Three-dimensional work laser cuts the automatic process designing of the edge

Summary: When giving out to undertake three-dimensional work laser cuts a margin, search the algorithm of the contrail of laser beam machining of workpiece border automatically. Approach a curve with straight line segment, approach normal of curved surface computation with small triangle plane, according to the relation of laser head and normal computation gives the attitude when laser head is machined, finish three-dimensional laser to cut a margin. Three-dimensional Laser Cutting already was made in the car, the domain such as aerospace receives wide application increasingly. Treatment of three-dimensional nowadays Laser Cutting is in the new product development of the car, already replaced a car to enclothe the model that decorate a border and punching model, become car manufacturer to shorten development cycle, reduce the cost, powerful tool that enhances competition ability. Undertake three-dimensional laser cuts a margin, the brim that must assure workpiece of edge of laser light beam moves, the incident direction to assure laser and workpiece surface are perpendicular at the same time, still ask laser head adjusts oneself attitude ceaselessly. Want to realize automatic process designing of three-dimensional Laser Cutting, be about to be able to produce the normal on the attrib border contour line of three-dimensional work and contour line automatically, control machine of laser beam machining next the athletic contrail that 3 mutual and perpendicular sharp movement walk out of contour line, control 2 runner shaft coming back to make laser agrees with normal from beginning to end at the same time, if the graph is shown 1 times,complete whole treatment process. Graph 1 laser beam machining pursues 2 curved surface piece 3 kinds of relations of joining together of P1, P2 pursue the disperse of 3 curves changes 1 implementation principle to want to realize afore-mentioned processes, should have work first three-dimensional model. The modelling of three-dimensional thin panel uses tool of curved surface modelling to finish. The three-dimensional figure that is used at cutting a margin often dispute closes curved surface, put in border certainly namely, this is the premise that searchs border automatically. Complex three-dimensional form is by a lot of curved surface piece the course is cut, joining together and into. Two curved surface piece pursue only when joining together of P1, P2 show 3 kinds of concerns 2 times. The attrib border the sum that the border of whole curved surface is each curved surface is subtractive its are communal the edge reachs his common share. For this, the common limit that should concern 3 kinds only and common share are found can. Curved surface is formed by the curve, because this problem translate into judges line segment of two spaces music whether coincide, if coincide, seek a coincide share. To simplify further of the problem seek solution, with fold line segment to approach dimensional curve. Actually, when undertaking teach programming of three-dimensional laser beam machining, the orbit cent that handlers machines workpiece face cut is a certain number of straight line segment, every paragraphs sharp starting point, terminus serves as show teach a point, through linear interpolation G01 the command makes broken line of space of laser head edge walks (the 3) that be like a graph. Show religion the dot is more, the dimensional contrail of actual cut is more flowing. Accordingly, to dimensional freedom curve, want to control bowstring to differ D only, can ask according to machining precision, approach dimensional curve with straight line segment, satisfy the requirement that Laser Cutting machines. Accordingly, judgement of final translate into snaps the issue twice line segment whether coincide, if coincide, seek a coincide share. the coincide part purify of all curved surface, those who remain is the border of workpiece. If flow chart of whole process algorithm pursues 4. The graph forms algorithmic basic idea automatically of method of border of 4 three-dimensional curved surface is attrib border and outspread law, namely preferential and aleatoric curved surface, save its border data, search with curved surface of its photograph adjacent, after removing common limit, amalgamative curved surface gets one new curved surface, save data of border of this curved surface, continue afore-mentioned measure, this are new curved surface expands ceaselessly, treat all curved surface, this are new curved surface is curved surface of actual and three-dimensional work, the attrib border data that saves is workpiece border. The attrib border contrail that what such getting is three-dimensional work is nodded by series namely (Xi, yi, zi)(i=1, 2, ... the dot line that N) forms, the motion of the head of normal direction laser that still asks to go out this a little bit to be in and attitude ability are affirmatory. The computation of vector of curved surface normal is as follows. Analytic curved surface is what give out by mathematical equation is smooth, but small curved surface, if the explicit equation of curved surface is V(s, t)=V[X(s, t) , y(s, t) , z(s, in T)] type, s, T is the parameter of curved surface, x, Y, Z is but small function, (V/s) × (V/t) is the normal between curved surface namely, be like equation to be concealed type, v(s, t)=V[s, t, g(s, t)] cannot get the normal of explicit definition right now, but normal vector is give out with gradient by function, namely concern of horn of F=[FFF]xyz graph 5 B, C and orientaton V(I, J, K) is common curved surface is OK approach approximately by polygon, on polygonal plane, take border to nod V1(xi, yi, two dot V2(xi+1 near Zi) , yi, zi) , V3(xi, yi+1, zi) , its fork is accumulated (V1V2) × (V2V3) is perpendicular at its plane. Can beg the normal of this bits of place on plane of photograph adjacent polygon with manage. Both take the normal that is in on average for this bits namely, do normalization processing to get V(I, j, k) . The relation according to horn of B of laser head attitude, C and normal direction (graph 5) , the seat that because manage laser head each this a little bit,does not give {I=sinBcosCJ=sinBsinCK=cosB inaccessibly and attitude come down certainly. Use NC instruction G01 X, y, z, b, c, workpiece of edge of head of F guiding laser is attrib border with perpendicular and incident laser bundle undertake three-dimensional Laser Cutting. What need points out is, horn of normal direction and B, C is not one to one correspondence relation, namely same normal is OK and corresponding many more boundless the attitude of laser, the flowing sex of the athletic process that this wants a basis to stimulate bareheaded and avoid collision to undertake optimizing choosing actor of B, C. Avoiding laser namely head and all round below the premise that workpiece collides, from a kind of attitude when laser head commutation arrives when another kind of attitude, answer to make the metabolic scope of horn of B, C little as far as possible. 2 last words the article is in according to asking to stimulate beam of light when three-dimensional laser beam machining the as perpendicular as workpiece surface from beginning to end characteristic in machining a process, the contrail of attrib border laser beam machining that gave out to seek work of three-dimensional curved surface automatically is algorithmic. This algorithm asks according to machining precision, approach a curve with straight line segment, approach curved surface to get the orbit dot of workpiece border and normal with small triangle plane, demand a laser head by the relation of laser head attitude and normal horn of the B of athletic process, C, finish three-dimensional laser to cut a margin. The three-dimensional laser beam machining that this method already developed in the author gets applied in LaserCAM2000 of software of automatic process designing, the result is favorable. CNC Milling