Summary: Be aimed at the demand that CNC Machining expands to high speed, put forward a kind new flexible add decelerate to control a method, this method can press an user given random adds decelerate curve or systematic trends generates add decelerate curve to undertake to the motion of the machine tool decelerate is controlled be addinged automatically, to obtain trends of first-rate machine tool character offers a new approach. Keyword: Numerical control is flexible and automatic add decelerate CNC Machining forward efficient way develops high speed. In high speed treatment, on one hand because feed rate is very rapid, to make full use of the effective job journey of the machine tool (count 100 millimeter) only commonly, must ask component of each coordinate motion can be achieved inside cutty time given rate can stay for an instant in high speed journey accurate. On the other hand, because the cutting time of high speed treatment shortens, the interval that change a knife shortens, machine tool motion is opened stop frequent, accordingly, shorten athletic component is opened those who stop transfer process time, also will have important sense. End of afore-mentioned two fields requirement arrive a bit, ask machine tool motion has cutty to add decelerate to transfer namely process. However, if consider to had shortened only from time,cross a process, and of incorrect machine tool add decelerate trends process to have reasonable control, be sure to bring very big impact to machine tool structure, light person will make its work normally hard, the person that weigh will injure machine tool component. Accordingly, how to make sure in machine tool motion smooth premise falls, implementation spends Cheng time with transferring the shortest those who be a target is best add decelerate to control the rule, those who make the machine tool has contented high speed to machine a requirement is admirable sum decelerate character, one of crucial problems that in already becoming system of contemporary numerical control to consider to develop, solve urgently. To solve this problem, ask on one hand numerical control system can because of machine and different, because different of from time to time comes,trends decides add, decelerate controls the rule (trends chooses or generate what suit with particular case photograph to add decelerate curve) namely. On the other hand, special method is used to implement this kind of dynamic rule in needing to controlling a system (add changefully, decelerate curve) . Apparent, what system of conventional numerical control uses is fixed adding decelerate to control a method is to cannot realize this one requirement. For this, article basis opens mind of type construction pilot, the sport that raises a kind to be able to charge a machine tool according to aleatoric curve logarithm undertakes adding decelerate pilot method automatically. This kind of method will add decelerate control automatically to be pushed by traditional fixed pattern to new flexible mode, to improve the dynamic performance of numerical control machine tool effectively exploration gives a new way. 1, flexible add decelerate pilot in system of conventional numerical control of basic idea , come true directly by systematic program commonly specific (wait like curve of linear, index) add decelerate automatically to control a function. Below type of this one party, want pair of systems add decelerate to character makes big change or increase to add decelerate newly to control the rule to must modify program of numerical control system, consequently average user cannot make by his apiration numerical control machine tool has first-rate to add decelerate performance. As contrary as this, what the article puts forward is flexible the principle that imposes decelerate to control square law to use a database, will add decelerate to control cent to be described to add decelerate with implement two parts, will add decelerate description and depart of systematic program photograph. Such, if want those who change a system to add decelerate to control the rule,need to be revised independently only add decelerate to describe data, and do not need to modify program of numerical control system, the real case that provides a kind to be able to press his for the user thereby changes the new method of the system that adds decelerate performance conveniently. In this one new control means falls, of numerical control system add decelerate automatically to control a function to will have height flexible wide-open to the user. The computation that adds decelerate to accomplish and control process and add decelerate curve appearance to have nothing to do, the article stores independently with the form of real time database add decelerate curve. Be about to given add, decelerate curve or generate automatically add, decelerate curve undertakes digitlizing handling, receive its disperse form, express its in order to count formal trends to deposit within numerical control system add, in decelerate curve library. In software of numerical control system, design general with add decelerate database content (curvilinear appearance) the control passageway that have nothing to do, finish independently by its impose decelerate computation and orbit control. The implementation principle of this method is shown 1 times like the graph. Graph 1 flexible in adding decelerate to control principle block diagram to pursue, add what decelerate is depositing an user to give in curvilinear library or the system generates automatically to add decelerate curve. When the system moves, the concerned control data that gives out according to data processing module above all and the machine tool that come from check measure feedback link move actually data undertakes decelerate is analysed adding. If need to impose decelerate control, inform a curve of the choice to module is singled out from inside adding decelerate curve library the most appropriate add decelerate curve, give out add decelerate to control an instruction to give add decelerate computation module, the adds decelerate curve computation to give current sampling cycle twinkling speed per hour that You Jigen occupies a make choice of is spent. Generate contrail of cutting tool motion by module of interpolation contrail computation further, give out statement of cutting tool exercise to send toward actuating device, finally by actuating device with the hope add decelerate to control component of motion of regular drive machine tool to move, the dynamic character that makes the machine tool moves thereby is achieved optimal. Next mask body discuss this environment to fall to add the implementation process of decelerate automatically. 2, flexible and automatic control to set quickly given quicken a curve (analytic curve or be not analytic curve) if the graph is shown 2 times, the form that expresses its in order to count as example now is deposited at adding decelerate curve library in. In the graph, fd always changes a volume to accelerate process feed rate (call its model speed to differ) below, td needs time to quicken process place (example quickens time) . According to quickening a curve several watches come true to quicken pilot course automatically to be as follows: Graph 2 quicken a curve automatically above all, according to the F1 of initiative feed speed of CNC Machining, quicken the F2 of hope feed speed after the process ends, beg piece quicken process speed to differ FD ＝ F2 - F1, calculate accordingly the FD of ＝ of K of ratio that gives effective rate difference and model rate difference ／ Fd (1) Nextpage next, the sampling that passes according to beginning current hour institute quickly is periodic a several N, computation gives T of ＝ of Tn of of of the time that check a watch. N ／ K (2) the T in type- - Tn of basis of sampling cycle is checked quicken curvilinear watch to be able to get Fn of model speed increment. From this calculable give course N the change of effective rate after interpolation is periodic measures Fn of ＝ of Fn of Δ .
K (3) is farther, will beg the N periodic rate that give to change the Fn that measure Δ to take the place of to leave type, the Δ of ＋ of F1 of ＝ of Fi of of of actual feed speed that begs a current sampling cycle Fn (4) is final, the Fi consideration that gets according to place is current the interpolation in sampling cycle is linear paragraph length, undertake orbit is calculated accordingly, can realize contented graph to quicken control automatically what 2 curves ask. 3, of control of flexible and automatic decelerate is set given decelerate curve is shown 3 times like the graph, the form that regards example as to be expressed in order to count its euqally as quickening control is deposited at adding decelerate curve library in. According to decelerate curve several watches realize course of automatic decelerate pilot to be as follows: Graph curve of 3 automatic decelerate above all, according to the F1 of initiative feed speed of CNC Machining, the F2 of hope feed speed after decelerate process ends, beg a decelerate process speed to differ FD ＝ F1 - F2. Next, according to with control same process quickly by type (1) , (2) begs a Tn of the time that check a watch, check decelerate curve watch to get Fn of model speed increment. From this calculable give course N the change of effective rate after interpolation is periodic measures FD of ＝ of Fn of Δ - Fn.
K (5) is farther, will beg the N periodic rate that give to change the Fn that measure Δ to take the place of to leave type, the F1 of ＝ of Fi of of of actual feed speed that begs a current sampling cycle - Δ Fn (6) is final, calculate according to Fi the interpolation in current sampling cycle is linear paragraph length, undertake orbit is calculated accordingly, can implement contented plan the automatic decelerate control that 3 curves ask. To automatic decelerate control, still need to forecast decelerate drop before decelerate, when to begin decelerate in order to decide. The basis that certain deceleration nods is decelerate distance S, its computation formula is (7) the F1 in type, F2- - the Fd of of feed speed after current feed speed and decelerate process end- - Td of of of poor of speed of decelerate curve model- - Sd of of of example slowdown time- - computation of of example decelerate distance is actual when decelerate is apart from S, needs example decelerate is apart from Sd to be able to pass next type to go out with leaving line means to be begged beforehand, store at increasing decelerate database in. (8) the Fi in type- - F of example decelerate curve (T) disperse takes T of Δ of the that be worth - - the time increment of numeric integral 4, last word is reasonable adding decelerate automatically to control is to assure numerical control machine tool (especially high speed machine tool) the important segment of dynamic function. What be based on fixed curve traditionally is automatic add decelerate to because lack is flexible,be controlled, assure not easily to add decelerate process and photograph of machine tool function to cooperate, the dynamic character that makes the machine tool moves hard is achieved optimal. What the article puts forward is flexible add decelerate to control a method, will add decelerate description and depart of systematic program photograph, make when change system adds decelerate performance, need to be revised independently only add decelerate to describe data, and do not need to modify program of numerical control system. Such, the user can press what his actual condition changes a system conveniently to add decelerate to control the rule, acquire property of trends of first-rate machine tool thereby. The means that offers is used successfully at the control of machine tool of homebred numerical control, offerred a new thinking to develop system of numerical control of construction of homebred and open mode. CNC Milling