Research On Hardware Interpolation Of Cubic B-spline Curve Based On FPGA

With the development of the FPGA programmable logic technology, varioussuperiorities such as low price, flexible development and excellent parallel computingability make it shows more and more advantages in CNC interpolation. Meanwhile, ascubic B-spline curve can represent different kinds of curve, curved surface accurately, itbecomes the key point of the current curve interpolation study. In this paper, themathematic theory of cubic B-spline curve interpolation algorithm is studied, and thenrealized and verified in the FPGA. The main work of this paper is as follow:Firstly, it briefly introduces the mathematic properties of cubic B-spline curve, and thespecific process of equal-parameter division interpolation algorithm and constant speedreal-time interpolation algorithm in details. All these two algorithms are simulated inMatlab. Through the simulation result, we analysis the advantages and disadvantagesbetween these two kinds of algorithm.By comparing these two algorithms, considering the realization in FPGA and thecombination of rough interpolation in ARM, the equal-parameter division interpolationalgorithm is chosen as the realization algorithm. It can guarantee not only high computingspeed, but also the machining accuracy and speed. Through the analysis of the algorithmcalculation process, it properly optimized the overall scheme of the interpolation module,and introduces how it is realized in the FPGA. Through the data conversion andstream-line calculation, it further improves the computational speed.Finally, through the interpolation calculation of different curves in the real numericalcontrol system’s PCB, it verifies the correctness of the design. Also the machining speedand accuracy of these curves are analyzed at the last of this thesis.