(4) resilience is discharged

Owing to being subject to the blessing power of extra anchor point and the blessing power effect of riveting gun in flexible piece location, clamping process, deforming, there is internal stress, after discharging riveting gun and extra anchor point, can there is resilience in flexible assembly part under internal stress effect.Now, flexible assembly part is still by two groups of " 3-2-1 " determinacy anchor point constraints, and be in Planar Mechanisms state, part anchor point should be discharged, make it become determinacy positioning states, flexible assembly part also resilience can occur in this course.

A) riveting gun is discharged

As shown in Figure 8, this stage release riveting gun, namely discharges the snap-in force of riveting gun at tie point place.Based on linear elasticity, small deformation hypothesis, be similar to and think that screen resilience equals the counter-force of snap-in force, i.e. flexible assembly part A ^k+1the screen resilience F produced because of riveting gun release at tie point place _sjfor:

F _sj＝-F _j(25)

Under this screen resilience effect, flexible assembly part A ^k+1deform, now, tie point place is stressed can be expressed as with deformation relationship:

F _sj＝K _sjV _j(sj)(26)

Wherein, K _sjrepresent at subassembly A ^kwith part P ^ktwo groups of " N-2-1 " position constraints under, assembly parts A ^k+1super first stiffness matrix at tie point place.V _{j (sj)}for in the release riveting gun stage, A ^k+1the Norma l deviation produced at tie point place.Because the Accumulated deviation at tie point place is on last stage 0, therefore V _{j (sj)}being this stage terminates rear assembly parts A ^k+1at the deviation V at tie point place _{j (4)}, that is:

V _j(4)＝V _j(sj)(27)

Assembly parts A ^k+1measuring point be subassembly A ^kmeasuring point and part P ^kthe set of measuring point.In this stage, discharged the A caused by riveting gun ^k+1the Norma l deviation produced at measuring point place is designated as V _{m (sj)}, and have $V_{m\left(sj\right)}=\left[\begin{array}{c}{V}_{Am\left(sj\right)}\\ V_{Pm\left(sj\right)}\end{array}\right],$ Wherein, V _{am (sj)}and V _{pm (sj)}be respectively A ^kand P ^kmeasuring point place produce deviation.

V _m(sj)＝C _m(sj)F _sj(28)

In formula, C _{m (sj)}for A ^k+1the screen resilience F be subject at tie point place _sjwith its measuring point deviation V _{m (sj)}between linear system matrix, and $C_{m\left(sj\right)}=\left[\begin{array}{c}{C}_{Am\left(sj\right)}\\ C_{Pm\left(sj\right)}\end{array}\right],$ Wherein, C _{am (sj)}for F _sjwith subassembly A ^kmeasuring point deviation V _{am (sj)}between linear system matrix, C _{pm (sj)}for F _sjwith part P ^kmeasuring point deviation V _{pm (sj)}between linear system matrix, then have:

V _Am(sj)＝C _Am(sj)F _sj(29)

V _Pm(sj)＝C _Pm(sj)F _sj(30)

By V _{am (sj)}and V _{pm (sj)}be added to subassembly A respectively ^kwith part P ^kmeasuring point place deviation in, obtain release the riveting gun stage terminate rear A ^kand P ^kthe deviation V at measuring point place _{am (4)}and V _{pm (4)}be respectively:

V _Am(4)＝V _Am(3)+V _Am(sj)(31)

V _Pm(4)＝V _Pm(3)+V _Pm(sj)(32)

B) extra anchor point is discharged

As shown in Figure 9, this stage release subassembly A ^kwith part P ^kextra anchor point, namely discharge the blessing power at extra anchor point place.Based on linear elasticity, small deformation hypothesis, be similar to and think that screen resilience equals the counter-force of snap-in force, i.e. flexible assembly part A ^k+1because of A ^kand P ^kthe release of extra anchor point and the screen resilience F that produces _asaand F _psabe respectively:

F _Asa＝-F _Aa(33)

F _Psa＝-F _Pa(34)

At screen resilience F _asaand F _psaeffect under, flexible assembly part A ^k+1deform further.Now, A is not considered ^kand P ^kthe screen resilience F at extra anchor point place _asaand F _psarelease order, then A ^kthe distortion at extra anchor point place can be thought and equals by A ^kextra anchor point place screen resilience F _asathis point deformation superposition caused is by P ^kextra anchor point place screen resilience F _psathis point deformation caused.

Then A ^kstressed and the deformation relationship at extra anchor point place can be expressed as:

V _Aa(sa)＝K _Asa ^-1F _Asa+C _{Aa_P(sa)}F _Psa(35)

Wherein, K _asarepresent A ^k+1at subassembly A ^kwith part P ^ktwo groups of " 3-2-1 " position constraints under, A ^ksuper first stiffness matrix at extra anchor point place.C _{aa_P (sa)}represent A ^k+1at P ^kthe screen resilience F that is subject to of extra anchor point place _psawith by F _psathe A caused ^klinear system matrix between extra anchor point deviation.V _{aa (sa)}for discharging in the extra anchor point stage, A ^k+1at A ^kthe Norma l deviation that produces of extra anchor point place.

Similarly, P ^kthe distortion at extra anchor point place can be thought and equals by P ^kextra anchor point place screen resilience F _psathis point deformation superposition caused is by A ^kextra anchor point place screen resilience F _asathis point deformation caused, then P ^kstressed and the deformation relationship at extra anchor point place can be expressed as:

V _Pa(sa)＝K _Psa ^-1F _Psa+C _{Pa_A(sa)}F _Asa(36)

Wherein, K _psarepresent A ^k+1at subassembly A ^kwith part P ^ktwo groups of " 3-2-1 " position constraints under, P ^ksuper first stiffness matrix at extra anchor point place.C _{pa_A (sa)}represent A ^k+1at A ^kthe screen resilience F that is subject to of extra anchor point place _asawith by F _asathe P caused ^klinear system matrix between extra anchor point deviation.V _{pa (sa)}for discharging in the extra anchor point stage, A ^k+1at P ^kthe Norma l deviation that produces of extra anchor point place.

At the end of on last stage, the Accumulated deviation at fixture extra anchor point place is fixture deviation and the clamp compensation amount sum of extra anchor point.The deviation that this stage produces is accumulated, obtains after this stage terminates, A ^k+1at A ^kand P ^kthe deviation V of extra locating point position _{aa (5)}and V _{pa (5)}.

V _Aa(5)＝V _AJa+θ _A+V _Aa(sa)(37)

V _Pa(5)＝V _PJa+θ _P+V _Pa(sa)(38)

In the release extra anchor point stage, due to subassembly A ^kextra anchor point discharge the assembly parts A caused ^k+1the Norma l deviation produced at measuring point place is designated as V _{m_A (sa)}, and have $V_{m\_A\left(sa\right)}=\left[\begin{array}{c}{V}_{Am\_A\left(sa\right)}\\ V_{Pm\_A\left(sa\right)}\end{array}\right],$ Wherein, V _{am_A (sa)}and V _{pm_A (sa)}the A caused thus respectively ^kthe deviation at measuring point place and P ^kthe deviation at measuring point place; Due to part P ^kextra anchor point discharge the assembly parts A caused ^k+1the Norma l deviation produced at measuring point place is designated as V _{m_P (sa)}, and have $V_{m\_P\left(sa\right)}=\left[\begin{array}{c}{V}_{Am\_P\left(sa\right)}\\ V_{Pm\_P\left(sa\right)}\end{array}\right],$ Wherein, V _{am_P (sa)}and V _{pm_P (sa)}the A caused thus respectively ^kthe deviation at measuring point place and P ^kthe deviation at measuring point place.

In this stage, assembly parts A ^k+1the deviation V produced at measuring point place _{m (sa)}equal by A ^kand P ^kextra anchor point discharge the deviation V at the measuring point place caused _{m_A (sa)}, V _{m_P (sa)}sum, that is:

V _m(sa)＝V _{m_A(sa)}+V _{m_P(sa)}(39)

V _{m_A(sa)}＝C _{m_A(sa)}F _Asa(40)

V _{m_P(sa)}＝C _{m_P(sa)}F _Psa(41)

In formula, C _{m_A (sa)}for A ^k+1at A ^kthe screen resilience F that is subject to of extra anchor point place _asawith its measuring point deviation V _{m_A (sa)}between linear system matrix, and $C_{m\_A\left(sa\right)}=\left[\begin{array}{c}{C}_{Am\_A\left(sa\right)}\\ C_{Pm\_A\left(sa\right)}\end{array}\right],$ Wherein, C _{am_A (sa)}for F _asawith subassembly A ^kmeasuring point deviation V _{am_A (sa)}between linear system matrix, C _{pm_A (sa)}for F _asawith part P ^kmeasuring point deviation V _{pm_A (sa)}between linear system matrix; C _{m_P (sa)}for A ^k+1at P ^kthe screen resilience F that is subject to of extra anchor point place _psawith its measuring point deviation V _{m_P (sa)}between linear system matrix, and $C_{m\_P\left(sa\right)}=\left[\begin{array}{c}{C}_{Am\_P\left(sa\right)}\\ C_{Pm\_P\left(sa\right)}\end{array}\right],$ Wherein, C _{am_P (sa)}for F _psawith subassembly A ^kmeasuring point deviation V _{am_P (sa)}between linear system matrix, C _{pm_P (sa)}for F _psawith part P ^kmeasuring point deviation V _{pm_P (sa)}between linear system matrix, then have:

V _{Am_A(sa)}＝C _{Am_A(sa)}F _Asa(42)

V _{Pm_A(sa)}＝C _{Pm_A(sa)}F _Asa(43)

V _{Am_P(sa)}＝C _{Am_P(sa)}F _Psa(44)

V _{Pm_P(sa)}＝C _{Pm_P(sa)}F _Psa(45)

Convolution (39) can obtain, the A produced in this stage ^kand P ^kthe deviation at measuring point place is:

V _Am(sa)＝V _{Am_A(sa)}+V _{Am_P(sa)}(46)

V _Pm(sa)＝V _{Pm_A(sa)}+V _{Pm_P(sa)}(47)

By V _{am (sa)}and V _{pm (sa)}be added to subassembly A respectively ^kwith part P ^kmeasuring point place deviation in, obtaining discharging the extra anchor point stage terminates rear A ^kand P ^kthe deviation V at measuring point place _{am (5)}and V _{pm (5)}be respectively:

V _Am(5)＝V _Am(4)+V _Am(sa)(48)

V _Pm(5)＝V _Pm(4)+V _Pm(sa)(49)

In like manner, in this stage, assembly parts A ^k+1the deviation V produced at tie point place _{j (sa)}equal by A ^kand P ^kextra anchor point discharge the deviation V of the junction caused _{j_A (sa)}, V _{j_P (sa)}sum, that is:

V _j(sa)＝V _{j_A(sa)}+V _{j_P(sa)}(50)

V _{j_A(sa)}＝C _{j_A(sa)}F _Asa(51)

V _{j_P(sa)}＝C _{j_P(sa)}F _Psa(52)

In formula, C _{j_A (sa)}for A ^k+1at A ^kthe screen resilience F that is subject to of extra anchor point place _asawith its tie point deviation V _{j_A (sa)}between linear system matrix, C _{j_P (sa)}for A ^k+1at P ^kthe screen resilience F that is subject to of extra anchor point place _asawith its tie point deviation V _{j_P (sa)}between linear system matrix.

By V _{j (sa)}be added to assembly parts A ^k+1tie point place deviation in, obtain discharging the extra anchor point stage terminate after the deviation V at its tie point place _{j (5)}for:

V _j(5)＝V _j(4)+V _j(sa)(53)

C) assembly parts Planar Mechanisms anchor point is discharged

Due to subassembly A ^kwith part P ^krespectively there is one group of " 3-2-1 " determinacy location, so, after release riveting gun and release extra anchor point stage terminate, flexible assembly part A ^k+1still by two groups of " 3-2-1 " determinacy anchor point constraints, be in Planar Mechanisms state, its internal stress still exists.When release portion anchor point, make assembly parts A ^k+1when forming determinacy positioning states, can there is resilience because of internal stresses release in this flexible assembly part.

Here part P might as well be discharged ^k" 3-2-1 " determinacy anchor point, as shown in Figure 10.At release Planar Mechanisms anchor point, i.e. part P ^k" 3-2-1 " determinacy anchor point before, P ^krestrained condition identical with determinacy positioning stage, all by the constraint of 6 locating pieces.Due to the existence of preposition station assembling deviation, part manufacture deviation and fixture deviations, part P ^kwith subassembly A ^kafter connecting (riveted joint), there is assembly deflections, make P ^k6 locating pieces it is existed to the effect of power.If discharge this 6 locating pieces, be namely equivalent at assembly parts A ^k+1position corresponding to these locating pieces apply reverse acting force, then assembly parts A ^k+1generation be out of shape, assembling deviation will be accumulated further.

The Norma l deviation direction of measuring point and assembly parts A ^k+1the method direction of principal plane consistent.In the release assembly parts Planar Mechanisms anchor point stage, the Norma l deviation that measuring point place produces main be positioned at assembly parts principal plane and (be part P ^kprincipal plane) the release of 3 locating pieces be correlated with, ignore the impact that other 3 locating pieces releases produce.

The holding power of locating piece and part P ^kwith subassembly A ^kbetween interaction force relevant.First before calculated constraint anchor point release, assembly connection point virgin assembly parts A ^kto part P ^knormal force F _{p_A (5)}.If K _{p_A (1)}for part P ^kwith " 3-2-1 " determinacy position constraint for boundary condition, tie point is super first stiffness matrix that key point is set up.Then normal force F _{p_A (5)}equal part P ^ktie point the position change of deviation and P before and after riveted joint ^kstiffness matrix K _{p_A (1)}long-pending, that is:

F _{P_A(5)}＝K _{P_A(1)}(V _j(5)-V _Pj(1))(54)

Then by part P ^kthe normal force F be subject at tie point place _{p_A (5)}, P before calculated constraint anchor point release ^kprincipal plane 3 locating pieces are to assembly parts A ^k+1the directed force F applied _{pJd (5)}.

F _PJd(5)＝C _PJd(1)F _{P_A(5)}(55)

Wherein, C _{pJd (1)}for reaction A ^kto P ^kdirected force F _{p_A (5)}and P ^kprincipal plane locating piece directed force F _{pJd (5)}between the linear system matrix of relation, can part P be passed through ^kunder determinacy position constraint, super first stiffness matrix at tie point and principal plane locating piece place is derived and is obtained.

As release assembly parts A ^k+1planar Mechanisms anchor point, i.e. part P ^kreally, during qualitative positioning point, its principal plane locating piece place will produce screen resilience F _sd, before being approximately equal to release, principal plane locating piece is to A ^k+1directed force F _{pJd (5)}counter-force, that is:

F _sd＝-F _PJd(5)(56)

At screen resilience F _sdeffect under, flexible assembly part A ^k+1deform further.Now, then A ^k+1at P ^kprincipal plane locating piece place is because of screen resilience F _sdeffect and the deviation V that causes _{pd (sd)}for:

V _Pd(sd)＝K _sd ^-1F _sd(57)

Wherein, K _sdrepresent A ^k+1at subassembly A ^k" 3-2-1 " position constraint under, P ^ksuper first stiffness matrix at principal plane locating piece place.

At the end of on last stage, P ^kthe Accumulated deviation at principal plane locating piece place be corresponding fixture deviation, be designated as V _{pJd_z}, be part P ^kreally qualitative positioning point deviation V _pJdsubset.The deviation that this stage produces is accumulated, obtains after this stage terminates, A ^k+1at P ^kthe deviation V of principal plane locating piece position _{pd (6)}.

V _Pd(6)＝V _{PJd_z}+V _Pd(sd)(58)

In the release assembly parts Planar Mechanisms anchor point stage, by part P ^kthe screen resilience F at principal plane locating piece place _sdthe assembly parts A caused ^k+1the Norma l deviation produced at measuring point place is designated as V _{m (sd)}, and have $V_{m\left(sd\right)}=\left[\begin{array}{c}{V}_{Am\left(sd\right)}\\ V_{Pm\left(sd\right)}\end{array}\right],$ Wherein, V _{am (sd)}and V _{pm (sd)}be respectively the A caused thus ^kand P ^kmeasuring point place produce deviation.

V _m(sd)＝C _m(sd)F _sd(59)

In formula, C _{m (sd)}for A ^k+1at P ^kthe screen resilience F that is subject to of principal plane locating piece place _sdwith its measuring point deviation V _{m (sd)}between linear system matrix, and $C_{m\left(sd\right)}=\left[\begin{array}{c}{C}_{Am\left(sd\right)}\\ C_{Pm\left(sd\right)}\end{array}\right],$ Wherein, C _{am (sd)}for F _sdwith subassembly A ^kmeasuring point Norma l deviation V _{am (sd)}between linear system matrix, C _{pm (sd)}for F _sdwith part P ^kmeasuring point Norma l deviation V _{pm (sd)}between linear system matrix, then have:

V _Am(sd)＝C _Am(sd)F _sd(60)

V _Pm(sd)＝C _Pm(sd)F _sd(61)

By V _{am (sd)}and V _{pm (sd)}be added to subassembly A respectively ^kwith part P ^kmeasuring point place deviation in, obtain release release the assembly parts Planar Mechanisms anchor point stage terminate rear A ^kand P ^kthe deviation V at measuring point place _{am (6)}and V _{pm (6)}be respectively:

V _Am(6)＝V _Am(5)+V _Am(sd)(62)

V _Pm(6)＝V _Pm(5)+V _Pm(sd)(63)

According to said method, in like manner can obtain in this stage, the A caused by the release of assembly parts Planar Mechanisms anchor point ^k+1the deviation V at tie point place _{j (sd)}, and A ^kand P ^kthe deviation V at extra anchor point place _{aa (sd)}and V _{pa (sd)}.

V _j(sd)＝C _j(sd)F _sd(64)

V _Aa(sd)＝C _Aa(sd)F _sd(65)

V _Pa(sd)＝C _Pa(sd)F _sd(66)

In formula, C _{j (sd)}for A ^k+1at P ^kthe screen resilience F that is subject to of principal plane locating piece place _sdwith its tie point Norma l deviation V _{j (sd)}between linear system matrix, C _{aa (sd)}for F _sdwith subassembly A ^kextra anchor point Norma l deviation V _{aa (sd)}between linear system matrix, C _{pa (sd)}for F _sdwith part P ^kextra anchor point Norma l deviation V _{pa (sd)}between linear system matrix.

After the release assembly parts Planar Mechanisms anchor point stage terminates, A ^k+1the deviation V at tie point place _{j (6)}, and A ^kand P ^kthe deviation V at extra anchor point place _{aa (6)}and V _{pa (6)}be respectively:

V _j(6)＝V _j(5)+V _j(sd)(67)

V _Aa(6)＝V _Aa(5)+V _Aa(sd)(68)

V _Pa(6)＝V _Pa(5)+V _Pa(sd)(69)

To sum up, when station k has assembled, assembly parts A ^k+1the final Norma l deviation at measuring point place is V _{am (6)}and V _{pm (6)}, the final Norma l deviation at tie point place is V _{j (6)}, A ^kand P ^kthe final Norma l deviation at extra anchor point place is respectively V _{aa (6)}and V _{pa (6)}, P ^kthe final Norma l deviation at principal plane locating piece place is V _{pd (6)}.Can obtain through arrangement:

V _Am(6)＝V _Am+V _Am(d)+(C _Am(a)-C _{Am_A(sa)}+C _Am(sd)C _PJd(1)K _{P_A(1)}C _{j_A(sa)})K _Aa(V _AJa+θ _A-V _Aa-V _Aa(d))

+(C _Am(sj)-C _Am(j)-C _Am(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _Aj[V _Aj+V _Aj(d)+C _Aj(a)K _Aa(V _AJa+θ _A-V _Aa-V _Aa(d))]

+(C _Am(sj)-C _Am(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _Pj[V _Pj+V _Pj(d)+C _Pj(a)K _Pa(V _PJa+θ _P-V _Pa-V _Pa(d))]

+(-C _{Am_P(sa)}+C _Am(sd)C _PJd(1)K _{P_A(1)}C _{j_P(sa)})K _Pa(V _PJa+θ _P-V _Pa-V _Pa(d))

+C _Am(sd)C _PJd(1)K _{P_A(1)}(V _Pj+V _Pj(d))

(70)

V _Pm(6)＝V _Pm+V _Pm(d)+(C _Pm(a)-C _{Pm_P(sa)}+C _Pm(sd)C _PJd(1)K _{P_A(1)}C _{j_P(sa)})K _Pa(V _PJa+θ _P-V _Pa-V _Pa(d))

+(C _Pm(sj)-C _Pm(j)-C _Pm(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _Pj[V _Pj+V _Pj(d)+C _Pj(a)K _Pa(V _PJa+θ _P-V _Pa-V _Pa(d))]

+(C _Pm(sj)-C _Pm(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _Aj[V _Aj+V _Aj(d)+C _Aj(a)K _Aa(V _AJa+θ _A-V _Aa-V _Aa(d))]

+(-C _{Pm_A(sa)}+C _Pm(sd)C _PJd(1)K _{P_A(1)}C _{j_A(sa)})K _Aa(V _AJa+θ _A-V _Aa-V _Aa(d))

+C _Pm(sd)C _PJd(1)K _{P_A(1)}(V _Pj+V _Pj(d))

(71)

$\begin{array}{c}{V}_{j\left(6\right)}=(I-C_{j\left(sd\right)}{C}_{PJD\left(1\right)}{K}_{P\_A\left(1\right)})\{{K_{sj}}^{-1}{K}_{Aj}\[V_{Aj}+V_{Aj\left(d\right)}+C_{Aj\left(a\right)}{K}_{Aa}(V_{AJa}+{\mathrm{\θ}}_A-V_{Aa}-V_{Aa\left(d\right)})\]\\ +{K_{sj}}^{-1}{K}_{Pj}\[V_{Pj}+V_{Pj\left(d\right)}+C_{Pj\left(a\right)}{K}_{Pa}(V_{PJa}+{\mathrm{\θ}}_P-V_{Pa}-V_{Pa\left(d\right)})\]\\ -C_{j\_A\left(sa\right)}{K}_{Aa}(V_{AJa}+{\mathrm{\θ}}_A-V_{Aa}-V_{Aa\left(d\right)})\\ -C_{j\_P\left(sa\right)}{K}_{Pa}(V_{PJa}+{\mathrm{\θ}}_P-V_{Pa}-V_{Pa\left(d\right)})\}\\ +C_{j\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}(V_{Pj}+V_{Pj\left(d\right)})\end{array}---\left(72\right)$

$\begin{array}{c}{V}_{Aa\left(6\right)}=V_{AJa}+{\mathrm{\θ}}_A+(-{K_{Asa}}^{-1}+C_{Aa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_A\left(sa\right)})K_{Aa}(V_{AJa}+{\mathrm{\θ}}_A-V_{Aa}-V_{Aa\left(d\right)})\\ +(-C_{Aa\_P\left(sa\right)}+C_{Aa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_P\left(sa\right)})K_{Pa}(V_{PJa}+{\mathrm{\θ}}_P-V_{Pa}-V_{Pa\left(d\right)})\\ -C_{Aa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1}{K}_{Aj}\[V_{Aj}+V_{Aj\left(d\right)}+C_{Aj\left(a\right)}{K}_{Aa}(V_{AJa}+{\mathrm{\θ}}_A-V_{Aa}-V_{Aa\left(d\right)})\]\\ -C_{Aa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1}{K}_{Pj}\[V_{Pj}+V_{Pj\left(d\right)}+C_{Pj\left(a\right)}{K}_{Pa}(V_{PJa}+{\mathrm{\θ}}_P-V_{Pa}-V_{Pa\left(d\right)})\]\\ +C_{Aa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}(V_{Pj}+V_{Pj\left(d\right)})\end{array}---\left(73\right)$

$\begin{array}{c}{V}_{Pa\left(6\right)}=V_{PJa}+{\mathrm{\θ}}_P+(-{K_{Psa}}^{-1}+C_{Pa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_P\left(sa\right)})K_{Pa}(V_{PJa}+{\mathrm{\θ}}_P-V_{Pa}-V_{Pa\left(d\right)})\\ +(-C_{Pa\_A\left(sa\right)}+C_{Pa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_A\left(sa\right)})K_{Aa}(V_{AJa}+{\mathrm{\θ}}_A-V_{Aa}-V_{Aa\left(d\right)})\\ -C_{Pa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1}{K}_{Aj}\[V_{Aj}+V_{Aj\left(d\right)}+C_{Aj\left(a\right)}{K}_{Aa}(V_{AJa}+{\mathrm{\θ}}_A-V_{Aa}-V_{Aa\left(d\right)})\]\\ -C_{Pa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1}{K}_{Pj}\[V_{Pj}+V_{Pj\left(d\right)}+C_{Pj\left(a\right)}{K}_{Pa}(V_{PJa}+{\mathrm{\θ}}_P-V_{Pa}-V_{Pa\left(d\right)})\]\\ +C_{Pa\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}(V_{Pj}+V_{Pj\left(d\right)})\end{array}---\left(74\right)$

V _Pd(6)＝V _{PJd_z}-K _sd ^-1C _PJd(1)K _{P_A(1)}K _sj ^-1K _Aj[V _Aj+V _Aj(d)+C _Aj(a)K _Aa(V _AJa+θ _A-V _Aa-V _Aa(d))]

-K _sd ^-1C _PJd(1)K _{P_A(1)}K _sj ^-1K _Pj[V _Pj+V _Pj(d)+C _Pj(a)K _Pa(V _PJa+θ _P-V _Pa-V _Pa(d))]

+K _sd ^-1C _PJd(1)K _{P_A(1)}C _{j_A(sa)}K _Aa(V _AJa+θ _A-V _Aa-V _Aa(d))

+K _sd ^-1C _PJd(1)K _{P_A(1)}C _{j_P(sa)}K _Pa(V _PJa+θ _P-V _Pa-V _Pa(d))

+K _sd ^-1C _PJd(1)K _{P_A(1)}(V _Pj+V _Pj(d))

(75)

2) compensation quantity optimization model modeling

Set up on station k, based on the sheet metal assembly deviation Optimized model of clamp compensation.Optimized variable chooses fixture extra anchor point normal direction compensation rate θ on station k _aand θ _p.Optimization aim is: when this station has been assembled, assembly parts A ^k+1the quadratic sum of the final Norma l deviation of each measuring point is minimum; And make the quadratic sum of each fixture extra anchor point normal direction compensation rate minimum.In conjunction with the sheet metal assembly deviation TRANSFER MODEL of the station k in assembling deviation MBM, if assembly parts A ^k+1middle A ^kmeasuring point have m, P ^kmeasuring point have n, then A ^k+1the final Norma l deviation V of each measuring point _{m (6)}can be expressed as:

V _m(6)＝[V _Am(6),V _Pm(6)] ^T＝[V _Am(6)1,V _Am(6)2,…,V _Am(6)m,V _Pm(6)1,V _Pm(6)2,…,V _Pm(6)n] ^T(76)

Wherein, V _{am (6) i}(i=1,2 ..., m) represent A ^kthe final Norma l deviation of m measuring point, V _{pm (6) j}(j=1,2 ..., n) represent P ^kthe final Norma l deviation of n measuring point.

If assembly parts A ^k+1middle A ^kextra anchor point have u, P ^kextra anchor point have v, then A ^k+1the normal direction compensation rate θ of each extra anchor point _kcan be expressed as:

θ _k＝[θ _A,θ _P] ^T＝[θ _A1,θ _A2,…,θ _Au,θ _P1,θ _P2,…,θ _Pv] ^T(77)

Wherein, θ _as(s=1,2 ..., u) represent A ^kthe normal direction compensation rate of the extra anchor point of u, θ _pt(t=1,2 ..., v) represent P ^kthe normal direction compensation rate of the extra anchor point of v.

If the objective function of this Optimized model is:

$f_1\left({\mathrm{\θ}}_k\right)=\underset{i=1}{\overset{m}{\Σ}}{\left(V_{Am\left(6\right)i}\right)}^2+\underset{j=1}{\overset{n}{\Σ}}{\left(V_{Pm\left(6\right)j}\right)}^2---\left(78\right)$

$f_2\left({\mathrm{\θ}}_k\right)=\underset{s=1}{\overset{u}{\Σ}}{\left({\mathrm{\θ}}_{As}\right)}^2+\underset{t=1}{\overset{v}{\Σ}}{\left({\mathrm{\θ}}_{Pt}\right)}^2---\left(79\right)$

The constraint condition that this Optimized model is considered is: after station k has assembled, assembly parts A ^k+1the final Norma l deviation V of each measuring point _{m (6)}within the deviation range that should allow in technological requirement; Further, according to the structural parameters feature of flexible jig, A ^k+1the compensation rate θ of the extra anchor point of each fixture _kshould within the adjustable scope of fixture anchor point.

If A ^k+1the maximum deviation V that each measuring point can occur within the scope of technological requirement _{m (6) _ max}for:

$\begin{array}{c}{V}_{m\left(6\right)\_\max }={\[V_{Am\left(6\right)\_\max },V_{Pm\left(6\right)\_\max }\]}^T\\ ={\[V_{Am\left(6\right)1\_\max },V_{Am\left(6\right)2\_\max },\mathrm{...},V_{Am\left(6\right)m\_\max },V_{Pm\left(6\right)1\_\max },V_{Pm\left(6\right)2\_\max },\mathrm{...},V_{Pm\left(6\right)n\_\max }\]}^T\end{array}---\left(80\right)$

If A ^k+1the compensation rate θ of the extra anchor point of each fixture _kadjustable extent comprise adjustable upper limit θ _{k_up}with adjustable lower limit θ _{k_low}, they are respectively:

$\begin{array}{c}{\mathrm{\θ}}_{k\_up}={\[{\mathrm{\θ}}_{A\_up},{\mathrm{\θ}}_{P\_up}\]}^T\\ ={\[{\mathrm{\θ}}_{A1\_up},{\mathrm{\θ}}_{A2\_up},\mathrm{...},{\mathrm{\θ}}_{Au\_up},{\mathrm{\θ}}_{P1\_up},{\mathrm{\θ}}_{P2\_up},\mathrm{...},{\mathrm{\θ}}_{Pv\_up}\]}^T\end{array}---\left(81\right)$

$\begin{array}{c}{\mathrm{\θ}}_{k\_low}={\[{\mathrm{\θ}}_{A\_low},{\mathrm{\θ}}_{P\_low}\]}^T\\ ={\[{\mathrm{\θ}}_{A1\_low},{\mathrm{\θ}}_{A2\_low},\mathrm{...},{\mathrm{\θ}}_{Au\_low},{\mathrm{\θ}}_{P1\_low},{\mathrm{\θ}}_{P2\_low},\mathrm{...},{\mathrm{\θ}}_{Pv\_low}\]}^T\end{array}---\left(82\right)$

This Optimized model is multiple-objection optimization, and its mathematical model can be expressed as:

minf ₁(θ _k)

minf ₂(θ _k)

$\begin{array}{c}\begin{array}{cc}s.t.& {\mathrm{\θ}}_k\∈G=\left\{{\mathrm{\θ}}_k\right|\left|V_{Am\left(6\right)i}\right|\≤V_{Am\left(6\right)i\_\max },\left|V_{Pm\left(6\right)j}\right|\≤V_{Pm\left(6\right)j\_max},\end{array}\\ i=1,2,\mathrm{...},m,j=1,2,\mathrm{...},n\}\end{array}---\left(83\right)$

θ _k∈H＝{θ _k|θ _{As_low}≤θ _As≤θ _{As_up},θ _{Pt_low}≤θ _Pt≤θ _{Pt_up},

s＝1,2,…,u,t＝1,2,…,v}

According in assembling deviation MBM, the station k of foundation considers fixture extra anchor point normal direction compensation rate θ _ksheet metal assembly deviation TRANSFER MODEL, can A be obtained ^k+1extra anchor point normal direction compensation rate θ _kwith the final Norma l deviation V of its measuring point _{m (6)}between relation, see formula (70) and formula (71).

At flexible assembly part A ^k+1in, subassembly A ^kassembling deviation on station (k-1) can be obtained by data acquisition module, comprises A ^kin the deviation of measuring point, fixture anchor point, station k assembly connection point position; Part P ^kmanufacture deviation, comprise P ^kin the deviation of measuring point, fixture anchor point, assembly connection point position, and the fixture deviations of station k is all contained in the input X of station k _k-1in, be known quantity.Further, in the assembling process of station k, when assembly technology does not change, each stiffness matrix and each linear system matrix remain unchanged.Therefore formula (70) and formula (71) can be expressed as:

V _Am(6)＝T _A+S _{A_A}θ _A+S _{A_P}θ _P(84)

V _Pm(6)＝T _P+S _{P_A}θ _A+S _{P_P}θ _P(85)

Wherein,

$\begin{array}{c}{T}_A=V_{Am}+V_{Am\left(d\right)}+(C_{Am\left(a\right)}-C_{Am\_A\left(sa\right)}+C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_A\left(sa\right)})K_{Aa}(V_{AJa}-V_{Aa}-V_{Aa\left(d\right)})\\ +(C_{Am\left(sj\right)}-C_{Am\left(j\right)}-C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Aj}{C}_{Aj\left(a\right)}{K}_{Aa}(V_{AJa}-V_{Aa}-V_{Aa\left(d\right)})\\ +(C_{Am\left(sj\right)}-C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Pj}{C}_{Pj\left(a\right)}{K}_{Pa}(V_{PJa}-V_{Pa}-V_{Pa\left(d\right)})\\ +(-C_{Am\_P\left(sa\right)}+C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_P\left(sa\right)})K_{Pa}(V_{PJa}-V_{Pa}-V_{Pa\left(d\right)})\\ +(C_{Am\left(sj\right)}-C_{Am\left(j\right)}-C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Aj}(V_{Aj}+V_{Aj\left(d\right)})\\ +\[(C_{Am\left(sj\right)}-C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Pj}+C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}\](V_{Pj}+V_{Pj\left(d\right)})\end{array}---\left(86\right)$

T _P＝V _Pm+V _Pm(d)+(C _Pm(a)-C _{Pm_P(sa)}+C _Pm(sd)C _PJd(1)K _{P_A(1)}C _{j_P(sa)})K _Pa(V _PJa-V _Pa-V _Pa(d))

+(C _Pm(sj)-C _Pm(j)-C _Pm(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _PjC _Pj(a)K _Pa(V _PJa-V _Pa-V _Pa(d))

+(C _Pm(sj)-C _Pm(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _AjC _Aj(a)K _Aa(V _AJa-V _Aa-V _Aa(d))

+(-C _{Pm_A(sa)}+C _Pm(sd)C _PJd(1)K _{P_A(1)}C _{j_A(sa)})K _Aa(V _AJa-V _Aa-V _Aa(d))

+[(C _Pm(sj)-C _Pm(j)-C _Pm(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _Pj+C _Pm(sd)C _PJd(1)K _{P_A(1)}](V _Pj+V _Pj(d))

+(C _Pm(sj)-C _Pm(sd)C _PJd(1)K _{P_A(1)}K _sj ^-1)K _Aj(V _Aj+V _Aj(d))

(87)

$\begin{array}{c}{S}_{A\_A}=\[C_{Am\left(a\right)}-C_{Am\_A\left(sa\right)}+C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_A\left(sa\right)}\\ +(C_{Am\left(sj\right)}-C_{Am\left(j\right)}-C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Aj}{C}_{Aj\left(a\right)}\]K_{Aa}\end{array}---\left(88\right)$

$\begin{array}{c}{S}_{A\_P}=\[C_{Am\left(sj\right)}-C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Pj}{C}_{Pj\left(a\right)}\\ -C_{Am\_P\left(sa\right)}+C_{Am\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_P\left(sa\right)}\]K_{Pa}\end{array}---\left(89\right)$

$\begin{array}{c}{S}_{P\_A}=\[(C_{Pm\left(sj\right)}-C_{Pm\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Aj}{C}_{Aj\left(a\right)}\\ -C_{Pm\_A\left(sa\right)}+C_{Pm\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_A\left(sa\right)}\]K_{Aa}\end{array}---\left(90\right)$

$\begin{array}{c}{S}_{P\_P}=\[C_{Pm\left(a\right)}-C_{Pm\_P\left(sa\right)}+C_{Pm\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{C}_{j\_P\left(sa\right)}\\ +(C_{Pm\left(sj\right)}-C_{Pm\left(j\right)}-C_{Pm\left(sd\right)}{C}_{PJd\left(1\right)}{K}_{P\_A\left(1\right)}{K_{sj}}^{-1})K_{Pj}{C}_{Pj\left(a\right)}\]K_{Pa}\end{array}---\left(91\right)$

If S _a=[S _{a_A}, S _{a_P}], S _p=[S _{p_A}, S _{p_P}], θ _k=[θ _a, θ _p] ^t, then formula (84) and formula (85) can be expressed as:

V _Am(6)＝T _A+S _Aθ _k(92)

V _Pm(6)＝T _P+S _Pθ _k(93)

Order $V_{m\left(6\right)}=\left[\begin{array}{c}{V}_{Am\left(6\right)}\\ V_{Pm\left(6\right)}\end{array}\right],T=\left[\begin{array}{c}{T}_A\\ T_P\end{array}\right],S=\left[\begin{array}{c}{S}_A\\ S_P\end{array}\right],$ Then have:

V _m(6)＝T+Sθ _k(94)

It can thus be appreciated that, in station k, assembly parts A ^k+1the Norma l deviation V of measuring point _{m (6)}with the normal direction compensation rate θ of the extra anchor point of fixture _klinear.According to the objective function of Optimized model, convolution (94), objective function f ₁(θ _k) can be expressed as again:

f ₁(θ _k)＝V _m(6) ^TV _m(6)＝(T+Sθ _k) ^T(T+Sθ _k)＝T ^TT+T ^TSθ _k+θ _k ^TS ^TT+θ _k ^T(S ^TS)θ _k(95)

Make T ^ts=A, S ^ts=B, then TS ^t=A ^t, formula (95) can turn to:

f ₁(θ _k)＝T ^TT+Aθ _k+θ _k ^TA ^T+θ _k ^TBθ _k(96)

Obviously, the capable full rank of S, has rand (S)=m+n, and S ^ts=B, therefore B is positive semidefinite symmetric matrix.Thus, the mathematical modulo pattern (83) of this Optimized model can be expressed as following form:

$\begin{array}{c}{\mathrm{minf}}_1\left({\mathrm{\θ}}_k\right)={{\mathrm{\θ}}_k}^T{\mathrm{B\θ}}_k+{\mathrm{A\θ}}_k+{{\mathrm{\θ}}_k}^T{A}^T+T^{T}T\\ {\mathrm{minf}}_2\left({\mathrm{\θ}}_k\right)={{\mathrm{\θ}}_k}^T{\mathrm{\θ}}_k\\ \begin{array}{ccc}s.t.& -V_{m\left(6\right)i\_\max }\≤S_i{\mathrm{\θ}}_k+T_i\≤V_{m\left(6\right)i\_\max }& i=1,2,\mathrm{...},m+n\end{array}\\ \begin{array}{cc}{\mathrm{\θ}}_{kj\_low}\≤I_j{\mathrm{\θ}}_k\≤{\mathrm{\θ}}_{kj\_up}& j=1,2,\mathrm{...},u+v\end{array}\end{array}---\left(97\right)$

Wherein, Ι is unit battle array, and S, T, A, B are real number matrix.Visible, this Optimized model is convex quadratic programming model.

3) optimal compensation amount solves

From formula (97), the Multi-objective Convex Quadratic Programming Solution problem being solved to inequality constrain of above-mentioned Optimized model.For this multi-objective optimization question, because the priority ranking of each optimization aim is had any different, that is: first optimization aim minf ₁(θ _k) priority ranking higher than second optimization aim minf ₂(θ _k), therefore hierarchical sequence method can be adopted to solve.First to most important objective function, then the layering of by-end function is optimized, the former when optimizing the latter, must be kept to change in allowed band.

The feasible zone D of this Optimized model is:

D＝{θ _k|-V _{m(6)i_max}≤S _iθ _k+T _i≤V _{m(6)i_max},θ _{kj_low}≤Ι _jθ _k≤θ _{kj_up}}

Wherein, i=1,2 ..., m+n, j=1,2 ..., u+v.

Because B is positive semidefinite symmetric matrix, so, for first optimization aim minf ₁(θ _k), its feasible zone non-NULL, and objective function has lower bound in feasible zone, then optimization problem has global minimizer, but may not be unique.And for second optimization aim minf ₂(θ _k), its feasible zone non-NULL, and objective function has lower bound in feasible zone, then optimization problem has global minimizer, and uniquely.

Constraint condition due to Optimized model is inequality constrain, can adopt the methods such as active set m ethod when solving each optimization aim.First first optimization aim minf is solved ₁(θ _k), due to the restriction of constraint condition, may there is the situation without feasible solution in the optimum solution in feasible zone D, at this moment only by the method for the normal direction compensation rate of alignment jig anchor point, cannot meet technological requirement, need by additive method; As first optimization aim minf ₁(θ _k) when feasible zone D has feasible solution, if unique solution, be the optimum solution of the Optimized model that formula (97) represents, if be not unique solution, then, in its optimum solution set territory, solve second optimization aim minf ₂(θ _k) optimal value, namely first aim function is converted into auxiliary constraint, to obtain optimum solution.

3. compensate and implement

According in compensation scheme decision-making module, to the solving result of the assembling deviation Optimized model based on clamp compensation, perform associative operation.If there is feasible solution, then according to these group data, regulate the normal direction compensation rate of extra fixture anchor point in station k.If there is not feasible solution, illustrate and regulate the extra anchor point of fixture of this station cannot meet the requirement of joining deviation quality, then need to consider to adopt other modes to ensure assembly quality, as: adopt the holder locator that adjustable extent is larger, add new fixture anchor point etc. at this station, the concrete scheme of this part content is not within the scope of the invention.

Claims (5)

1. the sheet metal assembly dimensional discrepancy control method compensated based on multistation assembling jig, it is characterized in that: first, in flexible piece multistation assembling process, by prediction, the compensation assembling deviation of station, and the fixture locating point position of participation clamp compensation can normal direction be regulated within the specific limits; Secondly, in control theory based on state-space method, in the location or reorientation link of the assembling of flexible piece multistation, add clamp compensation system carry out deviation data collection, compensation scheme decision-making and compensate implementing, to reduce the assembling deviation on the subsequent work stations that is about to carry out assembling.

2. method according to claim 1, is characterized in that described clamp compensation system comprises deviation data acquisition module, compensation scheme decision-making module and compensates and implements module.

3. method according to claim 2, is characterized in that described deviation data acquisition module is the importation of clamp compensation system; Due to the input quantity of whole assembly system, the manufacture deviation namely participating in all parts assembled is known quantity, and comprise the input of the clamp compensation system of first station, therefore first station does not perform this module; For other station except first station, deviation data collection refers to the dimensional discrepancy value gathering and be about to carry out subassembly that assemble, that assembled by preposition station in subsequent work stations; Using in the critical product feature (KPC) of subassembly and subsequent work stations, its fixture locating point position, assembly connection point position are as deviation data collection point, and the mode of image data comprises: being derived by the assembling deviation TRANSFER MODEL of preposition station draws and obtained by survey instrument measurement.

4. method according to claim 2, is characterized in that described compensation scheme decision-making module is the core of clamp compensation system, comprises assembling deviation modeling, compensation quantity optimization model modeling and optimal compensation amount and solves three steps, wherein:

(1) assembling deviation modeling refers to: using the normal direction compensation rate of fixture anchor point as one group of regulated variable, sets up the sheet metal assembly deviation TRANSFER MODEL of subsequent work stations;

For first station, the deviation source of consideration is the part manufacture deviation and the fixture deviations that participate in assembling; For other station except first station, the deviation source of consideration comprises the subassembly assembling deviation, part manufacture deviation and the fixture deviations that participate in assembling;

Modeling process comprises location, clamping, connection, release resilience four steps, take small deformation, linear elasticity to suppose to flexible piece, use influence coefficient method, limited element analysis technique, super first stiffness matrix theory sets up fixture anchor point normal direction compensation rate, deviation transitive relation between deviation source deviation and the measuring point deviation of these station assembly parts;

(2) compensation quantity optimization model modeling refers to: set up the assembling deviation Optimized model of this station based on clamp compensation; Optimized variable is the normal direction compensation rate of the adjustable anchor point of fixture; Optimization aim comprises: make the quadratic sum of each measuring point deviation of these station assembly parts minimum, makes the quadratic sum of the compensation rate of each adjustable anchor point of fixture minimum; Constraint condition comprises: the normal direction compensation rate of each fixture anchor point is within certain adjustable extent, and each measuring point deviation of assembly parts requires within the scope of permission at assembly technology;

(3) optimal compensation amount solves and refers to: aforementioned built solving of compensation quantity optimization model is converted into quadratic programming problem; This quadratic programming has multiple optimization aim, and constraint condition is inequality; Adopt hierarchical sequence method to solve, in the scope that constraint condition specifies, draw the optimum solution meeting optimization aim; And discuss with or without feasible solution, if there is no feasible solution, then only adopt the mode of alignment jig anchor point cannot meet the assembling quality requirement of this station, need to consider other method.

5. method according to claim 2, is characterized in that the execution part that module is clamp compensation system is implemented in described compensation; For according in compensation scheme decision-making module to the solving result of optimal compensation amount, adjustment fixture anchor point.