基于回转轮廓面法加工的全软件数控系统设计

发布时间：2018-07-06 10:37

本文选题：全软件数控系统 + 回转轮廓面法加工　；参考：《西安工业大学》2017年硕士论文

【摘要】：对于空间曲面,采用回转轮廓面法加工是一种新型线接触加工方法,它有效减少了刀具加工路径,提高了机械加工效率。普通数控系统只有曲线插补,没有曲面插补,因此必须采用全软件数控系统完成曲面插补程序的编写。这样也使数控系统的结构得到了简化,系统有了更好的灵活性,为数控系统以后能有更好的开放性奠定了基础。对于复杂曲面加工所存在的问题,本文设计的全软件数控系统硬件电路主要由X86架构PC机和标准I/O接口电路组成,软件平台采用具有源代码开放性和很好移植性的Linux操作系统。为了提高机械加工效率,采用轮廓面逼近法对凸型非直纹面的加工刀位进行规划。为了解决插补中断的实时性问题,提出了一种实时中断非线程化的方法,将普通中断的处理采用优先级不同的内核线程处理,从而达到对中断执行机制的改进。提出了一种快速DDA插补算法,它采用改变积分累加器溢出值的方法,使得DDA插补方法在直线和圆弧插补过程中的运算次数明显减少,用较长的插补周期完成了更短插补周期所要达到的最高进给速度,使复合插补的实时性问题得到了解决。采用Qt设计了系统界面,可实现工作模式的选择、图形加工显示、状态界面显示、控制开关按钮等基本功能。Linux中断执行机制改进之后,理论分析可以解决中断延迟和任务处理时间的难题,以满足数控系统实时性要求。对改进之后的DDA插补算法进行了实例验证,验证结果表示插补累加次数减少,缩短了插补周期,提高了数控系统的实时性。
[Abstract]:For the space surface, the rotary contour method is a new type of linear contact machining method, which can effectively reduce the cutting path and improve the machining efficiency. The general NC system has only curve interpolation and no surface interpolation, so it is necessary to complete the programming of surface interpolation with the full software NC system. In this way, the structure of CNC system is simplified, and the system has better flexibility, which lays the foundation for better openness of CNC system in the future. For the problems existing in complex surface machining, the hardware circuit of the whole software NC system is mainly composed of X86 frame PC and standard I / O interface circuit. The software platform adopts Linux operating system with open source code and good portability. In order to improve the machining efficiency, the contour surface approximation method is used to plan the cutting tool position of convex non-ruled surface. In order to solve the real-time problem of interpolation interrupt, a non-threading method of real-time interrupt is proposed. The kernel thread with different priority is used to deal with the common interrupt, so that the mechanism of interrupt execution can be improved. In this paper, a fast DDA interpolation algorithm is proposed. It uses the method of changing the overflow value of the integral accumulator to reduce the number of times of DDA interpolation in the process of straight line and arc interpolation. The maximum feed speed of the shorter interpolation period is achieved with a longer interpolation period, and the real-time problem of composite interpolation is solved. QT is used to design the system interface, which can realize the choice of working mode, graphical display, state interface display, control switch button and other basic functions. After the improvement of Linux interrupt execution mechanism, Theoretical analysis can solve the problem of interrupt delay and task processing time to meet the real-time requirements of CNC system. The improved DDA interpolation algorithm is verified by an example. The result shows that the interpolation accumulative times are reduced, the interpolation cycle is shortened, and the real-time performance of the NC system is improved.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG659

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