# Device of machine tool framework sets method delibrate beforehand from actor

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- source:BAGANZ CNC Machining

1 experiment designs a method to reach those who answer similar model to build experiment to devise a method is to use research to design parameter to devise the strategy of a kind of sampling that the state affects to the model. Experimental design is compose establishs the important link in similar model process, a number that decided place of tectonic and similar model needs example to nod and the space of these dots distributing circumstance. The center is used in article complex design method (CCDs) undertakes the experiment is designed, this method was put forward the earliest 1951 by Box and Wilson. Because this kind designs a method to have orderly native place gender, forecast efficiency more advanced characteristic, already got applied extensively in be designed actually. Use a center complex design method is offerring less experimental time to fall, mature experiment designs the mutual effect impact between variable. Similar model adopts the method of several manage statistic and experimental design, in the design variable is mixed answer between establish relationship of a kind of function, use approximate and complex real problem. Commonly used similar model has multinomial to answer model of function of curved surface, radial radical, Kriging model to wait. Answering cover magic art is to be used at handling much more variable problem to construct the processing technique of a statistic of model and analysis, data set incline to can be decided in inaccuracy at why be being planted when the curve, plan to close to what whole data set undertakes whole, can solve what at the same time in many designs variable action plays an end to optimize a problem well. Because the choice in this article is built,answer similar model to undertake optimizing begging solving. 1.

2 optimize flow to optimize flow, design variable and its change space certainly according to real problem above all, use a center complex design method undertakes the experiment is designed, according to the experiment the design undertakes example dot collects; to be opposite next as a result gather of each groups of example undertakes finite yuan of analysis, get structural response. Through planning to add up to design variable and system to answer the function between the relation is built 2 rank answer curved surface, answering aspirant travel to search actor to seek solution. Pass free and random law, optimize the mathematical model of the problem according to built much goal, in whole 2 rank answer curved surface to go up preliminary seek optimum solution, the optimum solution that seeks with free and random law again is new example space, use genetic algorithm to relapse iteration seeks solution, undertake finding actor further, test and verify is best the true value of solution. If satisfy precision requirement, optimize end of the process that seek solution, if be not satisfied,amend answer curved surface farther iteration seeks solution. The precision that answers curved surface affects the actor of low quality of the result directly, the error value of the similar model that the requirement in article drafts to close is in 1% less than. 1.

What the of processing technique that 3 much targets optimize a problem often encounters in optimizing a design is much target optimizes a problem. To the processing technique that much target optimizes, basically have an opinion function law, statified seek way of program of solution, target. Have the aid of of evaluation function law is tectonic some kind of proper evaluation function, translate into of much target problem simple goal issue seeks solution. Eclectic law is a kind of processing technique that evaluates function, its basic idea is an architect one of choosing much target undertakes optimizing as target function, and it is OK to look other target function look other target function the tie of flexible, set a value that do not hope to exceed or is less than, have problem of simple goal of translate into of much target problem optimizing. Eclectic method is used in article to the bed (situation of imports and exports of Chinese machine tool) body structure undertakes optimizing designing, optimize a model to be: Maxk(1)s.

T.

Xui(i=1 of ≤ of Xi of ≤ of Xli of F-[f][f] ≤ ε , 2, ... , in type of of N) : ε -- the change that allows lathe bed fundamental frequency in optimizing a process measures;k -- ;[f] of machine tool stiffness -- the fundamental frequency;f of structure of former lathe bed -- the fundamental frequency;Xi of structure of the lathe bed after optimizing -- design variable;Xui, xli -- the design is restricted variably up and down. Type (1) makes clear seek design variable Xi(i=1, 2, ... , the optimal value of N) , below the tie condition that makes the structure is close to original structure in fundamental frequency, structural stiffness is the biggest. 1.

4 optimizing genetic algorithm of algorithmic is one kind draws lessons from biology extent nature to choose to develop the height that rise with evolution collateral, random, get used to search algorithm oneself. It used a group to search a technology, will plant group of delegates solution of a group of problems, plant currently through be opposite group bring to bear on a series of genetic operations such as choice, across and mutation, produce new generation kind group, make plant stage by stage group of evolution to the state that includes approximate and optimum solution. The combination that uses genetic algorithm to beg solution to optimize a model to be able to solve aleatoric dimension function optimizes a problem, can find the overall situation in answering a face optimum solution, at the same time genetic algorithm can solve the problem of disperse variable well. Genetic algorithm demands solution technological process. 2 calculate of exemple 2.

Lathe bed of cylindrical grinder of some model of of of 1 research target is cast by casting pig and become. Lathe bed grows 2900mm, wide 1170mm, tall 707mm, mural thick 15mm.

Before there is V- to make the same score on lathe bed model slideway, 2800mm of slideway overall length, lathe bed interior has 8 horizontal clapboard and a level before transverse muscle board. Lathe bed has 2 horizontal strokes, mediastinum board respectively after. The horizontal clapboard ply of lathe bed interior is 15mm, lathe bed underside fills up iron to prop up by 11. Many arenaceous aperture were installed on former lathe bed, finite yuan of stiffness that analyses a result to show structure of former lathe bed for 1.

64 × 105N/mm, fundamental frequency is 212.

8Hz.

To undertake optimizing designing, an arenaceous Kong Quan of lathe bed interior the ministry is filled on, design initiative model to undertake to its finite yuan of analysis, lathe bed stiffness is 1.

68 × 105N/mm, fundamental frequency is 214Hz. 2.

The span of horizontal clapboard of interior of lathe bed of of of 2 designs variable (X1, x2, x3, x4) , the ply X5 of horizontal clapboard and the span that fill up iron (X6, x7, x8) is design variable, study they are right the influence of function of lathe bed structure, the design is variable. 2.

3 optimize of the that seek solution to use what what show to optimize a process to undertake optimizing begging solving, each design a space variably. Use a center the example point that complex design method makes 81 groups of experiments design needs design variable, use finite yuan of law analysis variable of every groups of designs and fundamental frequency, stiffness answers the concern between. Least square method of have the aid of, according to the result that the experiment designs, construct respectively between fundamental frequency and stiffness and design variable 2 rank answer curved surface, difference of two the biggest opposite damage that answer curved surface distributing for 0.

61% with 0.

74% , accordingly similar model satisfies the requirement of precision, can replace actual model to undertake optimizing begging solving. Use eclectic method according to type (1) undertakes much target optimizes problem processing, use genetic algorithm to undertake begging solving to optimizing a problem. The design space design that designs variable is variable / Mm takes value scope / Mm initiative value / 4002502400 ～ of Mmx1200 ～ 11009504200 ～ of 600575x3700 ～ 9008708200 ～ of ～ of 1200873x7700 of ～ of 400250512 ～ 1515x6700 of of 900500 2.

The 4 results after optimizing result , stiffness by 1 original.

68 × 105N/mm increases to 1.

73 × 105N/mm, rose 3.

04% , fundamental frequency is reduced by original 214Hz 212.

8Hz, reduced 0.

56% .

Optimize performance of condition of activity of construction of around lathe bed to design variable quite / the stiffness after before Mm is optimized, be being optimized / (N/mm) fundamental frequency / 3 develop of of of of of the X1250345x2575441x15x500213 after before after before Hz is optimized, be being optimized, be being optimized, be being optimized attack optimize structure of lathe bed to need to leave in logical place go out, go to the lavatory on one hand cast a process piece arenaceous, also can reduce lathe bed quality on the other hand. The seat that gives arenaceous opening must assure to be after starting a hole, structural stiffness and fundamental frequency satisfy the design requirement of lathe bed. Structural develop attacks optimize can be in given reasonable material is formed to distributing in dimensional structure. Density law is used to undertake optimizing designing to lathe bed structure in article, in order to get a reasonable arenaceous aperture seat. The density that introduced a kind of hypothesis artificially is alterable material, every unit bogus density is design variable, attack structural develop optimize material of problem translate into problem of best distributinging design, application optimizes standard standard to seek solution material is best distributing. Develop attacks optimize mathematical model to be: MaxK(2)s.

In type of Mlimit of ≤ of 1M of ≤ of T0< β I: K -- I of stiffness; β -- the bogus density;M of unit I -- the structure attacks the quality;Mlmit after optimizing -- the after optimizing tractor dry mass of set. Quality of the lathe bed after set is optimized drops 10% , apply density law to undertake to lathe bed structure develop attacks optimize, the develop after optimizing attacks. Gray represents the place that lathe bed material can delete, but gray data shows merely theoretic can delete, whether to delete the place material to need to combine the real need of lathe bed structure after all. If although can be deleted,square of ground of lathe bed gasoline tank expects, but cannot delete through starting a hole, can choose to reduce the method with large wall, achieve the goal that reduces quality. And a few structures attack through develop the graph shows material wants to withhold, but structure of actual lathe bed needs a few opening, can delete a few material to satisfy real requirement appropriately only. Develop of structure of combinative lathe bed attacks the real need of graph and lathe bed structure, in lathe bed interior horizontal horizontal clapboard and lathe bed underside leave give a proper arenaceous opening, reduce wall of lathe bed underside thick, the structure after lathe bed structure deletes material is shown like 6. Finite to optimizing the structure after to undertake yuan of analysis, function of structure of the lathe bed after optimizing. The stiffness of lathe bed structure is 1.

74 × 105N/mm, the stiffness value that compares structure of former lathe bed became great 1 × 104N/mm, increased 5.

8% .

Although fundamental frequency is 204.

5Hz, the fundamental frequency that compares structure of former lathe bed drops 7.

3Hz, but quality of whole lathe bed by 1496 original.

6kg falls 1424.

3kg was reduced 4.

83% .

Develop attacks optimize function of structure of around lathe bed to compare stiffness of lathe bed structure / (N/mm) fundamental frequency / Hz quality / before Kg is optimized 1.

64 × 105212.

81496.

6 after optimizing 1.

74 × 105205.

51424.

3 change are measured 5.

8%(+)3.

43%(-)4.

83%(+) notes: + state ascendant;- expresses to drop of 4 epilogue uses experimental design and similar model method are span of horizontal to lathe bed interior clapboard, horizontal the ply of clapboard, position that fill up iron undertook optimizing designing. After deciding horizontal clapboard span and mat iron position and horizontal clapboard ply, use density law to undertake to lathe bed structure develop attacks optimize a design, fixed a logical arenaceous aperture place. Consider to make clear: Such mechanical function that optimizes strategy to be able to raise lathe bed effectively not only, and have taller design efficiency. Was a means that offers to place to undertake test and verify with lathe bed of some model grinder. Stiffness of structure of the lathe bed after optimizing increased 5.

8% , lathe bed quality was reduced 4.

83% . CNC Milling