CN102193521B - Multi-hole parallel processing method based on genetic algorithm - Google Patents

Abstract

The invention discloses a multi-hole parallel processing method based on a genetic algorithm. Multi-hole processing is carried out on a reconfigurable and parallel drilling numerical control machine tool as an application object. The method comprises the following concrete steps of: 1, confirming Z-direction movement speeds Vw and Vt of a workpiece and a right cutter installed on a workbench of the reconfigurable and parallel drilling numerical control machine tool; 2, confirming related technological parameters of each hole to be processed on a processing surface of the workpiece and the workpiece; 3, establishing a technological optimization objective and constrained conditions which comprises the hole processing time, a cutter feeding speed, rotating speed constraint, and cutter life constraint; 4, solving with a genetic algorithm to obtain a chromosome with a minimum moderate value; and 5, carrying out numerical control code compilation on processing of part holes according to the structure of the chromosome with the minimum moderate value and finally beginning to process. By adopting the method, the processing parameters of the hole can be quickly obtained, a processing route of the hole can be quickly generated, and a processing simulation process of the cutter related to the time can be quickly generated.

Description

Multi-hole parallel processing method based on genetic algorithm

Technical field

The invention belongs to Reconfigurable Manufacturing System production control technical field, be used for restructural drilling machine control technology in parallel, be specifically related to a kind of multi-hole parallel processing method based on genetic algorithm.

Background technology

Reconfigurable Manufacturing System can effectively solve the production efficiency of existing manufacturing system existence and the contradiction between the flexibility, takes full advantage of the contradiction between existing resource and the new processing request of adaptation.Greatly shorten the Time To Market of planning, design and construction time and the new product of the manufacturing system of product variety and change of production, significantly investment, the market competitiveness that reduces production costs, ensures the quality of products, makes rational use of resources, improves enterprise and the profitability of compressibility construction.

The restructural parallel machine has following characteristic as the important composition module of reconfigurable system: working (machining) efficiency is high, and cost is low, and is flexible high.In recent years, existing multiple theoretical method is realized the structural design of Reconfigurable Machine Tools.As: professor Li Aiping of Tongji University proposes method for designing (Machine Design and research, 2010,26 (5): P114-P118) of the Reconfigurable Machine Tools of character-driven; Professor Wang Youjun of Northwestern Polytechnical University has carried out design studies to the parts of restructural deep hole working machine, has solved a difficult problem (machine science and technology, 2009,28 (12): P1572-P1575) of configurable component design in the reconfigurable design; East China University of Science's Wang Qing penetrating judgment is awarded according to concurrent engineering theoretical, has proposed a kind of based on process planning and parallel Reconfigurable Machine Tool Design method (China Mechanical Engineering, 2005,16 (7): P588-P593) of finishing of lathe configuration.Above-mentioned achievement in research provides important evidence to the Physical Reconstruction (being hardware reconstruct) of Reconfigurable Manufacturing System.

Yet, at present relatively less to the research of soft reconstruct theory in the Reconfigurable Manufacturing System, especially the restructural parallel machine is carried out product processing technique optimization just still less.Existing achievement in research has provided a technological design general frame structure and thinking mostly, and specific aim is not strong, and Process Planning is complicated, and technological parameter is difficult to determine, design proposal be feasible solution be not optimum solution.And because the motion process of restructural parallel machine is complicated, the variation of its technological design requires to have the flexibility of height and optimization ability fast.Therefore, existing multi-hole parallel Design Processing and optimization method require further improvement.

Summary of the invention

The purpose of this invention is to provide a kind of multi-hole parallel processing method based on genetic algorithm, it is not enough to have solved two aspects that exist in the prior art: under multiple processing constraint condition, and the fast automatic difficulty of choosing of hole working process parameter; Process route is difficult to find optimum during porous processing, especially adds man-hour at multi-hole parallel, can only determine by means of artificial experience or according to simple rule, causes working (machining) efficiency low.

The technical solution adopted in the present invention is, a kind of multi-hole parallel processing method based on genetic algorithm, carry out porous processing as application take restructural drilling numerically-controlled machine in parallel, left cutter only has the degree of freedom of X-axis traverse feed, the degree of freedom that right cutter has X-axis laterally and Z axis vertically moves, platen moves and can rotate around Z axis along Z axis, and the method is specifically implemented according to following steps

Step 1: determine to be installed in workpiece on the restructural drilling numerically controlled machine in parallel and the Z-direction translational speed V of right cutter _w, V _t

Step 2: determine that each intends the related process parameter of machining hole on workpiece and the machined surface thereof, the related process parameter comprises following several:

BHN-part material hardness, unit is HB,

The diameter in d-hole, unit are mm,

n _AThe number in hole on the-A face,

f _AjThe speed of feed in j hole the on-processing A face, j=1,2 .., n _A, unit is mm/rev,

n _BThe number in hole on the-B face,

f _BtThe speed of feed in t hole the on-processing B face, t=1,2 .., n _B, unit is mm/rev,

h _AjThe degree of depth in j hole the on-processing A face, unit is mm,

h _BtThe degree of depth in t hole the on-processing B face, unit is mm,

N _AjThe cutter rotating speed in j hole the on-processing A face, unit is rpm,

N _BtThe cutter rotating speed in t hole the on-processing B face, unit is rpm,

O _AjThe Z-direction coordinate figure in j hole the on-face A, unit are mm,

O _BtThe Z-direction coordinate figure in t hole the on-face B, unit are mm;

Step 3: set up process optimization target and constraint condition

3.1) objective function is that the hole is the shortest process time: F=Min{max (T ₁, T ₂),

Wherein, T ₁Be the deadline of left cutter: ${\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="HDA0000063030950000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1=\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}[t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}],$

T ₂Be the deadline of right cutter: $T_2=\underset{t=1}{\overset{n_B}{\mathrm{\&Sigma;}}}[t_{\mathrm{Bt}}+t_{\mathrm{Btm}}+t_{\mathrm{Btw}}],$

t _AjBe the drilling time in hole: $t_{\mathrm{Aj}}=\frac{h_{\mathrm{Aj}}}{f_{\mathrm{Aj}}{N}_{\mathrm{Aj}}},$ j＝1，2，...，n _A，

t _BtBe the drilling time in hole: $t_{\mathrm{Bt}}=\frac{h_{\mathrm{Bt}}}{f_{\mathrm{Bt}}{N}_{\mathrm{Bt}}},$ t＝1，2，...，n _B，

t _AjmBe the part traveling time: $t_{\mathrm{Ajm}}=\frac{|O_{A(j+1)}-O_{\mathrm{Aj}}|}{V_w},$ j＝1，2，...，n _A-1，

t _BtmTraveling time for right cutter:

$t_{\mathrm{Btm}}=\frac{(O_{A(j+1)}-O_{\mathrm{Aj}})+(O_{B(t+1)}-O_{\mathrm{Bt}})}{V_t},$

In the above-mentioned formula, t _Ajw, t _BtwBe respectively the processing stand-by period of left cutter, right cutter, this time determines according to machining state in optimizing process,

3.2) constraint condition:

3.21) left cutter, right tool feeding speed and rotating speed constraint comprise:

f _Amin＜f _Aj≤f _Amax，j＝1，2，...，n _A，

f _Bmin＜f _Bt≤f _Bmax，t＝1，2，...，n _B，

N _Amin＜N _Aj≤N _Amax，j＝1，2，...，n _A，

N _Bmin＜N _Bt≤N _Bmax，t＝1，2，...，n _B，

In the above-mentioned formula, f _Min, f _MaxBe respectively minimum and the maximal value of left cutter, right tool feeding speed; N _Min, N _MaxBe respectively minimum and the maximal value of left cutter, right cutter rotating speed;

3.22) the life-span constraint of left cutter, right cutter

$24000=\frac{\mathrm{\&pi;d}}{12}{{\mathrm{NT}}_L}^{0.15}{f}^{0.6}{d}^{0.3}\&times;{\left(\mathrm{BHN}\right)}^{1.25},$

In the above-mentioned formula, T _LBe cutter life, unit minute is convenient to optimize and calculates, and adapts to the multi-state condition of work, and the cutter life constraint is converted into following form:

$\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}\frac{t_{\mathrm{Aj}}}{T_{\mathrm{LAj}}}=\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Aj}}^{5.67}{\mathrm{<figure-callout\; id="3"\; label="f\; Aj"\; filenames="HDA0000063030950000011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{\mathrm{Aj}}^{}\&times;\frac{h_{\mathrm{Aj}}{d}_{\mathrm{Aj}}^{0.667}\&times;{\left(\mathrm{BHN}\right)}^{8.33}}{1.26\&times;{10}^{33}}\&le;1,$

$\underset{t=1}{\overset{n_B}{\mathrm{\&Sigma;}}}\frac{t_{\mathrm{Bt}}}{T_{\mathrm{LBt}}}=\underset{j=1}{\overset{n_B}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Bt}}^{5.67}{\mathrm{<figure-callout\; id="3"\; label="f\; Bt"\; filenames="HDA0000063030950000011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{\mathrm{Bt}}^{}\&times;\frac{h_{\mathrm{Bt}}{d}_{\mathrm{Bt}}^{0.667}\&times;{\left(\mathrm{BHN}\right)}^{8.33}}{1.26\&times;{10}^{33}}\&le;1,$

Wherein, T _LAjBe the cutter life of cutter under the operating mode in j hole of A face processing;

T _LBtBe the cutter life of cutter under the operating mode in t hole of B face processing;

d _AjDiameter for j hole on the A face;

d _BtDiameter for t hole on the B face;

Step 4: genetic algorithm for solving

4.1) genetic coding

Chromosome is divided into two sections of A, B represents respectively A, B face, each gene on the chromosome represents machining hole, has comprised the related process parameter in hole, and the order of gene represents the processing sequence in hole;

4.2) the initial population generation

Certain hole of choosing at random on the A face is placed on the chromosomal A section, and is satisfying under speed of feed and the rotating speed constraint condition technological parameter that generates the hole, repetitive operation until the hole on the A face all be put on the A section chromosome;

Same method generates B section chromosome, and determines chromosomal related process parameter, repeats aforesaid operations and produces new item chromosome, until chromosome number reaches colony's number;

4.3) appropriate function calculation

Calculate every chromosomal appropriateness value in the colony according to optimization aim, computing method are as described in the step 3, and this moment, key issue was to determine the stand-by period of tool sharpening, the concrete following several situation that is divided into of calculating:

Situation 1, when $t_{\mathrm{Aj}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ l _B∈ [1, n _B] time,

If a. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ So $t_{\mathrm{Btw}}=(t_{\mathrm{Aj}}+t_{\mathrm{Ajm}})-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$

If b. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ So left cutter, right cutter stand-by period are 0,

Situation 2, when $t_{\mathrm{Aj}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ l _B∈[1，n _B]，

The stand-by period of left cutter is: $t_{\mathrm{Ajw}}=t_{\mathrm{Aj}}-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$

If c. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ So $t_{\mathrm{Btw}}=t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$

If d. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ The stand-by period of so right cutter is t _Btw=0,

4.4) carry out genetic manipulation

Produce new colony by the simulation genetic process,

A. replicate run

Choose the chromosome of appropriate functional value minimum in the current colony and put into new colony;

B. interlace operation

According to probability P _cIntersect, choose at random two chromosomes in the current colony, the A in the chiasmatypy, B section produce two new chromosomes and put into new colony;

C. mutation operation

According to probability P _mMake a variation, choose at random the item chromosome in the current colony, extract the regeneration that any one gene carries out technological parameter in A, B section respectively, newly-generated chromosome is put into new colony;

D. supply colony

Use the initialized method of colony to generate new chromosome, supply colony's chromosome number;

4.5) the algorithm end

If reach the iterations of algorithm then stop computing, the minimum chromosome of output appropriateness value, otherwise the operation of repeating step 4.3-step 4.4;

Step 5: the chromosome structure of the appropriateness value minimum that obtains according to step 4, the numerical control code establishment is carried out in the processing of hole in piece part, determine speed of feed, cutter rotating speed, cutter radius compensation, translational speed and the cutting line of left and right sides cutter in the NC Machining Process, the numerical control code establishment standard of combining with digital control lathe, finish the establishment of numerical control code, the simulation feed tries processing and formal processing at last.

Beneficial effect of the present invention is: under the conditions such as geometric parameter that satisfy machine tooling operating mode, cutter life constraint and hole, use algorithm can obtain rapidly the machined parameters in hole; On the basis that technological parameter is determined, the shortest in target to realize process time, the processing route in generation hole; According to the structural constraint of lathe, generate the processing simulation process of cutter and time correlation.

Description of drawings

Fig. 1 is the mounting structure synoptic diagram of the inventive method cutter and workpiece;

Fig. 2 is the principle schematic of calculating the cutter stand-by period in the inventive method, wherein a is the stand-by period of the tool sharpening in the first situation, b is the stand-by period of the tool sharpening in the second situation, c is the stand-by period of the tool sharpening in the third situation, and d is the stand-by period of the 4th kind of tool sharpening in the situation;

Fig. 3 is the appropriate function trend of evolution figure of employing scheme 1 in the inventive method;

Fig. 4 is the appropriate function trend of evolution figure of employing scheme 2 in the inventive method.

Among the figure, 1. left cutter, 2. right cutter, 3. workpiece.

Embodiment

The present invention is described in detail below in conjunction with the drawings and specific embodiments.

Method of the present invention is carried out porous processing as application take restructural drilling numerically-controlled machine in parallel, specifically implements according to following steps:

Step 1: with reference to Fig. 1,1 on left cutter has the laterally degree of freedom of (X-direction) feeding, right cutter 2 has laterally mobile degree of freedom of (X-direction) vertical (Z-direction), worktable moves and can rotate around Z axis along Z axis, in the case, determine respectively to be installed in workpiece 3 on the restructural drilling numerically controlled machine in parallel and the Z-direction translational speed V of right cutter 2 _w, V _t

Step 2: determine that each intends the related process parameter of machining hole on workpiece and the machined surface thereof, the structure of workpiece 3 as shown in Figure 1, A face hole A1, A2.... hole, the hole An that need to process for example, the hole B1 that the B face need to be processed, B2.... hole, hole Bn, the related process parameter comprises following several:

BHN-part material hardness, unit is HB,

The diameter in d-hole, unit are mm,

n _AThe number in hole on the-A face,

f _AjThe speed of feed in j hole the on-processing A face, j=1,2 ..., n _A, unit is mm/rev,

n _BThe number in hole on the-B face,

f _BtThe speed of feed in t hole the on-processing B face, t=1,2 ..., n _B, unit is mm/rev,

h _AjThe degree of depth in j hole the on-processing A face, unit is mm,

h _BtThe degree of depth in t hole the on-processing B face, unit is mm,

N _AjThe cutter rotating speed in j hole the on-processing A face, unit is rpm,

N _BtThe cutter rotating speed in t hole the on-processing B face, unit is rpm,

O _AjThe Z-direction coordinate figure in j hole the on-face A, unit are mm,

O _BtThe Z-direction coordinate figure in t hole the on-face B, unit are mm;

Step 3: set up process optimization target and constraint condition

3.1) objective function is that the hole is the shortest process time: F=Min{max (T ₁, T ₂),

Wherein, T ₁Be the deadline of left cutter 1: ${\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="HDA0000063030950000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1=\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}[t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}],$

T ₂Be the deadline of right cutter 2: $T_2=\underset{t=1}{\overset{n_B}{\mathrm{\&Sigma;}}}[t_{\mathrm{Bt}}+t_{\mathrm{Btm}}+t_{\mathrm{Btw}}],$

t _AjBe the drilling time in hole: $t_{\mathrm{Aj}}=\frac{h_{\mathrm{Aj}}}{f_{\mathrm{Aj}}{N}_{\mathrm{Aj}}},$ j＝1，2，...，n _A，

t _BtBe the drilling time in hole: $t_{\mathrm{Bt}}=\frac{h_{\mathrm{Bt}}}{f_{\mathrm{Bt}}{N}_{\mathrm{Bt}}},$ t＝1，2，...，n _B，

t _AjmBe the part traveling time: $t_{\mathrm{Ajm}}=\frac{|O_{A(j+1)}-O_{\mathrm{Aj}}|}{V_w},$ j＝1，2，...，n _A-1，

t _BtmTraveling time for right cutter 2: $t_{\mathrm{Btm}}=\frac{(O_{A(j+1)}-O_{\mathrm{Aj}})+(O_{B(t+1)}-O_{\mathrm{Bt}})}{V_t},$

In the above-mentioned formula, t _Ajw, t _BtwBe respectively the processing stand-by period of left cutter 1, right cutter 2, this time determines according to machining state in optimizing process,

3.2) constraint condition:

3.21) constraint of left and right sides tool feeding speed and rotating speed comprises:

f _Amin＜f _Aj≤f _Amax，j＝1，2，...，n _A，

f _Bmin＜f _Bt≤f _Bmax，t＝1，2，...，n _B，

N _Amin＜N _Aj≤N _Amax，j＝1，2，...，n _A，

N _Bmin＜N _Bt≤N _Bmax，t＝1，2，...，n _B，

In the above-mentioned formula, f _Min, f _MaxBe respectively minimum and the maximal value of left and right sides tool feeding speed; N _Min, N _MaxBe respectively minimum and the maximal value of left and right sides cutter rotating speed;

3.22) constraint of left and right sides cutter life

$24000=\frac{\mathrm{\&pi;d}}{12}{{\mathrm{NT}}_L}^{0.15}{f}^{0.6}{d}^{0.3}\&times;{\left(\mathrm{BHN}\right)}^{1.25},$

In the above-mentioned formula, T _LBe cutter life, unit minute is convenient to optimize and calculates, and adapts to the multi-state condition of work, and the cutter life constraint is converted into following form:

$\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}\frac{t_{\mathrm{Aj}}}{T_{\mathrm{LAj}}}=\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Aj}}^{5.67}{\mathrm{<figure-callout\; id="3"\; label="f\; Aj"\; filenames="HDA0000063030950000011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{\mathrm{Aj}}^{}\&times;\frac{h_{\mathrm{Aj}}{d}_{\mathrm{Aj}}^{0.667}\&times;{\left(\mathrm{BHN}\right)}^{8.33}}{1.26\&times;{10}^{33}}\&le;1,$

$\underset{t=1}{\overset{n_B}{\mathrm{\&Sigma;}}}\frac{t_{\mathrm{Bt}}}{T_{\mathrm{LBt}}}=\underset{j=1}{\overset{n_B}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Bt}}^{5.67}{\mathrm{<figure-callout\; id="3"\; label="f\; Bt"\; filenames="HDA0000063030950000011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{\mathrm{Bt}}^{}\&times;\frac{h_{\mathrm{Bt}}{d}_{\mathrm{Bt}}^{0.667}\&times;{\left(\mathrm{BHN}\right)}^{8.33}}{1.26\&times;{10}^{33}}\&le;1,$

Wherein, T _LAjBe the cutter life of cutter under the operating mode in j hole of A face processing;

T _LBtBe the cutter life of cutter under the operating mode in t hole of B face processing;

d _AjDiameter for j hole on the A face;

d _BtDiameter for t hole on the B face;

Step 4: genetic algorithm for solving

4.1) genetic coding

Chromosome is divided into two sections of A, B represents respectively A, B face, each gene on the chromosome represents machining hole, has comprised the related process parameter in hole, and the order of gene represents the processing sequence in hole;

4.2) the initial population generation

Certain hole of choosing at random on the A face is placed on the chromosomal A section, and is satisfying under speed of feed and the rotating speed constraint condition technological parameter that generates the hole, repetitive operation until the hole on the A face all be put on the A section chromosome;

Same method generates B section chromosome, and determines chromosomal related process parameter, repeats aforesaid operations and produces new item chromosome, until chromosome number reaches colony's number;

4.3) appropriate function calculation

Calculate every chromosomal appropriateness value in the colony according to optimization aim, computing method are as described in the step 3, and for processing, wait, the traveling time of determining tool sharpening, wherein key issue is to determine the stand-by period of tool sharpening, the concrete following several situation that is divided into of calculating, with reference to Fig. 2:

Situation 1, when $t_{\mathrm{Aj}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ l _B∈ [1, n _B] time,

If a. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$

So $t_{\mathrm{Btw}}=(t_{\mathrm{Aj}}+t_{\mathrm{Ajm}})-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$ Shown in Fig. 2 a,

If b. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$

So left cutter 1,2 stand-by period of right cutter are 0, shown in Fig. 2 b,

Situation 2, when $t_{\mathrm{Aj}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ l _B∈[1，n _B]，

The stand-by period of left cutter 1 is: $t_{\mathrm{Ajw}}=t_{\mathrm{Aj}}-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$

If c. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$

So $t_{\mathrm{Btw}}=t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$ Shown in Fig. 2 c,

If d. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$

The stand-by period of so right cutter 2 is t _Btw=0, shown in Fig. 2 d,

4.4) carry out genetic manipulation

Produce new colony by the simulation genetic process,

A. replicate run

Choose the chromosome of appropriate functional value minimum in the current colony and put into new colony;

B. interlace operation

According to probability P _cIntersect, choose at random two chromosomes in the current colony, the A in the chiasmatypy, B section produce two new chromosomes and put into new colony;

C. mutation operation

According to probability P _mMake a variation, choose at random the item chromosome in the current colony, extract the regeneration that any one gene carries out technological parameter in A, B section respectively, newly-generated chromosome is put into new colony;

D. supply colony

Use the initialized method of colony to generate new chromosome, supply colony's chromosome number;

4.5) the algorithm end

If reach the iterations of algorithm then stop computing, the minimum chromosome of output appropriateness value, otherwise the operation of repeating step 4.3-step 4.4.

Step 5: the chromosome structure of the appropriateness value minimum that obtains according to step 4, the numerical control code establishment is carried out in the processing of hole in piece part, determine speed of feed, cutter rotating speed, cutter radius compensation, translational speed and the cutting line of left and right sides cutter in the NC Machining Process, the numerical control code establishment standard of combining with digital control lathe, finish the establishment of numerical control code, the simulation feed tries processing and formal processing at last.The coding step comprises following several:

5.1) machining starting point is set: respectively take first machining hole of two A, B face as machining starting point;

5.2) spindle parameters is set: rotating speed and speed of feed;

5.3) set and process instruction: straight-line feed, withdrawing;

5.4) set wait instruction: machining coordinate, the speed of mainshaft remain unchanged;

5.5) set move: travelling workpiece or cutter are processed to next hole.

Embodiment

All apertures are 5mm, f _Min=0mm, f _Max=0.36mm, N _Min=0rpm, N _Max=130rpm.The position signal in hole is blind hole as shown in Figure 1, and correlation parameter is as shown in table 1.The Java programming realizes above-mentioned algorithm.

The a plurality of blind hole machined parameters of the left and right cutter of table 1 (mm of unit)

Parameter

Value

Parameter

Value

Parameter

Value

Parameter

Value

h A1

18

h B2

6

O A2

40

O B3

38

h A2

10

h B3

17

O B1

12

V w(mm/s)

25

h B1

15

O A1

20

O B2

28

V t(mm/s)

30

Because worktable can rotate around Z axis, so two kinds of prioritization schemes are arranged: scheme 1 is left cutter 1 processing A face, right cutter 2 processing B faces; Scheme 2 is left cutter 1 processing B faces, right cutter 2 processing A faces, and result of calculation is respectively shown in table 2, table 3.The appropriate functional value of the algorithm of employing scheme 1, scheme 2 is distinguished as shown in Figure 3, Figure 4 with the variation tendency of iterations, can find out that algorithm just can obtain near-optimum solution under very short iterations, and keep stablizing downward trend, show feasibility and the validity of the inventive method.

The optimum results of table 2 scheme 1

The optimum results of table 3 scheme 2

More above-mentioned two schemes, therefore scheme 1 optimum carries out the establishment of numerical control code according to its result, finally finishes the control of process.Code is as follows:

Left cutter 1 (the B1 starting point is reference zero)

Right cutter 2 (the A2 starting point is reference zero)

The present invention can be used in the technological design and optimizing process of restructural drilling machine porous processing in parallel, has following beneficial effect: 1) under the conditions such as geometric parameter that satisfy machine tooling operating mode, cutter life constraint and hole, use algorithm can obtain rapidly the machined parameters in hole; 2) on the basis that technological parameter is determined, the shortest in target to realize process time, the processing route in generation hole; 3) according to the structural constraint of lathe, generate the processing simulation process of cutter and time correlation; 4) the inventive method also can be used for technological design and the optimization in other multi-hole parallel processing situation.

Claims (2)

1. multi-hole parallel processing method based on genetic algorithm, carry out porous processing as application take restructural drilling numerically-controlled machine in parallel, left cutter (1) only has the degree of freedom of X-axis traverse feed, the degree of freedom that right cutter (2) has X-axis laterally and Z axis vertically moves, platen moves and can rotate around Z axis along Z axis, its characteristics are: the method is specifically implemented according to following steps

Step 1: determine to be installed in workpiece (3) on the restructural drilling numerically controlled machine in parallel and the Z-direction translational speed V of right cutter (2) _w, V _t

Step 2: determine that each intends the related process parameter of machining hole on workpiece (3) and the machined surface thereof, the related process parameter comprises following several:

BHN-part material hardness, unit is HB,

The diameter in d-hole, unit are mm,

n _AThe number in hole on the-A face,

f _AjThe speed of feed in j hole the on-processing A face, j=1,2 ..., n _A, unit is mm/rev,

n _BThe number in hole on the-B face,

f _BtThe speed of feed in t hole the on-processing B face, t=1,2 ..., n _B, unit is mm/rev,

h _AjThe degree of depth in j hole the on-processing A face, unit is mm,

h _BtThe degree of depth in t hole the on-processing B face, unit is mm,

N _AjThe cutter rotating speed in j hole the on-processing A face, unit is rpm,

N _BtThe cutter rotating speed in t hole the on-processing B face, unit is rpm,

O _AjThe Z-direction coordinate figure in j hole the on-face A, unit are mm,

O _BtThe Z-direction coordinate figure in t hole the on-face B, unit are mm;

Step 3: set up process optimization target and constraint condition

3.1) objective function is that the hole is the shortest process time: F=Min{max (T ₁, T ₂),

Wherein, T ₁Be the deadline of left cutter (1): $T_1=\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}[t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}],$

T ₂Be the deadline of right cutter (2): $T_2=\underset{t=1}{\overset{n_B}{\mathrm{\&Sigma;}}}[t_{\mathrm{Bt}}+t_{\mathrm{Btm}}+t_{\mathrm{Btw}}],$

t _AjBe the drilling time in hole: $t_{\mathrm{Aj}}=\frac{h_{\mathrm{Aj}}}{f_{\mathrm{Aj}}{N}_{\mathrm{Aj}}},$ j＝1，2，...，n _A，

t _BtBe the drilling time in hole: $t_{\mathrm{Bt}}=\frac{h_{\mathrm{Bt}}}{f_{\mathrm{Bt}}{N}_{\mathrm{Bt}}},$ t＝1，2，...，n _B，

t _AjmBe the part traveling time: $t_{\mathrm{Ajm}}=\frac{|O_{A(j+1)}-O_{\mathrm{Aj}}|}{V_w},$ j＝1，2，...，n _A-1，

t _BtmTraveling time for right cutter (2):

$t_{\mathrm{Btm}}=\frac{(O_{A(j+1)}-O_{\mathrm{Aj}})+(O_{B(t+1)}-O_{\mathrm{Bt}})}{V_t},$

In the above-mentioned formula, t _Ajw, t _BtwBe respectively the processing stand-by period of left cutter (1), right cutter (2), this time determines according to machining state in optimizing process,

3.2) constraint condition:

3.21) left cutter (1), right cutter (2) speed of feed and rotating speed constraint comprise:

f _Amin＜f _Aj≤f _Amax，j＝1，2，...，n _A，

f _Bmin＜f _Bt≤f _Bmax，t＝1，2，...，n _B，

N _Amin＜N _Aj≤N _Amax，j＝1，2，...，n _A，

N _Bmin＜N _Bt≤N _Bmax，t＝1，2，...，n _B，

In the above-mentioned formula, f _Min, f _MaxBe respectively minimum and the maximal value of left cutter (1), right cutter (2) speed of feed; N _Min, N _MaxBe respectively minimum and the maximal value of left cutter (1), right cutter (2) rotating speed;

3.22) the life-span constraint of left cutter (1), right cutter (2)

$24000=\frac{\mathrm{\&pi;d}}{12}{{\mathrm{NT}}_L}^{0.15}{f}^{0.6}{d}^{0.3}\&times;{\left(\mathrm{BHN}\right)}^{1.25},$

In the above-mentioned formula, T _LBe cutter life, unit minute is convenient to optimize and calculates, and adapts to the multi-state condition of work, and the cutter life constraint is converted into following form:

$\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}\frac{t_{\mathrm{Aj}}}{T_{\mathrm{LAj}}}=\underset{j=1}{\overset{n_A}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Aj}}^{5.67}{f}_{\mathrm{Aj}}^3\&times;\frac{h_{\mathrm{Aj}}{d}_{\mathrm{Aj}}^{0.667}\&times;{\left(\mathrm{BHN}\right)}^{8.33}}{1.26\&times;{10}^{33}}\&le;1,$

$\underset{t=1}{\overset{n_B}{\mathrm{\&Sigma;}}}\frac{t_{\mathrm{Bt}}}{T_{\mathrm{LBt}}}=\underset{j=1}{\overset{n_B}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Bt}}^{5.67}{f}_{\mathrm{Bt}}^3\&times;\frac{h_{\mathrm{Bt}}{d}_{\mathrm{Bt}}^{0.667}\&times;{\left(\mathrm{BHN}\right)}^{8.33}}{1.26\&times;{10}^{33}}\&le;1,$

Wherein, T _LAjBe the cutter life of cutter under the operating mode in j hole of A face processing;

T _LBtBe the cutter life of cutter under the operating mode in t hole of B face processing;

d _AjDiameter for j hole on the A face;

d _BtDiameter for t hole on the B face;

Step 4: genetic algorithm for solving

4.1) genetic coding

Chromosome is divided into two sections of A, B represents respectively A, B face, each gene on the chromosome represents machining hole, has comprised the related process parameter in hole, and the order of gene represents the processing sequence in hole;

4.2) the initial population generation

Certain hole of choosing at random on the A face is placed on the chromosomal A section, and is satisfying under speed of feed and the rotating speed constraint condition technological parameter that generates the hole, repetitive operation until the hole on the A face all be put on the A section chromosome;

Same method generates B section chromosome, and determines chromosomal related process parameter, repeats aforesaid operations and produces new item chromosome, until chromosome number reaches colony's number;

4.3) appropriate function calculation

Calculate every chromosomal appropriateness value in the colony according to optimization aim, computing method are as described in the step 3, and this moment, key issue was to determine the stand-by period of tool sharpening, specifically was divided into following several situation:

Situation 1, when $t_{\mathrm{Aj}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ l _B∈ [1, n _B] time,

If a. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ So $t_{\mathrm{Btw}}=(t_{\mathrm{Aj}}+t_{\mathrm{Ajm}})-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$

If b. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ So left cutter (1), right cutter (2) stand-by period are 0,

Situation 2, when $t_{\mathrm{Aj}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ l _B∈[1，n _B]，

The stand-by period of left cutter (1) is: $t_{\mathrm{Ajw}}=t_{\mathrm{Aj}}-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$

If c. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}\&GreaterEqual;\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ So $t_{\mathrm{Btw}}=t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}-(\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}}),$

If d. $t_{\mathrm{Aj}}+t_{\mathrm{Ajm}}+t_{\mathrm{Ajw}}<\underset{t=1}{\overset{l_B}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Bt}}+\underset{t=1}{\overset{l_B+1}{\mathrm{\&Sigma;}}}{t}_{\mathrm{Btm}},$ The stand-by period of so right cutter (2) is t _Btw=0,

4.4) carry out genetic manipulation

Produce new colony by the simulation genetic process,

A. replicate run

Choose the chromosome of appropriate functional value minimum in the current colony and put into new colony;

B. interlace operation

According to probability P _cIntersect, choose at random two chromosomes in the current colony, the A in the chiasmatypy, B section produce two new chromosomes and put into new colony;

C. mutation operation

According to probability P _mMake a variation, choose at random the item chromosome in the current colony, extract the regeneration that any one gene carries out technological parameter in A, B section respectively, newly-generated chromosome is put into new colony;

D. supply colony

Use the initialized method of colony to generate new chromosome, supply colony's chromosome number;

4.5) the algorithm end

If reach the iterations of algorithm then stop computing, the minimum chromosome of output appropriateness value, otherwise the operation of repeating step 4.3-step 4.4;

Step 5: the chromosome structure of the appropriateness value minimum that obtains according to step 4, the numerical control code establishment is carried out in the processing of hole in piece part, determine speed of feed, cutter rotating speed, cutter radius compensation, translational speed and the cutting line of left and right sides cutter in the NC Machining Process, the numerical control code establishment standard of combining with digital control lathe, finish the establishment of numerical control code, the simulation feed tries processing and formal processing at last.

2. method according to claim 1, it is characterized in that: the coding in the described step 5 specifically comprises following several:

5.1) machining starting point is set: respectively take first machining hole of two A, B face as machining starting point;

5.2) spindle parameters is set: rotating speed and speed of feed;

5.3) set and process instruction: straight-line feed, withdrawing;

5.4) set wait instruction: machining coordinate, the speed of mainshaft remain unchanged;

5.5) set move: travelling workpiece or cutter are processed to next hole.

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