DSP and FPGA are applied mediumly in system of CNC Machining of large size laser
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- source:JUSTYN CNC Machining
The 1 analysis that adds decelerate division and computation are in bide one's time level, DSP will obtain primitive data from the computer. Machining level, DSP will undertake analyse and reasonable allocation add to these data, decelerate area. Graph 2 to add, decelerate area sketch map. Adding decelerate division is to use multistage the rate change with minor amplitude replaces bigger rate change. To large size or platform of high speed campaign, of electric machinery add, decelerate process is necessary. By the principle knowable, two plans institute surrounds area size equal, work namely a shift is equidistant. Nextpage is in before in the design that the pace enters algorithm of electric machinery drive, use 2 simple curves to undertake speed plans to close mostly. This kind plans to close although means is simple, but go up in large-scale campaign platform and cannot quite mature mix to the static friction force between mechanical component rotate the element such as the moment of inertia of the component, its run the effect and not ideal. This system is being added, in the computational process of decelerate area, the relation that quickens time through mixing speed and " S " form curve undertakes planning to close to get acceleration region rate, through the relation speed and slowdown time and instead " S " form curve undertakes planning to close getting decelerate region rate. Graph 3 to add, decelerate region rate - time plans to add up to a curve, curvilinear slope represents the acceleration with working mobile head. From the graph 3 visible, add, decelerate area place uses plan to add up to a curve not identical, decelerate area curve more " abrupt " . Because the effect of the element such as force of mechanical system attrition suffers in decelerate process,this is, electric machinery bear is lesser, can bear quicker decelerate procedure. Use " S " the advantage that form curve has planning to close basically has: (1) electric machinery transfers to advance from static condition in the process of condition, because static friction force exists between mechanical component each, can make electric machinery is started relatively gentlily, avoided to bump or lose the happening of stage appearance. (2) electric machinery is entered when running level smoothly, can use bigger acceleration to undertake speed promotes. But, as the addition of speed, the after-power of electric machinery will be reduced ceaselessly, answer right now ceaseless slow down accelerates a process. (3) electric machinery transfers from advancing condition in the decelerate process of static condition, this kind plans to add up to a method to be able to make electric machinery transfers smoothly, avoid to happen bump. 2.
The analysis of 2 complex graphs often exists in a complex graph a lot of discontinuous, irregular vector, if the fine of every vector decelerate arrives 0, will naturally affect treatment rate. So, before what analyse current vector jointly wanting when analysing this kind of graph, hind graphical circumstance, the initiative rate that calculates the included angle that gives each vector to machine this vector in order to decide and end career. The ultimate rate when next watches undertake for working head angle turns differring. 3, the in-house and logistic design of FPGA looks from the angle of DSP, FPGA machines module to be similar to a memory, DSP needs to write computation into this memory as a result only, the following job will be finished entirely by FPGA. Basically used distinct category data to run paralell in FPGA treatment module read take and pair the technology that memory group works alternately. 3.
1 data is collateral the only job that reads the data memory that takes a tradition to get processor of be confined to is characteristic, use sheet normally piece high capacity location, this kind of structure makes the system needs to expend many read take periodic ability to get a group of complete data. And the design form that the collateral job character of FPGA can break through this kind of tradition, in depositing distinct category data the location at independence. Want to check the address when defining data only can read together in full data is obtained in taking cycle. Apply this kind of means to be able to be in reading time is the least change while simplify process designing, also can make the structure of integral program more clear. Nextpage3.
2 pairs of memory hand in temporary substitute worker to make the market go up already some congener FPGA products are used mostly keep a data, job kind that carries out a data, this will produce halt when data is transmitted. Although this system used memory to regard treatment as the cache of data, but rely on this kind of means merely insoluble still problem, still can cause treatment halt when DSP keeps data. Graph 4 it is sketch map of pair of memory group structure, carrying out when the system among them when the data in a group of memory, DSP can keep computation another group of memory as a result. As a result of the operation speed of DSP far outclass machines speed, so double memory framework can assure to machine not by discontinuous. Graph 5 for flow chart of FPGA machine program. Visible, need to change memory form to memory group changing below neat premise in the address selection signal and address tally to clear. Right now, FPGA still will inform DSP with discontinuous form, make DSP OK the data with new stuff. 4, width of cloth is used in experimental conclusion experiment for 1.
The 2 dimension workbench of 2m × 1m, the 57HS22 that pace of axis of X, Y uses firm of thunder a place of strategic importance into electric machinery matchs with M860 driver. The step pitch horn of 57HS22 is 1.
8 degrees, rated electric current is 4A, maintain torsion for 2.
2N.
M, fixed position torsion is 700g.
Cm, electric machinery receives a law to use shunt-wound form in order to stress high speed performance. The rotational classics of electric machinery rotor drives working head to do linear exercise by tooth form belt after decelerate, rotor every rotate a week makes working head mobile 24mm. Parted to make a large number of tests to PLT file, DXF file and BMP file in the experiment, among them PLT file and DXF file are used at cut test, BMP file is used at carving a test. Graphical file conveys by PC software to this system, subsequently off line is machined, below cut mode, the treatment rate of long vector can exceed 20000mm/min smoothly, speed is machined to be able to exceed 30000mm/min below sculpture mode. After the complex figure that contains more than 130 thousand vector to is machined 5 times continuously, without the positional deviation with distinguishable naked eye. Because this system used DSP to undertake the graph is analysed, make a system right the processing capability of complex graph got very big rise. In the meantime, the structure that FPGA interior double memory works alternately also from go up at all problem of idle of the treatment in solving data to transmit a process. The experiment makes clear, this system has treatment rate capability of processing of fast, graph is strong, use handy and reliable wait for an advantage. CNC Milling CNC Machining