High Speed And High Precision Machining Technology For Complex Curve And Surface Based On NURBS

This paper based on National Science and Technology Major Project and National Natural Science Foundation as the background, using theoretical analysis, simulation and the actual test combination method, to improve high speed and, high accuracy maching technology of complex curves and surfaces as the goal, has the important theory significance and practical value. Mainly include the following contents:1、Aiming at the problem of the complex curve reconstruction for the NURBS curve, put forward the NURBS curve fitting algorithm and the fitting error control algorithm; Aiming at the problem of the complex surface reconstruction for NURBS surface, put forward NURBS surface fitting algorithm.2、Aiming at the problem of the trajectory control of NURBS curve interpolation, the NURBS curve interpolation is divided into two stages:rough interpolation and fine interpolation stages:rough interpolation adopted data sampled interpolation algorithm, and the rough interpolation stage involves the two coordinate space:the node vector parameter space and the interpolation trajectory space, the two space was related.In the node vector parameter space, studied several parameters dense algorithm, finally proposed own predictor-corrector-adjust difference algorithm; fine interpolation using DDA interpolation algorithm, took the tiny segment of rough interpolation further densification; finally use Matlab software in PC computer simulate the algorithm to verify the correctness of the algorithm.Aiming at the problem of the velocity control of NURBS curve interpolation, based on ladder-shaped acceleration and deceleration control algorithm and S curve acceleration and deceleration control algorithm, put forward own smooth S curve acceleration and deceleration control algorithm, and studied several incomplete smooth S curve acceleration and deceleration velocity planning; finally use Matlab software in PC computer simulate the algorithm to verify the correctness of the algorithm.3、Aiming at the problem of the NURBS curved surface five-axis tool path optimization problem, this paper divided into two case studies:for to be able to carry out flank milling NURBS ruled surface, using analytic algorithm gives the tool vector analytical solution and gives the analytical theory algorithm error; for not to be able to carry out flank milling NURBS ruled surface, using point milling in the paper, gives the NURBS surface point milling calculate procedure and calculate formula.4、Aiming at the problem of NURBS curve and surface interpolation algorithm platform, put forward embedded CNC platform based on Quantum Framework.When the hardware platform or software platform changed, only needs to write a few platform specific files for transplants, can be transplanted to the hardware platform and software platform, construct NURBS interpolator active object based on quantum framework.On the basis of the above research, simulates the NURBS curve and NURBS surface interpolation algorithm using the Matlab simulation software.carried actual NC machining experiments which was aimed on the NURBS curve and NURBS surface interpolation algorithm on maching centers and CNC hardware platform provide by college and institute, simulation and actual machining results proved the correctness of proposed NURBS curve and NURBS surface interpolation algorithm.