CN104809307A - Engine right-angle pipeline genetic algorithm planning method oriented to Manhattan space - Google Patents

Abstract

The invention discloses an engine right-angle pipeline genetic algorithm planning method oriented to the Manhattan space. The method comprises the following specific steps: the geometrical information of an aero-engine model is extracted through the secondary development technology in a UG model; a .txt file of the extracted information is then imported into the Matlab software, and a pipeline path is automatically calculated through the technology; a .txt file of the calculation result is finally returned to the UG model through the secondary development technology, so as to achieve visualization of an aero-engine right-angle pipeline curved-surface layout plan. The method provided by the invention has the advantages that regarding the model trend of the right-angle pipeline layout, a fixed-length individual coding method is designed to solve the pipeline layout problem; appropriate evaluation functions are established for targets such as the minimum pipeline length, the minimum number of pipeline elbows, and the minimum energy value; an engine pipe layout space obstacle model is described through a curved-surface polygon; obstacle avoidance handling adopts the approximate geodesic line intersection method. The method provided by the invention achieves the automatic and optimum engine right-angle pipeline design.

Description

Towards the engine direct cornue road genetic algorithm planing method in space, Manhattan

Technical field

The present invention relates to the optimization field of aeromotor surface right angle pipe-line layout, be specifically related to a kind of engine direct cornue road genetic algorithm planing method towards space, Manhattan.

Background technology

The pipeline to properties of product and reliability important that complex equipment is as a large amount of in aeromotor comprises usually, pipeline installation needs to consider space constraint and rule constrain, and hand laid can cause repeatedly revising and inefficiency.Different from traditional assembling, the difficult point of pipeline laying is more that the complexity of pipeline shape is with uncertain.A typical aeromotor comprises about 200 pipelines usually, and pipeline needs to be laid in Complex Constraints rotary space, and also need to meet various Engineering constraint, its process is very complicated and consuming time simultaneously.For realizing the automatic laying of pipeline, many scholars are studied pipe-line layout's problem, and achieve certain achievement, but due to pipe-line layout constraint complicacy, also do not form the Theories and methods of a set of maturation at present.

The determination of pipe-line layout is a very complicated process, both at home and abroad in outside pipeline laying field still with hand laid, be adjusted to main, lay random large, not easily, the cycle of laying is long, and cost is high, constrains the progress of whole engineering in amendment.Especially in the last few years, the continuous maturation of computer technology, begin one's study the research of laying both at home and abroad that utilize computing machine to assist and carry out pipeline, although achieve certain achievement, but or carry out pipeline laying with man-machine interaction mode, pipeline avoids obstacle also needs artificial intervention just can complete, and so still constrains the development of pipe-line layout's design to a certain extent.

Summary of the invention

In order to solve the automatic laying problem of engine crankcase curved surface right angle pipeline, the invention provides a kind of engine direct cornue road genetic algorithm planing method towards space, Manhattan, walk upwards in the pattern of right angle pipe-line layout, devise the measured length individual UVR exposure method for pipe-line layout's problem; Establish that length of pipe is the shortest, channel bend number is minimum, energy value is minimum and successfully avoid the suitable evaluation function of these targets of obstacle; Have employed the curved surface circuit design that approximate geodesic method solves engine; Adopt approximate geodesic line to ask the method for friendship to solve pipeline and keep away barrier problem.This invention improves the efficiency of pipeline laying, realizes robotization and the optimization of engine direct angle circuit design.

For achieving the above object, the technical scheme that the present invention takes is:

Towards the engine direct cornue road genetic algorithm planing method in space, Manhattan, comprise the steps:

S1, in UG model, extract aeromotor stringing space environment information and pipeline terminal point information by secondary exploitation technology, then, the .txt file of information extraction is imported Matlab software, Disorder Model in initialization pipe-line layout, after determining the initial parameter collection of pipeline laying, parameter is encoded;

S2, according to designed encoding mechanism initialization Population in Genetic Algorithms;

S3, calculate each objective function: length of pipe, elbow number, energy value; Process constraint condition: solve and keep away barrier penalty (annex obstacle, electrical areas etc. other be not suitable for stringing region);

S4, set up evaluation function, evaluate population, meet stopping criterion, extract the .txt file of its result of calculation, returned in UG model by secondary exploitation technology, realize aeromotor right angle pipeline curved surface placement scheme visual;

S5, do not meet stopping criterion, select several body by roulette wheel selection method and breed;

S6, random pair, carry out interlace operation by crossover probability, and it is individual to generate two sons;

S7, according to mutation probability variation binary string in some position;

S8, execution T=T+1 operation, return step S3 and continue operation, know that iteration terminates, till finding optimal path.

Wherein, the acquisition methods of described Disorder Model is: the coordinate A (ρ of given two somes point _a, θ _a, z _a) and B (ρ _a, θ _a, z _a), apply approximate geodesic line on the surface to replace straight line at the casing of engine, and then realize curved surface stringing.

Wherein, the evaluation function of the method establishment of the employing linear weighted function in described step S4 is:

F(P)＝α×L(p)+β×B(p)+δ×E(p)+λ×O(p)

In formula, L (P): delegated path length; B (P): the elbow number of pipeline; E (P): the energy value in path; O (P): penalty function, whether delegated path is by obstacle, and obstacle refers to the region of other applicable stringing such as engine accessory power rating, electrical areas or cabling.

Wherein, in described step S1, the method for parameter coding is: the starting point of given path and terminal, and be set as 1 by from the trend of origin-to-destination through certain any path, be set as 0 by from the trend of origin-to-destination through the path of another point, then carry out path code.

Wherein, adopt approximate geodesic line to ask friendship mode to judge that whether pipeline path is crossing with obstacle, it can be decomposed into further and judge 2 approximate geodesic lines whether intersection problems, and concrete scheme is:

If engine surface two approximate geodesic lines the two-dimensional columns coordinate of end points be respectively (θ _a, z _a), (θ _b, z _b) and (θ _c, z _c), (θ _d, z _d).Then introduce following parametric equation and represent two approximate geodesic lines:

Approximate geodesic line $\left\{\begin{array}{c}\mathrm{\θ}={\mathrm{\θ}}_A+({\mathrm{\θ}}_B-{\mathrm{\θ}}_A)\·m\\ z=z_A+(z_B-z_A)\·m\end{array}\right.0\≤m\≤1---\left(1\right)$

Approximate geodesic line $\left\{\begin{array}{c}\mathrm{\θ}={\mathrm{\θ}}_C+({\mathrm{\θ}}_D-{\mathrm{\θ}}_C)\·n\\ z=z_C+(z_D-z_C)\·n\end{array}\right.0\≤n\≤1---\left(2\right)$

Line segment is represented when parameter 0≤m≤1 line segment is represented during 0≤n≤1

For solving approximate geodesic intersection point, first solve parameter m, n here.So above-mentioned equation is arranged be:

$\left\{\begin{array}{c}{\mathrm{\θ}}_A+({\mathrm{\θ}}_B-{\mathrm{\θ}}_A)\·m={\mathrm{\θ}}_C+({\mathrm{\θ}}_D-{\mathrm{\θ}}_C)\·n\\ z_A+(z_B-z_A)\·m=z_C+(z_D-z_C)\·n\end{array}\right.---\left(3\right)$

That is:

$\left\{\begin{array}{c}({\mathrm{\θ}}_B-{\mathrm{\θ}}_A)\·m-({\mathrm{\θ}}_D-{\mathrm{\θ}}_C)\·n={\mathrm{\θ}}_C-{\mathrm{\θ}}_A\\ (z_B-z_A)\·m-(z_D-z_C)\·n=z_C-z_A\end{array}\right.---\left(4\right)$

If $D=\left|\begin{array}{cc}{\mathrm{\θ}}_B-{\mathrm{\θ}}_A& {\mathrm{\θ}}_C-{\mathrm{\θ}}_D\\ z_B-z_A& z_C-z_D\end{array}\right|,$ Then

As D=0, two approximate geodesic lines are parallel or overlap, and are considered as without intersection point.

When D ≠ 0, $m=m^{\′}=\frac{1}{D}\left|\begin{array}{cc}{\mathrm{\θ}}_C-{\mathrm{\θ}}_A& {\mathrm{\θ}}_C-{\mathrm{\θ}}_D\\ z_C-z_A& z_C-z_D\end{array}\right|,n=n^{\′}=\frac{1}{D}\left|\begin{array}{cc}{\mathrm{\θ}}_B-{\mathrm{\θ}}_A& {\mathrm{\θ}}_C-{\mathrm{\θ}}_A\\ z_B-z_A& z_C-z_A\end{array}\right|$

When parameter 0≤m '≤1 and 0≤n '≤1 time be similar to geodesic line just have intersection point, intersection point is: (θ _a+ (θ _b-θ _a) m ', z _a+ (z _b-z _a) m ') or (θ _c+ (θ _d-η _c) n ', z _c+ (z _d-z _c) n ').

Otherwise, approximate geodesic line without intersection point.

The present invention has following beneficial effect:

By adopting this optimization method, consider the requirement of engineering rule, it is fast to search plain speed.In pipeline optimizing, realize robotization, the time of laying shortens greatly, and what improve pipeline lays efficiency.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of a kind of engine direct cornue road genetic algorithm planing method towards space, Manhattan of the embodiment of the present invention.

Fig. 2 is the coded system schematic diagram of path L in the embodiment of the present invention.

Fig. 3 is the coded system schematic diagram of path R in the embodiment of the present invention.

Fig. 4 is mapping relations general illustration between pipeline path code and pipeline path.

Fig. 5 is the example structural representation in the embodiment of the present invention.

Fig. 6 is that the engine pipelines simplified in the embodiment of the present invention lays model.

Embodiment

In order to make objects and advantages of the present invention clearly understand, below in conjunction with embodiment, the present invention is further elaborated.Should be appreciated that concrete enforcement example described herein is only in order to explain the present invention, is not intended to limit the present invention.

As shown in Figure 1, embodiments provide a kind of engine direct cornue road genetic algorithm planing method towards space, Manhattan, comprise the steps:

S1, in UG model, extracted environmental information and the pipeline terminal point information on aeromotor surface by secondary exploitation technology, then, by the .txt file of information extraction importing Matlab software, after determining the parameter set of pipeline laying, parameter is encoded;

Disorder Model in S2, initialization pipe-line layout and Population in Genetic Algorithms;

S3, calculate each objective function: path, elbow number, energy value, keep away barrier;

S4, set up evaluation function, evaluate population, meet stopping criterion, extract the .txt file of its simulation result, returned in UG model by secondary exploitation technology, realize aeromotor right angle pipeline curved surface placement scheme visual;

S5, do not meet stopping criterion, select several body by roulette wheel selection method and breed;

S6, random pair, carry out interlace operation by crossover probability, and it is individual to generate two sons;

S7, according to mutation probability variation binary string in some position;

S8, execution T=T+1 operation, return step S3 and continue operation, know that iteration terminates, till finding optimal path.

Lay space to obtain by the following method:

It is rotary space between interior casing and nacelle that aeroengine pipeline lays space, and the outside surface of interior casing is considered to the approximate surface of revolution or the surface of revolution of the generation around certain straight line rotates of a curve usually, will be more convenient so discuss this problem of laying in cylindrical coordinates situation.If the bus I between the surface of interior casing and nacelle inside surface _j, I _wequation is respectively

I _J： $\left\{\begin{array}{c}{F}_J(\mathrm{\ρ},z)=0\\ \mathrm{\θ}=0\end{array}\right.0\≤z\≤h_0---\left(5\right)$

I _W： $\left\{\begin{array}{c}{F}_w(\mathrm{\ρ},z)=0\\ \mathrm{\θ}=0\end{array}\right.0\≤z\≤h_0---\left(6\right)$

In formula, h ₀represent the axial length of aero-engine casing.

In order to the convenience expressed later, by I _jand I _wbe denoted as ρ=f respectively _j(z) and ρ=f _w(z).Therefore the space of laying of pipeline can represent by formula below:

$\left\{\begin{array}{c}{f}_J\left(z\right)<\mathrm{\&rho;}<f_W\left(z\right)\\ 0\&le;\mathrm{\&theta;}\&le;2\mathrm{\&pi;}\\ 0\&le;z\&le;h_0\end{array}\right.---\left(7\right)$

Mainly adopt least square method to carry out matching and obtain casing bus equation with this.First be the coordinate information of casing surface bus up-sampling point in extracting in 3 d modeling software UG model.The rectangular coordinate of setting sampled point is A _i(x _i, y _i, z _i), i=1,2 ... L, N, thus the two-dimensional columns coordinate that can obtain sampled point is B accordingly _i(z _i, ρ _i), i=1,2 ... L, N, wherein, finally, application least square method carries out matching to curve, and then we can obtain the bus equation ρ=f on interior casing surface _j(z).

Disorder Model is set up by the following method:

The basic thought of curved surface stringing is: apply approximate geodesic line to replace straight line thus to carry out seeking footpath projection on the casing surface of engine with laying in aspect.

Coordinate A (the ρ of given two somes point _a, θ _a, z _a) and B (ρ _a, θ _a, z _a), approximate Geodesic active contour can be set up and be shown below.

$\left\{\begin{array}{c}{x}_i=f_J(z_A+(z_B-z_A)\&CenterDot;({\mathrm{\&theta;}}_i-{\mathrm{\&theta;}}_A)/({\mathrm{\&theta;}}_B-{\mathrm{\&theta;}}_A))\&CenterDot;\cos \left({\mathrm{\&theta;}}_i\right)\\ y_i=f_J(z_A+(z_B-z_A)\&CenterDot;({\mathrm{\&theta;}}_i-{\mathrm{\&theta;}}_A)/({\mathrm{\&theta;}}_B-{\mathrm{\&theta;}}_A))\&CenterDot;\sin \left({\mathrm{\&theta;}}_i\right)\\ z_i=z_A+(z_B-z_A)\&CenterDot;({\mathrm{\&theta;}}_i-{\mathrm{\&theta;}}_A)/({\mathrm{\&theta;}}_B-{\mathrm{\&theta;}}_A)\end{array}\right.---\left(8\right)$

Wherein ρ=f _jz () is casing bus equation.

Further, in 2D or 3d space, by the method, irregular obstacle can be changed into polygon, therefore in pipeline laying aspect, we use approximate geodesic line instead of straight line to describe obstacle, this pretreated method, just generates polygonal apex coordinate, can not affect asking for of shortest path.

The coding method of manhatton distance is:

Adopt while genetic algorithm carries out programming, lay in problem what solve right angle pipeline, propose the encoding mechanism based on manhatton distance.The starting point of given path and terminal point coordinate are respectively A (x _a, y _a) and B (x _b, y _b), path L represents and arrives B point from A point through P point, path R represents and arrives B point from A point through Q point, the trend being defined through the path L of P point can be set as 1, path R trend through Q point is set as 0, so far we can obtain the coded system of this two paths, and the coded system of Fig. 2 respective path L is [x _a, y _a, 1, x _b, y _b]; The coded system of Fig. 3 respective path R is [x _a, y _a, 0, x _b, y _b].Fig. 4 gives the mapping relations figure between certain complete pipeline coding and pipeline path.

The foundation of evaluation function and penalty:

Judging on curved surface path and obstacle intersection problems, have employed the method that approximate geodesic line asks friendship, by judging to ask the position relationship of intersection point and the barrier obtained to judge whether with barrier crossing: if intersection point intersects in this path of barrier internal representation and obstacle, then then find next paths, otherwise this path meets keeps away barrier requirement.

When avoiding obstacle, ensure that pipeline installs the installation of being convenient to pipeline and fixing along the annex of surrounding and equipment, for addressing this problem, we adopt evaluation function--and energy value is described.Energy value can represent with E (P).In order to improve counting yield, the present invention is based on non-grid modeling method--energy value.Its specific design thought is: get on each obstacle a bit as energy source, generally, get the center of obstacle as energy source, a given path meeting given rule, each point on calculating path is to the distance of energy source, the summation of this distance is exactly energy value, and energy value is less represents the obstacle of given path the closer to surrounding, more meets installation and fixing requirement.

Adopt the evaluation function of the method establishment system of linear weighted function:

F(P)＝α×L(p)+β×B(p)+δ×E(p)+λ×O(p) (9)

In formula, L (P): delegated path length; B (P): the elbow number of pipeline; E (P): the energy value in path; O (P): penalty function, whether delegated path is by obstacle, and obstacle refers to the region of other applicable stringing such as engine accessory power rating, electrical areas or cabling.

Suitable coefficient value is obtained after normalized.

Embodiment

Lay model for the engine pipelines simplified, verify feasibility of the present invention.The parameter choose of genetic algorithm is recommended value herein: population scale is M=80, maximum iteration time T=200; Crossover probability Fi=0.6, mutation probability is Bi=0.05, if objective function is:

F _O(s)＝2000/(1*lsum+30*bend+2000*pe+10*nl) (10)

Wherein:

Lsum-path;

Bend-channel bend number;

Pe-penalties;

Nl-energy value.

Be set to the starting point on fixed tube road and terminal and Disorder Model, each performance index of pipeline laying can be obtained by MATLAB emulation:

Evolutionary generation: k=200;

The real number form of optimum individual correspondence coding: xo=108.5000 83.5000 154.5000109.5000 154.5000 109.5000 0 1.0000 0 1.0000;

Optimum individual adaptive value: Max=0.4831;

Length of pipe: lsum=290;

Elbow number: bend=5;

Keep away barrier penalty value: pe=0;

Energy value: nl=370;

Comprise the path node of point at the whole story, encoded point and path flex point and reject the array that duplicate node obtains:

sxyt1＝50.0000 25.0000

50.0000 83.5000

108.5000 83.5000

108.5000 109.5000

154.5000 109.5000

154.5000 175.0000

190.0000 175.0000

Because program is in the middle of operational process, when there being duplicate node, this program can be fallen by automatic rejection.Time used during final program end of run is 29.977481 seconds.

Pipeline can be obtained carry out simulating, verifying in MATLBA software after on plane pipeline, lay path, as shown in Figure 5, pipeline laying result is visual in the engine pipelines laying system of exploitation, as shown in Figure 6, what can be clearly seen that pipeline lays effect, demonstrates the validity of this invention.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (5)

1., towards the engine direct cornue road genetic algorithm planing method in space, Manhattan, it is characterized in that, comprise the steps:

S1, in UG model, extract aeromotor stringing space environment information and pipeline terminal point information by secondary exploitation technology, then, the .txt file of information extraction is imported Matlab software, Disorder Model in initialization pipe-line layout, after determining the initial parameter collection of pipeline laying, parameter is encoded;

S2, according to designed encoding mechanism initialization Population in Genetic Algorithms;

S3, calculate each objective function: length of pipe, elbow number, energy value; Process constraint condition: solve and keep away barrier penalty (annex obstacle, electrical areas etc. other be not suitable for stringing region);

S4, set up evaluation function, evaluate population, meet stopping criterion, then extract the .txt file of its result of calculation, returned in UG model by secondary exploitation technology, realize aeromotor right angle pipeline curved surface placement scheme visual;

S5, do not meet stopping criterion, select several body by roulette wheel selection method and breed;

S6, random pair, carry out interlace operation by crossover probability, and it is individual to generate two sons;

S7, according to mutation probability variation binary string in some position;

S8, execution T=T+1 operation, return step S3 and continue operation, until iteration terminates, till finding optimal path.

2. the engine direct cornue road genetic algorithm planing method towards space, Manhattan according to claim 1, it is characterized in that, the acquisition methods of described Disorder Model is: the coordinate A (ρ of given two somes point _a, θ _a, z _a) and B (ρ _a, θ _a, z _a), apply approximate geodesic line on the surface to replace straight line at the casing of engine, and then realize curved surface stringing.

3. the engine direct cornue road genetic algorithm planing method towards space, Manhattan according to claim 1, is characterized in that, the evaluation function in described step S4 adopts the method establishment of linear weighted function, and this evaluation function is:

F(P)＝α×L(p)+β×B(p)+δ×E(p)+λ×O(p)

In formula, L (P): delegated path length; B (P): the elbow number of pipeline; E (P): the energy value in path; O (P): penalty function, whether delegated path is by obstacle, and obstacle refers to the region of other applicable stringing such as engine accessory power rating, electrical areas or cabling.

4. the engine direct cornue road genetic algorithm planing method towards space, Manhattan according to claim 1, it is characterized in that, in described step S1, the method for parameter coding is:

The starting point of given path and terminal, and be set as 1 by from the trend of origin-to-destination through certain any path, be set as 0 by from the trend of origin-to-destination through the path of another point, then carry out path code.

5. the engine direct cornue road genetic algorithm planing method towards space, Manhattan according to claim 1, it is characterized in that, adopt approximate geodesic line to ask friendship mode to judge that whether pipeline path is crossing with obstacle, it can be decomposed into further and judge 2 approximate geodesic lines whether intersection problems.