Of method of treatment of the aperture in CAM system optimize processing

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source:MAJA CNC Machining

CAD/CAPP/CAM system has all in all place in CIMS. In first phase project of some enterprise CIMS, came true to be based on product data to manage (Product Data Management, of PDM) preliminary and compositive. The CAD/CAM trade that this project uses is I-DEAS with software, CAM system is platform with I-DEAS GM module, accept the craft kill that CAPP makes on one hand, accept the geometrical substance information of CAD on the other hand, make all sorts of treatment news, voluntary program knife orbit, handle module through postposition, generate the NC code that applies to system of different numerical control. Although achieved type CAPP to plan working procedure content, but did not restrain the treatment order inside a working procedure. If many treatment feature is contained inside working procedure, if machine many aperture, criterion its machine order to be decided by the modelling order of CAD system, because CAM processes hypostatic order of the feature,deliver by CAD those who come over. Design personnel takes no account of treatment order in molding process, the treatment that this means CAM to plan is random orderly, can add cutter track way from this, increase specific power consumption and reduce treatment efficiency, machine character especially when the amount is very large, this kind of problem is exposed more apparently. The " of " petty gain that the article uses maths to go up is algorithmic, in the course that builds numerical control code, undertook the feature is machined nod an optimization, solved this problem well. 1 maths describes diagnostic treatment to order an optimized mathematical model is the viatic trade problem in graph talking. The original shape of this one problem, the village that namely business of sell goods of a journey wants to be in from him sets out, to the sell goods of a few villages all round, every village goes, return jumping-off place finally, seek a his the shortest way. If abstraction becomes mathematical language, can say: Give to counterpoising to pursue completely, seek its shortest Hamilton way. If the graph is shown 1 times, this is by node V1 reachs what V6 comprises to counterpoising complete picture G, the filament between node calls a margin, the length that sets a line counterpoises for the edge the solution that; criterion thick wire is viatic trade problem. is right of this kind of problem seeking solution accurately is branch and delimiter law, it is once decided the bound is worth,branch and; of certain group value construct ceaselessly in searching a process, search no longer to be more than the branch that is equal to extent value, the bound that end up with is worth the optimum solution that is a problem. This method is gotten primely than enumerate law much, but fall in worst circumstance, its calculation is complex degree still be (N! ) second (the average calculation of enumerate law is complex degree for ( of 1/2( N - 1) ! ) ) . Accordingly, in real problem, need uses approximate algorithm to get the approximate and optimum solution of the problem, in order to avoid huge computational amount. "Cheap " algorithm is among them a better kind of approximate algorithm. to use this algorithm, do we assume: ? Zuo is by N node comprises pursue without Xiang Zhengquan, namely the random of G has a side between two node, and doesn't the edge have the random to; ② G do 3 node accord with: of trigonometry inequality relation? The authority side Zuo of of Quan of ∪ of of ァ of ＊ of to fold of of a surname of closely question of painful bamboo-plaited basket or suitcase of award Lie represents the distance between node, the suffix K(K that uses node Vk is node serial number) build two alignment S and T, is algorithmic description as follows: ? S={2 of buy of ァ ?1) , 3, ¨ ¨ , } of N , of T={1}; (2) is right each node in S, beg Dis Tmin=min(dist(j, k)) , (J ∈ S, of of of of K ∈ T) (assume among them Dis T(i, the function that J) leaves to beg node I and J span) (3) sets Distmin=dist(m, n) , (M ∈ S, of of of N ∈ T) is like Dist(m, n-1)-dist(n, n-1) ≤ Dist(m, n+1)-dist(n, n-1) , criterion between the N-1 that M inserts T, N, otherwise, between of the N that M inserts T, N+1. is of 0; to be like S= Ф in the positional buy of of M of S lieutenant general, end; turns otherwise (2) pace. T of is the primary road of a ceaseless augment, have a node only at first. The principle that of node M inserts is to seek the small to total distance contribution seat after inserting. If the optimum solution of viatic trade problem is Q , "The solution of cheap " algorithm is T, can prove T/Q<2 . The similar rate of this one result is not ideal, but be in actual in its solution and optimum solution are very adjacent, calculation is complex degree small, consequently we use this kind of algorithm. 2 programs of are algorithmic if program logic pursues 2 with the graph 3 are shown. Numerate in the document of code of initiative numerical control that handles module generation from postposition first each feature position, the coordinate of each features in be being machined namely is worth, after by " petty gain " algorithm gets the shortest way, principle of comply with mode is answered in writing original document. 3 actual test and verify afore-mentioned algorithm come true through encode, apply in the CAM subsystem of enterprise CIMS, obtained very good result. Graph 4 it is a wallboard kind the aperture of the spare parts machines sketch map. When is machining many aperture feature, for example, drill 12 hole, walk along cutter track diameter to be decided by order of CAD feature modelling, its value is not best, if pursue,5 are shown. After the algorithm that puts forward through the article is optimized, knife method result is shown 6 times like the graph, the dotted line in the graph is cutting tool method. In the postposition processing module that model of 4 epilogue author's will classical maths of viatic trade problem applies successfully at CAM subsystem, solved production real problem. Through actual test and verify, when digging central hole especially, because want cutting tool to complete the treatment of more than 80 aperture, the cutting tool method that optimizes through this method and the firsthand method look without processing are compared, shortened greatly handling time. Accordingly, the algorithm of the article accords with actual condition, method of the cutting tool when solving poriferous treatment the problem with inferior efficiency of expatiatory, treatment CNC MillingCNC Machining